Tannic Acid Attenuates Quinolinic Acid-Induced Neurodysfunction by Modulating Oxidative Stress and Pump Activity In vitro

Tannic Acid Attenuates Quinolinic Acid-Induced Neurodysfunction by Modulating Oxidative Stress and Pump Activity In vitro | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Tannic Acid Attenuates Quinolinic Acid-Induced Neurodysfunction by Modulating Oxidative Stress and Pump Activity In vitro Ebenezer Morayo Ale, Richard-Harris Nsenreuti Boyi, Isioma Christain Okonta, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6990411/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The pathophysiology of neurodegenerative illnesses is largely dependent on oxidative stress and poor ion homeostasis, and these conditions represent a substantial worldwide health burden. Endogenous neurotoxic quinolinic acid (QA) is linked to neurodysfunction by inducing oxidative stress and interfering with sodium pump function. In a number of models, the polyphenolic molecule tannic acid (TA), which has strong antioxidant qualities, has demonstrated pharmacological effects in several diseased conditions. However, the neuroprotective effect of tannic acid is rather speculative and still very open for clarification. In the present study, an in vitro model was employed to examine the effect of tannic acid on deoxyribose degradation, lipid peroxidation, thiol status, antioxidant enzymes, and cerebral and spinal sodium pump in rat cerebral and spinal tissue homogenates treated with quinolinic acid (2 mM). Results revealed that quinolinic acid treatment led to a profound ( p < 0.05) degradation of deoxyribose, formation of thiobarbituric acid reactive substances, and marked reduction ( p < 0.05) in tissue level of free thiols. However, tannic acid treatment significantly ( p < 0.05) counteracted thiobarbituric acid reactive substances production, deoxyribose degradation and markedly increased ( p < 0.05) the thiol level of the cerebral and spinal tissue homogenates. Furthermore, quinolinic acid markedly ( p < 0.05) diminished the activities of cerebral and spinal antioxidant enzymes, such as catalase, superoxide dismutase, glutathione peroxidase, and glutathione S -transferase, and impaired the activities of cerebral and spinal sodium pump. Nonetheless, the activities of the antioxidant enzymes and pump were all raised in both the cerebral and spinal tissue homogenates upon tannic acid treatment. These findings justify the pharmacological action of tannic acid on quinolinic acid-induced neurotoxicity and suggest its potential use in the treatment of neurodegenerative diseases. Biological sciences/Biochemistry Biological sciences/Drug discovery Health sciences/Neurology Biological sciences/Neuroscience Antioxidants enzymes Neurodysfunction lipid peroxidation Na+/K+-ATPase Polyphenols thiols Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction A disease known as neurodysfunction occurs when an agent that is chemical, biological, or physical can negatively impact the structure or functionality of the central and peripheral nervous systems 1 . It happens when a person is exposed to a chemical, specifically a neurotoxin or neurotoxicant, which modifies the nervous system’s typical activity and damages neural tissue permanently or irreversibly 2 . Over time, this can damage or even kill neurons, which are the cells that send and process impulses in the brain and other parts of the nervous system. Organ transplants and pro-oxidant exposures, including radiation, specific medication regimens, recreational drug use, heavy metal exposure, bites from specific venomous snake species, pesticides 2,3 , specific industrial cleaning solvents 4 , fuels 5 , and certain naturally occurring substances, can all result in neurotoxicity. The onset of symptoms may come on quickly or later after exposure. These could include delusions, headaches, uncontrollably obsessive or compulsive behaviors, limb weakness or numbness, loss of memory, eyesight, and intellect, as well as cognitive and behavioral issues and sexual dysfunction. Neurological illnesses and neurodegenerative diseases are becoming increasingly a great menace to world health. For example, the World Health Organization (WHO) reported that over 55 million people worldwide suffered from dementia in 2019, and it is predicted that this figure will increase to approximately 139 million by 2050. Neural illnesses have been linked to oxidative stress, which is defined by an imbalance between antioxidant defense mechanisms and the formation of reactive oxygen species (ROS) 6 . Neurodegeneration, the progressive loss of neuronal structure or function brought on by neurotoxic chemicals, is the root cause of neurodegenerative disorders. Cell damage or death may result from such neuronal damage in the end. Amyotrophic lateral sclerosis, multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, multiple system atrophy, tauopathies, and prion disorders are examples of neurodegenerative diseases. Neurodegeneration arises at several levels of neuronal circuitry in the brain, from molecular to systemic. These conditions are regarded as incurable since there is no known method to stop the neurons’ ongoing deterioration. Numerous subcellular commonalities between these illnesses have been identified by biomedical research, such as increased cell death and abnormal protein assemblages (such as proteinopathy) 7,8 . These parallels imply that improvements in treatment for one neurodegenerative illness may also benefit others. Quinolinic acid is a dicarboxylic acid having a pyridine backbone that is also referred to as pyridine 2,3-dicarboxylic acid. It is a solid with no color. It is the kynurenine pathway’s metabolic precursor of niacin and a metabolite of tryptophan 9 . According to Guillemin et al. 10 , quinolinic acid exhibits a strong neurotoxic impact. Research has indicated that quinolinic acid may play a role in a variety of mental illnesses, as well as neurodegenerative brain processes and other ailments. Quinolinic acid is only generated by activated macrophages and microglia in the brain. Quinolinic acid has been classified as an endogenous excitotoxin since it is derived from the central nervous system and has the potential to seriously harm neurons 11 . According to recent studies, quinolinic acid can cause lipid peroxidation in the mammalian brain and spine, which may result in the production of free radicals 12 . When prooxidants cause lipid peroxidation, the membrane lipids are frequently subjected to oxidative damage from free radical attack. Several disorders, particularly neurodegenerative conditions like Parkinson’s disease, include lipid peroxidation as a key pathogenic mechanism. However, antioxidants can prevent or delay cellular damage despite these oxidative stress-related etiologies primarily because of their ability to scavenge free radicals. These low-molecular-weight antioxidants can safely interact with free radicals, stopping the chain reaction before it causes harm to important components. Glutathione, ubiquinol, and uric acid are a few examples of antioxidants that the body naturally produces during regular metabolism 13 . The diet contains other, milder antioxidants. Additionally, research in the fields of biochemistry and pharmacology has demonstrated the significant functions that polyphenols, such as tannic acid, play in the absorption and neutralization of free radicals, the quenching of singlet and triplet oxygen, and the breakdown of peroxides produced by pro-oxidants like QA 14 . Tannic acid 15 (Fig. 1 ) is a chemical compound found in practically all aerial plant tissues that has antioxidant properties and may promote good health. Considering the fact that neurological disorders and neurodegeneration are significantly influenced by oxidative stress 16–18 , tannic acid’s antioxidant ability as a naturally occurring polyphenolic molecule thus provides a fascinating avenue for further research into its possible neuroprotective properties and the body of evidence pointing to a connection between oxidative stress and quinolinic acid-induced neurotoxicity. However, little is known about how specifically tannic acid reduces this neurotoxicity. Therefore, this research was undertaken to evaluate the attenuating potential of tannic acid against quinolinic acid induced neurodysfuction in rat cerebral and spinal tissues. Materials and Methods Chemicals The following materials were purchased from Sigma (St. Louis, MO): tannic acid (97% purity, 403040-50G), thiobarbituric acid (TBA), 2-deoxyribose, quinolinic acid, sodium hydroxide, 5,5-dithiobis-2-nitrobenzoic acid (DTNB), trichloroacetic acid (TCA), acetate buffer, Tris-HCl buffer, sodium dodecyl sulphate (SDS), adenosine triphosphate (ATP), ouabain, and quinolinic acid (QA). The remaining chemicals were procured from regular commercial suppliers and were of analytical quality. Experimental Animals Fifteen male Wistar rats weighing between 200-250g were used for the experiment at Biochemistry Departmental Animal House, Federal University Wukari, Nigeria. During this period, they were maintained at room temperature and provided with standard feed, water and light cycle. This study was carried out accordance to standard guideline of the Committee on Care and Use of Experimental Animal Resources of Faculty of Pure and Applied Sciences and approved by Federal University Wukari, Nigeria with the approval number FUW/FPAS/23/021 and the study is reported in accordance with ARRIVE guidelines. Tissue Preparation The animals were given a light isofluorane anesthesia, decapitated, and their organs (the spine and brain) were removed before being promptly frozen and weighed. The organs were properly cleaned to remove any blood stain by rinsing them in cold 50 mM Tris-HCl buffer. The tissue was homogenized right away using a homogenizer in a cold, pH 7.4 (1/10, w/v) 50 mM Tris-HCl solution. The low-speed supernatant fraction, which was utilized for the tests, was obtained by cold centrifuging (at 4 0 C) the homogenate at 4000 ×g for ten minutes and kept frozen. Deoxyribose Degradation The amount of deoxyribose degradation was measured in accordance with published data 19 . Hydroxyl radicals break down deoxyribose and generate reactive compounds known as thiobarbituric acid (TBA). For 30 minutes, deoxyribose (2 mM) was incubated at 37°C with 50 mM potassium phosphate (pH 7.4), 2 mM QA to cause deoxyribose breakdown, and TA (concentration range of 0–10 µM). Following the incubation period, the tubes were heated for 20 minutes at 100°C upon addition of 0.4 ml of TBA 0.8% and 0.8 ml of TCA 2.8% and spectrophotometric measurements were made at 532 nm. Thiobarbituric Acid Reactive Species Assay By measuring TBARS (Thiobarbituric acid reactive species) using a modified Ohkawa et al. 20 technique, lipid peroxidation was measured. An aliquot of 100 µl of homogenate (S1) was incubated in a reaction system with 50 mM Tris-HCl buffer (pH 7.4), 100 µl of tissue homogenate, and QA (2 mM) for one hour at 37°C with tannic acid (final concentrations range of 0–10 µM). 200 µl of 8.1% SDS (Sodium Dodecyl Sulphate) was added to the reaction mixture containing S1 to initiate the color reaction. This was followed by the addition of 500 µl of pH 3.4 acetate buffer and 500 µl of 0.8% TBA. For thirty minutes, this combination was incubated at 100°C. TBARS production was detected under UV-visible light at 532 nm. Glutathione Level Following Ellman's 21 method of deproteinization with TCA (5% in 1 mmol EDTA), the levels of GSH in the brain and spinal cord were measured at 412 nm using Ellman's reagent. The evaluation of the pancreas’ antioxidant capability also made use of the deproteinized brain and spinal tissues. Antioxidant Enzymes Activities 100 µl of tissue homogenate was incubated for 1hour at 37°C in the presence of TA (final concentrations range of 0–10 µM), in a reaction system containing 50 mM Tris-HCl buffer (pH7.4), with QA (2 mM). The resulting aliquots were then used for the assay of catalase (CAT), glutathione S- transferase (GST), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities. Catalase Using the Aebi 22 approach, which entails tracking the disappearance of H 2 O 2 in the presence of the homogenate at 240 nm, the catalase activity was measured spectrophotometrically. In a solution containing 50 mM phosphate buffer, pH 7.0, an aliquot and the substrate (H 2 O 2 ) were added to a final concentration of 0.3 mM to start the enzymatic reaction. The units used to express the enzymatic activity were 1 U, which breaks down 1 µmol of H 2 O 2 per minute at pH 7 at 25°C. Glutathione S -transferase Activity The activity of glutathione S-transferase (GST) was measured in accordance with Habig 23 . In short, for a standard experiment, a suitable quantity of enzyme was added to a reaction mixture of 3 mL that included a final concentration of 100 mM potassium phosphate buffer (pH 6.5), 1 mM GSH, and 1 mM 1-chloro-2,4-dinitrobenzene (CDNB). Superoxide Dismutase Activity The nitrobluetetrazolium (NBT) method developed by Beauchamp and Fridovich 24 was used to measure SOD activity. O 2 reduces NBT to blue formazan, which absorbs strongly at 560 nm. This process is inhibited by the presence of SOD. The assay mixture was composed of 50 µl of aliquot, 1.5 mg/ml BSA, 0.75 mM NBT, 3 mM EDTA, and 3 mM xanthine in 0.05 M sodium carbonate buffer (pH 10.2). After adding 50 µl of xanthine oxidase (0.1 mg/ml) and letting it sit at room temperature for 30 minutes, the reaction was started. After adding 6 mM CuCl 2 to halt the reaction, the mixture was centrifuged for 10 minutes at 1,500 rpm and the absorbance of blue formazan in the supernatants was measured at 560 nm. Glutathione Peroxidase Activity Glutathione peroxidase (GPx) was measured using the Paglia and Valentine 25 method. 0.1 M phosphate buffer (pH 7.0), 1 mM EDTA, 10 mM glutathione (GSH), 1 mM NaN 3 , 1 unit of glutathione reductase, 1.5 mM NADPH, and 0.1 ml of homogenate were all included in the reaction mixture. Following a 10-minute incubation period at 37°C, 1 mM of H 2 O 2 was added to each sample. At 340 nm, the rate of NADPH oxidation was used to calculate GPx activity. Sodium Pump Assays An aliquot of S1 was utilized in the Na + /K + -ATPase activity tests. In a final volume of 500 µl, the reaction mixture included pro-oxidants [QA (2 mM)] and TA (final concentrations range of 0–10 µM), 3 mM MgCl, 125 mM NaCl, 20 mM KCl, and 50 mM Tris-HCl, all at pH 7.4 and incubated at 37 0 C for 30 min. A final dose of 3.0 mM of ATP was added to start the process. The same conditions were used for the controls, but ouabain (0.1 mM) was added. The Fiske and Subbarow 26 method was used to measure the amount of released inorganic phosphate (Pi). The difference between two assays was used to compute the Na + /K + -ATPase activity (with and without ouabain). Every experiment was carried out a minimum of three times, yielding comparable outcomes and the activity of enzyme was expressed as number of moles of phosphate (P i ) released min − 1 mg protein − 1 . Statistical Analysis The collected data were all presented as mean ± SEM of three independent experiments. When appropriate, Duncan's multiple range tests were conducted after the data were analyzed using an appropriate ANOVA and Graphpad Prism. At p < 0.05, means having distinct superscripts differ considerably. Results and Discussion Effects on Deoxyribose Degradation As displayed in Fig. 1 , quinolinic acid caused a profound degradation ( p < 0.05) of deoxyribose sugar. However, tannic acid exerted marked inhibitory effect ( p ˂0.05) on deoxyribose degradation in a concentration dependent manner. Effects on Lipid Peroxidation The results in Fig. 2 revealed that quinolinic acid induced a marked increase in lipid peroxidation in the cerebral and spinal tissue homogenates. However, the tannic acid elicited a marked inhibitory effect ( p ˂0.05) on lipid peroxidation in a concentration dependent manner compared to the control. Effects Glutathione Level The results in Fig. 3 revealed that quinolinic acid caused a profound decrease of GSH level in rat brain and spine homogenates. However, treatment with tannic acid raised the GSH level ( p ˂0.05) in a concentration dependent manner compared to the control. Effects on Na + /K + -ATPase Activity As shown in Fig. 4 quinolinic acid inhibited the activity of the cerebral and spinal Na + /K + -ATPase, but treatment with tannic acid restored Na + /K + -ATPase activity ( p ˂0.05) in a concentration dependent manner compared to the control. Effects on Antioxidant Enzymes Tables 1 and 2 shows the effects of tannic acid on antioxidants enzymes in QA treated cerebral and spinal tissue homogenates respectively. QA caused a marked depletion ( p < 0.05) in the level of SOD, CAT, GPx and GST. In the brain tissue homogenate (Table 1 ). However, treatment with tannic acid elicited a profound increase ( p < 0.05) in the activities of these enzymes. Similarly, as revealed in Table 2 , the activities of SOD, CAT, GPx, GST in the spinal tissue homogenate were profoundly declined ( p < 0.05) by QA, but the administration of TA exhibited substantial (p < 0.05) increase in their activities. Table 1 Effects of tannic acid on antioxidant enzymes activities in quinolinic acid (QA)-treated cerebral tissue homogenates of rats Treatment Tubes CAT SOD GPx GST A Control 647.11 ± 88.08 a 31.64 ± 8.37 a 31.21 ± 3.85 a 3.13 ± 0.09 a B QA 422.74 ± 85.26 b 13.57 ± 2.53 b 14.02 ± 2.17 b 0.97 ± 0.03 b C QA + 1 µM TA 438.53 ± 77.38 b 19.48 ± 2.99 c 17.84 ± 3.07 b 1.21 ± 0.06 c D QA + 2 µM TA 426.83 ± 69.29 b 19.86 ± 4.5 c 15.55 ± 2.53 b 1.19 ± 0.08 c E QA + 4 µM TA 522.28 ± 95.83 c 17.93 ± 4.41 c 21.91 ± 2.99 c 3.53 ± 0.51 d F QA + 6 µM TA 539.3I ± 83.05 cd 23.84 ± 3.83 d 26.51 ± 3.51 d 2.92 ± 0.22 a G QA + 10 µM TA 579.64 ± 65.28 d 27.59 ± 4.85 d 24.16 ± 2.57 cd 4.26 ± 0.35 e Data are shown as the mean ± standard deviation (SD) of three separate tests. At p < 0.05, means with distinct superscripts exhibit a significant difference. SOD = superoxide dismutase (nmol/min/mg protein); CAT = catalase (µmole/mg protein/min); GST = Glutathione S- transferase (µmole/mg protein/min); GPx = Glutathione peroxidase (µmole/mg protein/min) Table 2 Effects of tannic acid on antioxidant enzymes activities in quinolinic acid-treated spinal tissue homogenates of rats. Treatment Tubes CAT SOD GPx GST A Control 228.35 ± 31.93 a 7.84 ± 0.75 a 7.68 ± 0.59 a 0.55 ± 0.03 a B QA 121.53 ± 18.35 b 2.99 ± 0.53 b 2.07 ± 0.06 b 0.173 ± 0.07 b C QA + 1 µM TA 119.73 ± 13.53 b 3.65 ± 0.46 c 1.38 ± 0.10 b 0.39 ± 0.02 c D QA + 2 µM TA 144.63 ± 15.08 c 6.27 ± 0.46 d 6.22 ± 0.12 c 0.35 ± 0.04 c E QA + 4 µM TA 139.22 ± 12.83 c 4.14 ± 0.51 c 4.74 ± 0.58 d 0.33 ± 0.04 c F QA + 6 µM TA 128.63 ± 9.52 c 6.48 ± 0.29 d 6.85 ± 0.41 c 0.39 ± 0.01 ac G QA + 10 µM TA 194.11 ± 24.37 a 6.26 ± 0.39 d 6.65 ± 0.33 c 0.37 ± 0.02 c Data are shown as the mean ± standard deviation (SD) of three separate tests. At p < 0.05, means with distinct superscripts exhibit a significant difference. SOD = superoxide dismutase (nmol/min/mg protein); CAT = catalase (µmole/mg protein/min); GST = glutathione S- transferase (µmole/mg protein/min); GPx = glutathione peroxidase (µmole/mg protein/min) Tannic acid (Fig. 1 ), one of the many naturally occurring antioxidants, has been shown to have a variety of biological effects, such as antiviral, antibacterial, anti-inflammatory, antiallergic, antithrombotic, and vasodilatory properties 27 . Antioxidant activity is a basic characteristic essential to life, and it can lead to the development of antiaging, anticarcinogenic, and antimutagenic properties, among others 28 . Tannic acid and other phenolic compounds have antioxidant action primarily because of their redox characteristics, which enable them to function as hydrogen donors, reducing agents, and singlet oxygen quenchers. Furthermore, they might have the ability to chelate metals 29,30 . This research is necessary to uncover the mechanisms by which tannic ameliorates neurodysfuction, by investigating it effect on cerebral and spinal antioxidant indices and sodium pump activities of rat cerebral and spinal tissues. One of the components of DNA, deoxyribose, is released as cells die and their DNA breaks down 31–33 . Interaction with ROS can cause a wide range of oxidative modifications to DNA, such as damages to the deoxyribose moiety of the DNA double helix's sugar-phosphate backbone, nucleobase modifications within the sequence, single- and double-strand breaks and DNA-protein crosslinks 34 . During normal metabolic circumstances, these kinds of oxidative damage to DNA are typically repaired by the cells; but, during oxidative stress, the volume of DNA lesions exceeds the capacity of the repair process, leaving some DNA lesions unrepaired. These unrepaired DNA lesions have the potential to cause oxidative stress-related etiologies, such as neurodegenerative disorders. One metabolite of the kynurenine pathway that has been linked to the pathophysiology of neurodegenerative illnesses is quinolinic acid, which may be a neurotoxin. Concerns regarding its potential to contribute to neuronal injury are raised by its capacity to cause oxidative stress in neural tissues 17,18 . The mechanism of Quinolinic acid-induced damage is mediated by overactivation of glutamate receptors, as QUIN is a selective NMDA subtype of glutamate receptor agonist 35 . Figure 2 illustrates a significant ( p ˂0.05) increase in degradation of deoxyribose after quinolinic acid treatment of deoxyribose sugar. Therefore, quinolinic acid could cause the degradation of deoxyribose constituents of nucleic acid present in the brain and spinal tissue homogenates. However, treatment with tannic acid significantly inhibited ( p ˂0.05) the degradation of deoxyribose by QA. Hence, tannic acid could exhibit potent inhibitory actions against degradation of deoxyribose components of the nucleic acid in the rat brain and spinal tissue homogenates and this result is in tandem with the one demonstrated by Kade et al. 15 , that tannic acid inhibited degradation of the deoxyribose by ferrous sulphate (FeSO 4 ). One of the main mechanisms of CNS injury caused by free radicals is lipid peroxidation, which directly destroys neuronal membranes and produces a variety of downstream products that cause significant cellular damage. Highly reactive electrophilic aldehydes, such as malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE), the most prevalent product, and acrolein, the most reactive, are formed when free radicals attack polyunsaturated fatty acids (PUFAs) 36–38 . As displayed in Fig. 3 , quinolinic acid evoked a marked production of lipid peroxidation adducts ( p ˂0.05) in both brain and spinal tissue homogenates. Increased membrane stiffness decreased activity of membrane-bound enzymes (such as the sodium pump), damage to membrane receptors, and changed permeability are all consequences of peroxidation of membrane lipids 39,40 . Apart from causing harm to phospholipids, radicals can target membrane proteins directly and create crosslinks between proteins and lipids, which are linked to modifications in the integrity of the membrane. It is plausible to speculate that disruption of all the aforementioned functions exhibited by PUFAs and their metabolites, in conjunction with protein modification, impact neuronal homeostasis and thus contribute to brain and neuronal dysfunction. However, treatment with tannic acid exerted an inhibitory effect on the cerebral and spinal lipid peroxidation. Researchers have shown that the primary components with antioxidant and antiradical qualities are flavonoids and flavones, which include polyphenols like tannic acids 41 , which may be useful in the treatment of chronic diseases whose origin is connected to oxidative stress. This agrees with the findings of Azimullah et al. 42 that tannic acid mitigated ROS and MDA induced by rotenone. In many organisms including animals, glutathione (GSH) functions as an antioxidant. Important cellular constituents can be shielded from harm by glutathione from sources such heavy metals, peroxides, free radicals, and reactive oxygen species 43 . As shown in Fig. 4 , the delivery of QA to rat brain and spinal tissue homogenates resulted in a significant reduction ( p ˂0.05) in GSH levels. However, treatment with tannic acid markedly increased ( p ˂0.05) GSH levels. This suggests that by raising their level in the central nervous system, tannic acid may modulate the cellular antioxidant system in counteracting the oxidative attack elicited by QA. This also aligns with the work of Azimullah et al. 42 that tannic acid abolished the depletion of GSH induced by rotenone. Moreover, animal cells’ plasma membranes are maintained by the sodium pump, an enzyme that is membrane bound. The ability to adjust to shifting physiological and cellular stimuli depends on this enzyme 44 . This protein is highly produced by neurons and is responsible for maintaining the electrical potential required for the excitability of this tissue by using between 30 and 60% of the brain’s ATP reserve. Quinolinic acid profoundly inhibited the action of Na + / k + -ATPase in the homogenate of the brain and spine, as Fig. 5 illustrates. Conversely, treatment with tannic acid restored the activity of the enzyme at high concentrations. This result correlates with the one demonstrated by Kade et al. 45 , that tannic acid could profoundly restore ( p ˂0.05) the activity of Na + / K + -ATPase in the cerebral tissue homogenate following reduction of its activity by streptozotocin. Thus, this suggest that tannic acid could have some pharmacological effects on the central nervous system. A collection of antioxidant enzymes that can prevent oxidative damage brought on by pro-oxidants make up the antioxidant pool. SOD, CAT, GST, and GPx are some of these enzymes. First line of defense against injury mediated by reactive oxygen species (ROS) is formed by SOD 46 . These proteins lower the level of superoxide anion free radical (O 2 ), which damages cells at high concentrations, by catalyzing its dismutation into molecular oxygen and hydrogen peroxide (H 2 O 2 ). The GPx are a type of antioxidant enzymes that are related to heme-free thiol peroxidases, just like peroxidases. They help to reduce the toxicity of H 2 O 2 and organic hydroperoxides by catalyzing their reduction to water or matching alcohols 47 . Similarly, one of the most significant antioxidant enzymes is catalase. Almost all aerobic organisms include it. In a two-step procedure, catalase converts two molecules of hydrogen peroxide into one molecule of oxygen 48 and two molecules of water 49 . A family of multifunctional enzymes known as the GSTs is responsible for the well-established detoxification of electrophilic metabolites and xenobiotics 50–52 . The conjugation of a broad range of structurally different molecules with electrophilic carbon, nitrogen, or sulfur atoms to GSH is generally catalyzed by GSTs. This study further investigated how tannic acid could restore enzymatic antioxidants in the brain and spinal tissue homogenates after quinolinic acid had reduced their activity. Table 1 shows that QA administration profoundly impaired ( p ˂0.05) the activity of SOD in the cerebral tissue homogenate. Nevertheless, tannic acid treatment resulted in a significant ( p < 0.05) rise in the activity of the enzyme. Fridovich et al. 53 indicate that this response implies tannin may mitigate total oxidative stress by successfully restoring cellular defenses against superoxide radicals. Furthermore, quinolinic acid administration caused a significant drop ( p < 0.05) in CAT activity in the brain tissue homogenate. On the other hand, catalase activity is significantly increased ( p ~ 0.05) upon tannic acid treatment. According to Kade et al. 2013 45 , this points to a possible mechanism by which tannic acid supports hydrogen peroxide detoxification by protecting cells from oxidative damage. Furthermore, in cerebral tissue homogenate, tannic acid demonstrated a considerable ( p < 0.05) ability to restore GPx activity following its depletion caused by quinolinic acid. This suggests that tannic acid can help the body's defense mechanism against free radicals by encouraging the breakdown of lipid and other organic peroxides. Moreover, quinolinic acid significantly ( p < 0.05) reduced the cerebral tissue homogenate’s GST level. Tannic acid administration, however, demonstrated a profound (p < 0.05) rise in GST activity. In similar manner, as displayed in Table 2 , QA markedly diminished ( p ˂ 0.05) the activities of CAT, SOD, GST and GPx in the spinal tissue homogenate and this effect is significant ( p ˂0.05) when compared to the control. Nonetheless, tannic acid substantially abolished ( p ˂0.05) the detrimental effect of QA by evoking a marked increase ( p ˂0.05) in the activities of the spinal antioxidant enzymes. This reveals that tannic acid increases oxidative stress in order to support the antioxidant pool within cells by augmenting the efficacy of the antioxidant enzymes. Findings herein are similar to those of Azimullah et al. 42 that demonstrated that tannic acid mitigated the depletion antioxidants, SOD, CAT, and GSH, accompanied with profound MDA and NO. TA has quite a number of mechanisms by which it operates. It has a strong capacity to scavenge free radicals due to its polyhydroxy structure, which donates hydrogen atoms to neutralize ROS. In addition, TA chelates transition metals such as iron and zinc, which catalyze ROS formation via Fenton reactions 54 . Moreso, TA treatment was observed to reduce lipid peroxidation, prevent loss of endogenous antioxidants, and inhibit the release and synthesis of proinflammatory cytokines, in addition to the favorable modulation of apoptosis and autophagic pathways. TA also attenuated the activation of microglia and astrocytes along with preservation of dopaminergic neurons following reduced loss of dopaminergic neurodegeneration and inhibition of synaptic loss and α-Glutamate cytotoxicity 42 . Apparently, it is worth mentioning that tannic acid has the efficacy to counteract oxidative damage and ameliorate or restore sodium pump activity in neurological conditions. Conclusion The results here in revealed that tannic counteracted the detrimental effects of QA in rat cerebral and spinal tissue homogenates by restoring sodium potassium pump activity and modulating antioxidant indices. Consequently, it is rational to conclude that tannic acid could mitigate oxidative stress processes, redox and homoeostatic complication that characterize neurological diseases. Tannic acid could be considered for the treatment and management of neurodegenerative diseases due to its observed antioxidant and pharmacological activity. However, further investigation is required to determine the translational efficacy of tannic acid into clinical settings. Declarations Ethical statement This study was carried out accordance to standard guideline of the Committee on Care and Use of Experimental Animal Resources of Faculty of Pure and Applied Sciences and approved by Federal University Wukari, Nigeria with the approval number FUW/FPAS/23/021 and the study is reported in accordance with ARRIVE guidelines. Author Contribution E.M conceptualized and designed the research. R.N supervised, Data collection were performed by V.I. , O.E reviewed the work. S.O. carried out data analysis and material preparation. Visualization and resources procurement was carried out by M.A., R.Y. and D.M carried out project administration, while E.M. also wrote the first draft of the manuscript. All authors commented on previous versions of the manuscript. All authors have read and approved the final manuscript. Acknowledgement We would like to express our sincere gratitude to all authors for their invaluable contributions to this manuscript. 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Tannic acid confers neuroprotection via Zn²⁺ chelation in an ischemic stroke model. International Journal of Molecular Sciences , 23(18), 10823. https://doi.org/10.3390/ijms231810823 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6990411","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":481279901,"identity":"e98df0ae-ef42-400f-9cc6-b133dacde9ca","order_by":0,"name":"Ebenezer Morayo Ale","email":"data:image/png;base64,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","orcid":"","institution":"Federal University Wukari","correspondingAuthor":true,"prefix":"","firstName":"Ebenezer","middleName":"Morayo","lastName":"Ale","suffix":""},{"id":481279902,"identity":"9de990f1-dc12-4903-a978-dfccc770ea8c","order_by":1,"name":"Richard-Harris Nsenreuti Boyi","email":"","orcid":"","institution":"Federal University Wukari","correspondingAuthor":false,"prefix":"","firstName":"Richard-Harris","middleName":"Nsenreuti","lastName":"Boyi","suffix":""},{"id":481279903,"identity":"17cb34f5-c824-4a19-a74b-a37179052dc0","order_by":2,"name":"Isioma Christain Okonta","email":"","orcid":"","institution":"University of Delta","correspondingAuthor":false,"prefix":"","firstName":"Isioma","middleName":"Christain","lastName":"Okonta","suffix":""},{"id":481279904,"identity":"c9b62ea0-2128-45c3-9abe-d207a1864bf2","order_by":3,"name":"Victoria Ifeoluwa Ayo","email":"","orcid":"","institution":"Federal University Wukari","correspondingAuthor":false,"prefix":"","firstName":"Victoria","middleName":"Ifeoluwa","lastName":"Ayo","suffix":""},{"id":481279905,"identity":"1f0c5d51-3964-40e5-9403-af53ffda2a84","order_by":4,"name":"Steve Osagie Asuelimen","email":"","orcid":"","institution":"Federal University Wukari","correspondingAuthor":false,"prefix":"","firstName":"Steve","middleName":"Osagie","lastName":"Asuelimen","suffix":""},{"id":481279908,"identity":"0d198356-a39a-48df-9f0f-64e9ba7976fb","order_by":5,"name":"Ojochenemi Ejeh Yakubu","email":"","orcid":"","institution":"Federal University Wukari","correspondingAuthor":false,"prefix":"","firstName":"Ojochenemi","middleName":"Ejeh","lastName":"Yakubu","suffix":""},{"id":481279910,"identity":"316841fa-b8f4-4ebb-b070-8b8ef4dbfec1","order_by":6,"name":"Mulikat Adenike Adewole","email":"","orcid":"","institution":"University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Mulikat","middleName":"Adenike","lastName":"Adewole","suffix":""},{"id":481279912,"identity":"05aaf03d-147e-4e09-8d54-de862a504b17","order_by":7,"name":"Rimamsanati Yohanna Nathan","email":"","orcid":"","institution":"Federal University Wukari","correspondingAuthor":false,"prefix":"","firstName":"Rimamsanati","middleName":"Yohanna","lastName":"Nathan","suffix":""},{"id":481279914,"identity":"ce7135ae-1bcc-4d74-b972-74355e2e634f","order_by":8,"name":"Dyelshak Miracle Lekyes","email":"","orcid":"","institution":"Federal University Wukari","correspondingAuthor":false,"prefix":"","firstName":"Dyelshak","middleName":"Miracle","lastName":"Lekyes","suffix":""}],"badges":[],"createdAt":"2025-06-27 09:53:36","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6990411/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6990411/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":86332131,"identity":"ce1c6ad3-816b-4c1b-8e20-38108c7d4a23","added_by":"auto","created_at":"2025-07-09 12:25:26","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":101752,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eChemical structure of tannic acid\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e15\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6990411/v1/6515b2fb8a81bc0cc783cb21.png"},{"id":86332144,"identity":"95f6ca2c-9d81-46dd-8186-7235b094156a","added_by":"auto","created_at":"2025-07-09 12:25:27","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":97738,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of tannic acid on quinolinic acid (QA)-induced deoxyribose degradation. Data are shown as the mean ± standard deviation (SD) of three separate tests. At \u003cem\u003ep\u003c/em\u003e \u0026lt;0.05 means with distinct superscripts exhibit a significant difference\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6990411/v1/94921f4883eb7cf800adec42.png"},{"id":86332423,"identity":"178a84a8-00e8-4b80-8731-81a7fc595df7","added_by":"auto","created_at":"2025-07-09 12:33:27","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":100595,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of tannic acid on quinolinic acid (QA)-induced lipid peroxidation in cerebral and spinal tissue homogenates of rats. Data are shown as the mean ± standard deviation (SD) of three separate tests. At \u003cem\u003ep \u003c/em\u003e\u0026lt;0.05 means with distinct superscripts exhibit a significant difference.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6990411/v1/eb553c7120d1127a76601c82.png"},{"id":86332143,"identity":"fb77da34-3a8c-4a79-98b5-b0c99f26f6aa","added_by":"auto","created_at":"2025-07-09 12:25:27","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":87474,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of tannic acid on GSH level in quinolinic acid-treated cerebral and spinal tissue homogenates of rats. Data are shown as the mean ± standard deviation (SD) of three separate tests. At \u003cem\u003ep\u003c/em\u003e \u0026lt;0.05 means with distinct superscripts exhibit a significant difference\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6990411/v1/ae70152c2fabf63f14e2dafe.png"},{"id":86332138,"identity":"235334ba-4019-43ad-a806-4e5164a6d7a0","added_by":"auto","created_at":"2025-07-09 12:25:27","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":90677,"visible":true,"origin":"","legend":"\u003cp\u003eEffects of tannic acid on sodium pump activity in quinolinic acid-treated cerebral and spinal tissue homogenates of rats. Data are shown as the mean ± standard deviation (SD) of three separate tests. At \u003cem\u003ep\u003c/em\u003e \u0026lt;0.05 means with distinct superscripts exhibit a significant difference\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6990411/v1/1f6cfb35cb7628858fdec0d9.png"},{"id":96882695,"identity":"490b5eba-c39f-4f31-aeaf-5d0925d40e97","added_by":"auto","created_at":"2025-11-27 07:24:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1202449,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6990411/v1/2e4cad3e-a46c-40da-83c2-6d233111ad77.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Tannic Acid Attenuates Quinolinic Acid-Induced Neurodysfunction by Modulating Oxidative Stress and Pump Activity In vitro","fulltext":[{"header":"Introduction","content":"\u003cp\u003eA disease known as neurodysfunction occurs when an agent that is chemical, biological, or physical can negatively impact the structure or functionality of the central and peripheral nervous systems\u003csup\u003e\u003cb\u003e1\u003c/b\u003e\u003c/sup\u003e. It happens when a person is exposed to a chemical, specifically a neurotoxin or neurotoxicant, which modifies the nervous system\u0026rsquo;s typical activity and damages neural tissue permanently or irreversibly\u003csup\u003e\u003cb\u003e2\u003c/b\u003e\u003c/sup\u003e. Over time, this can damage or even kill neurons, which are the cells that send and process impulses in the brain and other parts of the nervous system. Organ transplants and pro-oxidant exposures, including radiation, specific medication regimens, recreational drug use, heavy metal exposure, bites from specific venomous snake species, pesticides\u003csup\u003e\u003cb\u003e2,3\u003c/b\u003e\u003c/sup\u003e, specific industrial cleaning solvents\u003csup\u003e\u003cb\u003e4\u003c/b\u003e\u003c/sup\u003e, fuels\u003csup\u003e\u003cb\u003e5\u003c/b\u003e\u003c/sup\u003e, and certain naturally occurring substances, can all result in neurotoxicity.\u003c/p\u003e\u003cp\u003eThe onset of symptoms may come on quickly or later after exposure. These could include delusions, headaches, uncontrollably obsessive or compulsive behaviors, limb weakness or numbness, loss of memory, eyesight, and intellect, as well as cognitive and behavioral issues and sexual dysfunction. Neurological illnesses and neurodegenerative diseases are becoming increasingly a great menace to world health. For example, the World Health Organization (WHO) reported that over 55\u0026nbsp;million people worldwide suffered from dementia in 2019, and it is predicted that this figure will increase to approximately 139\u0026nbsp;million by 2050. Neural illnesses have been linked to oxidative stress, which is defined by an imbalance between antioxidant defense mechanisms and the formation of reactive oxygen species (ROS)\u003csup\u003e\u003cb\u003e6\u003c/b\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eNeurodegeneration, the progressive loss of neuronal structure or function brought on by neurotoxic chemicals, is the root cause of neurodegenerative disorders. Cell damage or death may result from such neuronal damage in the end. Amyotrophic lateral sclerosis, multiple sclerosis, Parkinson\u0026rsquo;s disease, Alzheimer\u0026rsquo;s disease, Huntington\u0026rsquo;s disease, multiple system atrophy, tauopathies, and prion disorders are examples of neurodegenerative diseases. Neurodegeneration arises at several levels of neuronal circuitry in the brain, from molecular to systemic. These conditions are regarded as incurable since there is no known method to stop the neurons\u0026rsquo; ongoing deterioration. Numerous subcellular commonalities between these illnesses have been identified by biomedical research, such as increased cell death and abnormal protein assemblages (such as proteinopathy)\u003csup\u003e\u003cb\u003e7,8\u003c/b\u003e\u003c/sup\u003e. These parallels imply that improvements in treatment for one neurodegenerative illness may also benefit others.\u003c/p\u003e\u003cp\u003eQuinolinic acid is a dicarboxylic acid having a pyridine backbone that is also referred to as pyridine 2,3-dicarboxylic acid. It is a solid with no color. It is the kynurenine pathway\u0026rsquo;s metabolic precursor of niacin and a metabolite of tryptophan\u003csup\u003e\u003cb\u003e9\u003c/b\u003e\u003c/sup\u003e. According to Guillemin et al. \u003csup\u003e\u003cb\u003e10\u003c/b\u003e\u003c/sup\u003e, quinolinic acid exhibits a strong neurotoxic impact. Research has indicated that quinolinic acid may play a role in a variety of mental illnesses, as well as neurodegenerative brain processes and other ailments. Quinolinic acid is only generated by activated macrophages and microglia in the brain. Quinolinic acid has been classified as an endogenous excitotoxin since it is derived from the central nervous system and has the potential to seriously harm neurons\u003csup\u003e\u003cb\u003e11\u003c/b\u003e\u003c/sup\u003e. According to recent studies, quinolinic acid can cause lipid peroxidation in the mammalian brain and spine, which may result in the production of free radicals\u003csup\u003e\u003cb\u003e12\u003c/b\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eWhen prooxidants cause lipid peroxidation, the membrane lipids are frequently subjected to oxidative damage from free radical attack. Several disorders, particularly neurodegenerative conditions like Parkinson\u0026rsquo;s disease, include lipid peroxidation as a key pathogenic mechanism. However, antioxidants can prevent or delay cellular damage despite these oxidative stress-related etiologies primarily because of their ability to scavenge free radicals. These low-molecular-weight antioxidants can safely interact with free radicals, stopping the chain reaction before it causes harm to important components. Glutathione, ubiquinol, and uric acid are a few examples of antioxidants that the body naturally produces during regular metabolism\u003csup\u003e\u003cb\u003e13\u003c/b\u003e\u003c/sup\u003e. The diet contains other, milder antioxidants. Additionally, research in the fields of biochemistry and pharmacology has demonstrated the significant functions that polyphenols, such as tannic acid, play in the absorption and neutralization of free radicals, the quenching of singlet and triplet oxygen, and the breakdown of peroxides produced by pro-oxidants like QA\u003csup\u003e\u003cb\u003e14\u003c/b\u003e\u003c/sup\u003e. Tannic acid\u003csup\u003e\u003cb\u003e15\u003c/b\u003e\u003c/sup\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) is a chemical compound found in practically all aerial plant tissues that has antioxidant properties and may promote good health.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eConsidering the fact that neurological disorders and neurodegeneration are significantly influenced by oxidative stress\u003csup\u003e\u003cb\u003e16\u0026ndash;18\u003c/b\u003e\u003c/sup\u003e, tannic acid\u0026rsquo;s antioxidant ability as a naturally occurring polyphenolic molecule thus provides a fascinating avenue for further research into its possible neuroprotective properties and the body of evidence pointing to a connection between oxidative stress and quinolinic acid-induced neurotoxicity. However, little is known about how specifically tannic acid reduces this neurotoxicity. Therefore, this research was undertaken to evaluate the attenuating potential of tannic acid against quinolinic acid induced neurodysfuction in rat cerebral and spinal tissues.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e\u003cb\u003eChemicals\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe following materials were purchased from Sigma (St. Louis, MO): tannic acid (97% purity, 403040-50G), thiobarbituric acid (TBA), 2-deoxyribose, quinolinic acid, sodium hydroxide, 5,5-dithiobis-2-nitrobenzoic acid (DTNB), trichloroacetic acid (TCA), acetate buffer, Tris-HCl buffer, sodium dodecyl sulphate (SDS), adenosine triphosphate (ATP), ouabain, and quinolinic acid (QA). The remaining chemicals were procured from regular commercial suppliers and were of analytical quality.\u003c/p\u003e\u003cp\u003e\u003cb\u003eExperimental Animals\u003c/b\u003e\u003c/p\u003e\u003cp\u003eFifteen male Wistar rats weighing between 200-250g were used for the experiment at Biochemistry Departmental Animal House, Federal University Wukari, Nigeria. During this period, they were maintained at room temperature and provided with standard feed, water and light cycle. This study was carried out accordance to standard guideline of the Committee on Care and Use of Experimental Animal Resources of Faculty of Pure and Applied Sciences and approved by Federal University Wukari, Nigeria with the approval number FUW/FPAS/23/021 and the study is reported in accordance with ARRIVE guidelines.\u003c/p\u003e\u003cp\u003e\u003cb\u003eTissue Preparation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe animals were given a light isofluorane anesthesia, decapitated, and their organs (the spine and brain) were removed before being promptly frozen and weighed. The organs were properly cleaned to remove any blood stain by rinsing them in cold 50 mM Tris-HCl buffer. The tissue was homogenized right away using a homogenizer in a cold, pH 7.4 (1/10, w/v) 50 mM Tris-HCl solution. The low-speed supernatant fraction, which was utilized for the tests, was obtained by cold centrifuging (at 4 \u003csup\u003e0\u003c/sup\u003eC) the homogenate at 4000 \u0026times;g for ten minutes and kept frozen.\u003c/p\u003e\u003cp\u003e\u003cb\u003eDeoxyribose Degradation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe amount of deoxyribose degradation was measured in accordance with published data\u003csup\u003e\u003cb\u003e19\u003c/b\u003e\u003c/sup\u003e. Hydroxyl radicals break down deoxyribose and generate reactive compounds known as thiobarbituric acid (TBA). For 30 minutes, deoxyribose (2 mM) was incubated at 37\u0026deg;C with 50 mM potassium phosphate (pH 7.4), 2 mM QA to cause deoxyribose breakdown, and TA (concentration range of 0\u0026ndash;10 \u0026micro;M). Following the incubation period, the tubes were heated for 20 minutes at 100\u0026deg;C upon addition of 0.4 ml of TBA 0.8% and 0.8 ml of TCA 2.8% and spectrophotometric measurements were made at 532 nm.\u003c/p\u003e\u003cp\u003e\u003cb\u003eThiobarbituric Acid Reactive Species Assay\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBy measuring TBARS (Thiobarbituric acid reactive species) using a modified Ohkawa et al.\u003csup\u003e\u003cb\u003e20\u003c/b\u003e\u003c/sup\u003e technique, lipid peroxidation was measured. An aliquot of 100 \u0026micro;l of homogenate (S1) was incubated in a reaction system with 50 mM Tris-HCl buffer (pH 7.4), 100 \u0026micro;l of tissue homogenate, and QA (2 mM) for one hour at 37\u0026deg;C with tannic acid (final concentrations range of 0\u0026ndash;10 \u0026micro;M). 200 \u0026micro;l of 8.1% SDS (Sodium Dodecyl Sulphate) was added to the reaction mixture containing S1 to initiate the color reaction. This was followed by the addition of 500 \u0026micro;l of pH 3.4 acetate buffer and 500 \u0026micro;l of 0.8% TBA. For thirty minutes, this combination was incubated at 100\u0026deg;C. TBARS production was detected under UV-visible light at 532 nm.\u003c/p\u003e\u003cp\u003e\u003cb\u003eGlutathione Level\u003c/b\u003e\u003c/p\u003e\u003cp\u003eFollowing Ellman's\u003csup\u003e\u003cb\u003e21\u003c/b\u003e\u003c/sup\u003e method of deproteinization with TCA (5% in 1 mmol EDTA), the levels of GSH in the brain and spinal cord were measured at 412 nm using Ellman's reagent. The evaluation of the pancreas\u0026rsquo; antioxidant capability also made use of the deproteinized brain and spinal tissues.\u003c/p\u003e\u003cp\u003e\u003cb\u003eAntioxidant Enzymes Activities\u003c/b\u003e\u003c/p\u003e\u003cp\u003e100 \u0026micro;l of tissue homogenate was incubated for 1hour at 37\u0026deg;C in the presence of TA (final concentrations range of 0\u0026ndash;10 \u0026micro;M), in a reaction system containing 50 mM Tris-HCl buffer (pH7.4), with QA (2 mM). The resulting aliquots were then used for the assay of catalase (CAT), glutathione \u003cem\u003eS-\u003c/em\u003etransferase (GST), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities.\u003c/p\u003e\u003cp\u003e\u003cb\u003eCatalase\u003c/b\u003e\u003c/p\u003e\u003cp\u003eUsing the Aebi\u003csup\u003e\u003cb\u003e22\u003c/b\u003e\u003c/sup\u003e approach, which entails tracking the disappearance of H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e in the presence of the homogenate at 240 nm, the catalase activity was measured spectrophotometrically. In a solution containing 50 mM phosphate buffer, pH 7.0, an aliquot and the substrate (H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e) were added to a final concentration of 0.3 mM to start the enzymatic reaction. The units used to express the enzymatic activity were 1 U, which breaks down 1 \u0026micro;mol of H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e per minute at pH 7 at 25\u0026deg;C.\u003c/p\u003e\u003cp\u003e\u003cb\u003eGlutathione\u003c/b\u003e \u003cb\u003eS\u003c/b\u003e\u003cb\u003e-transferase Activity\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe activity of glutathione S-transferase (GST) was measured in accordance with Habig\u003csup\u003e\u003cb\u003e23\u003c/b\u003e\u003c/sup\u003e. In short, for a standard experiment, a suitable quantity of enzyme was added to a reaction mixture of 3 mL that included a final concentration of 100 mM potassium phosphate buffer (pH 6.5), 1 mM GSH, and 1 mM 1-chloro-2,4-dinitrobenzene (CDNB).\u003c/p\u003e\u003cp\u003e\u003cb\u003eSuperoxide Dismutase Activity\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe nitrobluetetrazolium (NBT) method developed by Beauchamp and Fridovich\u003csup\u003e\u003cb\u003e24\u003c/b\u003e\u003c/sup\u003e was used to measure SOD activity. O\u003csub\u003e2\u003c/sub\u003e reduces NBT to blue formazan, which absorbs strongly at 560 nm. This process is inhibited by the presence of SOD. The assay mixture was composed of 50 \u0026micro;l of aliquot, 1.5 mg/ml BSA, 0.75 mM NBT, 3 mM EDTA, and 3 mM xanthine in 0.05 M sodium carbonate buffer (pH 10.2). After adding 50 \u0026micro;l of xanthine oxidase (0.1 mg/ml) and letting it sit at room temperature for 30 minutes, the reaction was started. After adding 6 mM CuCl\u003csub\u003e2\u003c/sub\u003e to halt the reaction, the mixture was centrifuged for 10 minutes at 1,500 rpm and the absorbance of blue formazan in the supernatants was measured at 560 nm.\u003c/p\u003e\u003cp\u003e\u003cb\u003eGlutathione Peroxidase Activity\u003c/b\u003e\u003c/p\u003e\u003cp\u003eGlutathione peroxidase (GPx) was measured using the Paglia and Valentine\u003csup\u003e\u003cb\u003e25\u003c/b\u003e\u003c/sup\u003e method. 0.1 M phosphate buffer (pH 7.0), 1 mM EDTA, 10 mM glutathione (GSH), 1 mM NaN\u003csub\u003e3\u003c/sub\u003e, 1 unit of glutathione reductase, 1.5 mM NADPH, and 0.1 ml of homogenate were all included in the reaction mixture. Following a 10-minute incubation period at 37\u0026deg;C, 1 mM of H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e was added to each sample. At 340 nm, the rate of NADPH oxidation was used to calculate GPx activity.\u003c/p\u003e\u003cp\u003e\u003cb\u003eSodium Pump Assays\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAn aliquot of S1 was utilized in the Na\u003csup\u003e+\u003c/sup\u003e/K\u003csup\u003e+\u003c/sup\u003e -ATPase activity tests. In a final volume of 500 \u0026micro;l, the reaction mixture included pro-oxidants [QA (2 mM)] and TA (final concentrations range of 0\u0026ndash;10 \u0026micro;M), 3 mM MgCl, 125 mM NaCl, 20 mM KCl, and 50 mM Tris-HCl, all at pH 7.4 and incubated at 37 \u003csup\u003e0\u003c/sup\u003eC for 30 min. A final dose of 3.0 mM of ATP was added to start the process. The same conditions were used for the controls, but ouabain (0.1 mM) was added. The Fiske and Subbarow\u003csup\u003e\u003cb\u003e26\u003c/b\u003e\u003c/sup\u003e method was used to measure the amount of released inorganic phosphate (Pi). The difference between two assays was used to compute the Na\u003csup\u003e+\u003c/sup\u003e/K\u003csup\u003e+\u003c/sup\u003e -ATPase activity (with and without ouabain). Every experiment was carried out a minimum of three times, yielding comparable outcomes and the activity of enzyme was expressed as number of moles of phosphate (P\u003csub\u003ei\u003c/sub\u003e) released min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003emg protein\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eThe collected data were all presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SEM of three independent experiments. When appropriate, Duncan's multiple range tests were conducted after the data were analyzed using an appropriate ANOVA and Graphpad Prism. At p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, means having distinct superscripts differ considerably.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003e\u003cb\u003eEffects on Deoxyribose Degradation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAs displayed in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, quinolinic acid caused a profound degradation (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) of deoxyribose sugar. However, tannic acid exerted marked inhibitory effect (\u003cem\u003ep\u003c/em\u003e ˂0.05) on deoxyribose degradation in a concentration dependent manner.\u003c/p\u003e\u003cp\u003e\u003cb\u003eEffects on Lipid Peroxidation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe results in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e revealed that quinolinic acid induced a marked increase in lipid peroxidation in the cerebral and spinal tissue homogenates. However, the tannic acid elicited a marked inhibitory effect (\u003cem\u003ep\u003c/em\u003e ˂0.05) on lipid peroxidation in a concentration dependent manner compared to the control.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eEffects Glutathione Level\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe results in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e revealed that quinolinic acid caused a profound decrease of GSH level in rat brain and spine homogenates. However, treatment with tannic acid raised the GSH level (\u003cem\u003ep\u003c/em\u003e ˂0.05) in a concentration dependent manner compared to the control.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eEffects on Na\u003c/b\u003e\u003csup\u003e\u003cb\u003e+\u003c/b\u003e\u003c/sup\u003e\u003cb\u003e/K\u003c/b\u003e\u003csup\u003e\u003cb\u003e+\u003c/b\u003e\u003c/sup\u003e\u003cb\u003e-ATPase Activity\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e quinolinic acid inhibited the activity of the cerebral and spinal Na\u003csup\u003e\u003cem\u003e+\u003c/em\u003e\u003c/sup\u003e/K\u003csup\u003e\u003cem\u003e+\u003c/em\u003e\u003c/sup\u003e-ATPase, but treatment with tannic acid restored Na\u003csup\u003e\u003cem\u003e+\u003c/em\u003e\u003c/sup\u003e/K\u003csup\u003e\u003cem\u003e+\u003c/em\u003e\u003c/sup\u003e-ATPase activity (\u003cem\u003ep\u003c/em\u003e ˂0.05) in a concentration dependent manner compared to the control.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eEffects on Antioxidant Enzymes\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTables\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the effects of tannic acid on antioxidants enzymes in QA treated cerebral and spinal tissue homogenates respectively. QA caused a marked depletion (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in the level of SOD, CAT, GPx and GST. In the brain tissue homogenate (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). However, treatment with tannic acid elicited a profound increase (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in the activities of these enzymes. Similarly, as revealed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, the activities of SOD, CAT, GPx, GST in the spinal tissue homogenate were profoundly declined (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) by QA, but the administration of TA exhibited substantial (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) increase in their activities.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eEffects of tannic acid on antioxidant enzymes activities in quinolinic acid (QA)-treated cerebral tissue homogenates of rats\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTreatment Tubes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCAT\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSOD\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eGPx\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eGST\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA\u003c/b\u003e Control\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e647.11\u0026thinsp;\u0026plusmn;\u0026thinsp;88.08\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31.64\u0026thinsp;\u0026plusmn;\u0026thinsp;8.37\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e31.21\u0026thinsp;\u0026plusmn;\u0026thinsp;3.85\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.09\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB\u003c/b\u003e QA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e422.74\u0026thinsp;\u0026plusmn;\u0026thinsp;85.26\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13.57\u0026thinsp;\u0026plusmn;\u0026thinsp;2.53\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e14.02\u0026thinsp;\u0026plusmn;\u0026thinsp;2.17\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.97\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eC\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;1 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e438.53\u0026thinsp;\u0026plusmn;\u0026thinsp;77.38\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19.48\u0026thinsp;\u0026plusmn;\u0026thinsp;2.99\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e17.84\u0026thinsp;\u0026plusmn;\u0026thinsp;3.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eD\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;2 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e426.83\u0026thinsp;\u0026plusmn;\u0026thinsp;69.29\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e19.86\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e15.55\u0026thinsp;\u0026plusmn;\u0026thinsp;2.53\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e1.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eE\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;4 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e522.28\u0026thinsp;\u0026plusmn;\u0026thinsp;95.83\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e17.93\u0026thinsp;\u0026plusmn;\u0026thinsp;4.41\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e21.91\u0026thinsp;\u0026plusmn;\u0026thinsp;2.99\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eF\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;6 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e539.3I\u0026thinsp;\u0026plusmn;\u0026thinsp;83.05\u003csup\u003ecd\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23.84\u0026thinsp;\u0026plusmn;\u0026thinsp;3.83\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e26.51\u0026thinsp;\u0026plusmn;\u0026thinsp;3.51\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e2.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eG\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;10 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e579.64\u0026thinsp;\u0026plusmn;\u0026thinsp;65.28\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e27.59\u0026thinsp;\u0026plusmn;\u0026thinsp;4.85\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e24.16\u0026thinsp;\u0026plusmn;\u0026thinsp;2.57\u003csup\u003ecd\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35\u003csup\u003ee\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eData are shown as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) of three separate tests. At p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, means with distinct superscripts exhibit a significant difference. SOD\u0026thinsp;=\u0026thinsp;superoxide dismutase (nmol/min/mg protein); CAT\u0026thinsp;=\u0026thinsp;catalase (\u0026micro;mole/mg protein/min); GST\u0026thinsp;=\u0026thinsp;Glutathione \u003cem\u003eS-\u003c/em\u003etransferase (\u0026micro;mole/mg protein/min); GPx\u0026thinsp;=\u0026thinsp;Glutathione peroxidase (\u0026micro;mole/mg protein/min)\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eEffects of tannic acid on antioxidant enzymes activities in quinolinic acid-treated spinal tissue homogenates of rats.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTreatment Tubes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCAT\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSOD\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eGPx\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eGST\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eA\u003c/b\u003e Control\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e228.35\u0026thinsp;\u0026plusmn;\u0026thinsp;31.93\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e7.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.75\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e7.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.03\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eB\u003c/b\u003e QA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e121.53\u0026thinsp;\u0026plusmn;\u0026thinsp;18.35\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.99\u0026thinsp;\u0026plusmn;\u0026thinsp;0.53\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.07\u0026thinsp;\u0026plusmn;\u0026thinsp;0.06\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.173\u0026thinsp;\u0026plusmn;\u0026thinsp;0.07\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eC\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;1 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e119.73\u0026thinsp;\u0026plusmn;\u0026thinsp;13.53\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.46\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eD\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;2 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e144.63\u0026thinsp;\u0026plusmn;\u0026thinsp;15.08\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.27\u0026thinsp;\u0026plusmn;\u0026thinsp;0.46\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.35\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eE\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;4 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e139.22\u0026thinsp;\u0026plusmn;\u0026thinsp;12.83\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.51\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.33\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eF\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;6 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e128.63\u0026thinsp;\u0026plusmn;\u0026thinsp;9.52\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.85\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.01\u003csup\u003eac\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eG\u003c/b\u003e QA\u0026thinsp;+\u0026thinsp;10 \u0026micro;M TA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e194.11\u0026thinsp;\u0026plusmn;\u0026thinsp;24.37\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39\u003csup\u003ed\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.33\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.02\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"5\"\u003eData are shown as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) of three separate tests. At p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, means with distinct superscripts exhibit a significant difference. SOD\u0026thinsp;=\u0026thinsp;superoxide dismutase (nmol/min/mg protein); CAT\u0026thinsp;=\u0026thinsp;catalase (\u0026micro;mole/mg protein/min); GST\u0026thinsp;=\u0026thinsp;glutathione \u003cem\u003eS-\u003c/em\u003etransferase (\u0026micro;mole/mg protein/min); GPx\u0026thinsp;=\u0026thinsp;glutathione peroxidase (\u0026micro;mole/mg protein/min)\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTannic acid (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), one of the many naturally occurring antioxidants, has been shown to have a variety of biological effects, such as antiviral, antibacterial, anti-inflammatory, antiallergic, antithrombotic, and vasodilatory properties\u003csup\u003e\u003cb\u003e27\u003c/b\u003e\u003c/sup\u003e. Antioxidant activity is a basic characteristic essential to life, and it can lead to the development of antiaging, anticarcinogenic, and antimutagenic properties, among others\u003csup\u003e\u003cb\u003e28\u003c/b\u003e\u003c/sup\u003e. Tannic acid and other phenolic compounds have antioxidant action primarily because of their redox characteristics, which enable them to function as hydrogen donors, reducing agents, and singlet oxygen quenchers. Furthermore, they might have the ability to chelate metals\u003csup\u003e\u003cb\u003e29,30\u003c/b\u003e\u003c/sup\u003e. This research is necessary to uncover the mechanisms by which tannic ameliorates neurodysfuction, by investigating it effect on cerebral and spinal antioxidant indices and sodium pump activities of rat cerebral and spinal tissues.\u003c/p\u003e\u003cp\u003eOne of the components of DNA, deoxyribose, is released as cells die and their DNA breaks down\u003csup\u003e\u003cb\u003e31\u0026ndash;33\u003c/b\u003e\u003c/sup\u003e. Interaction with ROS can cause a wide range of oxidative modifications to DNA, such as damages to the deoxyribose moiety of the DNA double helix's sugar-phosphate backbone, nucleobase modifications within the sequence, single- and double-strand breaks and DNA-protein crosslinks\u003csup\u003e\u003cb\u003e34\u003c/b\u003e\u003c/sup\u003e. During normal metabolic circumstances, these kinds of oxidative damage to DNA are typically repaired by the cells; but, during oxidative stress, the volume of DNA lesions exceeds the capacity of the repair process, leaving some DNA lesions unrepaired.\u003c/p\u003e\u003cp\u003eThese unrepaired DNA lesions have the potential to cause oxidative stress-related etiologies, such as neurodegenerative disorders. One metabolite of the kynurenine pathway that has been linked to the pathophysiology of neurodegenerative illnesses is quinolinic acid, which may be a neurotoxin. Concerns regarding its potential to contribute to neuronal injury are raised by its capacity to cause oxidative stress in neural tissues\u003csup\u003e\u003cb\u003e17,18\u003c/b\u003e\u003c/sup\u003e. The mechanism of Quinolinic acid-induced damage is mediated by overactivation of glutamate receptors, as QUIN is a selective NMDA subtype of glutamate receptor agonist\u003csup\u003e\u003cb\u003e35\u003c/b\u003e\u003c/sup\u003e. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e illustrates a significant (\u003cem\u003ep\u003c/em\u003e ˂0.05) increase in degradation of deoxyribose after quinolinic acid treatment of deoxyribose sugar. Therefore, quinolinic acid could cause the degradation of deoxyribose constituents of nucleic acid present in the brain and spinal tissue homogenates. However, treatment with tannic acid significantly inhibited (\u003cem\u003ep\u003c/em\u003e ˂0.05) the degradation of deoxyribose by QA. Hence, tannic acid could exhibit potent inhibitory actions against degradation of deoxyribose components of the nucleic acid in the rat brain and spinal tissue homogenates and this result is in tandem with the one demonstrated by Kade et al.\u003csup\u003e\u003cb\u003e15\u003c/b\u003e\u003c/sup\u003e, that tannic acid inhibited degradation of the deoxyribose by ferrous sulphate (FeSO\u003csub\u003e4\u003c/sub\u003e).\u003c/p\u003e\u003cp\u003eOne of the main mechanisms of CNS injury caused by free radicals is lipid peroxidation, which directly destroys neuronal membranes and produces a variety of downstream products that cause significant cellular damage. Highly reactive electrophilic aldehydes, such as malondialdehyde (MDA), 4-hydroxy-2-nonenal (HNE), the most prevalent product, and acrolein, the most reactive, are formed when free radicals attack polyunsaturated fatty acids (PUFAs) \u003csup\u003e\u003cb\u003e36\u0026ndash;38\u003c/b\u003e\u003c/sup\u003e. As displayed in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, quinolinic acid evoked a marked production of lipid peroxidation adducts (\u003cem\u003ep\u003c/em\u003e ˂0.05) in both brain and spinal tissue homogenates. Increased membrane stiffness decreased activity of membrane-bound enzymes (such as the sodium pump), damage to membrane receptors, and changed permeability are all consequences of peroxidation of membrane lipids\u003csup\u003e\u003cb\u003e39,40\u003c/b\u003e\u003c/sup\u003e. Apart from causing harm to phospholipids, radicals can target membrane proteins directly and create crosslinks between proteins and lipids, which are linked to modifications in the integrity of the membrane. It is plausible to speculate that disruption of all the aforementioned functions exhibited by PUFAs and their metabolites, in conjunction with protein modification, impact neuronal homeostasis and thus contribute to brain and neuronal dysfunction. However, treatment with tannic acid exerted an inhibitory effect on the cerebral and spinal lipid peroxidation.\u003c/p\u003e\u003cp\u003eResearchers have shown that the primary components with antioxidant and antiradical qualities are flavonoids and flavones, which include polyphenols like tannic acids\u003csup\u003e\u003cb\u003e41\u003c/b\u003e\u003c/sup\u003e, which may be useful in the treatment of chronic diseases whose origin is connected to oxidative stress. This agrees with the findings of Azimullah et al. \u003csup\u003e\u003cb\u003e42\u003c/b\u003e\u003c/sup\u003e that tannic acid mitigated ROS and MDA induced by rotenone. In many organisms including animals, glutathione (GSH) functions as an antioxidant. Important cellular constituents can be shielded from harm by glutathione from sources such heavy metals, peroxides, free radicals, and reactive oxygen species\u003csup\u003e\u003cb\u003e43\u003c/b\u003e\u003c/sup\u003e. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, the delivery of QA to rat brain and spinal tissue homogenates resulted in a significant reduction (\u003cem\u003ep\u003c/em\u003e ˂0.05) in GSH levels. However, treatment with tannic acid markedly increased (\u003cem\u003ep\u003c/em\u003e ˂0.05) GSH levels. This suggests that by raising their level in the central nervous system, tannic acid may modulate the cellular antioxidant system in counteracting the oxidative attack elicited by QA. This also aligns with the work of Azimullah et al.\u003csup\u003e\u003cb\u003e42\u003c/b\u003e\u003c/sup\u003e that tannic acid abolished the depletion of GSH induced by rotenone.\u003c/p\u003e\u003cp\u003eMoreover, animal cells\u0026rsquo; plasma membranes are maintained by the sodium pump, an enzyme that is membrane bound. The ability to adjust to shifting physiological and cellular stimuli depends on this enzyme\u003csup\u003e\u003cb\u003e44\u003c/b\u003e\u003c/sup\u003e. This protein is highly produced by neurons and is responsible for maintaining the electrical potential required for the excitability of this tissue by using between 30 and 60% of the brain\u0026rsquo;s ATP reserve. Quinolinic acid profoundly inhibited the action of Na\u003csup\u003e+\u003c/sup\u003e/ k\u003csup\u003e+\u003c/sup\u003e-ATPase in the homogenate of the brain and spine, as Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e illustrates. Conversely, treatment with tannic acid restored the activity of the enzyme at high concentrations. This result correlates with the one demonstrated by Kade et al.\u003csup\u003e\u003cb\u003e45\u003c/b\u003e\u003c/sup\u003e, that tannic acid could profoundly restore (\u003cem\u003ep\u003c/em\u003e ˂0.05) the activity of Na\u003csup\u003e+\u003c/sup\u003e/ K\u003csup\u003e+\u003c/sup\u003e-ATPase in the cerebral tissue homogenate following reduction of its activity by streptozotocin. Thus, this suggest that tannic acid could have some pharmacological effects on the central nervous system.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eA collection of antioxidant enzymes that can prevent oxidative damage brought on by pro-oxidants make up the antioxidant pool. SOD, CAT, GST, and GPx are some of these enzymes. First line of defense against injury mediated by reactive oxygen species (ROS) is formed by SOD\u003csup\u003e\u003cb\u003e46\u003c/b\u003e\u003c/sup\u003e. These proteins lower the level of superoxide anion free radical (O\u003csub\u003e2\u003c/sub\u003e), which damages cells at high concentrations, by catalyzing its dismutation into molecular oxygen and hydrogen peroxide (H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e). The GPx are a type of antioxidant enzymes that are related to heme-free thiol peroxidases, just like peroxidases. They help to reduce the toxicity of H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e and organic hydroperoxides by catalyzing their reduction to water or matching alcohols\u003csup\u003e\u003cb\u003e47\u003c/b\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eSimilarly, one of the most significant antioxidant enzymes is catalase. Almost all aerobic organisms include it. In a two-step procedure, catalase converts two molecules of hydrogen peroxide into one molecule of oxygen\u003csup\u003e\u003cb\u003e48\u003c/b\u003e\u003c/sup\u003e and two molecules of water\u003csup\u003e\u003cb\u003e49\u003c/b\u003e\u003c/sup\u003e. A family of multifunctional enzymes known as the GSTs is responsible for the well-established detoxification of electrophilic metabolites and xenobiotics\u003csup\u003e\u003cb\u003e50\u0026ndash;52\u003c/b\u003e\u003c/sup\u003e. The conjugation of a broad range of structurally different molecules with electrophilic carbon, nitrogen, or sulfur atoms to GSH is generally catalyzed by GSTs. This study further investigated how tannic acid could restore enzymatic antioxidants in the brain and spinal tissue homogenates after quinolinic acid had reduced their activity. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows that QA administration profoundly impaired (\u003cem\u003ep\u003c/em\u003e ˂0.05) the activity of SOD in the cerebral tissue homogenate. Nevertheless, tannic acid treatment resulted in a significant (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) rise in the activity of the enzyme. Fridovich et al.\u003csup\u003e\u003cb\u003e53\u003c/b\u003e\u003c/sup\u003e indicate that this response implies tannin may mitigate total oxidative stress by successfully restoring cellular defenses against superoxide radicals. Furthermore, quinolinic acid administration caused a significant drop (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in CAT activity in the brain tissue homogenate.\u003c/p\u003e\u003cp\u003eOn the other hand, catalase activity is significantly increased (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;~\u0026thinsp;0.05) upon tannic acid treatment. According to Kade et al. 2013\u003csup\u003e\u003cb\u003e45\u003c/b\u003e\u003c/sup\u003e, this points to a possible mechanism by which tannic acid supports hydrogen peroxide detoxification by protecting cells from oxidative damage. Furthermore, in cerebral tissue homogenate, tannic acid demonstrated a considerable (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) ability to restore GPx activity following its depletion caused by quinolinic acid. This suggests that tannic acid can help the body's defense mechanism against free radicals by encouraging the breakdown of lipid and other organic peroxides. Moreover, quinolinic acid significantly (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) reduced the cerebral tissue homogenate\u0026rsquo;s GST level. Tannic acid administration, however, demonstrated a profound (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) rise in GST activity. In similar manner, as displayed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, QA markedly diminished (\u003cem\u003ep ˂\u003c/em\u003e0.05) the activities of CAT, SOD, GST and GPx in the spinal tissue homogenate and this effect is significant (\u003cem\u003ep\u003c/em\u003e ˂0.05) when compared to the control. Nonetheless, tannic acid substantially abolished (\u003cem\u003ep\u003c/em\u003e ˂0.05) the detrimental effect of QA by evoking a marked increase (\u003cem\u003ep\u003c/em\u003e ˂0.05) in the activities of the spinal antioxidant enzymes. This reveals that tannic acid increases oxidative stress in order to support the antioxidant pool within cells by augmenting the efficacy of the antioxidant enzymes. Findings herein are similar to those of Azimullah et al. \u003csup\u003e\u003cb\u003e42\u003c/b\u003e\u003c/sup\u003e that demonstrated that tannic acid mitigated the depletion antioxidants, SOD, CAT, and GSH, accompanied with profound MDA and NO.\u003c/p\u003e\u003cp\u003eTA has quite a number of mechanisms by which it operates. It has a strong capacity to scavenge free radicals due to its polyhydroxy structure, which donates hydrogen atoms to neutralize ROS. In addition, TA chelates transition metals such as iron and zinc, which catalyze ROS formation via Fenton reactions\u003csup\u003e\u003cb\u003e54\u003c/b\u003e\u003c/sup\u003e. Moreso, TA treatment was observed to reduce lipid peroxidation, prevent loss of endogenous antioxidants, and inhibit the release and synthesis of proinflammatory cytokines, in addition to the favorable modulation of apoptosis and autophagic pathways. TA also attenuated the activation of microglia and astrocytes along with preservation of dopaminergic neurons following reduced loss of dopaminergic neurodegeneration and inhibition of synaptic loss and α-Glutamate cytotoxicity\u003csup\u003e\u003cb\u003e42\u003c/b\u003e\u003c/sup\u003e. Apparently, it is worth mentioning that tannic acid has the efficacy to counteract oxidative damage and ameliorate or restore sodium pump activity in neurological conditions.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe results here in revealed that tannic counteracted the detrimental effects of QA in rat cerebral and spinal tissue homogenates by restoring sodium potassium pump activity and modulating antioxidant indices. Consequently, it is rational to conclude that tannic acid could mitigate oxidative stress processes, redox and homoeostatic complication that characterize neurological diseases. Tannic acid could be considered for the treatment and management of neurodegenerative diseases due to its observed antioxidant and pharmacological activity. However, further investigation is required to determine the translational efficacy of tannic acid into clinical settings.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003ch2\u003eEthical statement\u003c/h2\u003e\u003cp\u003eThis study was carried out accordance to standard guideline of the Committee on Care and Use of Experimental Animal Resources of Faculty of Pure and Applied Sciences and approved by Federal University Wukari, Nigeria with the approval number FUW/FPAS/23/021 and the study is reported in accordance with ARRIVE guidelines.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eE.M conceptualized and designed the research. R.N supervised, Data collection were performed by V.I. , O.E reviewed the work. S.O. carried out data analysis and material preparation. Visualization and resources procurement was carried out by M.A., R.Y. and D.M carried out project administration, while E.M. also wrote the first draft of the manuscript. All authors commented on previous versions of the manuscript. All authors have read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe would like to express our sincere gratitude to all authors for their invaluable contributions to this manuscript. Their expertise, dedication and collaborative spirit greatly enriched the quality of this work. The research is borne out of authors\u0026rsquo; financial contribution as there was no funding from any agency.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets used and analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003e\u003cspan\u003eCunha-Oliveira T, Rego, AC, Oliveira CR (2008) Cellular and molecular mechanisms involved in the neurotoxicity of opioid and psychostimulant drugs. \u003cem\u003eBrain Res. Rev\u003c/em\u003e. 58 (1): 192\u0026ndash;208. https://doi.org/10.1016/j.brainresrev.2008.03.002\u003c/span\u003e\u003c/li\u003e\n \u003cli\u003e\u003cspan\u003eKeifer MC, Firestone J (2007) Neurotoxicity of Pesticides. \u003cem\u003eJ. 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Tannic acid confers neuroprotection via Zn\u0026sup2;⁺ chelation in an ischemic stroke model. \u003cem\u003eInternational Journal of Molecular Sciences\u003c/em\u003e, 23(18), 10823. https://doi.org/10.3390/ijms231810823\u003c/span\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Antioxidants enzymes, Neurodysfunction, lipid peroxidation, Na+/K+-ATPase, Polyphenols, thiols","lastPublishedDoi":"10.21203/rs.3.rs-6990411/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6990411/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe pathophysiology of neurodegenerative illnesses is largely dependent on oxidative stress and poor ion homeostasis, and these conditions represent a substantial worldwide health burden. Endogenous neurotoxic quinolinic acid (QA) is linked to neurodysfunction by inducing oxidative stress and interfering with sodium pump function. In a number of models, the polyphenolic molecule tannic acid (TA), which has strong antioxidant qualities, has demonstrated pharmacological effects in several diseased conditions. However, the neuroprotective effect of tannic acid is rather speculative and still very open for clarification. In the present study, an \u003cem\u003ein vitro\u003c/em\u003e model was employed to examine the effect of tannic acid on deoxyribose degradation, lipid peroxidation, thiol status, antioxidant enzymes, and cerebral and spinal sodium pump in rat cerebral and spinal tissue homogenates treated with quinolinic acid (2 mM). Results revealed that quinolinic acid treatment led to a profound (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) degradation of deoxyribose, formation of thiobarbituric acid reactive substances, and marked reduction (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) in tissue level of free thiols. However, tannic acid treatment significantly (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) counteracted thiobarbituric acid reactive substances production, deoxyribose degradation and markedly increased (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) the thiol level of the cerebral and spinal tissue homogenates. Furthermore, quinolinic acid markedly (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05) diminished the activities of cerebral and spinal antioxidant enzymes, such as catalase, superoxide dismutase, glutathione peroxidase, and glutathione \u003cem\u003eS\u003c/em\u003e-transferase, and impaired the activities of cerebral and spinal sodium pump. Nonetheless, the activities of the antioxidant enzymes and pump were all raised in both the cerebral and spinal tissue homogenates upon tannic acid treatment. These findings justify the pharmacological action of tannic acid on quinolinic acid-induced neurotoxicity and suggest its potential use in the treatment of neurodegenerative diseases.\u003c/p\u003e","manuscriptTitle":"Tannic Acid Attenuates Quinolinic Acid-Induced Neurodysfunction by Modulating Oxidative Stress and Pump Activity In vitro","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-09 12:25:21","doi":"10.21203/rs.3.rs-6990411/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"500dd934-f721-47b7-b7c0-3f2b06192d10","owner":[],"postedDate":"July 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":51101645,"name":"Biological sciences/Biochemistry"},{"id":51101646,"name":"Biological sciences/Drug discovery"},{"id":51101647,"name":"Health sciences/Neurology"},{"id":51101648,"name":"Biological sciences/Neuroscience"}],"tags":[],"updatedAt":"2025-11-27T07:24:13+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-09 12:25:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6990411","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6990411","identity":"rs-6990411","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}