Daidzein from Dietary Supplement to a Drug Candidate: An Evaluation of Potential.

Daidzein has been analyzed using different analytical methods, such as high-performance liquid chromatography (HPLC), Raman spectroscopy, FTIR spectroscopy, and polarimetry. 14 Daidzein and genistein analysis requires a more effective, precise, and easy procedure in the preparation of a soybean sample. Gradient elution systems have been utilized extensively in research; however, the isocratic method can improve this approach. 15 , 16 Some of the methods are briefly described in Table 3 . As daidzein falls under Biopharmaceutics Classification System (BSC) class IV compounds, it is extremely clear that it has low solubility and penetrability, particularly through skin, which prevents the medicine from expressing its full therapeutic potential. 21 To make the use of daidzein easier, scientists have developed many dosage forms, such as gels, complex formations, polymer formations, cocrystallization, etc. In a study by Qiu et al., it was discovered that daidzein preparations in solutions are more stable than those in solids. 22 Since phenolic groups are naturally weakly acidic, they make it challenging to combine bases and salt at physiological pH. 23 This can be avoided by forming hydrogen bonds with complementary groups, such as those found in daidzein, during the cocrystallization process, which will increase solubility. The solution to entering the skin and treating conditions that resemble melanoma is to use nanobased gels. 24 Additionally, efforts have been made to create daidzein-loaded poly(lactide- co -glycolide) nanoparticles utilizing structural and crystal engineering to increase its solubility and stability, 25 particularly when taken orally. Theophylline and cyclodextrin have also been used to make a number of complexes compatible with daidzein, 21 improving solubility, but these methods restrict the use of daidzein to food and functional products as they require large amounts of reagents and are labor-intensive to carry out. 25 The natural substance daidzein, which is present in some plants, especially soybeans, may cause a variety of adverse reactions, including bloating, colitis, constipation, diarrhea, sleeplessness, itching, nausea, skin rash, and changed thyroid hormone levels. Bloating, a sensation of fullness and discomfort in the abdomen, can occur in some people, while colitis, an inflammation of the colon that can result in diarrhea and abdominal pain, can happen to other people. In addition to diarrhea and constipation, irregular bowel movements might also happen. Another negative effect is insomnia, which is the inability to fall or stay asleep. Aside from skin rash and nausea, some people who consume daidzein may also feel itching and itchiness. Daidzein has also been linked to altered thyroid hormone levels. 26

The pharmacological benefits and other useful characteristics of DDZ have captivated scientists across the globe to conduct exhaustive research and studies, and in doing so they were successful in establishing numerous intellectual property rights in the shape of patents for several ailments like osteoporosis, skin treatment, etc. Table 6 outlines the information about some of the patents with their application numbers and invention details in various countries, with China having the most patents on DDZ.

Red clover ( Trifolium pratense ), soybean ( Glycine max ), lucerne ( Medicago sativa ), kudzu ( Pueraria radix ), and red lentils ( Lens esculenta ) and other legumes (Leguminosae) are among the plants that contain DDZ primarily in the form of glucosides (as depicted in Figure 3 ). The most plentiful sources of DDZ among them are thought to be soybeans and products made from soybeans. 10 The amount of total isoflavones in soybean varies based on the variety of soybean, the geographical distribution, and the harvesting year. Owing to fermentation’s active increase in the concentration of aglycones, the quantity range of DDZ in the soured soybean type is larger than that in nonfermented soybeans. 11 Biological sources of DDZ which include red clover ( Trifolium pratense ), soybean ( Glycine max ), lucerne ( Medicago sativa ), kudzu ( Pueraria radix ), and red lentils ( Lens esculenta ). It has been shown that several microorganisms, including Bacillus species, Rhizopus species, and Aspergillus species, participate in the fermentation process by a glycosylating isoflavone. Another well-known traditional Chinese medicine that is frequently taken as dietary supplements is kudzu root ( Pueraria radix ), which has been found to contain DDZ in both its glycoside and aglycone forms. 12 Various plant species have varied amounts of daidzein, expressed in milligrams per kilogram of dry weight. The amount of daidzein in Glycine max , also referred to as soybeans, is relatively high at 37.6 mg/kg ( Table 1 ). Garden peas, or Pisum sativum , have 0.4 mg/kg daidzein, which is a lesser concentration. Common beans, or Phaseolus vulgaris , have a moderate 23.2 mg/kg daidzein concentration. Lima beans ( Phaseolus lunatus ) and mung beans ( Vigna radiata ) have a lower daidzein concentration of 0.3 mg/kg. Adzuki beans, or Vigna angulariz , and fava beans, or Vicia faba , contain 4.6 and 5.0 mg/kg daidzein, respectively. 13

DDZ has been studied clinically in different countries for various ailments such as hypertension, postmenopausal symptoms, type 2 diabetes, prostate cancer, etc. Some of the trials are approved or completed while others are pending. The investigation of the impact of phytoestrogens on serum lipids in postmenopausal women is one such study in Serbia. In the United States, a phase 3 trial of soy isoflavones with menopausal hot flashes is completed. In China, a trial was conducted and completed on a sample size of 400 that attempted to know the effects of DDZ on serum lipid profiles in hypercholesterolemia patients with different equol metabolism phenotypes. In the neurological disorder segment, research at the University of Wisconsin—Madison in the United States was successful in determining the potential benefits DDZ imparts for therapy of Alzheimer’s disease. A combinatorial examination was performed and concluded in New Zealand to unleash the effect of soy isoflavones with different green kiwifruit on hormonal levels, bone turnover, and fecal microflora in menopausal women. An analysis to study the impact of soy isoflavone on endothelial function and its ability to lower oxidative stress was carried out and finished in Indonesia for a sample size of 200. Various documented clinical trials to date have been listed in Table 5 .

DDZ is present in significant quantities in a variety of dietary supplements, bodybuilding drinks, sports drinks, newborn formulas, etc. Therefore, there are different types of products by manufacturers that are available in the global market. Most of the products are solid like capsules and tablets. The quantity of DDZ varies in different product units with the most recommended daily dose of one to two capsules. The data of various commercial products listed in Table 7 have been collected from the Dietary Supplement Label Database (DSLD; https://dsld.od.nih.gov/ ). These products are available in capsule and tablet form, and the majority of these supplement/botanicals/nutraceutical product are manufactured in the United States.

Recent years have seen a significant increase in the amount of research done on DDZ. In this review, the pharmacological characteristics of DDZ have been noted. Its outcomes include anticancer, anticardiovascular illnesses, antiosteoporosis, antidiabetes, anti-inflammation, antioxidant, antiaging, neuroprotective, and other effects. From many past years, traditional hormone replacement therapy has been utilized clinically to improve menopause symptoms; however, problems such as mammary cancer have restricted its use in therapeutic settings. It was established that DDZ has a structure identical to that of estrogen and is sensitive for the estrogen receptor. It is currently being utilized extensively for treatment of a variety of ailments, and there is optimism regarding the expansion of its therapeutic applications in the near future. The mechanisms of action are still not completely known, and its poor bioavailability considerably restricts the applications for which it can be used. Additionally, there have been reports of DDZ possibly causing certain unwanted side effects. Therefore, it is essential to further explain the mechanisms at play, in order to lessen the adverse effects associated with its usage. Some biotransformation or synthetic analogues of DDZ, such as isoformonetin and 7,3′,4-THIF, may be more beneficial to health and/or less hazardous. Although certain bioactive analogues of DDZ with beneficial effects on human health have been discovered, many more possible metabolites remain unknown. Therefore, it is vital to discover new beneficial chemicals based on the DDZ structure. Furthermore, it is of the utmost importance to improve the absorption and bioavailability of DDZ. This may be accomplished either by modifying the drug in accordance with its physicochemical features and pharmacokinetic factors or by selecting the most appropriate route of administration. Therefore, additional research must be conducted on DDZ before it may be extensively advocated for its therapeutic usage.

The biosynthesis pathway of DDZ is a seven-step enzyme mediated and irreversible chain of reactions as depicted in Figure 4 . It starts with the precursor l -phenylalanine, which on going through nonoxidative deamination via the enzyme phenylalanine ammonia lyase, converted to cinnamic acid The next step is the conversion of cinnamic acid to p -coumarate, which is accomplished by the action of the enzyme cinnamic acid 4-hydrolase (C4H). The third step involves the transformation by the enzyme 4-coumarate:CoA ligase ( p -coumaroyl-CoA; 4CL). A seven-step biosynthesis pathway of DDZ which starts in the presence of phenylalanine as it acts as a precursor. DDZ is formed from liquiritigenin in the presence of glucosyl transferase. The formation of chalcone in the next step is aided by the enzyme chalcone synthase (CHS), which on reduction by chalcone reductase (CHR) generates isoliquiritigenin. The penultimate step is the isomerization of isoliquiritigenin to liquiritigenin with the help of the enzyme chalcone isomerase (CHI). The concluding step is the formation of DDZ, which involves the transfer of the glucosyl group and is accompanied by the enzyme glucosyl transferase (GT). 14

In recent times, natural remedies have been considered as an important kind of approach for cures. Historically, medicinal plants have been utilized to both treat and stave off various illnesses. Natural products have been used for the treatment of different ailments since prehistoric times. According to a fossil study, the first or oldest evidence of the usage of plants as medicines dates back about 60 000 years. 1 This offers a fresh perspective on how the knowledge of traditional medicinal plants is operating and how it might be applied to treat emerging and lifestyle disorders. However, there is growing support for incorporating traditional herbal medicine knowledge into the investigation of new therapeutic agents. Various computational methods for bioprospecting in the postgenomic era can be used to investigate the rich medicinal plant history. 2 While many new medications have been created over the past 50 years utilizing high-throughput screening techniques and combinatorial chemistry, natural products and the chemicals produced from them have remained crucial elements in pharmacopoeias. Only a small number of the estimated 250 000–500 000 plant species currently in existence have been studied scientifically for bioactivities. 3 Therefore, there is a lot of potential for new scientific discoveries to come from plants and other natural products, which may be used to learn a lot about unique chemical structures and their innovative modes of action in the context of developing new drugs. 4 The three main factors driving this trend away from synthetic contemporary pharmaceuticals and toward a wider usage of nutraceuticals are (1) cost effectiveness, (2) safety, and (3) accessibility. 5 Phytoestrogens are phenolic plant compounds that are nonsteroidal and naturally occur and, by virtue of their size and molecular makeup, mirror the steroid estrogens produced by vertebrates. They fall into two categories: flavonoids and nonflavonoids. Isoflavones, coumestans, and prenylflavonoids are examples of flavonoids, whereas lignans are examples of nonflavonoids. 6 Isoflavone phytoestrogens include genistein, daidzein (DDZ), glycitein, biochanin A, and formononetin. Humans primarily obtain isoflavones through their diets from soy and soy products, which are primarily composed of DDZ and genistein. They have estrogenic and/or antiestrogenic effects when ingested. Red clover’s methoxylated isoflavone formononetin is successfully transformed into DDZ in the human gastrointestinal tract; it serves as an indirect source of DDZ. Red clover extract based phytoestrogen dietary supplements are becoming more and more well-liked as an alternative therapy for the management of menopausal symptoms. Isoflavones are thought to be chemoprotective and can be used as an alternative therapy for a variety of hormonal illnesses, including menopausal symptoms, cardiovascular diseases, osteoporosis, and numerous cancer types, including breast and prostate cancers. 7 DDZ (a phytoestrogen that belongs to the category of nonsteroidal estrogens), a nutraceutical ingredient so far, belongs to chemical class of isoflavones. It is a multitargeted herbal moiety that is used to address the challenges of a number of ailments, including osteoporosis, cancer, and inflammation, with antihemolytic, antioxidant, and anti-inflammatory effects. It has also protective properties against some illnesses like diseases of the cardiovascular system, diabetes, osteoporosis, and malignancy of the breast; these are connected by which estrogen control is regulated. Other biological functions not related to the ER (estrogen receptor) include safeguarding the skin and nerves, anti-inflammatory effect, anticancer function, and inhibition of oxidative damage. These positive outcomes are mostly attributable to immunological reaction modulation, oxygen free radical scavenging, proliferation inhibition, and other factors. 8 DDZ has a chemical structure (as shown in Figure 1 ) similar to that of mammalian estrogens and acts in two directions by either replacing or influencing the ER complex, estrogen receptor, and the hormone estrogen. It can be found in foods produced from soy, such as textured soy protein, soy flour, and soy protein isolates, as well as tofu, tempeh, and miso. Additionally, in supplementary flours made from wheat, rice and maize are fortified with soy flour. 9 Daidzein chemical structure. This review article is an attempt to bring DDZ to the forefront through the study of how its pharmacological properties have been used to treat a variety of ailments and how it has been incorporated into health supplements. The global market capitalization of DDZ reflects its importance as a multitargeted drug with numerous patents and clinical trials. The enhancement of characteristics like quality, dependability, end-user requests, and applications has led to a significant segmentation of the DDZ market. The DDZ market research includes general success criteria, restrictions, and in-depth illumination of significant information on recent and upcoming examples that may affect development. In-depth analysis of current advancements, factors, and establishments is provided in the DDZ market research. North America, Europe, the Middle East, Africa, Southeast Asia, and South America are among the major geographical areas that were examined. Figure 2 reveals that, according to the output capacity, utilization percentage, market base, supply and demand situation, profit income margin, and other factors, the top players in the DDZ market are projected to have a global presence. Market surveillance of daidzein by region. North America has the highest proportion (35%), followed by Asia Pacific, Europe, and the Middle East; the lowest contribution (5%) is by Africa. https://www.datalabforecast.com/industry-report/386257-daidzein-market/ .

DDZ is mostly present in soy and many unfermented foods, where it can also be found in the forms of acetyl glycoside and aglycone. The glycoside conjugate 27 of DDZ must first, by glucosidases in the small intestine, be converted into the aglycone form in order to be absorbed in the gut. Human gut bacteria either absorb or break down the aglycone form into a variety of metabolites, such as dihydrodaidzein, equol, and O -desmethylangolensin ( O -DMA; a metabolite with no or little estrogenic activity). The structures of these metabolites are shown in Figure 5 . Studies on DDZ distribution, bioavailability, absorption, and excretion, however, are still few; there are a number of procedures, including reduction, methylation, and demethylation. There are two processes: hydroxylation and C-ring cleavage that are involved in this intestinal biotransformation. 28 DDZ is a physiologically inert component of plants that is present in the form of glycosides (also known as DDZ) and is unaltered during various food preparation processes. Three metabolites of DDZ. Equol is formed in the intestine, O -desmethylangolensin is formed in the colon, and an intermediate product, dihyrodaidzein, is formed in the intestine. The bioconversion of DDZ involves the gut bacteria in a significant way. Following ingestion, the small intestine’s lactase enzymes, certain strains of Bifidobacterium and Lactobacillus , hydrolyze the glycosidic bond of DDZ. This results in the synthesis of the bioactive aglycone moiety, DDZ. Following glycosylation, a number of bacterial varieties prevalent in the gut of human proceed to demethylate and reduce DDZ to produce its variations. 29 According to certain reports, DDZ is hydrogenated into dihydrodaidzein (DHD) by the microorganisms Clostridium sp. TM-40 and Coprobacillus sp. MRG1. Using a two-step process and the reductive cleavage of a heterocyclic ring, DHD can be further metabolized to produce DMA and equol. 30 Colonic bacteria further metabolize DDZ to create equol or O -desmethylangolensin through a process that produces the intermediate dihydrodaidzein. Equol is an estrogen that is not a steroid and that is only produced in the intestine by bacteria that are metabolizing the soy isoflavone DDZ. These metabolites can then move to the liver for further metabolization. Finally, bacterial enzymes in the colon deconjugate both the DDZ and biliary byproducts that are not absorbed before they are either reabsorbed or metabolized. 31 The small intestine is the site where DDZ is absorbed, as evidenced by the emergence of a modest peak in plasma roughly 1 h after consumption. 32 After 5–8 h, a bigger peak results from the colon’s absorption and recycling of the conjugates. It is interesting to note that most DDZ in plasma is found conjugated, with a very tiny amount in aglycone form. 33 A clinical investigation revealed that eating DDZ in the glucoside form leads to higher bioavailability than doing so in the aglycone form, in contrast to earlier research that had revealed the opposite. The effect of additional isoflavones on their metabolic process may be responsible for these contentious outcomes. Despite these investigations, it seems that DDZ reaches the peak plasma concentration 7 h after it is ingested, which is thought to be related to the absorption process. A study revealed that practically all DDZ is quickly absorbed and digested because there is little excretion in stools or urine; however, up to 30% of DDZ intake can be retrieved in urine. 34 During a 24 h incubation, it has been demonstrated that a mouse colon derived anaerobic bacterium (Mt1B8) converts roughly 80% of DDZ to equol. The upper small intestine uses passive diffusion to absorb the aglycone molecule from the digestive tract. When compared to persons who consume nonfermented soybean, people who eat fermented soy products may absorb isoflavones more readily. This may be because fermented foods have probiotic benefits that may increase the population of gut bacteria. 35 When soy milk containing glucoside conjugates is ingested, DDZ absorption is significantly 2 h faster than when solid soy meals are consumed. Another study discovered that insoluble fiber, including inulin, may boost the absorption of DDZ in part by stimulating bacterial growth. Studying the possible advantages of DDZ, however, requires taking into account a crucial component of its metabolism. The correlation between plasma levels and poor concentration prevents the various tissues from really receiving it. In fact, how much isoflavones and their derivatives are present in human tissues is not always known and can vary greatly. 31 For instance, equol levels in human glandular tissue range from 456 to 559 nmol/kg and those in breast adipose tissue range from 22 to 36 nmol/kg. 36 Human serum proteins can be nonspecifically bound by DDZ. It has been found to be present in plasma in a very low concentration which accounts for only 12%. It has been proposed that only the unbound fraction, which is free to interact with the target receptor, may be capable of producing biological effects that are particular to the target. 37 DDZ is also thought to be present in a variety of tissues, including the placenta, kidney, liver, muscle, and mammary gland. In the brain, within the first hour of dosing, a discernible concentration of DDZ was discovered. Finally, DDZ absorption, bioavailability, and metabolism may be influenced by a number of variables, including age, dietary habits, and the gut bacterial community. 38

Consuming isoflavones may boost one’s health and minimize the symptoms of menopause as well as the risk of a number of age-related illnesses, including heart disease, fragile bone condition, and cancers. 39 Supplementing with DDZ has been shown to have significant impacts, to decrease insulin resistance and inflammation, and in changes in lipid profiles within plasma, dyslipidemia, and other issues linked to obesity. 40 , 41 Anti-inflammatory, cardioprotective, neuroprotective, and antiaging actions are further noteworthy effects. The following describes the function of DDZ in the human body and its specific mode of action for various conditions in Table 4 . The pharmacological action of DDZ has been shown in controlling the diseases and ultimately leading to their treatment. Soy’s effect on the development of breast cancer has been extensively studied. According to a meta-analysis, isoflavone supplementation may be beneficial for those with ER-negative breast cancer and may be linked to a lower incidence of the disease. 86 DDZ supplementation is often linked with reduction in relapse of breast cancer in postmenopausal women. A lesser expression of HER2/neu and proliferating cell nuclear antigen (PCNA) in tumors has also been linked to soy consumption (DDZ), which is directly linked to a more proliferative, malignant tumor phenotype. DDZ is essential for controlling breast cancer cells encroaching brought on by tumor necrosis factor (TNF). The molecular foundation of this has been explained by two different signaling routes, one of which is the signaling network of nuclear factor kappa B (NF-κB). DDZ treatment decreased breast cancer cells releasing uPA after TNF-induced NF-B and AP-1 blocked the MDA-MB-231 breast cancer cell line, which prevented the spread of the disease. DDZ blocked the Hh/Gli1 signaling pathway, which prevented TNF from inducing MMP-9 activity and expression. DDZ also inhibits the proliferation of breast cancer cells by causing cell cycle arrest in the G1 and G2/M phases as well as the activation of death. 87 DDZ increased the production of intracellular reactive oxygen species (ROS), which altered the transmembrane potential of the mitochondria and caused the release of cytochrome c . The discharge of cytochrome c was boosted because of the upregulation of the proapoptotic protein Bax and the antiapoptotic protein Bcl-2. These substances eventually caused cell death by increasing caspase-9 and caspase-7 activities. 88 DDZ described antiproliferative properties in three prostate cancer cell lines (LNCaP, DU 145, and PC-3), triggering G0/G1 phase cell cycle halt and inhibiting blood vessel formation via altering the transcription of genes and its expression in the route linked to cyclin-dependent kinase. 89 A few of these genes are involved in the expression of angiogenesis genes and the pathway for sensing DNA damage; when these pathways are inhibited, the growth factors EGF and IGF are decreased, which slows the growth of tumors. Prostate cancer growth is androgen-dependent in LNCaP and prostate cancer cells. A newly discovered gene called prostate androgen-regulated transcript-1 (PART-1) responds to androgens and may be used as a biomarker for prostate cancer. Dihydrotestosterone (DHT)-induced PART-1 expression was dose dependently decreased by DDZ, indicating a potential antiandrogenic effect of DDZ. The relationship between the expansion of prostate tumors and the suppression of PART-1 expression has been the subject of several in vivo studies. DDZ has the ability to induce tumor necrosis factor related apoptosis-inducing ligand (TRAIL) mediated apoptotic death exclusively in tumor cells. 90 The endogenous anticancer drug TRAIL causes LNCaP cells’ mitochondrial membrane potential to be disrupted, which encourages apoptosis. In general, DDZ indicates contributing to both the prevention and treatment of prostate cancer. 91 At different doses, DDZ exhibited a biphasic activity in human colon cancer cells, which is helpful in the treatment of colon cancer. Cell cycle capture in the G0/G1 phase and caspase-3-dependent apoptosis had little effect on differentiation but had tumor-suppressive effects in LoVo cells. DDZ was found to have no effect on healthy human hepatocytes, according to research using liver cancer SK-HEP-1 cells as a cell model. However, liver cancer cell proliferation was found to be inhibited by DDZs. The ability of DDZ to trigger apoptosis was associated with regulation of the Bcl-2 family via the mitochondrial pathway. In several types of murine and human neuroblastoma cell lines, DDZ still exhibits anticancer properties by inhibiting cell growth, stopping the cell cycle in the G2/M phase, and inducing cell death. Although DDZ has no effect on COX-2 expression, its biotransformation makes it a possible chemopreventive agent for skin cancer. 92 By increasing cell apoptosis, the compound DDZ conjugated to N - t -Boc-hexylenediamine (cD-tboc) possesses antibodies against both thyroid and epithelial ovarian carcinomas. In contrast to other isoflavones, DDZ is special in that it may be used to treat osteoporosis. DDZ can also impede the absorption of bone. A study about cultivation of osteoblasts from young female pigs’ long bones showed that DDZ at a modest dose (1 nM) accelerated mineralization, increased ALP activity, and promoted osteoblast growth via the ER route. Additionally, the presence of ER was shown by an increase in the synthesis RANK ligand osteoprotegerin (OPG) which is RANK-L and runx2/Cbfa1, all of which are implicated in osteoclastogenesis. As a result, DDZ is essential for osteoblast development and function. DDZ also prevented osteoclast development and activation primarily by triggering caspase-3 to cause osteoclast progenitor death. 93 Numerous DDZ analogues were shown to have antiosteoporosis effects by encouraging ER for separate development of stromal stem cells obtained from adipose tissue (ASCs) and mesenchymal stem cells (BMSCs) from bone marrow. For instance, the methoxy-DDZ isoformonetin decreased bone loss by preventing osteoblasts from death. 94 One of the most bioactive soy phytoestrogen ingredients, DDZ, has antidiabetic properties. Experiments both in vivo and in vitro have shown that DDZ has antihyperglycemic activity. DDZ increased glucose uptake by encouraging AMPK activation to enhance in a type 2 diabetic cell model; L6 myotubes, muscle cells’ PM, were translocated by glucose transporter 4. (The DDZ effect in the metabolism of glucose is depicted in Figure 6 .) This resulted in glucose homeostasis that was insulin independent. In in vivo studies using db/db and KK-Ay mice as animal models for type 2 diabetes, 95 DDZ was seen to control elevated blood sugar levels to demonstrate its antihyperglycemic action. DDZ has been shown to protect against type 2 diabetes and has the potential to be developed into an effective therapeutic phytochemical for the treatment of diabetes. Proposed molecular basis for daidzein and protective effects against faulty glucose metabolism. DDZ has been seen to control elevated glucose levels in blood to demonstrate its action against hyperglycemia. 96 Type 2 diabetes and DDZ have also been connected by adjusting the related enzyme activity; cholesterol and glucose metabolism in the liver are regulated. DDZ also decreased the increase in postprandial blood sugar levels by preventing glucosidase and amylase from digesting carbohydrates. 97 Treatment with DDZ is often shown to reduce the activation of many mediators of inflammation associated with various diseases such as insulin resistance, type 2 diabetes, and heart related disease. DDZ enhanced PPAR and adiponectin gene expression and adipogenic differentiation while downregulating expression and secretion of the MCP-1 gene. 98 Macrophage cells treated with palmitate and DDZ treatment resulted in a significant increase in PPAR transcriptional activity as well as a reduction in JNK phosphorylation, followed by a decrease in Ccl2 and IL6 mRNA levels. Additionally, DDZ supplementation in the coculture system of adipocytes and macrophages lowered pro-inflammatory cytokine gene expression while increasing adiponectin gene expression through increasing PPAR transcriptional activity. 99 The adipocytes and macrophages cocultured in a system are shown in Figure 7 . Anti-inflammatory activity of DDZ in coculture of adipocytes and macrophages. In adipocytes DDZ causes increased activity of PPARγ and adiponectin gene expression, while in macrophage it causes downregulation of NF κB, JNK, PARP 1 and AP-1, thus decreasing the activity of pro-inflammatory cell and resulting in anti-inflammatory activity. DDZ’s anti-inflammatory properties have also been investigated using murine MLE-12 epithelial cells treated with TNFc. According to the findings, the administration of DDZ dramatically reduced TNF’s ability to promote NF-κB transcriptional activity, Cxcl2 expression and activity, and protein PARylation. Results from experiments with the NF-κB-Luc reporter plasmid and PARP1 expression plasmid revealed DDZ’s anti-inflammatory properties. 100 Soy supplementation (DDZ) in postmenopausal women shows positive results for muscle strength. Studies have shown that supplementation with isoflavones, specifically daidzein, help toward better cognitive health. 9 The capacity of DDZ as a skin barrier, the capacity of DDZ in order to promote penetration through the skin, and the fact that DDZ exhibited nonionized forms, compared to ionized forms, cause higher skin layering. 101 By use of the transdermal route, DDZ absorption was only mildly effective, but repeated transdermal administration of DDZ might increase its concentration in plasma despite the fact that aglycone combination and PEG400 can improve skin penetration. 102 DDZ’s antioxidant activity makes it good for animal health. DDZ reduced a result of lipid peroxidation, which is higher MDA levels, in streptozotocin-induced diabetic rats and boosted the suppressed action of SOD to reduce oxidative stress, including the avoidance of vascular damage. In a dose-dependent way, DDZ exerted its therapeutic effect by returning the regular AOE and AE concentrations. 103 Compared to DDZ alone, certain of its metabolites, O -DMA with equol, for example, demonstrated higher antioxidant capacities in vitro. These compounds did this by enhancing catalase and SOD activity and expression. Two other DDZ metabolites, 3′-OH-DDZ and 6-OH-DDZ, were similarly more efficient than DDZ. 104 DDZ is a potential therapy option for illnesses. It works by primarily controlling the metabolism of lipids in the blood, reducing high blood pressure readings, enhancing the capacity for antioxidants, and attenuating the dysfunction of endothelial cells. Use of DDZ for 6 months dramatically reduced triglyceride levels (TG). 105 Glucose and other lipids were unaffected, although the concentration that is connected to the ESR-RsaI genotype was impacted. Another effect of DDZ was to downregulate an independent CVD risk factor. Additionally, DDZ and its metabolite equol were discovered to significantly reduce hypertension through regulating vascular modulating humoral systems, renal function, and the balance between vasodilators and vasoconstrictors to control smooth muscle tone function, which decreases blood pressure as a result. But DDZ’s ability to lower blood pressure has only been proven in animal models thus far, and human clinical trials are still required to confirm it. 38 , 106

Daidzein with the molecular formula C 15 H 10 O 4 has a melting point of 320 °C and boiling point of 512–513 °C at 760 mmHg. Moreover, its partition coefficient as reported by Vegas Software is 3.16. Additionally, its maximum absorption wavelength is 250 nm. A detailed description of its chemical and physical properties is given in Table 2 ( https://health.ec.europa.eu/system/files/2022-10/sccs_o_263.pdf ). https://health.ec.europa.eu/system/files/2022-10/sccs_o_263.pdf . Calculated by Vega Software.