The effects of adalimumab on the rat autotransplantation endometriosis model: A placebo-controlled randomized study

The authors would like to thank Prof. Dr. Mehmet Şimşek from the Department of Obstetrics and Gynecology, Adiyaman University, Turkey, for his contribution. Received on September 16, 2020 Reviewed on August 26, 2021 Accepted on November 30, 2021 Published online on January 18, 2022

Background. Endometriosis is a ch ronic inflammatory pathology that can cause persistent pelvic pain and infertility by affecting women of reproductive age. It is defined as the placement of endometrial tissue outside the uterine cavity. Hormonal, genetic and immunological factors have an effect on the development of e ndometriotic implants. Adalimumab is a m onoclonal antibody specific for tumor necrosis factor alpha (TNF-α), used in the treatment of autoimmune diseases. Objectives. To in vestigate the e ffectiveness of a dalimumab on hi stopathological and biochemical values in r ats with experimental endometriosis.

and methods. This study is a comparative, prospective, experimental rat study. Wistar albino female rats were divided into 4 groups. Group 1 was separated as the control group. Endometriotic implants were simultaneously induced in group 2 and group 3. After 4 weeks, developing endometriotic foci were measured. Adalimumab (5 m g/kg) was simultaneously intraperitoneally (ip.) administered to g roup 3 and group 4 for 4 weeks. At the end of the study, histopathological scoring and fibrillin-1 scoring were performed. Total antioxidant status (TAS), total oxidant status (TOS) and malondialdehyde (MDA) values were measured. Findings in a ll groups were compared. Results. When group 1 and group 2 were compared, the histopathological score, as well as MDA and TOS levels increased, while TAS levels decreased in group 2 (p < 0.001). After adalimumab treatment, the average endometriotic implant size in group 3 (0.32 ±0.002 mm) decreased compared to group 2 (0.77 ±0.04 mm) (p = 0.032). While fibrillin-1 score increased in group 2 and group 3 compared to group 1, it decreased in group 3 compared to g roup 2 (p < 0. 001). Histopathological score decreased, TAS levels increased and MDA levels decreased in group 3 compared to group 2 (p < 0.001). Conclusions. Adalimumab may play a role in the regression of endometrial implants by showing antioxidant and anti-inflammatory effects on hi stopathological damage and fibrosis. Key words: endometriosis, rat, adalimumab, antioxidant effect, fibrillin-1 Original papers The effects of adalimumab on the rat autotransplantation endometriosis model: A p lacebo-controlled randomized study Selçuk KaplanA–F , Pınar KırıcıC– E, Ahmet TürkB,C Faculty of Medicine, Adıyaman University, Turkey A – research concept and design; B – collection and/or assembly of data; C – data analysis and interpretation; D – writing the article; E – critical revision of the article; F – final approval of the article Advances in Clinical and Experimental Medicine, ISSN 1899–5276 (print), ISSN 2451–2680 (online) Adv Clin Exp Med. 2022;31(4):417–426 S. Kaplan, P . Kırıcı, A. Türk. Adalimumab on experimental endometriosis 418

Endometriosis is a common gynecological pathology af - fecting 5–10% of women in the reproductive age. 1 It causes symptoms such as chronic pelvic pain, dysmenorrhea, dys- pareunia, and infertility.2 It has negative effects on ovarian reserve, tubal anatomy, embryo quality, and implantation.3 The pathophysiology of endometriosis is still not entirely clear and several theories have been proposed. It has been stated that proinflammatory cytokines play a role in the pathophys- iology of endometriosis. 4–6 There are cytokines responsible for inflammatory reactions and tissue neovascularization. Interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α) have been previously studied in the pathogenesis of endome- triosis. 7 The estrogenic microenvironment activates perito- neal macrophages with secretion of TNF-α and IL-1, which are pro-inflammatory cytokines. The increase in the level of IL-6 and TNF-α in the peritoneal fluid of patients with abnormal immune cell activity shows the role of cytokines in the pathogenesis. 8–10 Endometriosis is a pathology caused by the abnormal proliferation of endometrial tissue outside the uterine cavity. 1 Transforming growth factor beta (TGF-β) plays a key role in the pathological growth of many fibrotic tissues. 11 The TGF-β stimulates the expression of extra - cellular matrix proteins. 12,13 Its receptors have been de - tected in leiomyomas and myometrium, and it has been shown that estrogen and TGF-β expression are increased in endometriosis, and TGF-β activity mediates the effects of estrogen. 14 This interaction may play a role in the de- velopment of endometriosis. Fibrillin-1 is a protein that indicates the activation of TGF-β. 15 Adalimumab is a fully human immunoglobulin G (IgG)1 neutralizing monoclonal antibody specific for TNF-α. 16,17 It is used in the treatment of many autoimmune diseases, such as rheumatoid arthritis, Crohn’s disease and psori - atic arthritis. 16 In previous experimental studies in rats, agents such as etanercept and infliximab have been re - ported to decrease TNF-α levels in peritoneal fluid in rats with endometriosis. 18,19 As far as we know, there is no study reporting the relationship between histopathological and biochemical changes and adalimumab in endometriosis.

The aim of this study is to determine whether adalim - umab can be an effective medical treatment agent, by ex - amining its histopathological and biochemical effects on endometriosis.

The experiments in this study were carried out in accor - dance with the National Institutes of Health (NIH) animal research guidelines and were approved by  Adıyaman Training and Research Hospital Ethics Commitee (ap - proval No. 2019/062, December 26, 2019). Animals and experimental protocol Twenty-eight Wistar albino female rats, 10–12-week old, weighing 250–280 g, were divided into 4 groups with 7 animals in each group. No procedures were performed for 7 days to ensure the adaptation of animals. Rats were housed at 20 ±22°C room temperature during the adap - tation and experimental period, in rooms with 12-hour light and 12-hour dark light cycle, with food and water ad libitum. The animals were classified into 4 groups (control group, endometriosis group, endometriosis + adalimumab group, and adalimumab group). All rats were anesthetized by intramuscular adminis - tration of 60 mg/kg ketamine hydrochloric acid (Ketalar; Warner-Lambert, Istanbul, Turkey) and 7 mg/kg xylazine hydrochloric acid (Rompun; Bayer, Istanbul, Turkey). In group 1 (control group, n = 7), the pelvic region was opened with laparotomy and the adnexa were localized as the right and left adnexa. After the adnexa was localized with the right and left uterine horn, the abdominal wall was closed with 4-0 nylon sutures. No action was taken until the end of the experiment. In group 2 (endometriosis group, n = 7), the autotrans - plantation method was used for the induction of endo - metriosis. The reproductive cycles of the animals were controlled by vaginal smear and the rats in the estrus phase were selected. After general anesthesia, a vertical incision was made to expose the uterus. Both uterine horns were re- moved from the cervix to the point located about 1 cm from the ovaries. Electrocoagulation was used for hemostasis. The uterine horns were divided longitudinally, exposing the endometrium. Without removing the myometrium, en- dometrial segment (5 × 5 mm) was implanted into the peri- toneal surface of the right abdominal wall, so that the en - dometrium came into contact with the peritoneal surface. Both ends of the implants were fixed to the interior with 6-0 nonabsorbable polypropylene suture. 20 All rats were allowed to recover for 4 weeks following surgical induction of endometriosis. At the end of the 4 weeks, the rats were operated to observe the growth of endometriotic implants. The equation: 6 × length × width × height of the implant was used to measure the surface areas of the implants and calculate the endometriotic volume. After the endometri - otic lesions were photographed, the size of the lesion was recorded and the peritoneal cavity was closed. No proce - dure was performed on rats for 4 weeks after the develop - ment of endometriosis. In group 3 (endometriosis + adalimumab group, n = 7), after the reproductive cycles of the animals were controlled by vaginal smear and the rats in the estrous phase were selected, the endometriosis induction was performed using autotransplantation method. At the end of the four-week Adv Clin Exp Med . 2022;31(4):417–426 419 period, after calculating the endometriotic volume and photographing the lesions, 5 mg/kg adalimumab was ad - ministered intraperitoneally (ip.) for 4 weeks. 21 In group 4 (adalimumab group, n = 7), after the ad - nexa was localized with the right and left uterine horn, the abdominal wall was closed with 4-0 nylon sutures and 5 mg/kg adalimumab was administered ip. every day for 4 weeks, to start at the same time as group 2. Histopathological evaluation The excised endometrial implants were fixed with 10% formalin solution upon histopathological examination. Sections approx. 5-μm thick were taken from a formalin- fixed endometriotic implant. Samples were stained with hematoxylin and eosin (H&E) and examined under light microscopy. Histopathological scoring was done 22 based on a following rating scale: +3: a well-preserved epithelial layer; +2: a moderately-preserved epithelial layer (leukocyte infiltrated epithelium); +1: a poorly-preserved epithelial layer (sparse epithelial cell); 0: no epithelial cells. Immunohistochemical examination For fibrillin-1 antigen retrieval, sections were rehydrated, then boiled in a microwave oven (750 W) 7 times for 5 min each in citrate buffer solution (pH 6). Sections were cooled at room temperature for 20 min, washed 3 times for 5 min each with phosphate-buffered saline (PBS; P4417; Sigma Chemical Co., St. Louis, USA), then incubated for 5 min with hydrogen peroxide block solution (TA-125-HP; Lab Vision Corp., San Francisco, USA) to block endogenous peroxidase activity. Then, the sections were washed 3 times for 5 min each with PBS. After applying Ultra V Block (TA-125-UB; Lab Vision Corp.) for 5 min, sections were incubated with primary antibodies for fibrillin-1 (rabbit polyclonal bs-1157R; Bioss Antibodies, Woburn, USA) and diluted 1:200 at room temperature for 60 min in a humid environment. After being washed with PBS 3 times for 5 min each, the sections were incubated at room tempera - ture for 30 min in a humid environment with secondary antibody (biotinylated goat anti-mouse/rabbit IgG, TP- 125-BN; Lab Vision Corp.). Sections were washed with PBS 3 times for 5 min each and incubated at room temperature for 30 min in a humid environment with streptavidin per - oxidase (TS-125-HR; LabVision Corp.) and then placed in PBS. The 3-amino-9-ethylcarbazole (AEC) substrate + AEC chromogen (AEC substrate, TA-015 and HAS, AEC chromogen, TA-002-HAC; Lab Vision Corp.) solution was dripped on the sections. The sections were washed with PBS. Sections were counterstained with Mayer’s hematoxy- lin, passed through PBS and distilled water and mounted with Large Volume Vision Mount (TA-125-UG; Lab Vision Corp.). Sections were evaluated and photographed using a digital microscope camera (Leica DFC295; Leica Camera AG, Wetzlar, Germany). The histoscore, which reflects the prevalence of immunoreactivity of fibrillin-1 on the tis - sue, was based on the rating scale: 0.1: < 25%; 0.4: 26−50%; 0.6: 51−75%; 0.9: 76−100%, and intensity of immunoreac - tivity: 0: unstained; 0.5: little staining; 1: some staining; 2: moderate staining; 3: strong staining. The histoscore was measured using the following equation: histoscore = prevalence × intensity of immunoreactivity. Determination of malondialdehyde (MDA) level Determination of malondialdehyde level was performed by applying the Esterbauer method, which is a lipid per - oxidation measurement method. 23 Malondialdehyde re - acting with thiobarbituric acid at 90–95°C forms pink- colored chromogen. Fifteen minutes later, the absorbances of the rapidly cooled samples were read spectrophotomet - rically at 532 nm. The results are expressed in nmol/g. Determination of total antioxidant status (TAS) and total oxidant status (TOS) levels Total antioxidant status and total oxidant status were measured in serum samples using enzyme-linked immu - noassay (ELISA) method. The TAS (Rat TAS Catalog No. YLA3889Ra; YL Biotechnology Co., Ltd, Shanghai, China) and TOS (Rat TOS Catalog No. YLA1892Ra; YL Biotech- nology Co., Ltd) levels were measured in accordance with the procedures specified in the catalog of kits. The mea - surement range of the Rat TAS ELISA kit was: 1–300 pg/mL, intra-assay coefficient of variation (CV) <10%, inter-assay CV < 12%, sensitivity 0.54 pg/mL. The measurement range of the Rat TOS ELISA kit was 0.02–60 U/mL, intra-assay CV < 10%, inter-assay CV < 12%, sensitivity 0.013 U/mL. The  automatic washer BioTek ELx50 (BioTek Instru - ments, Winooski, USA) was used for plate washing, while ChroMate Microplate Reader P4300 devices (Awareness Technology, Palm City, USA) were used for absorbance readings. The unit of test results is specified for serum samples in U/mL. Statistical analyses The IBM SPSS v. 22 software (IBM Corp., Armonk, USA) program was used to analyze the data. The Shapiro–Wilk test was used as a normal distribution test. The Shapiro– Wilk test results for MDA measurement were reported as p = 0.830 for group 1, p = 0.898 for group 2, p = 0.881 for group 3, and p = 0.716 for group 4. The Shapiro–Wilk test results for TAS measurement were 0.274 for group 1, 0.540 for group 2, 0.648 for group 3, and 0.355 for group 4. The Shapiro–Wilk test results for TOS measurement were reported as p = 0.707 for group 1, p = 0.598 for group 2, p = 0.700 for group 3, and p = 0.944 for group 4. The Sha - piro–Wilk test results for fibrillin-1 measurement were S. Kaplan, P . Kırıcı, A. Türk. Adalimumab on experimental endometriosis 420 reported as p = 0.812 for group 1, p = 0.652 for group 2, p = 0.717 for group 3, and p = 0.941 for group 4. Levene’s homogeneity test was performed, in which the data met the assumption of normal distribution for each group, and the results were p = 0.170 for MDA, p = 0.050 for TAS, p = 0.654 for TOS, and p = 0.191 for fibrillin-1 measure - ment. It was observed that the variances were homogeneous. One-way analysis of variance (ANOVA) test (post hoc Bon- ferroni test) was used in the analysis of the data conforming to the normal distribution. The score variable does not show a normal distribution. The p-value of the score variable is <0.001. Spearman’s correlation test was used for the val- ues where the score did not show normal distribution, and Pearson’s correlation test was used for the others. The value of p < 0.05 was considered statistically significant.

Histopathological scoring The H&E staining and immunohistochemistry stain - ing histopathological images were shown in  Fig. 1 and Fig. 2 . There was a statistically significant difference between the measurements in different groups. A sta - tistical difference was observed between group 2 and group 3 (p < 0.001) ( Table 1). When group 1 and group 2 were compared, the increase in histopathological damage in group 2 was statistically significant (p < 0.001). When group 3 and group 2 were compared, the histopathologi - cal damage score was significantly decreased in group 3 (p < 0.001). Fig. 1. Excised endometrial implants were stained with hematoxylin and eosin (H&E). Accordingly, group 1 (control) (1A) and group 4 (adalimumab) (1C) were of normal appearance. In group 2 (endometriosis) (1B), severe epithelial damage (black arrow) and leukocyte infiltration (black star) were observed. In group 3 (endometriosis + adalimumab) (1D), epithelial damage and leukocyte infiltration were observed to decrease Adv Clin Exp Med . 2022;31(4):417–426 421 Fig. 2. Examination of immunohistochemical staining for fibrillin-1 immunoreactivity under light microscopy; fibrillin-1 immunoreactivity (black arrow) was observed; 2A. Group 1 (control); 2D. Group 3 (endometriosis + adalimumab); 2B. Group 2 (endometriosis); 2C. Group 4 (adalimumab) Table 1. Comparison of biochemical measurements and fibrillin-1 scores by groups* Group Fibrillin-1 MDA TAS TOS Group 1 (n = 7) mean 2.31 17.92 1.18 12.98 SD 0.77 0.99 0.04 1.06 median 0.71 18.01 1.17 13.26 Group 2 (n = 7) mean 5.51 25.02 0.43 19.75 SD 2.61 1.61 0.20 1.48 median 3.30 25.30 0.41 20.14 Group 3 (n = 7) mean 3.64 19.86 0.81 17.68 SD 1.47 1.77 0.14 1.81 median 1.66 20.10 0.81 17.60 Group 4 (n = 7) mean 0.93 16.88 1.29 15.55 SD 0.14 0.94 0.12 1.26 median 0.11 16.78 1.24 15.52 p-value for each group <0.001 <0.001 <0.001 <0.001 df (total) for each group 27 27 27 27 f for each group 12.741 48.104 53.812 28.671 SD – standard deviation; df – degrees of freedom; MDA – malondialdehyde; TAS – total antioxidant status; TOS – total oxidant status; ADA – adalimumab; group 1 – control; group 2 – endometriosis; group 3 – endometriosis + ADA; group 4 – ADA; *one-way analysis of variance (ANOVA) test. S. Kaplan, P . Kırıcı, A. Türk. Adalimumab on experimental endometriosis 422 Macroscopic examination The mean size of rats endometriotic implants in group 2 was 0.77 ±0.04 mm 2. After adalimumab treatment, it mea- sured 0.32 ±0.002 mm 2. This decrease was statistically significant (p = 0.032) ( Fig. 3). Biochemical analysis Post hoc one-way ANOVA results for biochemical mea- surements are given in Table 2 . MDA level The MDA levels significantly increased in group 2 com - pared with group 1 (p < 0.001). The MDA values w ere significantly decreased in group 3 compared with group 2 (p  0.05) ( Table 1, Table 2). TAS level The TAS levels were significantly decreased in group 2 compared with group 1 (p < 0.001). The TAS values i n- creased in group 3 compared to group 2 (p  0.05) ( Table 1, Table 2). TOS level The distribution of scores in respective groups is given in  Table 3. The TOS levels were significantly increased in group 2 compared with group 1 (p < 0.001). The TOS values i n group 2 were significantly decreased compared with group 4 (p  0.05). The TOS values w ere significantly increased in group 4 compared with group 1 (p = 0.016) (Table 1, Table 2). When histopathological scores and biochemical values were compared, there was a strong negative correlation between MDA value and TOS value and a strong positive correlation between MDA value and TAS value (p < 0.001) (Table 3). Immunohistochemistry examination score In the immunohistochemistry examination, fibrillin-1 scores differed significantly for 4 groups. According to the post hoc one-way ANOVA analysis between groups, fibrillin-1 activity increased in groups 2 and 3 compared to group 1 (p < 0.001). Moreover, fibrillin-1 immune reac - tivity decreased in group 3 compared to group 2 (p < 0.001) (Table 3). Fig. 3. A,B. Endometriotic foci developed as a result of autotransplantation; C,D. After adalimumab treatment, the size of the endometriotic foci decreased Adv Clin Exp Med . 2022;31(4):417–426 423

In this study, the effect of adalimumab on histopatho - logical changes in endometriotic implants and its antioxi - dant effects were investigated. The size of endometriotic implants decreased after adalimumab treatment, as shown with macroscopic examination. Histopathological damage score increased in rats with experimental endometriosis and decreased with adalimumab administration. Fibrillin-1 score was increased in endometriotic implants, but fibril - lin-1 score decreased in endometriotic implants treated with adalimumab. In addition, adalimumab decreased MDA levels and increased TAS levels in endometriotic implants. These findings show the  histopathological Table 2. Post hoc one-way analysis of variance (ANOVA) of biochemical values and fibrillin-1 scores by groups Dependent variable Group (I) Group (J) Average difference (I–J) p-value MDA group 1 group 2 group 3 group 4 –7.10* –1.94 1.03 <0.001 0.087 1.000 group 2 group 1 group 3 group 4 7.10* 5.15* 8.13* <0.001 <0.001 <0.001 group 3 group 1 group 2 group 4 1.94 –5.15* 2.97* 0.087 <0.001 0.003 group 4 group 1 group 2 group 3 –1.03 –8.13* –2.97* 1.000 <0.001 0.003 TAS group 1 group 2 group 3 group 4 0.74* 0.36* –0.11 <0.001 <0.001 0.907 group 2 group 1 group 3 group 4 –0.74* –0.38* –0.86* <0.001 <0.001 <0.001 group 3 group 1 group 2 group 4 –0.36* 0.38* –0.48* <0.001 <0.001 <0.001 group 4 group 1 group 2 group 3 0.11 0.86* 0.48* 0.907 <0.001 <0.001 TOS group 1 group 2 group 3 group 4 –6.77* –4.70* –2.56* <0.001 <0.001 0.016 group 2 group 1 group 3 group 4 6.77* 2.07 4.20* <0.001 0.075 <0.001 group 3 group 1 group 2 group 4 4.70* –2.07 2.13 <0.001 0.075 0.062 group 4 group 1 group 2 group 3 2.56* –4.20* –2.13 0.016 <0.001 0.062 Fibrillin-1 group 1 group 2 group 3 group 4 –1.28* –1.15* 0.37 <0.001 <0.001 0.083 group 2 group 1 group 3 group 4 1.28* 0.12 1.65* <0.001 1.000 <0.001 group 3 group 1 group 2 group 4 1.15* –0.12 1.53* <0.001 1.000 <0.001 group 4 group 1 group 2 group 3 –0.37 –1.65* –1.53* 0.083 <0.001 <0.001 MDA – malondialdehyde; TAS – total antioxidant status; TOS – total oxidant status; ADA – adalimumab; group 1 – control; group 2 – endometriosis; group 3 – endometriosis + ADA; group 4 – ADA; I – group designated for comparison; J – other groups compared; * groups with statistically significant differences between them. Values in bold show statistically significant differences between groups. S. Kaplan, P . Kırıcı, A. Türk. Adalimumab on experimental endometriosis 424 improvement and antioxidant activity caused by adalim - umab treatment in endometriotic implants. Oxidative stress and inflammation play an important role in the pathogenesis of endometriosis. 24–26 Moreover, studies have shown that erythrocytes, apoptotic endo - metrial tissue, cell debris in the peritoneal cavity, and macrophages induce oxidative stress and inflammation, and cause endometriosis. 26 It is known that the balance between reactive oxygen species (ROS) and antioxidants is lost in the development of endometriosis. 27 The pres - ence of ROS in the environment affects gene expression, causing protein dysfunction and cellular damage. 26–28 This oxidative stress can be both a cause and a conse - quence of endometriosis. 26 In addition, the role of mi - tophagy and autophagy in the pathophysiology of endo - metriosis supports the role of oxidative damage. 28 It has been hypothesized that eliminating oxidative stress may reduce the histopathological grade in endometrial im - plants and many studies have been conducted on this subject. 27,29,30 Proinflammatory cytokines such as IL-1, IL-6, IL-8, and TNF-α have also been shown to play a role in the pathol - ogy of  endometriosis. 31 It  has been demonstrated that there is an increase in TNF-α levels in the peritoneal fluids of women with endometriosis. 32 It is thought that endo - metrial cell proliferation increases and endometriotic le - sions develop by inducing IL-8 secretion with the increase of TNF-α. 33,34 In previous studies using etanercept, which has an anti-TNF-α activity, it was reported that endome - triotic implants were reduced and histopathological scores decreased. 35 In another study, etanercept was reported to de- crease MDA levels in endometriotic focus. 36 In our study, adalimumab treatment has decreased endometriotic implant dimensions, histopathological damage score and fibrillin-1 score, which is a fibrosis marker. Fibrillin-1 has been associated with heart and liver fi - brosis, and has been shown to cause the expression of ex - tracellular matrix proteins in various studies in rats. 37,38 In addition, it has been previously observed that topical application of estrogen increases the activity of fibrillin-1 and other extracellular matrix proteins. 39 Moreover, it was demonstrated that fibrillin-1 activity increased in propor - tion to the size in leiomyomas. 40 In our study, the increase in fibrillin-1 score in endometriotic implants may be re - lated to the role of the estrogenic microenvironment in en - dometrial implant development. Since estrogen levels were not measured in our study, large studies can be conducted to investigate this hypothesis. Adalimumab is a drug that is effective both as mono - therapy and in combination with disease-modifying anti - rheumatic drugs in the treatment of many chronic, inflam - matory, immune-mediated diseases. 16 It has been reported that adalimumab decreases cell proliferation and increases the function of natural immune pathways by decreased IL-8 levels. 41 Considering the role of proinflammatory cytokines in the pathogenesis of endometriosis, it is not surprising that endometriotic implants and histopatho - logical score decreased along with adalimumab treatment. Moreover, the immunomodulatory activity of adalimumab may demonstrate decreased fibrillin-1 activation in endo - metriotic implants.

This study has some limitations. The fibrillin-1 score is  established primarily with immunohistochemistry staining, but there were no polymerase chain reaction (PCR) tests measuring the fibrillin-1 protein expressions. Second, the study was experimentally performed in rats. In order to generalize the results to society, studies should be carried out primarily with large human populations.

Adalimumab, through its antioxidant and anti-inflam - matory effects, plays an important role in the treatment of histopathological damage and fibrosis in endometri - otic implants developed experimentally. It can be used as a nonhormonal agent in the treatment of endometriotic implants. However, experiments with different parameters are needed in large groups of animals and humans. Table 3. Correlations between biochemical measurements* Variables Score MDA TAS TOS Score r 1 −0.834 0.840 −0.680 p-value – <0.001 <0.001 <0.001 MDA r – 1 −0.863 0.740 p-value – – <0.001 <0.001 TAS r – – 1 −0.766 p-value – – – <0.001 TOS r – – – 1 p-value – – – – MDA – malondialdehyde; TAS – total antioxidant status; TOS – total oxidant status; * Spearman’s and Pearson’s correlation test. Since the score did not show normal distribution, the values in bold were obtained with the Spearman’s test, and the other results were obtained with the Pearson’s correlation test. Adv Clin Exp Med . 2022;31(4):417–426 425 ORCID iDs Selçuk Kaplan  https://orcid.org/0000-0002-2887-6165 Pınar Kırıcı  https://orcid.org/0000-0001-7616-4181 Ahmet Türk  https://orcid.org/0000-0003-0903-3522

1. L iu Y, Zhang Z, Lu X, Meng J, Qin X, Jiang J. Anti-nociceptive and anti-inflammatory effects of sulforaphane on sciatic endometriosis in a rat model. Neurosci Lett . 2020;723:134858. doi:10.1016/j.neulet. 2020.134858 2. M atarese G, De Placido G, Nikas Y, Alviggi C. Pathogenesis of endo - metriosis: Natural immunity dysfunction or autoimmune disease? Trends Mol Med . 2003;9(5):223–228. doi:10.1016/s1471-4914(03) 00051-0 3. G auché-Cazalis C, Koskas M, Cohen Scali S, Luton D, Yazbeck C. Endo - metriosis and implantation: Myths and facts. Middle East Fertil Soc J. 2012;17:79e81. doi:10.1016/j.mefs.2012.04.002 4. C alhaz-Jorge C, Costa AP , Barata M, Santos MC, Melo A, Palma-Carlos ML. Tumour necrosis factor alpha concentrations in the peritoneal fluid of infertile women with minimal or mild endometriosis are lower in patients with red lesions only than in patients without red lesions. Hum Reprod. 2000;15(6):1256 –1260. doi:10.1093/humrep/15.6.1256 5. G azvani R, Templeton A. Peritoneal environment, cytokines and angio - genesis in the pathophysiology of endometriosis. Reproduction. 2002; 123(2):217–226. doi:10.1530/rep.0.1230217 6. T askin MI, Gungor AC, Adali E, Yay A, Onder GO, Inceboz U. A human - ized anti-interleukin 6 receptor monoclonal antibody, tocilizumab, for the treatment of endometriosis in a rat model. Reprod Sci. 2016; 23(5):662–669. doi:10.1 177/19337191 15612134 7. L aganà AS, Vitale SG, Salmeri FM, et al. Unus pro omnibus, omnes pro uno: A novel, evidence-based, unifying theory for the pathogen- esis of endometriosis. Med Hypotheses. 2017;103:10–20. doi:10.1016/j. mehy.2017.03.032 8. K alu E, Sumar N, Giannopoulos T, et al. Cytokine profiles in serum and peritoneal fluid from infertile women with and without endometri - osis. J Obstet Gynaecol Res . 2007;33(4):490–495. doi:10.1111/j.1447- 0756.2007.00569.x 9. M ahnke JL, Dawood MY, Huang JC. Vascular endothelial growth fac - tor and interleukin-6 in peritoneal fluid of women with endometrio - sis. Fertil Steril. 2000;73(1):166–170. doi:10.1016/s0015-0282(99)00466-5 10. O thman Eel-D, Hornung D, Salem HT, Khalifa EA, El-Metwally TH, Al-Hendy A. Serum cytokines as biomarkers for nonsurgical predic - tion of endometriosis. Eur J Obstet Gynecol Reprod Biol. 2008;137(2): 240–246. doi:10.1016/j.ejogrb.2007.05.001 11. B ranton MH, Kopp JB. TGF-beta and fibrosis. Microbes Infect . 1999; 1(15):1349–1365. doi:10.1016/s1286-4579(99)00250-6 12. S ozen I, Arici A. Interactions of cytokines, growth factors, and the extracellular matrix in the cellular biology of uterine leiomyomata. Fertil Steril. 2002;78(1):1–12. doi:10.1016/s0015-0282(02)03154-0 13. Lu o X, Ding L, Xu J, Chegini N. Gene expression profiling of leio - myoma and myometrial smooth muscle cells in response to trans - forming growth factor-beta. Endocrinology . 2005;146(3):1097–1118. doi:10.1210/en.2004-1377 14. C hegini N, Ma C, Tang XM, Williams RS. Effects of GnRH analogues, ‘add-back’ steroid therapy, antiestrogen and antiprogestins on leio- myoma and myometrial smooth muscle cell growth and transform- ing growth factor-beta expression. Mol Hum Reprod . 2002;8(12): 1071–1078. doi:10.1093/molehr/8.12.1071 15. K aartinen V, Warburton D. Fibrillin controls TGF-beta activation. Nat Genet. 2003;33(3):331–332. doi:10.1038/ng0303-331 16. M atsumoto T, Motoya S, Watanabe K, et al. Adalimumab monother - apy and a combination with azathioprine for Crohn’s disease: A pro- spective, randomized trial. J Crohns Colitis . 2016;10(11):1259–1266. doi:10.1093/ecco-jcc/jjw152 17. B urmester GR, Landewé R, Genovese MC, et al. Adalimumab long- term safety: Infections, vaccination response and pregnancy out - comes in patients with rheumatoid arthritis. Ann Rheum Dis . 2017; 76(2):414–417. doi:10.1136/annrheumdis-2016-209322 18. B arrier BF, Bates GW, Leland MM, Leach DA, Robinson RD, Propst AM. Efficacy of anti-tumor necrosis factor therapy in the treatment of spontaneous endometriosis in baboons. Fertil Steril. 2004;81(Suppl 1): 775–779. doi:10.1016/j.fertnstert.2003.09.034 19. F alconer H, Mwenda JM, Chai DC, et al. Treatment with anti-TNF monoclonal antibody (c5N) reduces the extent of induced endome - triosis in the baboon. Hum Reprod. 2006;21(7):1856–1862. doi:10.1093/ humrep/del044 20. P elch KE, Sharpe-Timms KL, Nagel SC. Mouse model of surgically- induced endometriosis by auto-transplantation of uterine tissue. J Vis Exp. 2012;59:e3396. doi:10.3791/3396 21. Y ilmaz M, Tekekoglu S, Herek O, Ozmen O, Sahinduran Ş, Buyukoglu T. Ameliorative effect of adalimumab on experimentally induced acute pancreatitis in rats. Pancreas. 2010;39(8):1238–1242. doi:10.1097/MPA. 0b013e3181dec1a6 22. Yavuz E, Oktem M, Esinler I, Toru SA, Zeyneloglu HB. Genistein causes regression of endometriotic implants in the rat model. Fertil Steril. 2007;88(4 Suppl):1129–1134. doi:10.1016/j.fertnstert.2007.01.010 23. E sterbauer H, Cheeseman KH. Determination of aldehydic lipid per - oxidation products: Malonaldehyde and 4-hydroxynonenal. Methods Enzymol. 1990;186:407–421. doi:10.1016/0076-6879(90)86134-h 24. Y un BH, Chon SJ, Choi YS, Cho S, Lee BS, Seo SK. Pathophysiology of endometriosis: Role of high mobility group box-1 and toll-like receptor 4 developing inflammation in endometrium. PLoS One. 2016; 11(2):e0148165. doi:10.1371/journal.pone.0148165 25. S antanam N, Kavtaradze N, Murphy A, Dominguez C, Parthasara - thy S. Antioxidant supplementation reduces endometriosis-related pelvic pain in humans. Transl Res . 2013;161(3):189–195. doi:10.1016/j. trsl.2012.05.001 26. Donnez J, Binda MM, Donnez O, Dolmans MM. Oxidative stress in the pelvic cavity and its role in the pathogenesis of endometriosis. Fertil Steril. 2016;106(5):1011–1017. doi:10.1016/j.fertnstert.2016.07.1075 27. H arlev A, Gupta S, Agarwal A. Targeting oxidative stress to treat endo - metriosis. Expert Opin Ther Targets. 2015;19(11):1447–1464. doi:10.1517/ 14728222.2015.1077226 28. S iracusa R, D’Amico R, Impellizzeri D, et al. Autophagy and mitoph - agy promotion in a rat model of endometriosis. Int J Mol Sci. 2021; 22(10):5074. doi:10.3390/ijms22105074 29. C ordaro M, Trovato Salinaro A, Siracusa R, et al. Hidrox® and endo - metriosis: Biochemical evaluation of oxidative stress and pain. Antioxidants (Basel). 2021;10(5):720. doi:10.3390/antiox10050720 30. S iracusa R, D’Amico R, Cordaro M, et al. The methyl ester of 2-cyano- 3,12-dioxooleana-1,9-dien-28-oic acid reduces endometrial lesions development by modulating the NFkB and Nrf2 pathways. Int J Mol Sci. 2021;22(8):3991. doi:10.3390/ijms22083991 31. G enovese T, Siracusa R, D’Amico R, et al. Regulation of inflamma - tory and proliferative pathways by fotemustine and dexametha - sone in endometriosis. Int J Mol Sci. 2021;22(11):5998. doi:10.3390/ ijms22115998 32. Dmowski PW, Braun DP. Immunology of endometriosis. Best Pract Res Clin Obstet Gynaecol. 2004;18(2):245–263. doi:10.1016/j.bpobgyn. 2004.02.001 33. K yama CM, Overbergh L, Debrock S, et al. Increased peritoneal and endometrial gene expression of biologically relevant cytokines and growth factors during the menstrual phase in women with endo - metriosis. Fertil Steril. 2006;85(6):1667–1675. doi:10.1016/j.fertnstert. 20 05.11.0 6 0 34. A rici A, Oral E, Attar E, Tazuke SI, Olive DL. Monocyte chemotactic protein-1 concentration in peritoneal fluid of women with endo - metriosis and its modulation of expression in mesothelial cells. Fer- til Steril. 1997;67(6):1065–1072. doi:10.1016/s0015-0282(97)81440-9 35. A rici A. Local cytokines in endometrial tissue: The role of interleu - kin-8 in the pathogenesis of endometriosis. Ann N Y Acad Sci. 2002; 955:101– 4 0 6 . doi:10.1111/j.1749 - 6 632 . 20 02 .tb 02770. x 36. E raldemir FC, Keleş CD, Kum T, Vural B, Baydemir C. The effect of etan - ercept treatment on serum malonaldialdehyde levels in experi - mental endometriosis rat model. KOU Sag Bil Derg . 2015;1(1):26–29. doi:10.30934/kusbed.349539 37. L orena D, Darby IA, Reinhardt DP , Sapin V, Rosenbaum J, Desmoulière A. Fibrillin-1 expression in normal and fibrotic rat liver and in cultured hepatic fibroblastic cells: Modulation by mechanical stress and role in cell adhesion. Lab Invest. 2004;84(2):203–212. doi:10.1038/labinvest. 3700023 38. B ouzeghrane F, Reinhardt DP , Reudelhuber TL, Thibault G. Enhanced expression of fibrillin-1, a constituent of the myocardial extracel - lular matrix in fibrosis. Am J Physiol Heart Circ Physiol . 2005;289(3): H982–H991. doi:10.1152/ajpheart.00151.2005 S. Kaplan, P . Kırıcı, A. Türk. Adalimumab on experimental endometriosis 426 39. S on ED, Lee JY, Lee S, et al. Topical application of 17beta-estradiol increases extracellular matrix protein synthesis by stimulating TGF- beta signaling in aged human skin in vivo. J Invest Dermatol . 2005; 124(6):1149 –1161. doi:10.1111/j.0 022-202 X . 20 05. 23736 . x 40. Z hao Y, Wen Y, Polan ML, Qiao J, Chen BH. Increased expression of latent TGF-beta binding protein-1 and fibrillin-1 in human uterine leio- myomata. Mol Hum Reprod. 2007;13(5):343–349. doi:10.1093/molehr/ gam007 41. H endriks AG, van der Velden HM, Wolberink EA, et al. The effect of adalimumab on key drivers in the pathogenesis of psoriasis. Br J Dermatol. 2014;170(3):571–580. doi:10.1111/bjd.12705