Induction of the Mice Model Regarding the Endometriosis and Assessment of Antioxidant Treatment Effectiveness: An Experimental Protocol

Endometriosis is a chronic hormone-inflammatory disease with known symptoms such as infertility and pelvic pains. It influences the health of the women in their reproductive span, and is characterized by stroma outside the uterus and endometrial glands, physically, psychologically, and socially (1-3). The prevalence of this disease is about 10% and it is reported between 20-90% for women with infertility or pelvic pain (4,5). Three theories were suggested to explain the pathogenesis of endometriosis, including endometrial tissue ectopic transplantation, coelomic metaplasia, and the induction theories. Although retrograde occurs in 90% of women, the disease develops only in some of them. Therefore, various mechanisms such as epigenetic and inflammatory factors, immune disorders, as well as hormones, and environmental factors may contribute to the onset of endometriosis, establishment, progression/ backwardness, symptoms, signs, and the complications of this disease (4,6-10). Oxidative stress has a potential role in the inflammatory process, cell proliferation, and the apoptosis prevention of the endometriotic cell growth of endometrial lesions (11,12). Due to ethical constraints in the trial studies of infertility in women with endometriosis, animal models are valuable tools for controlling the risk factors, outbreak, and pathogenesis of endometriosis (13). The induction models of endometriosis are very diverse, for instance, the induction of peritoneal, ovarian, and subcutaneous, in the forms of autotransplant or hetrotransplant. The ovarian is considered as the most common site for endometriosis while most studies have examined the peritoneal endometriosis induction (14). This study aims to extract an optimum model using in Abstract Objectives: Over the past twenty years, the role of inflammatory, immunologic, and stress oxidative factors in the pathogenesis of endometriosis has been emphasized in the literature. Endometrial induced lesions in the surgical endometriosis model of mice are similar to those observed in women. Therefore, the present study evaluated the effects of vitamin C treatment on the endometriosis mice model. More precisely, it aimed to induce an optimum model of endometriosis using both peritoneal and ovarian approaches and to compare the histological and fertility changes in the first-generation infants of endometriosis induced, sham, and control groups. Finally, the study assessed the influence of vitamin C administration treatment on the induced endometriosis mice model and its first-generation infants. Methods: This experimental study was done in three phases. In the first phase, 32 mice were randomly divided into four groups receiving induced endometriosis through peritoneal approach, induced endometriosis through an ovarian approach, as well as sham and control groups. The histological and fertility characteristics of the first generation of ovarian endometriosis, sham, and control groups were compared in the second phase. Then, the histological and fertility characteristics of those endometriosis induced models receiving vitamin C were compared with the controls, and the first generation of these groups was compared as well. Results: This experimental study began in April 2017 and will be finished in 2020. Conclusions: The results of this study improve our knowledge about the mechanisms involved in endometriosis progressions. The results further provide a comprehensive animal model for further research and assess the therapeutic role of antioxidants.