Establishment of a mouse model of ovarian oxidative stress induced by hydrogen peroxide

Abstract

Introduction: Oxidative stress, resulting from environmental changes, significantly affects female fertility. Developing a mouse model to study oxidative stress lays the groundwork for research into human reproductive health and livestock fertility.

Materials and methods: In this study, we established and evaluated an oxidative stress model by administering hydrogen peroxide (H₂O₂) to mice. ICR mice of similar age (7-8 weeks old) and average body weight (31.58 ± 1.12 g) were randomly assigned to four groups (A, B, C, and D). Group A served as the control and was injected with a saline solution, while groups B, C, and D received saline solutions containing 0.75%, 1.50%, and 3.0% H₂O₂, respectively, over one week. We measured the body weights of all mice before and after the experimental period.

Results and discussion: Our findings showed that the average body weight of mice in groups A and B increased, while groups C and D experienced weight loss. Group C showed a significantly lower average weight gain compared to groups A and B, and group D exhibited an even more pronounced reduction in weight gain. Although group D had a high mortality rate, there was no significant difference in mortality rates among groups B, C, and D. Serum malondialdehyde (MDA) content increased with higher concentrations of H₂O₂, with a significant difference noted between groups C and A. Catalase (CAT) activity in group B was significantly higher than in group A, while superoxide dismutase (SOD) activity in group C was notably elevated compared to groups A and B. Conversely, glutathione peroxidase (GSH-Px) activity in group C was significantly lower than in both group A and group B. Hematoxylin and eosin (HE) staining revealed changes in ovarian morphology and follicle dynamics. The percentage of atretic follicles in group C was significantly higher than in the control group, and group D had a significantly lower total number of healthy follicles compared to the untreated group. Increased H₂O₂ content resulted in a reduction of ovary size and an irregular appearance in group D.

Conclusion: Based on our findings, treatment with 1.50% H₂O₂ effectively established an oxidative stress model in mice within 1 week. This model serves as a valuable reference for future clinical studies on oxidative stress and reproductive disorders in female animals and humans.

Keywords: antioxidant enzymes; hydrogen peroxide; mouse model; ovary; oxidative stress.