Croton grewioides essential oil and anethole reduce oxidative stress and improve growth of bovine primordial follicles during culture of ovarian tissue

Objectives This study aims to evaluate the effects of Croton grewioides essential oil (CGEO) and anethole on follicle survival, growth, and oxidative stress in cultured bovine ovarian tissues. Methods Ovarian tissues were cultured for 6 days in a medium supplemented with different concentrations (1, 10, 100, or 1000 mu g mL(-1)) of CGEO or anethole and then, follicular survival and growth, collagen content, and stromal cell density in ovarian tissues cultured in vitro were evaluated by histology. The mRNA levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase 1 (GPX1), peroxirredoxin 6 (PRDX6), and nuclear factor erythroid 2-related factor 2 (NRF2) were evaluated by real-time PCR. The activity of SOD, CAT, glutathione peroxidase (GPx), and thiol concentrations were investigated. Key findings Ovarian tissues cultured with 1 mu g mL-1 CGEO or anethole had a higher percentage of healthy follicles than those cultured in a control medium (P < .05). The 1 <mu>g mL(-1) CGEO also increased the number of stromal cells, collagen fibers, and thiol levels. Anethole (1 mu g mL(-1)) increased CAT activity and reduced that of GPx. The activity of SOD was reduced by CGEO. In contrast, 1 mu g mL(-1 )anethole reduced mRNA for CAT, PRDX1, and NRF2 (P < .05). In addition, 1 <mu>g mL(-1) CGEO reduced mRNA for CAT, PRDX6, and GPx1 (P < .05). Conclusions The presence of 1 <mu>g mL-1 anethole or CGEO in a culture medium promotes follicle survival and regulates oxidative stress and the expression of mRNA and activity of antioxidant enzymes in cultured bovine ovarian tissues.