Seasonal changes in some oxidant and antioxidant parameters during folliculogenesis in Egyptian buffalo.

Knowledge regarding oxidant and antioxidant status in follicular fluid remains limited and its studying in vivo should enhance our understanding of the impact of them on fertility and contribute to optimization of in vitro maturation conditions. The present study was conducted on follicular fluid and serum samples obtained from 708 buffaloes. They were examined for Malondialdehyde (MDA) as indicator of lipid peroxidation as well as superoxide dismutase (SOD) and total antioxidant capacity (TAC) as antioxidant markers. The obtained results revealed that MDA levels and SOD activity in follicular fluid decreased significantly as follicle size increased, while TAC increased significantly with the increase in follicular size. Whereas MDA level was significantly higher in summer, the TAC was significantly higher in spring. Moreover, MDA levels and SOD activities were significantly higher in the follicular fluid from different size follicles during the luteal phase than follicular phase. MDA levels in medium follicles in luteal phase and small follicles in follicular and luteal phases were significantly higher in summer than other seasons. Serum MDA levels were significantly increased in summer. In addition, MDA levels, SOD activities and TAC in serum were significantly higher during luteal phase than follicular phase in summer. TAC levels were significantly higher in follicular fluid than serum, while MDA was significantly lower in follicular fluid than serum. In conclusion, the present study revealed that oxidants/antioxidants balance may play a role in normal follicular development and oxidative stress that occur in summer could be related to reproductive seasonality in buffalo.