Deer Blood Hydrolysate Protects against D-Galactose-Induced Premature Ovarian Failure in Mice by Inhibiting Oxidative Stress and Apoptosis

Background: Premature ovarian failure (POF) is a common disease among women, which can cause many complications and seriously threaten women's physical and mental health. Currently, hormone replacement therapy is the primary treatment for premature ovarian failure. However, the side effects are serious and will increase the chance of breast cancer and endometrial cancer. Deer blood hydrolysate (DBH) is the product of enzymatic hydrolysis of deer blood, has antioxidant, anti-ageing, and anti-fatigue effects, and has the potential to improve premature ovarian failure. Methods: In our experiment, a mouse model of premature ovarian failure was established through intraperitoneal injection of 400 mg/kg/d of D-gal for 42 days. At the same time, different doses of DBH were gavaged to observe its ameliorative effect on premature ovarian failure. Results: The experimental findings indicated that DBH could restore the irregular oestrus cycle of POF mice, improve the abnormal amounts in serum hormones follicle-stimulating hormone (FSH), luteinising hormone (LH), progesterone (P) and estradiol (E2), increase the number of primordial follicles and decrease the number of atretic follicles. In addition, DBH also raised the level of superoxide dismutase (SOD) and reduced the level of malondialdehyde (MDA) and reduced the apoptosis of ovarian granulosa cells in mice. The WB assay results showed that gavage of DBH restored the decrease in the indication of nuclear factor erythroid 2-related factor 2 (Nrf2), Heme Oxygenase-1 (Ho-1), and B-cell lymphoma-2 (Bcl-2) proteins and reduced the elevated expression of Kelch-like ECH-associated protein 1 (Keap1), Bcl-2 associated X protein (Bax), and Cysteinyl aspartate specific proteinase-3 (Caspase-3) proteins that were induced by D-gal. Conclusions: To sum up, the present research indicated that DBH can ameliorate D-gal-induced oxidative stress and apoptosis by regulating the Nrf2/HO-1 signalling pathway and the Bcl-2/Bax/caspase-3 apoptosis pathway, which can be used for further development as a nutraceutical product to improve premature ovarian failure.