| Abstract: | Genistein is an isoflavone that has estrogen (E2)‐like activity and is beneficial for follicular development, but little is known regarding its function in oxidative stress (OS)‐mediated granulosa cell (GC) injury. Here, we found that after exposure to H2O2, Genistein weakened the elevated levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), which were regarded as the biomarkers for OS, and rescued glutathione (GSH) content and GSH/GSSG ratio accompanying with a simultaneous increase in cyclic adenosine monophosphate (cAMP) level, whereas addition of protein kinase A (PKA) inhibitor H89 impeded the effects of Genistein on the levels of ROS and MDA. Further analysis evidenced that Genistein enhanced the activities of antioxidant enzymes superoxide dismutase (SOD), GSH‐peroxidase (GSH‐Px), and catalase (CAT) in H2O2‐treated GCs, but this enhancement was attenuated by H89. Under OS, Genistein improved cell viability and lessened the apoptotic rate of GCs along with a reduction in the activity of Casp3 and levels of Bax and Bad messenger RNA (mRNA), while H89 reversed the above effects. Moreover, Genistein treatment caused an obvious elevation in mitochondrial membrane potential (MMP) followed by a decline in the levels of intracellular mitochondrial superoxide, but H89 inhibited the regulation of Genistein on MMP and mitochondrial superoxide. Supplementation of Genistein promoted the secretion of E2 and increased the expression of Star and Cyp19a1 mRNA, whereas suppressed the level of progesterone (P4) accompanied with a decline in the level of Hsd3b1 mRNA expression. H89 blocked the regulation of Genistein on the secretion of E2 and P4, and alleviated the ascending of Star and Cyp19a1 elicited by Genistein. Collectively, Genistein protects GCs from OS via cAMP‐PKA signaling. |
