Protective effects of quercetin against H2O2 induced KGN cells injury

Background: Oxidative stress is one of the key contributors to cellular senescence and ovarian aging. Quercetin has a variety of physiological activities such as antioxidant. Given that hydrogen peroxide can cause oxidative damage to cells, the present study is designed to verify the protective effect of quercetin on human ovarian granulosa tumor cell line under oxidative stress. Methods: Cell counting kit-8 and lactate dehydrogenase assays examined cell viability and toxicity. Flow cytometry detected reactive oxygen species accumulation. Glutathione level was measured to analyze the oxidation resistance. Cell apoptosis was evaluated by Hoechst 33258 staining, acridine orange/Ethidium Bromide staining and western blot. The mitochondrial structure was observed under a transmission electron microscope. Mitochondrial membrane integrity was detected by JC-1 staining and western blot. Results: Hydrogen peroxide could induce cell injury, promote reactive oxygen species accumulation, and lead to glutathione depletion. hydrogen peroxide also resulted in mitochondrial morphological damage and depolarization, which activate caspase3/9 subsequently. However, quercetin could mitigate these damages. Conclusions: Present study found that hydrogen peroxide induced oxidative stress and mitochondrial apoptosis of human ovarian granulosa tumor cell line cells, which could be attenuated by quercetin.