Abstract
4',5,6,7-tetrahydoxyisoflavone (6-hydroxygenistein, 6-OHG) is a hydroxylated derivative of genistein with excellent antioxidant activity, but whether 6-OHG can protect hypoxia-induced damage is unclear. The objective of current study was to evaluate the protective effect and underling mechanism of 6-OHG against hypoxia-induced injury via network pharmacology and cellular experiments. 6-OHG-related and hypoxia injury-related targets were screened by public databases. The intersected targets were used for constructing PPI network and performing GO and KEGG functional analysis. We induced injury in PC12 cells under hypoxia conditions and observed the effects and molecular mechanisms of 6-OHG on cellular damage. Network pharmacological analysis predicted that 6-OHG delayed hypoxia injury by mitigating oxidative stress, inflammatory response and apoptosis. Cellular experiments suggested that 6-OHG treatment mitigated cell damage, enhanced cell viability, reduced ROS production and MDA level, increased SOD and CAT activities and elevated GSH level in PC12 cell exposed to hypoxia. Additionally, 6-OHG treatment reduced the TNF-α and IL-6 levels and elevated the IL-10 content, while downregulated the NF-κB and TNF-α expressions. 6-OHG also inhibited the caspase-3 and - 9 activation and the Bax and cleaved caspase-3 expressions, and elevated the Bcl-2 expression. Moreover, 6-OHG remarkably enhanced Nrf2 nuclear translocation and increased HO-1 expression. Molecular docking also proved the strong binding affinities of 6-OHG with Nrf2 and HO-1. Furthermore, ML385, a specific Nrf2 inhibitor, eliminated the beneficial effects of 6-OHG. In summary, 6-OHG can alleviate hypoxia-induced injury in PC12 cells through activating Nrf2/HO-1 signaling pathway and may be developed as candidate for preventing neuro-damage induced by hypoxia.