Mitochondrial autophagy promotion contributes to the protective effects of BYHWD glycoside-enriched fraction against OGD/R-induced injury in H9C2 cells.

Myocardial ischemia-reperfusion injury is a major cause of mortality among patients with cardiovascular diseases and critically ill individuals. Its pathogenesis is complex and effective preventive or therapeutic strategies remain limited. Buyang Huanwu Decoction (BYHWD) is a classical Traditional Chinese Medicine formula used to tonify deficiency and promote blood circulation and is widely applied in the treatment of cardiovascular and cerebrovascular disorders. The total glycosides extracted from BYHWD, which mainly comprise astragaloside IV, paeoniflorin and amygdalin, represent its key bioactive components. Notably, the extract used is a glycoside-enriched fraction, in which astragaloside IV, paeoniflorin and amygdalin are the three major quantified components, rather than a pure mixture of these three compounds. In the present study, an H9C2 cell model of ischemia-reperfusion injury was established by 21 h of hypoxia followed by 6 h of reoxygenation to evaluate the cardioprotective effects of BYHWD glycosides. Autophagy and reactive oxygen species levels were analyzed by flow cytometry, while malondialdehyde and superoxide dismutase activities were measured using appropriate assay kits. Mitochondrial membrane potential changes were observed by fluorescence microscopy. The expression of PINK1 and Parkin pathway-associated proteins and genes was examined by western blotting and reverse transcription-quantitative PCR. Overall, BYHWD glycosides significantly reduced oxidative damage in H9C2 cells and protected cardiomyocytes from reperfusion injury, potentially by promoting mitochondrial autophagy. These protective effects may therefore be associated with regulation of the PINK1/Parkin-mediated mitochondrial autophagy pathway.