Puerarin protects cardiomyocytes from ischemia–reperfusion injury by upregulating LncRNA ANRIL and inhibiting autophagy

This study analyzed the roles of puerarin and LncRNA ANRIL in myocardial ischemia-reperfusion injury. Hypoxia/reperfusion (H/R) model was established with H9C2 cells. Effects of puerarin of gradient concentrations on cardiomyocytes at different time points of hypoxia and reoxygenation were detected by quantitative real-time polymerase chain reaction (qRT-PCR), cell counting kit-8 (CCK-8), and microscope observation. Effects of puerarin on cardiomyocyte viability, ANRIL expression, contents of lactate dehydrogenase (LDH) and malondialdehyde (MDA), apoptosis, and expressions of autophagy-related genes after H/R injury were determined by CCK-8, quantitative real-time polymerase chain reaction (qRT-PCR), ELISA, flow cytometry, and Western blot, respectively. After cell transfection, the effects of overexpressed and knockdown of ANRIL on cardiomyocytes and H/R-injured cardiomyocytes were examined by rescue experiments. The ischemia-reperfusion (I/R)-injured rat model was established to examine the protective effect of puerarin in vivo. Prolonged hypoxia downregulated ANRIL expression in cardiomyocytes and reduced cardiomyocyte viability. Prolonged reoxygenation increased apoptosis. Both cardiomyocyte viability and ANRIL expression showed a dose-dependent relationship with puerarin. Puerarin reversed the effects of H/R injury on cardiomyocyte viability, ANRIL expression, contents of LDH and MDA, apoptosis, and expressions of autophagy-related genes. Overexpression and knockdown of ANRIL regulated the functions of cardiomyocytes and the expressions of autophagy-related genes. Puerarin reversed the effects of knockdown of ANRIL on H/R-injured cells. The results of In vivo experiments confirmed that puerarin protected myocardial tissues by up-regulating ANRIL and inhibiting autophagy.