Protective effects of lipoic acid on cardiomyocytes undergoing hypoxia/reoxygenation injury

Objective To study the protective effect of lipoic acid (LA) on H9c2 cardiomyocytes hypoxia/reoxygenation injury model, and explore its relevant mechanism. Methods Eight strains of H9c2 cardiomyocytes, passaged after cultured to a full view, were divided into 3 groups: normoxia group, hypoxia/reoxygenation group and LA group. The cell survival rate, lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) and heme oxygenase-1 (HO-1) levels were detected and compared. Results The cell survival rates of H9c2 cardiomyocytes in hypoxia/reoxygenation group and LA group were significantly lower than those in normoxia group: (52.86 ± 6.39)%, (69.25 ± 7.63)% vs. (92.31 ± 7.82)%, while the cell survival rate of H9c2 cardiomyocytes in LA group was significantly higher than that in hypoxia/reoxygenation group, and there were statistical differences (P<0.01). The LDH activity and MDA in hypoxia/reoxygenation group and LA group were significantly higher than those in normoxia group: (286.37 ± 27.49), (209.72 ± 25.63) U/L vs. (126.32 ± 18.94) U/L, and (1.72 ± 0.06), (1.13 ± 0.07) μmol/L vs. (0.68 ± 0.06) μmol/L, while those data in LA group were significantly lower than those in hypoxia/reoxygenation group, and there were statistical differences (P<0.01). The HO-1 in hypoxia/reoxygenation group and LA group were significantly higher than that in normoxia group: (213.71 ± 18.94)%, (367.26 ± 23.07)% vs. (87.92 ± 19.23)%, and HO-1 in LA group was significantly higher than that in hypoxia/reoxygenation group, and there were statistical differences (P<0.01). Conclusions The LA plays a protective role on myocardial cell with hypoxia/reoxygenation injury though increasing the level of HO-1 against oxidative stress. Key words: Reperfusion injury; Thioctic acid; Myocytes, cardiac; Oxidative stress