Protecctive effect and mechanism of mafnesium lithospermate B on hypoxia/reoxygenation-induced apoptosis in cardiac microvascular endothelial cells

Abstract

Objective To investigate the role and possible mechanism of mafnesium lithospermate B (MLB) on hypoxia/reoxygenation-induced apoptosis of cardiac microvascular endothelial cells (CMECs). Methods CMECs of rat were cultured in vitro and the model of hypoxia/reoxygenation (H/R) was established. MLB with four concentrations (12.5, 25, 50, 62.5 μmol/L) was selected. TdT-mediated dUTP nick-end labeling (TUNEL) method was used to detect apoptosis index of CMECs, and determine the optimum concentration of MLB with lowest rate of apoptosis. Then CMECs were randomly divided into normal control group, H/R group, H/R + MLB group and H/R+ MLB+ Zn-protoporphyrin IX (ZnPPIX) group. Cell migration ability was detected by transwell method and the apoptosis index was measured by flow cytometry. Results Compared with H/R group, different concentrations of MLB can inhibit apoptosis of CMECs in a dose-dependent menner, and there was a significant protective effect in 50 μmol/LMLB group (P<0.01). After the intervention of ZnPPIX, the cell migration ability was significantly decreased (P<0.05), and the apoptosis index was significantly increased (P<0.01). Conclusions MLB can reduce apoptosis of CMECs induced by hypoxia/reoxygenation. Its mechanism may be related to the increase of heme oxygenase level. Key words: Apoptosis; Mafnesium lithospermate B; Cardiac microvascular endothelial cells; Hypoxia/reoxygenation; Heme oxygenase