Protective Effects of Melatonin on Human Umbilical Vein Endothelial Cell Injury Induced by LPS

Objective: To investigate the protective effect of melatonin(MLT) on human umbilical vein endothelial cells(HUVECs) injury and their preliminary mechanism.Methods: Lipopolysaccharide(LPS) was used to injure HUVECs in vitro.The cultured HUVECs were treated with MLT(200 μmol/L,400 μmol/L,600 μmol/L) for 8 h,and the survival ratio of HUVECs was detected with MTT assay.The cultured cells were loaded by Fura-2/AM and the change of [Ca2+] in HUVECs was measured by fluorospectrophotometry.The contents of malondialdehyde(MDA),superoxide dismutase(SOD),reduced glutathione(GSH-Px) were measured by the commercial kits.The levels of tissue plasminogen activator IL-6 in the supematant were measured by enzyme linked immunosorbent assay(ELISA) kits.Apoptosis rate of the HUVECs was analyzed by flow cytometry.Results: LPS significantly increased the contents of MDA,IL-6 while decreased HUVECs viability,the contents of SOD and GSH-Px,and meantime increased the apoptosis rate about 38.9±1.1% expression in the injured groups.MLT at different dosages could depress the content of MDA and IL-6,improve the activity of SOD and GSH-Px compared with that in injury control group,both of which were depended on the concentration of MLT.Conclusions: The findings demonstrate that MLT displayed a protective action on LPS induced injury in human umbilical vein endothelial cells.Its effect may be related with the protection to cell chondriosome improvement in the antioxygenic activity of cells,and with suppressing the mobilization of cytosolic calcium.