Protective effects of curcumin on vascular endothelial injuries induced by radiation

Objective To study the effects of curcumin on vascular endothelial injuries induced by radiation and the mechanism.Methods Human umbilical vein endothelial cells (HUVEC) were isolated,cultured and divided into the control group and 4 groups exposed to 3-ray at the doses of 2,4,6 and 8 Gy.Cellular morphological and ultrastructural changes were examined under light microscopy and electron microscopy respectively.Flow cytometry was used to detect the cellular apoptosis,necrosis and intracellular reactive oxygen species (ROS) generation.The contents of Lactate dehydrogenase (LDH) and malondialdehyde (MDA) in the cultures were measured before and after irradiation.Results The results of cellular morphological and ultrastructural examinations shown that the typical apoptotic changes appeared after irradiation.The rates of apoptosis and necrosis in groups pretreated with curcumin were significantly lower than those in other groups (P＜0.05).LDH and MDA in the irradiation groups were significantly higher than those in curcumin pretreatment groups (P＜0.05).The ROS generation in radiation groups significantly increased with the radiation doses,as compared with the groups pretreated with curcumin (P＜0.05).Conclusion Irradiation induced the apoptosis and necrosis of HUVEC,and increased significantly the intracellular LDH and MDA levels in a dose-dependent.Curcumin had the protective effects on HUVEC from the apoptosis and necrosis induced by radiation. Key words: Vascular endothelial cells;  Radiation damage;  Apoptosis;  Intracellular reactive oxygen species