Abstract: Objective: To study the effect of rhein on the proliferation and oxidative damage of human umbilical vein endothelial cells (HUVEC). Methods: An oxidative injury model was established with H2O2. HUVECs were incubated with rhein at various concentrations and the availability of rhein for protecting endothelial cells was explored. The release rate of lactic acid dehydrogenase (LDH), the contents of malondialdehyde (MDA) and NO, and the activities of nitrogen oxide synthase (NOS), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined. Flow cytometry was employed to investigate the apoptosis of HUVECs. Results: Rhein had no obvious effect on the proliferation of HUVECs when the concentration of rhein was less than 16 μmol/L. However, rhein at a concentration of more than 2 μmol/L could reveal significant protection against oxidative damage in HUVECs. The release rate of LDH and the content of MDA revealed an obvious decrease, whereas the content of NO and the activities of NOS, SOD and GSH-Px exhibited an obvious increase. The rates of apoptosis and necrosis were reduced significantly. Conclusion: Rhein can maintain the normal physiology of the cells and prevent the cells from H2O2-induced injury at a concentration of 2-16 μmol/L. It is particularly important for the prevention and treatment of atherosclerosis.

Key words: rhein, oxidative damage, endothelial cells, proliferation