Gypenosides attenuate cholesterol-induced DNA damage by inhibiting the production of reactive oxygen species in human umbilical vein endothelial cells

Abstract

Previous studies have demonstrated that DNA damage induces atherosclerosis and that oxidative stress has an important role in DNA damage. Gypenosides (Gps), the main ingredient of Gynostemma Pentaphylla (Thunb.) Makino, have been recognized as specific antioxidants and have previously been reported to inhibit high-fat diet-induced atherosclerosis in rats. However, whether or not Gps attenuate DNA damage through their antioxidant effects remains to be elucidated. The current study was performed to clarify whether or not Gps can inhibit cholesterol-induced DNA damage through antioxidation. The present study provided new insights into the pharmacological effects of Gps on atherosclerosis. HUVECs were treated with Gps at various concentrations (1, 10 and 100 μg/ml) for 1 h. The protective effects of Gps on cholesterol-induced DNA damage were determined using immunofluorescence, western blotting, reverse-transcription quantitative polymerase chain reaction and flow cytometry. Pretreatment with Gps (1, 10 and 100 μg/ml) effectively attenuated cholesterol-induced DNA damage in HUVECs by inhibiting phosphorylation of H2AX, a member of the histone family. Furthermore, Gps (100 μg/ml) pretreat-ment inhibited cholesterol-induced transcription and activity of nicotinamide adenine dinucleotide phosphate-oxidase 4 and reduced intracellular ROS levels. In conclusion, Gps attenuated cholesterol-induced DNA damage by inhibiting ROS production in HUVECs, suggesting that the inhibitory effect of Gps on atherogenesis is correlated with the alleviation of DNA damage.