Contribution of ginsenoside Re to cellular redox homeostasis via upregulating glutathione and superoxide dismutase in HaCaT keratinocytes under normal conditions.

Ginsenoside Re (Re) is one of the main ginsenosides which are known to be responsible for diverse pharmacological properties of ginseng, widely used as a dietary supplement and a general tonic. The present work was undertaken to evaluate the antioxidative property of Re by analyzing reactive oxygen species (ROS), nitric oxide (NO), pro-matrix metalloproteinase-2 (proMMP-2) and -9 (proMMP-9), total glutathione (GSH) and superoxide dismutase (SOD) in normal, unstressed HaCaT keratinocytes. When HaCaT cells were subjected to Re, Re suppressed the ROS and NO levels in a concentration-dependent manner. Re at concentrations used exhibited no cytotoxicity on the cellular viabilities of HaCaT cells. It was also able to attenuate proMMP-2 and -9 at both activity and protein levels. On the contrary, Re was capable of enhancing the total GSH and SOD activity levels. The findings suggest that Re has an antioxidative property through the upregulation of some antioxidant components, including total GSH and SOD, in HaCaT keratinocytes, which then can play its underlying role in maintaining the cellular redox homeostasis.