Ginseng saponins 20(S)-ginsenoside Rg(2) extracted from cultured Panax notoginseng cells in a fermenter show a protection effect on human umbilical cord vein endothelial cells (VEC-304) from H2O2-induced cell apoptosis. When 50 mu g/ml 20(S)-ginsenoside Rg(2) was present in the culture medium for 8 h, the H2O2-damaged VEC-304 cells acquired about 11-fold (p < 0.01) on the amount and about 2-fold (p < 0.05) increase in PA activity compared with those untreated cells. And the Rg(2) has a strong ability in scavenging intracellular ROS induced by H2O2. (c) 2005 Published by Elsevier Ltd.