Abstract: In this study,the PC12 cell damage model was induced by corticosterone,glutamic acid and hydrogen peroxide,respectively.The protective effect of different concentrations of water extracts of dry and fresh Panax ginseng on corticosterone-induced, glutamic acid-induced and hydrogen peroxide-induced damage in PC12 cells was determined by MTT and lactate dehydrogenase (LDH) assays.The results showed that the cell survival rates were 53.42%,49.64% and 54.27%,when PC12 cells were exposed to 200 μmol/L corticosterone, 30 mmol/L glutamic acid and 150 μmol/L hydrogen peroxide,respectively.When PC12 cells were incubated with different concentrations of water extract of P.ginseng for 24 h,then exposed to 200 μmol/L corticosterone and 150 μmol/L hydrogen peroxide,the cell survival rate was significantly increased compared with the model group,and the release of LDH was significantly reduced (P<0.01);the cell viability of fresh P.ginseng group was obvious higher than that of dry ginseng group (P<0.01).The LDH release amount of fresh P.ginseng group (both medium and high doses) was significantly lower than that of dry P.ginseng group (P<0.01).However,no protective effect in glutamic acid-induced injury model was detected.Water extracts of dry and fresh P.ginseng had apparent protective effect on corticosterone-induced and hydrogen peroxide-induced damage in PC12 cells;in the medium and high dose groups,cytoprotective activity of water extract of fresh P.ginseng was significantly better than that of dry P.ginseng group (P<0.01).All the above resultsed revealed that fresh P.ginseng had better cytoprotective activity than dry P.ginseng. Water extracts of dry and fresh P.ginseng had no protective effect on glutamate-induced injury in PC12 cells.

Key words: fresh ginseng, dry ginseng, PC12 cells, conticosterone, glutamic acid, hydrogen peroxide, MTT, LDH