摘要：The ability of curcumin, a natural antioxidant isolated from Curcuma longa , to inhibit hydrogen peroxide (H2O2)-induced cell damage in NG108-15 cells was examined. When added simultaneously with 500 μ M H2O2, curcumin (25—100 μ M ) effectively protected cells from oxidative damage. However, when the cells were pretreated with curcumin (25—100 μ M ) for 1.5 h before H2O2 exposure, curcumin was unable to inhibit H2O2-induced cell damage. Instead, it caused a significant concentration-dependent decrease in cell viability after H2O2 exposure. This dual action of curcumin suggests that pretreatment with curcumin by itself did not have any significant effect on the viability of the NG108-15 cells, but it sensitized them to oxidative damage induced by H2O2 under our experimental conditions. It appears that these events may not relate to the antioxidant and free radical scavenging activities of curcumin.
