Effect of isoquercitrin on glutathione level. There are significantly higher glutathione in the control sample and significantly lower in samples incubated with 6-OHDA. The isoquercitrin pretreatment increased the glutathione level in 6-OHDA induced PC12 cells. Data are mean and S.E. values from three independent experiments (n = 3). #p < 0.05, relative to control cells. *p < 0.05, relative to cells treated only with 6-OHDA.