Objective: In this study

Human gastric cancer cell line SGC-7901 cells were used as a model and treated with the aqueous extract of actinidia chinensis medicated sera

to investigate the antioxidant mechanism via inducing the produce of phase 2 enzymes. Method: The normal SD rats were randomly divided into 4 groups: blank control group

high

middle and low dose groups. The actinidia chinensis aqueous extract was gavaged in different doses

respectively and water was gavaged in the blank control group and twice a day for 14 days. The blood was collected from abdominal aorta to prepare serum containing drugs

then which were given to the SGC-7901 cells separately at different time. Immunohistochemistry staining was used to detect the localization of nuclear factor-E2 related factor2 (Nrf2) in the SGC-7901cells

RT-PCR was used to detect the mRNA level of phase 2 enzymes. Result: The immunohistochemistry detecting showed that the expression of the nuclear Nrf2 was increased and the area broadened significantly(P<0.05) in th groups after administration with different doses of serum containing drugs in the SGC-7901 cells. The results of RT-PCR showed that the mRNA expression levels of the phase 2 enzymes glutamate cysteine ligase catalytic subunit (GCLC) were induced (P<0.05)

and the mRNA expression levels of glutathione-S-transferase (GST )- P1 and GST-T1 were enhanced significantly(P＜0.01)

which was no obvious effect on GST-M1 and heme oxygenase-1 (NQO1). Conclusion: The Actinidia chinensis aqueous extract can increase nuclear translocation of Nrf2 and increase the phase Ⅱ enzyme mRNA expression. The Actinidia chinensis aqueous extract has the function of antioxidant.