Objective: To evaluate the effects of Zuozhu Daxi on rats with chronic atrophic gastritis (CAG)caused by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG). Method: CAG model was established by drinking 170 mg·L-1 MNNG for 8 weeks. Then the model rats were randomly divided into 5 groups

which was administered with distilled water(10 mL·kg-1·d-1)

Moluodan(0.36 g·kg-1·d-1)

Zuozhu Daxi (0.4

0.2

0.1 g·kg-1·d-1). At the end

the pathologic changes of gastric mucosa were observed

and malondialdehyde (MDA)

superoxide dismutase(SOD)

interleukin 12(IL-12)

nitric oxide(NO)in serum were tested. Result: Compared with the control group

the IL-12 of model group were decreased significantly(P<0.01).Compared with the model group

IL-12 levels in large and middle doses of Zuozhu Daxi were increased significantly (P<0.05

P<0.01)

the amount of NO and MDA was reduced significantly(P<0.05

P<0.01). SOD had no significant difference between groups. The stomach tissue sections stained by HE showed that the relief of pathological changes of gastric mucosa in the treatment groups were much better than model group. Conclusion: Zuozhu Daxi has therapeutic effect on rats with chronic atrophic gastritis caused by MNNG.