Objective: To investigate the possible effect targets of Celastrus orbiculatus extract (COE) in gastric cancer cells. Method: SGC-7901 cells were treated with different concentrations of COE for 24 and 48 h. The 50% concentration of inhibition (IC50) of COE was measured by 3-(4

5-dimethyl-2-thiazolyl)-2

5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Differentially expressed proteins were detected before and after COE treatment by using proteomic techniques. Partial protein expression was verified by Western blot. Result: COE inhibited the proliferation of SGC-7901 cells in a dose-and time-dependent manner. The IC50 in 24 h was 70.14 mg·L-1. The protein expression profile showed 13 differentiated expression protein spots after COE (70 mg·L-1) treatment on SGC-7901 cells for 24 h. Among the 13 proteins

9 proteins were down-regulated and 4 proteins were up-regulated. These proteins may be the action targets of COE in gastric cancer cells. Its effects on expression of heat shock protein 27 (HSP27)

prohibitin

cofilin-1

and annexin A5 were verified by Western blot

which were consistent with the proteomic results. Conclusion: COE has significant inhibitory effect on gastric cancer cells. The differentially expressed proteins provide new insights into the mechanisms involved in COE treatment for gastric cancer.