OBJECTIVE:To investigate the efficacy of the ex-tract from Yiyuan Yiliu Tang(益元抑瘤汤,YYYLT)on human lung adenocarcinoma cells A549 and hu-man hepatoma cells Bel7402.METHODS:The cancer cell lines were treated with various concentrations(0,100,200,300,and 400 μg/mL)of the crude water extract of YYYLT and then cell viability,toxicity,cytokine secretion,and cell cycle/apoptosis were determined by MTT assay,LDH assay,and flow cytometry,respectively.RESULTS:The extract from YYYLT significantly sup-pressed the proliferation of the cancer cell lines and the release of interleukin-2 and tumor necrosis factor-α in a dose-dependent manner.The extract also promoted apoptosis,caused cell cycle arrest at G0/G1 phase,and increased the expression of cas-pase-3,B-cell lymphoma-2(Bcl-2),and Bcl-2-associ-ated X proteins.CONCLUSION:The extract from YYYLT might be a potential treatment for human lung and liver cancers.