OBJECTIVE: To observe toxicity-reduced effects of Leigongteng(Radix et Rhizoma Tripterygii)(LGT) via compatibility with Jinqiancao(Herba Lysimachiae)(JQC) in H22-bearing mice and investigate the possible underlying mechanism, and further explore whether JQC can enhance LGT-evoked anti-tumor effect.METHODS: H22-bearing mice were orally administered with LGT alone and its compatibility with JQC, and tumors, serum, livers and kidneys were collected to evaluate the toxicity-reduced efficacy and the possible mechanism.RESULTS: LGT evoked significantly elevated biochemical indicators including serum alanine/aspartate transaminase(ALT/AST), creatinine(Cr) and urea nitrogen(BUN) as well as pathological damage in mice, which were all obviously reversed by JQC via compatibility at the ratios from 4/1 to 1/4.Further analysis indicated that pro-inflammatory cytokine tumor necrosis factor-alpha(TNF-α), and malondialdehyde(MDA) levels significantly decreased, while anti-inflammatory cytokine interleukin(IL)-10, and glutathione(GSH), GSH-s transferase(GST), GSH peroxidase(GSH-Px), superoxide dismutase(SOD) and catalase(CAT) levels all increased in livers and kidneys of mice. Besides, after compatibility with JQC at the ratios of 4/1, 2/1, 1/1,1/2 and 1/4, LGT-decreased tumor weight was further decreased by 48.4%, 57.3%, 54.0%, 49.3% and52.9%, respectively(all P < 0.01).CONCLUSION: JQC could reduce LGT-induced hepatotoxicity and nephrotoxicity, and enhance the antitumor efficacy via compatibility with JQC, and the toxicity-reduced mechanism could involve inhibiting hepatic and kidney oxidative stress and inflammation.