OBJECTIVETo investigate the effects of a Chinese herbal extract Songyou Yin on residual hepatocellular carcinoma after chemotherapy in nude mice and the relevant mechanisms.

METHODSOrthotopic nude mouse models bearing residual hepatocellular carcinoma after chemotherapy was established using human liver carcinoma MHCC97L cells. Three different doses of Songyon Yin (2.1 g/kg, 4.2 g/kg and 8.4 g/kg) were administered to the mice in the trial groups by intragastric gavage, respectively. The mice in the control group were administered physiological saline. The tumor growth, metastasis and survival in the mice of each group were recorded. The corresponding mechanisms were studied.

RESULTSThe pulmonary metastasis rates of the control group and 2.1g/kg, 4.2g/kg, 8.4g/kg Songyou Yin treatment group were 86.7%, 73.3%, 40.0%, and 20.0%, respectively, and the survivals of these groups were 53.83 ± 4.71, 56.50 ± 6.09, 66.67 ± 5.61, 81.17 ± 7.36 days, respectively. Compared with the mice in the control group, mice in the 4.2 g/kg, 8.4 g/kg Songyou Yin treatment groups had a lower pulmonary metastasis rate (P = 0.021 and P = 0.001, respectively) and longer survival (P = 0.002 and P = 0.001, respectively). A restoration of E-cadherin expression and a concomitant reduction of N-cadherin expression were detected in the tumors of the 4.2 g/kg and 8.4 g/kg Songyou Yin treatment groups.

CONCLUSIONSSongyou Yin effectively inhibits the invasion and metastasis of the residual hepatocellular carcinoma after chemotherapy in nude mice through attenuating the epithelia-mesenchymal transition and prolongs the survival. Songyon Yin may have potential to promote the efficacy of chemotherapy in hepatocellular carcinoma.