OBJECTIVETo evaluate the antitumor effect of total saponins of R. parvifolius on malignant melanoma.

METHODThe human malignant melanoma A375 cells were regularlly subcultured in vitro, and were divided into five groups contained positive control group (CTX), high concentration (0.01 mg x mL(-1)) and middle concentration (0.001 mg x mL(-1)) and low concentration (0.000 1 mg x mL(-1)) total saponins of R. parvifolius groups and negative control group. By using MTT colorimetric method, the cell viability was measured. B16 melanoma cells were transplanted to mice, which were divided into positive control group, high dose (100 mg x kg(-1)) and middle dose (50 mg x kg(-1)) and low dose (25 mg x kg(-1)) total saponins of R. parvifolius groups and negative control group. The inhibition effect of the tumor in vivo, mean survival time and rate of life-elongation of the mice were observed. TUNEL method was used to detect the apoptosis of B16 malignant melanoma.

RESULTAntitumor assay in vitro showed that the absorbency increased in the concentration of 0.01, 0.001 mg x mL(-1) with statistical significance (P < 0.05 vs negative control). Antitumor assay in vivo showed that the tumor inhibitory rate of high dose (100 mg x kg(-1)) and middle dose (50 mg x kg(-1)) of total saponins of R. parvifolius were 37.02% and 30.61%, respectively. Loaded tumor mouse survival duration could be prolonged. The apoptosis indexes of B16 tumor cells in three treatment groups were 32.5%, 20.5% and 5.5%, respective and there was statistical significance (P < 0.05 vs negative control).

CONCLUSIONThe total saponins of R. parvifolius has remarkable inhibition of proliferation of malignant melanoma cells in vivo and in vitro and exerts antitumor activities through promoting tumor cell apoptosis.