[Differentiation of B16 melanoma cells induced by ginsenoside RH2]

The effect of ginsenoside Rh2, a constituent isolated from Panax ginseng C. A. Meyer, on the growth of tumor cells in vitro was investigated. The results showed that Rh2 inhibited the growth of B16 cells at the concentration of 10 micrograms.ml-1 (IC50: 4.1 micrograms.ml-1). Rh2 was found to significantly induce the activity of differentiation of B16 cells at the concentration of 10 micrograms.ml-1 in vitro. The melanin synthesis of Rh2 in treated B16 cells was increased. Morphologically, the Rh2 induced B16 cells turned to be epithelioid cells. B16 cells became dendrite shaped morphologically at higher concentration of Rh2. Flow cytometry demonstrated that the B16 cells treated with Rh2 were blocked at G1 phase.