Effect of petroleum ether extract of Panax ginseng roots on proliferation and cell cycle progression of human renal cell carcinoma cells

Panax ginseng roots have long been used as a medicinal herb in oriental countries. We have investigated anti-proliferative effects of lipid soluble Panax ginseng components on human renal cancer cell lines. Petroleum ether extract of Panax ginseng roots (GX-PE) or its partially purified preparation (7:3 GX) was added to cultures of three human renal cell carcinoma (RCC) cell lines, A498, Caki-1, and CURC II. Proliferation of RCC cells was estimated by a [3H]thymidine incorporation assay and cell cycle distribution was analyzed by flow cytometry. GX-PE, 7:3 GX, panaxydol and panaxynol inhibited proliferation of all three RCC cell lines in a dose dependent manner in vitro with an order of potency, 7:3 GX > panaxydol > panaxynol = GX-PE. Additive effect of interleukin 4 was also demonstrated, most prominently in Caki-1 which responded poorly to GX-PE alone. Analysis of cell cycle in CURC II and Caki-1 treated with GX-PE demonstrated increase in G1 phase population and corresponding decrease in S phase population. The present study demonstrated that proliferation of human RCC cell lines were inhibited by lipid soluble components of Panax ginseng roots by blocking cell cycle progression at G1 to S phase transition.

Effects of Lipid Soluble Components of Korean Red Ginseng on Proliferation and Cell Cycle Regulation Factors in Human Melanoma Cell Lines / 대한암학회지

PURPOSE: Growth inhibitory effects of lipid soluble components of the Korean red ginseng and the antineoplastic mechanism against human melanoma cell lines were investigated. To examine molecular mechanism of growth inhibitory effects of GX-PE, we analyzed the effect of GX-PE on cell cycle progression and expression of cell cycle regulatory factors such as retinoblastoma gene product (Rb), p27 (Kip1), p21 (WAF1), cdk2, cdk4 and cyclin D1 which are known to regulate cell cycle progression. MATERIALS AND METHODS: Petroleum ether extract of the Korean red ginseng (GX-PE) was added to cultures of three human melanoma cell lines, SK-MEL-1, SK-MEL-2, and SK-MEL-5. Proliferation was measured by 3H-thymidine incorporation assay. Cell cycle and expression of cell cycle regulatory factors were analyzed by flow cytometry and Western blotting, respectively. RESULTS: Growth of melanoma cells was inhibited by GX-PE in proportion to the concentration. GX-PE significantly inhibited cell cycle progression at G1 phase. GX-PE increased expression of negative cell cycle regulators, i.e., p27 (Kip1) in SK-MEL-2 and p21 (WAF1) and Rb in SK-MEL-1. CONCLUSION: These results suggest that GX-PE inhibits proliferation of melanoma cells at a G1-S transition point of the cell cycle. The effect of GX-PE is most likely due to induction of negative cell cycle regulatory factors.