Effects of in vitro-digested ginsenosides on lipid accumulation in 3T3-L1 adipocytes

Ginseng, the root of Panax ginseng C. A. Meyer, is frequently used in traditional oriental medicines. The major active components of ginseng are the saponins, which are also called ginsenosides and are known for their pharmacological and biological activities. In this study, the effects of ginsenosides on lipid accumulation in 3T3-L1 adipocytes were investigated after the ginsenosides were in vitro-digested with artificial gastric and intestinal fluids. Ginseng extract was incubated with an artificial digestive fluid, and the changes were analyzed by HPLC, after which the effects of the digest on 3T3-L1 adipocytes were observed. Polar ginsenosides were transformed into less-polar ginsenosides at the low pH of the gastric acid, without any influence from the digestive enzymes. Additionally, the artificially digested ginsenosides showed inhibitory effects on lipid accumulation in 3T3-L1 adipocytes. When the 3T3-L1 adipocytes were treated with various ginseng samples that possessed different polarities, the less polar ginsenosides were more effective in reducing lipid accumulation. Furthermore, when the Rg3, Rk1, and Rg5 ginsenosides were used to treat the cells individually, Rg3 ginsenoside was the most effective at inhibiting lipid accumulation. These results suggest that the less polar ginsenosides, particularly ginsenoside Rg3, effectively reduce lipid accumulation in adipocytes. Accordingly, our results suggest that ginsenoside Rg3 should be developed as an antiobesity treatment.