Ginseng (Panax quinquefolius) Reduces Cell Growth, Lipid Acquisition and Increases Adiponectin Expression in 3T3-L1 Cells

An American ginseng (Panax quinquefolius) extract (GE) that contained a quantifiable amount of ginsenosides was investigated for the potential to inhibit proliferation, affect the cell cycle, influence lipid acquisition and adiponectin expression in 3T3-L1 cells. Six fingerprint ginsenosides were quantified by high performance liquid chromatography and the respective molecular weights were confirmed by LC-ESI-MS analysis. The extract contained Rg1 (347.3 +/- 99.7 mu g g(-1), dry weight), Re (8280.4 +/- 792.3 mu g g(-1)), Rb1 (1585.8 +/- 86.8 mu g g(-1)), Rc (32.9 +/- 8 mu g g(-1)), Rb2 (62.6 +/- 10.6 mu g g(-1)) and Rd (90.4 +/- 3.2 mu g g(-1)). The GE had a dose-dependent effect on 3T3-L1 cell growth, the LC50 value was determined to be 40.3 +/- 5 mu g ml(-1). Cell cycle analysis showed modest changes in the cell cycle. No significant changes observed in both G1 and G2/M phases, however there was a significant decrease (P < .05) in the S phase after 24 and 48 h treatment. Apoptotic cells were modest but significantly (P < .05) increased after 48 h (3.2 +/- 1.0%) compared to untreated control cells (1.5 +/- 0.1%). Lipid acquisition was significantly reduced (P < .05) by 13 and 22% when treated at concentrations of 20.2 and 40.3 mu g ml(-1) compared to untreated control cells. In relation to adiponectin activation, western blot analysis showed that the protein expression was significantly (P < .05) increased at concentrations tested. A quantified GE reduced the growth of 3T3-L1 cells, down-regulated the accumulation of lipid and up-regulated the expression of adiponectin in the 3T3-L1 adipocyte cell model.