Anti-obesity Effects and Mechanisms of American Ginseng and Its Ginsenosides in Pre-adipocytes and Obese Mice
American ginseng (Panax quinquefolius), the fifth most commonly used natural product in US, has opposite medical effects with Asian ginseng (Panax ginseng C.A. Meyer) according to the theory of traditional Chinese medicine. While the Asian ginseng anti-obesity effect has been extensively investigated recently, there are very limited data about American ginseng on obesity, the number one public health issue in US. In the present study, we screened the major ginsenosides of American ginseng and compared the anti-adipogenic effect between American ginseng root extract (AME) and Asian ginseng root extract (ASE) using the pre-adipocyte differentiation assay. AME and the selected ginsenosides compound K (CoK), Rg3 and Rh2 were further investigated in 3T3-L1 cells, human primary pre-adipocytes (HPAs) and obese mice. Our results show that ginsenosides Rg3, Rh2 and CoK, but not Rb1, Rb2, Rb3, Rc, Rd, Re and Rf inhibited intracellular lipid droplets at 50 μM in 3T3-L1 cells. We found for the first time that ASE is more powerful in inhibiting cell differentiation than that of AME at the selected concentrations. AME, CoK, Rg3 and Rh2 dose-dependently attenuated cell differentiation in 3T3-L1 cells and/or HPAs, which is companied by the attenuation of the expressions of adipogenic markers including peroxisome proliferator-activated receptor gamma (PPAR-γ), CCAAT/enhancer binding protein alpha (C/EBP-α), fatty acid synthase (FAS), fatty acid binding protein 4 (FABP4) and/or perilipin. Comparing to 3T3-L1cells, we are the first found that HPAs are more sensitive in reducing fat accumulation by AME, CoK and Rg3. Although dietary intake of AME (0.1%, 0.5%, 1mg, 5 mg AME/kg diet, 8 weeks) and selected ginsenoside CoK, Rg3 and Rh2 (0.1mg /kg diet, 8 weeks) did not significantly reduce body weight gain, food intake and fat pads, PPAR-γ protein expression in liver, fasting blood glucose and hepatic glutathione reductase and glutathione S-transferase, two major antioxidants molecules were significantly reduced by Rg3, Rh2, AME and CoK at the end of the experiment. These results suggest that AME may be a potential agent in reducing/preventing obesity in humans although more studies are needed.
"Anti-obesity Effects and Mechanisms of American Ginseng and Its Ginsenosides in Pre-adipocytes and Obese Mice"
ETD Collection for Tennessee State University.