Anti-obesity activities of Korean red ginseng saponin fraction (RGS) and/or Glycyrrhiza glabra L. extract (GG) were investigated in 3T3-L1 adipocytes and high-fat diet-induced C57BL/6J obese mice. RGS and GG extracts were mixed at a mass ratio of 3:1 (SG31), 1:1 (SG11), or 1:3 (SG13). SG31 showed the highest anti-obesity activity among the three different mass ratios of RGS and GG extracts. SG31 showed higher inhibition efficiency on triglyceride (TG) accumulation than either single extract in 3T3-L1 adipocytes and without any cytotoxicity. It also decreases the expression of adipogenic and lipogenic genes such as C/EBPα and SREBP-1c (sterol regulatory element-binding protein 1c). In the obese induced mouse model, SG31 significantly reduced white adipose tissue weight and body weight, attenuated dyslipidemia, and decreased serum TG levels. In some indices, the activity of SG31 was even higher compared with Garcinia Cambogia water extract, a positive control. The possible mechanism by which SG31 causes the above results was by activating the AMP-activated protein kinase (AMPK) pathway and stimulating the secretion of adiponectin in adipose tissue to regulate energy metabolism balance, inhibit TG formation, and promote β-oxidation of fatty acids. Therefore, SG31 may have efficacy as an anti-obesity functional food or raw material if the results can be confirmed in human studies.
Keywords: AMPK pathway; additive effect; extract mixture; obesity; transcription factor.