Abstract

Objectives: The present study investigated the anti-obesity activities of red ginseng acidic polysaccharide (RGAP) from Korean red ginseng (Panax ginseng C.A. Meyer) in high-fat diet (HFD)-induced mice.

Methods: Forty mice were divided randomly into four group (n=10, respectively): normal control (NC), high-fat-diet (HFD), HFD plus RGAP300mg/kg, HFD plus RGAP500mg/kg. The normal control was fed a normal diet and the other groups were fed an HFD. HFD mice were made obese by high-fat diet (35% fat) feeding for 6 weeks. The test mice were given red ginseng acidic polysaccharide orally at a single dose per day. Body weights of the mice were measured at weekly intervals. The effects of RGAP on obesity functions were assessed by measuring the serum lipid profiles and biomarkers of obesity. In addition, abdominal fat volumes were measured at the end of the experiment by using Micro X-ray CT.

Results: Mice in the HFD group showed an increase in body weight and food efficiency ratio, which means body weight gain per food intake. However, RGAP significantly reduced these values when compared with the normal control group. The RGAP group also showed significantly decreased epididymal fat mass. An increase in the serum levels of triglyceride and LDL/HDL ratio were observed in the HFD group, but RGAP administration reduced these serum levels. Serum levels of hepatic function markers such as AST and ALT, which were elevated by HFD-feeding, were also significantly reduced in the RGAP group. Levels of leptin, adiponectin, and lipoprotein lipase (LPL), which regulate glucose and lipid metabolism, were impaired by HFD. RGAP brought these levels back to near normal levels. In addition, it was confirmed by Micro X-ray CT that the abdominal fat masses increased by the HFD were reduced by RGAP.

Conclusion: This study showed that RGAP protected mice from obesity in the HFD-fed group. RGAP exerts anti-obesity effects in mice via the activation of lipoprotein lipase and improvement of leptin and adiponectin, which carry out critical functions in energy and lipid metabolism. These results suggest that red ginseng acidic polysaccharide might be a preventative functional food for these metabolic disorders.

Keywords: Panax ginseng C.A. Meyer; Red ginseng acidic polysaccharide; High-fat diet; Anti-obesity; Lipoprotein lipase; Abdominal fat mass; Micro X-ray CT

Abbreviations: HFD: High-Fat Diet; RGAP: Red Ginseng Acidic Polysaccharide; LDL: Low-Density Lipoprotein Cholesterol; HDL: High-Density Lipoprotein Cholesterol; AST: Aspartate Aminotransferase; ALT: Alanine Aminotransferase; LPL: Lipoprotein Lipase