Platycodon grandiflorum Extract Reduces High-Fat Diet-Induced Obesity Through Regulation of Adipogenesis and Lipogenesis Pathways in Mice

Abstract

Obesity is caused by an energy imbalance between food intake and energy expenditure, and has detrimental effects on human health. Platycodon (Platycodon grandiflorum) widely grows in Korea, Japan, and China. It has long been used for food and as a medicinal product. However, the mechanism of the improvement of obesity by platycodon was still not clear. Therefore, we investigated the detailed mechanisms of the antiobesity activity of platycodon extracts. Twenty mice (C57BL/6J) were placed into five groups. The test group received 1 g/kg platycodon extracts. The positive control group received 10 mg/kg orlistat, while the negative control and normal control groups received phosphate-buffered saline. The extracts were given orally daily for 8 weeks. The in vivo treatment of platycodon extracts reduced body weight gain by 7.5%, improved plasma lipid profiles. In the groups given platycodon extracts, leptin was significantly decreased whereas adiponectin was increased. Furthermore, platycodon extracts downregulated lipogenic gene (e.g., lipoprotein lipase, acetyl-CoA carboxylase, and fatty acid synthase) expression and increased lipolysis genes (e.g., carnitine palmitoyltransferase 1 alpha, hormone-sensitive lipase, and uncoupling proteins 2) in liver and white adipose tissue. In addition, platycodon extracts inhibited the expression of key adipogenic transcriptional factors. In conclusion, we have demonstrated that platycodon extracts ameliorate high-fat diet-induced obesity and its related metabolic disease by regulating multiple pathways. Dietary supplementation of platycodon extracts as a functional food and medicinal ingredients may be suitable for prevention and treatment of obesity.