Hypocholesterolemic and anti-obesity effects of saponins from Platycodon grandiflorum in hamsters fed atherogenic diets

Platycodins, a group of saponin glycosides from Platycodon grandiflorum, are believed to possess anti-obesity and cholesterol-lowering properties. The aim of the present study was to investigate whether dietary platycodins affect plasma, hepatic, or fecal cholesterol concentrations, as well as cholesterol absorption and fractional synthesis rates in a dose-dependent manner. Golden Syrian hamsters (n= 45) were fed atherogenic (0.25% cholesterol) diets enriched with platycodins in the forms of either aqueous extracts (containing 0.3% to 0.5% of platycodins of diet mass) or crude saponins fractions (containing 0.9% to 1.0% of platycodins of diet mass) for 28 d. [3, 4](-13)C-cholesterol and (2)H2O tracers were administered on days 26 and 28 to assess cholesterol absorption and biosynthesis, respectively. After platycodin intervention, total cholesterol concentrations in plasma and liver were reduced (P <0.05) by 13% to 28% and 41% to 79%, respectively, whereas cholesterol concentrations in feces were increased (P <0.05) up to 2.5-fold compared to controls. Platycodin feeding increased (P <0.001) cholesterol absorption up to 60%, but not cholesterol synthesis. These results suggest that platycodin-enriched diets can lower circulating and whole body cholesterol contents, and thus reduce the risk of cardiovascular diseases through mechanisms independent from cholesterol absorption or synthesis.