Suppression of cholesterogenesis and reduction of LDL cholesterol by dietary ginseng and its fractions in chicken liver

Abstract

The effects of ginseng root powder and of serially extracted solvent fractions of ginseng on avian hepatic cholesterol metabolism and lipogenesis and on avian serum lipoprotein cholesterol levels were examined. In one study, White Leghorn females were fed for 4 weeks a corn-based diet (control) or an experimental diet in which was incorporated 0.25% Wisconsin ginseng or an equivalent quantity of a serial solvent fraction [petroleum ether (PESF), methyl alcohol (MESF), water (WASF)] or of the residue. beta-hydroxy-beta-methylglutaryl-CoA (HMG-CoA) reductase activity was significantly lower (P less than 0.01) in each of the treatment groups (31-37% of control activity) except that fed the extracted residue (90% of control, N.S.). Cholesterol 7 alpha-hydroxylase activity was lowered in parallel (45-64% of control, P less than 0.01) by all treatments except the residue (100% of control). Also with the exception of the residue treatment, each ginseng treatment effected a lowering of the serum total cholesterol level (67-83% of control, P less than 0.01) and of serum low density lipoprotein cholesterol level (53-81% of control, P less than 0.01). Lipogenic activities and serum triglycerides levels were lowered (P less than 0.01) by two of the ginseng treatments. The PESF treatment was the most effective suppressor of each parameter, 74% and 68% respectively, of the control values. The WASF also had significant impact. Not one of the experimental diets influenced the serum high density lipoprotein level. The PESF, the potent source of suppressors, effected a change in the ratio of low to high density lipoprotein cholesterol from 1.46 (control) to 0.88. The levels of cholesterol and triglycerides in liver under these conditions showed a similar pattern as that of serum. In companion studies, broiler females were fed 0.28% Chinese red ginseng root powder or its various fractions. The results confirmed those recorded above. The factor(s) responsible for lowering the serum total and low density lipoprotein cholesterol levels were generally more concentrated in the PESF and WASF of ginseng and each was significantly more effective than was ginseng root powder. Ginsenosides (saponins) are considered to be the active agents for the suppression of cholesterogenesis and lipogenesis.