Panax for obesity.
American ginseng or Panax quinquefolium is a North American native but has been used for years in traditional Chinese medicine to treat various conditions from psychiatric disorders to diabetes mellitus.
The herb's pharmacologically active constituents are known to be the glycoside ginsengosides, more specifically the saponins fractions [Rg.sub.1], Re, [Rb.sub.1], [Rg.sub.2], [Rb.sub.2], Rc and Rd. Over the years research has evinced a number of their activities including enhancement of cholesterol biosynthesis, anti-inflammatory and immune modulating effects, antioxidant and weight reduction properties.
In order to further investigate the weight reduction activity of the herb, a team of Chinese and Japanese scientists recently undertook a study on the isolated saponin fractions of P. quinquefolium. They set out to determine whether ginsengoside fractions [Rg.sub.1], Re, [Rg.sub.2], [Rb.sub.1], Rc, [Rb.sub.2], [Rb.sub.3] and Rd would inhibit lipase activity in vitro and prevent obesity in mice on a high fat diet.
In the in vitro research, crude saponins from the stem and leaves of the plant were used, and assay for their inhibitory effects on porcine pancreatic lipase was performed by measuring the rate of release of oleic acid from triolein. Results indicated a clear, strong inhibition of lipase activity, with ginsenosides [Rb.sub.1], [Rb.sub.2], Rc and Rd being the most active constituents.
In order to examine effects on blood lipid levels, the scientists dispensed the saponins (at 1g/kg body weight) to rats deprived overnight of food. When they administered the oral lipid emulsion tolerance test to these same animals, the rats receiving the herbal constituents showed much smaller elevations of plasma triacylglycerol than the control group (who were not on additional supplement-ation).
Finally the saponin fractions (at 1% or 3%) were administered to two groups of female ICR mice along with a high fat diet for eight weeks. A control group of mice was fed the same diet in the absence of Panax ginsengosides. Following this long term dosing the body weight of the mice in all three groups was similar, and energy intake was similar across the 8 weeks. However measurements of parametrial adipose tissue weight were decreased in the mice on a high fat diet containing 1% or 3% crude saponins compared to those in the high fat diet group.
The researchers conclude that the anti-obesity effects of Panax quinquefolium in high fat diet treated mice may be due to intestinal inhibition of dietary lipids by ginsengosides Rc, [Rb.sub.1] and [Rb.sub.2].
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|Publication:||Australian Journal of Medical Herbalism|
|Date:||Dec 22, 2008|
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