Antiobese and hypolipidemic effects of platycodin saponins in diet-induced obese rats: evidences for lipase inhibition and calorie intake restriction.

OBJECTIVE: To investigate how and to what extent platycodin saponin (PS) from Platycodi Radix exerts a favorable influence on obesity and hyperlipidemia. DESIGN: Sprague-Dawley rats were fed with a high fat (HF) diet for 4 weeks and then the animals were treated with 35 or 70 mg / kg of PS for another 4 weeks. Changes in body weight and daily calorie intake were measured regularly during the experimental period and the degree of linear correlation for the above two variables was further analyzed. The in vitro lipase inhibition of each PS compound and the in vivo fecal lipid excretion were examined in hope of revealing their relationship. The concentrations of hepatic triglyceride and cholesterol in serum. RESULTS: The body weight reduction (13+/-4% vs HF control, P<0.05) by PS administration was highly correlated to the food intake restriction (Pearson's linear coefficient r=0.752, P<0.005). The in vitro inhibition of lipase by each isolated compound and mixture of PS were virtually identical. Consequently, the fecal TG excretion was increased by 2.1-3.2 folds depending on the dose of PS. The serum TG and LDL-cholesterol concentrations were decreased without noticeable changes in HDL-cholesterol levels. Concomitantly, the contents of the hepatic TG, cholesterol, and the liver surface fat pads were decreased in ubiquity, but no noticeable biochemical abnormalities or histological tissue damages were observed. CONCLUSIONS: The administration of PS produced profound effects on the control of obesity and lipid metabolism, which resulted in LDL-cholesterol reduction. PS also caused a remarkable reduction in calorie intake, which was highly correlated to the body weight loss. These results suggest that PS has a greater role in anti-obesity, hypolipidemia, and liver protection than previously thought. Hence, PS could be a potential therapeutic alternative in the treatment of obesity and hyperlipidemia.

Some chemical and physical properties of extracellular polysaccharides produced by Butyrivibrio fibrisolvens strains.

Most strains of Butyrivibrio fibrisolvens are known to produce extracellular polysaccharides (EPs). However, the rheological and functional properties of these EPs have not been determined. Initially, 26 strains of Butyrivibrio were screened for EP yield and apparent viscosities of cell-free supernatants. Yields ranged from less than 1.0 to 16.3 mg per 100 mg of glucose added to the culture. Viscosities ranged from 0.71 to 5.44 mPa.s. Five strains (CF2d, CF3, CF3a, CE51, and H10b) were chosen for further screening. The apparent viscosity of the EP from each of these strains decreased by only 50 to 60% when the shear rate was increased from 20 to 1,000 s-1. Strain CE51 produced the EP having the highest solution viscosity. A detailed comparison of shear dependency of the EP from strain CF3 with xanthan gum showed that this EP was less shear sensitive than xanthan gum and, at a shear rate of 1,000 s-1, more viscous. EPs from strains CF3 and H10b were soluble over a wide range of pH (1 to 13) in 80% (vol/vol) ethanol-water or in 1% (wt/vol) salt solutions. The pH of 1% EP solutions was between 4.5 and 5.5. Addition of acid increased solution viscosities, whereas addition of base decreased viscosity. EPs from strains CF3, CE51, and H10b displayed qualitatively similar infrared spectra. Calcium and sodium were the most abundant minerals in the three EPs. The amounts of magnesium, calcium, and iron varied considerably among the EPs, but the potassium contents remained relatively constant.