Vitamin C increases the fecal fat excretion by chitosan in guinea-pigs, thereby reducing body weight gain.

The aims of this study were to investigate the antiobesity properties of chitosan on its own, as well as in the presence of vitamin C, in vivo. Hartley guinea-pigs were divided into Control (normal diet), F-control (high fat diet), Chitosan (high fat diet with 5.0% chitosan) and Chito-vit C (high fat diet with 5.0% chitosan containing 0.5% vitamin C) groups, respectively. The effects of chitosan, both alone and in the presence of vitamin C, on body weight, total fecal weight, fecal composition and plasma lipid level were studied for 5 weeks. The results of this study indicated that the fat-binding and water-holding capacity of chitosan might decrease body weight by reducing the absorption of cholesterol and fat, subsequently increasing total fecal weight, fecal fat excretion and fecal water excretion. Vitamin C increased the fecal fat excretion by chitosan in guinea-pigs, thereby reducing body weight gain.

Appetite suppressive effects of yeast hydrolysate on nitric oxide synthase (NOS) expression and vasoactive intestinal peptide (VIP) immunoreactivity in hypothalamus.

To investigate the effects of yeast hydrolysate on appetite regulation mechanisms in the central nervous system, nitric oxide synthase (NOS) expression and vasoactive intestinal peptide (VIP) immunoreactivity in the paraventricular nucleus (PVN) and ventromedial hypothalamic nucleus (VMH) of the hypothalamus were examined. Male Sprague-Dawley (SD) rats were assigned to five groups: control (normal diet), BY-1 and BY-2 (normal diet with oral administration of 0.1 g and 1.0 g of yeast hydrolysate <10 kDa/kg body weight, respectively), AY-1 and AY-2 (normal diet with oral administration of 0.1 g and 1.0 g of yeast hydrolysate 10-30 kDa/kg body weight, respectively). The body weight gain in the BY groups was less than that in the control. In particular, the weight gain of the BY-2 group (133.0 +/- 5.1 g) was significantly lower (p < 0.05) than that of the control group (150.1 +/- 3.7 g). Among the test groups, the BY-2 group was shown to have significantly lower triacylglycerol (TG) levels (p < 0.05) than the other groups. The staining intensities and optical densities of NOS neurons in the PVN of the AY group were significantly higher (p < 0.05) than in the control and BY groups. The staining intensities and optical densities of VIP immunoreactivity in the PVN and VMH of the BY groups were higher than those of the AY groups and the control. In conclusion, these results indicated that yeast hydrolysate of <10 kDa reduced the body weight gain and body fat in normal diet-fed rats and increased the lipid energy metabolism by altering the expression of NOS and VIP in neurons.

Yeast hydrolysate reduces body fat of dietary obese rats.

The purpose of this study was to assess the antiobesity effect of the yeast hydrolysate (DNF) on the body weight, body fat and plasma lipids levels of high-fat fed rats. The weight gain of the HF (high fat diet) (162.58 +/- 6.68 g) was significantly (p < 0.05) greater than that of DNF-1, DNF-2, (high fat diet with DNF of 0.5 and 1.0 g/kg body weight, respectively) and control groups (143.19 +/- 7.33 g, 139.20 +/- 8.36 g, 130.23 +/- 8.02 g, respectively). The wet weight of the epididymal fat and the perirenal fat pads of the DNF-1, DNF-2 and control groups were reduced significantly (p < 0.05). A significant (p < 0.05) increase of HDL-cholesterol level of the DNF-2 and control groups was observed. However, there was no significant difference between DNF-1 and DNF-2. It was also found that the triacylglycerol (TG) levels decreased significantly (p < 0.05) in the DNF-2 group from that of the HF, but there was no significant (p < 0.05) difference between DNF-1 and DNF-2.