Effects of Yucca Saponin and Konjak Flour on Lipid Metabolism of Rats Fed a High-fat Plus High-cholesterol Diet

Abstract

The effects of yucca saponin and konjak flour on lipid metabolism were investigated using male Wistar rats weighing about 290g. The rats were divided into 5 groups; control, yucca saponin, soybean saponin, konjak flour, and yucca saponin plus konjak flour groups. All the rats were fed a high-fat diet containing cholesterol for 4 weeks, followed by the experimental diets for a further 2 weeks. The diets were preparedby adding 1.5% yucca saponin, 1% soybean saponin, 3% konjak flour, or 1.5% yucca saponin plus 3% konjak flour, respectively. There was no significant difference in food intake in any of the experimental diet groups when compared to the control group. The ratio of abdominal adipose tissue weight to body weight decreased in both the konjak flour and the yucca saponin plus konjak flour groups. The excretion rate of cholesterol in feces increased, and the serum and liver cholesterol concentrations were reduced in both the yucca saponin and the yucca saponin plus konjak flour groups. Although there was no significant difference in the excretion rate of cholesterol between the soybean saponin and the konjak flour groups, the serum total cholesterol concentration decreased in the soybean saponin group. Total lipid, cholesterol and triglyceride in the liver decreased in the yucca saponin group and were more reduced in the yucca saponin and konjak flour groups. These results suggest that a diet containing yucca saponin and konjak flour improves lipid metabolism in rats fed a high-fat and high-cholesterol diet.