Cholesterol-lowering effect of water-soluble polysaccharides from kenaf (Hibiscus cannabinus) seeds in rats I

The effects of kenaf (Hibiscus cannabinus) seeds on serum and liver lipid concentration in rats were investigated. Rats were fed a hypercholesterolemic diet (containing 1% cholesterol and 0.25% cholic acid) supplemented with 5% kenaf seed powder or 5% hot-water extract from the calyx of Thai kenaf (Hibiscus sabdariffa). The serum cholesterol concentration was significantly lower in the rats fed the diet supplemented with seed powder than in rats of the control group. The extract from the flower did not exert a similar effect. The HDL-cholesterol concentration in the serum was not converted, but the (VLDL+LDL)-cholesterol concentration decreased as compared to the control group. No significant differences in liver cholesterol concentration were observed for all substances tested. Rats were fed a diet containing polysaccharide extracted from the seeds collected in the Hunan and Zhejian regions of China. The serum cholesterol concentration was significantly lower in the rats fed a diet supplemented with 1% or 5% polysaccharides as compared to control group, but did not differ significantly between the two regional seed sources. There was no significant difference in liver cholesterol concentration between the control and the treatment groups. The results suggest that the polysaccharides extracted from kenaf seeds have serum cholesterol-lowering effects in rats.