Abstract:

This study was conducted for examining if soybean dregs rich in dietary fiber would enhance the alleviating effect of resistant starch on estrogen deficiency-induced hypercholesterolemia in ovariectomized rats. Total 32 adult female Wistar rats were subjected to bilateral ovariectomy and randomly divided into 4 groups: control group, soybean dregs (SD) group, resistant starch (RS) group and soybean dregs + resistant starch (SD + RS) group, which were fed diets containing total dietary contents of 2.6%, 41.7%, 39.8% and 40.5%, respectively. After 5 weeks of feeding, rats were sacrificed and anatomize and the levels of triglyceride and cholesterol in serum and liver, cholesterol 7α-hydroxylase activity in liver, bile acid pools in small intestine and cecum, and excretion of bile acid in feces were measured. Results showed that RS and RS + SD groups exhibited a significant decrease in total cholesterol content in serum and liver (P < 0.05), SD and SD + RS groups exhibited a significant decrease in serum triglyceride content (P < 0.05), and SD + RS group exhibited significant increases in intestinal bile acid pool, fecal excretion of bile acids and cholesterol 7α-hydroxylase activity in liver when compared to control group (P < 0.05). In conclusion, soybean drags can significantly enhance the hypolipidiamic effect of resistant starch, and the hypocholesterolemic effect of resistant starch appeared to be mediated by accelerated fecal excretion of bile acids and increases in intestinal pools.

Key words: soybean dregs, resistant starch, blood lipid, bile acid, ovariectomized rats