Effects of solid-state fermented rice on lipid metabolism and antioxidant status in high-cholesterol-fed rats

We investigated the effect of solid-state fermented rice cultured with Basidiomycota (sangwhang) and Monascus ruber on lipid metabolism and antioxidant activity. Forty 4-week-old male Sprague-Dawley rats were fed high cholesterol diets in which carbohydrate sources in the treatment groups consisted of non-fermented rice and sangwhang or M. ruber rice at 80% and 20%, respectively, for 5 weeks. Supplementation with sangwhang and M. ruber rice had no effect on growth and food intakes in high-cholesterol-fed rats. The plasma triglyceride concentration was not significantly different among the groups. Supplementation with M. ruber rice resulted in lower plasma and hepatic cholesterol concentrations and atherogenic index compared to the control group, while the plasma high-density lipoprotein-cholesterol concentration was elevated. In addition, fermented rice cultured with M. ruber-supplemented animals had greater bile acid excretion. The M. ruber groups had significantly lower plasma and hepatic levels of thiobarbituric acid-reactive substances than the control group. Moreover, hepatic antioxidant enzyme activities, including catalase and superoxide dismutase, were significantly higher in the M. ruber group. In conclusion, fermented rice, especially M. ruber rice, was very effective for improving the lipid metabolism and reducing oxidative stress by up-regulating the hepatic antioxidant enzymes in high-cholesterol-fed rats.