High protein buckwheat flour suppresses hypercholesterolemia in rats and gallstone formation in mice by hypercholesterolemic diet and body fat in rats because of its low protein digestibility

Objective: This study evaluated the physiologic properties of high protein buckwheat flour (PBF) by examining its effects on serum cholesterol and body fat in rats and on cholesterol gallstone fort-nation in mice. Methods: Animals were fed experimental diets that contained casein, buckwheat protein extract (BWP), or PBF as a protein source (net protein content 200 g/kg). Results: In experiment 1, consumption of PBF and BWP for 10 d caused 33% and 31% decreases, respectively, in serum cholesterol of rats fed cholesterol-enriched diets when compared with consumption of casein (P < 0.05). Dietary PBF caused a significant decrease in liver cholesterol, whereas dietary BWP caused only a slight decrease (P > 0.05). Fecal excretion of neutral and acidic steroids in the PBF group was significantly higher than those in the BWP and casein groups. In experiment 2, consumption of PBF for 10 d significantly suppressed adipose tissue weight and hepatic activity of fatty acid synthase in rats fed cholesterol-free diets compared with consumption of casein (P < 0.05), whereas that of BWP for this period caused only a slight decrease in adipose tissue weight (P > 0.05). In experiment 3, dietary PBF and BWP significantly decreased the incidence of cholesterol gallstones and lithogenic index in mice fed cholesterol-enriched diets for 27 d, which was associated with increased fecal excretion of acidic steroids. Conclusion: This study demonstrated that PBF has strong activities against hypercholesterolemia, obesity, and gallstone formation, suggesting a potential usefulness of PBF as functional ingredient. (c) 2006 Elsevier Inc. All rights reserved.