title: Polysaccharide gel coating of the leaves of Brasenia schreberi lowers plasma cholesterol in hamsters.
abstract: Brasenia schreberi ( chún cài) is an invasive aquatic weed found in the USA, but the plant has economic value in Asia where it is cultivated for food. The young leaves of B. schreberi are coated with gelatinous water-insoluble mucilage. This mucilage is a polysaccharide composed of galactose, mannose, fucose, and other monosaccharides. Because some carbohydrate gels are hypocholesterolemic, we evaluated their cholesterol-lowering properties in male hamsters fed hypercholesterolemic diets containing 2% gel coat from B. schreberi (GEL), or 1% cholestyramine (CA), or 5% hydroxypropyl methylcellulose (HPMC), and compared them to 5% microcrystalline cellulose (control) for 3 weeks. We found that very-low-density lipoprotein-, low-density lipoprotein-, and total-cholesterol concentrations in plasma were significantly lowered by GEL, CA, and HPMC compared to control. High-density lipoprotein-cholesterol concentration was lowered by CA and HPMC. Body weights and abdominal adipose tissue weight of GEL and control group animals were greater than those of the CA and HPMC groups. Fecal lipid excretion was greater in the CA and HPMC groups than in the control group. Expression of hepatic CYP51 and CYP7A1 mRNA was upregulated by CA, HPMC, and GEL, indicating increased hepatic cholesterol and bile acid synthesis. Expression of low-density lipoprotein receptor mRNA was upregulated by all treatments. These results suggest that modulation of hepatic expression of cholesterol and bile acid metabolism-regulated genes contributes to the cholesterol-lowering effects of GEL.
authors.affiliation: Department of Nutrition, University of California, Davis, CA, USA ; Department of Physiology, College of Veterinary Medicine, Konkuk University, Seoul, South Korea.
authors.forename: Hyunsook
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Food Science, Jiangnan University, Wuxi, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Food Science and Technology, University of California, Davis, CA, USA.
authors.forename: Charles F
authors.initials: CF
authors.lastname: Shoemaker
authors.affiliation: Department of Food Science, Jiangnan University, Wuxi, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhong
authors.affiliation: USDA, ARS, Western Regional Research Center, Albany, CA, USA.
authors.forename: Glenn E
authors.initials: GE
authors.lastname: Bartley
authors.affiliation: USDA, ARS, Western Regional Research Center, Albany, CA, USA.
authors.forename: Wallace H
authors.initials: WH
authors.lastname: Yokoyama
keywords: Brasenia; cholesterol; gene expression; hamster; polysaccharide