title: Algal sterols are as effective as β-sitosterol in reducing plasma cholesterol concentration.
abstract: The present study examined the cholesterol-lowering activity of sterol extract (SE) derived from alga Schizochytrium sp. and its interaction with gene expression of transporters, receptors, and enzymes involved in cholesterol absorption and metabolism. GC-MS analyses found that SE was a mixture of various sterols including lathosterol, ergosterol, stigmasterol, 24-ethylcholesta-5,7,22-trienol, stigmasta-7,24(24(1))-dien-3β-ol, and cholesterol. Results showed that SE at doses of 0.06 and 0.30 g/kg diet were able to decrease plasma cholesterol concentration by 19.5 and 34%, respectively, compared with the control, in hamsters maintained on a 0.1% high-cholesterol diet. SE at a dose of 0.30 g/kg diet was as effective as β-sitosterol in reducing plasma total cholesterol (TC). SE-induced reduction in plasma TC was accompanied by down-regulation of intestinal acyl-CoA:cholesterol acyltransferase 2 (ACAT2) and hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and up-regulation of hepatic low-density lipoprotein (LDL) receptor. Addition of SE to the diet increased the excretion of total fecal sterols. It was concluded that SE possessed the same cholesterol-lowering activity as β-sitosterol and the underlying mechanisms were mediated by increasing sterol excretion and decreasing cholesterol absorption and synthesis.
authors.affiliation: Lipids Technology and Engineering, School of Food Science and Engineering, Henan University of Technology , Lianhua Road, Zhengzhou, Henan, China.
authors.forename: Jingnan
authors.initials: J
authors.lastname: Chen
authors.forename: Rui
authors.initials: R
authors.lastname: Jiao
authors.forename: Yue
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yanlan
authors.initials: Y
authors.lastname: Bi
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Chen
mesh_terms: D000818:Animals; D000924:Anticholesteremic Agents / Q000737:chemistry / Q000494:pharmacology*; D002784:Cholesterol / Q000097:blood*; D006224:Cricetinae; D015536:Down-Regulation / Q000187:drug effects; D055951:Functional Food / Q000032:analysis; D008297:Male; D008647:Mesocricetus; D058086:Microalgae / Q000737:chemistry*; D012855:Sitosterols / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000924:Anticholesteremic Agents; D012855:Sitosterols; C025473:gamma-sitosterol; D002784:Cholesterol
keywords: ACAT2; HMG-CoA-reductase; LDL receptor; algal sterol; cholesterol; β-sitosterol