title: Effects of Jamaican bitter yam (Dioscorea polygonoides) and diosgenin on blood and fecal cholesterol in rats.
abstract: A sapogenin-rich preparation from Jamaican bitter yam (Dioscorea polygonoides) has been shown to reduce blood cholesterol concentrations in hypercholesterolemic rats and mice. Also, diosgenin supplementation has been reported to have antilipemic effects in several animal species. We investigated potential mechanisms of the lipid-lowering actions of bitter yam and also whether the actions were mediated by diosgenin. Sprague-Dawley rats were fed a hypercholesterolemic diet (4% cholesterol) alone or with 5% bitter yam or 1% diosgenin supplementation for 6 weeks. The control group was fed normal rat chow. The serum lipid profile, fecal cholesterol concentration, and serum lipase activity were assessed at the end of the period. The induction of hypercholesterolemia was inhibited by coadministration of 5% bitter yam or 1% diosgenin in the diet. Serum lipid profiles were similar in rats fed bitter yam or diosgenin. The fecal cholesterol concentration was significantly (P < .01) higher in rats fed diosgenin compared to the cholesterol group. However, there was no corresponding elevation in the group fed bitter yam. Administration of bitter yam or diosgenin supplement significantly increased (P < .01) the serum lipase activity compared to the normal control and cholesterol groups. The cholesterol-supplemented diet inhibited normal gain in body weight over the period. This action was potentiated by diosgenin. The effects of the respective supplements on body weight were not completely explained by food consumption. Supplementation of the diet with Jamaican bitter yam may be therapeutically beneficial in the management of hypercholesterolemia.
authors: 1 Pharmacology Section, Department of Basic Medical Sciences, University of the West Indies , Kingston, Jamaica .
authors: Marsha-Lyn
authors: ML
authors: McKoy
authors: Peta-Gaye
authors: PG
authors: Thomas
authors: Helen
authors: H
authors: Asemota
authors: Felix
authors: F
authors: Omoruyi
authors: Oswald
authors: O
authors: Simon
mesh_terms: D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002784:Cholesterol / Q000097:blood* / Q000378:metabolism; D059305:Diet, High-Fat; D019587:Dietary Supplements; D027742:Dioscorea / Q000737:chemistry*; D004144:Diosgenin / Q000494:pharmacology / Q000627:therapeutic use*; D005243:Feces / Q000737:chemistry; D006937:Hypercholesterolemia / Q000097:blood / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D007563:Jamaica; D008049:Lipase / Q000097:blood; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*; D017207:Rats, Sprague-Dawley; D015430:Weight Gain / Q000187:drug effects
chemical_list: D000924:Anticholesteremic Agents; D010936:Plant Extracts; D002784:Cholesterol; D008049:Lipase; D004144:Diosgenin
keywords: bitter yam; body weight; cholesterol diet; hypercholesterolemia; lipase; mechanism of action