McKoy, Marsha-Lyn G.; .; Omoruyi, Felix O.; Simon, Oswald R.; Asemota, Helen N.
Author Affiliation, Ana.
Departemnt of Basic Medical Sciences
Investigation of the Effects of a Sapogenin Rich Preparation from a Jamaican Yam (Dioscorea sp.) on Blood Cholesterol Levels in Rats
Proceedings of the Western Pharmacology Society
Date of Publication
Hypocholesterolemia (serum cholesterol ³ 240 mg/dl) has been associated with the development of atheroscelosis with its related cardiovascular complications including hypertension, coronary artery disease and strokes in man. In many countries, these diseases account for high mortality rates. For the period 1997-2001, cardiovascular diseases were the leading cause of death among patients ³ 50, years in Jamaica's public hospital system. The statistics indicate the need for an increased drive to maintain cholesterol within an acceptable range, by dietary modifications and/or pharmacological interventions. Sapogenins, especially diosgenin, have been shown to reduce blood cholesterol in several animal species by inhibiting intestinal absorption of cholesterol. Although compensatory increases in hepatic and intestinal cholesterol synthesis were also reported, this was accompanied by increased secretion of cholesterol in bile, the net effect being lowering of plasma cholesterol. Evidence has also been presented for a role of some soponins in increasing bile acid excretion. This would increase the rate of cholesterol catabolism as is the mechanism by which the commercially available 'bile acid sequestrants' produce their hypocholesterolemic effect. Yams are a major source of diosgenin and Jamaica has at least 15 yam varieties, several of which are comsumed locally as dietary staple. The terms 'yams' and 'sweet potato' are often used interchangeably in the USA. However, specific references are made here to the monocotyledon Dioscorea species (yam), which is rough and scaly, in appearance and dry and starchy to the taste as compared to the dicotyledonous Ipomoea batatas (potato) with its smooth, thin skin and moist, sweet taste. This study was designed to investigate the potential of exploiting Jamaican yams as an economic alternative of lowering blood cholesterol levels. The specific objectives were to include a hypercholerterolemic state in rats by feeding them a high-cholerterol diet, and thereafter, to investigate the effects of a preparation from a Jamaican yam of high sapogenin content on blood lipid distributions in the hypercholesterolemic animals.....