Jamaican Bitter Yam Sapogenin: Potential Mechanisms of Action in Diabetes

Abstract

Sapogenin has been proposed to be the active component responsible for the beneficial effects of Jamaican bitter yam (Dioscorea polygonoides) in the management of diabetes. Most of the research activities on bitter yam have focused on the role sapogenin play in the management of diabetes. Changes in weight, activities of carbohydrate digestive and transport enzymes, alterations in the intestinal morphology, changes in blood lipids, reduction in lipid peroxidation and the prevention of liver damage associated with diabetes have all been attributed to bitter yam sapogenin supplementation. Also, the possible exploitation of bitter yam for nutraceutical/pharmaceutical purposes is based on the high saponin content. There are however, concerns about the beneficial claims of the findings especially with regard to the possible adverse effects that may accrue in the clinical applications. This review therefore provides an overview of the findings in this research area with a view to proposing the potential mechanisms whereby the supplement of bitter yam sapogenin extract exert its hypoglycemic and hypolipidemic properties and the probable adverse effects in diabetes mellitus.

Diosgenin present in fenugreek improves glucose metabolism by promoting adipocyte differentiation and inhibiting inflammation in adipose tissues

“…Of these, the saponin content is higher than those of the other two substances. It has been demonstrated that some saponin components have hypoglycemic effects 32, 33. Therefore, we investigated the effect of the saponin fraction from fenugreek on adipocyte differentiation in 3T3‐L1 cells.…”

Diosgenin, a Steroid Saponin Constituent of Yams and Fenugreek: Emerging Evidence for Applications in Medicine

“…There are several reports suggesting that diosgenin-rich food sources such as fenugreek seeds and yam tubers contribute to anti-diabetic effects in experimental models (Basch et al, 2003;Omoruyi, 2008). Evidence from human clinical trials clearly suggests that fenugreek seeds improve blood glucose and other metabolic parameters leading to treatment of diabetes (Basch et al, 2003).)…”

Effects of Jamaican Bitter Yam (Dioscorea polygonoides) and Diosgenin on Blood and Fecal Cholesterol in Rats

“…14 Saponins such as diosgenin-related compounds also reportedly slow the rate of gastric emptying, possibly through reduced activity of gastrointestinal enzymes. 15 We previously reported that a sapogenin-rich preparation from Jamaican bitter yam (D. polygonoides) significantly reduced blood cholesterol in hypercholesterolemic SpragueDawley rats. 16 However, the mechanism by which bitter yam lowers blood cholesterol is not known.…”