The Jamaican bitter yam (Dioscorea polygonoides) contains various bioactive components that may increase oxidative stress in various tissues at relatively high concentrations. The present study therefore investigated the effects of bitter yam supplementation (5%) on the integrity of the liver and kidneys. Two mice strains (inbred C57BL/6 and transgenic C57BL/6-Tg(APOA1)1Rub/J) were used in the study. Each strain was divided into two groups. One group was fed a basal diet without supplementation, and the second group was fed a basal diet supplemented with the Jamaican bitter yam. The results revealed that the transgenic mice fed diets with and without bitter yam supplementation experienced significant increases in weight, when compared with inbred mice fed similar diets. Hepatoprotective effects were observed in transgenic mice known to possess high serum high-density lipoprotein (HDL). Oxidative stress was induced in mice fed diets supplemented with bitter yam at a concentration of 5%.
The Jamaican bitter yam possesses potent anti-diabetic and hypocholesterolemic properties due to its high levels of sapogenin. Currently, the tuber is consumed in rural areas mostly during times of drought. No toxicology data, however, exist for consumption of this yam species. This study provides information on the possible toxicity from overconsumption and paves the way for future studies to establish an effective consumption dosage. With its potent cholesterol-lowering capabilities, the Jamaican bitter yam can be exploited in the nutraceutical industry and for the development of other value-added products for everyday consumption such as baked goods and granola bars, giving them a hypocholesterolemic twist.