Increased Plasma and Liver Lipids in Streptozotocin-induced Diabetic Rats: Effects of Yam (dioscorea Cayenensis) or Dasheen (colocassia Esculenta) Extract Supplements

The effects of incorporating cyanoglucoside extracts from yam or dasheen into the diet of streptozotocin-induced diabetic Wistar rats were studied for four weeks. Intestinal lipase activity, and plasma glucose and lipid levels were determined. Also, liver total lipids, activities of ATP citrate lyase, pyruvate kinase and 6-phosphogluconate dehydrogenase were assessed. Dasheen extract significantly lowered plasma levels of glucose and triglycerides (p<0.05). Yam or dasheen extract supplementation significantly decreased plasma levels of cholesterol and HDL cholesterol. Similarly, supplementation with commercial linamarin significantly reduced plasma HDL cholesterol. Yam or dasheen extract supplementation significantly increased the activity of 6-phosphogluconate dehydrogenase. The two supplements significantly lowered liver total lipids towards normal, whereas commercial linamarin supplementation significantly increased liver total lipids above normal. These observations showed the acute intake of dasheen extract to lower the level of triglycerides, which is desirable in diabetes, however, as it also lowered plasma HDL cholesterol, it may not be considered a useful dietary supplement in diabetics.