Improvement of diabetic dyslipidemia by legumes in experimental rats

Abstract

Grain legumes are a valuable source of food proteins; hence, their exploitation is expected to grow in relation to a growing world's food needs. Apart from high level of dietary fibre, their protein composition makes them useful in managing diabetes. This paper reports a study conducted to evaluate the effects of four different non-soy legume-based (Vigna unguiculata ssp. dekindtiana var dekindtiana, Vigna unguiculata ssp. unguiculata, Sphenostylis stenocarpa and Vigna subterranea) diets in rats administered with alloxan monohydrate (150 mg/kg bodyweight). Concentration of plasma glucose, triacylglycerol, total cholesterol, HDL-cholesterol and HDL-triacyglycerol as well as hepatic levels of cholesterol and triacylglycerols were determined spectrophotometrically in alloxan-induced diabetic rats fed on these legumes for five weeks. Induction of rats with alloxan monohydrate led to significant (p<0.05) elevation of fasting plasma glucose and reduction in body weight. Consumption of each of the four legumes led to a significant reduction in the fasting plasma glucose concentrations in the diabetic rats (p<0.05) with V. subterranean causing about 60% reduction. Vigna unguiculata ssp. dekindtiana var dekindtiana and Sphenostylis stenocarpa caused a reversal of the diabetes-induced reduction of hepatic cholesterol (p<0.05). Plasma dyslipidemia was observed in the alloxan-induced diabetic rats as significant (p<0.05) increases in total cholesterol, triacylglycerols, HDL-cholesterol, HDL-triacylglycerols and LDL-cholesterol levels were observed. The legumes improved the plasma lipid profile as shown by a significant (p<0.05) reduction in the ratios of total cholesterol/HDL-cholesterol (ranging from 1.25-2.25 for control groups to 1.00-1.35 for the legume-fed groups) and LDL-Cholesterol/HDL-Cholesterol (ranging from 0.50-1.75 for control groups to 0.50-0.75 for the legume fed groups). The results suggest that wild cowpea, white cowpea, african yam bean and bambara groundnut equally reversed diabetes-associated dyslipidemia as indicated by the indexes of cardiovascular disorder. This, therefore, underscores the potential of these underutilized legumes in managing dyslipidemia associated with diabetes in experimental rats. These data should contribute toward enhancing the nutraceutical potential and utility of these legumes.

Keywords: Diabetes, lipid profile, rats, legumes

African Journal of Food, Agriculture, Nutrition and Development, Volume 13 No. 2, April 2013