Angiotensin I-converting enzyme inhibitory activity and hypocholesterolemic effect of some fermented tropical legumes in streptozotocin-induced diabetic rats

Cardiovascular disease (CVD) is the common cause of morbidity and mortality in diabetes. Any antidiabetic management strategy should therefore include the control of CVD risk factors. Thus, this study describes the effect of fermented legume condiment-supplemented diets on lung angiotensin I-converting enzyme (ACE) and lipid profile in streptozotocin (STZ)-induced diabetic rats. Adult male Wistar rats were used for the study and diabetes was induced in them by a single intraperitoneal injection of STZ (35 mg/kg b.w.). After the diabetic status had been confirmed, the animals were randomly divided into six groups consisting of six animals each and were fed with diets supplemented with fermented Bambara groundnut, locust bean, and soybean. The study lasted for 14 days after which the plasma was analyzed for the lipid profile and the rats’ lungs were assayed for ACE activity. Elevated ACE activity, plasma total cholesterol, triglyceride, and LDL-cholesterol showed significant (P < 0.05) reduction in the rats treated with fermented legume condiment-supplemented diets, with a concomitant increase in plasma HDL-cholesterol as compared with the diabetic control. This study therefore concludes that fermented legume condiment-supplemented diets could attenuate diabetes-induced dyslipidemia, a major coronary disease risk factor, in experimental rats. This health benefit of the condiment diets could be associated with their ACE inhibitory and antihypercholesterolemic properties. However, the diet supplemented with fermented locust bean condiment appeared to be the most potent.