Proximate And Phytochemical Composition Of African Yam Bean (Sphenostylis Stenocarpa) And Its Effect On The Lipid Profile Of Hypercholesterolemic Rats

Abstract

The study examined the proximate and phytochemical (saponins, tannins, phytate and flavonoid) composition of roasted cream coloured African yam bean (AYB) flour and the lipid profile of hypercholesterolemic rats fed diets supplemented with African yam bean. Different diets were formulated using the AYB flour. Group 1 consisted of the normal control rats (untreated rats), group 2 consisted of the hypercholesterolemic group of rats that were untreated. Groups 3-6 consisted of rats fed rat chow with 5%, 10%, 15% and 20% AYB flour supplementation, respectively. Proximate analysis was done using AOAC methods. Phytochemical and biochemical analyses were done in duplicates using standard methods. The proximate analysis showed that AYB flour contain 4.94% moisture, 27.66% protein, 4.29% fat, 3.66% ash, 9.57% crude fibre and 49.88% carbohydrate. The phytochemical analysis showed 0.77mg/100g saponins, 42.07mg/100g tannins, 9.08mg/100g phytate and 1.01mg/100g flavonoid. Total cholesterol level for the different supplementation groups showed significant decrease (p<0.05) with 20% supplementation showing the highest decrease (38.70%). Triglyceride levels decreased significantly (p<0.05) across all the groups. The 5% AYB supplementation showed the highest decrease (35.63%) and 20% supplementation the lowest decrease (28.01%). Low density lipoprotein (LDL) levels of the rats significantly (p<0.05) decreased across the groups. The control group also showed 50.34% decrease in LDL but 10% AYB supplementation showed the highest decrease (61.29%). Serum high density lipoprotein (HDL) concentration increased significantly (p<0.05) after supplementation with AYB. The 20% AYB supplementation showed the highest percentage increase (22.85%) relative to the other groups. There were significant decreases in serum total cholesterol, LDL cholesterol, triglyceride and increase in HDL cholesterol for the groups with AYB supplementation.