Phytochemical Constituents and Lipid Lowering Actions of Extracts of Picralima nitida Seed and Tapinanthus bangwensis leaf in Alloxan-induced Diabetic Rabbits

Abstract

Diabetes, a metabolic syndrome, is characterized by disordered metabolism including hyperlipidaemia. Orthodox approach of managing  diabetes poses risk of inflicting heart diseases amongst others, hence, the search for alternative therapy. In Nigeria, many herbalists have  claimed to use coconut water extract of Picralima nitida seed and aqueous extract of Tapinanthus bangwensis leaf in the  management of diabetes, amongst which are their lipid lowering actions. This study aims to provide evidence for the presence of some  phytochemicals which have been found to enhance the lipid lowering actions of the plant extracts in the diabetic state. The experimental  rabbits (Chinchilla) (1.12 ± 0.09 kg) were grouped into six and extracts administered orally, once daily for five weeks. Groups 1 and 2 (non- diabetic) received only distilled water and coconut water respectively, group 3 (diabetic) received 200 mg/kg body weight aqueous extract  of T. bangwensis leaf, group 4 (diabetic) received 400 mg/kg body weight of coconut water extract of P. nitida seed, groups 5 and  6 (diabetic) received only distilled water and coconut water respectively. The lipid lowering effects of extracts on total lipid and  cholesterol concentration in both the plasma and selected tissues (liver, kidney and heart) were assessed. The results revealed that the  extracts independently lowered significantly (p<0.05) the blood total lipid and cholesterol levels of the diabetic rabbits. Both extracts  significantly (p<0.05) decreased the total lipid concentrations in the tissues. The extracts revealed the presence of some phytochemicals  (Alkaloids, Flavonoids, Saponins amongst others) which possibly contributed to their lipid lowering actions Overall, aqueous extract of T.  bangwensis leaf and coconut water extract of P. nitida seed respectively, can be advocated plants as lipid lowering agents in the  management of diabetes.