An evaluation of the anti-diabetic properties Asparagus africanus Lam. root extracts

Abstract

Medicinal plants could be a good alternative in the prevention and treatment of diabetes and other diseases. Type II diabetes is becoming prevalent in society and it has become necessary to start looking at medicinal plants as potential antidiabetic treatments. The objective of this project was to evaluate the efficiency of Asparagus africanus root extracts for their potential application as sources of antidiabetic entities. Glucose uptake by Chang liver and C2C12 muscle cells treated with methanol and water extracts of A. africanus was investigated. Furthermore, the antioxidant (free radical scavenging) activity of A.africanus was carried out using 2, 2- diphenylpicrylhydrazyl assays. Cytotoxicity was analysed using the SRB assay. The phytochemical content of the extracts was determined through standard qualitative screening methods and liquid chromatography mass spectrometry. The extracts did not cause an increase in glucose uptake by the C2C12 muscle cells, but the methanol extract caused a marginal increase in glucose uptake by the Chang liver cells, suggesting that the antidiabetic activity exerted may actually take place in the liver. The antidiabetic test using the Chang liver cells and C2C12 muscle cells line showed some active glucose uptake compared to the control and reference drug. The plant also demonstrated moderate antioxidant properties with the concentration of a drug that gives half-maximal response (EC values) of EC50≤14.723 mg/ml, while the ascorbic acid standard of EC50 was 0.1157 mg/ml. The total phenolic concentration of the A.africanus at 2.5 mg/ml was 0.04% and had a Gallic acid equivalence of 0.01. Phytochemical screening indicated several bioactive constituents, such as alkaloids, carbohydrate, cardiac glycosides, protein, flavonoids, tannins, steroids, terpenoids and saponins contained in A.africanus roots. These might modulate the activities of ligand-dependent transcription factors, namely peroxisome proliferator-activated receptors (PPARs), PPARs are dietary lipid sensors that control energy homeostasis, daily consumption of these constituents might be useful for the management of obesity-induced metabolic disorders, such as type 2 diabetes, hyperlipidaemia, insulin resistance and cardiovascular diseases. Conclusively, the presence of aforementioned phytochemical constituents in A. africanus suggests that the plant might be a good inhibitor to reduce the risk of any cardiovascular diseases such as coronary heart diseases, heart failure and stroke, these diseases has similar symptoms as diabetes and hypertension.