Comparative Antihyperglycemic Effect of Petroleum Ether, Acetone, Ethanol and Aqueous Extracts of Cleome rutidosperma DC and Senecio biafrae (Oliv. and Hiern) in Streptozotocin-induced Diabetic Mice

The present study aimed to investigate the acute antihyperglycemic effects of four different solvent extracts (Petroleum ether, acetone, absolute ethanol and water) of two plants: Cleome rutidosperma (leaves) and Senecio biafrae (root) in STZ-induced diabetic mice and their in vitro antioxidant activities as well as their phytoconstituents. A single administration of the extracts at a dose of 500mg/kg body weight was done. All extracts as well as the standard drug, glibenclamide (at 600 μg/kg body weight) significantly lowered blood glucose level (p<0.05) of the diabetic mice by 28.784±15.4640.866±15.61% for Cleome rutidosperma and 10.652±6.3619.858±7.65% for Senecio biafrae within 6 hrs of extracts administration. The effect was more pronounced in the aqueous extracts of both plants. The median lethal dose (LD50) of the extracts in rats was found to be > 5000 mg/kg body weight. The tested plant extracts displayed appreciable level of antioxidant activities by different assay methods: the ferric thiocyanate (FTC) method (26.42±1.75-56.46±2.83%), the thiobarbituric acid (TBA) method (18.43±1.6748.17±2.19%), reducing power method (22.76±1.87-68.45±1.07%) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method (26.23±0.94-66.12±1.41% inhibition). Quantitative phytochemical analysis of the extracts revealed the presence of Alkaloids (0.11±0.02-0.34±0.05%), Saponins (0.18±0.02-6.01±0.88%), Tannins (0.04±0.01-14.15±0.73%), Glycosides (0.002±0.001-0.113±0.040%), Phenols (0.02±0.01-0.21±0.02%), Flavonoids (0.012±0.003-0.433±0.170%) and Steroids (0.003±0.001-0.011±0.003%). Therefore, the results indicate that extracts of Cleome rutidosperma and Senecio biafrae possess significant antidiabetic and in vitro antioxidant activities. They are also rich in phytochemicals.