SFE2005 Poster Presentations Diabetes, metabolism and cardiovascular (10 abstracts)
Previous studies in our laboratories suggest that Hypoxis hemerocallidea corm (African Potato) extract has a potential in the management of diabetes mellitus. Accordingly, we investigated the short-term effect of Hypoxis hemerocallidea corm ethanolic crude extract (APE) on blood glucose levels of Wistar rats (250–300 g b.wt). Oral glucose tolerance tests (OGTT) were conducted in five separate groups (n=6 in each group) of male Wistar rats (250–300 g b.wt). The animals were starved for 16 hours and administered with glucose (0.86 g. mg.kg−1 b.wt) by gastric gavage, followed by graded doses of APE (60, 120 and 240 mg.kg−1 p. o.). Blood glucose concentrations were monitored at 15 min intervals for the first hour, and hourly thereafter for the next 3 hours. A separate group of animals treated with metformin (500 mg/kg p. o.) served as the treated control. Animals treated with deionised water (3 ml/kg p. o.) served as the untreated control animals. Statistical significance was determined by using Graph Pad Prism (version 2.00) Software. The data were subjected to analysis of variance using a one-way design and Scheffes multiple comparison test was used to assess any differences. A value of p<0.05 was considered significant. APE (60–240 mg.kg−1 p. o.) decreased blood glucose concentrations of the rats in a dose-dependent manner; with low to moderate doses of APE exerting their maximum hypoglycaemic effects after 30 minutes. The median dose of APE (120 mg.kg−1) decreased blood glucose levels from a peak of 6.9±0.2 mmol.l−1 to 5.9±0.2 mmol.l−1 by 30 minutes. Metformin (500 mg.kg−1 p. o.) induced a sustained, highly significant (P<0.001) reduction in the blood glucose levels of the animals. Findings from the present study indicate a short-term hypoglycemic effect of oral administration of APE in rats, presumably in a mechanistic manner similar to that of metformin.