Bioprospecting the antidiabetic potential of aqueous seed extract of Allanblackia floribunda Oliv. (Clusiaceae)

Allanblackia floribunda seeds are used for the treatment of diabetes mellitus in African traditional medicine, but its efficacy has not been sufficiently studied. This study aimed to assess the subacute toxicity and possible antidiabetic effects of the aqueous extract of A. floribunda seeds (AFE). To assess its possible antidiabetic effect, an oral glucose tolerance test (OGTT) was conducted in rats fasted overnight and subsequently treated with metformin, AFE (30, 100 or 300 mg/kg), or normal saline before the administration of oral glucose solution (2 g/kg). Fasting blood glucose (FBG) was measured in blood collected from the tail vein at 0, 30, 60, 120, and 180 minutes. Additionally, experimental diabetes was induced in rats via the use of streptozotocin in 20 mM citrate buffer (60 mg/kg, i.p.). The rats were then treated with AFE or metformin daily for 28 days. FBG was measured every 7 days. The animals were humanely sacrificed, and pancreas and blood samples were collected for examination. In the OGTT, AFE suppressed blood glucose levels in a statistically significant (p < 0.05) manner. Furthermore, AFE reversed the abnormalities in FBG and hematological and biochemical parameters induced by STZ in a statistically significant ( p <0.05) manner. AFE exhibited glucose-lowering activity as well as antidiabetic properties in rats.