Blighia sapida leaves halt elevated blood glucose, dyslipidemia and oxidative stress in alloxan-induced diabetic rats.

Blighia sapida leaves are used in the management of diabetes in Nigeria. Thus the antidiabetic activity of methanolic Blighia sapida leaf extract and its capability to halt oxidative stress and dyslipidemia in alloxan-induced diabetic rats were investigated. In vitro antioxidant activity of the extract (0.2-1.0mg/mL) was investigated using 2,2-diphenyl-1-1picrylhydrazyl (DPPH) radical, superoxide ion, hydrogen peroxide, and hydroxyl radical and ferric ion reducing system. Antidiabetic was evaluated in alloxan-induced diabetic rats. The methanolic extract of Blighia sapida leaves at 1.0mg/mL scavenged DPPH, superoxide ion, hydrogen peroxide, and hydroxyl radical at 80.34%, 57.39%, 72.36% and 77.0% respectively, while ferric ion was significantly reduced. Single oral dose of the extract significantly reduced blood glucose level in a dose dependent manner with highest dose producing 18.6% reduction after 240min. Similar reduction was produced after 28 days of extract administration with the highest dose producing 65.65% reduction which compared significantly (P<0.05) with the control group and glibenclamide treated groups. Alloxan-induced diabetic mediated alterations in liver and serum cholesterol, triacylglycerides, high-density lipoprotein cholesterol (HDLc), low density lipoprotein (LDL) cholesterol and very low-density lipoprotein cholesterol (VLDLc) were significantly (P<0.05) restored by the extract. Methanolic extract of Blighia sapida leaves significantly attenuated the decrease in the activities of reactive oxygen species detoxifying enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose 6-phosphate dehydrogenase) in the liver and pancreas of alloxan-induced diabetic rats. Elevation in the concentrations of malondialdehyde, conjugated dienes, lipid hydroperoxides, protein carbonyl, and fragmented DNA was significantly (P<0.05) lowered by Blighia sapida leaves extract. Overall, methanolic extract of Blighia sapida leaves at all doses used reduced blood glucose level and prevented oxidative stress and dyslipidemia in alloxan-induced diabetic rats.