Subacute antidiabetic and in vivo antioxidant effects of methanolic extract of Bridelia micrantha (Hochst Baill) leaf on alloxan-induced hyperglycaemic rats.

The methanolic leaf extract of Bridelia micrantha was tested for subacute antidiabetic and in vivo antioxidant effects in alloxan-induced hyperglycaemic rats. The subacute treatment of the extract (125, 250 and 500 mg/kg) produced 75, 68 and 63% reduction in fasting blood sugar level respectively, on day 14 of treatment. The extract produced time-dependent effect, but did not show a dose-dependent effect. Its optimum antidiabetic activity was noted at the dose of 125 mg/kg and this was comparable to glibenclamide 2 mg/kg (positive control). The extract (125 mg/kg) showed good oral glucose tolerance test (OGTT) effect in both normoglycaemic and hyperglycaemic rats. The OGTT effect of the extract (125 mg/kg) did not differ significantly (p>0.05) from glibenclamide (2 mg/kg). The antioxidant effect of the extract was assayed through the determination of the level of thiobarbituric acid reactive substance (TBARS) and catalase activity. The extract produced a dose-dependent decrease in the serum level of TBARS and gave its optimum catalase activity at the dose of 500 mg/kg. This study suggests that the B. micrantha extract has antihyperglycaemic and antioxidant activities. Therefore, could be a potential source of novel antidiabetic and antioxidant agent for the management of diabetes mellitus.