Effect of acute and chronic administration of Persia americana (chloroform extract of stem bark) on blood glucose concentration of normoglycaemic and streptozotocin-induced hyperglycaemic mice

Abstract

The effect of acute and chronic administration of the chloroform extract of the stem bark of P. americana on the blood glucose concentration (BGC) of normoglycaemic and streptozotocin (STZ)-induced hyperglycaemic mice was investigated. Firstly, fifteen (15) young albino mice allocated into three groups of five animals each after a 12 hour overnight fast were treated as follows: group 1 – equi-volume of distilled water, group 11- a single acute dose of 1200 mg/kg IP chloroform extract of P. americana (equivalent to 75% of LD50) and group 111 – 20 mg/kg IP tolbutamide. Immediately after treatment, BGC was measured at 0, ½, 1, 2, 4, and 8 hrs. Secondly another population of 15 animals were shared into 3 groups of 5 animals each. Animals in group 1 were administered equi-volume of distilled water daily, group 11 and group 111 400 mg/kg IP (equivalent to 25% of LD50) extract of P. americana and 10 mg/kg IP of tolbutamide respectively daily for twenty- five days. BGC was measured on days 1, 5, 10, 15,20, 25. Changes in BGC of normoglycaemic and STZ-induced hyperglycaemic mice as a result of acute and chronic administration of extract was compared with values for tolbutamide (positive control) and distilled water (negative control). Results show that in normoglycaemic mice unlike the acute dose of 20 mg/kg IP reference drug tolbutamide, an acute dose of the extract (1200 mg/kg IP) did not significantly lower BGC. In the STZ-induced hyperglycaemic mice however, both the extract and the reference drug tolbutamide significantly lowered the BGC. With chronic administration both the extract and the reference drug significantly lower BGC in STZ-induced hyperglycaemic mice. It can be concluded therefore that acute and chronic administration of the chloroform extract of P. americana does have a hypoglycaemic activity only in STZ-induced hyperglycaemic mice. This may support the use of the stem bark of P. americana in the treatment of Diabetes mellitus.