Hypoglycemic activity of the stem bark extract of Anacardium occidentale linn (Anacardiaceae) in alloxaninduced diabetic rats

Anacardium occidentale Linn (Family: Anacardiaceae) stem bark has been used for the treatment of various ailments. The effect of methanol extract, n-hexane fraction and chloroform fraction of Anacardium occidentale stem bark on Alloxan-induced diabetic rats was investigated. Diabetes mellitus was induced with 120 mg/kg Alloxan; manifestations of hyperglycaemia were checked with glucometer after 1 h, 2 h and 4 days of induction. Twenty-five white Wistar rats weighing 170-220 g were used for this study. The animals were divided into five groups with group one, serving as thenegative control, given 0.9% normal saline and group two as the positive control receiving 100 mg/kg metformin. Group three received 100 mg/kg of the n-hexane fraction, group four, 100 mg/kg of chloroform fraction and group five, 100 mg/kg of methanol extract. The pharmacological screeningindicates that the n-hexane and chloroform fractions, as well as the methanolic extracts of Anacardium occidentale at 100 mg/kg produced a significant blood glucose reduction in the rats (p<0.01) when compared with the negative control. The level of reduction in the blood glucose exhibited by the chloroform fraction was similar to that produced by the standard agent (metformin), while the nhexane fraction exhibited greater reduction. When the n-hexane and the chloroform fractions were compared with the crude methanolic extract, the fractions possessed more hypoglycaemic effect. The result of the phytochemical analysis revealed the presence of alkaloids, flavonoids, tannins, saponins, phenols, oxalate and phytate. These study suggest that the stem bark of extract/fractions of Anacardium occidentale possesses antidiabetic property on alloxan-induced rats.This justifies its use in ethnomedicine and can be exploited in the management of diabetes.KEY WORDS: Hypoglycaemic activity, Anacardium occidentale, Stem bark, Alloxan, Methanol extract/Fractions