Hypoglycemic activity of leaves of Acanthus montanus T.Anderson (Acanthaceae) in rats

Abstract

Hypoglycemic activity of Acanthus montanus, used locally in Nigeria to “cure” diabetes, was evaluated. Phytochemical tests and acute toxicity tests were carried out on the methanolic extract. Using normoglycemic and alloxanized (alloxan monohydrate 70 mg/kg IV body weight) rats, pre-treatment was done with 400 mg/kg of the extract and glibenclamide 10 mg/kg as reference drug orally. Blood glucose levels of the rats were measured at various time intervals (0, 1, 2, 3, 4, 6 h). In addition, a dose dependency test was also done with alloxanized rats using 100 and 200 mg/kg of the extracts. Glucose levels were analyzed statistically using ANOVA and Dunnett’s tests. The extract revealed abundance of alkaloids, terpenoids, glycosides and flavonoids. Acute toxicity tests showed an oral LD50 of 4,800 mg/kg. With the exception of glibenclamide 10 mg/kg (glucose reduction to 44 mg/dl, p < 0.01) there was no significant reduction in glucose level in normoglycemic rats in all the treatments at 6 h. In alloxanized rats, there was significant reduction of glucose level by the extract and glibenclamide compared to control 2 h after treatment. Mean percentage reduction of glucose showed a time dependent increase in glucose reduction by the extract with a maximum reduction of 67.1%, P < 0.01, at 6 h. A dose dependent glucose reduction was seen with increasing doses of the extract till the 6 h time after treatment. This study suggests that the methanolic extract of Acanthus montanus T.A possesses a hypoglycemic effect.