Abstract
Background: Biomedical researches have long sought to develop novel therapies that are more effective, less costly and possess fewer side effects, to treat chronic diseases including diabetes mellitus. Adiantum capillus is among the medicinal plants that have been widely used in traditional medicine and are known to have hypoglycemic effects. This study was designed to find the chemical constituent of Adiantum capillus that exerts the hypoglycemic effect. Materials and Methods: Fifty-four rats were split into nine groups. Twelve normal rats were included in the first group; six acted as negative controls and six were administered Adiantum capillus water extract. The second group was comprised of 42 streptozotocin-induced diabetic rats sectioned into seven subgroups of six rats. The first subgroup functioned as a positive control. The second subgroup was administered 100 mg/kg/day of Adiantum capillus aqueous extract for 21 days, while the third and the fourth subgroup received 50 mg/kg/day of metformin and acarbose respectively. The remaining three groups were administered alkaloids (4 mg/kg/day), flavonoids (24 mg/kg/day) and phenolic compounds (30 mg/kg/day) extracted from Adiantum capillus for 21 days. Fasting blood glucose levels, insulin levels, insulin resistance, serum amylase levels, C-peptide levels, liver function and renal function were monitored. Results: The use of an Adiantum capillus aqueous extract in diabetic rats for 21 days effectively controlled blood glucose levels, elevated amylase level and improved renal and liver function. A significant decrease in blood glucose, AST, ALT, ALP and blood urea levels accompanied by significant increase in the serum amylase of diabetic rats was produced by the alkaloids extracted from Adiantum capillus. However, flavonoids and phenolic compounds did not cause any significant change in blood glucose levels. Conclusion:It can be concluded that the alkaloids extracted from Adiantum capillus are the chemical constituent that contributes to the antihyperglycemic effect of the plant.