Hypoglycemic, antihistaminic and diuretic effects of aqueous extract of Adiantum capillus.

Abstract

The use of plants for healing purposes predates human history and forms the origin of much modern medicine. Many conventional drugs originate from plant sources, a century ago, most of the few effective drugs were plant based. Adiantum capillus has long held a place in herbal medicine systems worldwide. It is prepared traditionally as an infusion for the treatment of respiratory and urinary disorders. The pharmacological activities of A. capillus infusion were evaluated in this study. The result obtained on the rabbit jejunum and bronchial smooth muscle indicated that A. capillus extract has attenuated the response to histamine, suggesting antihistaminergic mechanism in the observed effect. The extract showed no significant effect on the contraction of the jejunum and bronchial smooth muscle induced by pilocarpine. Therefore the antihistamine effect of the extract was not associated with antimuscarinic activity. A. capillus has produced a significant increase in the urine flow and urinary Na+ and K+ excretion rate in rabbits. This effect of A. capillus act at site before the distal nephron. The infusion of the plant produced a non significant slight reduction in the blood pressure without affecting the heart rate of the rabbit. The hypoglycemic effect of A. capillus extract was studied in alloxan-diabetic rabbits. The extract induced a significant hypoglycemic effect after oral administration which had similar efficacy to the hypoglycemic effects of metformin. The maximal rate of decline in blood glucose concentrations response was observed on the sixth day of the procedure.