Anxiolytic and sedative-like effects of flavonoids from Tilia americana var. mexicana: GABAergic and serotonergic participation
Date
2016
Journal Title
Journal ISSN
Volume Title
Publisher
Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz
Abstract
Description
Introduction The inflorescences of Tilia americana var. mexicana are used as an infusion in Mexican traditional medicine due to their tranquilizing effects; however, pharmacological and phytochemical studies of the leaves are lacking. Objective In this research, the anxiolytic and sedative-like efficacy of the Tilia americana var. mexicana leaves was compared to that obtained with its inflorescences and flavonoids therein identified, as well as the pos sible mechanism of action. Methods The sorted and dried inflorescences and leaves were macerated sub sequently in hexane, ethyl acetate and methanol. The methanol ex tracts were qualitative- and quantitative-analyzed by HPLC, using com mercial flavonoids standards selected on the basis of their previously reported presence in Tilia species. The pharmacological activity was evaluated in CD-1 mice in the tests: open-field, elevated plus-maze, hole-board, and the sodium pentobarbital-induced sleep potentiation test. In regard to the mechanism of action, participation of benzodi azepine and 5-HT1A serotonin receptors was tested with the respective antagonists: flumazenil and WAY100635. Results The presence of quercetin, rutin and isoquercitrin was confirmed in the extracts of the inflorescences and leaves. The anxiolytic-like effects were the same between the two organs, which were inhibited in the presence of flumazenil and WAY100635. Discussion and conclusion Our results provide evidence that the extracts of the leaves of T. amer icana var. mexicana are as efficacious as the inflorescences to pro duce anxiolytic and sedative-like effects, where flavonoids like querce tin, rutin and isoquercitrin are partially responsible for these activities by the involvement of GABA/BDZ and 5HT1A serotonergic receptors.