Anxiolytic and sedative activities of Passiflora edulis f. flavicarpa

Abstract

Aim of the study: Many plants in the genus Passiflora have long been used in traditional folk medicines as a remedy for many neurogenic diseases in many countries. A number of species of the genus was studied about their neuropharmacological activities, but the results were inconsistent. No literature reported neuropharmacological studies on Passiflora edulis f. flavicarpa as yet. The present study was aimed at evaluating the anxiolytic and sedative activities of Passiflora edulis f. flavicarpa.

Materials and methods: Swiss albino mice were used as experimental animals in elevated plus-maze (EPM) test and spontaneous activity (SA) test to assay the behavioral effects of ethanolic extract (EE) of the aerial part of Passiflora edulis f. flavicarpa and its fractions, viz. petrol ether extract (PEE), ethyl acetate extract (EAE), n-BuOH extract (BE) and aqueous extract (AE), together with subfractions of BE, viz. BEF-I, BEF-II, BEF-III, BEF-IV and isoorientin, a flavonoid component isolated from BEF-III.

Results: In the EPM test, single-dose oral administration of EE (300 mg/kg and 400mg/kg), BE (125 mg/kg and 200mg/kg), AE (200mg/kg and 300 mg/kg), BEF-I (200mg/kg), BEF-II (200mg/kg), BEF-III (100mg/kg), or isoorientin (20mg/kg) resulted in anxiolytic-like effects, but a sedative-like activity was produced at higher doses, such as 300 mg/kg of BE, 200mg/kg of BEF-III, or 40 mg/kg and 80 mg/kg of isoorientin. The results of the SA test manifested that treatment with 400mg/kg of EE, 300 mg/kg of BE, or 40 mg/kg and 80 mg/kg of isoorientin compromised motor activity in mice, which are in line with the results of the EPM test.

Conclusions: The aerial part of Passiflora edulis f. flavicarpa was anxiolytic at low dose but sedative at high dose. Flavonoids are important active constituents. Since AE contained little flavonoids, it was conjectured that there were other components responsible for the anxiolytic effect of Passiflora edulis f. flavicarpa besides flavonoids.