Neuropharmacological evaluation of the putative anxiolytic effects of Passiflora edulis Sims, its sub-fractions and flavonoid constituents

Passiflora edulis Sims together with several other plants of the genus Passiflora have been reported to possess anxiolytic properties. It has been suggested recently that flavonoids may be partly responsible for the neuropharmacological activity of these plants but there are still few data reporting the relation between the constituents of these plants and their activity. This work evaluated the anxiolytic/sedative activity of an aqueous extract of Passiflora edulis Sims and bioguided its fractionation using the elevated plus-maze model of anxiety and other complementary pharmacological tests. The aqueous extract presented an anxiolytic-like activity without any significant effect upon the motor activity whilst the total flavonoid fraction (TFF) presented an anxiolytic-like activity but compromised motor activity. Through fractionation of TFF it was possible to isolate and characterize luteolin-7-O-[2-rhamnosylglucoside] which showed an anxiolytic-like activity without compromising motor activity.