Anti-anxiety studies on extracts of Passiflora incarnata Linneaus.

Passiflora incarnata Linn. has been used to cure anxiety and insomnia since time immemorial. Despite the worldwide use of P. incarnata, the pharmacological work on this plant had been inadequate, inconclusive and wage as the earlier reports were unable to infer the mode of action of the plant as well as the phytoconstituents responsible for the much acclaimed anxiolytic and sedative effects of P. incarnata. An attempt has been made to isolate and identify the bioactive phytomoiety of P. incarnata by resorting to bioactivity directed fractionation and chromatographic procedures. A fraction derived from the methanol extract of P. incarnata has been observed to exhibit significant anxiolytic activity at a dose of 10 mg/kg in mice using elevated plus-maze model of anxiety. This fraction comprises mainly two components which are visible as blue and turquoise colored fluorescent spots at 366 nm of the UV light. The possibility of a phytoconstituent having benzoflavone nucleus as the basic moiety being responsible for the bioactivity of P. incarnata is highly anticipated.