Central nervous system depressant activity of fractions of Globimetula braunii Engl. (Loranthaceae) growing on Terminalia catappa L. (Combretaceae) and isolation of lupeol

Globimetula braunii is a parasitic plant belonging to the family Loranthaceae. Traditionally, the plant has been reported to be used in the treatment of insomnia. The study was carried out to investigate the central nervous system (CNS) depressant activity of the fractions of Globimetula braunii growing on Terminalia catappa and to isolate the phytochemical compound(s) present in the most active fraction. The CNS depressant activity of all the fractions was investigated using diazepam induced sleep. The most active fraction was further subjected to the hole board test and beam walk assay. The chromatographic technique was used for the isolation of phytochemical compound. Hexane fraction significantly (p<0.05) reduced latency to sleep and prolonged the sleeping time. Both chloroform and ethylacetate fractions at highest and median doses showed significant increase in the duration of sleep compared to normal saline. The n-butanol fraction at all doses tested do not have any effect on time of onset and duration of sleep when compared with normal saline treated group. Hexane fraction significantly (p<0.05) decreased the number of head dip in a dose dependent manner and delayed the time to reach the goal box compared to normal saline treated group. Lupeol was isolated from n-hexane fraction.