Central nervous system depressant activity of ethanol leaf extract of Globimetula braunii (Engler) (Loranthaceae) growing on Terminalia catappa L. (Combretaceae)

Abstract

This study was carried out to determine phytochemical constituents, median lethal dose (LD₅₀) and central nervous system depressant activity of ethanol leaf extract of Globimetula braunii using laboratory animal models. The intraperitoneal median lethal dose (LD₅₀) of ethanol leaf extract of Globimetula braunii was determined in mice according to the method described by Lorke, 1983. The CNS depressant activity of Globimetula braunii leaf extract was determined using diazepam induced sleep, hole board test and beam walk assay. The ethanol leaf extract of Globimetula braunii revealed the presence of tannins, saponins, steroids, triterpenes, flavonoids and glycoside. The intraperitoneal median lethal dose of the leaf extract of Globimetula braunii was estimated to be 2852 mg/kg bodyweight in mice. The ethanol leaf extract of Globimetula braunii significantly (p <0.05) prolonged the duration of sleep in mice at the dose of 800 mg/kg. The extract prolonged the time to complete the beam walk, and exhibited significant decrease in number of head dips there by indicating a decrease in the exploratory behaviour of the animal. This study suggests that Globimetula braunii possesed sedative property.

Keywords: Beam walk assay, diazepam induced sleep, hole board test, central nervous system, Globimetula braunii