Sedative, hypothermic, anxiolytic effects and rapid radical scavenging property of aqueous leaf extract of Vitex doniana (Lamiaceae) in mice

Abstract

Vitex doniana is used ethnomedicinally for the management of madness, insanity, and epilepsy. This study was undertaken to evaluate the sedative, hypothermic and anxiolytic effects of crude aqueous leaf extract of Vitex doniana (AVD) in mice, as well as its rapid radical scavenging property. Doses of 250, 500, and 1000 mg/kg AVD were adopted for the pharmacological testing in mice of both sexes (n=6). The behavioural effects of the extract in the open field apparatus were determined. AVD was evaluated for its anxiolytic effect, using elevated T- maze, staircase, and hole-board models. While the sedative and hypothermic effects of the extract in mice were determined by assessments of ketamine-induced sleeping time and rectal temperature respectively. AVD was subjected to rapid radical scavenging test using thin-layer chromatography (TLC)-bioautography. The results showed AVD to have an inhibitory effect on CNS in the open field test. AVD demonstrated anxiolytic effect at 250 mg/kg, and sedative effect at 500 and 1000 mg/kg. The sedative effect of AVD at 500 and 1000 mg/kg was further revealed in ketamine-induced sleeping time and rectal temperature. AVD also showed strong free radical scavenging property attributed to the presence of fatty acid esters, terpenes, phenolics, and phenolic glycosides. AVD is acutely non-toxic and it possesses significant sedative, hypothermic and anxiolytic effects, which could in part be due to the presence of rapid free radical scavenging compounds, thus, providing pharmacological justification for its ethnomedicinal uses as a curative for madness and insanity.