Behavioural activities and chemical composition of fresh leaf essential oil of Plectranthus aegyptiacus from Southwest Nigeria in mice

Objectives: This study determined the chemical composition of essential oil obtained from fresh leaf Plectranthus aegyptiacus, and evaluated it for novelty-induced behavioural (NIB) determine its mechanism(s) action in mice. Methods: The was hydro-distillated, analyzed using gas chromatography-mass spectrometry. effects (50, 100 150 mg/kg; i.p., n=6) on assessed open field test head dipping hole board. Probable were antagonists: flumazenil, naloxone cyproheptadine at 2 mg/kg each, atropine yohimbine 5 1 respectively. Key Findings: LD50 values 2154 490 oral intraperitoneal routes and150 mg/kg) significantly (p<0.05, 0.01 0.01) inhibited all NIB dips. Flumazenil (p<0.05) reversed effect NIB; atropine, (p<0.01, 0.001) potentiated inhibitory respectively, while showed no effect. 61 compounds, major compounds carvacrol, germacrene-D, p-cymene [1,1'-Bicyclopentyl]-2,2'-diol. Conclusions: concluded that possessed central nervous system depressant activity, which could be mediated mainly through augmentation GABAergic neurotransmission, cholinergic-(muscarinic), adrenergic serotonergic pathways may involved.