Artemisia herba-alba Asso. essential oil antibacterial activity and acute toxicity

Artemisia herba-alba Asso., known as the desert wormwood, is a medicinal plant and its essential oil is used in Algerian herbal medicine. In the present study the in vitro antibacterial activity against 21 bacterial strains and chemical composition of Artemisia herba-alba essential oil were investigated. The acute toxicity by determination of the median lethal dose was also studied. The results of gas chromatography/mass spectrometry analysis of the essential oil gave 19 compounds accounting for 98.7% and the major constituent was camphor with an amount of 50.7%. A significant antibacterial effect was observed with important zones of inhibition against Klebsiella oxytoca (31.3 mm) by disc diffusion method and against Acinetobacter baumannnii (47.6 mm) by microatmoshphere method. The minimum inhibitory concentration and the minimum bactericidal concentration values were ranging from 5 to 10 mg mL(-1) and 10-20 mg mL(-1), respectively. Moreover, their ratio exhibited by the essential oil was 2. The bactericidal end point was achieved after 24 h of exposure to the essential oil, for all the bacteria assayed. The oil was slightly toxic with a median lethal dose of 615 mg kg (similar to 1). The results of this study suggest that the essential oil of Artemisia herba-alba can be a source of natural antibacterial agents with potential pharmacological applications.