Chemical Composition, Antioxidant, and Antimicrobial Activities of Rosmarinus officinalis Essential Oil From Moroccan Middle Atlas

This study was designed to evaluate antioxidant and antibacterial activities of essential oils from Rosmarinus officinalis obtained by three different extraction methods: DA: Artisanal distillation; the essential oils were obtained directly from small cooperatives using a very traditional (nonindustrial) method and based on the technique of Steam distillation; DI: Industrial distillation which is also based on steam distillation; and DC: hydrodistillation through Clevenger apparatus laboratory. The chemical analyses were carried out with gas chromatography/mass spectrometry (GC/MS); they identified 16 components representing more than 99.89% of the essential oil and indicate that the chemotype is 1,8-Cineole and varies according to the method used (DI: 49.09%, DA: 42.12%, and DC: 53.21%). The antioxidant activity was evaluated by the β-carotene bleaching test measuring percent inhibition of peroxidation in linoleic acid system. The disc diffusion and modified resazurin microtiter-plate assays were used, respectively, to evaluate the inhibition zones (IZ) and minimum inhibitory concentration (MIC) of Rosmarinus officinalis essential oil. In general, Rosmarinus officinalis L. essential oil showed a lower antioxidant and antimicrobial activity than 1,8-Cineole the major component of the essential oil.