Compositional analysis and in vitro protective activity against oxidative stress of essential oils from egyptian plants used in traditional medicine.

The Sinai desert in Egypt contains great variability in plants extensively used for traditional medicines such as Achillea fragrantissima, Chiliadenus montanus, Mentha longifolia and Haplophyllum tuberculatum. The essential oils extracted by hydrodistillation from the aerial parts have been analyzed. Subsequently, their potential protective activity against oxidative stress has been evaluated, employing H2O2 as oxidant inductor and astrocytes as the cell model. The chemical composition of the essential oils was analyzed by GC/MS. Most of the compounds identified in A. fragrantissima and M. longifolia samples were oxygenated monoterpene derivatives, whereas for H. tuberculatum they were monoterpenes hydrocarbons and oxygenated compounds, and for C. montanus oxygenated monoterpenes and oxygenated sesquiterpenes predominated. The in vitro evaluation of antioxidant properties, using ORAC assay, revealed that M. longifolia essential oil possessed the highest scavenging activity against peroxyl radicals, following by H. tuberculatum, A. fragrantissima and C. montanus. Under oxidative stress conditions, M. longifolia and H. tuberculatum essential oils were the only ones that protected human astrocytoma U373-MG cells against H2O2 damage. Both essential oils prevented cell death and inhibited ROS production caused by H2O2. M. longifolia essential oil was the most active, suggesting an interesting prevention role in those CNS disorders associated with oxidative stress.