Assessment of the Chemical/biological activities of extracts and essential oil of Rosmarinus officinalis L. from the Oriental region of Morocco

Abstract

The interest in natural conservatives, antimicrobial and antioxidants have slightly increased due to their advantageous effects. In this work bioactive compounds were obtained from Rosmarinus officinalis L. At first, the extractions of the essential oils by hydrodistillation was performed. The obtained essential oils from rosemary were yielded of about 1.8%. The GC-MS revealed that the rosemary oil was dominated by 1,8-cineol (52.440 %), Camphor (11.241 %), and α-pinene (8.225%). The extraction of the dry powders using maceration and soxhlet with solvents of different polarity showed a significant yield for ethanol compared to that of hexane. In the same context, the phytochemical screening revealed the richness of the studied plant with secondary metabolites. The antioxidant activity was assessed in vitro using scavenging activity of the free radical DPPH. It revealed that the essential oil and all ethanolic extracts tested using ascorbic acid as a reference, exhibit anti-radical activities. The ethanolic extract of Rosemary leaves showed the highest anti-radical activity (IC50 = 64.27µg/ml), followed by the extract of the latter's stems with an IC50 = 64.74µg/ml. The microbiological results showed that the antimicrobial activity was variable from one bacteria to another, this is due to the variability of the chemical composition of each extract.