Phytochemical Analysis and Assessment of Biological Properties of Essential Oils Obtained from Thyme and Rosmarinus Species

Background: The plant species Thymus algeriensis (TA); Thymus capitatus (TC) and Rosmarinus officinalis (RO), are widely used in traditional medicine in Tunisia. The bioactivities of their essential oils have been also reported previously. The main objective of this work was to assess the phytochemical composition, the antioxidant activity, cytotoxic potential and the antibacterial, antifungal, of the essential oil (EO) of these plants. Methods: Gas chromatography–mass spectrometry (GC-MS) was used to identify and quantify the constituents of the tested EO, chemical tests and spectrophotometric methods were used for antioxidant activities and for the screening, the quantification of phytochemicals. The cytotoxic potential of the EO was checked using HCT 116 cultures. Extracts were evaluated for their antibacterial potential by the microdilution method. Antifungal activities were tested using the Poisoned food method against: Aspergillus niger and Aspergillus flavus. Results: The EO of tested plants presented several components, mainly monoterpenes and sesquiterpenes. Results revealed that T. capitatus EO is not toxic comparing to the other tested samples. Phenolic compounds were detected and this EO showed excellent antioxidant activity presenting dose dependent relationship. Regarding antimicrobial activity, T. capitatus EO, also had the highest inhibition against all tested bacteria and fungi. Conclusions: This study showed the importance of the bioactivities (antioxidant, antimicrobial, and safety potential) of EOs of the plant species TC, RO, and TA used in traditional medicine.