Background: The plant species Rosmarinus officinalis (RO), Thymus algeriensis (TA) and
Thymus capitatus (TC) are widely used in traditional medicine in Tunisia. Their bioactivities have
been reported before and particularly referred to their essential oils. The main objective of this work
was to assess the phytochemical composition, the antioxidant activity, the antibacterial, antifungal, and
cytotoxic potential of these 3 plants.
Methods: The High Performance Liquid Chromatography (HPLC), chemical tests and spectrophotometric
methods were used for screening, quantification of phytochemicals and for antioxidant activities.
Extracts were evaluated for antibacterial potential by the microdilution method. Antifungal activities
were tested using the Poisoned food method against: Aspergillus niger and Aspergillus flavus. The
cytotoxic potential of the plant extracts was checked using HCT 116 cultures.
Results: Results revealed that aqueous extracts are not toxic compared to the methanolic extracts. Phenolic
compounds were detected and these extracts showed excellent antioxidant activity presenting
dose-dependent relationship. For antibacterial potential, all tested strains are more sensitive to Thymus
extracts than Rosmarinus extracts. However, for antifungal activities, only Rosmarinus extracts inhibited
mycelial growth. HPLC analysis allowed the identification of ten compounds with the abundance
of gallic acid.
Conclusion: This study showed important bioactivities (antioxidant, antimicrobial, and safety potential)
of the plant species RO, TA and TC used in traditional medicine.