In vitro antimicrobial, antioxidant and antiviral activities of the essential oil and various extracts of wild (Daucus virgatus (Poir.) Maire) from Tunisia

Essential oils are considered of great efficacity regarding the various beneficial effects on human health. The aim of this study was to analyze the composition and to investigate the antiviral, antioxidant and antimicrobial effects of wild Daucus virgatus (Poir.) Maire from Tunisia. The essential oil obtained by hydrodistillation air-dried D. virgatus in a Clevenger type apparatus was analyzed using gas chromatography and mass spectrometry (GC-FID and GC–MS). Fifty-two components representing 92.4% of the total constituents were identified. Methyl eugenol (33.0%) and β-bisabolene (13.2%) were the most predominant components. The antibacterial and antifungal activities against the pathogens: Pseudomonas aeruginosa, Bacillus subtilis, Bacillus anthracis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Candida albicans were investigated using the agar diffusion and broth microdilution methods. The lowest minimum inhibitory concentration was 625 μg mL−1 against both B. subtilis and C. albicans. Investigation of the in vitro antiviral activity of the essential oil, ethylacetate and methanolic extracts was tested against Coxsackievirus B (CV-B), a small nonenveloped single-stranded and positive-sense RNA virus of the Picornaviridae family that produce central nervous system disease frequently with acute syndromes. The reduction of viral infectivity of the extracts was determined by the plaque reduction assay. The cytotoxicity test demonstrated moderate cytotoxic effects of the crude extracts on the HEp-2 cell line. Fifty percent cytotoxic concentrations (CC50) are 543.35 and 372.7 μg mL−1 for ethylacetate and methanol respectively. Furthermore, ethylacetate and methanol extracts exhibited significant inhibitory effects against CV-B4 virus with IC50 vales of 98.16 and 60.08 μg mL−1 respectively.