Antibacterial Activity of Different Artemisia dracunculus Extracts Against Dental Caries-Related Pathogens

 This study investigated the antibacterial properties of four types of tarragon (Artemisia dracunculus) extracts against two caries contributing bacteria, namely, Streptococcus mutans and Streptococcus sobrinus.

 The extracts of A. dracunculus were prepared using n-hexane, ethyl acetate, methanol, and water solvents. In addition, the diameter of inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs) were determined, and finally, MTT (tetrazolium-based colorimetric assay) was used to analyze the cytotoxic effects of the extracts.

 The well-diffusion method showed the antibacterial property of four tested extracts against bacteria. Methanol and water extracts made the highest inhibition zone diameters (P<0.001). This was true for both tested bacteria. The mIC of the methanol, water, n-hexane, and ethyl acetate extracts were 0.78, 1.5, 3.1, and 1.5 mg/mL, as well as 0.78, 0.78, 1.5, and 1.5 mg/mL against S. mutans and S. sobrinus, respectively. The half-maximal inhibitory concentration (IC50) values for methanolic, aqueous, ethyl acetate, and n-hexane extracts were 0.78, 0.78, 1.56, and 3.12 mg/mL, respectively.

 The results provided a rational reason for the traditional use of A. dracunculus extracts against anti-caries-related bacteria. The methanolic extract demonstrated better activity, thus methanol can probably extract a wider range of plant compounds with antibacterial effects.