Antimicrobial Activity of Angelica Dahurica Ethanol Extract Against Oral Bacteria

Introduction: Angelica dahurica (A. dahurica) has the protective activity against dexamehasone-induced disorders, liver protective activity, antimutagenic activity, anti-inflammatory, anti-microbial, anti-oxidative, anti-asthmatic, and anti-cancer effects. Aims of the Study: This study aimed to investigate the synergistic antibacterial activity with existing antimicrobial agents against oral pathogen. Materials and Methods: The synergistic effects of 50% ethanol extract of A. dahurica (ADEE) were evaluated against oral bacteria, either alone or with antibiotics, via broth microdilution and time-kill method. Results: The minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) values for ADEE, ampicillin and gentamicin against all the tested bacteria ranged between 62.5-1000/250-2000 μg/mL, 0.0625-16/0.25-32 μg/mL, and 4-128/16-256 μg/mL, respectively. The ADEE displayed synergism with ampicillin and gentamicin, with 8-fold reductions in the MIC/MBC. Furthermore, a time-kill study showed that the growth of the tested bacteria was completely attenuated after treatment with 1/2 MIC of ADEE with 1/2 MIC of antibiotics resulted from an increase of the rate of killing in units of CFU/mL to a greater degree than was observed with alone. Discussion and Conclusions: The results of this study demonstrate the antimicrobial and synergistic activity of ADEE and antibiotics against oral pathogens.