An in Vitro Study on the Antibacterial Effect of Ferula Assa-Foetida L. and Quercus Infectoria Olivier Extracts on Streptococcus Mutans and Streptococcus Sanguis

Background: From the ancient times, medicinal herbs have been regarded as efficient resources for the treatment of diseases. Among the diseases that can be treated by medicinal herbs, infectious diseases like oral ones are of notable importance. Objectives: The aim of this study was to evaluate the antibacterial effects of Ferula assa-foetida L (F. assa-foetida L.) and Quercus infectoria Olivier (Q. infectoria Olivier) aqueous and ethanolic extracts on Streptococcus mutans (S. mutans) and Streptococcus sanguis (S. sanguis). Materials and Methods: The studied plants were F. assa-foetida L. and Q infectoria Olivier. Their extracts with different concentrations of ۱۰۰, ۵۰, ۲۵, ۱۲.۵, ۶.۲۵, and ۳.۱۲۵ mg/mL were prepared in culture medium, with well diffusion method, and, for control, their antibacterial effects were compared with chlorhexidine. For each extract, the antibacterial ability was determined based on the created inhibition zone diameter in the microbial culture medium. Results: The aqueous and ethanolic extract of F. assa-foetida L. lacked the inhibitory effect against the growth of S. mutans and S. sanguis bacteria. There was a significant difference among the inhibitory zones created by dissimilar concentrations of Q. infectoria (P = ۰.۰۲۵). Also, the aqueous and ethanolic extracts’ minimum inhibitory concentration (MIC) for S. mutans bacterium was calculated to be ۱۲.۵ mg/ mL, while its value for S. sanguis bacterium was ۶.۲۵ mg/mL. Conclusions: The results of our study, regarding the observed effects based on differences in concentrations, suggest that further and more comprehensive studies should be undertaken to determine the appropriate concentration for obtaining the effect of the extract of F. assa-foetida L. and Q infectoria Olivier on S. mutans and S. sanguis