Antibacterial activity of Miswak (Salvadora persica) extracts against isolated and genetically identified oral cavity pathogens

Abstract

BACKGROUND: Despite medical progress worldwide, dental caries are still widespread. Miswak is derived from the plant Arak (Salvadora persica). It is used by Muslim peoples as a natural product for the cleansing of teeth, to ensure oral and dental hygiene. OBJECTIVE: This study was conducted to evaluate the antimicrobial effects of ethanol, methanol, and ethanol/methanol extracts of Miswak against three bacterial pathogens of the oral cavity. METHODS: The pathogens were isolated from the oral cavity of volunteers/patients and were identified on the basis of 16S rRNA gene amplification data. Sequence comparisons were made with 16S rRNA gene sequences available in the GenBank database. RESULTS: The results of sequence alignment and phylogenetic analysis identified the three pathogens as being Staphylococcus aureus strain KKU-020, Enterococcus faecalis strain KKU-021 and Klebsiella pneumoniae strain KKU-022. All Miswak extracts showed powerful antimicrobial activity against the three pathogens. The maximum zone of inhibition (40.67 ± 0.88 mm) was observed against E. faecalis KKU-021 with ethanolic extracts whilst methanolic extracts showed the minimum zone of inhibition (10.33 ± 0.88 mm) against K. pneumonia KKU-022. CONCLUSION: Based upon the significant effects of the Miswak extracts, against the oral cavity pathogens in our study, we recommend that Miswak could be used as a dental hygiene method to prevent tooth caries.