Anti-bacterial effect of white tea extract on Streptococcus mutans and Streptococcus salivarius

Abstract

Due to the increasing frequency of drug-resistant strains among different types of microorganisms, the finding of antimicrobial and antifungal compounds of natural substances, which certainly has fewer side effects, has long been of interest to researchers. Therefore, the aim of this investigation was to study the effect of white tea extract on reducing Streptococcus mutans and Streptococcus salivarius. White tea was prepared in powder form and then its hydroalcoholic extract of it was prepared. The antimicrobial effects of extracts on S. mutans and S. salivarius were performed using well diffusion and broth microdilution methods. All experiments were performed in triplet replications. Antibacterial susceptibility testing revealed that white tea extract at concentration of 500 µg/ml had a remarkable antibacterial activity against S. mutans, and S. salivarius with a zone of inhibition, 25±1 mm and 30±1, respectively. The minimum inhibitory concentration (MIC) values of the both tested strains were estimated 31.25 µg/ml. Moreover, the minimum bactericidal concentration (MBC) values of white tea extract were estimated 62.5 µg/ml against both streptococci. Considering the inhibitory power of the white tea extract on the gram-positive bacteria of S. salivarius and mutans, it can be concluded that this plant can be used in various industries, including the pharmaceutical and sanitary industry and it can also improve oral health as S. mutans and salvarius are the most important bacteria causing decays.