Antimicrobial effects of Boesenbergia pandurata and Piper sarmentosum leaf extracts on planktonic cells and biofilm of oral pathogens.

Increasing awareness of hazards associated with the use of antibiotic and chemical agents has accelerated investigations into plants and their extracts as new sources of antimicrobial agents. Therefore, this study aimed at determining the effects of oil and 95% ethanol extracts of Boesenbergia pandurata rhizomes and Piper sarmentosum leaf against four oral pathogens which were Streptococcus mutans, Lactobacillus sp., Aggregatibacter actinomycetemcomitans and Candida albicans. Employing the disc diffusion and broth microdilution methods, the results showed that B. pandurata oil (BPO) was the most effective extract against C. albicans. Time-kill assay with the BPO demonstrated killing of C. albicans at concentrations equal to 2 and 2.5 times the MIC. The times required to reach the fungicidal endpoint at 2 and 2.5 times the MIC were 60 and 44 min, respectively. In addition, our results also demonstrated that the BPO possesses potent anti-Candida biofilm activity in vitro. Therefore, the BPO could be considered as a natural antifungal agent against Candida infections and has significant potential for further investigation.