An in vitro evaluation of the efficacy of kaempferol as an antimicrobial agent on periodontal pathogens: An in vitro study

Abstract

Aims: Kaempferol, a flavonoid found in many edible plants, has been attributed to having antimicrobial activity against microorganisms. The current work focused on ascertaining the minimum inhibitory concentration (MIC) and conducting time-kill analysis of pure kaempferol against periodontal pathogens, along with elucidation of the antiproteolytic effect of kaempferol against Porphyromonas gingivalis protease. Method: Kaempferol dissolved in dimethyl sulfoxide was tested against six standard periodontal pathogens, namely P. gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Candida albicans, to determine the minimum bacterial concentration (MBC), MIC, and conduct time-kill analysis using serial dilution and plating method. The gelatin liquefaction test was conducted to determine the antiproteolytic activity against P. gingivalis. Results: Kaempferol was found to exhibit bactericidal activity against all analyzed periodontal pathogens. The MBC ranged from 6.25 to 100 µL/mL (P. gingivalis and P. intermedia—6.25 µL/mL; T. forsythia and C. albicans—12.5 µL/mL; F. nucleatum—50 µL/mL; A. actinomycetemcomitans—100 µL/mL). MIC ranged from 3.12 to 50 µL/mL. Time-kill analysis demonstrated that the C. albicans was inhibited by 90% within the first 2 hours of incubation and P. gingivalis and F. nucleatum by 80% within 6 hours. Complete inhibition of protease activity was established at 12.5 µL/mL concentration of kaempferol. Conclusion: The study results demonstrated kaempferol’s antimicrobial efficacy against periodontal pathogens and its ability to inhibit protease activity in P. gingivalis. Kaempferol holds promise as a safer alternative to conventional antibiotics in the treatment of periodontitis, thus expanding the therapeutic options in antimicrobial strategies.