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

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.