Evaluation of antibacterial efficacy of Lawsonia inermis Linn (henna) on periodontal pathogens using agar well diffusion and broth microdilution methods: an in-vitro study

Background : Although widely explored in medicine, limited evidence exists in the literature regarding the ef fi cacy of Lawsonia inermis Linn (henna) in the dental fi eld. Aim : This study aimed to investigate the antibacterial effect of henna on Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in vitro. Methods : The agar well diffusion and broth microdilution methods were used to evaluate the antibacterial effect of henna extracts. Dimethyl sulfoxide was used to prepare the ethanol extract of henna, and distilled water was used to prepare the water extract. For both ethanol and water extracts, 4 different concentrations were prepared as 15, 30, 60, and 120 mg/mL. Results : It was determined that the water and ethanol extracts of the henna samples did not show an inhibition zone on P.gingivalis and A.actinomycetemcomitans. As a result of the evaluations made with the broth microdilution method, it was found that the ethanol extract had a higher inhibitory effect on both bacteria, and both extracts had more inhibitory effects against A.actinomycetemcomitans. Conclusion : To understand the effect of henna on periodontal pathogens, more comprehensive in vitro studies should be performed on henna samples at different concentrations and with different bases.