The comparison of Licorice Root Ethanolic Extract, Chlorhexidine and Doxycycline Antibacterial effects on Porphyromonas gingivalis-An In Vitro Study

 Periodontal disease causes the destruction of tooth supporting tissue. Anaerobic Gram-negative bacterium, Porphyromonas gingivalis is one of the causes of this disease. Recently, due to the many side effects of mouthwashes and antibiotics, herbal materials have been receiving attention. licorice plant, with the scientific name Glycyrrhiza glabra, has antiviral, antibacterial and anti-inflammatory properties. Therefore, the purpose of this laboratory study is to investigate the antibacterial effect of different concentrations of licorice root ethanolic extract compared to doxycycline and chlorhexidine on Porphyromonas gingivalis bacteria.

 After preparing Porphyromonas gingivalis(ATCC 33277) bacteria from Isfahan University of Medical Sciences and bacterial culture and preparation of the plant and extraction, 6 dilutions of the extract were prepared. The test was carried out against Porphyromonas gingivalis bacteria along with 0.2% chlorhexidine mouthwash and doxycycline 100 mg antibiotic, with two methods of disk diffusion and microdilution. Data were analyzed by Mann-Whitney and Kruskal-Wallis statistical tests in spss26 software at a significance level of 5%.

 All six concentrations had significant antibacterial properties compared to each other and to chlorhexidine and doxycycline(P=0/001). The inhibitory concentration of extract, MIC70 and MIC90, was related to 6.25 and 200 mg/ml concentrations, respectively. The inhibitory percentages of chlorhexidine and doxycycline were 82.4% and 77.8%, respectively.

 Licorice root ethanolic extract showed a very good antimicrobial effect. So that in higher concentrations, an equal or even greater effect was obtained than the chlorhexidine and doxycycline.