Antimicrobial Activity of Eucalyptus globulus, Azadirachta indica, Glycyrrhiza glabra, Rheum palmatum Extracts and Rhein against Porphyromonas gingivalis.

Lena Katharina Müller-Heupt,Jonathan Groß,James Deschner,Till Opatz,Friederike D Von Loewenich,Nina Vierengel

doi:10.3390/antibiotics11020186

Abstract

Novel plant-derived antimicrobials are of interest in dentistry, especially in the treatment of periodontitis, since the use of established substances is associated with side effects and concerns of antimicrobial resistance have been raised. Thus, the present study was performed to quantify the antimicrobial efficacy of crude plant extracts against Porphyromonas gingivalis, a pathogen associated with periodontitis. The minimal inhibitory concentrations (MICs) of Eucalyptus globulus leaf, Azadirachta indica leaf, Glycyrrhiza glabra root and Rheum palmatum root extracts were determined by broth microdilution for P. gingivalis ATCC 33277 according to CLSI (Clinical and Laboratory Standards Institute). The MICs for the E. globulus, A. indica and G. glabra extracts ranged from 64 mg/L to 1024 mg/L. The lowest MIC was determined for an ethanolic R. palmatum extract with 4 mg/L. The MIC for the anthraquinone rhein was also measured, as the antimicrobial activity of P. palmatum root extracts can be partially traced back to rhein. Rhein showed a remarkably low MIC of 0.125 mg/L. However, the major compounds of the R. palmatum root extract were not further separated and purified. In conclusion, R. palmatum root extracts should be further studied for the treatment of periodontitis.

Highlights

Introduction iationsAccording to the Global Burden of Disease Study, severe periodontitis had a prevalence of nearly 10% of the global population in 2016 [1]
The minimal inhibitory concentration (MIC) of E. globulus leaf, A. indica leaf and G. glabra root extracts were lower when acetone was used as extractant compared to 70% aqueous ethanol (Table 1)
MIC of all plant extracts (4 mg/L) was found for the R. palmatum extract dissolved in 50%

Summary

Introduction

According to the Global Burden of Disease Study, severe periodontitis had a prevalence of nearly 10% of the global population in 2016 [1]. It is a chronic inflammatory disease of tooth-surrounding tissues causing soft tissue destruction and alveolar bone loss and, may lead to tooth loss [2]. It has been associated with an increased risk of all-cause mortality and several diseases such as cardiovascular disease, cancer, diabetes mellitus, psoriasis and rheumatoid arthritis [3,4,5,6,7]. Alongside being a pathogen in periodontitis, P. gingivalis may induce systemic inflammation and has been correlated with the development of systemic disorders such as cardiovascular and rheumatic disease [9].

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Conclusion