High-Level Antimicrobial Efficacy of Representative Mediterranean Natural Plant Extracts against Oral Microorganisms

Abstract

Nature is an unexplored reservoir of novel phytopharmaceuticals. Since biofilm-related oral diseases often correlate with antibiotic resistance, plant-derived antimicrobial agents could enhance existing treatment options. Therefore, the rationale of the present report was to examine the antimicrobial impact of Mediterranean natural extracts on oral microorganisms. Five different extracts from Olea europaea, mastic gum, and Inula viscosa were tested against ten bacteria and one Candida albicans strain. The extraction protocols were conducted according to established experimental procedures. Two antimicrobial assays—the minimum inhibitory concentration (MIC) assay and the minimum bactericidal concentration (MBC) assay—were applied. The screened extracts were found to be active against each of the tested microorganisms. O. europaea presented MIC and MBC ranges of 0.07–10.00 mg mL−1 and 0.60–10.00 mg mL−1, respectively. The mean MBC values for mastic gum and I. viscosa were 0.07–10.00 mg mL−1 and 0.15–10.00 mg mL−1, respectively. Extracts were less effective against C. albicans and exerted bactericidal effects at a concentration range of 0.07–5.00 mg mL−1 on strict anaerobic bacteria (Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Parvimonas micra). Ethyl acetate I. viscosa extract and total mastic extract showed considerable antimicrobial activity against oral microorganisms and could therefore be considered as alternative natural anti-infectious agents.

A Preliminary Investigation on the Antimicrobial Activity of Listerine®, Its Components, and of Mixtures Thereof

“…The minimum inhibitory concentration (MIC) tests were conducted according to the Clinical and Laboratory Standards Institute guidelines as described previously (Al‐Ahmad et al , . Karygianni et al , ). The following individual Listerine® components were tested: MS (Sigma–Aldrich, Buchs, Switzerland, lot number BCBM5503V), M (Sigma–Aldrich, Buchs, Switzerland, lot number BCBK8909V), T (Sigma–Aldrich, Buchs, Switzerland, lot number SZBD1630V), Eu (Sigma–Aldrich, Buchs, Switzerland, lot number BCBL9035V), and ethanol (>99.8%, Sigma, Steinheim, Germany).…”

“…Stock solutions of the components were prepared in ethanol (>99.8%, Sigma, Steinheim, Germany). The minimum inhibitory concentration (MIC) tests were conducted according to the Clinical and Laboratory Standards Institute guidelines as described previously (Al- Ahmad et al, 2013. Karygianni et al, 2014.…”

The use of medicinal herbs in gynecological and pregnancy-related disorders by Jordanian women: a review of folkloric practice vs. evidence-based pharmacology

“…Hypoglycemic properties via stimulation of glucose uptake Afifi-Yazar et al 2011;Talib et al 2012;Seca et al 2014). Antimicrobial and anti-Helicobacter pylori efficacies (Karygianni et al 2014;Masadeh et al 2014). …”

Antimicrobial activity of extracts from olive and basil leaves against pathogenic microbial isolates from outpatient clinics of the Research Institute of Ophthalmology

“…Karygianni et al [27] examined the antimicrobial activity of natural plant and fruit extracts of Mediterranean origin against various microbial species. More specifically, five different extracts from olive leaves were screened against a panel of nine relevant pathogenic microorganisms, which constitute typical residents of the oral microflora, including one strain of C. albicans.…”