Evaluation of antibacterial properties of Matricaria aurea on clinical isolates of periodontitis patients with special reference to red complex bacteria

Abstract

Background: Chronic periodontitis has an interplay between different species of bacteria found in dental biofilms act a crucial role in pathogenesis and disease progression. The existing antibacterial therapy is inadequate, associated with many side effects as well as evolving multidrug resistance. Hence, novel drugs development with minimum or no toxicity is an immediate priority.

Methods: Antibacterial efficacy of ethanolic extract of Matricaria aurea was tested against clinical isolates, ie. Treponema denticol, Tannerella forsythia, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis from the patients with chronic periodontitis. Zone of inhibition, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were investigated by well diffusion method and micro broth dilution assay using alamar blue. Anti-virulence properties of the extract, which include adherence property and the biofilm formation, were investigated by adherence as well as biofilm formation assay.

Results: Matricaria aurea extract showed potent inhibitory effect against pathogenic periodontal bacteria with the significant inhibitory zone (13-23 mm), MIC (0.39-1.56 mg/ml) as well as MBC (1.56-6.25 mg/ml). The M. aurea extract was able to inhibit bacterial adhesion ranged from 30 to 45%, 35 to 63% and 55 to 80% of MIC at MIC × 0.5, MIC × 1 and MIC × 2 respectively. Significant inhibition was found in biofilm formation to all the tested periodontal bacterial strains after the treatment with various concentrations of M. aurea extract for 24 and 48hrs.

Conclusion: These results reveal for the first time that the Matricaria aurea extract might be the source of various compounds to be applied for chronic periodontitis therapy, which might draw these valuable compounds to the subsequent phase of development of the drug.

Keywords: Antibacterial activity; Biofilm; M. aurea; Periodontal disease; Red complex bacteria.

Fig. 1

M. aurea extract inhibit the bacterial adhesion. Alamar Blue based polystyrene adhesion assay was used to evaluate the effect of M. aurea on P. gingivalis, T. denticola, T. forsythia and A. actinomycetemcomitans adherence. All the tested bacterial strains were exposed to MIC × 0.5, MIC × 1 and MIC × 2 values of plant extract for 6 hrs at 37 °C. Control bars indicate all untreated bacterial strains, accepted as 0% inhibition. Results are presented from three independent experiments using means ± SD. ***p < 0.0001.

Fig. 2

M. aurea extract reduce the biofilm formation. (A) P. gingivalis and T. denticola (B) T. forsythia and A. actinomycetemcomitans, were incubated with MIC × 0.5, MIC × 1 and MIC × 2 values of M. aurea extract under biofilm growing conditions for 24 and 48 hrs. Control bars indicate all untreated bacterial strains, accepted as 0% inhibition. Results are presented from three independent experiments using means ± SD. ***p < 0.0001.

Fig. 3

Effect of M. aurea on bacterial growth kinetics. Representative bacterial strains of (A) P. gingivalis, (B) T. denticola, (C) T. forsythia, and (D) A. actinomycetemcomitans were treated with different concentrations (MIC × 0.5, MIC × 1 and MIC × 2) of ethanolic extract of M. aurea. Growth cycle of untreated organisms served as growth control. Absorbance at 610 nm was measured at regular time intervals of 2 h. Results are presented from three independent experiments using means ± SD. ***p < 0.0001.