Selected dietary (poly)phenols inhibit periodontal pathogen growth and biofilm formation

Abstract

Periodontitis (PD) is a chronic infectious disease mediated by bacteria in the oral cavity. (Poly)phenols (PPs), ubiquitous in plant foods, possess antimicrobial activities and may be useful in the prevention and management of periodontitis. The objective of this study was to test the antibacterial effects of selected PPs on periodontal pathogens, on both planktonic and biofilm modes of growth. Selected PPs (n = 48) were screened against Streptococcus mitis (S. mitis), Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Fusobacterium nucleatum (F. nucleatum) and Porphyromonas gingivalis (P. gingivalis). The antibacterial potential of each compound was evaluated in terms of planktonic minimum inhibitory concentration (PMIC) and planktonic minimum bactericidal concentration (PMBC) using standardized broth microdilution assays. The most active PPs were further tested for their effect on mono-species and multi-species biofilms using a colorimetric resazurin-based viability assay and scanning electron microscopy. Of the 48 PPs tested, 43 showed effective inhibition of planktonic growth of one or more test strains, of which curcumin was the most potent (PMIC range = 7.8-62.5 μg mL(-1)), followed by pyrogallol (PMIC range = 2.4-2500 μg mL(-1)), pyrocatechol (MIC range = 4.9-312.5 μg mL(-1)) and quercetin (PMIC range = 31.2-500 μg mL(-1)). At this concentration, adhesion of curcumin and quercetin to the substrate also inhibited adhesion of S. mitis, and biofilm formation and maturation. While both curcumin and quercetin were able to alter architecture of mature multi-species biofilms, only curcumin-treated biofilms displayed a significantly reduced metabolic activity. Overall, PPs possess antibacterial activities against periodontopathic bacteria in both planktonic and biofilm modes of growth. Further cellular and in vivo studies are necessary to confirm their beneficial activities and potential use in the prevention and or treatment of periodontal diseases.

The Anti-Adhesive Effect of Curcumin on Candida albicans Biofilms on Denture Materials

“…Conceptually, CUR could be delivered directly during ingestion, and then back through the blood into saliva indirectly. In Nepal and India for example, daily CUR consumption can reach up to 100 mg in Nepal and India (Shahzad et al, 2015), whereas in South Korea this may only reach 15 mg (Kwon, 2014). So delivering an antimicrobial concentration solely through a diet is not without challenges, though reaching an anti-adhesive concentration is possible.…”

“…Stock CUR was prepared immediately preceding the experiment using an non-antimicrobial concentration of dimethyl sulfoxide (DMSO) as a solvent and adjusted to < 5% v/v in RPMI-1640 medium (Sigma-Aldrich, UK; Shahzad et al, 2015). Standardized CLSI M-27A broth microdilution methodology was initially undertaken for planktonic yeast cultures in 96 well round bottomed microtitre plates (CLSI-M27-A, 2008).…”

“…Curcumin (CUR) shows safe and effective biological activities such as anti-inflammatory, antioxidant, anti-proliferation, with potential efficacy against many human diseases as suggested by animal studies (Gupta et al, 2012). Importantly, CUR displays broad-spectrum antimicrobial properties (Moghadamtousi et al, 2014), including antibacterial (Shahzad et al, 2015; Tyagi et al, 2015) and antifungal properties (Martins et al, 2009; Khan et al, 2012), as well as the ability to influence adhesive and biofilm properties (Shahzad et al, 2014, 2015). …”

“…Studies by our group have shown that CUR has the capacity to alter the adhesion of key periodontal pathogens, and impact overall biofilm formation (Shahzad et al, 2015). Parallel studies on the primary denture pathogen Candida albicans demonstrated that CUR exhibited anti-biofilm properties at high concentrations, as well as antifungal activity against planktonic and biofilm cells (Shahzad et al, 2014).…”

Antibacterial activity of curcumin (turmeric) against periopathogens - An in vitro evaluation

“…Shahzad et al [24] reported that the planktonic growth of periodontopathic bacteria, such as A. actinomycetemcomitans, F. nucleatum, and P. gingivalis, was inhibited by curcumin.…”