Development of an in vitro periodontal biofilm model for assessing antimicrobial and host modulatory effects of bioactive molecules.

Abstract

BACKGROUND:

Inflammation within the oral cavity occurs due to dysregulation between microbial biofilms and the host response. Understanding how different oral hygiene products influence inflammatory properties is important for the development of new products. Therefore, creation of a robust host-pathogen biofilm platform capable of evaluating novel oral healthcare compounds is an attractive option. We therefore devised a multi-species biofilm co-culture model to evaluate the naturally derived polyphenol resveratrol (RSV) and gold standard chlorhexidine (CHX) with respect to anti-biofilm and anti-inflammatory properties.

METHODS:

An in vitro multi-species biofilm containing S. mitis, F. nucleatum, P. gingivalis and A. actinomycetemcomitans was created to represent a disease-associated biofilm and the oral epithelial cell in OKF6-TERT2. Cytotoxicity studies were performed using RSV and CHX. Multi-species biofilms were either treated with either molecule, or alternatively epithelial cells were treated with these prior to biofilm co-culture. Biofilm composition was evaluated and inflammatory responses quantified at a transcriptional and protein level.

RESULTS:

CHX was toxic to epithelial cells and multi-species biofilms at concentrations ranging from 0.01-0.2%. RSV did not effect multi-species biofilm composition, but was toxic to epithelial cells at concentrations greater than 0.01%. In co-culture, CHX-treated biofilms resulted in down regulation of the inflammatory chemokine IL-8 at both mRNA and protein level. RSV-treated epithelial cells in co-culture were down-regulated in the release of IL-8 protein, but not mRNA.

CONCLUSIONS:

CHX possesses potent bactericidal properties, which may impact downstream inflammatory mediators. RSV does not appear to have bactericidal properties against multi-species biofilms, however it did appear to supress epithelial cells from releasing inflammatory mediators. This study demonstrates the potential to understand the mechanisms by which different oral hygiene products may influence gingival inflammation, thereby validating the use of a biofilm co-culture model.

• Authors: Emma Millhouse, Anto Jose, Leighann Sherry, David F Lappin, Nisha Patel, Andrew M Middleton, Jonathan Pratten, Shauna Culshaw, Gordon Ramage
• Journal: BMC oral health (BMC Oral Health) Vol. 14 Pg. 80 (Jun 28 2014) ISSN: 1472-6831 [Electronic] England
• PMID: 24972711 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Bacterial Agents
• Anti-Infective Agents, Local
• Anti-Inflammatory Agents
• CXCL8 protein, human
• Inflammation Mediators
• Interleukin-8
• RNA, Messenger
• Saliva, Artificial
• Stilbenes
• Resveratrol
• Chlorhexidine

Topics

• Aggregatibacter actinomycetemcomitans (drug effects)
• Anti-Bacterial Agents (pharmacology, toxicity)
• Anti-Infective Agents, Local (pharmacology, toxicity)
• Anti-Inflammatory Agents (pharmacology, toxicity)
• Biofilms (drug effects)
• Cell Line
• Chlorhexidine (pharmacology, toxicity)
• Coculture Techniques
• Down-Regulation
• Epithelial Cells (drug effects, microbiology)
• Fusobacterium nucleatum (drug effects)
• Host-Pathogen Interactions (drug effects, physiology)
• Humans
• Inflammation Mediators (immunology)
• Interleukin-8 (drug effects, immunology)
• Keratinocytes (drug effects, microbiology)
• Microbial Consortia (drug effects, physiology)
• Periodontal Diseases (microbiology)
• Porphyromonas gingivalis (drug effects)
• RNA, Messenger (drug effects)
• Resveratrol
• Saliva, Artificial
• Stilbenes (pharmacology, toxicity)
• Streptococcus mitis (drug effects)