title: The effects of nicotine and cotinine on Porphyromonas gingivalis colonisation of epithelial cells.
abstract: Smoking is a risk factor for development of periodontitis. Porphyromonas gingivalis is an important colonizer of the subgingival crevice and is a major pathogenic agent in the initiation and progression of severe forms of periodontal disease. However, the effect of major cigarette's derivatives on P. gingivalis is poorly understood. The purpose of this study was to determine the influence of nicotine and cotinine on bacterial colonisation to epithelial cells. KB cells monolayers and P. gingivalis ATCC 33277 were exposed to 0.1, 10 and 100 microg/mL of nicotine and cotinine concentrations. The epithelial cells were incubated for 24 h while P. gingivalis was exposed to these substances until reach early logarithmic phase. After the incubation period, P. gingivalis ability to colonize KB cells was assayed. The number of cell-associated/invasive bacteria was assessed by counting the colony-forming units. 100 microg/mL cotinine significantly increased P. gingivalis association and invasion of epithelial cells, when the bacteria was exposed to this substance (p<0.05; ANOVA-Tukey test). No other condition or drug altered the bacteria colonisation ability (p>0.05). These data indicated that cotinine may interfere with P. gingivalis ability to associate and invade the epithelial cells. Further studies are needed to investigate whether oral cells might be more susceptible to be colonized by P. gingivalis in smokers.
authors.affiliation: Department of Physiological Sciences, Area of Pharmacology, Anesthesiology and Therapeutics, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil. karicogo@hotmail.com
authors.forename: Karina
authors.initials: K
authors.lastname: Cogo
authors.forename: Bruna Maria
authors.initials: BM
authors.lastname: Calvi
authors.forename: Flávia Sammartino
authors.initials: FS
authors.lastname: Mariano
authors.forename: Gilson Cesar Nobre
authors.initials: GC
authors.lastname: Franco
authors.forename: Reginaldo Bruno
authors.initials: RB
authors.lastname: Gonçalves
authors.forename: Francisco Carlos
authors.initials: FC
authors.lastname: Groppo
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D003367:Cotinine / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects / Q000382:microbiology*; D006801:Humans; D007202:Indicators and Reagents / Q000494:pharmacology; D007624:KB Cells; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D016966:Porphyromonas gingivalis / Q000187:drug effects* / Q000502:physiology
chemical_list: D007202:Indicators and Reagents; D018722:Nicotinic Agonists; D009538:Nicotine; D003367:Cotinine