Effects of Tobacco Smoke Components on Human Neutrophils

         Introduction: Periodontal disease is an inflammatory process that result in the destruction of the supporting tissues of the teeth. Matrix metalloproteinases (MMPs) are a family of proteinases whose primary purpose is the degradation of the extracellular matrix. Neutrophils are believed to be the primary mediators of the host response  and are involved the production of reactive oxygen species (ROS), which are primarily released to kill the bacteria. However, the extracellular release of ROS also results in collateral damage of the surrounding tissues. Tobacco smokers have an increased risk,  incidence and severity of periodontal disease as evident by increased gingival recession, tooth loss, and periodontal destruction. Objective: To investigate the effects of four different chemicals found in tobacco smoke (2-naphthylaminethylamine, hydroquinone, acrolein and acetyldehyde) and compare them to nicotine and cigarette smoke condensate (CSC) with and without Porphromonas gingivalis (P. gingivalis) on the production of ROS from neutrophils and their release of MMP-9. Methods: Cell toxicity was determined by measuring the membrane damage induced by nicotine, CSC, 2-naphthylamine, hydroquinone, acrolein, or acetyldehyde-treated neutrophils utilizing dose responses. The chemiluminescence (CL) assays were performed to quantitate  ROS released from the neutrophils and the media was analyzed by Western blots to determine the release of MMP-9. Results:  The maximal doses that were not cytotoxic for these different chemicals on neutrophils were determined. Interestingly, acrolein and acetyldehyde were not toxic at any of the tested concentrations. P. gingivalis increased the release of the ROS. However when combined with most of the chemicals tested,  ROS production decreased significantly masking the effects of P. gingivalis. Western blots showed decreased MMP-9 release from the cells after treatment with most of the chemicals tested. Conclusion:  Tobacco smoke components used in this study has the potential of decreasing ROS activity of neutrophils toward P. gingivalis and also decreasing MMP-9 release.