Bactericidal Activity of Mastic Against Porphyromonas gingivalis

Mastic is a resinous exudate obtained from stem and main leaves of Pistacia lentiscus. Our previous study showed mastic-essential-oil compound dentifrice was a useful anti-plaque agent in periodontal disease patients. Objectives: The aim of the present study was to assess microbiological effect of mastic-essential-oil against periodontopathic bacteria to elucidate a mechanism of anti-plaque activity of Mastic. Materials and Methods: The P. gingivalis JCM strain was used in this study. The minimum inhibitory concentration (MIC) was measured by a serial dilution assay. For ultrastructural morphological evaluation, P. gingivalis strain exposed to both Mastic and a-pinene which was a main component of Mastic, was fixed in 2.5% gluteraldehyde and postfixed in 1% osmium tetroxide. After dehydration the samples were imbedded in epon-araldide resin and polymerized. The specimens were examined the cell number and the morphology under transmission electron microscopy (TEM). Results: The MIC of Mastic against P. gingivalis was < 0.01(mg/ml). The cell number of P. gingivalis exposed a-pinene showed more than twice decrease compared to that of control (p<0.001). Morphological alterations of bacteria were seen, by TEM, in all samples examined. P. gingivalis cells showed irregular outlines and frequent detachments of the wall from cytoplasmatic membrane. Occasionally, interruptions of the wall, through which large cytoplasmatic blebs protruded, were seen. In advanced damaged organisms, enlargements and swelling of the cellular body associated with a decrease in density of the cytoplasmatic matrix were noted. Conclusion: Our results suggest that Mastic has good antibacterial activity against P. gingivalis. Further studies are needed to establish its role, in association with an antibacterial agent, in treating P. gingivalis infection: periodontal diseases.