α-tocopherol decreases interleukin-1β and-6 and increases human β-defensin-1 and-2 secretion in human gingival fibroblasts stimulated with Porphyromonas gingivalis lipopolysaccharide

Background and Objective: Periodontitis, a disease associated with chronic inflammation, results in significant destruction of periodontal tissues. Uncontrolled, periodontal disease negatively affects general patient health. We sought to evaluate the effect of alpha-tocopherol on gingival fibroblast behavior following exposure to Porphyromonas gingivalis lipopolysaccharide (LPS). Material and Methods: Primary human gingival fibroblasts were cultured for 24 and 48 h with alpha-tocopherol at various concentrations (0, 50, 100 and 200 mu m) in the presence or absence of 1 mu g/mL of LPS. At the end of each time point, cell adhesion and growth were evaluated by means of optical microscope observations and MTT assay. The secretion levels of cytokines interleukin (IL)-1 beta and IL-6 and human beta-defensins 1 and 2 were measured by specific enzyme-linked immunosorbent assay. Finally, an invitro scratch wound assay was performed to investigate the effect of alpha-tocopherol on fibroblast migration. Results: alpha-tocopherol alone had no adverse effect on cell adhesion and morphology. Fibroblast proliferation increased in the presence of alpha-tocopherol with and without LPS. alpha-tocopherol alone had no effect on inflammatory cytokine (IL-1 beta and IL-6) secretion. Interestingly, following cell exposure to P.gingivalis LPS, alpha-tocopherol significantly (p<0.01) decreased the secretion of these two cytokines and increased human beta-defensin-1 and -2 secretion. Finally, alpha-tocopherol increased the healing rate of the gingival fibroblasts from 12h up to 48h. Conclusion: These results suggest that alpha-tocopherol may play an active role in countering the damaging effect of LPS by reducing inflammatory cytokines, increasing -defensins and promoting fibroblast growth, migration and wound healing.