Melatonin as adjunctive therapy in the treatment of periodontitis associated with obesity

Aims To study the effect of adjunctive systemic administration of melatonin to standard mechanical periodontal therapy in obese rats with experimental periodontitis. Materials and methods Results In 42 Wistar rats with an initial body weight of 180 g., half (n = 21) were fed with a high-fat diet to induce obesity. In both obese and normal-weight groups, experimental periodontitis was subsequently induced through oral gavages with a combination of Porphyromonas gingivalis and Fusobacterium nucleatum. Both groups were randomly allocated to either no treatment or periodontal treatment consisting on standard mechanical debridement, with either adjunctive chlorhexidine or melatonin. Outcomes were evaluated by the changes in clinical parameters (probing depth modified gingival index, plaque dental index and bleeding on probing [BOP]), in bone resorption and in the levels of biomarkers in plasma and in gingival tissue (inflammatory cytokines, insulin, leptin, osteocalcin, osteopontin, plasminogen activator inhibitor-1, intercellular adhesion molecule 1, E-selectin and lipids). In the obese-periodontitis group, adjunctive melatonin administration resulted in reduced gingival inflammation and BOP, with significant reductions in probing depth and enhanced bone repair demonstrated by micro-CT (15% reduction in alveolar bone destruction) when compared with the same group treated with adjunctive CHX or the normal-weight rats with either melatonin or CHX. In this melatonin-treated obese-periodontitis group, a significant impact on biochemical biomarkers was also demonstrated in both gingival and plasma samples, when compared with the other groups, with significant reductions in pro-inflammatory cytokines. Conclusions Adjunctive melatonin therapy significantly reduced alveolar bone loss and exerted a protective anti-inflammatory effect mainly in those experimental animals affected by the co-morbidity of periodontitis and obesity.