Curcumin modulates inflammation associated with periodontal disease in vivo

Curcumin is a yellow pigment found in the rhizome of turmeric (Curcuma longa L., Zingiberaceae) and related species, and has a wide range of pharmacological and biological activity. The antiarthritic and anti-inflammatory effects of this compound have been assessed in various in vitro and in vivo systems, but there is no information regarding its effects on the progression of periodontal disease. Objective:To evaluate the effect of systemically administered curcumin on the inflammatory response during the course of two models experimentally-induced periodontal disease in rats.Methods: Periodontal disease was induced by ligature placement on lower first molars and LPS injections on upper first molars of Wistar rats for 15 days. Curcumin was administered daily by oral gavage in two doses: 30 and 100mg/kg. The expression of inflammatory mediators IL-6, COX-2 and TNF-alpha in the periodontal tissues was assessed by RT-qPCR and ELISA. Results: Curcumin completely abrogated PGE2-synthase mRNA expression in both models. IL-6 and TNF-alpha were effectively inhibited at mRNA (30mg/kg, p=0,0065; 100mg/kg, p=0.0186) and protein levels in the ligature model. In the LPS model, even though TNF-alpha and IL-6 mRNA expression were also completely blocked, only the lower dose of curcumin significantly inhibited IL-6 at the protein level. On the other hand, TNF-alpha protein was significantly inhibited only in the animals treated with the higher dose of curcumin. Conclusion: In conclusion, our results showed that curcumin may have a potential clinical application in the modulation of inflammation associated with periodontal disease.