The purpose of this study was to assess the effect of a novel chemically modified
curcumin (CMC 2.24) on NF-κB and MAPK signaling and inflammatory
cytokine production in two experimental models of
periodontal disease in rats. Experimental model I:
Periodontitis was induced by repeated
injections of LPS into the gingiva (3×/week, 3 weeks); control rats received vehicle
injections. CMC 2.24, or the vehicle, was administered by daily oral gavage for 4 weeks. Experimental model II: Diabetes was induced in adult male rats by
streptozotocin injection; periodontal breakdown then results as a complication of uncontrolled
hyperglycemia. Non-diabetic rats served as controls. CMC 2.24, or the vehicle, was administered by oral gavage daily for 3 weeks to the diabetics. Hemimaxillae and gingival tissues were harvested, and bone loss was assessed radiographically. Gingival tissues were pooled according to the experimental conditions and processed for the analysis of
matrix metalloproteinases (
MMPs) and bone-resorptive
cytokines. Activation of
p38 MAPK and NF-κB signaling pathways was assessed by western blot. Both LPS and diabetes induced an inflammatory process in the gingival tissues associated with excessive alveolar
bone resorption and increased activation of p65 (NF-κB) and
p38 MAPK. In both models, the administration of CMC 2.24 produced a marked reduction of inflammatory
cytokines and
MMPs in the gingival tissues, decreased bone loss, and decreased activation of p65 (NF-κB) and
p38 MAPK. Inhibition of these cell signaling pathways by this novel tri-ketonic
curcuminoid (natural
curcumin is di-ketonic) may play a role in its therapeutic efficacy in locally and systemically associated
periodontitis.