Background: The aim of this study was to evaluate the effects of selective cyclooxygenase-2 inhibitor, celecoxib, and omega-3 fatty acid on serum levels of interleukin 1-beta (IL-1β), osteocalcin (OC), and C-reactive protein (CRP) in experimental periodontitis.

Methods: Experimental periodontitis in rats was induced by repeated injection of purified lipopolysaccharide (LPS) derived from Escherichia coli endotoxin. Forty-seven adult male Sprague-Dawley rats were divided into five study groups as follows: saline control, LPS, LPS + celecoxib, LPS + omega-3 fatty acid, and LPS + celecoxib + omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given alone or in combination during 14 days of the experimental study period. At the end of the 2-week protocol, serum samples were obtained, and the rats were sacrificed. Serum samples were analyzed for IL-1β, OC, and CRP concentrations by enzyme-linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non-parametric tests.

Results: According to the morphometric measurements, the LPS and drug treatment groups showed significantly higher bone loss than the saline control group (P <0.05). Omega-3 fatty acid, both alone and in combination with celecoxib, revealed significantly higher IL-1β levels than LPS and celecoxib groups (P <0.05). Individual and combined administration of celecoxib and omega-3 fatty acid significantly increased OC levels compared to the LPS group (P <0.05). There were no significant differences in serum CRP levels.

Conclusions: Celecoxib and/or omega-3 fatty acid administration does not significantly influence circulating levels of CRP. The significantly increased serum OC level observed after individual and combination administration suggests that celecoxib and omega-3 fatty acid may influence bone remodeling and thereby inhibit the progression of alveolar bone resorption. However, the failure to observe any significant inhibition of bone loss in celecoxib- and/or omega-3 fatty acid-treated rats compared to the LPS group suggests that their therapeutic effect may be reduced by other factors, such as increases in serum IL-1β promoting osteoclast activity.