OBJECTIVETo evaluate the effects of carbon monoxide releasing molecule-2 (CORM-2) on experimental periodontitis in rats.

METHODSForty-two Wistar rats were divided into three groups. Rats in the normal group (NL group) did not undergo any procedure, whereas the other rats were ligatured and treated with saline solution (NaCl 0.9%) (LO group) or treated with CORM-2 (10 mg kg(-1) per day) (CO group). A 3-0 silk suture was placed around the mandibular first molars. Rats were sacrificed after 3, 7, and 10 d. Blood samples were collected from all animals for tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) analysis. Changes in alveolar bone levels were measured clinically, and periodontal tissues were histopathologically examined to assess the infiltration of inflammatory cells.

RESULTSLigature placement increased alveolar bone loss and inflammatory cell infiltration in periodontal tissue. Alveolar bone loss in CO group was significantly higher than that in NL group, but was lower than that in LO group (P<0.05). The ratio of inflammatory cell infiltration in LO group was significantly higher than that in CO and NL groups, and that in CO group was lower than in LO group (P<0.05). Serum levels of TNF-alpha and IL-1beta in the LO group were significantly higher than those in the CO and NL groups, and those in CO group were lower than in LO group (P<0.05).

CONCLUSIONSystemic administration of CORM-2 reduced periodontal inflammation and alveolar bone loss in experimental periodontitis in rats.