title: Low-dose doxycycline prevents inflammatory bone resorption in rats.
abstract: Matrix metalloproteinases (MMP) are considered to be key initiators of collagen degradation, thus contributing to bone resorption in inflammatory diseases. We determined whether subantimicrobial doses of doxycycline (DX) (< or =10 mg kg-1 day-1), a known MMP inhibitor, could inhibit bone resorption in an experimental periodontitis model. Thirty male Wistar rats (180-200 g) were subjected to placement of a nylon thread ligature around the maxillary molars and sacrificed after 7 days. Alveolar bone loss (ABL) was measured macroscopically in one hemiarcade and the contralateral hemiarcade was processed for histopathologic analysis. Groups of six animals each were treated with DX (2.5, 5 or 10 mg kg-1 day-1, sc, 7 days) and compared to nontreated (NT) rats. NT rats displayed significant ABL, severe mononuclear cell influx and increase in osteoclast numbers, which were significantly reduced by 5 or 10 mg kg-1 day-1 DX. These data show that DX inhibits inflammatory bone resorption in a manner that is independent of its antimicrobial properties.
authors.affiliation: Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Rua Cel. Nunes de Melo 1127, 60430-270 Fortaleza, CE, Brazil.
authors.forename: M M
authors.initials: MM
authors.lastname: Bezerra
authors.forename: G A C
authors.initials: GA
authors.lastname: Brito
authors.forename: R A
authors.initials: RA
authors.lastname: Ribeiro
authors.forename: F A C
authors.initials: FA
authors.lastname: Rocha
mesh_terms: D016301:Alveolar Bone Loss / Q000517:prevention & control*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004318:Doxycycline / Q000008:administration & dosage / Q000627:therapeutic use*; D007568:Jaw; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors; D010518:Periodontitis / Q000188:drug therapy* / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000900:Anti-Bacterial Agents; D061965:Matrix Metalloproteinase Inhibitors; D004318:Doxycycline