title: Mefenamic acid decreases inflammation but not joint lesions in experimental osteoarthritis.
abstract: Mefenamic acid is a non-steroidal anti-inflammatory drug able to control the symptoms of osteoarthritis (OA), but its effects on protection of cartilage and bone are still unclear. This study aimed to investigate whether the control of inflammation by mefenamic acid translates into decreased joint lesions in experimental OA in rats. OA was induced by injecting 1 mg of monosodium iodoacetate (MIA) into the joints of rats. The animals were treated with mefenamic acid (50 mg/kg, daily, oral gavage) either pre-MIA injection (preventive) or post-MIA injection (therapeutic). Joint swelling and hyperalgesia were evaluated at baseline and 1, 3, 14 and 28 days after induction of OA. Intra-articular lavage and kinetics of cell migration into the synovium were measured 3 and 28 days after OA induction. Histopathological analysis, Osteoarthritis Research Society International (OARSI) score, total synovium cells count, cartilage area and levels of proteoglycans in joints were also evaluated. Mefenamic acid prevented joint oedema and hyperalgesia induced by MIA in the acute phase (3 days) of the disease. In the chronic phase (28 days), preventive and therapeutic regimens decreased the number of mononuclear cells in the joint cavity. In contrast, thickening of the synovium, bone resorption, loss of cartilage and levels of proteoglycans were unaffected by mefenamic acid when it was administered either preventively or therapeutically. Thus, mefenamic acid had anti-inflammatory effects but did not reduce the progression of OA lesions, thereby indicating that it is only effective for symptomatic control of OA.
authors.affiliation: Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Grazielle C
authors.initials: GC
authors.lastname: Aguiar
authors.affiliation: Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Celso M
authors.initials: CM
authors.lastname: Queiroz-Junior
authors.affiliation: Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Giovana L
authors.initials: GL
authors.lastname: Sitta
authors.affiliation: Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Flávio A
authors.initials: FA
authors.lastname: Amaral
authors.affiliation: Department of Biochemistry and Immunology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Mauro M
authors.initials: MM
authors.lastname: Teixeira
authors.affiliation: Department of General Pathology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Marcelo V
authors.initials: MV
authors.lastname: Caliari
authors.affiliation: Department of Morphology, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Anderson J
authors.initials: AJ
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D001842:Bone and Bones / Q000187:drug effects / Q000473:pathology; D002356:Cartilage / Q000187:drug effects / Q000473:pathology; D004195:Disease Models, Animal; D007249:Inflammation / Q000188:drug therapy* / Q000473:pathology; D007596:Joints / Q000187:drug effects / Q000473:pathology; D008297:Male; D008528:Mefenamic Acid / Q000494:pharmacology / Q000627:therapeutic use*; D010003:Osteoarthritis / Q000188:drug therapy* / Q000473:pathology; D051381:Rats
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D008528:Mefenamic Acid
keywords: bone resorption; cartilage degradation; inflammation; joint lesions; mefenamic acid; osteoarthritis