title: Chondroitin sulfate improves synovitis in rabbits with chronic antigen-induced arthritis.
abstract: OBJECTIVE
  Our aim was to explore the effect of chondroitin sulfate (CS), a natural glycosaminoglycan with attributed anti-inflammatory properties, on synovitis in a rabbit model of chronic arthritis with intense systemic inflammation bolstered by endothelial lesion and atherosclerotic diet.
  
  
  METHODS
  Chronic arthritis was induced by intraarticular injections of ovalbumin in immunized rabbits. Systemic inflammation was boosted in these rabbits by receiving a hyperlipidemic diet after producing an endothelial lesion in the femoral arteries. A group of these rabbits were treated with CS (100mg/kg/day). At sacrifice, synovial membranes were isolated, and cyclooxygenase-2 (COX-2) and chemokine (C-C motif) ligand 2 (CCL2) mRNA, as well as protein expression were assayed by quantitative real-time polymerase chain reaction (RT-PCR) and western blot studies. Histological synovial examination was also carried out employing the histopathological synovitis score (Krenn scale).
  
  
  RESULTS
  CS diminished both gene expression and protein synthesis of COX-2 and CCL2, and the histopathological score of the synovial membrane, when compared to untreated rabbits. In fact, CS partially prevented the intimal layer proliferation and the inflammatory cell infiltration in the synovial membrane, which was observed in non-treated animals.
  
  
  CONCLUSIONS
  CS reduced the inflammatory response of the synovial membrane, as well as decreased the synovial histopathological lesions in our animal model. Further studies are warranted to demonstrate whether CS might be beneficial in the treatment of inflammatory arthritis.
authors.affiliation: Joint and Bone Research Unit, Fundación Jiménez Díaz, Universidad Autónoma, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Largo
authors.forename: J A
authors.initials: JA
authors.lastname: Roman-Blas
authors.forename: J
authors.initials: J
authors.lastname: Moreno-Rubio
authors.forename: O
authors.initials: O
authors.lastname: Sánchez-Pernaute
authors.forename: M J
authors.initials: MJ
authors.lastname: Martínez-Calatrava
authors.forename: S
authors.initials: S
authors.lastname: Castañeda
authors.forename: G
authors.initials: G
authors.lastname: Herrero-Beaumont
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001169:Arthritis, Experimental / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D018932:Chemokine CCL2 / Q000378:metabolism; D002809:Chondroitin Sulfates / Q000627:therapeutic use*; D002908:Chronic Disease; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004353:Drug Evaluation, Preclinical / Q000379:methods; D008264:Macrophages / Q000378:metabolism; D008297:Male; D011817:Rabbits; D013583:Synovial Membrane / Q000378:metabolism / Q000473:pathology; D013585:Synovitis / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism / Q000473:pathology
chemical_list: D000893:Anti-Inflammatory Agents; D018932:Chemokine CCL2; D002809:Chondroitin Sulfates; D051546:Cyclooxygenase 2