Sensory and vascular changes in a rat monoarthritis model: prophylactic and therapeutic effects of meloxicam

Objective and designThe objective of this study was to determine the ability of meloxicam prophylaxis and therapy to blunt the effect of complete Freund’s adjuvant (CFA) induced monoarthritis.Materials and methodsFirst the validity of this animal model was established by examining joint changes at multiple levels after injecting CFA into the tibio-tarsal joint. Next, meloxicam (5 mg/kg) or vehicle was administered on days 0–7 (prophylactic) and on days 7–16 (therapeutic) in separate groups of animals.ResultsThe CFA-injected joint demonstrated hallmark histological and structural changes such as pannus formation, bone remodeling, cartilage erosion and immune cell infiltration. Both prophylactic and therapeutic treatment with meloxicam effectively reduced swelling (ankle circumference), oedema and extravasation of Evans blue dye in the affected joint. Moreover, meloxicam reduced loss in range of motion and also reduced mechanical stimulus evoked pain scores. Notably, these effects persisted after discontinuing drug treatment.ConclusionThe present study provides a unique comparison of prophylactic versus therapeutic effects of meloxicam in the CFA-induced model of monoarthritis.