Effects of Walking Exercise and Meloxicam on MMP-13 Expression and Pain Threshold in Osteoarthritis

Osteoarthritis (OA) is a chronic joint disease driven by pro-inflammatory cytokines TNF-α and IL-1, which elevate matrix metalloproteinase (MMP) levels and impair extracellular matrix (ECM) synthesis. While NSAIDs are commonly used to manage OA, their long-term side effects highlight the need for alternative therapies. This study aims to examine the effects of walking exercise and meloxicam on MMP-13 expression and pain threshold. OA was induced in 30 Rattus norvegicus with a 2 mg Monoiodoacetate (MIA) injection in 25 L saline. The animals were randomly assigned into five groups: (K-) received saline only, (K+) received MIA only, (T) received MIA and a 10 m/minute light-intensity treadmill exercise, (TM) received MIA, a 10 m/minute light-intensity treadmill exercise, and oral meloxicam (1mg/kg), and (M) received MIA and oral meloxicam (1mg/kg). The treatments were administered as treadmill exercises (30 minutes/day, 5 days/week) for 6 weeks, and meloxicam was given orally (1 mg/kg, 5 days/week) for 6 weeks. After the 6-week treatment period, immunohistochemical analysis was performed to evaluate MMP-13 expression in joint cartilage tissue, and pain threshold were measured pre- and post-treatment using an analgesiometer. The results revealed that group T experienced a significant reduction in MMP-13 expression (p-value = 0.00) and an increase in pain threshold values (p-value = 0.00 ). These findings suggest that walking exercise can effectively suppress MMP-13 expression and increase pain threshold in OA.