The aim of this study was to compare the in vivo effects on free radical metabolism of 2 nonsteroidal anti-inflammatory drugs (NSAIDs): tenoxicam, an oxicam preferentially cyclooxygenase-1 (COX1) inhibitor, and celecoxib, a sulfonamide selective COX-2 inhibitor. The serum levels of oxidative stress-related enzymes (ie, xanthine oxidase (XO), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px)), of a lipid peroxidation marker (malondialdehyde (MDA)), and of nitric oxide (NO) in patients with knee osteoarthritis were studied at baseline and after a 4-wk course of treatment with celecoxib (n = 11) and tenoxicam (n = 12). Celecoxib-treated patients had significant decrease in nitrite levels (p = 0.043), whereas SOD, XO, GSH-Px enzyme activities, and MDA levels did not change significantly compared to baseline. Tenoxicam-treated patients had significant decrease in nitrite levels (p = 0.036) and XO activity (p = 0.01), but their SOD, GSH-Px enzyme activities, and MDA levels were unchanged from baseline. There was significant correlation between the patients' (n = 23) Western Ontario and McMaster Universities (WOMAC) LK3.0 Osteoarthritis Index, WOMAC-pain scores, and MDA levels (r = 0.50, p = 0.014) and the patients' WOMAC-stiffness scores and XO enzyme activity (r = 0.46, p = 0.027) at baseline. Significant improvement was found in pain-VAS, patients' global assessment, and WOMAC pain, stiffness, and physical function scores in celecoxib and tenoxicam- treated groups. In summary, our study revealed that tenoxicam may have antioxidant effects, and that celecoxib and tenoxicam may reduce nitrite levels, indicating an alteration of NO pathways.
C1 Firat Univ, Fac Med, Dept Phys Med & Rehabil, Div Rheumatol, TR-23119 Elazig, Turkey.
Gaziosmanpasa Univ, Fac Med, Dept Physiol, Tokat, Turkey.
Inonu Univ, Fac Med, Dept Physiol, Malatya, Turkey.