Attenuation of IL-1ß on the use of glucosamine as an adjuvant in meloxicam treatment in rat models with osteoarthritis

Osteoarthritis (OA) is the most prevalent joint disease and a common cause of joint pain, functional loss, and disability. The severity of this disease is always associated with increased levels of proinflammatory cytokines, which play an important role in cartilage damage, synovitis, and other damage to joint tissues. The discovery that many soluble mediators such as cytokines or prostaglandins can increase the production of matrix metalloproteinases by chondrocytes led to the first steps of an inflammatory state. Several studies show that cytokines, such as interleukin 1ß, have a major role in the development of inflammation that occurs in these joints. The use of glucosamine as an adjuvant to meloxicam therapy is expected to inhibit the development of inflammatory OA. The OA model in rat was induced by single injection of intraarticular monosodium iodoacetate (MIA). The development of OA was observed for 21 days. Furthermore, the evaluation of glucosamine potency as an adjuvant of meloxicam therapy for reducing IL-1ß was done by combined treatment at a low dose of meloxicam 1 mg/kg BW with glucosamine at a dose of 125, 250, or 500 mg/kg BW orally for 28 days. Response to hyperalgesia and knee joint diameter was measured on days 0, 7, 14, 21, 28, 35, 42, and 49. IL-1ß levels were measured on day 21 and day 49 after MIA injection. MIA injection successfully induced OA as marked by a significant difference in the time of latency to heat stimulus (p < 0.01) and a significant increase in joint diameter (p < 0.01). On day 21, IL-1ß levels showed a significant decrease in MIA injection (p = 0.05). The administration of meloxicam and glucosamine did not induce significant decrease in knee joint diameter (p > 0.10), but was able to significantly increase the latency time to heat stimulus (p < 0.01). IL-1ß levels also showed a significant decrease after administering a combination of glucosamine and meloxicam (p < 0.01). Taken together, the use of glucosamine as an adjuvant in meloxicam therapy may be caused by the synergistic mechanism of meloxicam for the attenuation of OA development through systemically reducing IL-1ß.