Suppressive Activity of Glucosamine Hydrochloride on Nitric Oxide Production from Synoviocytes In Vitro

Abstract

Background: Knee osteoarthritis (OA) is well known to be one of the most common joint disease in elderly people and characterized by a slowly progression of articular cartilage thinning and remodeling of the joints. Glucosamine hydrochloride (GH) and chondroitin sulfate, either alone or combined, are used for the treatment of OA and reported that these substances are favorably modify the clinical symptoms, especially pain, however, the underlying therapeutic mechanisms of these substances are not completely clear. The present study was undertaken to examine the influence of GH on the production of nitric oxide (NO), which is one of the important final effector molecules associated with OA, from synoviocytes from OA patients by an in vitro cell culture technique. Methods: Synoviocytes (1x105 cell/ml) were stimulated with 100.0 ng/ml periostin in the presence of various concentrations of GH. After 24 h, NO content in culture supernatants was examined by the Griess method. We also examined the influence of GH on transcription factor, NF-κB, activation and iNOS mRNA expression in synoviocytes 4 and 12 h after periostin stimulation, respectively. Results: Addition of GH into cell cultures caused the suppression of NO production from synoviocytes induced by periostin stimulation through the suppression of NF-κB activation and iNOS mRNA expression. The minimum concentration of GH that caused significant suppression of NO production was 1.5 mg/ml. Conclusion: These results strongly suggest that the ability of GH to suppress NO production from synoviocytes may account, at least in part, for the clinical efficacy of GH on OA.