P199 DISPARATE EFFICACY OF COLLAGEN HYDROLYSATE AND GLUCOSAMINE ON THE EXTRACELLULAR MATRIX METABOLISM OF ARTICULAR CHONDROCYTES

Abstract

Purpose: Glucosamine has been used in the treatment of osteoarthritis (OA) for several years. More recently, collagen fragments were shown to provide a positive effect on joint health. The objective of this study was to investigate the efficacy of a specific type of collagen hydrolysate (CH) on the biosynthesis of ECM macromolecules in comparison with glucosamine sulfate (GS) and glucosamine hydrochloride (GH) in a chondrocyte culture model. Methods: Primary porcine articular chondrocytes and human femoral head chondrocytes were cultured under reduced oxygen conditions. The culture medium was supplemented with various concentrations of CH. In parallel experiments chondrocytes were treated with either GS or GH in various concentrations up to 2.5mM. At the end of the culture period the amount of cellassociated proteoglycans (PGs) and the extent of PG synthesis were quantified by measuring 35S-sulfate incorporation and by colorimetric assay. The amount of aggrecan accumulated in the ECM was determined by Western Blotting. In addition, type II collagen biosynthesis was quantified by means of ELISA technique. The results were confirmed by immunocytochemical detection of type II collagen and by analyzing the incorporation of 14C-proline into matrix proteins. Results: Supplementation of the culture medium with CH resulted in a statistically significant (p<0.05) increase of PG synthesis. The amount of cell-associated PGs was almost doubled after CH treatment, compared with the control cells. Administration of CH was also associated with increased aggrecan expression and a statistically significant (p<0.05) 1.5-fold increase of type II collagen biosynthesis. In contrast, the administration of GS or GH had no stimulatory effect on the type II collagen biosynthesis of the chondrocytes. Moreover, although slight differences could be observed between GS and GH, supplementation of glucosamine had no significant effect on the amount of cell-associated PGs, or total PG synthesis, compared to the controls. Conclusions: These results indicate a stimulatory effect of CH on the synthesis of PG and type II collagen. In contrast, GS and GH failed to stimulate the synthesis extracellular matrix (ECM) macromolecules by chondrocytes. These data suggest that CH may help reduce degenerative changes of the ECM by stimulating anabolic processes in cartilage tissue.