Glucosamine Research Today is a free monthly online journal that collates and summarizes the latest research about Glucosamine, including details on chondroitin sulfate, uses, effects, benefits, arthritis.

Chondroitin and glucosamine sulfate in combination decrease the pro-resorptive properties of human osteoarthritis subchondral bone osteoblasts: a basic science study.

Kwan Tat S, Pelletier JP, Verges J, Lajeunesse D, Montell E, Fahmi H, Lavigne M, Martel-Pelletier J

ABSTRACT: Early in the pathological process of osteoarthritis (OA), subchondral bone remodelling takes place, which is related to altered osteoblast metabolism. In the present study, we explored in human OA subchondral bone, whether chondroitin sulfate (CS), glucosamine sulfate (GS), or both together affect the major bone biomarkers, OPG, RANKL, and the pro-resorptive activity of OA osteoblasts. The effect of CS (200 ug/ml), GS (50 and 200 ug/ml) or both together on human OA subchondral bone osteoblasts, in the presence or absence of 1,25 (OH)2D3 (vitamin D3; 50 nM), was determined on the bone biomarkers, alkaline phosphatase and osteocalcin; on the expression (mRNA) and production (ELISA) of bone remodelling factors, OPG and RANKL; and on the pro-resorptive activity of these cells. For the latter experiments, human OA osteoblasts were incubated with differentiated PBMC on a sub-micron synthetic calcium phosphate thin film. Data showed that CS and GS affected neither basal nor vitamin D3-induced alkaline phosphatase or osteocalcin release. Interestingly, OPG expression and production under basal conditions or vitamin D3 treatment were upregulated by CS and by both CS and GS incubated together. Under basal conditions, RANKL expression was significantly reduced by CS and by both drugs incubated together. Under vitamin D3 these drugs also showed a decrease in RANKL level, which did not, however, reach statistical significance. Importantly, under basal conditions, CS and both compounds combined significantly upregulated the expression ratio of OPG/RANKL. Vitamin D3 decreased this ratio, and GS further decreased it. Both drugs reduced the resorption activity, and statistical significance was reached for GS and when CS and GS were incubated together. Our data indicate that CS and GS do not overly affect cell integrity or bone biomarkers. Yet, CS and both compounds together increase the expression ratio of OPG/RANKL, suggesting a positive effect on OA subchondral bone structural changes. This was confirmed by the decreased resorptive activity for the combination of CS and GS. These data are of major significance, and may help to explain how these two drugs exert a positive effect on OA pathophysiology.

Published 12 November 2007 in Arthritis Res Ther, 9(6): R117.
Full-text of this article is available online (may require subscription).

© 2004-2008 Glucosamine Research Today. All Rights Reserved.