Glucosamine sulfate modulates dysregulated activities of human osteoarthritic chondrocytes in vitro.
OBJECTIVE
The efficacy of glucosamine sulfate (GS) in the symptomatic treatment of patients with osteoarthritis (OA) is suggested to be mediated by still unknown effects on the altered OA cartilage.


METHODS
Using human OA chondrocytes in culture, the effects of GS on protein synthesis, caseinase, collagenase, phospholipase A2 (PLA2) and protein kinase C (PKC) activities as well as production of nitric oxide and cyclic AMP were studied in both cells and culture medium.


RESULTS
GS significantly reduced PLA2 activity, and more modestly collagenase activity, in the OA chondrocytes in a dose-dependent manner. By contrast, PLA2 and collagenase activity of the culture medium was not modified. No effects on caseinase activity was seen. GS significantly and dose-dependently increased protein synthesis. GS did not modify nitric oxide and cAMP production but significantly increased PKC production.


CONCLUSIONS
GS modified cultured OA chondrocyte metabolism by acting on PKC, cellular PLA2, protein synthesis and possibly collagenase activation. Extrapolation of the effect to the in-vivo situation remains hypothetical but they might represent some possible mechanisms of action of the drug in human.
Piperno
M
M
Centre Hospitalier Lyon Sud, Claude Bernard University, 165 chemin du Grand Revoyet, Pierre Bénite, France.
Reboul
P
P
Hellio Le Graverand
M P
MP
Peschard
M J
MJ
Annefeld
M
M
Richard
M
M
Vignon
E
E
D002364:Caseins / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects*; D017364:Collagenases / Q000187:drug effects; D003470:Culture Media; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005944:Glucosamine / Q000494:pharmacology*; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism; D010003:Osteoarthritis / Q000378:metabolism*; D010741:Phospholipases A / Q000187:drug effects; D054467:Phospholipases A2; D014176:Protein Biosynthesis; D011493:Protein Kinase C / Q000187:drug effects
D002364:Caseins; D003470:Culture Media; D009569:Nitric Oxide; D000242:Cyclic AMP; D011493:Protein Kinase C; D010741:Phospholipases A; D054467:Phospholipases A2; D017364:Collagenases; D005944:Glucosamine