Sodiumchondroitinsulfate, Condrosulf, is used in osteoarthritis therapy and belongs to the group of symptomatic slow-acting drugs for osteoarthritis. The aim of this study was to investigate the effects of Condrosulf on total proteoglycan synthesis and cell proliferation in human osteoarthritis and healthy juvenile bovine chondrocytes in vitro.
Chondrocytes were grown as monolayers and stimulated for 7 (human cartilage), or 4, 8 and 12 days (bovine cartilage) with different concentrations of Condrosulf (100 micrograms/ml, 500 micrograms/ml, 1000 micrograms/ml, 2500 micrograms/ml and 5000 micrograms/ml). Proteoglycan synthesis was measured by [35S]Sulfate incorporation. The cell proliferation rate was determined using a [3H]Thymidin assay. The expression of the cartilage markers aggrecan and collagen type II was assessed by Northern blot analysis.
We show that the incubation with Condrosulf did not affect proteoglycan synthesis neither in osteoarthritis, nor in healthy chondrocytes under the present culture conditions. Cell proliferation rate was also not increased by Condrosulf stimulation. The results of the Northern blot assays demonstrated a dose-dependent down regulation of aggrecan expression on mRNA level.
These data indicate a lack of direct anabolic effects of Condrosulf on the biosynthetic activity of cultured articular chondrocytes. The well known ease of clinical symptoms, such as pain or swelling under Condrosulf medication may be interpreted by an interaction with pro-inflammatory cytokines.