Table 2 Principal characteristics of the in vitro studies testing glucosamine
Model | Concentration | Results | Reference |
|---|---|---|---|
Glucosamine sulfate | Â | Â | Â |
   Human OA chondrocytes | 5-500 μM | Inhibition of PLA2 and collagenase in a lesser extent through PKC inhibition | [12] |
   Human OA chondrocytes stimulated with IL-1β | 10-1,000 mg/L | Inhibition of NF-κB activation Inhibition of COX-2 expression and synthesis and PGE2 release | [17] |
   Human chondrocytes stimulated with IL-1β | 10 mM | Influence of the proteomic profile | [20] |
   Human OA cartilage explants | 5 mM | Inhibition of catabolic and anabolic gene expression Superiority over glucosamine hydrochloride in the same conditions | [25] |
   Human OA osteoblasts | 200 μg/ml | Inhibition of pro-resorptive agents | [24] |
Glucosamine hydrochloride | Â | Â | Â |
   Transfected cell lines | 10 mM | Inhibition of ADAMTS-5 expression and activity | [13] |
   Human OA synovium explants | 0.5-5 mM | Induction of HA production No effect of N-acetylglucosamine | [22] |
D(+)-Glucosamine | Â | Â | Â |
   Rat chondrosarcoma cell line and | 2-16 mM | Inhibition of aggrecanase-dependent cleavage | [11] |
   bovine cartilage explants |  |  |  |
   Rat chondrocytes stimulated with IL-1β g/L | 1-4.5 | Reversion of IL-1β deleterious effect on PG anabolism | [14] |
   Rat chondrocytes stimulated with IL-1β | 4.5 g/L | Inhibition of NF-κB | [16] |
   Rat chondrocytes stimulated with IL-1β | 20 mM | Inhibition of inflammatory cytokines, chemokines and growth factors Inhibition of MMPs and aggrecanase-1 | [15] |
   Human synovial cells and chondrocytes | 0.1-1.0 mM | Stimulation of HA and GAG production Stimulation of HA synthase activity No effect of N-acetylglucosamine | [21] |
N-acetylglucosamine | Â | Â | Â |
   Human chondrocytes stimulated with IL-1β | 10 mM | Inhibition of iNOS, COX-2 and IL-6 expression | [18] |
   Human chondrocytes | 5-20 mM | Increased synthesis of GAG and HA due to acceleration of facilitated glucose uptake Superiority over native glucosamine | [26] |
   Human chondrocytes (normal and OA) stimulated with IL-1β | 2 mM | Prevention of the cytokine-induced demethylation of CpG site in the IL-1β promoter resulting in decreased expression of IL-1β | [19] |