This 2007 lab study grew human cartilage cells and mesenchymal stem cells as pellets with glucosamine. At 100 µM it raised type II collagen and aggrecan, partly blocked IL-1 beta from lowering them, and inhibited MMP13 expression. High doses of 10 to 20 mM were inhibitory.
Researchers grew human mesenchymal stem cells and normal and osteoarthritic human articular chondrocytes as three-dimensional pellets in a defined medium, some stimulated with interleukin-1 beta. They added glucosamine at a range of doses and measured cartilage matrix genes and cartilage-degrading enzymes by RT-PCR, staining, sulphated glycosaminoglycan content and Western blotting. A separate set of chondrocytes was grown with serum for 11 days.
Chondrocytes grown with serum lost expression of type II collagen and aggrecan from day 3, and glucosamine brought it back by day 11. In defined medium, stem cell and chondrocyte pellets treated with 100 µM glucosamine had more type II collagen and aggrecan expression and more sulphated glycosaminoglycan than untreated pellets. High doses (10 to 20 mM) were inhibitory. Glucosamine partly blocked IL-1 beta from lowering type II collagen and aggrecan, and inhibited MMP13 expression in both chondrocytes and stem cells.
These are cells in pellets, with glucosamine added straight to the culture. The abstract does not give the number of donors. It measured MMP13 expression, not enzyme activity or collagen breakdown in tissue. It does not show what concentration reaches cartilage after a person takes glucosamine, and the inhibitory effect at high doses shows the result depends on concentration.
Unlike Dodge 2003, which measured MMP-3, this study measured MMP13 directly and found its expression fell. Read with Imagawa 2011, where MMP13 did not change, it shows the glucosamine evidence on MMP13 is mixed and depends on the conditions.
The lab evidence is thin and mixed. Glucosamine lowered MMP13 in one study of human cartilage cells and stem cells, but in another it didn't change cytokine-driven...
Yes, in lab studies. The inflammatory messenger IL-1 raised MMP13 in human cartilage and cartilage cells in several studies, and TNF-alpha did too. To switch the MMP13...