This 2016 study tested vitamin C in SW1353 cells, a cartilage tumour cell line, and in rats with chemically induced joint damage. In the cells, 100 µM vitamin C stopped the rises in MMP-1, MMP-3, MMP-13 and inflammatory cytokines. In rats it lessened cartilage changes, and 100 mg/kg worked better than 200 or 300 mg/kg.
Researchers exposed SW1353 chondrosarcoma cells to 5 µM monosodium iodoacetate (MIA), which damages cartilage cells, with or without 100 µM vitamin C. They measured cell growth, oxidative stress, cell death, proteoglycan loss, inflammatory cytokines and MMPs. In rats, they injected MIA into the joint and gave vitamin C at 100, 200 or 300 mg/kg.
In the cells, MIA slowed growth, raised oxidative stress, cell death and proteoglycan loss, and raised IL-6, IL-17A, TNF-alpha, MMP-1, MMP-3 and MMP-13. Vitamin C at 100 µM stopped all of these changes. In the rats, vitamin C lessened the cartilage damage MIA caused. Unexpectedly, the effect did not grow with dose: 100 mg/kg was more effective than 200 or 300 mg/kg.
SW1353 is a cartilage tumour cell line, which behaves differently from normal cartilage cells. The abstract does not say how vitamin C was given to the rats, for how long, or how many rats were used. Rat doses per kilogram do not translate directly to people, and the study does not show what vitamin C intake does to MMP13 in a human joint.
It looks at vitamin C on the breakdown side of cartilage: it held back the enzymes that cut the matrix, MMP-13 among them, along with inflammatory cytokines. The lowest dose working best in rats is a reminder that more is not always better in these studies.
In human cartilage cells, MMP13 rose in response to inflammatory messengers such as IL-1, oxidative stress, calcium phosphate crystals, a disrupted cell body clock...
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...