Alpha-lipoic acid lessened cartilage damage in rats with induced osteoarthritis
This 2016 rat study found that alpha-lipoic acid, given for 14 days, lessened cartilage damage in rats with chemically induced osteoarthritis, most clearly at the highest dose. It raised gene activity for collagen type II and aggrecan and lowered markers of oxidative damage, inflammation and cell death.
What they did
Fifty male Sprague-Dawley rats were split into five groups: a sham group, an untreated osteoarthritis group, and three groups given alpha-lipoic acid (ALA) at 50, 100 or 200 mg/kg. Osteoarthritis was induced with injections of monosodium iodoacetate, a chemical that damages cartilage.
After 14 days of treatment, the researchers examined the joints by eye and under the microscope and measured markers of cartilage cell type, cell death, oxidative stress, endoplasmic reticulum stress (a form of stress inside the cell's protein-making machinery) and inflammation.
What they found
ALA, especially at 200 mg/kg, significantly lessened cartilage damage. It raised gene levels of collagen type II and aggrecan, the main building blocks of cartilage, and held back proteins involved in cell death.
It also lowered markers of oxidative damage and of two oxidant-producing proteins, Nox4 and p22phox, reduced endoplasmic reticulum stress, and dampened the NF-kB inflammatory pathway, TNF-alpha release and Wnt/beta-catenin signalling.
What it can't tell us
Rats are not people, and osteoarthritis caused by a chemical injection is a laboratory model, not the same as age-related osteoarthritis in people. The treatment lasted 14 days. The abstract does not say how the ALA was given or how often. It does not report glutathione measurements.
Why it matters
This is animal evidence that alpha-lipoic acid can protect cartilage in a model of osteoarthritis, with less oxidative damage among the effects. Taken with Han 1997, which showed how lipoic acid helps cells make glutathione, it suggests one possible route, but this study did not test whether glutathione was involved.
The paper
- Wang J, Sun H, Fu Z et al. Chondroprotective effects of alpha-lipoic acid in a rat model of osteoarthritis. Free Radic Res 2016.
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