Chondroitin sulfate from sturgeon bone protects chondrocytes via inhibiting apoptosis in osteoarthritis.

We have previously reported that chondroitin sulfate extracted from Sturgeon bone (CSSB) can alleviate the pain caused by osteoarthritis (OA) by reducing the expression of matrix metalloproteinases (MMPs) and inflammatory factors (IL-1, TNF-α and PGE). However, the mechanism of CSSB for treating OA remains unclear. As is generally accepted, these proteins and factors are regulated by chondrocyte apoptosis in OA. Thus, it is reasonable to hypothesize whether CSSB can inhibit cartilage degradation via regulating the process of apoptosis. In order to address this problem, chondrocytes were isolated and exposed to 1 mM hydrogen peroxide (HO)-treated to induce chondrocytes apoptosis for mimicking the OA microenvironment, and co-incubated with different concentration of CSSB (0, 50, 100, 200 and 400 μg/ml). Results showed that CSSB could increase cell survival, decrease DNA fragment rate and apoptosis rate, also protect mitochondrial and decrease the expression of caspase-3 and caspase-9. These results showed that CSSB ameliorates cartilage matrix damage via inhibiting chondrocytes apoptosis.