Vitamin E protects chondrocytes against hydrogen peroxide-induced oxidative stress in vitro.

Objective and design: This study evaluated the effect of an antioxidant, Vitamin E, on cultured chondrocytes against HO-induced damage in vitro. Material: Rat chondrocytes isolated from articular cartilage. Treatment: Chondrocytes were pretreated with either 50 or 100 μM Vitamin E or serum-free medium for 24 h followed by their exposure to 200 μM HO for 3 h. Chondrocytes without exposure to HO served as control group. Methods: The effect of Vitamin E pretreatment was evaluated by examining proteoglycan contents, nitrite levels, viability, apoptosis, and senescence of cultured chondrocytes. Results: Proteoglycan contents increased in groups treated with Vitamin E. Semi-quantitative real-time PCR data also correlated with these results and demonstrated that Vitamin E up-regulated expression of Agc1, Col2a1, and PCNA genes along with down-regulation in the expression of Col1a1 and Casp3 genes. The differentiation index improved after Vitamin E pretreatment. Nitrite levels were reduced with a corresponding increase in cell viability. Reduction in apoptosis and senescence was also observed after Vitamin E pretreatment. Moreover, a dose-dependent effect of Vitamin E was seen. In contrast to 50 μM Vitamin E, 100 μM was more potent in inducing protection of chondrocytes from HO-induced oxidative damage. Conclusion: Vitamin E reversed the oxidant-induced alterations in chondrocytes and may be a good option to pretreat chondrocytes before transplantation. [ABSTRACT FROM AUTHOR]