N-acetyl cysteine protects TMJ chondrocytes from oxidative stress

Temporomandibular joint (tmj) inflammation is closely associated with oxidative stress. this study tested the potential of n-acetyl cysteine (nac),an anti-oxidant amino-acid derivative,in alleviating oxidative stress-related damage in tmj chondrocytes. the inflammatory condition was simulated by the addition of hydrogen peroxide (h2o2) to tmj-derived chondrocyte cultures. exposure to h2o2 decreased the cell population by half within 2 days as a result of induced apoptosis and reduced proliferation. gene expression of aggrecan and collagen ii,as well as glycosaminoglycan production,were reduced by more than 70%. these compromised chondrocyte viability and function were fully restored by the addition of nac to the cultures. nac reduced the h2o2-elevated intracellular reactive oxygen species to the normal level and increased cellular glutathione reserves. these results indicate that nac restores oxidative stress-induced cell death and severe functional impairment in tmj chondrocytes,and warrant in vivo testing to explore its therapeutic potential as an anti-inflammatory agent. © international & american associations for dental research.