Fig. 7.

Effects of the anti-oxidants N-acetylcysteine (NAC) and glutathione (GSH) on mechanical stress (MS)-induced immune gene expression and reactive oxygen species (ROS) production in periodontal ligament (PDL) cells. Cells were pretreated with NAC (20 mM) or GSH (5 mM) for 2 h, and then exposed to MS (12%) for 24 h. ROS production was assayed by flow cytometry. mRNA and protein expression levels were examined by reverse transcription–polymerase chain reaction (RT–PCR) and Western blotting, respectively. The bar graph shows the fold increase in protein or mRNA expression compared to control cells. *P < 0·05 versus untreated control; #P < 0·05 versus cells exposed to MS.