Figure 8: Effect of phototherapy on transcription factor Sp1 activity. The assessment of Sp1 activity was determined in supernatant (nuclear extracts) from U937 cells with the TransAM ELISA Kit. U937 cells were cultured with LPS (1 μg.mL-1) and treated or not with phototherapy (4.5 J/cm2) and then, the nuclear extracts were collected for evaluation of Sp1 activity. In another assay, one hour before the LPS, U937 cells were pretreated with 20 mM Nacetylcysteine (NAC). Twelve hours after the U937 cells stimulation with LPS the absorbance was determined at 450 nm using a microplate reader. Each bar represents mean ± S.D. of three independent experiments. Statistical differences were considered when p<0.05.