Figure 4.

Fas/FasL-caspase-3 pathway is responsible for H₂O₂-induced cell death, and MEL blocks the activation of this pathway. A: Gene expression levels of Fas, FasL, and caspase-3 after 2 h of treatment with H₂O₂ and/or melatonin (MEL). Asterisk indicates significant effect of MEL preventing Fas/FasL-caspase-3 pathway activation (one-way ANOVA and the Student–Newman–Keuls (SNK) test; p<0.05). B: Gene expression levels of Fas, FasL, and caspase-3 of cells pretreated with luzindole (LUZ) after 2 h of treatment with MEL and/or H₂O₂. Asterisks indicate a significant effect of a LUZ-blocking MEL-protective effect (one-way ANOVA and SNK test; p<0.05). C: Gene expression levels of Fas, FasL, and caspase-3 after 2 h of treatment with IIK7 and/or H₂O₂. Asterisk indicates a significant effect of IIK7 preventing Fas/FasL-caspase-3 pathway activation (one-way ANOVA and the SNK test; p<0.05). In all the cases, results shown as mean ± standard error of the mean (SEM; n=6).