Chemical uncoupling does not induce cytotoxicity on concentrations that inhibit HSC in vitro activation. (A) Cytotoxic effect of mitochondrial uncouplers, as measured by fluorescence of bis-alanylalanyl-phenylalanyl-rhodamine 110, a peptide substrate of cytoplasmic peptidases. Insert shows cells treated with cycloheximide as positive control (B) Caspase 3/7 activity after treatment of cells with different concentrations of Valinomycin and FCCP on different time points. Enzyme activity was measured as described in material and methods. * indicates P < 0.05 compared to control group.