Fig. 4.

Time course of EFV and/or INH-induced peroxynitrite (ONOO⁻) generation in hepatocytes. (A) Hepatocytes were preloaded with coumarin-7-boronic acid (CBA, 100 μM) for 3 h and exposed to EFV alone (30 μM), INH alone (1000 μM), or a combination of the two. Hydroxycoumarin fluorescence generated from peroxynitrite-mediated CBA oxidation was serially recorded with a plate reader. (B) Fe-TMPyP, a peroxynitrite decomposition catalyst, was used to demonstrate the selectivity of the assay for peroxynitrite in hepatocytes exposed to EFV (50 μM) for 6 h. Data are mean ± SD of three independent hepatocyte preparations using quadruplicate wells. ^*P < 0.05 versus solvent control; ^#P < 0.05 versus EFV alone.