Caco-2 monolayers grown on permeable filters for 21 days in bicameral Transwell chambers were incubated with control medium, medium containing cytomix (CM), a cocktail containing the pro-inflammatory cytokines, IL-1β (1 μg/ml), TNF (10 ng/ml) and IFN-γ (1000 U/ml), or medium containing CM and one of these other pharmacologic agents: ethyl pyruvate (EP; H2O2 scavenger; 10 mM): PJ34 (PARP inhibitor; 5 μM): 3-aminobenzamide (3-AB; PARP inhibition; 3 μM): FeTPPS (ONOO- decomposition catalyst; 50 μM): C-PTIO (NO• scavenger; 100 μM): PDTC (NF-κB inhibitor; 100 μM) or L-NIL (selective iNOS inhibitor; 20 μM). Permeability was expressed as the apical-to-basolateral clearance (nLcm-1 h-1) of fluorescein-labelled dextran (FD4) during the last 48 hours of incubation. Expression of occludin and ZO-1 were assessed by Western blot and immunohistochemistry.