Fig. 4

The effect of an NF-κB inhibitor (parthenolide) or JNK inhibitor (SP600125) on cytokine-induced cytotoxicity in A549. a Dose-response effect of parthenolide (PHL) or SP600125 (SP) on cytokine-induced cytotoxicity in A549. A549 cells were pretreated with parthenolide or SP600125 (SP) at the indicated concentration for 1 h and then stimulated with CM. Forty-eight hours after CM stimulation, cytotoxicity was evaluated by monitoring the concentration of LDH in culture medium as described in the “Methods” section. Parthenolide only slightly attenuated cytotoxicity at the maximum, nearly toxic, dose. While SP600125 suppressed cytokine-induced cytotoxicity in A549 cells in a dose-dependent manner. Bar graph shows means ± SEM. * P < 0.01 vs. CM alone. b The effects of parthenolide (PHL) and SP600125 (SP) on inflammation-associated protein expression induced by cytokines in A549 cells. Total cell lysate was collected 24 h (upper panel) or 48 h (lower panel) after CM stimulation and then subjected to western blotting using the indicated antibody. Upper panel shows selective inhibition of the NF-κB or JNK pathway was confirmed by iNOS expression or phosphorylated c-Jun (p-c-Jun), respectively. Lower panel shows SP600125(3 μM) markedly inhibited cleavage of caspase 7 and PARP, while parthenolide(15 μM) did not, although it blocked iNOS expression with this concentration