Herbimycin A suppresses NF‐κB activation and tyrosine phosphorylation of JAK2 and the subsequent induction of nitric oxide synthase in C6 glioma cells

Herbimycin A, a potent tyrosine kinase inhibitor, suppressed nitric oxide synthase (NOS) induced by lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma) in C6 glial cells. LPS activated NF-kappa B, and this effect was inhibited by pretreatment with herbimycin A. In addition, IFN-gamma activated the tyrosine protein kinase, JAK2, and tyrosine-phosphorylation by itself was also inhibited by herbimycin A. These results suggest that herbimycin A suppresses iNOS induction by inhibition of both NF-kappa B activation caused by LPS, and tyrosine-phosphorylation of JAK2 caused by IFN-gamma in C6 glioma cells.