SB 203580 (Synonyms: SB 203580; RWJ 64809)

SB 203580 is a specific inhibitor of p38-MAPK (Mitogen-activated Protein Kinase) pathway ^[1,2]. SB 203580 inhibits p38 kinase in a manner competitive with ATP with a Ki of 21 nm ^[2].

SB 203580 inhibit the proliferation of human breast cancer cell line MDA-MB-231 with the IC50 value of was 85.1 µM ^[3]. SB 203580 inhibited IL-10 production by monocytic WEHI 274.3 cells expressing WT-p38α MAPK in a dose-dependent manner with greater than 95% inhibition at 5 µm and with an IC₅₀ of 0.1µM ^[4]. IL-2-induced proliferation of primary human T cells, murine CT6 T cells, or BAF F7 B cells is prevented by the p38 MAP kinase inhibitor SB 203580 with an IC50 of 3-5µM ^[5].

SB-203580 demonstrated moderate to high clearance in all species tested in vivo, with non-linear elimination observed in the rat at plasma concentrations > 1000ng ml -1. Although good solution bioavailability was observed in non-rodents (78% in dog, 32% in monkey), lower and more variable bioavailability was observed in the rat and mouse (3-48%) ^[6]. SB 203580 treatment significantly improve the white blood cell (WBC) and platelet counts decreased significantly in the DENV-infected mice, suggesting leucopenia and thrombocytopenia, respectively ^[7].

References:
[1]. Barancik M, Bohacova V, Kvackajova J, Hudecova S, Krizanova O, Breier A: SB 203580, a specific inhibitor of p38-MAPK pathway, is a new reversal agent of P-glycoprotein-mediated multidrug resistance. Eur J Pharm Sci. 2001, 14: 29-36. 10.1016/S0928-0987(01)00139-7.
[2]. Peter R. Young, Megan M. McLaughlin, Sanjay Kumar, et al. Pyridinyl Imidazole Inhibitors of p38 Mitogen-activated Protein Kinase Bind in the ATP Site. The Journal of Biological Chemistry, 1997, 272(18): 12116-12121.
[3]. Duzgun SA, Yerlikaya A, Zeren S, Bayhan Z, Okur E, Boyaci I. Differential effects of p38 MAP kinase inhibitors SB 203580 and SB202190 on growth and migration of human MDA-MB-231 cancer cell line. Cytotechnology. 2017;69(4):711-24.
[4]. Guo, X., R.E. Gerl, and J.W. Schrader. 2003. Defining the involvement of p38alpha MAPK in the production of anti- and proinflammatory cytokines using an SB 203580-resistant form of the kinase. J. Biol. Chem. 278:22237-22242.
[5]. Lali, F. V., Hunt, A. E., Turner, S. J., and Foxwell, B. M. The pyridinyl imidazole inhibitor SB 203580 blocks phosphoinositide-dependent protein kinase activity, protein kinase B phosphorylation, and retinoblastoma hyperphosphorylation in interleukin-2-stimulated T cells independently of p38 mitogen-activated protein kinase. J. Biol. Chem.,275: 7395-7402,?2000
[6]. Ward KW, Prokscht JW, Azzaranot LM, et al. Preclinical pharmacokinetics of SB-203580, a potent inhibitor of p38 mitogen-activated protein kinase. Xenobiotica 2001; 31: 783-97
[7]. Sreekanth GP, Chuncharunee A, Sirimontaporn A, Panaampon J, Noisakran S, Yenchitsomanus PT, et al. SB 203580 modulates p38 MAPK signaling and Dengue virus-induced liver injury by reducing MAPKAPK2, HSP27, and ATF2 phosphorylation. PLoS One. 2016;11:e0149486.