Lipoxin B4 (LXB4) is a positional isomer of LXA4 produced by the metabolism of 15-HETE or 15(S)-HpETE by human leukocytes. At a concentration of 100 nM, LXB4 inhibits polymorphonuclear leukocyte (PMN) migration stimulated by leukotriene B4 and inhibits LTB4-induced adhesion of PMNs with an IC50 value of 0.3 nM.
References:
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[3]. Papayianni, A., Serhan, C.N., and Brady, H.R. Lipoxin A4 and B4 inhibit leukotriene-stimulated interactions of human neutrophils and endothelial cells Journal of Immunology 156, 2264-2272 (1996).