Thymulin is a zinc-dependent metallopeptide hormone with immunomodulatory, anti-inflammatory, and analgesic activities.1,2 It is primarily produced by thymic epithelial cells but can be produced by macrophages and fibroblasts when exposed to extracellular stressors, such as heat or oxidative stress.2 Thymulin potentiates mitogen-induced proliferation of IL-2 receptor-positive mature T cells.3 It reduces pro-inflammatory cytokine production in rodent models of LPS- or endotoxin-induced systemic inflammation, as well as prevents myocardial inflammation in a mouse model of encephalomyocarditis virus-induced myocarditis and suppresses autoantibody production in a mouse model of reovirus-induced thyroiditis.4,5 Thymulin (0.1, 0.5, and 1 µg, i.c.v.) prevents endotoxin-induced hyperalgesia in rats.5
1.Bach, J.-F., and Dardenne, M.Thymulin, a zinc-dependent hormoneMed. Oncol. Tumor Pharmacother.6(1)25-29(1989) 2.Lunin, S.M., Khrenov, M.O., Glushkova, O.V., et al.Extrathymic production of thymulin induced by oxidative stress, heat shock, apoptosis, or necrosisInt. J. Immunopathol. Pharmacol.30(1)58-69(2017) 3.Hadden, J.W.Thymic endocrinologyAnn. N.Y. Acad. Sci.840(1)352-358(1998) 4.Santos, M.A.M., Henriques-Coelho, T., and Leite-Moreira, A.Immunomodulatory role of thymulin in lung diseasesExpert Opin. Ther. Targets14(2)131-141(2010) 5.Safieh-Garabedian, B., Ochoa-Chaar, C.I., Poole, S., et al.Thymulin reverses inflammatory hyperalgesia and modulates the increased concentration of proinflammatory cytokines induced by i.c.v. endotoxin injectionNeuroscience121(4)865-873(2003)