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Melatonin enhances pro‐inflammatory cytokine levels and protects against Chagas disease
Author(s) -
Santello Fabricia Helena,
Frare Eduardo Osório,
Caetano Leony Cristina,
AlonsoToldo Míriam Paula,
Do Prado José Clóvis
Publication year - 2008
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.2008.00558.x
Subject(s) - melatonin , immune system , immunology , cytokine , trypanosoma cruzi , tumor necrosis factor alpha , biology , macrophage , interleukin , proinflammatory cytokine , inflammation , endocrinology , in vitro , parasite hosting , biochemistry , world wide web , computer science
Pro‐inflammatory and modulatory cytokines have an essential role in host defense against human and murine Trypanosoma cruzi infection. Control of T. cruzi parasitism during the acute phase of infection is considered to be critically dependent on direct macrophage activation by cytokines. Melatonin has been proposed to regulate the immune system by affecting cytokine production in immunocompetent cells, enhancing the production of several T helper (Th)1 cytokines. The aims of this work were to evaluate in rats, the influences of exogenous melatonin treatment on T. cruzi‐ infected host’s immune responses. With this in mind, several immunological parameters were analyzed, including tumor necrosis factor‐α, γ‐interferon, interleukin‐12, nitric oxide (NO) and macrophage count. The melatonin therapy was provided in one of two different treatment regimens, that is, either beginning 7 days prior to infection or concomitant with the infection. Both treatments triggered an up‐regulation of the immune response, with the concomitant treatment being more effective; in this case all cytokines studied, with exception of NO, displayed enhanced concentrations and there was a higher number of peritoneal macrophages, which displayed reduced concentrations under melatonin therapy. We conclude that melatonin plays a pivotal role in up‐regulating the Th1 immune response thus controlling parasite replication.