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Melatonin modulates microsomal PGE synthase 1 and NF ‐ E2 ‐related factor‐2‐regulated antioxidant enzyme expression in LPS ‐induced murine peritoneal macrophages
Author(s) -
AparicioSoto M,
AlarcóndelaLastra C,
Cárdeno A,
SánchezFidalgo S,
SanchezHidalgo M
Publication year - 2014
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.12428
Subject(s) - melatonin , viability assay , p38 mitogen activated protein kinases , nitric oxide synthase , iκbα , mapk/erk pathway , nf κb , biology , chemistry , signal transduction , microbiology and biotechnology , nitric oxide , biochemistry , cell , endocrinology
Background and Purpose Increasing evidence demonstrates that melatonin regulates inflammatory and immune processes acting as both an activator and inhibitor of these responses. Nevertheless, the molecular mechanisms of its anti‐inflammatory action remain unclear. Here we have characterized the cellular mechanisms underlying the redox modulation of LPS ‐stimulated inflammatory responses in murine peritoneal macrophages by melatonin to provide insight into its anti‐inflammatory effects. Experimental Approach Murine peritoneal macrophages were isolated and treated with melatonin in the presence or absence of LPS (5 μg·mL −1 ) for 18 h. Cell viability was determined using sulforhodamine B assay and NO production was measured using the G riess reaction. Pro‐inflammatory enzymes and transcription factors were detected by W estern blotting. Key Results Without affecting cell viability, melatonin (12.5, 25, 50 and 100 μM) reduced the level of nitrites, inducible NOS ( iNOS ), COX ‐2 and microsomal PGE synthase‐1 ( mPGES1 ) protein, and p38 MAPK phosphorylation, and prevented NF ‐ κB translocation. Furthermore, melatonin treatment significantly increased NF‐E2 ‐related factor 2 ( N rf2) and haem oxygenase 1 ( HO1 ) protein levels in murine macrophages exposed to LPS . Conclusions and Implications Melatonin reduced pro‐inflammatory mediators and enhanced the expression of HO1 via NF ‐ κB , p38 MAPK and N rf2 cascade signalling pathways in murine macrophages. Thus, melatonin might be a promising target for diseases associated with overactivation of macrophages.