title: Immunomodulatory effects of melatonin in asthma.
abstract: Patients with nocturnal asthma demonstrate circadian variations in airway inflammation. We hypothesized that melatonin, a circadian rhythm regulator, modulates circadian inflammatory variations in asthma. The effect of melatonin stimulation on peripheral blood mononuclear cell cytokine production was evaluated at 4:00 P.M. and 4:00 A.M. in normal control subjects, patients with nocturnal asthma, and patients with non-nocturnal asthma. Melatonin was proinflammatory, causing significantly increased production of interleukin-1, interleukin-6, and tumor necrosis factor-alpha at 4:00 P.M. and 4:00 A.M. in all subject groups (range, 12.8 +/- 3.3 to 131.72 +/- 16.4%, p < or = 0.0003). The observed increases in cytokine production did not change between 4:00 P.M. and 4:00 A.M. in control subjects or in patients with nocturnal asthma (p > 0.05, both cases). At 4:00 P.M., the cytokine response to melatonin of patients with nocturnal asthma was greater than that of control subjects or patients with non-nocturnal asthma and did not change significantly at 4:00 A.M. At 4:00 P.M., the cytokine response of patients with non-nocturnal asthma was less than that of patients with nocturnal asthma and rose significantly at 4:00 A.M. (p = 0.0001, all comparisons). Melatonin is proinflammatory in both patients with asthma and healthy subjects. Patients with nocturnal asthma demonstrate the largest daytime cytokine response and cannot be further stimulated at 4:00 A.M., suggesting chronic overstimulation in vivo. These results suggest differential immunomodulatory effects of melatonin based on asthma clinical phenotype and may indicate an adverse effect of exogenous melatonin in asthma.
authors.affiliation: Department of Medicine, National Jewish Medical and Research Center, Denver, CO, USA. sutherlande@njc.org
authors.forename: E Rand
authors.initials: ER
authors.lastname: Sutherland
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Martin
authors.forename: Misoo C
authors.initials: MC
authors.lastname: Ellison
authors.forename: Monica
authors.initials: M
authors.lastname: Kraft
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000328:Adult; D001249:Asthma / Q000276:immunology*; D002455:Cell Division; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D008297:Male; D008550:Melatonin / Q000276:immunology* / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D000276:Adjuvants, Immunologic; D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D008550:Melatonin