RESEARCH - Does melatonin play a disease-promoting role in RA?

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J Neuroimmunol. 2005 Jan;158(1-2):106-11.

Does melatonin play a disease-promoting role in rheumatoid arthritis?

Maestroni GJ, Cardinali DP, Esquifino AI, Pandi-Perumal SR.

Center for Experimental Pathology, Cantonal Institute of Pathology,

Via In Selva 24, P.O. Box 6601 Locarno, Switzerland.

The pineal neurohormone melatonin (MLT) has been widely shown to exert

an immunostimulatory and antiapoptotic role, mainly by acting on Th

cells and on T and B cell precursors, respectively. Thus, MLT might

favor or promote autoimmune diseases by acting directly on immature

and mature immunocompetent cells. In fact, preclinical and clinical

evidence point to a disease-promoting role of MLT in rheumatoid

arthritis (RA). MLT, whose concentration is increased in serum from RA

patients, may act systemically or locally in the inflamed joints. The

circadian secretion of MLT with a peak level during the night hours

might be strictly correlated with the peculiar daily rhythmicity of

the RA symptoms. In rat studies employing Freund's complete

mycobacterial adjuvant (FCA) as a model of rheumatoid arthritis,

pinealectomized rats turned arthritic and exhibited a significantly

less pronounced inflammatory response, which was restored to normal by

a low MLT dose and was aggravated by a pharmacological MLT dose, that

augmented the inflammatory and immune response. Continued

investigation will refine our understanding of these observations,

which will possibly translate into improved therapeutic approaches.

PMID: 15589043

http://www.ncbi.nlm.nih.gov/pubmed/15589043

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Not an MD