The anti-inflammatory mechanisms of minocycline, an antibiotic used in the
treatment of the inflammatory component of acne, are only partially underst
ood. In addition to inflammation due to cytokines (IL-1, IL-6, TNF-alpha, e
tc.), recent studies have shown that neuropeptide-mediated neurogenic infla
mmation mag play an important role in cutaneous inflammation. The purpose o
f this study was to investigate minocycline-induced modulation of cutaneous
production of alpha-melanocyte-stimulating hormone (alpha-MSH), a neuropep
tide with known anti-inflammatory activity. Two different skin models were
used: explants of inflammatory skin and reconstituted skin, both incubated
with minocycline at different concentrations and for different time periods
. Epidermal production of alpha-MSH, as evaluated by immunofluorescence and
immunoperoxidase techniques, showed increased expression in both models. T
his neuropeptide, which has an antiinflammatory activity (notably through p
roduction of IL-10, antagonism of IL-1 and inhibition of the chemotaxis of
polymorphonuclear leukocytes), thus plays a role in the anti-inflammatory a
ction of minocycline.