The objective of the study was to investigate the possibility of modulation of skin
inflammation by topical treatment with a novel compound: an
opioid-
neurotensin hybrid
peptide PK20 encompassing
endomorphin-2 analog and modified fragment of
neurotensin (8-13).
Contact sensitivity response was induced in mice by skin sensitization with
dinitrofluorobenzene (
DNFB) followed by topical
hapten application on ears. Mice were treated locally with PK20 or pure cream 2h after the challenge with
DNFB. 2 and 24h after
hapten exposure, ear thickness was determined. Ears were collected for histology and homogenization. Supernatants were used for measurement of contents of
cytokines and lipid peroxidation products. Treatment with PK20 reduced significantly the late phase of
contact sensitivity response, which was revealed by ear thickness diminution and reduction of inflammatory cell infiltration. The average concentrations of IL-1α, MCP-1, TNF-α and
thiobarbituric acid-reactive substances were significantly decreased in the ears treated with the chimera in comparison to the control cream treated ears in
DNFB sensitized/
DNFB challenged group. We found that PK20 topical treatment alleviates
hypersensitivity responses triggered by
DNFB challenge and usage of the hybrid
peptide may be a novel therapeutic strategy in the treatment of chronic inflammatory diseases. However, the mechanism remains unclear and needs further investigation.