Eosin treatment for psoriasis reduces skin leukocyte infiltration and secretion of inflammatory chemokines and angiogenic factors

Eosin has been traditionally employed as a topical treatment for psoriasis, but the biological mechanism of its therapeutic action has not been fully elucidated. To analyse eosin effects on psoriatic skin in vivo and keratinocytes and endothelial cells in vitro. Skin biopsies were taken from psoriatic plaques before and after a three-day eosin treatment and processed for histological analysis. Cultured human psoriatic keratinocytes and dermal endothelial cells were treated with eosin, and release of inflammatory chemokines was analysed by multiplexed bead-based immunoassay and ELISA. In patients, the three-day eosin treatment significantly reduced the number of infiltrating T lymphocytes, neutrophilic granulocytes, and dermal dendritic cells.Areduction in VEGF-A expressionwas also observed. In vitro, eosin treatment significantly decreased the release of CCL2, CCL5, and VEGF-A by keratinocytes and angiopoietin-2 by endothelial cells. Eosin treatment impacts on psoriatic inflammatory infiltrates and dampens the release of proinflammatory chemokines and angiogenic factors.