Figure 6

Ketotifen fumarate reduced collagen density and dermal thickness in the skin in a mouse model of bleomycin-induced skin fibrosis. Two groups of mice underwent bleomycin-induced skin fibrosis for 21 days with or without ketotifen (0.00088 mg/day) supplemented in drinking water (A). Representative images of bleomycin-treated skin are shown after Masson’s Trichrome histological staining for collagen, with bleomycin and regular water on the left (B) and bleomycin with oral ketotifen on the right (C). Collagen density of bleomycin-treated skin was measured, normalized to respective saline-treated skin from the same mouse, and then plotted (D), showing a significant decrease in ketotifen-treated fibrotic skin. Dermal thickness was measured from haematoxylin and eosin-stained skin sections and represented as scar elevation index (E). Representative skin sections stained with a picrosirius red staining kit are shown under brightfield microscopy (F, top row) and birefringence imaging (F, bottom row) settings. The ratio of yellow-orange and green fibres were measured as expressed as percent of stained collagen (F, right). Data shown as mean ± SEM. n = 5–6 per experimental group. **p < 0.01.