FIGURE 6.

Osthole prevents the development of LL-37-induced rosacea in mice. Vehicle- (0.2% DMSO in PBS, Vehicle/LL-37) or osthole- (Osthole/LL-37) treated Balb/c mice were injected with LL-37 into the dorsal skin (arrows) twice daily for 2 consecutive days. Mice that only received PBS on the dorsal skin were used as control. (A) Representative pictures of the dorsal skin (top panels) and H&E stained skin sections (bottom panels) of mice from different cohorts are shown. Scale bar = 100 μm. (B) Graphs represent inflammation scores and epidermal thickness of the H&E stained skin sections. (C) mRNA expression of selected gene targets from the excised skin was analyzed by real-time PCR. Values are plotted as fold change (2^{– ΔΔCt}) normalized to GAPDH levels. (D) The paraffin embedded skin sections from different cohorts of mice were stained with toludine blue to detect mast cells. Representiative pictures of the skin sections are shown. Bold arrows indicate intact mast cells whereas dotted arrows represent degranulated mast cells. The inset figure is an enlarged image of the mast cell(s) shown in the pictures. Scale bar = 100 μm. (E) Graph shows the percentage of degranulated mast cells in the skin tissue of different cohorts of mice. Data are mean ± SE. from n = 4–15 mice/group. Statistical significance was determined by unpaired Student’s t-test comparing the vehicle vs. osthole treated groups *p < 0.05 and **p < 0.01.