Figure 1.
NC/Nga mice were divided into five groups: (1) naïve control (vehicle), (2) DNCB+vehicle, (3) DNCB+200 nmol 7,8,4′-THIF, (4) DNCB+400 nmol 7,8,4′-THIF, and (5) DNCB+tacrolimus. To induce AD-like symptoms, DNCB was topically applied on NC/Nga mice. A day after complete dorsal hair removal, 1% DNCB was applied (day −4). Five days after dorsal hair removal, 0.2% DNCB was challenged three times a week for three weeks (day 0–20). 7,8,4′-THIF or tacrolimus was topically applied seven times a week for 3 weeks (day 0–20).
Figure 2.
Effect of 7,8,4′-THIF on DNCB-induced AD-like symptoms in NC/Nga mice.
(A) Images of skin lesions from the groups of mice were taken on the last day of the experiment (day 21). (B) Dermatitis scores were evaluated weekly from day −5 to 21. (C) Ear thickness was measured from day −5 to 21. (D) H&E-stained ear skin on day 21 (100×). Arrows indicate epidermal hypertrophy. Data represent the mean ± SEM (n = 9). Means with letters (a–d) within a graph are significantly different from each other at p<0.05.
Figure 3.
Effect of 7,8,4′-THIF on DNCB-induced scratching incidence in NC/Nga mice.
Scratching time was evaluated on the last day of the experiment (day 21). Data represent the mean ± SEM (n = 9). Means with letters (a–b) within a graph are significantly different from each other at p<0.05.
Figure 4.
Effect of 7,8,4′-THIF on DNCB-induced eosinophil and mast cell infiltration in skin lesions of NC/Nga mice.
(A) Representative images depicting the histological features of skin collected on day 21 are shown. Congo red (CR) and toluidine blue (TB) staining were used to identify eosinophils and mast cells, respectively. The arrows indicate the CR-stained eosinophils and the TB-stained mast cells. Cells were counted under a microscope at 400× magnification. The numbers of (B) eosinophils and (C) mast cells in 1 µm2 of skin were calculated. Data represent the mean ± SEM (n = 9). Means with letters (a–b) within a graph are significantly different from each other at p<0.05.
Figure 5.
Effect of 7,8,4′-THIF on DNCB-induced increase in serum IgE level in NC/Nga mice.
Blood was collected on the last day of the experiment (day 21). The level of serum IgE was measured with ELISA. Data are the means ± SEM (n = 6). Means with letters (a–c) within a graph are significantly different from each other at p<0.05.
Figure 6.
Effect of 7,8,4′-THIF on DNCB-induced increase in TEWL in NC/Nga mice.
The level of TEWL in mouse dorsal skin was measured using a skin evaporative water recorder on the last day of the experiment (day 21). Data are the means ± SEM (n = 9). Means with letters (a–e) within a graph are significantly different from each other at p<0.05.
Table 1.
Effects of 7,8,4′-THIF on DNCB-induced increase in chemokine TARC and Th2 and Th1 cytokines in NC/Nga mice.