DNCB-Induced Atopic Dermatitis Model

Male BALB/c mice (7-week-old) were purchased from Orient Bio Inc. (Seongnam, Korea). The mice were divided into four groups: Group I, naive; Group II, DNCB + vehicle (phosphate-buffered saline (PBS)); Group III, DNCB + 0.5% SSA; Group Ⅳ, DNCB + 0.3% SSC. The mouse in vivo study was performed as described previously, with minor modifications [26 (link)]. Briefly, all mice except for Group I were sensitized with 4% SDS on the back skin to disrupt the skin barrier; after 4 h, the SDS-sensitized areas were treated with 1% DNCB dissolved in acetone:olive oil mixture (1:3, v/v). The mice were treated with DNCB once daily for 3 days on the SDS-sensitized area and then rested for 4 days. SSA and SSC were dissolved in 70% ethanol at a concentration of 0.5% and 0.3%, respectively. After a challenge with 0.5% DNCB, 120 µL of 0.5% SSA or 0.3% SSC was dropped (Group II and Group IV). After sacrificing all mice on day 22, paraffin-embedded tissue sections were prepared. All animal experiments were performed according to the protocols approved by the Konkuk University Institutional Animal Care and Use Committee (approval number KU19129).