DNCB-induced AD-like skin lesions in mice

The dorsal skin of BALB/c mice was sensitized with DNCB (Sigma-Aldrich, St. Louis, MO, USA) to induce AD-like symptoms as previously described.²⁰ Briefly, following dorsal hair removal (approximately 4 cm²), 150 μL of 2% DNCB solution (dissolved in a 3:1 mixture of acetone and olive oil) was applied to the dorsal skin. Four days later, 150 μL of 0.5% DNCB was applied to the dorsal skin every 3 days (Figure 1) throughout the experiment to induce AD-like symptoms.

Schematic illustration of allergic contact dermatitis (ACD) induction and phloretin treatment. The dorsal skin regions of the BALB/c mice (n = 5) from which the hair was removed were sensitized with 2% DNCB on day 1, followed by a series of repetitive challenges with 0.5% DNCB every third day thereafter. In addition, 50 and 100 mg/kg of phloretin were orally administered to the BALB/c mice daily from day 7 to day 28 before the mice were sacrificed 4 h after the last DNCB challenge. The pathological conditions caused by DNCB irritation with or without phloretin treatment were examined.