DNCB-Induced AD Model in NC/Nga Mice

AD-like skin lesions were induced by DNCB (Sigma-Aldrich, St Louis, MO, USA) topical application in NC/Nga mice described in the methods of our previous study [20 (link)]. Briefly, after 1 week of acclimation, dorsal hair of NC/Nga mice was removed by using an electric shaver. After shaving hair, the mice were randomly divided into the following 6 groups, and 8 mice were allocated in each group (sample size was n = 8 per group): nontreated control group (Normal, naïve control group), DNCB-treated group (Control, negative control group), DNCB-treated + prednisolone 3 mg/kg (Sigma-Aldrich, St Louis, MO, USA) group (PD, positive control group), and DNCB-treated + F.NONI 250, 500, 1000 mg/kg group (F.NONI 250, F.NONI 500, F.NONI 1000). To induce AD-like skin lesions, 1% DNCB was dissolved in an acetone and ethanol mixture (2:3 v/v) and then was topically applied on the shaved dorsal area (200 µL) and right ear (100 µL) twice a week for sensitization. Following the sensitization, 0.4% DNCB dissolved in an acetone and olive oil mixture (3:1 v/v) was challenged on the dorsal skin (150 µL) and right ear (50 µL) repeatedly three times a week for 9 weeks. The mice in the normal and control groups were orally administered 0.5% carboxymethyl cellulose (0.5% CMC). Administration of PD (3 mg/kg prednisolone) and F.NONI (250, 500, 1000 mg/kg) was performed daily for 4 weeks. AD-like skin lesions were decided by dermatitis score, scratching behavior, and histological and immunological parameters.