Inhibitory Effects of Donkey Hide Gelatin on DNCB-Induced Atopic Dermatitis in NC/Nga Mice

The increase of atopic dermatitis has led to higher socio-economic cost and raised a need for alternative medicine as novel therapeutic agents. In this study, we aimed to evaluate the inhibitory effects of Donkey Hide Gelatin (DHG) water extract on DNCB-induced atopic dermatitis in NC/Nga mice and on tumor necrosis factor (TNF)-alpha/interferon (IFN)-gamma-treated keratinocytes and to investigate its underlying molecular mechanisms. NC/Nga mice were induced by DNCB, administered Dexamethasone (3 mg/kg) or DHG water extracts (100-400 mg/kg) for 3 weeks. The skin symptom score, serum IgE and immune cells were measured, the ALN, spleen and dorsal skin tissue were extracted for FACS, quantitative real-time PCR and histology analysis. In vitro, HaCaT cells were induced by TNF-alpha/IFN-gamma, the levels of pro-inflammatory cytokines and chemokines and its underlying mechanism were measured by ELISA and Western blot. As a result, DHG groups showed a significant decrease in the skin symptom score and the immune cell absolute number. It also showed a marked reduction of allergic and the levels of neutrophils and eosinophils in histology analysis. In TNF-alpha/IFN-gamma induced HaCaT cells, DHG showed inhibition effects on IL-6, IL-8, TARC and RANTES, it also downregulated the expression of ICAM-1 and COX-2, up-regulated the expression of Filaggrin. Furthermore, DHG suppressed the activation of NF-kappa B and mitogen-activated protein kinases (MAPK) signaling pathway induced by TNF-alpha/IFN-gamma. Taken together, DHG maybe a potential therapeutic agent or supplement for skin inflammatory disease such as atopic dermatitis.

Automated summary

The increase of atopic dermatitis has led to higher socio-economic cost and raised a need for alternative medicine. This study evaluated the inhibitory effects of Donkey Hide Gelatin (DHG) water extract on atopic dermatitis and investigated its underlying mechanisms. The results showed that DHG reduced skin symptoms, immune cell numbers, allergic reactions, and levels of neutrophils and eosinophils. In addition, DHG inhibited pro-inflammatory cytokines and chemokines in keratinocytes, and suppressed NF-kappa B and MAPK signaling pathway activation. DHG may be a potential therapeutic agent or supplement for atopic dermatitis.