Colla Corii Asini suppresses the atopic dermatitis-like skin lesions in NC/Nga mice and HaCaT keratinocytes

Abstract

In traditional medicine, Colla Corii Anisi (donkey hide gelatin; CA) has been used to treat various diseases, such as anemia and gynecologic diseases, as well as strengthen blood and vital fluids. Despite the varied therapeutic efficacy and pharmacological effects of CA, its effects against atopic dermatitis (AD) have not yet been reported. We hypothesized that gelatin-rich CA alleviates AD-skin-like symptoms, preventing AD development and skin inflammation. We aimed to investigate the effect of CA on AD-like skin lesions and to determine the effective application of CA depending on different administration routes.The effects of CA and associated molecular mechanisms were evaluated in Dermatophagoides farinae body (Dfb)-induced AD mice and tumor necrosis factor-α/interferon-γ-stimulated HaCaT keratinocytes using histological analysis, transepidermal water loss (TEWL) measurements, enzyme-linked immunosorbent assay, western blot analysis, and quantitative reverse transcription-polymerase chain reaction. Oral administration, topical application, and combination treatment with CA improved the severity scores of AD-like skin lesions and reduced TEWL, serum immunoglobulin E, and inflammatory cytokines in Dfb-induced AD mice. Treatment with CA also decreased epidermal thickness and mast cell infiltration through the inhibition of AD-related cytokines. CA suppressed mitogen-activated protein kinases (MAPK)/ signal transducer and activator of transcription (STAT) activation in Dfb-induced AD mice and HaCaT keratinocytes. Collectively, these findings suggest that CA has a therapeutic potential against AD by suppressing inflammatory mediators and downregulating the MAPK/STAT pathway.