The Suppressive Effect of Mamiran Cream on Atopic Dermatitis-Like Skin Lesions In Vivo

Background. The Chinese herbal formula Mamiran cream (MMC) has been known for its ameliorative effects on diverse skin diseases, such as eczema. Atopic dermatitis (AD; eczema) is a chronic recurrent skin disease dominated by T-helper type 2-driven inflammation (Th2). Objective. In this study, the inhibitory effect of MMC on AD was investigated in vivo. Methods. An animal model was established by sensitization with 2,4-dinitrochlorobenzene (DNCB) on the skin of SD rats. Cutaneous administration of MMC was applied, and its mechanism of action was investigated via RT-PCR and IHC assay. Result. Our data showed that topical application of MMC reduced the skin severity scores and alleviated the histological changes. Furthermore, immunohistochemical analysis demonstrated that MMC significantly decreased the levels of Th2 cytokine IL-5 and IL-4Ra in the skin lesion. In addition, it was demonstrated that MMC downregulated the mRNA expression of TNF-α, IL-1β, IL-6, IL-10, and TLR4. Moreover, MMC inhibited the activation of NF-κB, JNK1, and STAT6 pathways in skin lesions. Conclusions. Our findings suggest that MMC exhibits the inhibitory effect on AD, suggesting that MMC may be a potential therapeutic agent for this atopic disorder.