Anti-inflammatory and anti-pruritic effects of Chi-Huang Solution in a murine model of allergic contact dermatitis

In treating atopic dermatitis, multi-mode management is adopted, including trying to avoid the allergens, controlling and preventing secondary infections, and using drugs to control itching. At present, most of the commonly used anti-pruritic drugs in the clinic are single-target and lead to serious side effects. Many studies have shown that a variety of traditional Chinese medicines have significant anti-inflammatory and anti-pruritic effects, and have the characteristics of multiple components, multiple targets, and multiple effects. The study aimed to explore the anti-inflammatory and anti-pruritic effects of the Chi-Huang Solution in a murine model of Allergic contact dermatitis (ACD). This study considers the effectiveness of the Chi-Huang Solution for external use on skin to provide an experimental basis for the clinical development and application of Chinese medicine and related preparations for Canine atopic dermatitis (CAD). Forty-two male SPF C57BL/6 mice were randomly divided into control group (n = 6), ACD model group (n = 6), HAC control group (n = 6), and 4 Chi-Huang Solution groups (n = 6 in each group). With SADBE induce the murine model of ACD chronic pruritus, and initially evaluate whether the model is successful by counting scratching behavior, measuring the skin fold thickness and skin lesion score within 1 h. After treating the ACD model mice with deionized water, HAC, 1CH, 2CH, 3CH, and 4CH for 7 days, behavioral changes were used to evaluate the anti-pruritic effect. The skin fold thickness, skin lesion score, and spleen index were used to evaluate the anti-inflammatory effect of the Chi-Huang Solution. H.E. staining was used for the epidermal thickness measurement and pathological evaluation. RT-qPCR was used to analyze the mRNA expression of related inflammatory factors such as IL-1β, TNF-α, IL-33, IL-4, IL-17A, CXCL10, and its receptor CXCR3 in the skin of the lesion site, as well as to detect the mRNA expression of pruritus-related genes such as TRPV1, TRPA1, and GRP in DRG. After the treatment of low-dose (0.1 g/mL) and medium-dose (0.2 g/mL) Chi-Huang Solution, the scratching times both decreased significantly (P