Efficacy of Chi-Huang cream as an anti-inflammatory and anti-pruritic agent in treating chronic pruritus

Pruritus is the main clinical symptom of skin diseases in animals and humans. Treatment outcomes from current conventional medicine are often unsatisfactory, since the same pruritus mediator may play multiple roles in different pruritus-associated diseases. Chi-Huang formula is the experiential traditional Chinese medicine formula for canine atopic dermatitis (CAD), and Chi-Huang solution for topical use has been shown to exhibit significant anti-inflammatory and anti-pruritic effects. This study aims to assess the anti-inflammatory and antipruritic effects of Chi-Huang cream in a squaric acid dibutyl ester (SADBE)-induced allergic contact dermatitis (ACD) chronic pruritus murine model in vivo. Thirty C57BL/6 N mice were randomly divided into six groups to evaluate the therapeutic effects of Chi-Huang cream on SADBE-induced allergic contact dermatitis (ACD). Except for the control group, all mice underwent ACD induction and received different treatments for eight days. The high-dose Chi-Huang (CH-H) group showed significantly improved skin lesions, reduced scratching behavior, and decreased skin thickness compared to the saline group, with efficacy comparable to hydrocortisone butyrate (HBC). Histological analysis confirmed reduced epidermal thickness and mast cell counts in CH-H treated mice. Moreover, Chi-Huang cream treatment showed fewer adverse effects, with better spleen and thymus indices than the HBC group. In a conclusion, Chi-Huang cream exhibits significant anti-inflammatory and anti-pruritic effects under a SADBE-induced ACD condition, with minimal impact on spleen and thymus indices. These findings suggest Chi-Huang cream may serve as a promising therapeutic agent in treating chronic pruritus.