Comparative Efficacy of Coral Calcium Carried Hydrogen versus Dexamethasone in a Mouse Model of Allergic Contact Dermatitis

Introduction: Allergic contact dermatitis (ACD) is a common T cell-mediated delayed hypersensitivity reaction characterized by chronic skin inflammation. Coral calcium carried hydrogen (CCH), a novel solid-phase hydrogen carrier, enables sustained hydrogen release and demonstrates superior stability compared to conventional hydrogen delivery methods. However, its therapeutic potential in ACD remains unexplored. Methods: ACD was induced in female BALB/c mice (8-week-old) using 2,4-dinitrochlorobenzene (DNCB). Mice were divided into four groups: Control, DNCB model, CCH-treated (oral CCH), and dexamethasone (DEX)-treated (oral DEX). Disease severity was assessed through dermatitis scores, scratching frequency, spleen coefficient, and histopathological analysis. Serum cytokine levels and peripheral blood immune cell profiles were evaluated to elucidate the underlying mechanisms. Results: CCH treatment significantly ameliorated ACD symptoms, comparable to DEX, as evidenced by reduced dermatitis scores, scratching behavior, and spleen enlargement. Histologically, CCH promoted ulcer healing and more effectively suppressed epidermal hyperplasia and skin inflammation than DEX. Mechanistically, CCH selectively reduced serum IgE and IL-17 levels while decreasing lymphocyte counts and proportions. In contrast, DEX primarily inhibited monocytes and neutrophils. Conclusion: CCH exerts its therapeutic effects by modulating lymphocyte-mediated immune responses and suppressing pro-inflammatory cytokines, offering a promising therapeutic alternative with efficacy comparable to glucocorticoids.