Protective effects of aqueous extracts of Rhizopus oryzae on atopic dermatitis in NC/Nga mice

Abstract

The aqueous extract of Rhizopus oryzae U-1 (RU) increases the number of Th1 cells, which defend against Salmonella infection and regulate immunity in rats. In this study, we demonstrated the anti-dermatitis effects of RU in a picryl chloride (PiCl)-induced mouse model of atopic dermatitis. RU treatment significantly decreased the time-dependent exacerbation of dermatitis scores and increased the final body weight and food intake. A significant decrease in serum IgE and IL-4 levels confirmed that RU treatment suppressed the exacerbation of atopic dermatitis. Flow cytometric analysis revealed that RU treatment significantly increased CD4⁺ IFN-γ⁺ (Th1) and decreased CD4⁺ IL-4⁺ (IL-4⁺ Th) cell numbers. Thus, the oral administration of RU effectively suppressed atopic dermatitis induced by PiCl, and the decrease in the number of CD4⁺ IL-4⁺ cells and serum IL-4 levels may be partially mediated by RU in mice.