Abstract
Chaenomeles sinensis Koehne (CS) has been used in a traditional oriental medicine for treating throat diseases, anaphylaxis, viral infection, and inflammation. This study investigated the underlying mechanism of anti-allergic effect of CS. Leaves of CS plants were dried, powdered, and then underwent extraction with DMSO. Both ELISA and western blotting were performed to evaluate cytokine concentration and the expression and activation of filaggrin and JNK. Five-week-old female NC/Nga mice were used as an AD-like mouse model by treating them with 2,4-dinitrochlorobenzene (DNCB). The secretion of TARC, MCP-1, and IL-8 is increased by TNF-α and IFN-γ in HaCaT cells, and CS extract inhibited the increased production of TARC, MCP-1, and IL-8. TNF-α and IFN-γ suppressed filaggrin expression by activating JNK. CS extract recovered the expression of filaggrin decreased by TNF-α and IFN-γ by blocking the activation of JNK. In vivo experiment, CS administration reduced thickening of the epidermis and infiltration of inflammatory cells into the dermis as compared to DNCB treatment. Moreover, the decrease of filaggrin expression due to DNCB treatment was recovered by CS administration. The serum IgE level was decreased by CS treatment. The levels of IL-4, IL-5, IL-13 and eotaxin in mouse splenocytes increased after treatment with concanavalin A, and the secretions of IL-4, IL-5, IL-13 and eotaxin were lower in the CS-treated group than in the DNCB group. These results may contribute to the development of a CS-based drug for the treatment of atopic dermatitis.