Inhibitory effect of Moutan Cortex aqueous fraction on mast cell-mediated allergic inflammation

Moutan Cortex and its major compounds have been shown to possess various biological activities, including anti-inflammatory properties. However, the effects of Moutan Cortex aqueous fraction (MCA) and its molecular mechanisms have yet to be elucidated. In this study, we attempted to evaluate the effects of MCA on mast cell-mediated allergy inflammation in vitro and in vivo compared with major Moutan Cortex compounds. Thus, we examined the anti-inflammatory effects of a water extract of Moutan Cortex by comparing the inhibition of β-hexosaminadase and tumor necrosis factor-α (TNF-α) release in an aqueous fraction with other major compounds of Moutan Cortex. The inhibitory mechanism of MCA was investigated by western blotting in IgE-mediated DNP-BSA-stimulated RBL-2H3 cells. We confirmed the pharmacological effects of MCA on compound 48/80-induced allergic reactions in a mouse model by assessing scratching behavior and passive cutaneous anaphylaxis (PCA)-like reaction. Consequently, MCA inhibited IgE-mediated DNP-BSA-induced β-hexosaminadase and TNF-α release via inactivation of p38, ERK, Akt, and NF-κB in RBL-2H3 cells. MCA reduced compound 48/80-induced PCA reaction and scratching behavior in mice. This inhibitory effect of MCA is more potent than major compounds of Moutan Cortex. In conclusion, our results suggest that MCA has more potential in the treatment of allergic inflammatory diseases compared to other major compounds of Moutan Cortex.