Inhibitory Effect of Rhododendron Mucronulatum Root Extract on Allergic Inflammation

Abstract

Objective: In this study, we investigated the protective effect of rhododendron mucronulatum extract (RME) on allergic reactions and inflammation.Methods: The effect of RME was determined using ELISA and RT-PCR in RBL-2H3 mast cells and RAW 264.7 macrophage cells. We determined cell viability, β-hexosaminidase release, and the synthesis of IL-4 and TNF-α in RBL-2H3 cells. In addition, we determined NO from RAW 264.7 and the gene expression of IL-1β, iNOS, IL-6, TNF-α, and IL-10.Results: RME inhibited β-hexosaminidase release and synthesis of IL-4 and TNF-α in RBL-2H3 by the anti-DNP IgE plus DNP-HSA stimulation. In addition, RME inhibited the production of NO and the gene expression of IL-1β, iNOS, IL-6, and TNF-α in LPS-stimulated RAW 264.7 cells.Conclusion: From these results, we concluded that RME possesses anti-allergic activity and anti-inflammatory activity due to the inhibition of mast cells and macrophage function.