Antiallergic Herbal Composition from Scutellaria baicalensis and Phyllostachys edulis

We aimed to find antiallergic agents from natural sources using mast cells activated during allergic reaction. We screened over 2000 plants for blockade of histamine release and identified two of them, S. baicalenesis and P. edulis. Bioassay-guided fractionation led to two main constituent flavonoids, baicalin from S. baicalenesis roots and isoorientin from P. edulis leaves. Based on these two compounds, two standardized extracts (SSBE and SPEE) and a combined standardized herb composition (SHC) were developed. SSBE, SPEE, and SHC remarkably inhibited histamine and leukotriene release from mast cells activated by anti-OVA/OVA binding, and SHC showed a stronger inhibition than either extract alone. SHC also showed greater inhibition potency than either aspirin or cromolyn, which are known antiallergic agents. Our results suggest that SHC reduce degranulation during mast cell activation and could be a promising candidate for the treatment of immune/allergic diseases related to mast cells.