IL4 and atopic eczema: Papyriflavonol A, isolated from the root bark of B. papyrifera, exhibits strong antimicrobial activity against different pathogenic bacteria and fungi9, whereas a 70% ethanol leaf extract of B. kazinoki was reported to dramatically reduce ear and dorsal skin thickness and other clinical symptoms in mice with atopic dermatitis, possibly via the downregulation of immunoglobulin E (IgE) and interleukin-4 (IL-4) plasma levels5.