Loureirin B is a flavonoid originally isolated from D. cochinchinensis, a major component of the traditional herbal medicine dragon's blood, and has diverse biological activities.^1,2,3 It inhibits Kv1.3-mediated currents, induces membrane depolarization, and reduces calcium influx in Jurkat T cells.¹ It also inhibits phytohemagglutinin-induced IL-2 release from these cells. Loureirin B (25 μg/ml) reduces type I collagen and fibronectin protein levels in TGF-β1-stimulated fibroblasts as well as contraction of TGF-β1-stimulated fibroblasts in a gel contraction assay.² It reduces type I collagen and fibronectin protein levels and inhibits phosphorylation of ERK and JNK in isolated human hypertrophic scar tissue. Loureirin B increases glucose absorption and intracellular ATP levels in Ins-1 cells via inhibition of the KATP current and intracellular influx of calcium.³