['Human mast cells are multifunctional cells capable of a wide variety of inflammatory responses. Baicalein (BAI), isolated from the traditional Chinese herbal medicine Huangqin (Scutellaria baicalensis Georgi), has been shown to have anti-inflammatory effects. We examined its effects and mechanisms on the expression of inflammatory cytokines in an IL-1beta- and TNF-alpha-activated human mast cell line, HMC-1.', 'HMC-1 cells were stimulated either with IL-1beta (10 ng/ml) or TNF-alpha (100 U/ml) in the presence or absence of BAI. We assessed the expression of IL-6, IL-8, and MCP-1 by ELISA and RT-PCR, NF-kappaB activation by electrophoretic mobility shift assay (EMSA), and IkappaBalpha activation by Western blot.', 'BAI (1.8 to 30 muM) significantly inhibited production of IL-6, IL-8, and MCP-1 in a dose-dependent manner in IL-1beta-activated HMC-1. BAI (30 muM) also significantly inhibited production of IL-6, IL-8, and MCP-1 in TNF-alpha-activated HMC-1. Inhibitory effects appear to involve the NF-kappaB pathway. BAI inhibited NF-kappaB activation in IL-1beta- and TNF-alpha-activated HMC-1. Furthermore, BAI increased cytoplasmic IkappaBalpha proteins in IL-1beta- and TNF-alpha-activated HMC-1.'] Does baicalein inhibit IL-1beta- and TNF-alpha-induced inflammatory cytokine production from human mast cells via regulation of the NF-kappaB pathway?