PT - JOURNAL ARTICLE AU - Byung Hak Kim AU - Eunmiri Roh AU - Hwa Young Lee AU - In-Jeong Lee AU - Byeongwoo Ahn AU - Sang-Hun Jung AU - Heesoon Lee AU - Sang-Bae Han AU - Youngsoo Kim TI - Benzoxathiole Derivative Blocks Lipopolysaccharide-Induced Nuclear Factor-κB Activation and Nuclear Factor-κB-Regulated Gene Transcription through Inactivating Inhibitory κB Kinase β AID - 10.1124/mol.107.041251 DP - 2008 Apr 01 TA - Molecular Pharmacology PG - 1309--1318 VI - 73 IP - 4 4099 - http://molpharm.aspetjournals.org/content/73/4/1309.short 4100 - http://molpharm.aspetjournals.org/content/73/4/1309.full SO - Mol Pharmacol2008 Apr 01; 73 AB - Benzoxathiole derivatives have been used in the treatment of acne and have shown cytostatic, antipsoriatic, and antibacterial properties. However, little is known about the molecular basis for these pharmacological properties, although nuclear factor (NF)-κB activation is closely linked to inflammation and cell proliferation. Here, we demonstrate that the novel small-molecule benzoxathiole 6,6-dimethyl-2-(phenylimino)-6,7-dihydro-5H-benzo-[1,3]oxathiol-4-one (BOT-64) inhibits NF-κB activation with an IC50 value of 1 μM by blocking inhibitory κB(IκB) kinase β (IKKβ), and suppresses NF-κB-regulated expression of inflammatory genes in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. BOT-64 inhibits IKKβ-mediated IκBα phosphorylation in LPS-activated macrophages, resulting in sequential prevention of downstream events, including proteolytic degradation of IκBα, DNA binding ability, and transcriptional activity of NF-κB. BOT-64 inhibits LPS-inducible IKKβ activity in the cells and catalytic activity of highly purified IKKβ. Moreover, the effect of BOT-64 on cell-free IKKβ was abolished by substitution of Ser-177 and Ser-181 residues in the activation loop of IKKβ to glutamic acid residues, indicating a direct interaction site of benzoxathiole. BOT-64 attenuates NF-κB-regulated expression of inflammatory genes such as inducible nitric-oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in LPS-activated or expression vector IKKβ-transfected macrophages. Furthermore, BOT-64 dose-dependently increases the survival rates of endotoxin LPS-shocked mice. The American Society for Pharmacology and Experimental Therapeutics