title: Inhibition of NADPH oxidase subunits translocation by tea catechin EGCG in mast cell.
abstract: The inhibitory mechanism of tea catechins for allergy remains undefined. We studied the effect of catechins, mainly EGCG, on the activation of mast cell line canine cutaneous mastocytoma cells (CM-MC). Compound 48/80 induced the degranulation in CM-MC dose dependently, whereas its release of beta-hexosaminidase was inhibited by EGCG and O-methylated EGCG (EGCG-Me). Both catechins were found to inhibit intracellular ROS generation dose dependently together with DPI. Intracellular ROS generation in human polymorphonuclear leukocytes was also inhibited by EGCG. Neither L-NAME, ebeselen nor NAC inhibited ROS generation. From the Western blot analysis of the subunits components of NADPH oxidase, we detected cytosolic subunits; p47(phox), p67(phox), p40(phox), rac2 and membrane subunits; gp91(phox), p22(phox) in CM-MC. Cytosolic subunits were translocated from cytosol to membrane time dependently after stimulation with compound 48/80. EGCG and DPI inhibited cytosolic subunits from translocating into membrane. These data suggest that EGCG inhibits the activation of NADPH oxidase in CM-MC.
authors: Department of Food Science and Technology, Graduate School of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan.
authors: Hirofumi
authors: H
authors: Nishikawa
authors: Keiji
authors: K
authors: Wakano
authors: Seiichi
authors: S
authors: Kitani
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008407:Mast Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism*; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009861:Onium Compounds / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013662:Tea / Q000737:chemistry*; D013997:Time Factors; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
chemical_list: D009861:Onium Compounds; D010750:Phosphoproteins; D011480:Protease Inhibitors; D021122:Protein Subunits; D017382:Reactive Oxygen Species; D013662:Tea; C085072:neutrophil cytosol factor 40K; C079789:neutrophil cytosol factor 67K; D003189:p-Methoxy-N-methylphenethylamine; C007517:diphenyleneiodonium; D002392:Catechin; C045651:epigallocatechin gallate; D019255:NADPH Oxidases; D001619:beta-N-Acetylhexosaminidases