Inhibition of NADPH oxidase subunits translocation by tea catechin EGCG in mast cell.
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.
Nishikawa
Hirofumi
H
Department of Food Science and Technology, Graduate School of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477, Japan.
Wakano
Keiji
K
Kitani
Seiichi
S
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
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