| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
* National Institute of Vegetable and Tea Science, National Agriculture Research Organization, and
School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan;
Department of Pharmacology, Gifu Pharmaceutical University, Gifu, Japan;
Kitakyushu National College of Technology, and
¶ Division of Bioresources and Bioenvironmental Science, Kyushu University, Fukuoka, Japan; and
|| Division of Cell Biology, La Jolla Institute for Allergy and Immunology, San Diego, CA 92121
Tea contains a variety of bioactive compounds. In this study, we show that two O-methylated catechins, (-)-epigallocatechin-3-O-(3-O-methyl) gallate and (-)-epigallocatechin-3-O-(4-O-methyl) gallate, inhibit in vivo mast cell-dependent allergic reactions more potently than their nonmethylated form, (-)-epigallocatechin-3-O-gallate. Consistent with this, these O-methylated catechins inhibit IgE/Ag-induced activation of mouse mast cells: histamine release, leukotriene release, and cytokine production and secretion were all inhibited. As a molecular basis for the catechin-mediated inhibition of mast cell activation, Lyn, Syk, and Bruton’s tyrosine kinase, the protein tyrosine kinases, known to be critical for early activation events, are shown to be inhibited by the O-methylated catechins. In vitro kinase assays using purified proteins show that the O-methylated catechins can directly inhibit the above protein tyrosine kinases. These catechins inhibit IgE/Ag-induced calcium response as well as the activation of downstream serine/threonine kinases such as Akt and c-Jun N-terminal kinase. These observations for the first time have revealed the molecular mechanisms of antiallergic effects of tea-derived catechins.
This article has been cited by other articles:
|
|
 |
|
  I. Ishida, C. Kohda, Y. Yanagawa, H. Miyaoka, and T. Shimamura Epigallocatechin gallate suppresses expression of receptor activator of NF-{kappa}B ligand (RANKL) in Staphylococcus aureus infection in osteoblast-like NRG cells J. Med. Microbiol., August 1, 2007; 56(8): 1042 - 1046. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Nishimoto, S.-W. Lee, H. Hong, K. G. Potter, M. Maeda-Yamamoto, T. Kinoshita, Y. Kawakami, R. S. Mittler, B. S. Kwon, C. F. Ware, et al. Costimulation of mast cells by 4-1BB, a member of the tumor necrosis factor receptor superfamily, with the high-affinity IgE receptor Blood, December 15, 2005; 106(13): 4241 - 4248. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
