Tadakatsu Shimamura

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Catechin (epicatechin (EC), epicatechin gallate (ECg), epigallocatechin (EGC) and epigallocatechin gallate (EGCg)), which occur in green tea and black tea, possess strong bactericidal action. We observed a reactive oxygen species that was generated from the catechins as the active mechanism: and this reactive oxygen was identified. EGCg reacted with the(More)
Combinations of carbapenems and epigallocatechin gallate (EGCg; a main constituent of tea catechins) showed potent synergy against 24 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). MICs of imipenem in the presence of EGCg at 3.125, 6.25, 12.5, and 25 microg/ml, were restored to the susceptible breakpoint (< or =4 microg/ml) for 8,(More)
Since green tea catechins are known to have antimicrobial activity against a variety of microorganisms, their possible effects on Helicobacter pylori in combination with antibiotics were examined. Fifty-six clinical isolates of H. pylori, including 19 isolates highly resistant to metronidazole (MTZ) and/or clarithromycin (CLR), were used to determine in(More)
We examined the antibacterial effects of epigallocatechin gallate (EGCg, the main constituent of tea catechins) against various strains of Staphylococcus and Gram-negative rods. Compared to the minimum inhibitory concentrations (MICs) of EGCg against S. aureus, S. epidermidis, S. hominis, and S. haemolyticus (50-100 micro g/ml), higher MICs (>or=800 micro(More)
Epigallocatechin gallate (EGCg), the major tea catechin, is known as a potent anti-bacterial agent. In addition, anti-tumor promoting, anti-inflammatory, anti-oxidative and antiviral activities have been reported. In the present study, we investigated possible anti-human immunodeficiency virus type-1 (HIV-1) activity of EGCg and its mechanisms of action in(More)
The combination of epigallocatechin gallate (EGCg, a main constituent of tea catechins) with penicillin showed synergism against 21 clinical isolates of penicillinase-producing Staphylococcus aureus. Besides binding directly to peptidoglycan, the inhibition of penicillinase activity by EGCg is responsible for the synergism. EGCg inhibited the penicillinase(More)
Mast cells are potent effectors playing a key role in IgE-associated hypersensitivity reactions, allergic disorders, inflammation and protective immune responses. Mast cell development in vivo occurs mainly in non-hematopoietic microenvironments and increased mast cell numbers can be seen in various inflammatory diseases and pathologic conditions. SCF (also(More)
Additive, indifferent and antagonistic effects were observed in combinations of epigallocatechin gallate (EGCg, a main constituent of tea catechins) with12 non-beta-lactam antibiotics against methicillin-resistant Staphylococcus aureus (MRSA). The combinations of EGCg with the inhibitors of either protein or nucleic acid synthesis showed additive or(More)
Lowe Center for Thoracic Oncology, Department of Medical Oncology, Belfer Institute for Applied Cancer Science, Department of Cancer Biology, Department of Biological Chemistry and Molecular Pharmacology Dana Farber Cancer Institute, Boston, MA;Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA; Pfizer Global(More)
Epigallocatechin gallate (EGCg), the major tea catechin, is known as a potent anti-microbial and anti-tumor compound. The effects of EGCg on host defense mechanisms against Listeria monocytogenes infection were examined in vitro using mouse peritoneal exudate cells. The study showed that EGCg inhibited the intracellular growth of L. monocytogenes in(More)