Epigallocatechin gallate and gallocatechin gallate in green tea catechins inhibit extracellular release of Vero toxin from enterohemorrhagic Escherichia coli O157:H7

• Published in: Biochimica et biophysica acta Vol. 1472; no. 1; pp. 42 - 50
• Main Authors: Sugita-Konishi, Yoshiko, Hara-Kudo, Yukiko, Amano, Fumio, Okubo, Tsutomu, Aoi, Nobuyuki, Iwaki, Masaaki, Kumagai, Susumu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 18.10.1999
• Subjects: Bacterial Proteins - metabolism; Bacterial Toxins - antagonists & inhibitors; Bacterial Toxins - metabolism; Catechin - analogs & derivatives; Catechin - chemistry; Catechin - pharmacology; Cell Extracts; Epigallocatechin gallate; Escherichia coli O157 - drug effects; Escherichia coli O157 - growth & development; Escherichia coli O157 - metabolism; Escherichia coli O157:H7; Extracellular release; Flavonoids - pharmacology; Gallocatechin gallate; Green tea catechin; Periplasm - metabolism; Shiga Toxin 1; Tea - chemistry; Vero toxins; Extracellular release; Vero toxins; Epigallocatechin gallate; Gallocatechin gallate; Escherichia coli O157:H7; Green tea catechin
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/S0304-4165(99)00102-6

We studied the effects of six catechin derivatives (catechin, epigallocatechin, epicatechin, epicatechin gallate, epigallocatechin gallate (EGCg) and gallocatechin gallate (GCg)) in green tea on the production and extracellular release of Vero toxins (VTs) from enterohemorrhagic Escherichia coli (EHEC) cultured at 37°C for 24 h. EGCg and GCg in the culture medium markedly inhibited extracellular VTs release from EHEC cells into the culture supernatant fluid at concentrations of 0.05 mg/ml or higher, as estimated by both the reversed passive latex agglutination assay and cytotoxic assay using Vero cells. Production and extracellular release of maltose binding protein, a periplasmic protein, into the culture supernatant were also inhibited by EGCg and GCg, indicating that their inhibitory effect on release from periplasm into the outer milieu is not specific to VTs, but general to the proteins accumulated in EHEC periplasm.