Effects of aqueous green tea extract on activities of DNA turn-over enzymes in cancerous and non-cancerous human gastric and colon tissues.
OBJECTIVE
The purpose of this study was to investigate possible effects of green tea extract on the activities of DNA turn-over enzymes, namely adenosine deaminase (ADA) and xanthine oxidase (XO) in gastric and colon tissues from patients with stomach and colon cancer.


METHODS
Six cancerous and 6 non-cancerous adjacent human gastric tissues, and 7 cancerous and 7 non-cancerous adjacent colon tissues obtained surgically were treated with aqueous green tea extract at 3 different concentrations for 1 hour, and then ADA and XO activities were measured.


RESULTS
In all of the tissues, XO activities were found to elevate after treatment with green tea extract. Additionally, ADA activity was found to be inhibited in the cancerous gastric tissues by the green tea extract. Elevated XO and reduced ADA activities due to treatment with green tea extract may lower salvage pathway activity and lead to inhibition in carcinogenesis.


CONCLUSIONS
Our data suggest that green tea may support the medical treatment of stomach and colon cancer.
Ankara University Faculty of Medicine, Department of Biochemistry, Ankara, Turkey.
Imge B
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Ergüder
Mehmet
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Namuslu
Ulaş
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Sözener
Erdinç
E
Devrím
Aslihan
A
Avci
Hilmi
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Kocaoğlu
Ilker
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Durak
Erdal
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Gocmen
D000243:Adenosine Deaminase / Q000187:drug effects*; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D028241:Camellia sinensis; D003110:Colonic Neoplasms / Q000201:enzymology*; D004273:DNA, Neoplasm / Q000187:drug effects*; D006801:Humans; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D013274:Stomach Neoplasms / Q000201:enzymology*; D014969:Xanthine Oxidase / Q000187:drug effects*
D000975:Antioxidants; D004273:DNA, Neoplasm; D010936:Plant Extracts; C465546:green tea extract AR25; D014969:Xanthine Oxidase; D000243:Adenosine Deaminase