Prevention of oxidative DNA damage in inner organs and lymphocytes of rats by green tea extract
| Autor: | Michael Kundi, Franziska Ferk, Nina Kager, Miroslav Mišík, Karl-Heinz Wagner, Siegfried Knasmüller |
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| Rok vydání: | 2009 |
| Předmět: |
Antioxidant
DNA damage Colon medicine.medical_treatment Medicine (miscellaneous) Endogeny Green tea extract Biology Antioxidants Beverages chemistry.chemical_compound Interferon-gamma Random Allocation Blood plasma medicine Animals Humans Lymphocytes Nutrition and Dietetics Dose-Response Relationship Drug Tea Plant Extracts Tumor Necrosis Factor-alpha Molecular biology In vitro Rats chemistry Hepatocytes Animal studies Comet Assay Oxidation-Reduction DNA DNA Damage |
| Zdroj: | European journal of nutrition. 49(4) |
| ISSN: | 1436-6215 |
| Popis: | Consumption of green tea (GT) is associated with decreased incidences of specific forms of cancer in humans and it was postulated that its antioxidant (AO) properties may account for these effects. The evidence for AO effects of GT is mainly based on the results from in vitro experiments and on animal studies in which protection against chemically induced damage was monitored.The goal of the study was the investigation of the prevention of strand breaks and DNA migration attributable to endogenous oxidation of bases by GT extract (GTE) in inner organs and lymphocytes of untreated rats. In addition, immunological parameters and biochemical markers were monitored.DNA migration was measured in hepatocytes, colonocytes and lymphocytes after consumption of a low (1.3 mg/kg bw per day, 5 days) and a high dose (6.5 mg/kg bw per day, 5 days) of GTE in COMET assays (n = 5 animals per group). In addition, immunological parameters (TNF-alpha, IFN-gamma, IL-4 and IL-10), the total AO capacity and oxidized low-density lipoproteins were determined in plasma.No evidence for reduction in DNA damage was found with a lower dose, whereas with the higher dose, reduction in DNA migration attributable to formamidopyrimidine-DNA-glycosylase sensitive lesions (oxidized purines) and endonuclease III-sensitive sites (oxidized pyrimidines) (58 and 73%) was observed in lymphocytes; also, in colonocytes (reduction in FPG-sensitive sites by 46%) and hepatocytes (decrease in Endo III-sensitive sites by 74%) protective effects were found, while none of the other parameters was altered.Our results show that a dose of GTE, which is equivalent to consumption of 500 ml GT/p/day in humans protects lymphocytes and to a lesser extent inner organs against oxidative DNA damage, while no effect was seen with a lower dose corresponding to an uptake of 100 ml/p/day. |
| Databáze: | OpenAIRE |
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