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Catechins are not major components responsible for anti-genotoxic effects of tea extracts against nitroarenes.
Mutat Res. 2001 Sep 20; 496(1-2):75-81.MR

Abstract

The anti-genotoxic properties of tea leaf extracts were examined in a Salmonella umu-test. Seven non-fermented teas (green tea), one semi-fermented tea (oolong tea), two fermented teas (black tea and Chinese pu er tea) and two other teas were examined for their anti-genotoxic abilities and for their catechins contents. This was to study the relationship between catechins contents and anti-genotoxic activity of various tea leaf extracts. All types of tea extracts showed more potent suppressive effects against umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK 1002 induced by four nitroarenes (1-nitropyrene, 2-nitrofluorene, 3-nitrofluoranthene and a mixture of 1,6- and 1,8-dinitropyrene) rather than 4-NQO, AF-2 and MNNG. The anti-genotoxic effect of 12 tea leaf extracts on 1-NP, 2-NF, 3-NF and DNP decreased in the order: oolong tea (semi-fermented tea)>black tea (fermented tea)>sencha (non-fermented tea, an ordinary grade green tea)>tocyucya (other tea)>Chinese pu er tea (fermented tea). The amount of catechins (EGC, C, EGCG, EC and ECG) in various teas in decreasing order was non-fermented tea>semi-fermented tea>fermented tea>other tea. A remarkable feature was the effectiveness of black tea and Chinese pu er tea in suppressing the genotoxicity induced by nitroarenes, in spite of the fact that these fermented teas do not have high catechins contents. Statistical analysis showed that no significant (P<0.01) correlation was found between the anti-genotoxicity of tea extracts against nitroarenes and the catechins contents in tea leaf extracts. In further experiment, fractionation of sencha extract by HPLC revealed that anti-genotoxicity of the peak fraction corresponding to catechins accounted for <10% of the total anti-genotoxic activity of sencha extract against for 1-nitropyrene. These results suggest that catechins are not major components responsible for the anti-genotoxic effects of tea leaf extracts against direct-acting nitroarenes.

Authors+Show Affiliations

Department of Food and Nutrition Science, Kyoto Women's University, 605-8501, Kyoto, Japan. ooe@kyoto-wu.ac.jpNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

11551482

Citation

Ohe, T, et al. "Catechins Are Not Major Components Responsible for Anti-genotoxic Effects of Tea Extracts Against Nitroarenes." Mutation Research, vol. 496, no. 1-2, 2001, pp. 75-81.
Ohe T, Marutani K, Nakase S. Catechins are not major components responsible for anti-genotoxic effects of tea extracts against nitroarenes. Mutat Res. 2001;496(1-2):75-81.
Ohe, T., Marutani, K., & Nakase, S. (2001). Catechins are not major components responsible for anti-genotoxic effects of tea extracts against nitroarenes. Mutation Research, 496(1-2), 75-81.
Ohe T, Marutani K, Nakase S. Catechins Are Not Major Components Responsible for Anti-genotoxic Effects of Tea Extracts Against Nitroarenes. Mutat Res. 2001 Sep 20;496(1-2):75-81. PubMed PMID: 11551482.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Catechins are not major components responsible for anti-genotoxic effects of tea extracts against nitroarenes. AU - Ohe,T, AU - Marutani,K, AU - Nakase,S, PY - 2001/9/12/pubmed PY - 2001/9/28/medline PY - 2001/9/12/entrez SP - 75 EP - 81 JF - Mutation research JO - Mutat Res VL - 496 IS - 1-2 N2 - The anti-genotoxic properties of tea leaf extracts were examined in a Salmonella umu-test. Seven non-fermented teas (green tea), one semi-fermented tea (oolong tea), two fermented teas (black tea and Chinese pu er tea) and two other teas were examined for their anti-genotoxic abilities and for their catechins contents. This was to study the relationship between catechins contents and anti-genotoxic activity of various tea leaf extracts. All types of tea extracts showed more potent suppressive effects against umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK 1002 induced by four nitroarenes (1-nitropyrene, 2-nitrofluorene, 3-nitrofluoranthene and a mixture of 1,6- and 1,8-dinitropyrene) rather than 4-NQO, AF-2 and MNNG. The anti-genotoxic effect of 12 tea leaf extracts on 1-NP, 2-NF, 3-NF and DNP decreased in the order: oolong tea (semi-fermented tea)>black tea (fermented tea)>sencha (non-fermented tea, an ordinary grade green tea)>tocyucya (other tea)>Chinese pu er tea (fermented tea). The amount of catechins (EGC, C, EGCG, EC and ECG) in various teas in decreasing order was non-fermented tea>semi-fermented tea>fermented tea>other tea. A remarkable feature was the effectiveness of black tea and Chinese pu er tea in suppressing the genotoxicity induced by nitroarenes, in spite of the fact that these fermented teas do not have high catechins contents. Statistical analysis showed that no significant (P<0.01) correlation was found between the anti-genotoxicity of tea extracts against nitroarenes and the catechins contents in tea leaf extracts. In further experiment, fractionation of sencha extract by HPLC revealed that anti-genotoxicity of the peak fraction corresponding to catechins accounted for <10% of the total anti-genotoxic activity of sencha extract against for 1-nitropyrene. These results suggest that catechins are not major components responsible for the anti-genotoxic effects of tea leaf extracts against direct-acting nitroarenes. SN - 0027-5107 UR - https://www.unboundmedicine.com/medline/citation/11551482/Catechins_are_not_major_components_responsible_for_anti_genotoxic_effects_of_tea_extracts_against_nitroarenes_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1383571801002200 DB - PRIME DP - Unbound Medicine ER -