Antigenotoxic and Apoptotic Activity of Green Tea Polyphenol Extracts on Hexavalent Chromium-Induced DNA Damage in Peripheral Blood of CD-1 Mice: Analysis with Differential Acridine Orange/Ethidium Bromide Staining

María Del Carmen García-Rodríguez,Megumi Monserrat Carvente-Juárez,Mario Agustín Altamirano-Lozano

doi:10.1155/2013/486419

María Del Carmen García-Rodríguez, Megumi Monserrat Carvente-Juárez + Show 1 more

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https://doi.org/10.1155/2013/486419

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Abstract

This study was conducted to investigate the modulating effects of green tea polyphenols on genotoxic damage and apoptotic activity induced by hexavalent chromium [Cr (VI)] in CD-1 mice. Animals were divided into the following groups: (i) injected with vehicle; (ii) treated with green tea polyphenols (30 mg/kg) via gavage; (iii) injected with CrO3 (20 mg/kg) intraperitoneally; (iv) treated with green tea polyphenols in addition to CrO3. Genotoxic damage was evaluated by examining micronucleated polychromatic erythrocytes (MN-PCEs) obtained from peripheral blood at 0, 24, 48, and 72 h after treatment. Induction of apoptosis and cell viability were assessed by differential acridine orange/ethidium bromide (AO/EB) staining. Treatment of green tea polyphenols led to no significant changes in the MN-PCEs. However, CrO3 treatment significantly increased MN-PCEs at 24 and 48 h after injection. Green tea polyphenols treatment prior to CrO3 injection led to a decrease in MN-PCEs compared to the group treated with CrO3 only. The average of apoptotic cells was increased at 48 h after treatment compared to control mice, suggesting that apoptosis could contribute to eliminate the DNA damaged cells induced by Cr (VI). Our findings support the proposed protective effects of green tea polyphenols against the genotoxic damage induced by Cr (VI).

Highlights

Green tea (Camellia sinensis) is one of the most ancient beverages, consumed by over two-thirds of the world’s population
As part of our research program that evaluates chemopreventive and chemoprotective components in the diet, to obtain a more efficient modulation of the genotoxic damage induced by Cr (VI) in vivo, we directly studied green tea polyphenol extracts that contain a mixture of polyphenolic compounds, and we analyzed its apoptotic activity in the peripheral blood of CD-1 mice using analysis with differential acridine orange/ethidium bromide staining
Vehicle and green tea polyphenol extract did not modify the average number of induced micronucleated polychromatic erythrocytes (MN-PCEs) in the treated mice

Summary

Introduction

Green tea (Camellia sinensis) is one of the most ancient beverages, consumed by over two-thirds of the world’s population. The tannins encompass a variety of polyphenolic compounds, including important flavonoids such as catechins: (−)-epicatechin (EC), (−)-epigallocatechin (EGC) and their gallate forms (+) gallocatechin (GC), (−) epicatechin-3gallate (ECG) and (−) epigallocatechin-3-gallate (EGCG) [1, 2]. These compounds are chemically classified as dibenzpyrans, pyrones, and their derivatives. The primary flavonoids found in fresh green tea leaves are catechins (flavan-3-ols or flavanols) and the flavonols (Figures 1(b) and 1(c), resp.) [1]. Green tea contains other polyphenols such as theaflavins (Figure 1(d)) but at lower concentration than catechins. The polyphenols are naturally found in fruits and vegetables, as well as in drinks such as red wine and beer [1, 2]

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