DNA breakage by tannic acid and Cu(II): sequence specificity of the reaction and involvement of active oxygen species

Bhat, Rashid; Hadi, S. M.

doi:10.1016/0165-1161(94)90031-0

Cited by 43 publications

(18 citation statements)

References 24 publications

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“…In addition, it is well established that a combination of various polyphenols is considerably more effective in cytotoxicity towards cancer cells than individual polyphenols alone (100). Studies in our laboratory have further shown that properties which form the basis of the above-described cytotoxic mechanism, such as DNA binding, Cu(II) reduction, mobilization of endogenous copper and generation of ROS, are common to several classes of polyphenols (55)(56)(57)(58)(59)63,64,67,69,75). We believe that such a common mechanism better explains the anti-cancer effects of polyphenols with diverse chemical structures as also the preferential cytotoxicity towards cancer cells.…”

Section: Resultsmentioning

confidence: 86%

“…It has been shown that polyphenols auto-oxidize in cell culture media to generate H 2 O 2 that can enter cells/nuclei, causing damage to various macromolecules (68). In order to exclude this possibility in our system, we have determined the resveratrol-induced formation of H 2 O 2 in the incubation medium of isolated nuclei (0.4M phosphate buffer) (65) and also compared it with a known generator of H 2 O 2 , namely tannic acid (69). The results showed that the rate of H 2 O 2 formation by resveratrol was almost negligible, but that of tannic acid was quite significant.…”

Section: Mobilization Of Nuclear Copper By Resveratrolmentioning

confidence: 99%

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Resveratrol Mobilizes Endogenous Copper in Human Peripheral Lymphocytes Leading to Oxidative DNA Breakage: A Putative Mechanism for Chemoprevention of Cancer

et al. 2010

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Plant polyphenols are important components of human diet, and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring anti-oxidants but also act as pro-oxidants catalyzing DNA degradation in the presence of metal ions such as copper. The plant polyphenol resveratrol confers resistance to plants against fungal agents and has been implicated as a cancer chemopreventive agent. Of particular interest is the observation that resveratrol has been found to induce apoptosis in cancer cell lines but not in normal cells. Over the last few years, we have shown that resveratrol is capable of causing DNA breakage in cells such as human lymphocytes. Such cellular DNA breakage is inhibited by copper specific chelators but not by iron and zinc chelating agents. Similar results are obtained by using permeabilized cells or with isolated nuclei, indicating that chromatin-bound copper is mobilized in this reaction. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and resveratrol to generate reactive oxygen species responsible for DNA cleavage. The results are in support of our hypothesis that anti-cancer mechanism of plant polyphenols involves mobilization of endogenous copper and the consequent pro-oxidant action. Such a mechanism better explains the anti-cancer effects of resveratrol, as it accounts for the preferential cytotoxicity towards cancer cells.

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Section: Resultsmentioning

confidence: 86%

Section: Mobilization Of Nuclear Copper By Resveratrolmentioning

confidence: 99%

Resveratrol Mobilizes Endogenous Copper in Human Peripheral Lymphocytes Leading to Oxidative DNA Breakage: A Putative Mechanism for Chemoprevention of Cancer

et al. 2010

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“…This may lead to extraneous production of ROS that could also account for cellular DNA breakage. In order to examine this possibility we have determined the formation of H 2 O 2 by isoflavones in the incubation medium and compared it with a known generator of H 2 O 2 , namely tannic acid [43]. In the results given in Fig.…”

Section: H 2 O 2 Generation By Isoflavones In the Incubation Mediummentioning

confidence: 99%

Cellular DNA breakage by soy isoflavone genistein and its methylated structural analogue biochanin A

Ullah

Shamim

Hanif

et al. 2009

Molecular Nutrition Food Res

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Epidemiological studies have indicated that populations with high isoflavone intake through soy consumption have lower rates of breast, prostate, and colon cancer. The isoflavone polyphenol genistein in soybean is considered to be a potent chemopreventive agent against cancer. In order to explore the chemical basis of chemopreventive activity of genistein, in this paper we have examined the structure-activity relationship between genistein and its structural analogue biochanin A. We show that both genistein and its methylated derivative biochanin A are able to mobilize nuclear copper in human lymphocyte, leading to degradation of cellular DNA. However, the relative rate of DNA breakage was greater in the case of genistein. Further, the cellular DNA degradation was inhibited by copper chelator (neocuproine/bathocuproine) but not by compounds that specifically bind iron and zinc (desferrioxamine mesylate and histidine, respectively). We also compared the antioxidant activity of the two isoflavones against tert-butylhydroperoxide-induced oxidative breakage in lymphocytes. Again genistein was found to be more effective than biochanin A in providing protection against oxidative stress induced by tert-butylhydroperoxide. It would therefore appear that the structural features of isoflavones that are important for antioxidant properties are also the ones that contribute to their pro-oxidant action through a mechanism that involves redox cycling of chromatin-bound nuclear copper.

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“…Radical-induced damage to DNA occurs at both the phosphate backbone (strand breakage) and nucleotide bases, and both of these sites of damage are widely used to quantitatively determine the extent of oxidative DNA damage [93][94][95][96][97][98][99][100][101]. Because the DNA backbone is composed of negatively charged phosphate groups, as well as electron-rich nucleotide bases, metal ions such as Na ?…”

Section: Oxidative Stress Dna Damage and The Fenton Reactionmentioning

confidence: 99%

A Review of the Antioxidant Mechanisms of Polyphenol Compounds Related to Iron Binding

Perron

Brumaghim

2009

Cell Biochem Biophys

1,071

775

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In this review, primary attention is given to the antioxidant (and prooxidant) activity of polyphenols arising from their interactions with iron both in vitro and in vivo. In addition, an overview of oxidative stress and the Fenton reaction is provided, as well as a discussion of the chemistry of iron binding by catecholate, gallate, and semiquinone ligands along with their stability constants, UV-vis spectra, stoichiometries in solution as a function of pH, rates of iron oxidation by O(2) upon polyphenol binding, and the published crystal structures for iron-polyphenol complexes. Radical scavenging mechanisms of polyphenols unrelated to iron binding, their interactions with copper, and the prooxidant activity of iron-polyphenol complexes are briefly discussed.

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DNA breakage by tannic acid and Cu(II): sequence specificity of the reaction and involvement of active oxygen species

Cited by 43 publications

References 24 publications

Resveratrol Mobilizes Endogenous Copper in Human Peripheral Lymphocytes Leading to Oxidative DNA Breakage: A Putative Mechanism for Chemoprevention of Cancer

Resveratrol Mobilizes Endogenous Copper in Human Peripheral Lymphocytes Leading to Oxidative DNA Breakage: A Putative Mechanism for Chemoprevention of Cancer

Cellular DNA breakage by soy isoflavone genistein and its methylated structural analogue biochanin A

A Review of the Antioxidant Mechanisms of Polyphenol Compounds Related to Iron Binding

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