Next Article in Journal
A New Member of Gamma-Conotoxin Family Isolated from Conus princeps Displays a Novel Molecular Target
Next Article in Special Issue
Ovatodiolide Inhibits Breast Cancer Stem/Progenitor Cells through SMURF2-Mediated Downregulation of Hsp27
Previous Article in Journal
Diminished but Not Abolished Effect of Two His351 Mutants of Anthrax Edema Factor in a Murine Model
Previous Article in Special Issue
Chemical Characterization and in Vitro Cytotoxicity on Squamous Cell Carcinoma Cells of Carica Papaya Leaf Extracts
Article Menu
Issue 2 (February) cover image

Export Article

Open AccessFeature PaperArticle
Toxins 2016, 8(2), 37; doi:10.3390/toxins8020037

Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen Species

1
Department of Biochemistry, Faculty of Life Sciences, AMU, Aligarh 202002, India
2
UoN Chair of Oman’s Medicinal Plants and Marine Natural Products, University of Nizwa, Birkat Al Mauz, PO Box 33, Postal Code 616, Nizwa, Oman
3
Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah 21589, Saudi Arabia
4
Karmanos Cancer Institute and Wayne State School of Medicine, Detroit, MI 48201, USA
*
Authors to whom correspondence should be addressed.
Academic Editor: Carmela Fimognari
Received: 2 January 2016 / Revised: 23 January 2016 / Accepted: 26 January 2016 / Published: 4 February 2016
(This article belongs to the Special Issue Dietary and Non-Dietary Phytochemicals and Cancer)
View Full-Text   |   Download PDF [4095 KB, uploaded 5 February 2016]   |  

Abstract

Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C), epicatechin (EC), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG) are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS) responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells. View Full-Text
Keywords: catechins; prooxidant; anticancer; copper; DNA breakage; reactive oxygen species; epicatechin; epigallocatechin; epigallocatechin-3-gallate catechins; prooxidant; anticancer; copper; DNA breakage; reactive oxygen species; epicatechin; epigallocatechin; epigallocatechin-3-gallate
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Farhan, M.; Khan, H.Y.; Oves, M.; Al-Harrasi, A.; Rehmani, N.; Arif, H.; Hadi, S.M.; Ahmad, A. Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen Species. Toxins 2016, 8, 37.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Toxins EISSN 2072-6651 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top