Making sense of antioxidant–pro–oxidant conundrum in anticancer research

Abstract

Plant-derived dietary antioxidants have attracted considerable interest in recent past for their ability to induce apoptosis and regression of tumors in animal models. While it is believed that the antioxidant properties of these agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, it could not account for apoptosis induction and chemotherapeutic observations. We have provided a number of evidence that dietary antioxidants can alternatively switch to a pro-oxidant action in the presence of transition metals such as copper. Such a pro-oxidant action leads to strand breaks in cellular DNA and growth inhibition in cancer cells.