title: Prooxidant Activity of Polyphenols, Flavonoids, Anthocyanins and Carotenoids: Updated Review of Mechanisms and Catalyzing Metals.
abstract: Natural antioxidants, including polyphenols, flavonoids, anthocyanins and carotenoids, play an important role in the treatment and prevention of a large number of diseases. However, studies indicate that natural antioxidants can act as prooxidants, which produce free radicals and cause DNA damage and mutagenesis. The prooxidant activity is typically catalyzed by metals, particularly transition metals such as Fe and Cu, present in biological systems. In this article, we aim to review new in vitro and in vivo evidence of the prooxidant activity of phenolics, flavonoids, anthocyanins and carotenoids. We highlight the role of catalyzing metals, including transition metals, non-transition metals and metalloids, in the prooxidant activity of natural antioxidants. Prooxidant structure-activity relationships of simple phenolics, flavonoids and anthocyanins and the role of cellular antioxidant defense, including endogenous antioxidant compounds and antioxidant enzymes, are also addressed in this review. In addition, we discuss the question, With respect to in vitro evidence of the prooxidant activity of antioxidants, can we translate this activity into biological systems and the human body? Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Science, Mashhad, Iran.
authors.forename: Samira
authors.initials: S
authors.lastname: Eghbaliferiz
authors.affiliation: Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Science, Mashhad, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Iranshahi
mesh_terms: D000872:Anthocyanins / Q000737:chemistry*; D000975:Antioxidants / Q000494:pharmacology; D002338:Carotenoids / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D006801:Humans; D008670:Metals / Q000737:chemistry*; D018384:Oxidative Stress; D059808:Polyphenols / Q000737:chemistry*; D017382:Reactive Oxygen Species; D013329:Structure-Activity Relationship
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D005419:Flavonoids; D008670:Metals; D059808:Polyphenols; D017382:Reactive Oxygen Species; D002338:Carotenoids
keywords: catechin; cyanidin; delphinidin; lycopene; prooxidant; tannins