Interactions between Reactive Oxygen Species and Cancer: the Roles of Natural Dietary Antioxidants and their Molecular Mechanisms of Action

Reactive oxygen species (ROS) are natural products inevitably generated along with cellular metabolism.Due to their extreme reactivity, they can damage DNA, proteins and lipids. Dietary antioxidants have beenshown to take part in cellular reduction-oxidation (redox) reactions in which they can act as either antioxidants(election donors) or pro-oxidants (election acceptors) depending on the physiological environment and generaloxidative state. Organisms have developed efficient machinery and mechanisms to keep the production of ROSunder tight control, these same mechanisms have also been found to regulate other intracellular processes. p53is a sequence-specific transcription factor and critical tumour suppressor gene that is most frequently mutatedin human cancer. Cancer, one of the leading causes of death worldwide, can now be ameliorated, blocked orreversed with ubiquitous polyphenolic and organosulphur compounds present in natural dietary antioxidants.