The Hormetic Role of Dietary Antioxidants in Free Radical-Related Diseases

Abstract

Regular consumption of cruciferous vegetables or spices is associated with a reduced incidence of cancer and reduction of markers for neurodegenerative damage. Furthermore, greater health benefit may be obtained from raw as opposed to cooked vegetables. Nutritional interventions, by increasing dietary intake of fruits and vegetables, can retard and even reverse age-related declines in brain function and cognitive performance. The mechanisms through which dietary supplementation with antioxidants may be useful to prevent free radical-related diseases is related to their ability to counteract toxic production of both reactive oxygen and nitrogen species, along with the up-regulation of vitagenes, such as members of the heat shock protein (Hsp) family heme oxygenase-1 and Hsp70. The most prominent dietary factor that affects the risk of many different chronic diseases is energy intake - excessive calorie intake increases the risk. Reducing energy intake by controlled caloric restriction or intermittent fasting increases lifespan and protects various tissues against diseases, in part, by hormetic mechanisms that increase cellular stress resistance. This biphasic dose-response relationship, referred to here as hormesis, display low-dose stimulation and a high-dose inhibition. Despite the current interest in hormesis by the toxicology community, quantitatively similar U-shaped dose responses have long been recognized by researchers to be involved with factors affecting memory, learning, and performance, as well as nutritional antioxidants and oxidative stress-mediated degenerative reactions. Dietary polyphenols present strong cytoprotective effects, however under uncontrolled nutritional supplementation gene induction effects and the interaction with detoxification responses can have negative consequences through the generation of more reactive and harmful intermediates.

Low Grade Inflammation as a Common Pathogenetic Denominator in Age-Related Diseases: Novel Drug Targets for Anti-Ageing Strategies and Successful Ageing Achievement

“…The damaging effect occurs in biological systems when there is an overproduction of ROS/RNS on one side and a deficiency of enzymatic and non-enzymatic anti-oxidants on the other side. The harmful effect of redox regulation implicated diseases including cancer, diabetes mellitus, ischemia/reperfusion injury, inflammatory diseases, neurodegenerative disorders and ageing [137][138][139][140].…”

Therapeutic detoxification of quercetin against carbon tetrachloride-induced acute liver injury in mice and its mechanism

“…Some epidemiological surveys report that a negative correlation can be observed between dietary intake of flavonoids and cardiovascular disease or cancer (Muldoon and Kritchevsky, 1996;Yang et al, 2001). However, nutraceuticals, including flavonoids, may also have toxic effects depending on the dose and the redox status of the cell, which is also called as hormesis (Brambilla et al, 2008;Calabrese et al, 2010). Quercetin is a well-known flavonoid, and it is widely distributed in various Chinese medicinal herbs, such as Flos sophorae Immaturus (Kelly, 2011;Wu et al, 2012).…”

Antioxidant activity of different parts ofTetrataenium lasiopetalum

“…Therefore, the need to find natural and safe sources of antioxidants has notably increased (Alinezhad et al, 2012). Plant phenol constituents possess very good antioxidant activity and can protect cells against free radical-induced oxidative stress (Calabrese et al, 2010). According to chemical and structure analysis data, the presence of the conjugated ring structures and hydroxyl groups play an important role in antioxidant actions of plant phenol compounds (Kim et al, 2006).…”