Polyphenols are secondary metabolites of plants and are generally involved in defense against ultraviolet radiation or aggression by pathogens. In the last decade, there has been much interest in the potential health benefits of dietary plant polyphenols as antioxidant. Epidemiological studies and associated meta-analyses strongly suggest that long term consumption of diets rich in plant polyphenols offer protection against development of cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases. Here we present knowledge about the biological effects of plant polyphenols in the context of relevance to human health.

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Plant Polyphenols as Dietary Antioxidants in Human Health and Disease

This narrative mini- review summarizes current knowledge of the role of polyphenols in health outcomes-and non-communicable diseases specifically-and discusses the implications of this evidence for public health, and for future directions for public health practice, policy, and research The publications cited originate mainly from animal models and feeding experiments, as well as human cohort and case-control studies Hypothesized protective effects of polyphenols in acute and chronic diseases, including obesity, neurodegenerative diseases, type 2 diabetes, and cardiovascular diseases, are evaluated Potential harmful effects of some polyphenols are also considered, counterbalanced with the limited evidence of harm in the research literature Recent international governmental regulations are discussed, as the safety and health claims of only a few specific polyphenolic compounds have been officially sanctioned The implications of food processing on the bioavailability of polyphenols are also assessed, in addition to the health claims and marketing of polyphenols as a functional food Finally, this mini-review asserts the need for increased regulation and guidelines for polyphenol consumption and supplementation in order to ensure consumers remain safe and informed about polyphenols

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The Role of Polyphenols in Human Health and Food Systems: A Mini-Review.

The oxidative stress imposed by reactive oxygen species (ROS) plays an important role in many chronic and degenerative diseases. As an important category of phytochemicals, phenolic compounds universally exist in plants, and have been considered to have high antioxidant ability and free radical scavenging capacity, with the mechanism of inhibiting the enzymes responsible for ROS production and reducing highly oxidized ROS. Therefore, phenolic compounds have attracted increasing attention as potential agents for preventing and treating many oxidative stress-related diseases, such as cardiovascular diseases, cancer, ageing, diabetes mellitus and neurodegenerative diseases. This review summarizes current knowledge of natural polyphenols, including resource, bioactivities, bioavailability and potential toxicity.

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Resources and biological activities of natural polyphenols.

“Let food be thy medicine and medicine be thy food” was expressed by Hippocrates more than 2000 years ago and the health benefits of natural food products have been considered for different goals s...

https://www.tandfonline.com/doi/pdf/10.1080/10942912.2017.1354017

Polyphenols and their benefits: A review

The nuclear factor-kappaB (NF-kappaB) pathway is one of the most important cellular signal transduction pathways involved in both physiologic processes and disease conditions. It plays important roles in the control of immune function, inflammation, stress response, differentiation, apoptosis, and cell survival. Moreover, NF-kappaB is critically involved in the processes of development and progression of cancers. More importantly, recent studies have shown that NF-kappaB signaling also plays critical roles in the epithelial-mesenchymal transition (EMT) and cancer stem cells. Therefore, targeting of NF-kappaB signaling pathway could be a potent strategy for the prevention and/or treatment of human cancers and inflammatory diseases.

NF-kappaB signaling pathway and its therapeutic implications in human diseases.

Brain aging and the most diffused neurodegenerative diseases of the elderly are characterized by oxidative damage, redox metals homeostasis impairment and inflammation Food polyphenols can counteract these alterations in vitro and are therefore suggested to have potential anti-aging and brain-protective activities, as also indicated by the results of some epidemiological studies Despite the huge and increasing amount of the in vitro studies trying to unravel the mechanisms of action of dietary polyphenols, the research in this field is still incomplete, and questions about bioavailability, biotransformation, synergism with other dietary factors, mechanisms of the antioxidant activity, risks inherent to their possible pro-oxidant activities are still unanswered Most of all, the capacity of the majority of these compounds to cross the blood-brain barrier and reach brain is still unknown This commentary discusses recent data on these aspects, particularly focusing on effects of curcumin, resveratrol and catechins on Alzheimer's disease

S. Mazzitelli

Papers

Benefits from Dietary Polyphenols for Brain Aging and Alzheimer’s Disease