Bioactive Polyphenols and Neuromodulation: Molecular Mechanisms in Neurodegeneration

Abstract

The interest in dietary polyphenols in recent years has greatly increased due to their antioxidant bioactivity with preventive properties against chronic diseases. Polyphenols, by modulating different cellular functions, play an important role in neuroprotection and are able to neutralize the effects of oxidative stress, inflammation, and apoptosis. Interestingly, all these mechanisms are involved in neurodegeneration. Although polyphenols display differences in their effectiveness due to interindividual variability, recent studies indicated that bioactive polyphenols in food and beverages promote health and prevent age-related cognitive decline. Polyphenols have a poor bioavailability and their digestion by gut microbiota produces active metabolites. In fact, dietary bioactive polyphenols need to be modified by microbiota present in the intestine before being absorbed, and to exert health preventive effects by interacting with cellular signalling pathways. This literature review includes an evaluation of the literature in English up to December 2019 in PubMed and Web of Science databases. A total of 307 studies, consisting of research reports, review articles and articles were examined and 146 were included. The review highlights the role of bioactive polyphenols in neurodegeneration, with a particular emphasis on the cellular and molecular mechanisms that are modulated by polyphenols involved in protection from oxidative stress and apoptosis prevention.

Effect of Cocoa and Cocoa Products on Cognitive Performance in Young Adults

“…Consistent findings from several studies confirm that these natural compounds can induce a positive effect on several cognitive processes, specifically executive function, attention, working memory, and processing speed [13]. Moreover, polyphenols can also exert neuroprotective functions due to their effectiveness against oxidative stress and inflammation as well as their capacity to modulate prosurvival or antiapoptotic Nutrients 2020, 12, 3691 2 of 14 signaling pathways [14]. Interestingly, better beneficial effects of polyphenols on brain plasticity biomarkers and on different cognitive functions have been found in young and middle-aged adults than in elderly [12,15], suggesting that young people can be an attractive population target to prevent onset of age-related diseases and cognitive decline.…”

Flavonoids as Potential Drugs for VPS13-Dependent Rare Neurodegenerative Diseases

“…Interestingly, luteolin restored the growth of vps13 cells regardless of the presence of multiple copies of FET4 ; thus, the effect of these two factors was not additive, suggesting that they act on the same process. Possible mechanisms of flavonoids and iron action involve binding to specific proteins, affecting metabolic or signaling pathways, or changing gene expression to induce a protective response in cells against SDS stress [ 63 , 64 ].…”

Nanoformulations to Enhance the Bioavailability and Physiological Functions of Polyphenols

“…With the continuous improvement of medical standards, the average life span of humans has been significantly extended, but correspondingly, diseases related to brain aging caused by an aging population have also increased significantly, such as cognitive and neurodegenerative diseases [ 109 ]. Neurodegenerative diseases, characterized by the progressive loss of functions of a large number of neurons and neural stem cells, leading to sensory deficits and cognitive impairments, are a type of progressive, disabling and severely fatal complex disease [ 110 ]. Studies have found that all neurodegenerative diseases share a common cellular and molecular mechanism, that is, oxidative stress accumulation, inflammation, protein misfolding and aggregation, neurotoxicity, etc.…”