Healthy Effects of Plant Polyphenols: Molecular Mechanisms

Abstract

The increasing extension in life expectancy of human beings in developed countries is accompanied by a progressively greater rate of degenerative diseases associated with lifestyle and aging, most of which are still waiting for effective, not merely symptomatic, therapies. Accordingly, at present, the recommendations aimed at reducing the prevalence of these conditions in the population are limited to a safer lifestyle including physical/mental exercise, a reduced caloric intake, and a proper diet in a convivial environment. The claimed health benefits of the Mediterranean and Asian diets have been confirmed in many clinical trials and epidemiological surveys. These diets are characterized by several features, including low meat consumption, the intake of oils instead of fats as lipid sources, moderate amounts of red wine, and significant amounts of fresh fruit and vegetables. In particular, the latter have attracted popular and scientific attention for their content, though in reduced amounts, of a number of molecules increasingly investigated for their healthy properties. Among the latter, plant polyphenols have raised remarkable interest in the scientific community; in fact, several clinical trials have confirmed that many health benefits of the Mediterranean/Asian diets can be traced back to the presence of significant amounts of these molecules, even though, in some cases, contradictory results have been reported, which highlights the need for further investigation. In light of the results of these trials, recent research has sought to provide information on the biochemical, molecular, epigenetic, and cell biology modifications by plant polyphenols in cell, organismal, animal, and human models of cancer, metabolic, and neurodegenerative pathologies, notably Alzheimer’s and Parkinson disease. The findings reported in the last decade are starting to help to decipher the complex relations between plant polyphenols and cell homeostatic systems including metabolic and redox equilibrium, proteostasis, and the inflammatory response, establishing an increasingly solid molecular basis for the healthy effects of these molecules. Taken together, the data currently available, though still incomplete, are providing a rationale for the possible use of natural polyphenols, or their molecular scaffolds, as nutraceuticals to contrast aging and to combat many associated pathologies.

Anti-inflammatory and Anti-oxidant Activity of Hidrox® in Rotenone-Induced Parkinson’s Disease in Mice

“…Vitagenes encode for the Hsps, HO-1 and sirtuin protein systems, whose activation is most likely dependent on Nrf2. In agreement with previously reported data from our laboratory, demonstrating the beneficial effects of HD against PD [ 27 ], we wanted to evaluate the effect of HD treatment on the activation of Nrf2 and consecutively on HO-1, Hsp-70 and Sirt-1 expression. Western blot analysis revealed a significant increase in Nrf2 in rotenone-treated mice.…”

“…Further research has shown that HT administration has been able to counteract the dysregulation of the signaling mechanisms in hippocampal neurons [ 24 , 25 , 26 ]. Recently, increasing evidence reports that HT and its derivates activate the phase 2 response, leading to the expression of the nuclear factor erythroid 2-related factor (Nrf2) antioxidant pathway [ 27 , 28 ]. Interestingly, Nrf2 represents a crucial mechanism of resistance to oxidative stress and inflammation in vitro and in vivo [ 29 , 30 ].…”

The Pathology of Parkinson’s Disease and Potential Benefit of Dietary Polyphenols

“…In fact, it is the polyphenols in these diets that are associated with the greatest reduction in neurodegeneration. Dietary polyphenols (see Figure 4 ) have multiple targets, including the inflammatory pathway, ROS, and alterations in proteostasis in disease states associated with amyloid dysfunction [ 93 ]. This could likely make them valuable in possible prevention strategies.…”

Annona cherimola Miller Fruit as a Promising Candidate against Diabetic Complications: An In Vitro Study and Preliminary Clinical Results

“…The daily intake of large quantities of fruit and vegetables, in addition to caloric restriction and regular exercise, is the basis of a healthy lifestyle and prevention of various chronic health problems. The high intake of phytonutrients (in particular, vitamins and plant phenols) can contribute to the reduction of the risk of various metabolic pathologies, including diabetes and related complications [ 18 , 19 ]. In this regard, there is a rich literature disclosing the benefits derived from the dietary consumption of tropical or subtropical fruits (such as mango, papaya, guava, and persimmon) [ 20 , 21 ].…”