Polyphenols In Human Health Research Articles

The emerging role of dark berry polyphenols in human health and nutrition

AbstractDark berry fruits are one of the top 10 richest sources of dietary polyphenols and have been examined for their pharmacokinetic benefits in the human body related to absorption, digestion, metabolism, and excretion (ADME). With the expansion of the world wide web and rise of discretionary income in Europe and North America impacting the global food trade during the 21st century, several species of berries have become available for general consumption that may have previously been out of reach of the average consumer. Compared to their commercial counterparts, these berries contain many of the same polyphenols, and the possibility exists for the discovery of novel phenolic compounds that may affect the ADME process in a host‐beneficial way. Several species have demonstrated antioxidant, antiobesogenic, antimicrobial, and anti‐inflammatory properties through in vitro, animal studies, and human clinical trials. This review examines the available chemical compositions of several dark berries and their effect on the ADME process, their implication in host health effects, and the potential of these emerging species to suggest areas for future research.

Polyphenols: From Theory to Practice.

Background: The importance of polyphenols in human health is well known; these compounds are common in foods, such as fruits, vegetables, spices, extra virgin olive oil and wine. On the other hand, the different factors that modulate the biological activity of these compounds are less well known. Conceptualization of the work: In this review we took into account about 200 relevant and recent papers on the following topics: “polyphenols bioavailability”, “polyphenols matrix effect”, “food matrix effect”, “polyphenols-cytochromes interaction”, after having reviewed and updated information on chemical classification and main biological properties of polyphenols, such as the antioxidant, anti-radical and anti-inflammatory activity, together with the tricky link between in vitro tests and clinical trials. Key findings: the issue of polyphenols bioavailability and matrix effect should be better taken into account when health claims are referred to polyphenols, thus considering the matrix effect, enzymatic interactions, reactions with other foods or genetic or gender characteristics that could interfere. We also discovered that in vitro studies often underrate the role of phytocomplexes and thus we provided practical hints to describe a clearer way to approach an investigation on polyphenols for a more resounding transfer to their use in medicine.

Fisetin Attenuates Lipopolysaccharide-Induced Inflammatory Responses in Macrophage.

Several studies have reported the efficacy and safety of polyphenols in human health; however, the verification of their efficacy remains insufficient. The aim of this study was to examine whether fisetin, one of flavonoids prevalently present in fruits and vegetables, could suppress lipopolysaccharide- (LPS-) induced inflammatory responses in macrophages. LPS increased proinflammatory mRNA abundance (MCP 1, IL-1β, and iNOS) but were suppressed by fisetin. The increment of nitric oxide by LPS, an oxidative stress factor, was attenuated by fisetin. In addition, LPS-enhanced phosphorylation of mitogen-activated protein kinase (ERK and JNK) was reduced. Finally, fisetin attenuated the expression or activity of uPA, uPAR, MMP-2, and MMP-9, which are known as associated factors of macrophage recruitment or infiltration. In conclusion, fisetin is a promising therapeutic agent for macrophage-related inflammation diseases, like sepsis and atherosclerosis.

Processing influences on food polyphenol profiles and biological activity

Increasing evidence supports the role of polyphenols in human health and has driven interest in translation of polyphenol rich ingredients to human foods. Food processing is a critical tool in development of consumer products aligned with clinical benefits. It is critical to consider how food processing may alter stability, bioavailability and ultimate biological activity of polyphenols. This review highlights processing parameters documented to impact polyphenol stability and provides examples of how select food processes impact polyphenols. Recent studies on whole grains, tea and fruit beverages document process induced losses as well as modification of bioavailability. However, characterization of processes-derived polyphenol degradation products is limited. Furthermore, bioactivity alterations remain mostly based on in vitro/preclinical systems. Growing evidence that polyphenol–macronutrient interactions can impact polyphenol profiles, bioavailability and bioactivities, including interactions with microbiota, suggest that consideration of the broader food matrix is critical in translation of experimental concepts to human foods.

Absorption and metabolites of anthocyanins and phenolic acids after consumption of purple wheat crackers and bars by healthy adults

The physiological effects of polyphenols in human health are dependent on their bioavailability and metabolism. The aim of this study was to determine anthocyanin and phenolic acid metabolites and their absorption following acute consumption of two purple wheat products by healthy adults. A secondary objective was to track changes in plasma antioxidant status and short-term markers of inflammation postprandially for 8 h. Anthocyanin and phenolic acid metabolites were quantified in the plasma and urine of 16 healthy female and male participants following the consumption of 4 servings of bran-enriched purple wheat bars and crackers containing 6.7 mg anthocyanins and 176–213 mg total phenolic acids. A few anthocyanin metabolites were detected in the urine and none were found in plasma. Ferulic acid was detected in plasma and urine, while hippuric acid was the major metabolite in the urine. The maximum plasma concentration of ferulic acid and phenolic acid metabolites reached 9–31 and 765-745 ng/mL within 30–60 min following products consumption. With acute consumption of purple wheat bars and crackers by healthy adults, rapid absorption and excretion of anthocyanin and phenolic acid metabolites was observed with no short-term impacts on plasma antioxidant activity or the inflammatory biomarkers, IL-6 and TNF-α.

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

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.

Comprehensive evaluation of phenolic profile in dark chocolate and dark chocolate enriched with Sakura green tea leaves or turmeric powder

Recently, a huge number of studies have confirmed the important role of chocolate polyphenols in human health, underlining its beneficial effects especially in the treatment of cardiovascular diseases. However, a thorough evaluation of chocolate phenolic profile is still lacking. This study aimed at a comprehensive characterization of dark chocolate phenolic profile, using non-targeted mass spectrometry identification. This approach allowed a tentative identification of 158 individual phenolic compounds: 67 were newly detected in dark chocolate, among these 38 were observed for the first time in chocolate as well as in cocoa beans or products. Ellagitannins, which have never been reported in cocoa or chocolate, represented about the 10% of the phenolic profile of dark chocolate. The enrichment of dark chocolate with Sakura green tea leaves or turmeric powder influenced and modified the phenolic profile, resulting in a phenolic concentration increase. In this way, this functional chocolate might maximize the beneficial effect of chocolate consumption, combining the positive health effects of chocolate, turmeric and green tea and, at the same time, reducing the amount of sugars and calories introduced with chocolate.

Plant-Derived Polyphenols in Human Health: Biological Activity, Metabolites and Putative Molecular Targets.

Hibiscus sabdariffa, Lippia citriodora, Rosmarinus officinalis and Olea europaea, are rich in bioactive compounds that represent most of the phenolic compounds' families and have exhibited potential benefits in human health. These plants have been used in folk medicine for their potential therapeutic properties in human chronic diseases. Recent evidence leads to postulate that polyphenols may account for such effects. Nevertheless, the compounds or metabolites that are responsible for reaching the molecular targets are unknown. data based on studies directly using complex extracts on cellular models, without considering metabolic aspects, have limited applicability. In contrast, studies exploring the absorption process, metabolites in the blood circulation and tissues have become essential to identify the intracellular final effectors that are responsible for extracts bioactivity. Once the cellular metabolites are identified using high-resolution mass spectrometry, docking techniques suppose a unique tool for virtually screening a large number of compounds on selected targets in order to elucidate their potential mechanisms. we provide an updated overview of the in vitro and in vivo studies on the toxicity, absorption, permeability, pharmacokinetics and cellular metabolism of bioactive compounds derived from the abovementioned plants to identify the potential compounds that are responsible for the observed health effects. we propose the use of targeted metabolomics followed by in silico studies to virtually screen identified metabolites on selected protein targets, in combination with the use of the candidate metabolites in cellular models, as the methods of choice for elucidating the molecular mechanisms of these compounds.

Understanding metabolic conversions and molecular actions of flavonoids in vivo:toward new strategies for effective utilization of natural polyphenols in human health

Many papers have suggested the health-beneficial activity of natural dietary polyphenols to prevent chronic diseases and aging processes in humans. It is generally recognized that polyphenols are absorbed from the intestines and metabolized into the phase-Ⅱ conjugates, i.e., the glucuronides and sulfates. For example, a major dietary flavonoid, quercetin, abundant in onion and buckwheat, is metabolized after oral intake into its conjugates, such as quercetin-3-O-glucuronide and quercetin-3'-O-sulfate, whereas no aglycone was found in the human plasma. Therefore, to understand the mechanisms of the biological activity of quercetin in vivo, we should focus on the molecular actions of these conjugates. In the last decade, we have demonstrated the unique actions of quercetin-3-O-glucuronide at sites of inflammation, including specific accumulation in macrophages and the following deconjugation into active aglycone, catalyzed by the macrophage-derived β-glucuronidase. This review summarizes recent findings regarding the anti-inflammatory mechanisms of quercetin conjugates in macrophages and propose a possible strategy for the effective utilization of natural polyphenols in our daily diet for prevention of age-related chronic diseases. J. Med. Invest. 65:162-165, August, 2018.

Pomegranate ellagitannins stimulate growth of gut bacteria in vitro: Implications for prebiotic and metabolic effects

The present study investigated the effect of pomegranate extract (POMx) and pomegranate juice (POM juice) on the growth of major groups of intestinal bacteria: Enterobacteriaceae, Bacteroides fragilis group, clostridia, bifidobacteria, and lactobacilli, and the utilization of pomegranate polyphenols by Bifidobacterium and Lactobacillus. The total phenolic content of the pomegranate extract and juice was determined using the Folin-Ciocalteau colorimetric method and reported as gallic acid equivalent (GAE). The polyphenol composition was determined by HPLC. Stool specimens were incubated with 400, 100, and 25 μg/ml GAE POMx and POM juice and subjected to selective culture. Bifidobacterium and Lactobacillus strains were incubated with 400 μg/ml GAE POMx and POM juice and metabolites were analyzed. POMx and POM juice increased the mean counts of Bifidobacterium and Lactobacillus and significantly inhibited the growth of B. fragilis group, clostridia, and Enterobacteriaceae in a dose–response manner. Bifidobacterium and Lactobacillus utilized ellagic acid and glycosyl ellagic acid but little or no punicalin was utilized. Neither POMx nor POM juice was converted to urolithins by the test bacteria or the in vitro stool cultures. The effect of pomegranate on the gut bacteria considered to be beneficial (Bifidobacterium and Lactobacillus) suggests that pomegranate may potentially work as a prebiotic. The concept that polyphenols such as those in pomegranate impact gut microbiota populations may establish a new role for polyphenols in human health.

Novel Function of Polyphenols in Human Health: A Review

Novel Function of Polyphenols in Human Health: A Review

Protection by Polyphenols of Postprandial Human Plasma and Low-Density Lipoprotein Modification: The Stomach as a Bioreactor

Recent studies dramatically showed that the removal of circulating modified low-density lipoprotein (LDL) results in complete prevention of atherosclerosis. The gastrointestinal tract is constantly exposed to food, some of it containing oxidized compounds. Lipid oxidation in the stomach was demonstrated by ingesting heated red meat in rats. Red wine polyphenols added to the rats' meat diet prevented lipid peroxidation in the stomach and absorption of malondialdehyde (MDA) in rat plasma. In humans, postprandial plasma MDA levels rose by 3-fold after a meal of red meat cutlets. MDA derived from meat consumption caused postprandial plasma LDL modification in human. The levels of plasma MDA showed a 75% reduction by consumption of red wine polyphenols during the meat meal. Locating the main biological site of action of polyphenols in the stomach led to a revision in the understanding of how antioxidants work in vivo and may help to elucidate the mechanism involved in the protective effects of polyphenols in human health.

Effects of natural antioxidants in neurodegenerative disease

Polyphenols are secondary metabolites with antioxidant properties and are abundant in the diet. Fruits, vegetables, herbs, and various drinks (tea, wine, and juices) are all sources of these molecules. Despite their abundance, investigations into the benefits of polyphenols in human health have only recently begun. Phenolic compounds have received increasing interest because of numerous epidemiological studies. These studies have suggested associations between the consumption of polyphenol-rich aliments and the prevention of chronic diseases, such as cancer, cardiovascular diseases, and neurodegenerative diseases.More specifically, in the last 10 years literature on the neuroprotective effects of a polyphenol-rich diet has grown considerably. It has been demonstrated, in various cell culture and animal models, that these metabolites are able to protect neuronal cells by attenuating oxidative stress and damage. However, it remains unclear as to how these compounds reach the brain, what concentrations are necessary, and what biologically active forms are needed to exert beneficial effects. Therefore, further research is needed to identify the molecular pathways and intracellular targets responsible for polyphenol's neuroprotective effects. The aim of this paper is to present various well-known dietary polyphenols and their mechanisms of neuroprotection with an emphasis on Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.

Determination and comparison of the total polyphenol contents of fresh and commercial fruit juices

PurposeThis paper aims to study the importance of polyphenols in human health and, based on recommendations on the replacement of carbonated drinks with nutritious beverages, like fruit juices, seeks to compare the polyphenol contents of natural and commercial juices.Design/methodology/approachThe total polypheol content of 39 fresh and 159 commercial (100 percent and less than 50 percent) fruit juices was analyzed by the terbium sensitized fluorescence method. The ANOVA with Tukey post hoc test, and also an independent t‐test, were used for statistical analyses.FindingsThe mean polyphenol contents of fresh juices were significantly (p<0.001) higher than those of 100 percent commercials (5.34±2.7 vs 3.28±0.86 mg/l). In fresh juices the concentration ranged from 1.06±0.08 (pineapple) to 10.14±0.07 (sour cherry) mg QE/100 ml, while in 100 percent commercial juices the range was from 2.37±0.05 (orange) to 5.34±0.4 (pomegranate) mg QE/100 ml, and in <50 percent commercial juices they ranged from 1.04±0.7 (red grape) to 2.21±0.07 (white grape) mg QE/100 ml. The polyphenol contents of dark juices, in both fresh and commercial products, were significantly higher than others (p<0.001) and most fresh fruit juices possessed higher amounts of polyphenol than commercial ones. Although various juices differed in the quantity of total polyphenol, they can be considered as a good source of functional beverage.Originality/valueThis paper provides information about the polyphenol content of fresh and commercial (100 percent and <50 percent) fruit juices. To the best of the authors' knowledge, there have been no articles which aim to compare the polyphenol content of Iranian fresh and commercial fruit juices. For analysing the polyphenol contents, the newly developed terbium sensitized fluorescence method was used, and also the applicability of this new method was compared with the commonly used Folin‐Ciocalteau method.

A New Laccase Biosensor For Polyphenols Determination

The relevance of polyphenols in human health is a well known fact. Prompted by that, a very intensive research has been directed to get a method to detect them, wich will improve the current ones. Laccase (p-diphenol:dioxygen oxidoreductase EC 1.10.3.2) is a multi-copper oxidase, wich couples catalytic oxidation of phenolic substrates with four electron reduction of dioxygen to water [1]. A maximum catalytic response in oxigenated electrolyte was observed between 4.5 and 5.5 [2], while for pH > 6.9 the laccase was found to be inactive [3]. We prepared a biosensor with laccase immobilised on a polyether sulphone membrane, at pH 4.5, wich was applied at Universal Sensors base electrode. Reduction of the product of oxidation of several polyphenols, catalysed by laccase, was done at a potential for wich the polyphenol of interest was found to respond. Reduction of catechol was found to occur at a potential of -200mV, wich is often referred to in the literature for polyphenolic biosensors. However other polyphenols did not respond at that potential. It was observed that (+)- catechin produced a very large cathodic current when +100mV were applied to the laccase biosensor, both in aqueous acetate and 12% ethanol acetate buffer, whereas caffeic acid responded at -50mV. Other polyphenols tested were gallic acid, malvidin, quercetin, rutin, trans-resveratrol