Ellagitannins, urolithins, and neuroprotection: Human evidence and the possible link to the gut microbiota

Methylated urolithin A, mitigates cognitive impairment by inhibiting NLRP3 inflammasome and ameliorating mitochondrial dysfunction in aging mice

Effective therapeutic interventions for elderly patients are lacking, despite advances in pharmacotherapy. Methylated urolithin A (mUro A), a modified ellagitannin (ET)-derived metabolite, exhibits anti-inflammatory, antioxidative, and anti-apoptotic effects. Current research has primarily investigated the neuroprotective effects of mUroA in aging mice and explored the underlying mechanisms. Our study used an in vivo aging model induced by d-galactose (D-gal) to show that mUro A notably improved learning and memory, prevented synaptic impairments by enhancing synaptic protein expression and increasing EPSCs, and reduced oxidative damage in aging mice. mUro A alleviated the activation of the NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome, leading to reduced glial cell activity and neuroinflammation in both accelerated aging and naturally senescent mouse models. Moreover, mUroA enhanced the activity of TCA cycle enzymes (PDH, CS, and OGDH), decreased 8-OHdG levels, and raised ATP and NAD+ levels within the mitochondria. At the molecular level, mUro A decreased phosphorylated p53 levels and increased the expression of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), thus enhancing mitochondrial function. In conclusion, mUro A alleviates cognitive impairment in aging mice by suppressing neuroinflammation through NLRP3 inflammasome inhibition and restoring mitochondrial function via the p53-PGC-1α pathway. This suggests its potential therapeutic agent for brain aging and aging-related diseases.

Pomegranate polyphenol punicalagin as a nutraceutical for mitigating mild cognitive impairment: An overview of beneficial properties

Dementia treatment has become a global research priority, driven by the increase in the aging population. Punicalagin, the primary polyphenol found in pomegranate fruit, exhibits a variety of benefits. Today, a growing body of research is showing that punicalagin is a nutraceutical for the prevention of mild cognitive impairment (MCI). However, a comprehensive review is still lacking. The aim of this paper is to provide a comprehensive review of the physicochemical properties, origin and pharmacokinetics of punicalagin, while emphasizing the significance and mechanisms of its potential role in the prevention and treatment of MCI. Preclinical and clinical studies have demonstrated that Punicalagin possesses the potential to effectively target and enhance the treatment of MCI. Potential mechanisms by which punicalagin alleviates MCI include antioxidative damage, anti-neuroinflammation, promotion of neurogenesis, and modulation of neurotransmitter interactions. Overall, punicalagin is safer and shows potential as a therapeutic compound for the prevention and treatment of MCI, although more rigorous randomized controlled trials involving large populations are required.

Navigating neurological disorders: harnessing the power of natural compounds for innovative therapeutic breakthroughs

Novel treatments are needed as neurological issues become more frequent worldwide. According to the report, plants, oceans, microorganisms, and animals contain interesting drug discovery compounds. Alzheimer's, Parkinson's, and stroke reviews emphasize neurological disorders' complexity and natural substances' safety. Learn about marine-derived and herbal substances' neuroprotective characteristics and applications. Molecular pathways show these substances' neurological healing effects. This article discusses clinical usage of Bryostatin-1, Fucoidan, Icariin, Salvianolic acid, Curcumin, Resveratrol, etc. Their potential benefits for asthma and Alzheimer's disease are complex. Although limited, the study promotes rigorous scientific research and collaboration between traditional and alternative medical practitioners. Unexplored natural compounds, quality control, well-structured clinical trials, and interdisciplinary collaboration should guide future study. Developing and employing natural chemicals to treat neurological illnesses requires ethical sourcing, sustainability, and public awareness. This detailed analysis covers natural chemicals' current state, challenges, and opportunities in neurological disorder treatment. See also the graphical abstract(Fig. 1).

Urolithin A production drives the effects of pomegranate on the gut microbial metabolism of bile acids and cholesterol in mild dyslipidaemic overweight and obese individuals

The metabolism of (poly)phenols and some host metabolites, including bile acids (BAs) and cholesterol, varies among individuals depending on their gut microbiota. The gut microbial metabolism of ellagitannins (ETs) and ellagic acid (EA) produces urolithins (Uros), yielding three metabotypes with quantitative and qualitative differences based on dissimilar Uro-producing profiles (UM-A, UM-B, and UM-0, i.e., non-producers). Previous animal studies demonstrated that polyphenols impact BAs and cholesterol microbial metabolism, but data on their effects in humans and data regarding the inter-individual variability of these metabolic conversions are scant. We evaluated whether UMs, as distinctive functional gut-microbiome signatures, could determine the potential effect of a pomegranate extract (PE) rich in ET-EA on the metabolism of BAs and cholesterol in mild dyslipidaemic overweight-obese individuals, with possible consequences on host-lipid homeostasis and gut health. At the baseline, UM-B presented the highest levels of faecal total and secondary BAs and coprostanol, suggesting that the lipid absorption capacity and gut cytotoxic risk could be augmented in UM-B. PE intake significantly reduced faecal coprostanol and BA production, especially secondary BAs, and modulated the gut microbiome, reducing the gut cytotoxic risk, especially in UM-B individuals. The lowering of faecal microbial coprostanol and BAs and some BA-metabolising bacteria was quantitatively correlated with Uro concentrations, mainly faecal Uro-A. This suggests that PE consumption could exert cardiovascular and gut protection through Uro-A production as a direct driver of the effects and indirectly by reducing the Coriobacteriaceae family and BA pool, known factors involved in the gut absorption of lipids.

Improved Cardiovascular Effects of a Novel Pomegranate Byproduct Extract Obtained through Hydrodynamic Cavitation

The healthy properties of pomegranate fruit, a highly consumed food, have been known for a long time. However, the pomegranate supply chain is still rather inefficient, with the non-edible fraction, whose weight is roughly half the total and is endowed with plenty of valuable bioactive compounds, either disposed of or underutilized. A novel extract obtained from non-edible byproducts (called PPE), using hydrodynamic cavitation, a green, efficient, and scalable technique, was investigated for its cardiovascular effects in vivo. PPE showed efficacy in an acute phenylephrine (PE)-induced hypertensive rat model, similar to the extract of whole fruit (PFE) obtained using the same extractive technique, along with good intestinal bioaccessibility after oral administration. Finally, when chronically administered for 6 weeks to spontaneously hypertensive rats, PPE was shown to significantly contain the increase in systolic blood pressure, comparable to the reference drug Captopril, and at a dose remarkably lower than the reported effective dose of ellagic acid. The extract from the non-edible fraction of the pomegranate fruit also showed good anti-inflammation and anti-fibrotic effects. The findings of this study, along with the extraction technique, could contribute to enhancing the value of the pomegranate supply chain, relieve the related environmental burden, and potentially improve public health.

Epigenetics in obesity: Mechanisms and advances in therapies based on natural products

Obesity is a major risk factor for morbidity and mortality because it has a close relationship to metabolic illnesses, such as diabetes, cardiovascular diseases, and some types of cancer. With no drugs available, the mainstay of obesity management remains lifestyle changes with exercise and dietary modifications. In light of the tremendous disease burden and unmet therapeutics, fresh perspectives on pathophysiology and drug discovery are needed. The development of epigenetics provides a compelling justification for how environmental, lifestyle, and other risk factors contribute to the pathogenesis of obesity. Furthermore, epigenetic dysregulations can be restored, and it has been reported that certain natural products obtained from plants, such as tea polyphenols, ellagic acid, urolithins, curcumin, genistein, isothiocyanates, and citrus isoflavonoids, were shown to inhibit weight gain. These substances have great antioxidant potential and are of great interest because they can also modify epigenetic mechanisms. Therefore, understanding epigenetic modifications to target the primary cause of obesity and the epigenetic mechanisms of anti-obesity effects with certain phytochemicals can prove rational strategies to prevent the disease and develop novel therapeutic interventions. Thus, the current review aimed to summarize the epigenetic mechanisms and advances in therapies for obesity based on natural products to provide evidence for the development of several potential anti-obesity drug targets.

Mitophagy curtails cytosolic mtDNA-dependent activation of cGAS/STING inflammation during aging

Macroautophagy decreases with age, and this change is considered a hallmark of the aging process. It remains unknown whether mitophagy, the essential selective autophagic degradation of mitochondria, also decreases with age. In our analysis of mitophagy in multiple organs in the mito-QC reporter mouse, mitophagy is either increased or unchanged in old versus young mice. Transcriptomic analysis shows marked upregulation of the type I interferon response in the retina of old mice, which correlates with increased levels of cytosolic mtDNA and activation of the cGAS/STING pathway. Crucially, these same alterations are replicated in primary human fibroblasts from elderly donors. In old mice, pharmacological induction of mitophagy with urolithin A attenuates cGAS/STING activation and ameliorates deterioration of neurological function. These findings point to mitophagy induction as a strategy to decrease age-associated inflammation and increase healthspan.

Understanding mechanisms of antioxidant action in health and disease

Several different reactive oxygen species (ROS) are generated in vivo. They have roles in the development of certain human diseases whilst also performing physiological functions. ROS are counterbalanced by an antioxidant defence network, which functions to modulate ROS levels to allow their physiological roles whilst minimizing the oxidative damage they cause that can contribute to disease development. This Review describes the mechanisms of action of antioxidants synthesized in vivo, antioxidants derived from the human diet and synthetic antioxidants developed as therapeutic agents, with a focus on the gaps in our current knowledge and the approaches needed to close them. The Review also explores the reasons behind the successes and failures of antioxidants in treating or preventing human disease. Antioxidants may have special roles in the gastrointestinal tract, and many lifestyle features known to promote health (especially diet, exercise and the control of blood glucose and cholesterol levels) may be acting, at least in part, by antioxidant mechanisms. Certain reactive sulfur species may be important antioxidants but more accurate determinations of their concentrations in vivo are needed to help assess their contributions.

Pharmacomicrobiomics of cell-cycle specific anti-cancer drugs - is it a new perspective for personalized treatment of cancer patients?

Intestinal bacteria are equipped with an enzyme apparatus that is involved in the active biotransformation of xenobiotics, including drugs. Pharmacomicrobiomics, a new area of pharmacology, analyses interactions between bacteria and xenobiotics. However, there is another side to the coin. Pharmacotherapeutic agents can significantly modify the microbiota, which consequently affects their efficacy. In this review, we comprehensively gathered scientific evidence on the interplay between anticancer therapies and gut microbes. We also underlined how such interactions might impact the host response to a given therapy. We discuss the possibility of modulating the gut microbiota to increase the effectiveness/decrease the incidence of adverse events during tumor therapy. The anticipation of the future brings new evidence that gut microbiota is a target of interest to increase the efficacy of therapy.

Nutritional, Antioxidant, Antimicrobial, and Anticholinesterase Properties of Phyllanthus emblica: A Study Supported by Spectroscopic and Computational Investigations

Dietary fruits and vegetables play a vital role as food and drugs and are the main sources of antioxidant defences against degenerative diseases, such as brain dysfunctions, cardiovascular diseases, immune system deteriorations, and cancers, brought on by oxidative damage. Phyllanthus emblica is a significant herbal remedy used in conventional medicine to recover lost strength and power. In this research, the potential value of Phyllanthus emblica as a food and drug is researched. The total phenolic, total flavonoid, and total tannin contents as well as the nutritional value, vitamin C, vitamin E, and mineral contents of different organs of P. emblica were evaluated. The antioxidant and antimicrobial activities of extracts and fractions of different organs of P. emblica were determined. A total of eleven flavonoids, simple phenolic, tannin-related phenolic, and tannin molecules were isolated from a hydroalcoholic extract of the leaves and fruits. The structures were identified by spectroscopic data and comparison with the literature values as gallic acid (1), naringenin 7-O-(6″-O-galloyl)-β-D-glucopyranoside (2), 3,3'-di-O-methyl ellagic acid-4'-O-β-d-glucopyranoside (3), 1-O-galloyl glycerol (4), 1,6-di-O-galloyl-β-d-glucopyranoside (5), flavogallonic acid bislactone (6), corilagin (7), ethyl gallate (8), urolithin M5 (9), (E)-p-coumaroyl-1-O-β-d-glucopyranoside (10), and 1,2,4,6-tetra-O-galloyl-β-d-glucopyranoside (11). Among them, compounds 3 and 10 are first isolated from the plant. Molecular docking was performed to investigate the comparative interactions between positive controls (galantamine and donepezil) and selected compounds utilizing acetylcholinesterase (4EY7) as a target receptor. Results exhibited the potency of these compounds against the target receptor. In summary, P. emblica has a wealth of minerals, vitamins C and E, and polyphenolic phytochemicals that may work together to treat infectious disease, prevent and/or treat oxidative-damage-related illnesses including Alzheimer's disease.

NMR Spectroscopic Identification of Urolithin G, a Novel Trihydroxy Urolithin Produced by Human Intestinal Enterocloster Species

Urolithins are gut microbiota metabolites of ellagic acid. Here, we have identified and chemically characterized a novel urolithin produced from urolithin D (3,4,8,9-tetrahydroxy urolithin) by in vitro incubation with different human gut Enterocloster species under anaerobic conditions. Urolithin G (3,4,8-trihydroxy urolithin) was identified by 1H NMR, 13C NMR, UV, HRMS, and 2D NMR. For the identification, NMR spectra of other known urolithins were also recorded and compared. Urolithin G was present in the feces of 12% of volunteers in an overweight-obese group after consuming an ellagitannin-rich pomegranate extract. The production of urolithin G required a bacterial 9-dehydroxylase activity and was not specific to the known human urolithin metabotypes A and B. The ability to produce urolithin G could be considered an additional metabolic feature for volunteer stratification and bioactivity studies. This is the first urolithin with a catechol group in ring A while having only one hydroxyl in ring B, a unique feature not found in human and animal samples so far.

Urolithin A in Health and Diseases: Prospects for Parkinson's Disease Management

Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder characterized by a complex pathophysiology and a range of symptoms. The prevalence increases with age, putting the ageing population at risk. Disease management includes the improvement of symptoms, the comfort of the patient's life, and palliative care. As there is currently no cure, growing evidence points towards the beneficial role of polyphenols on neurodegeneration. Numerous studies indicate the health benefits of the family of urolithins, especially urolithin A (UA). UA is a bacterial metabolite produced by dietary ellagitannins and ellagic acid. An expanding body of literature explores the involvement of the compound in mitochondrial health, and its anti-inflammatory, anti-oxidant, and anti-apoptotic properties. The review organizes the existing knowledge on the role of UA in health and diseases, emphasizing neurodegenerative diseases, especially PD. We gathered data on the potential neuroprotective effect in in vivo and in vitro models. We discussed the possible mechanisms of action of the compound and related health benefits to give a broader perspective of potential applications of UA in neuroprotective strategies. Moreover, we projected the future directions of applying UA in PD management.

Simulated Gastrointestinal Digestion of Chestnut (Castanea sativa Mill.) Shell Extract Prepared by Subcritical Water Extraction: Bioaccessibility, Bioactivity, and Intestinal Permeability by In Vitro Assays

Chestnut shells (CSs) are an appealing source of bioactive molecules, and constitute a popular research topic. This study explores the effects of in vitro gastrointestinal digestion and intestinal permeability on the bioaccessibility and bioactivity of polyphenols from CS extract prepared by subcritical water extraction (SWE). The results unveiled higher phenolic concentrations retained after gastric and intestinal digestion. The bioaccessibility and antioxidant/antiradical properties were enhanced in the following order: oral < gastric ≤ intestinal digests, attaining 40% of the maximum bioaccessibility. Ellagic acid was the main polyphenol in the digested and undigested extract, while pyrogallol-protocatechuic acid derivative was only quantified in the digests. The CS extract revealed potential mild hypoglycemic (<25%) and neuroprotective (<75%) properties before and after in vitro digestion, along with upmodulating the antioxidant enzymes' activities and downregulating the lipid peroxidation. The intestinal permeation of ellagic acid achieved 22.89% after 240 min. This study highlighted the efficacy of the CS extract on the delivery of polyphenols, sustaining its promising use as nutraceutical ingredient.

Ellagic acid and its metabolites urolithins A/B ameliorate most common disease phenotypes in cellular and mouse models for lysosomal storage disorders by enhancing extracellular vesicle secretion

Niemann Pick diseases types A (NPDA) and C (NPDC) are lysosomal storage disorders (LSDs) leading to cognitive impairment, neurodegeneration, and early death. NPDA and NPDC have different genetic origins, being caused by mutations in the acid sphingomyelinase (ASM) or the cholesterol transport protein NPC1, respectively. However, they share a common pathological hallmark in the accumulation of lipids in the endolysosomal compartment. Here, we tested the hypothesis that polyphenols reduce lipid overload in NPD cells by enhancing the secretion of extracellular vesicles (ECVs). We show that among the polyphenols tested, the ellagic acid metabolites, urolithin A and B, were the safest and most efficient in increasing ECV secretion. They reduced levels of accumulating lipids and lysosomal size and permeabilization in cultured bone marrow-derived macrophages and neurons from ASMko and NPC1 mutant mice, which mimic NPDA and NPDC, respectively. Moreover, oral treatment with ellagic acid reduced lipid levels, ameliorated lysosomal alterations, and diminished microglia activation in the brain of NPD mice. These results support the therapeutic value of ECV secretion and polyphenols for NPDs, which may also help treat other LSDs characterized by intracellular lipid overload.

In Silico and In Vitro Study of Antioxidant Potential of Urolithins

In this work, quantum chemical calculations based on density functional theory (DFT) were performed to predict the antioxidant potential of four bioactive gut microbiota metabolites of the natural polyphenols ellagitannins (ETs) and ellagic acid (EA), also known as urolithins (UROs). In order to evaluate their ability to counter the effect of oxidative stress caused by reactive oxygen species (ROS), such as the hydroperoxyl radical (•OOH), different reaction mechanisms were investigated, considering water and lipid-like environments. Through our in silico results, it emerged that at physiological pH, the scavenging activity of all urolithins, except urolithin B, are higher than that of trolox and other potent antioxidants existing in nature, such as EA, α-mangostin, allicin, caffeine and melatonin. These findings were confirmed by experimental assays.

The Potential of Flavonoids and Flavonoid Metabolites in the Treatment of Neurodegenerative Pathology in Disorders of Cognitive Decline

Flavonoids are a biodiverse family of dietary compounds that have antioxidant, anti-inflammatory, antiviral, and antibacterial cell protective profiles. They have received considerable attention as potential therapeutic agents in biomedicine and have been widely used in traditional complimentary medicine for generations. Such complimentary medical herbal formulations are extremely complex mixtures of many pharmacologically active compounds that provide a therapeutic outcome through a network pharmacological effects of considerable complexity. Methods are emerging to determine the active components used in complimentary medicine and their therapeutic targets and to decipher the complexities of how network pharmacology provides such therapeutic effects. The gut microbiome has important roles to play in the generation of bioactive flavonoid metabolites retaining or exceeding the antioxidative and anti-inflammatory properties of the intact flavonoid and, in some cases, new antitumor and antineurodegenerative bioactivities. Certain food items have been identified with high prebiotic profiles suggesting that neutraceutical supplementation may be beneficially employed to preserve a healthy population of bacterial symbiont species and minimize the establishment of harmful pathogenic organisms. Gut health is an important consideration effecting the overall health and wellbeing of linked organ systems. Bioconversion of dietary flavonoid components in the gut generates therapeutic metabolites that can also be transported by the vagus nerve and systemic circulation to brain cell populations to exert a beneficial effect. This is particularly important in a number of neurological disorders (autism, bipolar disorder, AD, PD) characterized by effects on moods, resulting in depression and anxiety, impaired motor function, and long-term cognitive decline. Native flavonoids have many beneficial properties in the alleviation of inflammation in tissues, however, concerns have been raised that therapeutic levels of flavonoids may not be achieved, thus allowing them to display optimal therapeutic effects. Dietary manipulation and vagal stimulation have both yielded beneficial responses in the treatment of autism spectrum disorders, depression, and anxiety, establishing the vagal nerve as a route of communication in the gut-brain axis with established roles in disease intervention. While a number of native flavonoids are beneficial in the treatment of neurological disorders and are known to penetrate the blood–brain barrier, microbiome-generated flavonoid metabolites (e.g., protocatechuic acid, urolithins, γ-valerolactones), which retain the antioxidant and anti-inflammatory potency of the native flavonoid in addition to bioactive properties that promote mitochondrial health and cerebrovascular microcapillary function, should also be considered as potential biotherapeutic agents. Studies are warranted to experimentally examine the efficacy of flavonoid metabolites directly, as they emerge as novel therapeutic options.

The Impact of Ellagitannins and Their Metabolites through Gut Microbiome on the Gut Health and Brain Wellness within the Gut-Brain Axis

Ellagitannins (ETs) are a large group of bioactive compounds found in plant-source foods, such as pomegranates, berries, and nuts. The consumption of ETs has often been associated with positive effects on many pathologies, including cardiovascular diseases, neurodegenerative syndromes, and cancer. Although multiple biological activities (antioxidant, anti-inflammatory, chemopreventive) have been discussed for ETs, their limited bioavailability prevents reaching significant concentrations in systemic circulation. Instead, urolithins, ET gut microbiota-derived metabolites, are better absorbed and could be the bioactive molecules responsible for the antioxidant and anti-inflammatory activities or anti-tumor cell progression. In this review, we examined the dietary sources, metabolism, and bioavailability of ETs, and analyzed the last recent findings on ETs, ellagic acid, and urolithins, their intestinal and brain activities, the potential mechanisms of action, and the connection between the ET microbiota metabolism and the consequences detected on the gut-brain axis. The current in vitro, in vivo, and clinical studies indicate that ET-rich foods, individual gut microbiomes, or urolithin types could modulate signaling pathways and promote beneficial health effects. A better understanding of the role of these metabolites in disease pathogenesis may assist in the prevention or treatment of pathologies targeting the gut-brain axis.

The Interaction of Polyphenols and the Gut Microbiota in Neurodegenerative Diseases

Polyphenols are secondary metabolites of plants and play a potential role in the prevention and treatment of neurodegenerative diseases (NND) such as Alzheimer's disease (AD) and Parkinson's disease (PD) due to their unique physiological functions such as acting as antioxidants, being anti-inflammatory, being neuroprotective, and promoting intestinal health. Since dietary polyphenols exist in plant foods in the form of glycosylation or esterification or are combined with polymers, they need to undergo extensive metabolism through phase I and phase II biotransformations by various intestinal enzymes, as well as metabolism by the intestinal microbiota before they can be fully absorbed. Polyphenols improve intestinal microbiota disorders by influencing the structure and function of intestinal microbiota, inducing beneficial bacteria to produce a variety of metabolites such as short-chain fatty acids (SCFAs), promoting the secretion of hormones and neurotransmitters, and playing an important role in the prevention and treatment of NND by affecting the microbe-gut-brain axis. We review the ways in which some polyphenols can change the composition of the intestinal microbiota and their metabolites in AD or PD animal models to exert the role of slowing down the progression of NND, aiming to provide evidence for the role of polyphenols in slowing the progression of NND via the microbiota-gut-brain (MGB) axis.

Weizmannia coagulans BC2000 Plus Ellagic Acid Inhibits High-Fat-Induced Insulin Resistance by Remodeling the Gut Microbiota and Activating the Hepatic Autophagy Pathway in Mice

(1) Background: Ellagic acid (EA) acts as a product of gut microbiota transformation to prevent insulin resistance, which is limited by high-fat diet (HFD)-induced dysbiosis. The aim of this study was to investigate the synergistic effects and mechanisms of supplementation with the probiotic Weizmannia coagulans (W. coagulans) on the prevention of insulin resistance by EA; (2) Methods: C57BL/6J mice were divided into five groups (n = 10/group): low-fat-diet group, high-fat-diet group, EA intervention group, EA + W. coagulans BC77 group, and EA + W. coagulans BC2000 group; (3) Result: W. coagulans BC2000 showed a synergistic effect on EA's lowering insulin resistance index and inhibiting high-fat diet-induced endotoxemia. The combined effect of BC2000 and EA activated the autophagy pathway in the mouse liver, a urolithin-like effect. This was associated with altered β-diversity of gut microbiota and increased Eggerthellaceae, a potential EA-converting family. Ellagic acid treatment alone and the combined use of ellagic acid and W. coagulans BC77 failed to activate the hepatic autophagy pathway; (4) Conclusions: W. coagulans BC2000 can assist EA in its role of preventing insulin resistance. This study provides a basis for the development of EA-rich functional food supplemented with W. coagulans BC2000.

Exosome-Containing Extracellular Vesicles Contribute to the Transport of Resveratrol Metabolites in the Bloodstream: A Human Pharmacokinetic Study

Exosomes are extracellular vesicles (EVs) that regulate intercellular signaling by transferring small RNAs, proteins, nucleic acids, lipids, and other metabolites to local or distant organs, including the brain, by crossing the blood–brain barrier. However, the transport of (poly)phenols in human EVs has not yet been described. Therefore, we aimed here to explore (i) whether resveratrol and (or) its derived metabolites are found in the cargo of human plasma exosome-containing EVs (E-EVs), (ii) when this incorporation occurs, and (iii) whether resveratrol intake stimulates the release of E-EVs. Thus, in a pharmacokinetic study, healthy volunteers (n = 16) consumed 1 capsule (420 mg resveratrol) in the evening before attending the clinic and one more capsule on the day of the pharmacokinetics. The plasma and the isolated E-EVs were analyzed using UPLC-ESI-QTOF-MS. Of 17 metabolites in the plasma, 9 were identified in the E-EVs, but not free resveratrol. The kinetic profiles of resveratrol metabolites were similar in the plasma and the E-EVs, a higher metabolite concentration being detected in the plasma than in the E-EVs. However, the plasma/E-EVs ratio decreased in the gut microbial metabolites, suggesting their better encapsulation efficiency in E-EVs. In addition, glucuronide conjugates of resveratrol, dihydroresveratrol, and lunularin were incorporated into the E-EVs more efficiently than their corresponding sulfates despite glucuronides reaching lower plasma concentrations. Notably, more E-EVs were detected 10 h after resveratrol consumption. This exploratory study provides the first evidence that (i) resveratrol metabolites are transported by E-EVs, with a preference for glucuronide vs. sulfates, (ii) the gut microbial metabolites concentration and kinetic profiles are closely similar in E-EVs and plasma, and (iii) resveratrol intake elicits E-EVs secretion. Overall, these results open new research avenues on the possible role of E-EVs in (poly)phenol health effects.