Absorption, Distribution, Metabolism, and Excretion of the Main Olive Tree Phenols and Polyphenols: A Literature Review

Structural Optimization of Marine Natural Product Pretrichodermamide B for the Treatment of Colon Cancer by Targeting the JAK/STAT3 Signaling Pathway

Marine natural product (MNP) pretrichodermamide B (Pre B, 9) was identified as a novel STAT3 inhibitor in our previous work, while its metabolic instability hindered its further development. To address this drawback, ligand structure-based drug design was adopted leading to a series of Pre B derivatives. Among them, MNP trichodermamide B (tri B, 24) obtained by skeletal rearrangement exhibited more potent antiproliferative activity with an IC50 value of 0.12 μM against HCT116. Notably, 24 stood out with improved metabolic stability (T1/2 = 31 min) and more favorable oral bioavailability (F = 37.5%). Further studies indicated that 24 blocked JAK/STAT3 signaling in dose- and time-dependent manner. In vivo, 24 suppressed tumor growth (TGI = 65%) at a dose of 20 mg/kg in a HCT116-derived xenograft mouse model. Overall, 24 might be a promising lead compound for colon cancer and is worthy of further investigation.

Dietary supplements: clinical cholesterol-lowering efficacy and potential mechanisms of action

This review aims to analyse the efficacy of dietary supplements in reducing plasma cholesterol levels. Focusing on evidence from meta-analyses of randomised controlled clinical trials, with an emphasis on potential mechanisms of action as supported by human, animal, and cell studies. Certain dietary supplements including phytosterols, berberine, viscous soluble dietary fibres, garlic supplements, soy protein, specific probiotic strains, and certain polyphenol extracts could significantly reduce plasma total and low-density lipoprotein (LDL) cholesterol levels by 3-25% in hypercholesterolemic patients depending on the type of supplement. They tended to be more effective in reducing plasma LDL cholesterol level in hypercholesterolemic individuals than in normocholesterolemic individuals. These supplements worked by various mechanisms, such as enhancing the excretion of bile acids, inhibiting the absorption of cholesterol in the intestines, increasing the expression of hepatic LDL receptors, suppressing the activity of enzymes involved in cholesterol synthesis, and activating the adenosine monophosphate-activated protein kinase signalling pathway.

Pharmacokinetics and Metabolism Investigation of Oleocanthal

Oleocanthal is a secoiridoid found in olive oil, which lately gained great scientific interest due to its important pharmacological spectrum and biological properties. However, limited data exist on the metabolic fate of oleocanthal in vivo, a commonly underestimated aspect in natural products research. Especially, its pharmacokinetic (PK) characteristics have never been described so far. Thus, in the current study, a mouse-based protocol was designed, and oleocanthal was administered intraperitoneally in a standard dose of 5 mg/kg. In order to determine the PK parameters of oleocanthal or its metabolites, plasma samples were collected at 10 time points. Extraction and analysis protocols were developed and applied for the recovery and detection of oleocanthal in plasma, as well as the identification of its metabolites, using LC-HRMS/MS. Oleocanthal was not detected, proving the short lifetime of the compound in vivo, and 13 metabolites were identified. Among them, oleocanthalic acid and tyrosol sulfate were proposed as oleocanthal's biomarkers, in vivo. This is the first report associating oleocanthalic acid with oleocanthal administration in vivo, while its PK parameters, Tmax (T0) and Cmax (926 μg/mL), were also determined. The current study enlightens bioavailability and metabolism aspects of oleocanthal and suggests the association of specific metabolites with the biological effects attributed to oleocanthal administration. More studies are needed to give better insights into the metabolism and the mechanism of action of secoiridoids as well as to respond to identification challenges related to secoiridoid in vivo setups.

Lab-on-chip technologies for exploring the gut-immune axis in metabolic disease

The continued rise in metabolic diseases such as obesity and type 2 diabetes mellitus poses a global health burden, necessitating further research into factors implicated in the onset and progression of these diseases. Recently, the gut-immune axis, with diet as a main regulator, has been identified as a possible role player in their development. Translation of conventional 2D in vitro and animal models is however limited, while human studies are expensive and preclude individual mechanisms from being investigated. Lab-on-chip technology therefore offers an attractive new avenue to study gut-immune interactions. This review provides an overview of the influence of diet on gut-immune interactions in metabolic diseases and a critical analysis of the current state of lab-on-chip technology to study this axis. While there has been progress in the development of "immuno-competent" intestinal lab-on-chip models, with studies showing the ability of the technology to provide mechanical cues, support longer-term co-culture of microbiota and maintain in vivo-like oxygen gradients, platforms which combine all three and include intestinal and immune cells are still lacking. Further, immune cell types and inclusion of microenvironment conditions which enable in vivo-like immune cell dynamics as well as host-microbiome interactions are limited. Future model development should focus on combining these conditions to create an environment capable of hosting more complex microbiota and immune cells to allow further study into the effects of diet and related metabolites on the gut-immune ecosystem and their role in the prevention and development of metabolic diseases in humans.

Olea europaea L-derived secoiridoids: Beneficial health effects and potential therapeutic approaches

Over the years, health challenges have become increasingly complex and global and, at the beginning of the 21st century, chronic diseases, including cardiovascular, neurological, and chronic respiratory diseases, as well as cancer and diabetes, have been identified by World Health Organization as one of the biggest threats to human health. Recently, antimicrobial resistance has also emerged as a growing problem of public health for the management of infectious diseases. In this scenario, the exploration of natural products as supplementation or alternative therapeutic options is acquiring great importance, and, among them, the olive tree, Olea europaea L, specifically leaves, fruits, and oil, has been increasingly investigated for its health promoting properties. Traditionally, these properties have been largely attributed to the high concentration of monounsaturated fatty acids, although, in recent years, beneficial effects have also been associated to other components, particularly polyphenols. Among them, the most interesting group is represented by Olea europaea L secoiridoids, comprising oleuropein, oleocanthal, oleacein, and ligstroside, which display anti-inflammatory, antioxidant, cardioprotective, neuroprotective and anticancer activities. This review provides an overview of the multiple health beneficial effects, the molecular mechanisms, and the potential applications of secoiridoids from Olea europaea L.

Pharmacokinetics of Hydroxytyrosol and Its Sulfate and Glucuronide Metabolites after the Oral Administration of Table Olives to Sprague-Dawley Rats

The pharmacokinetics (PK) of hydroxytyrosol and its metabolites were characterized following oral administration to Sprague-Dawley rats of 3.85 and 7.70 g of destoned Arbequina table olives/kg. Plasma samples were analyzed using a fully validated method consisting of liquid extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Noncompartmental PK analysis of hydroxytyrosol demonstrated linear PK between doses of 2.95 and 5.85 mg hydroxytyrosol/kg. Half-life was approximately 2.5 h, while mean residence time was around 4 h. Clearance occurred by conversion to two sulfate and two glucuronide conjugates. The area under the plasma concentration-time curve (AUC) ratios of metabolites versus parent hydroxytyrosol was approximately 7-9-fold for the sulfate and below 0.25 for the glucuronide, indicating sulfation as the predominant metabolic pathway. Despite extensive metabolism, hydroxytyrosol remained in plasma for up to 8 h with AUCs of 4293 and 8919 min·nmol/L for the doses of 3.85 and 7.70 g/kg, respectively. Therefore, table olives provide a more sustained plasma profile than other foods containing hydroxytyrosol, which may enhance its health-protecting activities.

Enhancing physical and chemical stability of hygroscopic hydroxytyrosol by cocrystal formation

Hydroxytyrosol (HT) is a natural phenolic compound with potent antioxidant activity extracted from olive trees. It is generally a slightly hydrated viscous liquid at ambient conditions, and it is highly susceptible to oxygen due to the presence of catechol moiety. Although encapsulation technique provides HT in powder form, it does not improve its chemical stability. Herein, we propose an efficient solution to the high hygroscopicity and poor stability of HT. Four cocrystals were first reported, and their intermolecular interactions were analyzed in detail. After cocrystallization, the melting point is increased and the hygroscopicity is significantly decreased. HT cocrystals are thus solid at room temperature. Moreover, hydroxytyrosol cocrystals with betaine (HT-BET) and nicotinamide (HT-NIC) demonstrate superior chemical stability than pure HT, olive extract, and HT encapsulation material. Therefore, cocrystallization can be considered as a promising approach to overcome the application obstacles of HT.

Alginate-chitosan-microencapsulated tyrosols/oleuropein-rich olive mill waste extract for lipopolysaccharide-induced skin fibroblast inflammation treatment

The Ca2+ ion-driven emulsification-ionotropic gelation method produced chitosan-alginate microspheres (CAMSs) with a narrow particle size distribution (PSD). Particle size distribution and zeta potential studies, as well as spectral electron microscopy, were used to assess the microspheres' physicochemical properties and morphology. The tyrosols (hydroxytyrosol (HT), tyrosol (TY), and oleuropein (OE) were loaded into these microspheres using a polyphenol extract (PPE) from Koroneki olive mill waste (KOMW). The microencapsulation efficiency and loading capacity of microspheres for PPE were 98.8% and 3.9%, respectively. Three simulated fluids, including gastric (pH = 1.2), intestinal (pH = 6.8), and colonic (pH = 7.4), were used to examine how the pH of the releasing medium affected the ability of CAMSs to release bioactive phenols. At a severely acidic pH (1.2, SGF), PPE release is nearly halted, while at pH 6.8 (SCF), release is at its maximum. Additionally, the PPE-CAMPs have ameliorated the endogenous antioxidant content SOD, GST, GPx with significant values from 0.05 to 0.01 in the treated LPS/human skin fibroblast cells. The anti-inflammatory response was appeared through their attenuations activity for the released cytokines TNF-α, IL6, IL1β, and IL 12 with levels significantly from 0.01 to 0.001. Microencapsulation of PPE by CAMPs significantly improved its antioxidant and anti-inflammatory capabilities.

Role of Hydroxytyrosol and Oleuropein in the Prevention of Aging and Related Disorders: Focus on Neurodegeneration, Skeletal Muscle Dysfunction and Gut Microbiota

Aging is a multi-faceted process caused by the accumulation of cellular damage over time, associated with a gradual reduction of physiological activities in cells and organs. This degeneration results in a reduced ability to adapt to homeostasis perturbations and an increased incidence of illnesses such as cognitive decline, neurodegenerative and cardiovascular diseases, cancer, diabetes, and skeletal muscle pathologies. Key features of aging include a chronic low-grade inflammation state and a decrease of the autophagic process. The Mediterranean diet has been associated with longevity and ability to counteract the onset of age-related disorders. Extra virgin olive oil, a fundamental component of this diet, contains bioactive polyphenolic compounds as hydroxytyrosol (HTyr) and oleuropein (OLE), known for their antioxidant, anti-inflammatory, and neuroprotective properties. This review is focused on brain, skeletal muscle, and gut microbiota, as these systems are known to interact at several levels. After the description of the chemistry and pharmacokinetics of HTyr and OLE, we summarize studies reporting their effects in in vivo and in vitro models of neurodegenerative diseases of the central/peripheral nervous system, adult neurogenesis and depression, senescence and lifespan, and age-related skeletal muscle disorders, as well as their impact on the composition of the gut microbiota.

Metabolomic-Based Studies of the Intake of Virgin Olive Oil: A Comprehensive Review

Virgin olive oil (VOO) is a high-value product from the Mediterranean diet. Some health and nutritional benefits have been associated with its consumption, not only because of its monounsaturated-rich triacylglycerols but also due to its minor bioactive components. The search for specific metabolites related to VOO consumption may provide valuable information to identify the specific bioactive components and to understand possible molecular and metabolic mechanisms implicated in those health effects. In this regard, metabolomics, considered a key analytical tool in nutritional studies, offers a better understanding of the regulatory functions of food components on human nutrition, well-being, and health. For that reason, the aim of the present review is to summarize the available scientific evidence related to the metabolic effects of VOO or its minor bioactive compounds in human, animal, and in vitro studies using metabolomics approaches.

Characterization and Biological Activities of In Vitro Digested Olive Pomace Polyphenols Evaluated on Ex Vivo Human Immune Blood Cells

Olive pomace (OP) represents one of the main by-products of olive oil production, which still contains high quantities of health-promoting bioactive compounds. In the present study, three batches of sun-dried OP were characterized for their profile in phenolic compounds (by HPLC-DAD) and in vitro antioxidant properties (ABTS, FRAP and DPPH assays) before (methanolic extracts) and after (aqueous extracts) their simulated in vitro digestion and dialysis. Phenolic profiles, and, accordingly, the antioxidant activities, showed significant differences among the three OP batches, and most compounds showed good bioaccessibility after simulated digestion. Based on these preliminary screenings, the best OP aqueous extract (OP-W) was further characterized for its peptide composition and subdivided into seven fractions (OP-F). The most promising OP-F (characterized for its metabolome) and OP-W samples were then assessed for their potential anti-inflammatory properties in ex vivo human peripheral mononuclear cells (PBMCs) triggered or not with lipopolysaccharide (LPS). The levels of 16 pro-and anti-inflammatory cytokines were measured in PBMC culture media by multiplex ELISA assay, whereas the gene expressions of interleukin-6 (IL-6), IL-10 and TNF-α were measured by real time RT-qPCR. Interestingly, OP-W and PO-F samples had a similar effect in reducing the expressions of IL-6 and TNF-α, but only OP-W was able to reduce the release of these inflammatory mediators, suggesting that the anti-inflammatory activity of OP-W is different from that of OP-F.

A Network Pharmacology Method Combined with Molecular Docking Verification to Explore the Therapeutic Mechanisms Underlying Simiao Pill Herbal Medicine against Hyperuricemia

Objective

Hyperuricemia (HUA) is a common metabolic disease caused by disordered purine metabolism. We aim to reveal the mechanisms underlying the anti-HUA function of Simiao pill and provide therapeutic targets.

Methods

Simiao pill-related targets were obtained using Herbal Ingredients' Targets (HIT), Traditional Chinese Medicine Systems Pharmacology (TCMSP), and Traditional Chinese Medicine Integrated Database (TCMID). HUA-associated targets were retrieved from GeneCards, DisGeNET, and Therapeutic Targets Database (TTD). Protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, ggraph and igraph R packages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed using ClusterProfiler. The top 10 core targets were identified through cytoHubba. Molecular docking was conducted using PyMOL and AutoDock high-performance liquid chromatograph (HPLC) analysis was performed to identify effective compounds of Simiao pill.

Results

Simiao pill-HUA target network contained 80 targets. The key targets were mainly involved in inflammatory responses. Insulin (INS), tumor necrosis factor (TNF), interleukin-6 (IL6), interleukin 1 beta (IL1B), vascular endothelial growth factor A (VEGFA), leptin (LEP), signal transducer and activator of transcription 3 (STAT3), C-C motif chemokine ligand 2 (CCL2), interleukin-10 (IL10), and toll like receptor 4 (TLR4) were the top 10 targets in the PPI network. GO analysis demonstrated the main implication of the targets in molecular responses, production, and metabolism. KEGG analysis revealed that Simiao pill might mitigate HUA through advanced glycation end-product- (AGE-) receptor for AGE- (RAGE-) and hypoxia-inducible factor-1- (HIF-1-) associated pathways. IL1B, IL6, IL10, TLR4, and TNF were finally determined as the promising targets of Simiao pill treating HUA. Through molecular docking and HPLC analysis, luteolin, quercetin, rutaecarpine, baicalin, and atractylenolide I were the main active compounds.

Conclusions

Simiao pill can mitigate HUA by restraining inflammation, mediating AGE-RAGE- and HIF-1-related pathways, and targeting IL1B, IL6, IL10, TLR4, and TNF.

Interfacial Imide Polymerization of Functionalized Filled Microcapsule Templates by the Pickering Emulsion Method for the Rapid Removal of 3,4,5-Trichlorophenol from Wastewater

In this work, an olive oil-filled composite capsule (C-O/W) adsorbent was prepared for the adsorption of 3,4,5-trichlorophenol (3,4,5-TCP) by the emulsion templating method. Using methylene diisocyanate (HDI) and 1,6-hexanediamine (HMDA) as functional monomers, olive oil was encapsulated in a shell layer composed of graphene oxide and a polymer by interfacial imine polymerization. The contaminant target was efficiently removed by the hydrophobic interaction between olive oil and chlorophenols. The removal of 3,4,5-TCP was remarkable, with an encapsulation rate of 85%. The unique microcapsule structure further enhanced the kinetic performance, which reached 92% of the maximum value within 40 min. The adsorption of different chlorophenols was investigated using 2-chlorophenol (2-CP), 2,6-dichlorophenol (2,6-DCP), and 3,4,5-TCP. The adsorption of 3,4,5-TCP by the C-O/W microcapsules was found to be much higher than that of other chlorophenols. When analyzing a real sample, the content of 3,4,5-TCP was significantly reduced after adsorption by the C-O/W microcapsules, demonstrating that the C-O/W microcapsules were also capable of removing 3,4,5-TCP from a complex environment. This simple and inexpensive preparation strategy provides a new method for the synthesis of functionalized C-O/W microcapsule adsorbents and an effective adsorbent of 3,4,5-TCP.

Metabolism and Bioavailability of Olive Bioactive Constituents Based on In Vitro, In Vivo and Human Studies

Consumption of olive products has been established as a health-promoting dietary pattern due to their high content in compounds with eminent pharmacological properties and well-described bioactivities. However, their metabolism has not yet been fully described. The present critical review aimed to gather all scientific data of the past two decades regarding the absorption and metabolism of the foremost olive compounds, specifically of the phenylalcohols hydroxytyrosol (HTyr) and tyrosol (Tyr) and the secoiridoids oleacein (Olea), oleocanthal (Oleo) and oleuropein (Oleu). A meticulous record of the in vitro assays and in vivo (animals and humans) studies of the characteristic olive compounds was cited, and a critical discussion on their bioavailability and metabolism was performed taking into account data from their gut microbial metabolism. The existing critical review summarizes the existing knowledge regarding the bioavailability and metabolism of olive-characteristic phenylalchohols and secoiridoids and spotlights the lack of data for specific chemical groups and compounds. Critical observations and conclusions were derived from correlating structure with bioavailability data, while results from in vitro, animal and human studies were compared and discussed, giving significant insight to the future design of research approaches for the total bioavailability and metabolism exploration thereof.

A biochemical perspective on the fate of virgin olive oil phenolic compounds in vivo

The chemistry of the phenolic compounds found in virgin olive oil (VOO) is very complex due, not only to the different classes of polyphenols that can be found in it, but, above all, due to the existence of a very specific phenol class found only in oleaceae plants: the secoiridoids. Searching in the Scopus data base the keywords flavonoid, phenolic acid, lignin and secoiridoid, we can find a number of 148174, 79435, 11326 and 1392 research articles respectively, showing how little is devote to the latter class of compounds. Moreover, in contrast with other classes, that include only phenolic compounds, secoiridoids may include phenolic and non-phenolic compounds, being the articles concerning phenolic secoiridoids much less than the half of the abovementioned articles. Therefore, it is important to clarify the structures of these compounds and their chemistry, as this knowledge will help understand their bioactivity and metabolism studies, usually performed by researchers with a more health science's related background. In this review, all the structures found in many research articles concerning VOO phenolic compounds chemistry and metabolism was gathered, with a special attention devoted to the secoiridoids, the main phenolic compound class found in olives, VOO and olive leaf.

A Comprehensive Review on the Anti-Cancer Effects of Oleuropein

In Mediterranean cuisine and culture, olive oil and olive fruits play a significant role. Many people believe that those who consume olive oil and its fruit live longer and have a decreased risk of illness. Olive leaves were used to treat a range of diseases in ancient times, including malaria fever and lower earaches. Although it was not understood at the time what key components were responsible for these effects because they had not yet been discovered, Oleuropein is now recognized as one of the primary elements in immature olive fruits and leaves. Later research was carried out to determine the effects of this molecule, and it was determined that it functions as an antioxidant. Oleuropein consumption has aided in cancer treatment over the years, and this was assumed to be owing to its antioxidant properties. Oleuropein’s effects on cancer, however, go beyond that; it is now known that Oleuropein functions as both an anti-proliferative and an apoptotic promoter in many cancer cells. The kinetics and dosages of Oleuropein and the mechanisms behind its involvement and effects in cancer are explored in this review. Finally, the effects of Oleuropein in combination with anticancer medicines are investigated.

Oleuropein Counteracts Both the Proliferation and Migration of Intra- and Extragonadal Seminoma Cells

Recent and growing literature has reported that oleuropein (OLE), the main polyphenol in olive leaf extract, inhibits tumor cell proliferation and reduces the invasiveness properties of cancer cells; therefore, OLE may play a significant role in the development of new drugs for cancer treatment. These antineoplastic properties have been reported in many experimental cancer models, but the effect of OLE on seminoma cells is yet to be evaluated. In the present study, we demonstrate, for the first time, that OLE reduces cell viability in both intra- and extragonadal TCAM-2 and SEM-1 seminoma cells, respectively, in a dose-dependent manner. As shown by Western-blot analysis, OLE exposure reduced cyclin-D1 expression and upregulated p21^Cip/WAF1, concomitantly affecting the upstream pathway of NF-κB, leading to the reduction of its nuclear content, thereby suggesting that OLE could modulate cell-cycle regulators by inhibiting NF-κB. Moreover, Annexin V staining revealed that OLE induced apoptosis in cancer cells and upregulated the pro-apoptotic factor BAX. Through wound-healing scratch and transmigration assays, we also demonstrated that OLE significantly reduced the migration and motility of TCAM-2 and SEM-1 cells, and downregulated the expression of TGFβ-1, which is known to be the main pro-fibrotic factor involved in the acquisition of the migratory and invasive properties of cancer cells. Collectively, our results indicate that OLE reduces seminoma cell proliferation, promotes apoptosis, and counteracts cell migration and motility. Further studies are needed to explore the molecular mechanisms underlying these observed effects.

Host-guest inclusion complexes of hydroxytyrosol with cyclodextrins: Development of a potential functional ingredient for food application

Hydroxytyrosol (HT), a potent phenolic phytochemical, exerts positive health effects due to its antioxidant properties. However, it is highly reactive to oxygen, light, and heat and presents high instability. Alpha- and beta-cyclodextrin (α-CD, β-CD) have structures that allow them to encapsulate a variety of hydrophobic molecules. The aim of this study was to examine the outcomes of the inclusion of HT into α-CD and β-CD. Aqueous solutions of HT and either α-CD or β-CD were prepared and freeze-drying was applied for the encapsulation, in 1:1 and 2:1 molar ratios. The produced solid complexes were studied and characterized using NMR spectroscopy, differential scanning calorimetry (DSC) and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). Encapsulation efficiency (EE%), stability, and in vitro release of the encapsulated complexes under simulated digestion conditions were also evaluated. In both DSC thermograms and FTIR spectra of the inclusion complexes, absence of the characteristic peaks of HT and shifts of the CDs peaks were observed, showing an interaction between the molecules. NMR suggested a stronger complex formed between β-CD and HT. The EE% of β-CD/HT (1:1 and 2:1) complexes and α-CD/HT (1:1) complex was found to be higher (83%, 76%, 78%, respectively), compared to α-CD/HT (2:1) (51%). Data obtained support the encapsulation of HT in both CDs, revealing a potential interaction between them and an improvement in HT's thermal stability. Regarding the in vitro release study, both CD complexes had similar behavior and a controlled release of HT in the intestinal site was observed. PRACTICAL APPLICATION: The encapsulation of hydroxytyrosol in cyclodextrins resulted in white amorphous food-grade powders with no aroma and taste. Incorporation of these powders in foods could lead to an increase in their antioxidant content and offer an additional nutritional value.

Type does matter. Use VIRGIN olive oil as your preferred fat to reduce your risk of breast cancer: case-control EpiGEICAM study

The Epi-GEICAM study comprises 1017 invasive BC cases matched with controls of similar age (49 ± 9 years) and residence. Diet and OO consumption were collected through a validated food frequency questionnaire. 75% of women referred OO, common (refined) or virgin, as the main fat source. Using conditional logistic regression models, we compared different scenarios of type and frequency of OO consumption, using as reference those women not always using OO for the three culinary practices (seasoning, cooking, and frying) and adding <2 tablespoons (tbsps.) per day during the meal to bread, salad, or dishes. A substantial inverse association was observed in those women always using VOO for the three culinary practices and consuming ≥2 tbsps. of OO per day during meals (adjusted OR, 0.72; 95% CI: 0.51, 1.03; P = 0.07). Potential benefits from OO consumption, at least as regards the protection provided for BC, could be mostly conferred with VOO, and when its consumption is high.

Construction and characterization of Juglans regia L. polyphenols nanoparticles based on bovine serum albumin and Hohenbuehelia serotina polysaccharides, and their gastrointestinal digestion and colonic fermentation in vitro

Herein, we report the construction and characterization of nanoparticles based on bovine serum albumin and Hohenbuehelia serotina polysaccharides for the delivery of polyphenols isolated from the shells of Juglans regia L. (BSA-JRP-HSP NPs). We also systematically investigated their gastrointestinal digestion and colonic fermentation characteristics in vitro. BSA-JRP-HSP NPs, with amorphous properties and regular spherical morphological features, have a high encapsulation efficiency of 88.47 ± 0.04%, average particle size of 285.7 ± 3.1 nm, and zeta potential of -12.20 ± 0.61 mV, and they exhibit excellent photothermal stabilities and strong mucin adhesion capacity. Through measurements of gastrointestinal digestion and colonic fermentation in vitro, the results suggest that BSA-JRP-HSP NPs presented well-sustained release characteristics for preventing the biodegradation of JRP during gastrointestinal digestion. After gastrointestinal digestion, BSA-JRP-HSP NPs could modulate the composition and structure of gut microbiota, promoting the growth of beneficial bacterial (e.g. Prevotella, Dialister, Akkermansia, etc.) and inhibiting the growth of pathogenic bacteria (e.g. Bacteroides, Phascolarctobacterium, Lachnospiracea incertae sedis, etc.). The production of short-chain fatty acids (SCFAs) including acetic acid, propionic acid, and butyric acid was remarkably enhanced by treatment with BSA-JRP-HSP NPs. This study has proved that BSA-JRP-HSP NPs can serve as a novel candidate for improving the bioavailability of JRP.

Main drivers of (poly)phenol effects on human health: metabolite production and/or gut microbiota-associated metabotypes?

Despite the high human interindividual variability in response to (poly)phenol consumption, the cause-and-effect relationship between some dietary (poly)phenols (flavanols and olive oil phenolics) and health effects (endothelial function and prevention of LDL oxidation, respectively) has been well established. Most of the variables affecting this interindividual variability have been identified (food matrix, gut microbiota, single-nucleotide-polymorphisms, etc.). However, the final drivers for the health effects of (poly)phenol consumption have not been fully identified. At least partially, these drivers could be (i) the (poly)phenols ingested that exert their effect in the gastrointestinal tract, (ii) the bioavailable metabolites that exert their effects systemically and/or (iii) the gut microbial ecology associated with (poly)phenol metabolism (i.e., gut microbiota-associated metabotypes). However, statistical associations between health effects and the occurrence of circulating and/or excreted metabolites, as well as cross-sectional studies that correlate gut microbial ecologies and health, do not prove a causal role unequivocally. We provide a critical overview and perspective on the possible main drivers of the effects of (poly)phenols on human health and suggest possible actions to identify the putative actors responsible for the effects.

Comparison between In Vitro Chemical and Ex Vivo Biological Assays to Evaluate Antioxidant Capacity of Botanical Extracts

The anti-oxidative activity of plant-derived extracts is well-known and confers health-promoting effects on functional foods and food supplements. Aim of this work is to evaluate the capability of two different assays to predict the real biological antioxidant efficiency. At this purpose, extracts from five different plant-derived matrices and commercial purified phytochemicals were analyzed for their anti-oxidative properties by using well-standardized in vitro chemical method (TEAC) and an ex vivo biological assay. The biological assay, a cellular membrane system obtained from erythrocytes of healthy volunteers, is based on the capability of phytochemicals treatment to prevent membrane lipid peroxidation under oxidative stress by UV-B radiation. Plant extracts naturally rich in phenols with different structure and purified phytochemicals showed different in vitro and ex vivo antioxidant capacities. A high correlation between phenolic contents of the plant-derived extracts and their ability to prevent oxidative injuries in a biological system was found, thus underlying the relevance of this class of metabolites in preventing oxidative stress. On the other hand, a low correlation between the antioxidant capacities was shown between in vitro and ex vivo antioxidant assay. Moreover, data presented in this work show how food complex matrices are more effective in preventing oxidative damages at biological level than pure phytochemicals, even if for these latter, the antioxidant activity was generally higher than that observed for food complex matrices.