New red-fleshed apple cultivars: a comprehensive review of processing effects, (poly)phenol bioavailability and biological effects

Red-fleshed apple cultivars with an enhanced content of anthocyanins have recently attracted the interest of apple producers and consumers due to their attractive color and promising added health benefits. In this paper, we provide the first comprehensive overview of new hybrid red-fleshed apples, mainly focusing on their (poly)phenolic composition, the effect of processing, the (poly)phenolic bioavailability and the biological effects. Evidence so far from in vitro and in vivo studies supports their added beneficial effects compared to common apples on health outcomes such as cancer, cardiovascular disease, inflammation and immune function, which are mainly related to their specific (poly)phenol composition.

Red-Fleshed Apples Rich in Anthocyanins and White-Fleshed Apples Modulate the Aorta and Heart Proteome in Hypercholesterolaemic Rats: The AppleCOR Study

The impact of a red-fleshed apple (RFA) rich in anthocyanins (ACNs), a white-fleshed apple (WFA) without ACNs, and an extract infusion from Aronia fruit (AI) equivalent in dose of cyanidin-3-O-galactoside (main ACN) as RFA was determined by the proteome profile of aorta and heart as key cardiovascular tissues. Hypercholesterolaemic Wistar rats were separated into six groups (n = 6/group; three males and three females) and the proteomic profiles were analyzed using nanoliquid chromatography coupled to mass spectrometry. No adverse events were reported and all products were well tolerated. RFA downregulated C1QB and CFP in aorta and CRP in heart. WFA downregulated C1QB and CFP in aorta and C9 and C3 in aorta and heart, among other proteins. AI downregulated PRKACA, IQGAP1, and HSP90AB1 related to cellular signaling. Thus, both apples showed an anti-inflammatory effect through the complement system, while RFA reduced CRP. Regardless of the ACN content, an apple matrix effect was observed that involved different bioactive components, and inflammatory proteins were reduced.

Serum lysophospholipidome of dietary origin as a suitable susceptibility/risk biomarker of human hypercholesterolemia: A cross-sectional study

BACKGROUND & AIMS

Whether bioactive lysophospholipids (lyso-PLs) and trimethylamine-N-oxide (TMAO) serve as non-invasive biomarkers in early human hypercholesterolemia (HC) is unknown. This study aimed to assess whether serum lyso-PLs and plasma TMAO may be suitable susceptibility/risk biomarkers of HC in humans. Secondarily, we aimed to evaluate the relationships between targeted metabolites, diet composition and circulating liver transaminases, and verify these results in hamsters.

METHODS

A targeted metabolomics and lipidomics approach determined plasma TMAO and serum lysophosphatidylcholines (lyso-PCs) and lysophosphatidylethanolamines (lyso-PEs) in low (L-LDL-c) and moderate to high (MH-LDL-c) LDL-cholesterol subjects. Additionally, the relationships between targeted metabolites, liver transaminases and diet, particularly fatty acid intake, were tested. In parallel, plasma and liver lyso-PL profiles were studied in 16 hamsters fed a moderate high-fat (HFD) or low-fat (LFD) diet for 30 days.

RESULTS

Predictive models identified lyso-PC15:0 and lyso-PE18:2 as the most discriminant lyso-PLs among groups. In MH-LDL-c (n = 48), LDL-cholesterol and saturated FAs were positively associated with lyso-PC15:0, whereas in L-LDL-c (n = 70), LDL-cholesterol and polyunsaturated fatty acids (PUFAs) were negatively and positively related to lyso-PE18:2, respectively. Interestingly, in MH-LDL-c, the lower lyso-PE 18:2 concentrations were indicative of higher LDL-cholesterol levels. Intrahepatic accumulation of lyso-PLs-containing essential n-6 PUFAs, including lyso-PE18:2, were higher in HFD-fed hamsters than LFD-fed hamsters.

CONCLUSIONS

Overall, results revealed a possible hepatic adaptive mechanism to counteract diet-induced steatosis in animal and hypercholesterolemia progression in humans. In particular, low serum lyso-PE18:2 suggests a suitable susceptibility/risk biomarker of HC in humans.

The health benefits of anthocyanins: an umbrella review of systematic reviews and meta-analyses of observational studies and controlled clinical trials

Anthocyanins (ACNs) are phenolic compounds present in foods and have undefined health benefits. The present umbrella review aimed to analyze the effects of ACNs on multiple aspects of human health (from systematic reviews and meta-analyses [SRMs] of randomized controlled trials [RCTs]), and the associations of ACNs with the risk of various diseases (from SRMs of observational studies [OSs]). Following the PRISMA methodology, the PubMed, SCOPUS, and Cochrane databases were searched up to November 1, 2020 for OS-SRMs and RCT-SRMs that examined the effects of ACNs on health. The risk of bias of RCT-SRMs was assessed using the AMSTAR 2, and that of OS-SRMs was assessed using the Joanna Briggs Institute methodology. Based on 5 OS-SRMs (57 studies and 2 134 336 participants), ACNs of various sources were significantly associated with a reduction in the risks of hypertension and type 2 diabetes mellitus. According to 8 RCT-SRMs (139 interventions and >4984 participants), ACNs improved plasmatic lipids, glucose metabolism, and endothelial function, without affecting blood pressure. No associations between ACNs and breast or gastric cancer risks were found. ACN intake opens new pathways for the management of glucose metabolism, the plasmatic lipid profile, and the improvement of endothelial function in humans.

Variation in the Methylation of Caffeoylquinic Acids and Urinary Excretion of 3'-methoxycinnamic acid-4'-Sulfate After Apple Consumption by Volunteers

INTRODUCTION

It has been reported that the phenolic metabolite 3'-methoxycinnamic acid-4'-sulfate generated from 5-O-caffeoylquinic acid may have potential benefits in human health. However, the variation in 3'- and 4'-methylation of 3',4'-dihydroxycinnamic acid and its impact on the yield of this sulfate metabolite is unclear and has been poorly studied.

METHODS AND RESULTS

To address this aim, the excreted 3'-methoxy and 4'-methoxy metabolites in urine samples (24-h) are determined in 14 volunteers after an acute intake of 80 g of red-fleshed apple (RFA) or white-fleshed apple (WFA). These methoxy metabolites are also determined in the same volunteers in a second acute intake after a 6-week sustained consumption of the same products.

CONCLUSION

Seven 3'-methoxy and seven 4'-methoxy metabolites are determined, i.e., the free cinnamic and corresponding phenylpropanoic acid, plus their sulfate, glucuronide, and glycine conjugates. In only six volunteers, five females and one male, is 4'-methylation preferred over 3'-methylation, but it is observed that an individual's 3'- : 4'-methylation ratio can change over time, and that the yield of 3'-methoxycinnamic acid-4'-sulfate is extremely variable, ranging from undetectable to 71% of the total C6 -C3 metabolites excreted, and any benefit accruing from this metabolite will not necessarily be available to all consumers.

Virgin Olive Oil Phenolic Compounds Modulate the HDL Lipidome in Hypercholesterolaemic Subjects: A Lipidomic Analysis of the VOHF Study

Scope

The lipidomic analysis of high‐density lipoprotein (HDL) could be useful to identify new biomarkers of HDL function.

Methods and results

A randomized, controlled, double‐blind, crossover trial (33 hypercholesterolaemic subjects) is performed with a control virgin olive oil (VOO), VOO enriched with its own phenolic compounds (FVOO), or VOO enriched with additional phenolic compounds from thyme (FVOOT) for 3 weeks. HDL lipidomic analyses are performed using the Lipidyzer platform. VOO and FVOO intake increase monounsaturated‐fatty acids (FAs) and decrease saturated and polyunsaturated FAs in triacylglyceride (TAG) species, among others species. In contrast, FVOOT intake does not induce these FAs changes. The decrease in TAG52:3(FA16:0) after VOO intake and the decrease in TAG52:5(FA18:2) after FVOO intake are inversely associated with changes in HDL resistance to oxidation. After FVOO intake, the decrease in TAG54:6(FA18:2) in HDL is inversely associated with changes in HDL cholesterol efflux capacity.

Conclusion

VOO and FVOO consumption has an impact on the HDL lipidome, in particular TAG species. Although TAGs are minor components of HDL mass, the observed changes in TAG modulated HDL functionality towards a cardioprotective mode. The assessment of the HDL lipidome is a valuable approach to identify and characterize new biomarkers of HDL function.

Phosphoproteomic Analysis and Protein-Protein Interaction of Rat Aorta GJA1 and Rat Heart FKBP1A after Secoiridoid Consumption from Virgin Olive Oil: A Functional Proteomic Approach

Protein functional interactions could explain the biological response of secoiridoids (SECs), main phenolic compounds in virgin olive oil (VOO). The aim was to assess protein-protein interactions (PPIs) of the aorta gap junction alpha-1 (GJA1) and the heart peptidyl-prolyl cis-trans isomerase (FKBP1A), plus the phosphorylated heart proteome, to describe new molecular pathways in the cardiovascular system in rats using nanoliquid chromatography coupled with mass spectrometry. PPIs modified by SECs and associated with GJA1 in aorta rat tissue were calpain, TUBA1A, and HSPB1. Those associated with FKBP1A in rat heart tissue included SUCLG1, HSPE1, and TNNI3. In the heart, SECs modulated the phosphoproteome through the main canonical pathways PI3K/mTOR signaling (AKT1S1 and GAB2) and gap junction signaling (GAB2 and GJA1). PPIs associated with GJA1 and with FKBP1A, the phosphorylation of GAB2, and the dephosphorylation of GJA1 and AKT1S1 in rat tissues are promising protein targets promoting cardiovascular protection to explain the health benefits of VOO.

Thermal and non-thermal processing of red-fleshed apple: how are (poly)phenol composition and bioavailability affected?

The present study evaluated the impact of different thermal (infrared-drying, hot air-drying and purée pasteurization) and non-thermal (freeze-drying) processing technologies on red-fleshed apple (poly)phenolic compounds. We further investigated the processing effect on the (poly)phenol bioavailability in a crossover postprandial study where three subjects consumed three apple products (freeze-dried snack, hot air-dried snack and pasteurized purée). (Poly)phenolic compounds present in the apple products and their biological metabolites in urine were analyzed using liquid chromatography coupled to mass spectrometry (UPLC-MS/MS). When comparing different processes, infrared-drying caused important losses in most of the apple (poly)phenolics, while hot air-drying and purée pasteurization maintained approximately 83% and 65% of total (poly)phenols compared with the freeze-dried snack, respectively. Anthocyanins in particular were degraded to a higher extent, and hot air-dried apple and pasteurized purée maintained respectively 26% and 9% compared with freeze-dried apple snack. The acute intake showed that pasteurized purée exhibited the highest (poly)phenol bioavailability, followed by hot air-drying and freeze-dried snack, highlighting the impact of processing on (poly)phenols absorption. In conclusion, for obtaining affordable new red-fleshed apple products with enhanced (poly)phenol bioavailability, purée pasteurization and hot air-drying represent viable techniques. However, to obtain a red-fleshed apple snack with high anthocyanin content, freeze-drying is the technique that best preserves them.

Application of Dried Blood Spot Cards combined with liquid chromatography-tandem mass spectrometry to determine eight fat-soluble micronutrients in human blood

The analysis of the fat-soluble vitamins A and E and lipid micronutrients in blood, such as carotenoids, is an important parameter to monitor the micronutrient status in humans. Although the potential of dried blood spot (DBS) cards, the use of this technique for blood sampling and subsequent analysis of these fat-soluble micronutrients has been poorly or not studied. An analytical method based on DBS cards (FTA® DMPK-A) combined with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been developed and validated for the determination of carotenoids (lutein, zeaxanthin, β-cryptoxanthin and β-carotene), tocopherols (α-tocopherol, γ-tocopherol and δ-tocopherol) and all-trans-retinol in human blood. Under optimum DBS card extraction conditions, the extraction recoveries of the studied compounds were higher than 72%, the sample matrix effect lower than 17%, and the detection limits at hundred nM concentration levels. The developed method was applied to the analysis of human blood, and the concentration ranges obtained fell within the expected ranges previously reported in healthy adults. Moreover, the influence of hematocrit effect was investigated in a range of 25-55% in order to compare the obtained results to those reported in the literature for the analysis of plasma samples. This method represents an improvement over current techniques reported in the literature due to the use of a non-invasive blood collection method, and moreover, this methodology was for the first time 1) validated for the analysis of all-trans-retinol, tocopherols and carotenoids, and 2) applied for the determination of tocopherols in human blood samples.

Phenol-Enriched Virgin Olive Oil Promotes Macrophage-Specific Reverse Cholesterol Transport In Vivo

The intake of olive oil (OO) enriched with phenolic compounds (PCs) promotes ex vivo HDL-mediated macrophage cholesterol efflux in humans. We aimed to determine the effects of PC-enriched virgin OO on reverse cholesterol transport (RevCT) from macrophages to feces in vivo. Female C57BL/6 mice were given intragastric doses of refined OO (ROO) and a functional unrefined virgin OO enriched with its own PC (FVOO) for 14 days. Our experiments included two independent groups of mice that received intragastric doses of the phenolic extract (PE) used to prepare the FVOO and the vehicle solution (saline), as control, for 14 days. FVOO intake led to a significant increase in serum HDL cholesterol and its ability to induce macrophage cholesterol efflux in vitro when compared with ROO group. This was concomitant with the enhanced macrophage-derived [³H]cholesterol transport to feces in vivo. PE intake per se also increased HDL cholesterol levels and significantly promoted in vivo macrophage-to-feces RevCT rate when compared with saline group. PE upregulated the expression of the main macrophage transporter involved in macrophage cholesterol efflux, the ATP binding cassettea1. Our data provide direct evidence of the crucial role of OO PCs in the induction of macrophage-specific RevCT in vivo.

Impact of Phenol-Enriched Virgin Olive Oils on the Postprandial Levels of Circulating microRNAs Related to Cardiovascular Disease

SCOPE

We investigate the postprandial modulation of cardiovascular-related microRNAs elicited by extra virgin olive oil (EVOOs) containing different levels of their own polyphenols.

METHODS AND RESULTS

It is randomized, postprandial, parallel, double-blind study. Twelve healthy participants consumed 30 mL of EVOO containing low (L-EVOO; 250 mg total phenols kg-1 of oil), medium (M-EVOO; 500 mg total phenols kg-1 of oil), and high (H-EVOO; 750 mg total phenols kg-1 of oil) enriched EVOOs. Postprandial plasma microRNAs levels are analyzed by real-time quantitative PCR. The results show that L-EVOO intake is associated with decreased let-7e-5p and miR-328a-3p levels and increased miR-17-5p and miR-20a-5p, concentrations. M-EVOO decreases plasma let-7e-5p and increases miR-17-5p, miR-20a-5p, and miR-192-5p levels. Finally, H-EVOO decreases let-7e-5p, miR-10a-5p, miR-21-5p, and miR-26b-5p levels.

CONCLUSION

During the postprandial state, the levels of let-7e-5p decrease with EVOO regardless of polyphenol content suggesting a general response to the fatty acid composition of EVOO or/and the presence of at least 250 mg polyphenol kg-1 olive oil. Moreover, the miR-17-92 cluster increases by low and medium polyphenol content suggesting a role in fatty acid metabolism and nutrient sensing. Thus, postprandial modulation of circulating microRNAs levels could be a potential mechanism for the cardiovascular benefits associated with EVOO intake.

Effects of hesperidin in orange juice on blood and pulse pressures in mildly hypertensive individuals: a randomized controlled trial (Citrus study)

Purpose

To assess the sustained and acute effects, as well as the influence of sustained consumption on the acute effects, of orange juice (OJ) with a natural hesperidin content and hesperidin-enriched OJ (EOJ) on blood (BP) and pulse (PP) pressures in pre- and stage-1 hypertensive individuals.

Methods

In a randomized, parallel, double-blind, placebo-controlled trial, participants (n = 159) received 500 mL/day of control drink, OJ, or EOJ for 12 weeks. Two dose–response studies were performed at baseline and after 12 weeks.

Results

A single EOJ dose (500 mL) reduced systolic BP (SBP) and PP, with greater changes after sustained treatment where a decrease in diastolic BP (DBP) also occurred (P < 0.05). SBP and PP decreased in a dose-dependent manner relative to the hesperidin content of the beverages throughout the 12 weeks (P < 0.05). OJ and EOJ decreased homocysteine levels at 12 weeks versus the control drink (P < 0.05). After 12 weeks of EOJ consumption, four genes related to hypertension (PTX3, NLRP3, NPSR1 and NAMPT) were differentially expressed in peripheral blood mononuclear cells (P < 0.05).

Conclusion

Hesperidin in OJ reduces SBP and PP after sustained consumption, and after a single dose, the chronic consumption of EOJ enhances its postprandial effect. Decreases in systemic and transcriptomic biomarkers were concomitant with BP and PP changes. EOJ could be a useful co-adjuvant tool for BP and PP management in pre- and stage-1 hypertensive individuals.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02279-0) contains supplementary material, which is available to authorized users.

A Functional Virgin Olive Oil Enriched with Olive Oil and Thyme Phenolic Compounds Improves the Expression of Cholesterol Efflux-Related Genes: A Randomized, Crossover, Controlled Trial

The consumption of antioxidant-rich foods such as virgin olive oil (VOO) promotes high-density lipoprotein (HDL) anti-atherogenic capacities. Intake of functional VOOs (enriched with olive/thyme phenolic compounds (PCs)) also improves HDL functions, but the gene expression changes behind these benefits are not fully understood. Our aim was to determine whether these functional VOOs could enhance the expression of cholesterol efflux-related genes. In a randomized, double-blind, crossover, controlled trial, 22 hypercholesterolemic subjects ingested for three weeks 25 mL/day of: (1) a functional VOO enriched with olive oil PCs (500 mg/kg); (2) a functional VOO enriched with olive oil (250 mg/kg) and thyme PCs (250 mg/kg; FVOOT), and; (3) a natural VOO (olive oil PCs: 80 mg/kg, control intervention). We assessed whether these interventions improved the expression of cholesterol efflux-related genes in peripheral blood mononuclear cells by quantitative reverse-transcription polymerase chain reactions. The FVOOT intervention upregulated the expression of CYP27A1 (p = 0.041 and p = 0.053, versus baseline and the control intervention, respectively), CAV1 (p = 0.070, versus the control intervention), and LXRβ, RXRα, and PPARβ/δ (p = 0.005, p = 0.005, and p = 0.038, respectively, relative to the baseline). The consumption of a functional VOO enriched with olive oil and thyme PCs enhanced the expression of key cholesterol efflux regulators, such as CYP27A1 and nuclear receptor-related genes.

Identification and validation of common molecular targets of hydroxytyrosol

Hydroxytyrosol (HT) is involved in healthful activities and is beneficial to lipid metabolism. Many investigations focused on finding tissue-specific targets of HT through the use of different omics approaches such as transcriptomics and proteomics. However, it is not clear which (if any) of the potential molecular targets of HT reported in different studies are concurrently affected in various tissues. Following the bioinformatic analyses of publicly available data from a selection of in vivo studies involving HT-supplementation, we selected differentially expressed lipid metabolism-related genes and proteins common to more than one study, for validation in rodent liver samples from the entire selection. Four miRNAs (miR-802-5p, miR-423-3p, miR-30a-5p, and miR-146b-5p) responded to HT supplementation. Of note, miR-802-5p was commonly regulated in the liver and intestine. Our premise was that, in an organ crucial for lipid metabolism such as the liver, consistent modulation should be found for a specific target of HT even if different doses and duration of HT supplementation were used in vivo. Even though our results show inconsistency regarding differentially expressed lipid metabolism-related genes and proteins across studies, we found Fgf21 and Rora as potential novel targets of HT. Omics approaches should be fine-tuned to better exploit the available databases.

Faecal bacterial and short-chain fatty acids signature in hypercholesterolemia

Gut microbiota has been suggested to affect lipid metabolism. The objective of this study was to characterize the faecal microbiota signature and both short chain fatty acids (SCFAs) and bile acids (BA) profile of hypercholesterolemic subjects. Microbiota composition, SCFAs, BA and blood lipid profile from male volunteers with hypercholesterolemia (HC) and normocholesterolemia (NC) were determined by 16S rDNA sequencing, HPLC, GC and NMR, respectively. HC subjects were characterized by having lower relative abundance of Anaeroplasma (0.002% vs 0.219%, p-value = 0.026) and Haemophilus (0.041% vs 0.078%, p-value = 0.049), and higher of Odoribacter (0.51% vs 0.16%; p-value = 0.044). Correlation analysis revealed that Anaeroplasma and Haemophilus were associated to an unfavourable lipid profile: they correlated negatively to cholesterol and triglycerides related biomarkers and the ratio total to high density lipoprotein (HDL) cholesterol, and positively to HDL size. Odoribacter displayed an opposite behaviour. Faecal SCFAs profile revealed higher abundance of isobutyric (2.76% vs 0.82%, p-value = 0.049) and isovaleric acid (1.32% vs 0.06%, p-value = 0.016) in HC. Isobutyric acid correlated positively with Odoribacter and lipid parameters indicative of an unfavourable profile. BA profile did not show differences between groups. It was concluded that HC subjects showed a particular faecal bacterial signature and SCFAs profile associated with their lipid profile.

Anthocyanin Tissue Bioavailability in Animals: Possible Implications for Human Health. A Systematic Review

Anthocyanins (ACNs) are promising health-enhancing phenolic compounds. We focus on ACN animal tissue bioavailability to provide an evidentiary link between tissue ACNs and their associated health properties. We performed a systematic review of electronic libraries; 279 results were retrieved, and 13 publications met inclusion criteria. Extracted information included animal model employed, administration route, doses, analysis method, and ACN concentration values in tissues. Total ACN concentrations were detected in mice kidney (2.17 × 10⁵ pmol/g), liver (1.73 × 10⁵ pmol/g), heart (3.6 × 10³ pmol/g), and lung (1.16 × 10⁵ pmol/g); and in pig brain (6.08 × 10³ pmol/g). ACNs showed a predominance of parent ACNs in long-term experiments versus an ACN metabolite predominance in short-term experiments. ACNs detected in animal tissues, such as cyanidin-3-glucoside, suggest it may have an important role in human health. This information could be useful to determine proper ACN-intake biomarkers in biological samples in futures studies.

Validation of Dried Blood Spot Cards to Determine Apple Phenolic Metabolites in Human Blood and Plasma After an Acute Intake of Red-Fleshed Apple Snack

SCOPE

The application of dried blood spot (DBS) cards for the study in human blood of dietary polyphenol bioavailability has been poorly studied.

METHODS AND RESULTS

An analytical method based on blood sampling with DBS cards combined with LC-MS/MS has been developed and validated. To test the method validation, the phenolic metabolites are determined in human blood and plasma obtained after an acute intake of a red-fleshed apple snack in ten volunteers. Capillary blood by finger prick is compared to venous blood by venipuncture and whole blood is also compared to their corresponding venous plasma samples. Moreover, the venous plasma results using DBS cards are compared to those obtained by microElution solid phase extraction (µSPE). The main phenolic metabolites detected in blood and plasma samples are phloretin glucuronide, dihydroxyphenylpropionic acid sulphate, (methyl) catechol sulphate, catechol glucuronide, and hydroxyphenyl-γ-valerolactone glucuronide. No significant differences are observed between capillary blood, venous blood, and plasma samples using DBS, and neither between plasma samples analyzed by DBS or µSPE.

CONCLUSIONS

Finger-prick blood sampling based on DBS appears to be a suitable alternative to the classic invasive venipuncture for the determination of circulating phenolic metabolites in nutritional postprandial studies.

Cardiovascular Benefits of Phenol-Enriched Virgin Olive Oils: New Insights from the Virgin Olive Oil and HDL Functionality (VOHF) Study

SCOPE

The main findings of the "Virgin Olive Oil and HDL Functionality" (VOHF) study and other related studies on the effect of phenol-enriched virgin olive oil (VOO) supplementation on cardiovascular disease are integrated in the present work.

METHODS AND RESULTS

VOHF assessed whether VOOs, enriched with their own phenolic compounds (FVOO) or with those from thyme (FVOOT), improve quantity and functionality of HDL. In this randomized, double-blind, crossover, and controlled trial, 33 hypercholesterolemic subjects received a control VOO (80 mg kg-1 ), FVOO (500 mg kg-1 ), and FVOOT (500 mg kg-1 ; 1:1) for 3 weeks. Both functional VOOs promoted cardioprotective changes, modulating HDL proteome, increasing fat-soluble antioxidants, improving HDL subclasses distribution, reducing the lipoprotein insulin resistance index, increasing endogenous antioxidant enzymes, protecting DNA from oxidation, ameliorating endothelial function, and increasing fecal microbial metabolic activity. Additional cardioprotective benefits were observed according to phenol source and content in the phenol-enriched VOOs. These insights support the beneficial effects of OO and PC from different sources.

CONCLUSION

Novel therapeutic strategies should increase HDL-cholesterol levels and enhance HDL functionality. The tailoring of phenol-enriched VOOs is an interesting and useful strategy for enhancing the functional quality of HDL, and thus, it can be used as a complementary tool for the management of hypercholesterolemic individuals.

Determinants of HDL Cholesterol Efflux Capacity after Virgin Olive Oil Ingestion: Interrelationships with Fluidity of HDL Monolayer

SCOPE

Cholesterol efflux capacity of HDL (CEC) is inversely associated with cardiovascular risk. HDL composition, fluidity, oxidation, and size are related with CEC. We aimed to assess which HDL parameters were CEC determinants after virgin olive oil (VOO) ingestion.

METHODS AND RESULTS

Post-hoc analyses from the VOHF study, a crossover intervention with three types of VOO. We assessed the relationship of 3-week changes in HDL-related variables after intervention periods with independence of the type of VOO. After univariate analyses, mixed linear models were fitted with variables related with CEC and fluidity. Fluidity and Apolipoprotein (Apo)A-I content in HDL was directly associated, and HDL oxidative status inversely, with CEC. A reduction in free cholesterol, an increase in triglycerides in HDL, and a decrease in small HDL particle number or an increase in HDL mean size, were associated to HDL fluidity.

CONCLUSIONS

HDL fluidity, ApoA-I concentration, and oxidative status are major determinants for CEC after VOO. The impact on CEC of changes in free cholesterol and triglycerides in HDL, and those of small HDL or HDL mean size, could be mechanistically linked through HDL fluidity. Our work points out novel therapeutic targets to improve HDL functionality in humans through nutritional or pharmacological interventions.

Phenol-enriched olive oils modify paraoxonase-related variables: A randomized, crossover, controlled trial

SCOPE

Low paraoxonase (PON)1 activities, and high PON1 and low PON3 protein levels are characteristic of cardiovascular disease. Our aim was to assess short- and long-term effects of virgin olive oils (VOO), enriched with their own phenolic compounds (PC; FVOO) or with them plus complementary PC from thyme (FVOOT), on PON-related variables and the mechanisms involved.

METHODS AND RESULTS

Two randomized, controlled, double-blind, and crossover interventions were conducted. In an acute intake study, participants ingested three FVOOs differing in PC content. In a sustained intake study, participants ingested a control VOO and two different FVOOs with the same PC content but differing in PC source. Acute and sustained intake of VOO and FVOO decreased PON1 protein and increased PON1-associated specific activities, while FVOOT yielded opposite results. PON3 protein levels increased only after sustained consumption of VOO. Mechanistic studies performed in rat livers showed that intake of isolated PC from VOO and from thyme modulate mitogen-activated protein kinases and peroxisome proliferator-activated receptors regulating PON synthesis, while a combination of these PCs cancels such regulation.

CONCLUSION

This study reveals that the intake of phenol-enriched FVOOs modulates oxidative balance by modifying PON-related variables according to PC content and source, and this modulation can be perceived as beneficial.

In vitro Metabolomic Approaches to Investigating the Potential Biological Effects of Phenolic Compounds: An Update

Dietary phenolic compounds (PCs) have been receiving interest for their presumed roles in disease prevention. However, there is a lack of studies on the underlying molecular mechanisms. In this regard, in vitrometabolomic approaches are suitable for the investigation of the molecular changes in response to PC exposure. Up to date, the biological effects of PCs have only been examined for PCs from rosemary (Rosmarinus officinalis), olive oil, and resveratrol using cell-based metabolomic approach, although transcriptomic and/or proteomic studies have also been conducted in the same in vitro cell experiment in some cases. Our integral analysis of the reviewed studies suggest that PCs may be involved not only in basic cellular processes or macro- and micro-nutrient metabolism, but also in specific metabolic pathways that have been thoroughly investigated. These modulated pathways could have a clinical impact on neurodegenerative diseases, type 2 diabetes, cancer, and cardiovascular diseases. In conclusion, the in vitro metabolomic approaches provide additional information of the molecular mechanisms involved in disease risk reduction of dietary PCs. In order to elucidate the mechanisms of action of PCs, more metabolomic cell-based studies are needed and testing the physiological conjugated forms of PCs in these cell systems could be of special interest.

Polyphenol rich olive oils improve lipoprotein particle atherogenic ratios and subclasses profile: A randomized, crossover, controlled trial

SCOPE

Lipoprotein particle measures performed by nuclear magnetic resonance (NMR), and associated ratios, may be better markers for atherosclerosis risk than conventional lipid measures. The effect of two functional olive oils, one enriched with its polyphenols (FVOO, 500 ppm), and the other (FVOOT) with them (250 ppm) and those of thyme (250 ppm), versus a standard virgin olive oil (VOO), on lipoprotein particle atherogenic ratios and subclasses profiles was assessed.

METHODS AND RESULTS

In a randomized, double-blind, crossover, controlled trial, 33 hypercholesterolemic individuals received 25 mL/day of VOO, FVOO, and FVOOT. Intervention periods were of 3 weeks separated by 2-week washout periods. Lipoprotein particle counts and subclasses were measured by NMR. Polyphenols from olive oil and thyme modified the lipoprotein subclasses profile and decreased the total LDL particle/total HDL particle (HDL-P), small HDL/large HDL, and HDL-cholesterol/HDL-P ratios, and decreased the lipoprotein insulin resistance index (LP-IR) (p < 0.05).

CONCLUSION

Olive oil polyphenols, and those from thyme provided benefits on lipoprotein particle atherogenic ratios and subclasses profile distribution. Polyphenol-enriched olive oil is a way of increasing the olive oil healthy properties while consuming the same amount of fat, as well as a useful and complementary tool for the management of cardiovascular risk individuals.

Virgin Olive Oil Enriched with Its Own Phenols or Complemented with Thyme Phenols Improves DNA Protection against Oxidation and Antioxidant Enzyme Activity in Hyperlipidemic Subjects

The effects of virgin olive oil (VOO) enriched with its own phenolic compounds (PC) and/or thyme PC on the protection against oxidative DNA damage and antioxidant endogenous enzymatic system (AEES) were estimated in 33 hyperlipidemic subjects after the consumption of VOO, VOO enriched with its own PC (FVOO), or VOO complemented with thyme PC (FVOOT). Compared to pre-intervention, 8-hydroxy-2'-deoxyguanosine (a marker for DNA damage) decreased in the FVOO intervention and to a greater extent in the FVOOT with a parallel significant increase in olive and thyme phenolic metabolites. Superoxide dismutase (AEES enzyme) significantly increased in the FVOO intervention and to a greater extent in the FVOOT with a parallel significant increase in thyme phenolic metabolites. When all three oils were compared, FVOOT appeared to have the greatest effect in protecting against oxidative DNA damage and improving AEES. The sustained intake of a FVOOT improves DNA protection against oxidation and AEES probably due to a greater bioavailability of thyme PC in hyperlipidemic subjects.

Effect of daily intake of pomegranate juice on fecal microbiota and feces metabolites from healthy volunteers

SCOPE

The purpose of the study was to evaluate the effect, regarding the metabolic and microbial profile of feces, of diet supplementation of healthy adults with pomegranate juice (PJ).

METHODS AND RESULTS

Twelve healthy adults were recruited to the study, which consisted of the intake of 200 mL/day of PJ during 4 weeks. Feces were collected before and after the supplementation with PJ. Metabolites (phenolic catabolites, short-chain fatty acids, and fecal steroids) and microbial profile were analyzed at baseline and at 4 weeks. Fecal phenolic metabolites, 3-phenylpropionic acid, catechol, hydroxytyrosol, and urolithin A, showed a significant increase in their concentration after supplementation with PJ. Among fecal steroids, parallel to the significant increase of cholesterol concentration, a significant decrease of coprostanol was observed. Although no significant changes in the microbiota profile were observed, different relationships between initial microbiota and the metabolites produced were found. Catechol showed positive and negative correlation with Oscillospora and Paraprevotella genera, respectively, and 3-phenylpropionic acid was positively correlated with Odoribacter genus.

CONCLUSION

Inclusion of PJ in the diet did not significantly alter the gut microbiota composition in healthy adults, but the individual bacterial composition could contribute to the generation of potential health-promoting phenolic metabolites.

The effect of quercetin and kaempferol aglycones and glucuronides on peroxisome proliferator-activated receptor-gamma (PPAR-γ)

Quercetin and kaempferol increase PPAR-γ mediated gene expression without acting as agonistic ligands; glucuronidation reduces their activity in cell-based assays.

Impact of various factors on pharmacokinetics of bioactive polyphenols: an overview

Several epidemiological studies throughout the years have suggested that polyphenols from fruits and vegetables promote health and reduce the risk of certain chronic and neurodegenerative diseases. Yet, it has been proved to be extremely difficult to quantitatively establish the benefit afforded by polyphenols, principally due to the limited understanding of the extent of its absorption and metabolic fate. Pharmacokinetics includes the study of the mechanisms of absorption and distribution of an ingested polyphenol, its chemical changes in the body (e.g. by metabolic enzymes), and the effects and routes of excretion of the metabolites. In recent years, there have been major advances in our knowledge of polyphenol absorption and metabolism, and it is apparent that most classes of polyphenols are sufficiently absorbed to have the potential to exert biological effects. The pharmacokinetics of polyphenols includes the same steps as those for orally ingested drugs (LADME) and faces some of the same challenges, including transporters and enzymes. However, unraveling the bioavailability of polyphenols is even more challenging than with drugs, since many other factors, such as the variety in the chemical structure, the food matrix and the gut microbiota, can affect bioavailability of polyphenols during digestion. This review focuses on the most relevant factors that influence polyphenol pharmacokinetics, and also on the most recent technological strategies developed to overcome the poor bioavailability of phenolic compounds and thus increase their potential for greater health benefits.

Recent advances in biologically active compounds in herbs and spices: a review of the most effective antioxidant and anti-inflammatory active principles

Spices, like vegetables, fruit, and medicinal herbs, are known to possess a variety of antioxidant effects and other biological activities. Phenolic compounds in these plant materials are closely associated with their antioxidant activity, which is mainly due to their redox properties and their capacity to block the production of reactive oxygen species. More recently, their ability to interfere with signal transduction pathways involving various transcription factors, protein kinases, phosphatases, and other metabolic enzymes has also been demonstrated. Many of the spice-derived compounds which are potent antioxidants are of great interest to biologists and clinicians because they may help protect the human body against oxidative stress and inflammatory processes. It is important to study the bioactive compounds that can modulate target functions related to defence against oxidative stress, and that might be used to achieve health benefits individually. In the present review, an attempt has been made to summarize the most current scientific evidence about the in vitro and in vivo effects of the bioactive compounds derived from herbs and spices, focused on anti-inflammatory and antioxidant effects, in order to provide science-based evidence for the traditional uses and develop either functional foods or nutraceuticals.