A rapid HPLC-MS/MS method for the simultaneous determination of luteolin, resveratrol and their metabolites in rat plasma and its application to pharmacokinetic interaction studies.

Both luteolin (LUT) and resveratrol (RES) are natural polyphenols that exert therapeutic effects on liver injuries. Extensive glucuronidation by uridine diphosphate-glucuronosyltransferases 1As (UGT1As) results in poor bioavailability of LUT, which limits its clinical application. As an inhibitor of UGT1A1 and UGT1A9, RES may affect the bioavailability of LUT. The purpose of this study was to develop and validate an HPLC-MS/MS method for the simultaneous determination of LUT, luteolin-3'-O-glucuronide (LUT-3'-G), RES and resveratrol-3-O-glucuronide (RES-3-G) in rat plasma to investigate the effects of RES on the bioavailability and metabolism of LUT after coadministration. The samples were extracted by protein precipitation with methanol using daidzein and naringenin as the internal standards. Separation was achieved on an XBridgeTM C18 column by isocratic elution using 88% methanol-12% water with 2 mM ammonium acetate and 0.01% formic acid. Multiple reaction monitoring mode with a negative electrospray ionization interface was used for quantification of the analytes. The calibration curves were linear over the concentration ranges of 1-1000 (r > 0.995), 2-2000 (r > 0.999), 5-5000 (r > 0.998) and 10-40000 ng/mL (r > 0.996) for LUT, LUT-3'-G, RES and RES-3-G, respectively. The method was fully validated in terms of accuracy, precision, matrix effect, recovery and stability. The validated data met the acceptance criteria in FDA guidelines. The method was successfully applied in a pharmacokinetic interaction study of LUT and RES. The results indicated that RES had a significant effect on the enhanced bioavailability of LUT by reducing the major glucuronidation metabolite in rats, which provides a reference for the combination of LUT and RES in liver diseases.

Development of a novel UPLC-MS/MS method for the simultaneously quantification of polydatin and resveratrol in plasma: Application to a pharmacokinetic study in rats.

The purpose of this study is to develop a sensitive LC-MS-MS method to simultaneously quantify polydatin and its metabolite, resveratrol, for its application in a pharmacokinetic (PK) study and to determine polydatin hydrolysis by microflora. A Shimadzu UHPLC system coupled to an AB Sciex QTrap 4000 mass spectrometer was used for the analysis. Separation was achieved using an Acquity BEH C18 column (2.1 × 50 mm) with acetonitrile and 0.1% formic acid as the mobile phases. Analysis was performed under negative ionization mode using the multiple reaction monitoring (MRM) approach. The method was linear in the range of 9.77-1250 nM for both resveratrol and polydatin with correlation coefficient values >0.99. Themethodhas been shown to be reproducible, with intra- and inter-day accuracy and precision ±10.4% of nominal values, for both analytes. The average extraction recovery rates were 81.78-98.3% for polydatin and 86.4-103.2% for resveratrol, respectively. Matrix effect was in the acceptable range (<15%). The analytes in plasma were found to be stable under bench-top, freeze-thaw, and storage (-4 °C) conditions. The metabolic studies showed that polydatin can be rapidly hydrolyzed by rat fecal S9 fractions and PK studies showed that both polydatin and resveratrol were exposed in the plasma and variable tissues. This novel UPLC-MS-MS method can quantify the levels of both polydatin and its major metabolite resveratrol in biological samples.

Construction of Fe3O4/SiO2/chitosan-grafted-poly(N-vinylcaprolactam) magnetic nanocomposite and their application in simultaneous extraction of Trans-resveratrol and its metabolites from rat plasma.

A novel magnetic nanocomposite of chitosan-grafted-poly(N-vinylcaprolactam) (Fe3O4/SiO2/CHT-g-PNVCL MNC) were synthesized. Chitosan was prepared from shrimp shells Penaeus monodon by a green deacetylation approach. N-vinylcaprolactam was first polymerized on the surface of Fe3O4 magnetic nanoparticles using surface-initiated atom transfer radical polymerization. Then, the Fe3O4 nanoparticles modified with carboxyl-terminated- poly(N-vinylcaprolactam) was grafted onto chitosan. Various techniques were used to characterize of physicochemical properties of synthesized nanomaterials. The application of Fe3O4/SiO2/CHT-g-PNVCL MNC was utilized as a novel adsorbent for the simultaneous extraction of trans-resveratrol and its major phase II metabolites from rat plasma. A qualitative analysis was performed using ultra-performance liquid chromatography triple-quadrupole tandem mass spectrometry. Response surface methodology based on central composite design was used to optimize the extraction procedure including pH, amount of adsorbent, extraction time, desorption time, and volume of elution solvent. The established quantitative method succeeded in satisfying FDA requirements regarding biological analysis methods. The results of the validation of the method indicated its acceptable accuracy (-4.4 to 6.9%), linearity (r > 0.995), precision (CV < 6.3%), and stability. The lower limits of quantification of the proposed method achieved were 1.23-1.68 ngmL-1for target analytes. The information obtained from the method validation has been used to estimate the expanded uncertainty for the determination of trans-resveratrol in rat plasma samples following orally administered trans-resveratrol. The method was applied to study the pharmacokinetics, metabolism, and bioavailability of trans-resveratrol in healthy rats following a single oral or intravenous dose.

DPPC-coated lipid nanoparticles as an inhalable carrier for accumulation of resveratrol in the pulmonary vasculature, a new strategy for pulmonary arterial hypertension treatment.

In this study, we investigated the feasibility of dipalmitoylphosphatidylcholine-coated lipid nanoparticles (DPPC-LNs) as a carrier for preferential accumulation into lungs of Resveratrol (Res), a potentially promising drug for the treatment of pulmonary arterial hypertension (PAH). Res-loaded DPPC-LNs were prepared following a thin film hydration-ultrasonic dispersion technique using glyceryl monostearate as lipid core. DPPC can reduce the interactions between nanoparticles and pulmonary surfactant. The optimal formulation was prepared and characterized for physicochemical properties, storage stability and in vitro release profiles. The optimal formulation was evaluated for uptake by pulmonary arterial smooth muscle cells (PASMCs) using fluorescence microscopy. The efficacy of Res-loaded DPPC-LNs in reducing hyperplasia was tested in 5-HT induced proliferated PASMCs. The drug absorption profiles upon intratracheal administration were monitored in healthy rats. Optimized spherical DPPC-LNs - with mean size of 123.7 nm, zeta potential of -19.4 mV and entrapment efficiency of 94.40% - exhibited an 80% cumulative drug release over 48 h. Fluorescence microscopic study revealed an time-dependent enhancement of cellular uptake of Rh123-labeled DPPC-LNs by PASMCs. PASMC proliferation induced by 5-HT was significantly inhibited by Res-loaded DPPC-LNs. Optimized DPPC-LNs appeared to be safe when incubated with PASMCs. Besides, plasma and lung tissue data analysis indicated higher value of accumulation after intratracheal administration of Res-loaded DPPC-LNs in comparison with the intravenously dosed Res solution, indicating longer retention of Res in the lungs and their slower entry to the systemic blood circulation. DPPC-LNs could be a viable delivery system for site-specific treatment of PAH.

The bitter taste receptor TAS2R14 regulates resveratrol transport across the human blood-cerebrospinal fluid barrier.

The regulation of transport mechanisms at brain barriers must be thoroughly understood, so that novel strategies for improving drug delivery to the brain can be designed. The blood-cerebrospinal fluid barrier (BCSFB) established by the choroid plexus (CP) epithelial cells has been poorly studied in this regard despite its relevance for the protection of the central nervous system (CNS). This study assessed the role of bitter taste receptors (TAS2Rs), TAS2R14 and TAS2R39, in the transport of resveratrol across CP epithelial cells using an in vitro model of the human BCSFB. Both receptors are expressed in human CP cells and known to bind resveratrol. First, Ca2+ imaging assays demonstrated that resveratrol specifically activates the TAS2R14 receptor, but not TAS2R39, in these human CP epithelial cells. Then, we proceeded with permeation studies that showed resveratrol can cross the human BCSFB, from the blood to the CSF side and that TAS2R14 knockdown decreased the transport of resveratrol across these cells. Conversely, inhibition of efflux transporters ABCC1, ABCC4 or ABCG2 also restrained the transport of resveratrol across these cells. Interestingly, resveratrol upregulated the expression of ABCG2 located at the apical membrane of the cells via TAS2R14, whereas ABCC1 and ABCC4 at the basolateral membrane of the cells were not affected. Altogether, our study demonstrates that the BCSFB is a gateway for resveratrol entrance into the CNS and that the receptor TAS2R14 regulates its transport by regulating the action of efflux transporters at CP epithelial cells.

Subcutaneous maternal resveratrol treatment increases uterine artery blood flow in the pregnant ewe and increases fetal but not cardiac growth.

KEY POINTS: Substrate restriction during critical developmental windows of gestation programmes offspring for a predisposition towards cardiovascular disease in adult life. This study aimed to determine the effect of maternal resveratrol (RSV) treatment in an animal model in which chronic fetal catheterisation is possible and the timing of organ maturation reflects that of the human. Maternal RSV treatment increased uterine artery blood flow, fetal oxygenation and fetal weight. RSV was not detectable in the fetal circulation, indicating that it may not cross the sheep placenta. This study highlights RSV as a possible intervention to restore fetal substrate supply in pregnancies affected by placental insufficiency. ABSTRACT: Suboptimal in utero environments with reduced substrate supply during critical developmental windows of gestation predispose offspring to non-communicable diseases such as cardiovascular disease (CVD). Improving fetal substrate supply in these pregnancies may ameliorate the predisposition these offspring have toward adult-onset CVD. This study aimed to determine the effect of maternal resveratrol (RSV) supplementation on uterine artery blood flow and the direct effects of RSV on the fetal heart in a chronically catheterised sheep model of human pregnancy. Maternal RSV treatment significantly increased uterine artery blood flow as measured by phase contrast magnetic resonance imaging, mean gestational fetal PaO2 and SaO2 as well as fetal weight. RSV was not detectable in the fetal circulation, and mRNA and protein expression of the histone/protein deacetylase SIRT1 did not differ between treatment groups. No effect of maternal RSV supplementation on AKT/mTOR or CAMKII signalling in the fetal left ventricle was observed. Maternal RSV supplementation is capable of increasing fetal oxygenation and growth in an animal model in which cardiac development parallels that of the human.

Simultaneous ultra-performance liquid chromatography-tandem mass spectrometry determination of six components in rat plasma after oral administration of Smilacis glabrae Roxb. extract.

In this study, an accurate and reliable method of ultra-performance liquid chromatography coupled with a triple-quadrupole tandem mass spectrometry was firstly developed and fully validated for the simultaneous determination of epicatechin, neoastilbin, astilbin, isoastilbin, engeletin and resveratrol in rat plasma after administration of Smilacis glabrae Roxb. extract. Naringenin was used as an internal standard (IS). The analyte and IS were separated on a C18 column by gradient elution with a mobile phase of acetonitrile-0.3% acetic acid at a flow rate of 0.25 mL/min for a total run time of 8 min. The method was validated in terms of selectivity, linearity, precision, accuracy, extraction recovery, matrix effect and stability. The developed method was successfully applied to determine the main pharmacokinetic parameters of six components in rat plasma.

A validated stability-indicating HPLC method for simultaneous estimation of resveratrol and piperine in cubosome and human plasma.

Resveratrol and piperine are proven for their therapeutic benefits to treat various diseases. Due to their synergistic actions and combined drug delivery application, a rapid and specific RP-HPLC method was developed and validated as per ICH guidelines, by using an isosbestic point. The chromatographic separation was performed with Luna 5 µ 100 ŠC-18(2) HPLC column by using acetonitrile (ACN): phosphate buffer (0.01% orthophosphoric acid) (55:45) as mobile phase, at 1 mL/min of flow rate and 330 nm. The developed method was found to be linear over the concentration range of 0.25-8 µg/mL with correlation coefficient value >0.999. The developed method was accurate (percent recovery 98.06-101.74%), precise (percent relative standard deviation <2.0%), and robust. The limit of detection and limit of quantification for resveratrol were found to be 0.02 and 0.08 µg/mL, respectively and 0.04 and 0.11 µg/mL, for piperine, respectively. The developed method was also validated in human plasma as per ICH guidelines. Moreover, stress degradation studies of both phytoconstituents were studied and the relevancy of the developed method was analyzed on cubosome nanoformulation. A good separation of drug peaks was observed in the presence of the degradation products. This method could thus be used for regular in vitro and in vivo estimation of piperine and resveratrol.

Antioxidant effect of resveratrol in single red blood cells measured by thermal fluctuation spectroscopy.

The human red blood cell (RBC) membrane has significant elastic capabilities which can be described measuring typical membrane edge fluctuations and mechanical properties by optical techniques. The RBC elastic properties can be affected by changes in the surrounding media. In an attempt to elucidate the molecular mechanisms of the interaction of resveratrol with the red cell membrane and of its antioxidant capacity the changes in mechanical properties of the RBC membrane were analyzed. These studies were carried out through measurements of RBC membrane fluctuations in the presence of the oxidant agent HClO using thermal fluctuation spectroscopy (TFS). The observed results showed that the elastic capabilities of RBC changed with low concentration of hypochlorous acid but without morphological changes. However, in the presence of resveratrol the deformation and decrease of elastic capabilities induced by HClO on RBC decreased. These in vitro results demonstrated the protective effect of RV against the detrimental effects triggered by HClO upon human erythrocytes.

Simultaneous Determination of Curcumin and Resveratrol in Lipidic Nanoemulsion Formulation and Rat Plasma Using HPLC: Optimization and Application to Real Samples.

Background: Curcumin and resveratrol are naturally occurring polyphenols that are highly effective in inhibiting the growth of cancer cells. A robust reversed-phase HPLC method has been developed for the simultaneous determination of these two natural drugs. Objective: The method was adapted to analyze both drugs in pure forms, in lipidic nanoemulsion formulation as well as in rat plasma. The method was applied to real samples after intravenous (IV) injection of rats. Method: Analysis utilized C18 column using acetonitrile (ACN)-water (pH adjusted to 4.6 by 1% orthophosphoric acid) in the ratio of 55+45 (v/v) at a flow rate of 0.8 mL/min with detection at 425 and 304 nm for curcumin and resveratrol, respectively. Results: Extraction efficiency of curcumin and resveratrol using ACN-methanol was 96.10-101.00% (RSD 2.49) and 95.00-99.87% (RSD 2.59), respectively. The assay was linear from 0.05 to 4.00 µg/mL (correlation coefficient of 0.9989 and 0.9981, respectively) and precise [average interday and intraday precision for curcumin RSD% (0.45, 2.04) and resveratrol RSD% (2.25, 1.71)] in spiked rat plasma. The LOD and LOQ were found to be (0.0085 µg/mL, 0.025 µg/mL) and (0.02, 0.06), respectively. Conclusions: The data presented demonstrate that the method provides rapid, sensitive, and precise determination of curcumin and resveratrol in spiked rat plasma and in nanoemulsion dosage form without tedious cleanup procedure, which was successfully applied for quantitation of both drugs following their IV administration to albino rats. Highlights: Validated chromatographic method has been developed for simultaneous determination of curcumin and resveratrol. Optimization of chromatographic conditions was achieved. Application of the method on nanoemulsion formula, on spiked rat plasma, and pharmacokinetics study.

Effects of Grape Pomace Polyphenolic Extract (Taurisolo®) in Reducing TMAO Serum Levels in Humans: Preliminary Results from a Randomized, Placebo-Controlled, Cross-Over Study.

Trimethylamine N-oxide (TMAO) is considered a novel risk factor for cardiovascular diseases. Several studies demonstrated that polyphenols are able to inhibit the growth of TMA-producing bacterial strains, and resveratrol (RSV) reduced TMAO levels in mice. In the present study, we evaluated the TMAO-reducing effect of a novel nutraceutical formulation containing grape pomace extract in humans (Taurisolo®). The Taurisolo® polyphenol content was evaluated by a High Performance Liquid Chromatography-diode-array detector (HPLC-DAD) method, and RSV was monitored as an indicative marker. After in vitro GI digestion, intestinal bioaccessibility of RSV was 92.3%. A randomized, placebo-controlled, cross-over trial was carried out to evaluate the TMAO-reducing effect of Taurisolo®. In acute, the maximum levels of RSV were detected both in serum and whole blood 60 min after the administration of Taurisolo®; in chronic, a significant increase of RSV was detected in serum after the 4-week treatment. After 4 weeks, the levels of TMAO were significantly decreased in the treatment group compared to placebo (63.6% vs. 0.54%, respectively, P < 0.0001). In conclusion, our data show that Taurisolo® may represent a novel and useful natural remedy to reduce prognostic markers for incident cardiovascular events. Undoubtedly, further in vitro and in vivo studies need to be performed in order to elucidate possible mechanisms of action and corroborate our preliminary results.

Resveratrol and Its Human Metabolites-Effects on Metabolic Health and Obesity.

Resveratrol is one of the most widely studied polyphenols and it has been assigned a plethora of metabolic effects with potential health benefits. Given its low bioavailability and extensive metabolism, clinical studies using resveratrol have not always replicated in vitro observations. In this review, we discuss human metabolism and biotransformation of resveratrol, and reported molecular mechanisms of action, within the context of metabolic health and obesity. Resveratrol has been described as mimicking caloric restriction, leading to improved exercise performance and insulin sensitivity (increasing energy expenditure), as well as having a body fat-lowering effect by inhibiting adipogenesis, and increasing lipid mobilization in adipose tissue. These multi-organ effects place resveratrol as an anti-obesity bioactive of potential therapeutic use.

Can resveratrol supplement change inflammatory mediators? A systematic review and meta-analysis on randomized clinical trials.

BACKGROUND: Resveratrol as a polyphenolic compound might be able to reduce inflammatory mediators. Change in inflammatory state is identified by the measurement of inflammatory mediators such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP). The objective of this study is to conduct a systematic review and meta-analysis on randomized controlled trials that assessed the effect of resveratrol on concentration of serum inflammatory mediators. METHOD: Systematic search was performed up to October 2017 using ISI web of science, PubMed, Scopus, EMBASE, and Google scholar. Weighted mean difference was estimated either by subtracting baseline values from post-intervention value or as the post-intervention values. Fixed effect model was applied to analyze data where heterogeneity was <25%; otherwise, random effects models were applied. The protocol was registered with PROSPERO (No. CRD42018085098). RESULTS: The meta-analysis and systematic review considered 15 trials, involving 658 adults aged 18-75 years. Resveratrol significantly reduced serum CRP levels (WMD = -0.54; 95% CI: -0.78, -0.30; I2 = 77.7%; P < 0.0001), but it had no significant effect on serum IL-6 (WMD = -0.06; 95% CI: -0.27, 0.14; I2 = 62.0%; P = 0.005) and TNF-α levels (WMD = -0.20; 95% CI: -0.55, 0.16; I2 = 87.2%; P < 0.0001). Resveratrol intake reduced TNF-α in young subjects (WMD = -0.34; 95% CI: -0.57, -0.12; I2 = 60.5%; P = 0.038) and obese individuals (WMD = -1.52; 95% CI: -2.87, -0.16; I2 = 74.1%; P = 0.004). CONCLUSION: The analysis indicated possible decreasing effect of resveratrol on CRP, but it might not be able to change IL-6 and TNF-α concentrations. More studies, separately on males and females with obesity, and varied age, are necessary.

Quantification of trans-resveratrol and its metabolites in human plasma using ultra-high performance liquid chromatography tandem quadrupole-orbitrap mass spectrometry.

Trans-resveratrol is a stilbene polyphenol with a large spectrum of biological activities. This is why it is widely studied in terms of activities, bioavailability and quantitation in different foods, beverages and biological matrices. Different analytical methods are employed for its quantitation. In this study a quadrupole-orbitrap tandem mass spectrometer coupled to a reverse phase ultra-high performance liquid chromatography is applied to a quantitation of trans-resveratrol and its metabolites trans-resveratrol-3-O-ß-d-glucuronide, trans-resveratrol-4'-O-ß-d-glucuronide, trans-resveratrol-3-O-sulfate, a,b-dihydroresveratrol, a,b-dihydroresveratrol-glucuronide, a,b-dihydroresveratrol-glucuronide-sulfate, a,b-dihydroresveratrol-sulfate, trans-resveratrol-3,5-O-ß-d-diglucuronide, trans-resveratrol-3,4'-O-d-ß-diglucuronide, trans-resveratrol-3-O-ß-d-glucuronide-sulfate and trans-resveratrol-4'-O-ß-d-glucuronide-sulfate in human plasma. MS/MS experiments coupled to a high resolving power and accurate mass measurements as well as the use of labeled internal standards enabled the achievement of linear calibration curves across the four orders of magnitude concentration ranges. The method was validated in terms of specificity and selectivity, accuracy and precision, sensitivity and matrix effect and can be now applied to pharmacokinetic studies or routine analysis. In addition, the application of quadrupole-orbitrap mass spectrometer to the quantitation of trans-resveratrol and its metabolites provides acquisition of full collision induced dissociation spectra of analyzed compounds giving place to the structural characterization and sensitivity and linear concentration ranges respecting the accuracy and precision, specificity and selectivity requirements.

Resveratrol, Metabolic Syndrome, and Gut Microbiota.

Resveratrol is a polyphenol which has been shown to have beneficial effects on metabolic syndrome-related alterations in experimental animals, including glucose and lipid homeostasis improvement and a reduction in fat mass, blood pressure, low-grade inflammation, and oxidative stress. Clinical trials have been carried out to address its potential; however, results are still inconclusive. Even though resveratrol is partly metabolized by gut microbiota, the relevance of this "forgotten organ" had not been widely considered. However, in the past few years, data has emerged suggesting that the therapeutic potential of this compound may be due to its interaction with gut microbiota, reporting changes in bacterial composition associated with beneficial metabolic outcomes. Even though data is still scarce and for the most part observational, it is promising nevertheless, suggesting that resveratrol supplementation could be a useful tool for the treatment of metabolic syndrome and its associated conditions.

Phenolic metabolites in plasma and tissues of rats fed with a grape pomace extract as assessed by liquid chromatography-tandem mass spectrometry.

Grape pomace extract (GPE) is a rich and relatively low-cost source of phenolic compounds. However, little is known about the main GPE metabolites in mammals, which could help explain the observed health-promoting effects. This study investigated the presence of parent compounds from flavanol, flavonol and stilbene families and their metabolites in rat plasma and tissues after an acute intake of GPE in doses of 300 and 600 mg kg/body weight. The measurement of free compounds and their metabolites was performed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Results showed the presence of epicatechin, epicatechin methyl-glucuronide, epicatechin methyl-sulphate, catechin, catechin-glucuronide, quercetin methyl-glucuronide, resveratrol-3-glucuronide, resveratrol-4-glucuronide and resveratrol-3-sulphate in plasma, which was dose dependent. The most abundant measured compound in plasma was epicatechin-glucuronide. The presence of glucuronidated and methyl-glucuronidated forms of catechin were observed in the liver at both doses, while epicatechin-glucuronide and methyl-glucuronide were detected only upon intake of 600 mg GPE/kg body weight. At this dose epicatechin-glucuronide and methyl-glucuronide were also detected in muscle, and catechin methyl-glucuronide in adipose tissue. Results show the main GPE metabolites present in rat tissues after oral consumption, contributing to better understand the health benefits of GPE and its potential utilization as a functional ingredient.

The Oral Bioavailability of Trans-Resveratrol from a Grapevine-Shoot Extract in Healthy Humans is Significantly Increased by Micellar Solubilization.

SCOPE: Grapevine-shoot extract Vineatrol30 contains abundant resveratrol monomers and oligomers with health-promoting potential. However, the oral bioavailability of these compounds in humans is low (˂1-2%). The aim of this study was to improve the oral bioavailability of resveratrol from vineatrol by micellar solubilization. METHODS AND RESULTS: Twelve healthy volunteers (six women, six men) randomly ingested a single dose of 500 mg vineatrol (30 mg trans-resveratrol, 75 mg trans-ε-viniferin) as native powder or liquid micelles. Plasma and urine were collected at baseline and over 24 h after intake. Resveratrol and viniferin were analyzed by HPLC. The area under the plasma concentration-time curve (AUC) and mean maximum plasma trans-resveratrol concentrations were 5.0-fold and 10.6-fold higher, respectively, after micellar supplementation relative to the native powder. However, no detectable amounts of trans-ε-viniferin were found in either plasma or urine. The transepithelial permeability of trans-resveratrol and trans-ε-viniferin across differentiated Caco-2 monolayers was consistent to the absorbed fractions in vivo. CONCLUSION: The oral bioavailability of trans-resveratrol from the grapevine-shoot extract Vineatrol30 was significantly increased using a liquid micellar formulation, without any treatment-related adverse effects, making it a suitable system for improved supplementation of trans-resveratrol.

Global testing of shifts in metabolic phenotype.

INTRODUCTION: Current metabolomics approaches to unravel impact of diet- or lifestyle induced phenotype variation and shifts predominantly deploy univariate or multivariate approaches, with a posteriori interpretation at pathway level. This however often provides only a fragmented view on the involved metabolic pathways. OBJECTIVES: To demonstrate the feasibility of using Goeman's global test (GGT) for assessment of variation and shifts in metabolic phenotype at the level of a priori defined pathways. METHODS: Two intervention studies with identified phenotype variations and shifts were examined. In a weight loss (WL) intervention study obese subjects received a mixed meal challenge before and after WL. In a polyphenol (PP) intervention study obese subjects received a high fat mixed meal challenge (61E% fat) before and after a PP intervention. Plasma samples were obtained at fasting and during the postprandial response. Besides WL- and PP-induced phenotype shifts, also correlation of plasma metabolome with phenotype descriptors was assessed at pathway level. The plasma metabolome covered organic acids, amino acids, biogenic amines, acylcarnitines and oxylipins. RESULTS: For the population of the WL study, GGT revealed that HOMA correlated with the fasting levels of the TCA cycle, BCAA catabolism, the lactate, arginine-proline and phenylalanine-tyrosine pathways. For the population of the PP study, HOMA correlated with fasting metabolite levels of TCA cycle, fatty acid oxidation and phenylalanine-tyrosine pathways. These correlations were more pronounced for metabolic pathways in the fasting state, than during the postprandial response. The effect of the WL and PP intervention on a priori defined metabolic pathways, and correlation of pathways with insulin sensitivity as described by HOMA was in line with previous studies. CONCLUSION: GGT confirmed earlier biological findings in a hypothesis led approach. A main advantage of GGT is that it provides a direct view on involvement of a priori defined pathways in phenotype shifts.