Application of toasted vine-shoot chips and ultrasound treatment in the ageing of Primitivo wine.

Ageing wine in barrels is an historical practice used to improve the aromatic complexity of wine, but due to the high cost and the long ageing period, alternative approaches have been developed, such as the use of wood chips and ultrasound treatment. The present paper reports the results of an investigation performed on wine (cv. Primitivo). Three treatments were investigated: a) control wine untreated; b) wine with toasted vine-shoot chips (10 g/L); c) wine with toasted vine-shoot chips (10 g/L) and treated by ultrasound. Wines were analysed after 7, 14, 21, and 28 days. The application of ultrasound combined with vine-shoot chips promoted tannin evolution, thereby accelerating the ageing process of wine. The chips addition decreased the total anthocyanins content and increased the stilbenes (trans-resveratrol and trans-piceid) and wood-related aromas (i.e., furfural, 5-methylfurfural) concentration. Finally, wines added with chips were richer in woody, vanilla, oak, and chocolate notes and more preferred by the tasters.

Increase in plasma resveratrol levels and in acid-resistant proteins in the acquired enamel pellicle after use of resveratrol-containing orodispersible tablets.

OBJECTIVE: This study evaluated the effect of administration of trans-resveratrol-containing orodispersible tablets on the protein composition of the AEP and on blood plasma trans-resveratrol concentrations. METHODS: Ten volunteers participated in two crossover double-blind phases. In each phase, after dental prophylaxis, they received a trans-resveratrol (15 mg) orodispersible tablet, or a placebo tablet (without actives). The AEP formed after 120 min was collected with electrode filter papers soaked in 3 % citric acid. Blood samples were collected 30, 45, 60 and 120 min after the use of the tablet. After protein extraction, AEP samples were analyzed by shotgun labelfree quantitative proteomics and plasma samples were analyzed by high-performance liquid chromatography (HPLC). RESULTS: Eight hundred and two proteins were identified in the AEP. Among them, 336 and 213 were unique to the trans-resveratrol and control groups, respectively, while 253 were common to both groups. Proteins with important functions in the AEP had increased expression in the trans-resveratroltreated group, such as neutrophil defensins, S100 protein isoforms, lysozyme C, cystatin-D, mucin-7, alphaamylase, albumin, haptoglobin and statherin. Trans-resveratrol was detected in the plasma at all the times evaluated, with the peak at 30 min. CONCLUSIONS: The administration of trans-resveratrol in sublingual orodispersible tablets was effective both to increase the bioavailability of the polyphenol and the expression of antibacterial and acid-resistant proteins in the AEP, which might benefit oral and general health.

Metabolite profiling reveals the influence of grapevine genetic distance on the chemical signature of juices.

BACKGROUND: Yield, disease tolerance, and climate adaptation are important traits in grapevine genetic breeding programs. Selection for these characteristics causes unpredictable changes in primary and specialized metabolism, affecting the physicochemical properties and chemical composition of the berries and their processed products, juice, and wine. In this study, we investigated the influence of the genetic distance between grapevine genotypes on the chemical signatures of the juices, by integrating comprehensive metabolic profiling to genetic analyses. RESULTS: The studied grapevine cultivars exhibited low genetic diversity. Breeding for agronomic traits promoted higher contents of soluble sugars, total phenolics, and anthocyanins in the juices. Untargeted juice metabolomics identified a total of 147 metabolites, consisting of 30 volatiles, 21 phenolics, and 96 ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) features. Juices from grapes of the most recent cultivars exhibited increased levels of trans-resveratrol, catechin, and luteolin. The blend of volatiles from juices of later cultivars was also more complex, consisting of 29 distinct metabolites in 'BRS Magna'. Grapes from 'BRS Carmem', an intermediate cultivar, gave the most divergent UHPLC-MS juice profile. CONCLUSION: Contents of soluble solids, total phenolics, and anthocyanins in grape juices were increased by controlled crosses and hybrid selection. Integrative analyses demonstrated that the juices' metabolic profiles accurately represent the cultivars' genetic distances. Juices from 'BRS Violeta' and 'BRS Magna' show relevant positive association with health-related phenolics and a distinct set of odor volatiles, although these characteristics were specifically sought by breeding. © 2023 Society of Chemical Industry.

Derivatization-Based Novel Chromatographic and Spectrophotometric Methods for the Simultaneous Determination of Gymnemic Acid and Resveratrol in Antidiabetic Polyherbal Formulation.

Herbal medicine is widely used for the treatment and prevention of various ailments, highlighting the importance of ensuring its consistency and quality. This research focuses on the simultaneous detection of Gymnemic acid (GYM) and Resveratrol (RES) in an antidiabetic polyherbal formulation as no reported method exists for their simultaneously detection. The objective of this study is to develop and validate novel derivatization-based spectrometric and HPTLC methods for the simultaneous determination of GYM and RES. The spectrophotometric method involved derivatization of GYM with benzoyl chloride, followed by measurement of absorbance at 349 nm an isoabsorptive point. The HPTLC method utilized post derivatization with vanillin-sulfuric acid, and its separation was achieved on pre-coated silica gel 60GF254 using chloroform:methanol:glacial acetic acid (13:4:0.1, v/v/v) as mobile phase and estimated at 575 nm. The developed method exhibits linearity, accuracy, precision, LOD, LOQ, specificity and robustness in accordance with the ICH Q2 (R1) guideline. The percent assay of GYM and RES in the marketed capsule formulation was statistically compared using an unpaired t-test, resulting in a range of 99.51-102.65%. These indicate no significant difference between the proposed method and the marketed formulation. Therefore, both novel methods can be interchangeably used for quality control of GYM and RES in polyherbal formulations.

Effects of Plant-Derived Polyphenols on the Antioxidant Activity and Aroma of Sulfur-Dioxide-Free Red Wine.

Significant efforts have been made in recent years to produce healthier wines, with the primary goal of reducing the use of sulfur dioxide (SO2), which poses health risks. This study aimed to assess the effectiveness of three plant-derived polyphenols (dihydromyricetin, resveratrol, and catechins) as alternatives to SO2 in wine. After a three-month aging process, the wines were evaluated using analytical techniques such as high-performance liquid chromatography, colorimetry, gas chromatography-olfactometry-mass spectrometry, as well as electronic nose and electronic tongue analyses, with the purpose to assess parameters including antioxidant activity, color, contents of volatile aroma compounds, and sensory characteristics. The results demonstrated various degrees of improvement in the antioxidant activity, aromatic intensity, and sensory characteristics of wines using polyphenols. Notably, dihydromyricetin (200 mg/L) exhibited the strongest antioxidant activity, with increases of 18.84%, 23.28%, and 20.87% in 2,2-diphenyl-1-picrylhydrazyl, 2,2'azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric-ion-reducing antioxidant power assays, respectively. Resveratrol (200 mg/L) made the most significant contribution to volatile aroma compounds, with an 8.89% increase in the total content of alcohol esters. In E-nose analysis, catechins (200 mg/L) showed the highest response to aromatic compounds and the lowest response to volatile sulfur compounds, while also exhibiting the best sensory characteristics. Therefore, the three plant-derived polyphenols investigated here exhibited the potential to enhance wine quality as alternatives to SO2. However, it is important to consider the specific impact of different polyphenols on wine; hence, suitable antioxidants should be selected in wine production according to specific requirements.

Effect of different oil extraction methods on bioactive compounds, antioxidant capacity and phytochemical profiles of raw flaxseeds (Linum usitatissimum) and after roasting at different temperatures.

BACKGROUND: Factors such as variety, genetics, soil structure and plant diseases affect the oil amount and properties of flaxseed. By applying heat and various extraction treatments to flaxseed, the storage ability of the seed is increased by the removal of moisture, and the stability of phytochemicals in the seed against heat can be determined. RESULTS: Total carotenoid and phenol of flaxseeds changed from 0.13 (control) and 0.61 mg g-1 (120 °C) to 202.64 (control and 90 °C) and 225.69 mg 100 g-1 (120 °C), respectively. While total flavonoid of flaxseed roasted at different temperatures varied between 636.0 (90 °C) and 786.00 mg 100 g-1 (120 °C), antioxidant activity values for raw and roasted flaxseeds between 59.32% (control) and 68.64% (120 °C) were recorded. Oil content of seeds changed between 34.07 and 42.57% (P < 0.05). Viscosity of flaxseed oil extracted using different systems was between 31.95 (cold-pressed; control) and 36.00 mPa s (ultrasonic; 120 °C). The dominant phenolics of flaxseeds were identified as isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol. The oils of flaxseeds contained 55.27-58.23 linolenic, 17.40-18.91 oleic, 14.03-14.84 linoleic and 4.97-5.37 palmitic acids, depending on extraction method and roasting temperature. CONCLUSION: Roasting and oil extraction methods did not have a significant effect on free acidity, but was found to affect peroxide value. The predominant phenolic constituents of flaxseed samples were isorhamnetin, resveratrol, quercetin, catechin, apigenin-7-glucoside and campherol, respectively. The major fatty acids of flaxseed oil were determined as linolenic, oleic, linoleic and palmitic. © 2023 Society of Chemical Industry.

Screening of Tyrosinase, Xanthine Oxidase, and α-Glucosidase Inhibitors from Polygoni Cuspidati Rhizoma et Radix by Ultrafiltration and HPLC Analysis.

Polygoni Cuspidati Rhizoma et Radix (PCR), the rhizome and root of Polygonum cuspidatum Sieb. et Zucc., has been used as an herbal medicine for a long time. In this study, the ultrafiltration combined with high performance liquid chromatography (UF-HPLC) method was developed to screen tyrosinase (TYR), α-glucosidase (α-GLU), and xanthine oxidase (XOD) inhibitors from PCR. Firstly, the inhibitory activity of 50% methanol PCR extract on TYR, α-GLU, XOD, and acetylcholinesterase (ACHE) was tested. The extract showed a good inhibition on the enzymes, except for ACHE. Therefore, UF-HPLC experiments were carried out to screen TYR, α-GLU, and XOD inhibitors from PCR extract. Seven potential bioactive components were discovered, including methylgallate (1), 1,6-di-O-galloyl-D-glucose (2), polydatin-4'-O-D-glucoside (3), resveratrol-4'-O-D-glucoside (4), polydatin (5), malonyl glucoside resveratrol (6), and resveratrol-5-O-D-glucoside (7). Most of them were found as enzyme inhibitors from PCR for the first time, except polydatin (5), which had been reported as an α-GLUI in PCR in the literature. Finally, molecular docking analysis was applied to validate the interactions of these seven potential active components with the enzymes. Compounds 1-7 were proven as TYR inhibitors, compounds 2, 4-7 were identified as XOD inhibitors, and compounds 4-6 were confirmed as α-GLU inhibitors. In short, the current study provides a good reference for the screening of enzyme inhibitors through UF-HPLC, and provides scientific data for future studies of PCR.

Activity of Na+/K+- and Ca2+-ATPases in human erythrocyte membranes: Protocol improvement, relation to cholesterol content, and effects of polyphenols.

It is known that the activities of Na+/K+- and Ca2+-ATPases in the plasma membrane with an excess of cholesterol are compromised. Our main goal was to find out whether quercetin, resveratrol, or caffeic acid, in the nano- and low micromolar concentration ranges, can improve the ATPase activity in human erythrocyte membranes with excess cholesterol. These molecules belong to different chemical classes of polyphenols and are widely present in plant foods. Also, due to some variations in the protocol for determining the ATPase activity, we first analyzed several key parameters of the protocol to improve the accuracy of the results. The activities of Na+/K+- and Ca2+-ATPases were reduced in membranes with moderate and high cholesterol levels compared to membranes from normocholesterolemic subjects (p < 0.01). All three polyphenols affected the ATPase activity in a similar biphasic manner. Namely, the ATPase activity gradually increased with increasing polyphenol concentration up to 80-200 nM, and then gradually decreased with further increase in polyphenol concentration. Moreover, the stimulating effect of the polyphenols was highest in membranes with high cholesterol content, making ATPase activity values close/equal to those in normal cholesterol membranes. In other words, quercetin, resveratrol, and caffeic acid at nanomolar concentrations were able to improve/restore the functioning of Na+/K+- and Ca2+-ATPases in erythrocyte membranes with high cholesterol levels. This suggests a common membrane-mediated mechanism of action for these polyphenols, related to the content of membrane cholesterol.

Germination and its role in phenolic compound bioaccessibility for black mustard grains: A study using INFOGEST protocol.

Germination has been regarded as a promising natural process to improve the antioxidant properties of mustard. However, there ís one question to be solved in this area: does germination improve mustard phenolics' bioaccessibility? The aim of this study was to answer this question by using INFOGEST protocol to simulate in vitro digestion. Resveratrol, formononetin and cryptochlorogenic acid were identified for the first time as evaluated by liquid chromatography-mass spectrometry. In general, digestion positively impacted the antioxidant potential of soluble phenolics from non-germinated and germinated grains, which were probably released from cell wall matrix by digestive enzymes. Although digestion seemed to nullify the antioxidant improvement caused by germination, phenolic quantities were distinctive. The main difference was found for sinapic acid, as its concentration reached a value 1.75-fold higher in germinated digested mustard compared to non-germinated. The results obtained suggested that germination improved the phenolic bioaccessibility of mustard grains, which encourages its use and investigations.

Temperature and light conditions affect stability of phenolic compounds of stored grape cane extracts.

This study aimed to determine the stability of PCs in grape canes extracts stored at different temperatures and light conditions. The PCs composition was monitored every-two weeks during three months by liquid chromatography coupled to diode array and fluorescence detectors (LC-DAD-FLD). Initially, stilbenes represented 87 % of total PCs. Storage at -20 and 5 °C reduced PCs 8 and 6 %, respectively. When extracts were exposed to 25 and 40 °C, the degradation of (+)-catechin and (-)-epicatechin was faster than under lower temperatures, and light accelerated the degradation kinetics. trans-piceatannol showed particularly sensitive to temperature increase, being mostly degraded after two weeks stored at 40 °C. Conversely, degradation of trans-resveratrol and ε-viniferin was mostly catalyzed by light, since nearly 70 % of them were degraded at 40 °C under light, in comparison with a 23 % reduction of trans-resveratrol and no changes of ε-viniferin at 40 °C in darkness.

Multivariate Statistical Analysis for Mutual Dependence Assessment of Selected Polyphenols, Organic Acids and Metals in Cool-Climate Wines.

Polyphenols, organic acids and metal ions are an important group of compounds that affect the human health and quality of food and beverage products, including wines. It is known that a specific correlation between these groups exist. While wines coming from the New World and the Old World countries are extensively studied, wines coming from cool-climate countries are rarely discussed in the literature. One of the goals of this study was to determine the elemental composition of the wine samples, which later on, together as polyphenols and organic acids content, was used as input data for chemometric analysis. The multivariate statistical approach was applied in order to find specific correlations between the selected group of compounds in the cool-climate wines and the features that distinguish the most and differ between red and white wines and rosé wines. Moreover, special attention was paid to resveratrol and its correlation with selected wine constituents.

Drying date plum (Diospyros lotus L.) fruit: Assessing rehydration properties, antioxidant activity, and phenolic compounds.

Date plum (Diospyrus lotus L.) is an edible fruit from the Ebenaceae family, rich in nutrients, and having tremendous medicinal properties. This paper attempted to show the influence of different parameters of convective drying such as temperature (50, 60, 70, and 80°C) and air velocity (0.5, 1.0, and 1.5 m/s) on the shrinkage and microstructure, rehydration properties, antioxidant activity, and phenolic compounds of date plum. The drying caused significant changes in the color, actual size, and distribution of the fruit cells of date plum. The total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) of fresh date plum were 0.81 ± 0.00 mg GAE/g, 0.23 ± 0.10 mg ECE/g, 7.15 ± 1.09 mmol ISE/g, and 14.92 ± 0.88 mmol/TE, respectively. The drying at 70°C had the highest values of TPC, TFC, gallic acid, chlorogenic and syringic acids, catechin, quercetin-3-glucoside, resveratrol, and DPPH. The drying air velocities showed no significant effects on the antioxidant contents and the antioxidant activity. Of the models applied to the drying kinetics, the Midilli model was found as the best model to describe the drying kinetics of date plum. In addition, the Weibull model was found as the most successful among the models applied to the rehydration kinetics of date plum. According to the achieved findings, the convective drying temperature of 70°C is the optimum temperature to produce the dehydrated date plum. Practical Application This work has revealed the drying conditions responsible for preserving the phenolic compounds, total flavonoid content, and antioxidant features of D. lotus L. The study found the optimum drying conditions, and Midilli and Weibull models were the most fitted models to describe the drying and rehydration behaviors of D. lotus L. fruits, respectively. The drying provides a reasonable value of the possibility of continuous consumption of the fruits dried afforded on off-seasons. The dried fruits are widely used for multipurpose and have been extensively used in food industries due to their rich nutraceutical and antioxidant compounds.

Study of Inducing Factors on Resveratrol and Antioxidant Content in Germinated Peanuts.

When peanuts germinate, bioactive compounds such as resveratrol (RES), γ-aminobutyric acid (GABA), isoflavones, and polyphenol compounds are generated. Peanut kernels were germinated in the dark for two days, and stimuli including soaking liquid, rice koji, high-pressure processing (HPP), and ultrasonic treatment were tested for their ability to activate the defense mechanisms of peanut kernels, thus increasing their bioactive compound content. The results of this study indicate that no RES was detected in ungerminated peanuts, and only 5.58 µg/g of GABA was present, while unstimulated germinated peanuts contained 4.03 µg/g of RES and 258.83 µg/g of GABA. The RES content of the germinated peanuts increased to 13.64 µg/g after soaking in 0.2% phenylalanine solution, whereas a higher GABA content of 651.51 µg/g was observed after the peanuts were soaked in 0.2% glutamate. Soaking peanuts in 5% rice koji produced the highest RES and GABA contents (28.83 µg/g and 506.34 µg/g, respectively). Meanwhile, the RES and GABA contents of HPP-treated germinated peanuts (i.e., treated with HPP at 100 MPa for 10 min) increased to 7.66 µg/g and 497.09 µg/g, respectively, whereas those of ultrasonic-treated germinated peanuts (for 20 min) increased to 13.02 µg/g and 318.71 µg/g, respectively. After soaking peanuts in 0.5% rice koji, followed by HPP treatment at 100 MPa for 10 min, the RES and GABA contents of the germinated peanuts increased to 37.78 µg/g and 1196.98 µg/g, while the RES and GABA contents of the germinated peanuts treated with rice koji followed by ultrasonic treatment for 20 min increased to 46.53 µg/g and 974.52 µg/g, respectively. The flavonoid and polyphenol contents of the germinated peanuts also increased after exposure to various external stimuli, improving their DPPH free radical-scavenging ability and showing the good potential of germinated peanuts as functional products.

First investigation on polyphenols and glycosidic aroma precursors in a spontaneous colour mutant of 'Glera', the principal grape variety of Prosecco sparkling wine.

BACKGROUND: Somatic mutations in Vitis spp. are relatively frequent and can generate new agronomically interesting phenotypes. We report the discovery, genetic and chemical characterization of 'Glera rosa', a mutant for the berry skin colour of 'Glera', the main white cultivar used to produce Prosecco wine. RESULTS: We ascertained the relationship between the skin colour of 'Glera rosa' and the polymorphisms in the Myb-gene transcription factors involved in polyphenol biosynthesis. We established that VvMybA1 was homozygous (VvMybA1a/VvMybA1a) in 'Glera' but heterozygous (VvmybA1a/VvmybA1b) in the 'Glera rosa' mutant. We verified that the VvMybA1a non-functional allele contained Grapevine Retrotransposon 1 (Gret1), while in the VvmybA1b allele Gret1 was missing, and the gene function was partially restored. The effects of mutation on 'Glera rosa' grape metabolites were studied by high-resolution mass spectrometry and gas chromatography/mass spectrometry analysis. Fifteen anthocyanins and five unique flavonols were found in the 'Glera rosa' mutant. The mutation also increased the contents of trans-resveratrol and its derivatives (i.e., piceatannol, E-ε-viniferin, cis- and trans-piceid) and of some flavonols in grape. Finally, the mutation did not significantly affect the typical aroma precursors of Glera grape such as glycosidic monoterpenes, norisoprenoids and benzenoids. CONCLUSION: 'Glera rosa' could be an interesting genetic source for the wine industry to produce Prosecco DOC rosé typology (made by adding up to 15% of 'Pinot Noir'), which was introduced to the market in 2020 with a worldwide massive success. © 2022 Society of Chemical Industry.

Conductive polymer sorbent for extraction and determination of resveratrol and polydatin in Polygonum cuspidatum root samples.

INTRODUCTION: The quantitative analysis of trace resveratrol and polydatin in plant tissues is suitable for elucidation of the compounds' mechanisms of action. OBJECTIVES: The main objective of this work was to develop a feasible and effective sample pretreatment method to measure the concentrations of resveratrol and polydatin in complex samples. METHODOLOGY: A polymer sorbent, poly(2-mercaptobenzimidazole), was electrochemically prepared and utilized for selective extraction, while resveratrol and polydatin were used as target analytes. The sorbent was characterized by cyclic voltammetry, scanning electron microscopy and Fourier transform infrared spectroscopy. After extraction and elution, the analytes were analyzed by a Thermo U3000 HPLC system. Several affecting parameters, including the volume of elution solution, sample pH value, sample flow rate and sample volume, were evaluated and optimized. RESULTS: The proposed method showed good linearity with low limits of detection (from 0.5 to 0.8 ng·mL-1 ) and ideal accuracy with spiked recoveries from 81.30% to 99.16%. A good enrichment factor (more than 200-fold) together with good sensitivity was obtained with this method. Analysis of resveratrol and polydatin in Polygonum cuspidatum samples by this method is efficient. CONCLUSION: The method developed in this work exhibits several significant merits, including easy operation and high extraction efficiency, indicating that electrochemically prepared polymer sorbent is useful for sample pretreatment and analysis of traditional Chinese medicine samples.

Chemometric evaluation of functional components and anti-quorum sensing activity of mulberry leaves from Indian cultivars: a potential contribution to the food industry.

BACKGROUND: Potential use of many native, easily available vegetal materials for human consumption and value addition is not well recognized. Mulberry, being a traditional industrial crop rich in nutrients and nutraceuticals can be of great importance for the food industry. However, mulberry leaves are mainly being utilized in sericulture and are not exploited for their functional components. Thus, the selection of promising mulberry cultivars, rich in bioactive compounds, like resveratrol and 1-deoxynojirimycin, increase their potential use in functional foods. RESULTS: Chlorogenic acid, myricetin and kaempferol were the major polyphenols present in the nine selected cultivars, in the range 0.001-0.086, 0.003-0.079 and 0.003-0.163 g kg-1 fresh weight (FW), respectively. Protocatechuic acid, epicatechin and rutin were predominantly present in cultivars V-1, G-2 and ML (0.103, 0.080 and 0.121 g kg-1 FW, respectively). Similarly, resveratrol and 1-deoxynojirimycin were highest in cultivars ML and K-2 (0.078 and 0.079 g kg-1 FW, respectively). Leaf extracts of cultivars G-2 and ML were able to effectively inhibit the violacein production with 64.08% and 70.04%, respectively at the concentration of 6 mg mL-1 presumably due to a higher content of polyphenols. Chemometric evaluation of chromatographic data showed the intraspecific variability and secondary metabolite co-existence in different cultivars. CONCLUSIONS: Considering phytoconstituents, cultivars G-2, ML, K-2 and V-1 could contribute efficiently to the rational utilization of mulberry in agro-food industries. Furthermore, cultivars G-2 and ML leaves can be a new source of quorum sensing inhibitory agents. © 2021 Society of Chemical Industry.

Colorectal Adenocarcinoma Cell Culture in a Microfluidically Controlled Environment with a Static Molecular Gradient of Polyphenol.

To study the simultaneous effect of the molecular gradient of polyphenols (curcumin, trans-resveratrol, and wogonin) and biological factors released from tumor cells on apoptosis of adjacent cells, a novel microfluidic system was designed and manufactured. The small height/volume of microfluidic culture chambers and static conditions allowed for establishing the local microenvironment and maintaining undisturbed concentration profiles of naturally secreted from cells biochemical factors. In all trials, we observe that these conditions significantly affect cell viability by stimulating cell apoptosis at lower concentrations of polyphenols than in traditional multiwell cultures. The observed difference varied between 20.4-87.8% for curcumin, 11.0-37.5% for resveratrol, and 21.7-62.2% for wogonin. At low concentrations of polyphenols, the proapoptotic substances released from adjacent cells, like protein degradation products, significantly influence cell viability. The mean increase in cell mortality was 38.3% for microfluidic cultures. Our research has also confirmed that the gradient microsystem is useful in routine laboratory tests in the same way as a multiwell plate and may be treated as its replacement in the future. We elaborated the new repetitive procedures for cell culture and tests in static gradient conditions, which may become a gold standard of new drug investigations in the future.

Pterostilbene modifies triglyceride metabolism in hepatic steatosis induced by high-fat high-fructose feeding: a comparison with its analog resveratrol.

The use of phenolic compounds as a new therapeutic approach against NAFLD has emerged recently. In the present study, we aim to study the effect of pterostilbene in the prevention of liver steatosis developed as a consequence of high-fat (saturated) high-fructose feeding, by analysing the changes induced in metabolic pathways involved in triglyceride accumulation. Interestingly, a comparison with the anti-steatotic effect of its parent compound resveratrol will be made for the first time. Rats were distributed into 5 experimental groups and fed either a standard laboratory diet or a high-fat high-fructose diet supplemented with or without pterostilbene (15 or 30 mg per kg per d) or resveratrol (30 mg per kg per d) for 8 weeks. Serum triglyceride, cholesterol, NEFA and transaminase levels were quantified. Liver histological analysis was carried out by haematoxylin-eosin staining. Different pathways involved in liver triglyceride metabolism, including fatty acid synthesis, uptake and oxidation, triglyceride assembly and triglyceride release, were studied. Pterostilbene was shown to partially prevent high-fat high-fructose feeding induced liver steatosis in rats, demonstrating a dose-response pattern. In this dietary model, it acts mainly by reducing de novo lipogenesis and increasing triglyceride assembly and release. Improvement in mitochondrial functionality was also appreciated. At the same dose, the magnitude of pterostilbene and resveratrol induced effects, as well as the involved mechanisms of action, were similar.

Surface plasmon resonance biosensor combined with lentiviral particle stabilization strategy for rapid and specific screening of P-Glycoprotein ligands.

A novel surface plasmon resonance-based P-gp ligand screening system (SPR-PLSS) combined with lentiviral particle (LVP) stabilization strategy was constructed to screen out potential P-gp inhibitors from natural products. Firstly, we constructed LVPs with high and low expression levels of P-gp. The LVPs can ensure the natural conformation of P-gp based on the principle that LVPs germinated from packaging cells will contain cell membrane fragments and P-gp they carry. Then the LVPs with high P-gp expression for active channel and LVPs with low P-gp expression for reference channel were immobilized on CM5 chip respectively. The affinity detection was thus carried out with the signal reduction on the two channels. The P-gp inhibitors, Valspodar (Val) and cyclosporin (CsA), as positive compounds, were detected to characterize the chip's activity, and the KD of Val and CsA were 14.09 µM and 16.41 µM, respectively. Forty compounds from natural product library were screened using the SPR CM5 chip, and magnolol (Mag), honokiol (Hon), and resveratrol (Res) were screened out as potential P-gp ligands, showing a significant response signal. This work presented a novel P-gp ligand screening system based on LVP-immobilized biosensor to rapidly screen out P-gp ligands from natural product library. Compared with traditional cell experiments which the screening time may take up to several days, our method only takes several hours. Furthermore, this study has also provided solid evidences to support that some complicated membrane proteins would apply to the lentivirus-based SPR screening system.

Impact of Climatic Conditions on the Resveratrol Concentration in Blend of Vitis vinifera L. cvs. Barbera and Croatina Grape Wines.

The aim of this work was to investigate the effect of meteorological conditions on resveratrol concentration of red wines produced in Piacenza viticultural region (Italy). In this regard, six representative estates producing Colli Piacentini Gutturnio DOC (a blend of V. vinifera L. cvs. Barbera and Croatina) vintage wines were analysed for trans- and cis-resveratrol over an 8-year period (1998-2005). Grapes were taken from the same vineyard in each estate by using the same enological practices over the entire investigated period. The meteorological conditions corresponding to the production areas were recorded, and bioclimatic indices were calculated as well. Overall, cis-resveratrol concentration was negatively correlated to Huglin index and August mean temperature, whilst positive correlation coefficients were found when considering the Selianinov index and the rainfall of September.