Specific Polyphenols Research Articles

Adherence to UK dietary guidelines is associated with higher dietary intake of total and specific polyphenols compared with a traditional UK diet: further analysis of data from the Cardiovascular risk REduction Study: Supported by an Integrated Dietary Approach (CRESSIDA) randomised controlled trial.

Adherence to dietary guidelines (DG) may result in higher intake of polyphenols via increased consumption of fruits, vegetables and whole grains. We compared polyphenol dietary intake and urinary excretion between two intervention groups in the Cardiovascular risk REduction Study: Supported by an Integrated Dietary Approach study: a 12-week parallel-arm, randomised controlled trial (n 161; sixty-four males, ninety-seven females; aged 40-70 years). One group adhered to UK DG, whereas the other group consumed a representative UK diet (control). We estimated polyphenol dietary intake, using a 4-d food diary (4-DFD) and FFQ, and analysed 24-h polyphenol urinary excretion by liquid chromatography-tandem MS on a subset of participants (n 46 control; n 45 DG). A polyphenol food composition database for 4-DFD analysis was generated using Phenol-Explorer and USDA databases. Total polyphenol intake by 4-DFD at endpoint (geometric means with 95 % CI, adjusted for baseline and sex) was significantly higher in the DG group (1279 mg/d per 10 MJ; 1158, 1412) compared with the control group (1084 mg/d per 10 MJ; 980, 1197). The greater total polyphenol intake in the DG group was attributed to higher intake of anthocyanins, proanthocyanidins and hydroxycinnamic acids, with the primary food sources being fruits, cereal products, nuts and seeds. FFQ estimates of flavonoid intake also detected greater intake in DG compared with the control group. 24-h urinary excretion showed consistency with 4-DFD in their ability to discriminate between dietary intervention groups for six out of ten selected, individual polyphenols. In conclusion, following UK DG increased total polyphenol intake by approximately 20 %, but not all polyphenol subclasses corresponded with this finding.

Wine Polyphenols and Neurodegenerative Diseases: An Update on the Molecular Mechanisms Underpinning Their Protective Effects

Alzheimer’s and Parkinson’s diseases are the most common age-related and predominantly idiopathic neurodegenerative disorders of unknown pathogenesis. Although these diseases differ in their clinical and neuropathological features, they also share some common aetiologies, such as protein aggregation, mitochondrial dysfunction, oxidative stress, and neuroinflammation. Epidemiological, in vitro and in vivo evidences suggest an inverse correlation between wine consumption and the incidence of neurodegenerative disorders. Wine benefits are, in large part, attributable to the intake of specific polyphenols, which mediate cell function under both normal and pathological conditions. In this review, we aim to provide an overview of the role that wine polyphenols play in delaying neurodegenerative disorders. We discuss animal and in vitro studies in support of these actions and we consider how their biological mechanisms at the cellular level may underpin their physiological effects. Together, these data indicate that polyphenols present in wine may hold neuroprotective potential in delaying the onset of neurodegenerative disorders.

Bio-Functional Properties of Bee Pollen: The Case of “Bee Pollen Yoghurt”

The objectives of the present work were: (a) to characterize bee pollen from the region of Epirus in terms of biofunctional activity parameters as assessed by (i) the determination of specific polyphenols using high performance liquid chromatography electrospray ionization mass spectrometry (HPLC/ESI-MS), (ii) antioxidant capacity (DPPH assay), and (iii) total phenolic content (Folin-Ciocalteu assay), and (b) to prepare yoghurts from cow, goat, and sheep milk supplemented with different concentrations of grounded bee pollen (0.5, 1.0, 2.5 and 3.0%, w/v), and study afterwards the trend in antioxidant capacity and total phenolic content along with product’s sensory properties. Results showed that bee pollen ethanolic extracts are a rich source of phytochemicals based on the high total phenolic content and in vitro antioxidant activity that were monitored. The addition of grounded bee pollen in yoghurts resulted in a food matrix of a higher in vitro antioxidant capacity and total phenolic content, whereas it improved the yoghurt’s taste, odour, appearance, and cohesion; the latter indicates its beneficial use as a general food surface and interface material enhancer due to the possible formation of surface/interface active lipid-linked proteins. Based on the present findings, bee pollen yoghurt is proposed as a novel and costless functional food whereas it may comprise a research basis for food or material science in the scientific society of the future. Results were further supported by implementation of advanced chemometric analyses providing a full characterization of the product’s uniqueness.

Investigating the relationship between cell wall polysaccharide composition and the extractability of grape phenolic compounds into Shiraz wines. Part II: Extractability during fermentation into wines made from grapes of different ripeness levels.

This study evaluated the relationship between cell wall breakdown, from Shiraz grapes harvested at three different ripeness levels and the colour and phenolics extracted during alcoholic fermentation into wines. Phenolic differences between the ripeness treatments were minimal after ¼ of the fermentation was completed. However, colour and phenolic content were significantly higher in finished wines made from 25°Brix grapes compared to those from 21°Brix and 23°Brix. Levels of grape cell wall polysaccharide deconstruction during fermentation was a determining correlative factor in relation to phenolic extractability. In this context, the de-pectination observed during ripening was found to enhance this deconstruction or "opening-up" of the grape pomace during fermentation, thus increasing the differential extraction of specific polyphenols, especially polymeric polyphenols, into the wines. Additionally, the degree of cell wall deconstruction seemed to play a role in the possible retention and extraction of specific grape proanthocyanidins, depending on their nature and polymer length.

Prospective Association between Total and Specific Dietary Polyphenol Intakes and Cardiovascular Disease Risk in the Nutrinet-Santé French Cohort.

Background: Epidemiological and experimental evidence support a protective effect of dietary polyphenols on chronic diseases, but high quality longitudinal data are needed, including details on categories of polyphenols. Our objective was to investigate the prospective association between total and individual classes and subclasses of dietary polyphenols and the risk of major cardiovascular disease in the NutriNet-Santé cohort. Methods: A total of 84,158 participants, who completed at least three 24 h dietary records, were included between May 2009 and June 2017. Individual polyphenols intakes were obtained by matching food consumption data from the 24 h dietary records with the Phenol-Explorer polyphenol composition database. Multivariable Cox proportional hazards models were used to characterize the associations between dietary polyphenols and the incidence of cardiovascular diseases, comparing tertile T3 vs. T1 of classes and subclasses of polyphenols. Results: Over a median of 4.9 years of follow-up, 602 major cardiovascular events were diagnosed. Intakes of anthocyanins, catechins, and flavonols were strongly inversely associated with cardiovascular disease risk (anthocyanins: Hazard Ratio (HR)for a 1-point increment of 10 mg/day = 0.98 (0.96–0.99, p = 0.03, HRT3vs.T1 = 0.66 (0.52–0.83), ptrend = 0.0003; catechins: HRfor a 1-point increment of 10 mg/day = 0.98 (0.96–0.99), p = 0.02, HRT3vs.T1 = 0.74 (0.60–0.91), ptrend = 0.004; flavonols: HRfor a 1-point increment of 10 mg/day = 0.94 (0.90–0.99), p = 0.02, HRT3vs.T1 = 0.75 (0.61–0.94), ptrend = 0.006). Intakes of dihydrochalcones, proanthocyaninidins, dihydroflavonols, hydroxybenzoic acids, and stilbenes were also associated with a decrease (13%, 19%, 24%, 24%, and 27%, respectively) in cardiovascular disease risk, when comparing tertile T3 to T1. Conclusions: Higher intakes of polyphenols, especially of anthocyanins, catechins, and flavonols, were associated with a statistically significant decreased cardiovascular disease risk.

Relationship between Mediterranean Dietary Polyphenol Intake and Obesity.

Obesity is a multifactorial and complex disease defined by excess of adipose mass and constitutes a serious health problem. Adipose tissue acts as an endocrine organ secreting a wide range of inflammatory adipocytokines, which leads to systemic inflammation, insulin resistance, and metabolic disorders. The traditional Mediterranean diet is characterized by a high phenolic-rich foods intake, including extra-virgin olive oil, nuts, red wine, vegetables, fruits, legumes, and whole-grain cereals. Evidence for polyphenols’ effect on obesity and weight control in humans is inconsistent and the health effects of polyphenols depend on the amount consumed and their bioavailability. The mechanisms involved in weight loss in which polyphenols may have a role are: activating β-oxidation; a prebiotic effect for gut microbiota; inducing satiety; stimulating energy expenditure by inducing thermogenesis in brown adipose tissue; modulating adipose tissue inhibiting adipocyte differentiation; promoting adipocyte apoptosis and increasing lipolysis. Even though the intake of some specific polyphenols has been associated with body weight changes, there is still no evidence for the effects of total polyphenols or some polyphenol subclasses in humans on adiposity.

The functional potential of immortelle (Helichrysum italicum) based edible films reinforced with proteins and hydrogel particles

Since most studies regarding immortelle (Helichrysum italicum) are focused on the properties and composition of its essential oil, the aim of this study was to develop edible films based on immortelle water extract. Alginate and pectin combined with various proteins served as carriers for the formulation of biodegradable films and hydrogel particles. Films with different biopolymers and incorporated hydrogel particles were prepared by casting method and hydrogel particles were produced by ionic gelation. The bioactive profile (the content of total (TPC) and specific polyphenols, hydroxycinnamic acids (HCAC) and antioxidant capacity (AC)) of the developed matrices was characterized using spectrophotometric methods and high performance liquid chromatography (HPLC). Zeta-potential and rheological properties of alginate- and pectin-based film-forming solutions and physico-chemical (color, particle size, film thickness, dry matter content) and sensory properties of the developed particles and films were evaluated. The highest TPC (31.31 mg GAE/g sample) and HCAC (27.20 mg CAE/g sample) as well as the highest AC (0.15 mmol TE/g sample) was determined in pectin-based films. The addition of proteins decreased the content of the examined bioactive parameters, while the addition of hydrogel particles altered their physico-chemical properties. The obtained results indicate a great application potential of the developed biodegradable matrices.

Differential Modulation of Gene Expression Encoding Hepatic and Renal Xenobiotic Metabolizing Enzymes by an Aspalathin-Enriched Rooibos Extract and Aspalathin.

Modulation of the expression of hepatic and renal genes encoding xenobiotic metabolizing enzymes by an aspalathin-enriched green rooibos (Aspalathus linearis) extract (GRE) was investigated in the liver and kidneys of F344 rats following dietary exposure of 28 d, as well as selected xenobiotic metabolizing genes in rat primary hepatocytes. In the liver, GRE upregulated genes (p < 0.05) encoding aldehyde dehydrogenase, glucose phosphate isomerase, and cytochrome P450 while 17β-hydroxysteroid dehydrogenase 2 (Hsd17β2) was downregulated. In primary hepatocytes, GRE lacked any effect, while aspalathin downregulated Hsd17β2, mimicking the effect of GRE in vivo, and upregulated catechol-O-methyl transferase and marginally (p < 0.1) cytochrome P450 2e1. In the kidneys, GRE upregulated (p < 0.05) genes encoding the phase II xenobiotic metabolism enzymes, glutathione-S-transferase mµ and microsomal glutathione-S-transferase, while downregulating genes encoding the ATP binding cassette transporter, cytochrome P450, gamma glutamyltransferase 1, and N-acetyltransferase 1. Differential modulation of the expression of xenobiotic metabolizing genes in vivo and in vitro by GRE is dose-related, duration of exposure, the tissue type, and interactions between specific polyphenol and/or combinations thereof. Aspalathin is likely to be responsible for the downregulation of estradiol and testosterone catabolism by GRE in the liver. The differential gene expression by GRE in the liver and kidneys could, depending on the duration exposure and dose utilized, determine the safe use of such an extract in humans for specific health and/or disease outcomes.

A prospective evaluation of plasma polyphenol levels and colon cancer risk.

Polyphenols have been shown to exert biological activity in experimental models of colon cancer; however, human data linking specific polyphenols to colon cancer is limited. We assessed the relationship between pre‐diagnostic plasma polyphenols and colon cancer risk in a case–control study nested within the European Prospective Investigation into Cancer and Nutrition study. Using high pressure liquid chromatography coupled to tandem mass spectrometry, we measured concentrations of 35 polyphenols in plasma from 809 incident colon cancer cases and 809 matched controls. We used multivariable adjusted conditional logistic regression models that included established colon cancer risk factors. The false discovery rate (q values) was computed to control for multiple comparisons. All statistical tests were two‐sided. After false discovery rate correction and in continuous log2‐transformed multivariable models, equol (odds ratio [OR] per log2‐value, 0.86, 95% confidence interval [95% CI] = 0.79–0.93; q value = 0.01) and homovanillic acid (OR per log2‐value, 1.46, 95% CI = 1.16–1.84; q value = 0.02) were associated with colon cancer risk. Comparing extreme fifths, equol concentrations were inversely associated with colon cancer risk (OR = 0.61, 95% CI = 0.41–0.91, p trend = 0.003), while homovanillic acid concentrations were positively associated with colon cancer development (OR = 1.72, 95% CI = 1.17–2.53, p trend < 0.0001). No heterogeneity for these associations was observed by sex and across other colon cancer risk factors. The remaining polyphenols were not associated with colon cancer risk. Higher equol concentrations were associated with lower risk, and higher homovanillic acid concentrations were associated with greater risk of colon cancer. These findings support a potential role for specific polyphenols in colon tumorigenesis.

Bioassay-guided purification of Lippia citriodora polyphenols with AMPK modulatory activity

Recently, the relationship between nutrients and health is becoming since natural dietary products as polyphenols are being considered by their potential for the management of several diseases. We aimed to investigate the capacity of Lippia citriodora compounds to modulate AMP-activated protein kinase activity (AMPK) on a hypertrophic adipocyte model. HPLC semi-preparative purification method and reverse phase high performance liquid chromatography coupled to time-of-flight mass detection with electrospray ionization (RP-HPLC-ESI-TOF/MS) were used to obtain de compounds from L. citriodora extract. AMPK activity was measured on the hypertrophic 3T3-L1 adipocyte model by immunofluorescence microscopy. Four compounds of 29 total compounds have been tentatively identified in L. citriodora for the first time by HPLC-ESI-TOF-MS. Phenylpropanoids (verbascoside), iridoids (gardoside) and flavonoids (luteolin-7-diglucoronide) were the best candidates to account for activating AMPK capacity. The combination of specific polyphenols from L. citriodora, which showed strong activating AMPK capacity, could be an alternative in the management of obesity-associated diseases.

Impact of tart cherries polyphenols on the human gut microbiota and phenolic metabolites in vitro and in vivo

Tart cherries have been reported to exert potential health benefits attributed to their specific and abundant polyphenol content. However, there is a need to study the impact and fate of tart cherries polyphenols in the gut microbiota. Here, tart cherries, pure polyphenols (and apricots) were submitted to in vitro bacterial fermentation assays and assessed through 16S rRNA gene sequence sequencing and metabolomics. A short-term (5 days, 8 oz. daily) human dietary intervention study was also conducted for microbiota analyses.Tart cherry concentrate juices were found to contain expected abundances of anthocyanins (cyanidin-glycosylrutinoside) and flavonoids (quercetin-rutinoside) and high amounts of chlorogenic and neochlorogenic acids. Targeted metabolomics confirmed that gut microbes were able to degrade those polyphenols mainly to 4-hydroxyphenylpropionic acids and to lower amounts of epicatechin and 4-hydroxybenzoic acids. Tart cherries were found to induce a large increase of Bacteroides in vitro, likely due to the input of polysaccharides, but prebiotic effect was also suggested by Bifidobacterium increase from chlorogenic acid. In the human study, two distinct and inverse responses to tart cherry consumption were associated with initial levels of Bacteroides. High-Bacteroides individuals responded with a decrease in Bacteroides and Bifidobacterium, and an increase of Lachnospiraceae, Ruminococcus and Collinsella. Low-Bacteroides individuals responded with an increase in Bacteroides or Prevotella and Bifidobacterium, and a decrease of Lachnospiraceae, Ruminococcus and Collinsella. These data confirm that gut microbiota metabolism, in particular the potential existence of different metabotypes, needs to be considered in studies attempting to link tart cherries consumption and health.

Antioxidant activity and contents of leaf extracts obtained from Dendropanax morbifera LEV are dependent on the collecting season and extraction conditions.

This study compared the antioxidant activity of extracts from Dendropanax morbifera (D. morbifera) Levillis leaves. The concentrations of flavonoids and polyphenols were measured in extracts of D. morbifera leaves. The antioxidant activities were examined by ABTS and DPPH radical scavenging activity and ferric reducing antioxidant power (FRAP). Total flavonoid and polyphenol contents, and FRAP were highest in the 30% ethanol extract collected in May. The ABTS and DPPH radical scavenging activities were the highest in the 60% ethanol extract harvested in May. For investigating the relationship between antioxidant activity and specific polyphenols, rutin and chlorogenic acid of the polyphenol component were quantified by LC-MS/MS analysis. The concentrations of them were highest in the 60% ethanol extract collected in May, and showed positive correlations with antioxidant activities. The optimal extraction conditions to yield the most effective antioxidant activity were obtained using a 60% ethanol extraction solvent with samples collected in May.

Optimization of spray drying microencapsulation of olive pomace polyphenols using Response Surface Methodology and Artificial Neural Network

This study was performed to determine the optimum conditions for spray drying microencapsulation of olive pomace extract, in order to stabilize its phenolic compounds using maltodextrin as carrier material. To this purpose, a comparison optimization study was performed using Response Surface Methodology or Artificial Neural Network, which revealed better prediction accuracy of the former. Maltodextrin concentrations (100–500 g/L), inlet-drying air temperatures (130–160 °C), feed flowrates (5.0–10.0 mL/min), and drying compressed air flowrates (20–32 m3 h−1) were tested as the independent variables according to a Central Composite Face Centered design, and the results of microencapsulation yield, moisture content, water solubility, specific total polyphenol content, specific antioxidant activity and encapsulation efficiency were elaborated. Under optimal conditions, these responses varied in the ranges 65–82%, 9–14 g/100 g, 64–65%, 38–52 mgCAE gDM−1, 230–487 μgTrolox gDM−1 and 85–92%, respectively. The same optimization regions for operative parameters were obtained using Response Surface Methodology or Artificial Neural Network. The results demonstrated that maltodextrin-based microcapsules containing olive pomace extract can effectively be produced by spray drying with good stability under storage conditions, and suggest that their remarkable antioxidant activity may be exploited to improve the properties of functional foods or pharmaceutical products.

The Potential of Combined Emulsification and Spray Drying Techniques for Encapsulation of Polyphenols from Rosemary (Rosmarinus officinalis L.) Leaves.

SUMMARYThe present study evaluates the potential of encapsulation of polyphenolic antioxidants from rosemary (Rosmarinus officinalis L.) leaves by combining emulsification and spray drying techniques. To stabilize the emulsions and prepare samples suitable for use in dry products, double emulsions encapsulating rosemary polyphenolic extract and containing polyglycerol polyricinoleate (4%), whey protein isolates (2 and 4%) as emulsifiers, and maltodextrins (MDE 10 and 21) as enhancing coatings were subjected to spray drying. The obtained results show insignificant (p>0.05) effect of used maltodextrin type and protein content on mean particle size of double emulsions containing rosemary polyphenols. Morphology analyses showed that double emulsions were successfully prepared, spherical microcapsules were obtained after spray drying of double emulsions and double emulsion form was still preserved after rehydration of spray-dried microcapsules. Regardless of used maltodextrins, significantly (p>0.05) higher encapsulation efficiencies (EE) of total polyphenols (39.57 and 42.83%) in rehydrated samples were achieved when higher protein content (4% whey protein isolate) was used, indicating the major impact of protein content on EE of rosemary polyphenols. Also, using HPLC analysis, rosmarinic and caffeic acids, apigenin and luteolin derivatives were detected among specific polyphenols, where rosmarinic acid had notable encapsulation efficiency ranging from 62.15 to 67.43%. In this way, the obtained microcapsules encapsulating rosemary polyphenols could be easily blended with various dry mixtures, and serve for delivery in different functional products.

Epigenetic modifications by polyphenolic compounds alter gene expression in the hippocampus.

ABSTRACTIn this study, we developed an experimental protocol leveraging enhanced reduced representation bisulphite sequencing to investigate methylation and gene expression patterns in the hippocampus in response to polyphenolic compounds. We report that the administration of a standardized bioavailable polyphenolic preparation (BDPP) differentially influences methylated cytosine patterns in introns, UTR and exons in hippocampal genes. We subsequently established that dietary BDPP-mediated changes in methylation influenced the transcriptional pattern of select genes that are involved in synaptic plasticity. In addition, we showed dietary BDPP mediated changes in the transcriptional pattern of genes associated with epigenetic modifications, including members of the DNA methyl transferase family (DNMTs) and the Ten-eleven translocation methylcytosine dioxygenases family (TETs). We then identified the specific brain bioavailable polyphenols effective in regulating the transcription of DNMTs, TETs and a subset of differentially methylated synaptic plasticity-associated genes. The study implicates the regulation of gene expression in the hippocampus by epigenetic mechanisms as a novel therapeutic target for dietary polyphenols.

Total Phenolic Content and Antioxidant Capacity of Selected Canned Fruits

Fruits are high in polyphenols which are compounds associated with the protection against diseases such as diabetes and cancer. However, food processing including canning can leads to the loss of polyphenol in the fruits. Thus, the aim of this study was to evaluate the total phenolic content (TPC) and antioxidant capacity of canned fruits commercially available in the local supermarkets in Malaysia. The TPC was determined by using Folin-Ciocalteu method while the antioxidant capacity was evaluated by using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH assay) and Ferric Reducing Antioxidant Power (FRAP assay). Five types of different canned fruits with the total of 21 samples including longan, lychee, rambutan, pineapple and orange were selected for the analysis. The samples were analyzed in two forms which were, the homogenized (fruits and syrup) and syrup samples. Canned pineapples have the highest TPC for both homogenized (95.16±30.16 mg GAE/100 g) and syrup sample (108.62±33.88 mg GAE/100 g). For antioxidant capacity, canned pineapple also had the highest value for the homogenized sample (41.79±4.20 umol TE/100 g) while lychee was the highest (46.84±12.81 umol TE/100 g) for syrup sample assessed by DPPH assay. For FRAP assay, lychee was highest in antioxidant capacity for both homogenized sample (40.61±10.55 umol TE/100 g) and syrup sample (33.58±7.56 umol TE/100 g). A positive and significant (P &lt; 0.001) correlation was found between TPC and antioxidant capacity (DPPH and FRAP). In conclusion, canned pineapple and lychee were the highest sources of polyphenol as compared to other types of canned fruits. Further investigation is warranted to determine the specific polyphenol present in the canned fruits.

Phlorotannin-rich fraction from Ishige foliacea brown seaweed prevents the scopolamine-induced memory impairment via regulation of ERK-CREB-BDNF pathway

Ishige foliacea, a species of edible brown algae, contains specific polyphenols called phlorotannins, which have antioxidant, anti-inflammatory, and anticancer properties. We hypothesized that the phlorotannin-rich fraction of I. foliacea (PRFI) is neuroprotective. We investigated the effects of PRFI on scopolamine-induced memory impairment in mice. PRFI (50 or 100 mg/kg) supplementation for 6 weeks improved scopolamine-induced memory impairment symptoms in the Morris water maze and passive avoidance tests. PRFI reduced acetylcholinesterase activity in the brain and significantly decreased lipid peroxidation levels, but increased glutathione levels and superoxide dismutase activity. Additionally, PRFI up-regulated the expression levels of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B, and phosphorylated extracellular signal-regulated kinase (ERK) and cyclic AMP-response element-binding protein (CREB), which are involved in neuroplasticity in the cerebral cortex and hippocampus. Our results suggest that PRFI prevents scopolamine-induced memory impairment, possibly through oxidative scavenging and ERK-CREB-BDNF pathway regulation.

Synergistic Effect of the Combination of Polyphenols with Gemcitabineon Pancreatic Cancer Cell line AsPC-1

In our diet, polyphenols are micronutrients with an important role in the prevention of degenerative diseases such as cancer and cardiovascular diseases. Particularly, Pancreatic cancer is one of the most aggressive cancers, with only about 5% of patients surviving 5 years past the initial diagnosis. Despite advances with current chemotherapy combinations, overall survival outcomes are still require novel therapeutic approaches. Here, we examined the efficacy of combined treatments of polyphenols and gemcitabine the standard of treatment for patients with metastatic pancreatic cancer in human pancreatic cancer cells. For that purpose, the pro-apoptic effects of gemcitabine were studied on the human pancreatic cell line AsPC1 in presence or absence of several polyphenols, in order to evaluate if they latter are able to potentialize gemcitabine cytotoxicity. Our study aims to investigate the implication of MDR1 (multidrug transporter)in resistance to gemcitabine and if the studied polyphenol could target this drug efflux pump in AsPC-1 cells by flow cytometric analysis. We observed that 5µg/ml gemcitabine in combination with 15 µg/ml of selected polyphenol (Catechin, Quercetin, Bergamottin, Rhamnetin) was more effective than gemcitabine alone, by increased in the percentage of dead cells up to 60%. Morever our results demonstrated that some polyphenols (Quercetin) inhibit the efflux activity of MDR1. Our study in vitro suggests therefore that chemotherapy with gemcitabine might be significantly increased upon combination with specific polyphenol. In conclusion, polyphenols may be promising agents for novel combination therapy since they potentialize the cytotoxic activity of gemcitabine to eradicate pancreatic cancer and therefore the cellular resistance.

A hydrocolloid based biorefinery approach to the valorisation of mango peel waste

An environment-friendly hydrothermal process was developed to extract pectin from a horticultural waste, namely mango peels, at a reasonable temperature and pressure. High average yields of pectin (15.7%, 27.2%) were obtained from the two mango cultivars namely, Calypso (Australian) and Totapuri (Indian). The physico-chemical characteristics were determined in terms of the degree of esterification (77–89%), molecular weights (Mw) (49,742–49,862 Da), FTIR and gelling tests. The spent liquor was hydrolysed to recover the specific polyphenols and sugars. The polyphenols in the hydrolysed liquid were quantified as gallic acid (525.1–1405.6 mg/l), mangiferin (7.8–162.2 mg/l), quercetin (40.6–49.2 mg/l) and ellagic acid (38.8–69.3 mg/l). The solid residue obtained as a solid co-product after pectin extraction was found to be rich in cellulose (38%) and lignin (16%). In this paper, an attempt has been made to address the challenges of the extraction of pectin from mango peels, in a conventional process. It was demonstrated that mango peels may be a promising unconventional source for recovery of food-grade quality pectin. Considerable efforts, which were earlier expended in the processing, were reduced when recovery of other food-grade co-products was integrated with the process of hydrocolloid extraction.

Total and specific dietary polyphenol intakes and 6-year anthropometric changes in a middle-aged general population cohort.

Dietary polyphenols are suggested antiobesogenic agents. Prospective evidence in general population of an association between polyphenol intakes and anthropometry is lacking. To assess the associations between dietary polyphenol intakes and changes in body mass index (BMI) and waist circumference (WC) over a 6-year period. Individual intakes of 264 different polyphenols (mg day-1) were estimated using the Phenol-Explorer database and the mean of 6-17 24-h dietary records collected in 1994-1996. BMI in kg m-2 and WC in cm were measured in 1995-1996, 1998-1999 and 2001-2002. Linear mixed-effect models allowed for the assessment of longitudinal associations between energy-adjusted quartiles of total polyphenol intake as well as intake of 15 polyphenol classes and changes of these respective polyphenol classes in anthropometry over the 6 years of follow-up. Adjustment variables included sex, age, socio-economic status, lifestyle, dietary intakes and health status. Participants in the highest quartile of intake of flavanones (BMI change: -0.28 (-0.43; -0.13), P=0.009), flavones (BMI change: -0.29 (-0.44; -0.14), P=0.008) and lignans (BMI change: -0.28 (-1.63; -0.09), P=0.01) experienced a less notable increase in BMI over time compared with their counterparts in the bottom quartile of intake of the respective polyphenol classes. Participants in the highest quartile of intake of flavanones (WC change: -1.39 (-2.02; -0.92), P=0.001), flavones (WC change: -1.57 (-2.32; -0.92), P=0.001), hydroxycinnamic acids (WC change: -1.27 (-1.92; -0.63), P=0.01), lignans (WC change: -1.16 (-1.80; -0.51), P=0.006) and total polyphenol intake (WC change: -1.39 (-2.05; -0.74), P=0.001) experienced a less notable increase in WC over time compared with their counterparts in the bottom quartile of intake of the respective polyphenols. Dietary polyphenol intakes may help reduce weight gain over time in the general population. This could have important public health implications because moderate increases in BMI and WC over time have been shown to increase disease risk.