Catechins and procyanidins in Mediterranean diets

The Effect of Ripening Stages on the Accumulation of Polyphenols and Antioxidant Activity of the Fruit Extracts of Solanum Species

The aim of the research was to evaluate the influence of the ripening stage on the accumulation of polyphenols and antioxidant activity in fruits of Solanum species. The experiment included two factors: I-four different Solanum species (S. melanocerasum, S. nigrum, S. villosum, and S. retroflexum) and II-three ripening stages. High-performance liquid chromatography (HPLC) was used to analyze the individual phenolic compounds (flavonoids and phenolic acids), and the spectrophotometric method was applied to determine antioxidant activity. The results revealed that the accumulation of polyphenols and antioxidant activity in fruits of Solanum species depends on the stage of ripening and species. All studied Solanum species fruits had the highest content of total phenolic acid at ripening stage III and the greatest antioxidant activity at ripening stage I. Fully ripe fruits of S. melanocerasum contained significantly more total flavonoids, whereas S. nigrum contained significantly more total phenolic acids than other investigated Solanum species fruits. The significantly highest antioxidant activity was found in S. melanocerasum fruits at ripening stage I.

Potential of traditional Chilean blood-fleshed peach to support livelihood opportunities in local agriculture

The blood-flesh peach or vineyard peach is an older heritage cultivar with juicy red-flesh and tart-sweet flavor. They are popular in France, where more than 200 years ago wine growers used to plant them on the vineyards as biological markers to detect the presence of powdery mildew. It is present in countries such as China, Italy, New Zealand, Australia and USA however, it remains a very rare variety worldwide. In Chile, the blood-flesh peach has a centenary presence in rural orchards where is called “Durazno Betarraga.” Reproduced by seeds, it has pass through generations of family farmers and has been adapted to local environmental conditions. This red-flesh peach is a local variety considered part of their traditional diets, however, cultural changes in food consumption, short postharvest life and water scarcity due to climate change are threatening its conservation. One of the objectives of the International Year of Fruits and Vegetables, as defined by the FAO, is to integrate small holders and family farmers into value chains for sustainable production and consumption of fruits and vegetables recognizing the contributions of farmer's landraces to their food security, nutrition, livelihoods and income. To promote this objective, we present the work we have been carry out for several years with a farming community. We have conducted ethnographic research to provide a qualitative description of the agricultural value of the blood peach in a limited territory of the Maule Region defined as the study area. For the quantitative section of our research we analyzed the antioxidant capacity (ORAC) and total polyphenol content and compared them with those of other fruits. To gather information on the presence of the blood-fleshed peach in other regions of Chile, we used a citizen science approach through social networks. We propose that this local variety is an innovative raw material to develop healthy fruit-based food, thus encouraging its conservation and consumption with a positive social and economic impact for the community and the local food system.

Polyphenols–Gut–Heart: An Impactful Relationship to Improve Cardiovascular Diseases

A healthy gut provides the perfect habitat for trillions of bacteria, called the intestinal microbiota, which is greatly responsive to the long-term diet; it exists in a symbiotic relationship with the host and provides circulating metabolites, hormones, and cytokines necessary for human metabolism. The gut–heart axis is a novel emerging concept based on the accumulating evidence that a perturbed gut microbiota, called dysbiosis, plays a role as a risk factor in the pathogenesis of cardiovascular disease. Consequently, recovery of the gut microbiota composition and function could represent a potential new avenue for improving patient outcomes. Despite their low absorption, preclinical evidence indicates that polyphenols and their metabolites are transformed by intestinal bacteria and halt detrimental microbes’ colonization in the host. Moreover, their metabolites are potentially effective in human health due to antioxidant, anti-inflammatory, and anti-cancer effects. The aim of this review is to provide an overview of the causal role of gut dysbiosis in the pathogenesis of atherosclerosis, hypertension, and heart failure; to discuss the beneficial effects of polyphenols on the intestinal microbiota, and to hypothesize polyphenols or their derivatives as an opportunity to prevent and treat cardiovascular diseases by shaping gut eubiosis.

Current Perspective on the Natural Compounds and Drug Delivery Techniques in Glioblastoma Multiforme

Simple Summary

Glioblastoma multiforme (GBM) is one of the belligerent neoplasia that metastasize to other brain regions and invade nearby healthy tissues. However, the treatments available are associated with some limitations, such as high variations in solid tumors and deregulation of multiple cellular pathways. The heterogeneity of the GBM tumor and its aggressive infiltration into the nearby tissues makes it difficult to treat. Hence, the development of multimodality therapy that can be more effective, novel, with fewer side effects, improving the prognosis for GBM is highly desired. This review evaluated the use of natural phytoconstituents as an alternative for the development of a new therapeutic strategy. The key aspects of GBM and the potential of drug delivery techniques were also assessed, for tumor site delivery with limited side-effects. These efforts will help to provide better therapeutic options to combat GBM in future.

Abstract

Glioblastoma multiforme (GBM) is one of the debilitating brain tumors, being associated with extremely poor prognosis and short median patient survival. GBM is associated with complex pathogenesis with alterations in various cellular signaling events, that participate in cell proliferation and survival. The impairment in cellular redox pathways leads to tumorigenesis. The current standard pharmacological regimen available for glioblastomas, such as radiotherapy and surgical resection following treatment with chemotherapeutic drug temozolomide, remains fatal, due to drug resistance, metastasis and tumor recurrence. Thus, the demand for an effective therapeutic strategy for GBM remains elusive. Hopefully, novel products from natural compounds are suggested as possible solutions. They protect glial cells by reducing oxidative stress and neuroinflammation, inhibiting proliferation, inducing apoptosis, inhibiting pro-oncogene events and intensifying the potent anti-tumor therapies. Targeting aberrant cellular pathways in the amelioration of GBM could promote the development of new therapeutic options that improve patient quality of life and extend survival. Consequently, our review emphasizes several natural compounds in GBM treatment. We also assessed the potential of drug delivery techniques such as nanoparticles, Gliadel wafers and drug delivery using cellular carriers which could lead to a novel path for the obliteration of GBM.

Changes in arterial blood pressure caused by long-term administration of grape seed proanthocyanidins in rats with established hypertension

The development of hypertension (HTN) in cafeteria (CAF) diet-fed rats was demonstrated to be attenuated after grape seed proanthocyanidin extract (GSPE) administration. However, the long-term antihypertensive effect of GSPE in animals with established HTN has not been investigated. Thus, the aim of this study was to evaluate if GSPE shows a blood pressure-lowering effect in hypertensive rats after its administration for 3 weeks. Wistar rats were fed a standard or CAF diet for 12 weeks, and during the last 3 weeks, animals were administered vehicle, captopril or a low dose of GSPE (25 mg per kg body weight, bw). Both systolic and diastolic blood pressure (SBP and DBP) were monitored weekly. The liver reduced glutathione (GSH) levels, plasma angiotensin converting enzyme activity and endothelial gene expression of eNOS, KLF-2, Sirt-1, NOX4 and ET-1 were studied at the end-point. The results demonstrated that 3 weeks of CAF diet administration with 25 mg per kg bw GSPE significantly reduced SBP and DBP in hypertensive rats. GSPE induced the upregulation of Sirt-1 gene expression and downregulated the vasoconstrictor ET-1, suggesting the vasoprotective effect of GSPE and increased the antioxidant GSH activity. The administration of 25 mg per kg bw GSPE for 3 weeks significantly reduced BP in CAF diet fed animals with established HTN.

Anthocyanins and catechins in the berries of new strawberry cultivars grown in the conditions of the Orel region

The results of the study of 20 new strawberry cultivars grown in the conditions of the Central part of Russia (Orel region), according to the content of anthocyanins, catechins and the total number of polyphenols in berries, are presented. Anthocyanins and catechins are representatives of the main group of phenolic compounds, flavonoids that have a therapeutic and preventive effect on the human body. The purpose of the research is to identify the best genotypes for breeding for an improved chemical composition of berries. The determination of phenolic compounds was carried out by the photometric method. The content of anthocyanins in strawberries varied depending on the cultivar to an average degree (V=16.3%) and amounted to 51.1±1.9 mg/100 g with a range of variation from 40.1 to 70.2 mg/100 g. A high content of anthocyanins (mg/100 g) was observed in Rusich (70.2), Solovushka (64.2), Darselect (62.5), Tsaritsa (59.5), Rubino civ (57.9), Sonata (55.4), Alpha (54.5), Honeoye (51.8). The average content of catechins in the berries of the studied group of cultivars also changed to an average degree (V=22.2%) from 71.4 to 174.6 mg/100 g with an average c value of 124.9±6.2 mg/100 g. The high content of catechins in berries was found in Rusich (136,2), Clery (132,0), Rubino civ (137,4), Sara (137,7), Vima Kimberly (139,5), Dezy (152,5), Sonata (164,9), Solovushka (168,2) and Alpha (174,6). There was no correlation between the accumulation of anthocyanins and catechins in strawberries (r=+0.149). According to the total number of polyphenols (more than 500 mg/100 g) in the berries, Alpha, Rusich, Solovushka, Dezy and Rubino civ are distinguished.

Antioxidant Effect of Flavonoids Present in Euterpe oleracea Martius and Neurodegenerative Diseases: A Literature Review

INTRODUCTION

Neurodegenerative diseases (NDDs) are progressive, directly affecting the central nervous system (CNS), the most common and recurrent are Alzheimer's disease (AD) and Parkinson's disease (PD). One factor frequently mentioned in the etiology of NDDs is the generation of free radicals and oxidative stress, producing cellular damages. Studies have shown that the consumption of foods rich in polyphenols, especially those of the flavonoid class, has been related to the low risk in the development of several diseases. Due to the antioxidant properties present in the food, a fruit that has been gaining prominence among these foods is the Euterpe oleracea Mart. (açaí), because it presents in its composition significant amounts of a subclass of the flavonoids, the anthocyanins.

METHODS

In the case review, the authors receive a basic background on the most common NDDs, oxidative stress and antioxidants. In addition, revisiting the various studies related to NDDs, including flavonoids and consumption of açaí.

RESULTS

Detailed analysis of the recently reported case studies reveal that dietary consumption of flavonoid-rich foods, such as açaí fruits, suggests the efficacy to attenuate neurodegeneration and prevent or reverse the age-dependent deterioration of cognitive function.

CONCLUSION

This systematic review points out that flavonoids presenting in açaí have the potential for the treatment of diseases such as PD and AD and are candidates for drugs in future clinical research. However, there is a need for in vitro and in vivo studies with polyphenol that prove and ratify the therapeutic potential of this fruit for several NDDs.

Procyanidins attenuate neuropathic pain by suppressing matrix metalloproteinase-9/2

Background

Management of neuropathic pain is a real clinical challenge. Despite intense investigation, the mechanisms of neuropathic pain remain substantially unidentified. Matrix metalloproteinase (MMP)-9 and MMP-2 have been reported to contribute to the development and maintenance of neuropathic pain. Therefore, inhibition of MMP-9/2 may provide a novel therapeutic approach for the treatment of neuropathic pain. In this study, we aim to investigate the effect of procyanidins (PC), clinically used health product, on MMP-9/2 in neuropathic pain.

Methods

The nociception was assessed by measuring the incidence of foot withdrawal in response to mechanical indentation in mice. Cell signaling was assayed using gelatin zymography, western blotting, and immunohistochemistry. The BV2 cells were cultured to investigate the effects of PC on microglia.

Results

Both in vitro and in vivo administration of PC significantly suppresses the activity of MMP-9/2. Oral administration of PC relieves neuropathic pain behaviors induced by chronic constriction sciatic nerve injury (CCI) in mice. Additionally, PC blocks the maturation of interleukin-1β, which is a critical substrate of MMPs, and markedly suppresses CCI-induced MAPK phosphorylation and neuronal and microglia activation, including the reduced phosphorylation of protein kinase C γ and NMDAR1. Furthermore, PC decreases the phosphorylation of p38 mitogen-activated protein kinase and inhibits the translocation of nuclear factor-κB (NF-κB) in microglia.

Conclusions

PC is an effective and safe approach to alleviate neuropathic pain via a powerful inhibition on the activation of MMP-9/2.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1182-9) contains supplementary material, which is available to authorized users.

Phenolic Compounds as Nutraceuticals or Functional Food Ingredients

BACKGROUND

Nowadays, the functional foods represent one the most promising, interesting and innovative areas in the food industry. Various components are being added to foods in order to render them functional.

METHODS

One example of these components are plant naturally occurring phenolic compounds, which are associated with a high antioxidant capacity and thus with benefits in relation to human health.

RESULTS

However, despite the huge number of scientific studies and patents on this topic and their natural presence in foods, namely in the ones from plant origin, there are still few marketable products enriched with these compounds. The commercialization of this type of functional products needs to go through various regulations, proving that they are safe and present the ascribed health benefits, conquering the target audience. In this review the growing interest of industry and consumers' appetence for functional foods and nutraceuticals is highlighted, focusing especially on phenolic compounds.

CONCLUSION

Although several published works show the multitude of bioactive properties of these compounds, ensuring their use as bioactive ingredients in food, they present inherent stability issues needing to be solved. However, considerable research is presently ongoing to overcome this problem, making viable the development of new products to be launched in the market.

Chemical Composition and Lipid Fraction Characteristics of Aleppo Pine (Pinus halepensis Mill.) Seeds Cultivated in Tunisia

The proximate composition of Aleppo pine ( Pinus halepensis Mill.) seeds cultivated in Bizerta (Tunisia) were investigated for their fatty acid composition, and their thermal and physical properties of lipid fraction. The proximate analysis of pine seeds showed the following composition (on a dry-weight basis): protein 22.7%, oil 43.3%, ash 8.3% and total carbohydrate 25.7%. Potassium, magnesium and calcium were the predominant mineral elements present in the seeds and reached, together, about 1%. Oleic and linoleic acids were the major unsaturated fatty acids (27.3 and 48.8%, respectively), while the main saturated one was palmitic acid (8.75%). Myristic, myristoleic, palmitoleic, margaric, margaroleic, stearic, linolenic, arachidic, eicosenoic, eicosadienoic, eicosatrienoic, behenic and lignoceric acids were also detected. Thermal profile of Pinus halepensis Mill. seed oil, determined by its DSC melting curve, showed that the entire liquefaction of the Aleppo pine seed oil occurs at 8°C. CieLab colour parameters ( L*, a*, b*), oxidative stability by Rancimat test and viscosity were also determined. Physico-chemical properties of the oil include: saponification number 190, peroxide value 3.18, iodine index 117, and a low acidity of 0.61%. Results suggested that the production of oil from Pinus halepensis seeds could provide a potential use in food, pharmaceutical, cosmetics and other non-food industries.

Z-Isomers of (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=OH. Conformational properties, electronic structure and aqueous solvent effects

Procyanidins are highly hydroxylated polymers known as antioxidant compounds, thereby exhibiting beneficial effects. These compounds are protective agents against oxidative stress and the damage induced by free radicals in membranes and nucleic acids. This paper describes a study of the conformational space of (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=OH as part of a larger study of similar structures with different substitutions. The relationships between aqueous solution-vacuum variations of some properties were studied, as well as the stabilization and reactivity of (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=H, R'=H, R=OH, R'=R=OH, and (+)-catechin. The variations in geometric parameters and electronic properties due to conformational changes, as well as the effects of substituents and polar solvents, were evaluated and analyzed. Bader's theory of atoms in molecules was applied to characterize intramolecular interactions, along with a natural bond orbital analysis for each conformer described. The molecular electrostatic potential was rationalized by charge delocalization mechanisms and interatomic intramolecular interactions, relating them to the structural changes and topological properties of the electron charge density. Molecular polarizability and permanent electric dipole moment values were estimated. The results show the importance of a knowledge of the conformational space, and values for each conformer. Based on our previous results, we showed the existence of electron charge delocalization mechanisms acting cooperatively as "delocalization routes", showing interactions between different rings not even sharing the same plane. These "delocalization routes" were more effective for (4α→6″, 2α→O→1″)-phenylflavan substituted with R'=R=OH than for (+)-catechin, and are proposed as adding insight into the structure-antioxidant activity relationship of flavans.

Procyanidins alleviates morphine tolerance by inhibiting activation of NLRP3 inflammasome in microglia

Background

The development of antinociceptive tolerance following repetitive administration of opioid analgesics significantly hinders their clinical use. Evidence has accumulated indicating that microglia within the spinal cord plays a critical role in morphine tolerance. The inhibitor of microglia is effective to attenuate the tolerance; however, the mechanism is not fully understood. Our present study investigated the effects and possible mechanism of a natural product procyanidins in improving morphine tolerance via its specific inhibition on NOD-like receptor protein3 (NLRP3) inflammasome in microglia.

Methods

CD-1 mice were used for tail-flick test to evaluate the degree of pain. The microglial cell line BV-2 was used to investigate the effects and the mechanism of procyanidins. Reactive oxygen species (ROS) produced from BV-2 cells was evaluated by flow cytometry. Cell signaling was measured by western blot assay and immunofluorescence assay.

Results

Co-administration of procyanidins with morphine potentiated its antinociception effect and attenuated the development of acute and chronic morphine tolerance. Procyanidins also inhibited morphine-induced increase of interleukin-1β and activation of NOD-like receptor protein3 (NLRP3) inflammasome. Furthermore, procyanidins decreased the phosphorylation of p38 mitogen-activated protein kinase, inhibited the translocation of nuclear factor-κB (NF-κB), and suppressed the level of reactive oxygen species in microglia.

Conclusions

Procyanidins suppresses morphine-induced activation of NLRP3 inflammasome and inflammatory responses in microglia, and thus resulting in significant attenuation of morphine antinociceptive tolerance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0520-z) contains supplementary material, which is available to authorized users.

Effects of Flavonoids from Food and Dietary Supplements on Glial and Glioblastoma Multiforme Cells

Quercetin, catechins and proanthocyanidins are flavonoids that are prominently featured in foodstuffs and dietary supplements, and may possess anti-carcinogenic activity. Glioblastoma multiforme is the most dangerous form of glioma, a malignancy of the brain connective tissue. This review assesses molecular structures of these flavonoids, their importance as components of diet and dietary supplements, their bioavailability and ability to cross the blood-brain barrier, their reported beneficial health effects, and their effects on non-malignant glial as well as glioblastoma tumor cells. The reviewed flavonoids appear to protect glial cells via reduction of oxidative stress, while some also attenuate glutamate-induced excitotoxicity and reduce neuroinflammation. Most of the reviewed flavonoids inhibit proliferation of glioblastoma cells and induce their death. Moreover, some of them inhibit pro-oncogene signaling pathways and intensify the effect of conventional anti-cancer therapies. However, most of these anti-glioblastoma effects have only been observed in vitro or in animal models. Due to limited ability of the reviewed flavonoids to access the brain, their normal dietary intake is likely insufficient to produce significant anti-cancer effects in this organ, and supplementation is needed.

Improving the estimation of flavonoid intake for study of health outcomes

Imprecision in estimating intakes of non-nutrient bioactive compounds such as flavonoids is a challenge in epidemiologic studies of health outcomes. The sources of this imprecision, using flavonoids as an example, include the variability of bioactive compounds in foods due to differences in growing conditions and processing, the challenges in laboratory quantification of flavonoids in foods, the incompleteness of flavonoid food composition tables, and the lack of adequate dietary assessment instruments. Steps to improve databases of bioactive compounds and to increase the accuracy and precision of the estimation of bioactive compound intakes in studies of health benefits and outcomes are suggested.

Comparative biokinetics and metabolism of pure monomeric, dimeric, and polymeric flavan-3-ols: a randomized cross-over study in humans

SCOPE

Flavan-3-ols are abundant polyphenols in human nutrition and are associated with beneficial health effects. The aim of this study was to comparatively investigate the metabolic fate of (-)-epicatechin, procyanidin B1, and polymeric procyanidins in a randomized cross-over study in humans.

METHODS AND RESULTS

Parent compounds, conjugates, and microbial metabolites were determined in plasma, urine, and faeces by HPLC-MS and GC-MS/MS. Glucuronidated, sulfated, and methylated (-)-epicatechin and 5-(3',4'-dihydroxyphenyl)-valerolactone were the dominant metabolites in blood and urine. In addition, minor amounts of procyanidin B1 and 4-hydroxy-5-(3',4'-dihydroxyphenyl)valeric acid and their conjugated metabolites were detected. The formation of 5-(3',4'-dihydroxyphenyl)-valerolactone and 4-hydroxy-5-(3',4'-dihydroxyphenyl)valeric acid varied largely between individuals as well as with the degree of polymerization of flavan-3-ols. Monomer units were not detectable in plasma or urine after procyanidin B1 and polymeric procyanidin intake. No correlation was found between the intake of flavan-3-ols and the occurrence of phenolic acids in blood and urine or the phenolic compound profiles in faeces.

CONCLUSION

In addition to conjugated metabolites derived from the absorption of monomeric flavan-3-ols, 5-(3',4'-dihydroxyphenyl)-valerolactone represents an important in vivo metabolite of (-)-epicatechin and procyanidin B1 produced by the gut microbiota.

Phenolic compounds, antioxidant activity and insulinotropic effect of extracts prepared from grape (Vitis vinifera L) byproducts

Grape byproducts are a rich source of phenolics having immense medicinal properties, but usually wasted from juice/wine processing industries. The present study investigates the phenolic antioxidants and the insulinotropic effect of extracts prepared from seed, skin and stems of two red wine grape cultivars: Pusa Navarang and Merlot. Pusa Navarang cultivar has shown high amounts of total phenolics (95.8 mg/ml), flavonoids (30.5 mg/ml) and flavan-3-ols (21.8 mg/ml) in seed extract and total anthocyanin (4.9 mg/ml) in its skin extract as compared to Merlot cultivar. As determined using HPLC, higher amounts of catechin hydrate (14909 mg/l) and epicatechin (9299 mg/l) were observed in its seed extract, while quercetin hydrate (5849 mg/l) was abundant in its skin extract. Similarly, ferric reducing antioxidant power (FRAP) and ABTS(+). [2,2'-azinobis (3-ethylbenzothiazoline)-6-sulfonic acid] and DPPH. (1,1-diphenyl-2-picrylhy- drazyl) radicals scavenging, were higher in its seed extract, respectively being 134.8 mg/ml of Quercetin equivalent (QE), 18.7 mM of trolox equivalent (TE) and 33.5 mM of TE. Strong correlation was obtained between FRAP and total phenolics, flavonoids and flavan-3-ols contents with correlation coefficients (r(2)) of 0.915, 0.738 and 0.838 respectively. Interestingly, there was a 2-8 fold increase in insulin secretion by isolated mice pancreatic islets at 5.5 mM and 16.5 mM glucose concentration in presence of various extracts. Overall, the seed, skin and stem byproducts of both cultivars are rich sources of phenolics and antioxidants and represent a source of new insulin secretagogues.

Characterization of microbial metabolism of Syrah grape products in an in vitro colon model using targeted and non-targeted analytical approaches

PURPOSE

Syrah red grapes are used in the production of tannin-rich red wines. Tannins are high molecular weight molecules, proanthocyanidins (PAs), and poorly absorbed in the upper intestine. In this study, gut microbial metabolism of Syrah grape phenolic compounds was investigated.

METHODS

Syrah grape pericarp was subjected to an enzymatic in vitro digestion model, and red wine and grape skin PA fraction were prepared. Microbial conversion was screened using an in vitro colon model with faecal microbiota, by measurement of short-chain fatty acids by gas chromatography (GC) and microbial phenolic metabolites using GC with mass detection (GC-MS). Red wine metabolites were further profiled using two-dimensional GC mass spectrometry (GCxGC-TOFMS). In addition, the effect of PA structure and dose on conversion efficiency was investigated by GC-MS.

RESULTS

Red wine exhibited a higher degree of C1-C3 phenolic acid formation than PA fraction or grape pericarp powders. Hydroxyphenyl valeric acid (flavanols and PAs as precursors) and 3,5-dimethoxy-4-hydroxybenzoic acid (anthocyanin as a precursor) were identified from the red wine metabolite profile. In the absence of native grape pericarp or red wine matrix, the isolated PAs were found to be effective in the dose-dependent inhibition of microbial conversions and short-chain fatty acid formation.

CONCLUSIONS

Metabolite profiling was complementary to targeted analysis. The identified metabolites had biological relevance, because the structures of the metabolites resembled fragments of their grape phenolic precursors or were in agreement with literature data.

Antiproliferative effect of catechin in GRX cells

The phenolic compounds present in cocoa seeds have been studied regarding health benefits, such as antioxidant and anti-inflammatory activities. Fibrosis is a wound healing response that occurs in almost all patients with chronic liver injury. A large number of cytokines and soluble intercellular mediators are related to changes in the behavior and phenotype of the hepatic stellate cell (HSC) that develop a fibrogenic and contractile phenotype leading to the development of fibrosis. The objective of this study was to assess the catechin effect in GRX liver cells in activities such as cell growth and inflammation. The GRX cells treatment with catechin induced a significant decrease in cell growth. This mechanism does not occur by apoptosis or even by autophagy because there were no alterations in expression of caspase 3 and PARP (apoptosis), and LC3 (autophagy). The expression of p27 and p53 proteins, regulators of the cell cycle, showed increased expression, while COX-2 and IL-6 mRNA showed a significant decrease in expression. This study shows that catechin decreases cell growth in GRX cells and, probably, this decrease does not occur by apoptosis or autophagy but through an anti-inflammatory effect and cell cycle arrest. Catechin also significantly decreased the production of TGF-β by GRX cells, showing a significant antifibrotic effect.

Procyanidins and inflammation: molecular targets and health implications

The inflammatory response has been implicated in the pathogenesis of many chronic diseases. Thus, the modulation of the inflammatory response by the consumption of bioactive food compounds, such as procyanidins, is a powerful tool to promote health. Procyanidin-mediated anti-inflammatory molecular mechanisms include, among others, the modulation of the arachidonic acid pathway, the inhibition of the gene transcription, protein expression and enzymatic activity of eicosanoid generating enzymes, the production and secretion of inflammatory mediators (such as cytokines and nitric oxide), the inhibition of mitogen-activated protein kinase (MAPK) pathway activation, and the modulation of the nuclear factor-κB (NF-κB) pathway. The NF-κB pathway can be regulated by procyanidins at several levels. During early events in NF-κB signaling, procyanidins modulate Iκκ activity, and the cytoplasmic retention of p65:p50 NF-κB by the inhibition of IκB phosphorylation and proteasomal degradation, while at late stages, they affect the nuclear translocation of pro/anti-inflammatory NF-κB homo/hetero dimers and their subsequent binding to the promoter regions of target genes. To identify and understand the value of procyanidins in the modulation of the inflammatory response, the molecular mechanisms underlying the anti-inflammatory activities and prohomeostatic effects of procyanidins need to be investigated further.

Intake estimation of total and individual flavan-3-ols, proanthocyanidins and theaflavins, their food sources and determinants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Epidemiological studies suggest health-protective effects of flavan-3-ols and their derived compounds on chronic diseases. The present study aimed to estimate dietary flavan-3-ol, proanthocyanidin (PA) and theaflavin intakes, their food sources and potential determinants in the European Prospective Investigation into Cancer and Nutrition (EPIC) calibration cohort. Dietary data were collected using a standardised 24 h dietary recall software administered to 36 037 subjects aged 35-74 years. Dietary data were linked with a flavanoid food composition database compiled from the latest US Department of Agriculture and Phenol-Explorer databases and expanded to include recipes, estimations and retention factors. Total flavan-3-ol intake was the highest in UK Health-conscious men (453·6 mg/d) and women of UK General population (377·6 mg/d), while the intake was the lowest in Greece (men: 160·5 mg/d; women: 124·8 mg/d). Monomer intake was the highest in UK General population (men: 213·5 mg/d; women: 178·6 mg/d) and the lowest in Greece (men: 26·6 mg/d in men; women: 20·7 mg/d). Theaflavin intake was the highest in UK General population (men: 29·3 mg/d; women: 25·3 mg/d) and close to zero in Greece and Spain. PA intake was the highest in Asturias (men: 455·2 mg/d) and San Sebastian (women: 253 mg/d), while being the lowest in Greece (men: 134·6 mg/d; women: 101·0 mg/d). Except for the UK, non-citrus fruits (apples/pears) were the highest contributors to the total flavan-3-ol intake. Tea was the main contributor of total flavan-3-ols in the UK. Flavan-3-ol, PA and theaflavin intakes were significantly different among all assessed groups. This study showed heterogeneity in flavan-3-ol, PA and theaflavin intake throughout the EPIC countries.

Assessment of Antioxidant Properties in Fruits of Myrica esculenta: A Popular Wild Edible Species in Indian Himalayan Region

Crude extract of Myrica esculenta fruits, a wild edible species of Indian Himalayan Region, was evaluated for phenolic compounds and antioxidant properties. Results revealed significant variation in total phenolic and flavonoid contents across populations. Among populations, total phenolic content varied between 1.78 and 2.51 mg gallic acid equivalent/g fresh weight (fw) of fruits and total flavonoids ranged between 1.31 and 1.59 mg quercetin equivalent/g fw. Antioxidant activity determined by 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging, 1,1-diphenyl-2-picrylhydrazyl radical scavenging and ferric reducing antioxidant power (FRAP) exhibited considerable antioxidant potential and showed significant positive correlation with total phenolic and total flavonoids content. High performance liquid chromatography analysis revealed significant variation (P <  .01) in phenolic compounds (i.e., gallic acid, catechin, hydroxybenzioc acid and ρ-coumaric acid) across populations. This study provides evidences to establish that consumption of M. esculenta fruits while providing relished taste would also help in reduction of free radicals. Therefore, this wild edible species deserves promotion in the region through horticulture and forestry interventions.

Chemoselective C-4 aerobic oxidation of catechin derivatives catalyzed by the Trametes villosa laccase/1-hydroxybenzotriazole system: synthetic and mechanistic aspects

Catechin derivatives were oxidized in air in the presence of the Trametes villosa laccase/1-hydroxybenzotriazole (HBT) system in buffered water/1,4-dioxane as reaction medium. The oxidation products, flavan-3,4-diols and the corresponding C-4 ketones, are bioactive compounds and useful intermediates for the hemisynthesis of proanthocyanidins, plant polyphenols which provide beneficial health properties for humans. Determinations of oxidation potentials excluded that catechin derivatives could be directly oxidized by laccase Cu(II), while it resulted in the H-abstraction from benzylic positions being promptly promoted by the enzyme in the presence of the mediator HBT, the parent species producing in situ the reactive intermediate benzotriazole-N-oxyl (BTNO) radical. A remarkable and unexpected result for the laccase/HBT oxidative system has been the chemoselective insertion of the oxygen atom into the C-4-H bond of catechin derivatives. Mechanistic aspects of the oxidation reaction have been investigated in detail for the first time in order to corroborate these results. Since the collected experimental findings could not alone provide information useful to clarify the origin of the observed chemoselectivity, these data were expressly supplemented with information derived by suitable molecular modeling investigations. The integrated evaluation of the dissociation energies of the C-H bonds calculated both by semiempirical and DFT methods and the differential activation energies of the process estimated by a molecular modeling approach suggested that the observed selective oxidation at the C-4 carbon has a kinetic origin.

Total phenolic compounds, flavonoids, and radical scavenging activity of 21 selected tropical plants

Free radical scavenging activity of 21 tropical plant extracts was evaluated using 1,1-diphenyl-2-picrylhydrazyl assay (DPPH). Total phenolic compounds and flavonoids were determined using Folin-Ciocalteu and HPLC, respectively. Results of the study revealed that all the plants tested exhibited excellent antioxidant activity with IC(50) in the range of 21.3 to 89.6 microg/mL. The most potent activity was demonstrated by Cosmos caudatus (21.3 microg/mL) and Piper betle (23.0 microg/mL) that are not significantly different than that of -tocopherol or BHA. L. inermis extract was found to consist of the highest concentration of phenolics, catechin, epicatechin, and naringenin. High content of quercetin, myricetin, and kaempferol were identified in Vitex negundo, Centella asiatica, and Sesbania grandiflora extracts, respectively. Luteolin and apigenin, on the other hand, were found in Premna cordifolia and Kaempferia galanga extracts. Strong correlation (R = 0.8613) between total phenolic compounds and total flavonoids (R = 0.8430) and that of antioxidant activity of the extracts were observed. The study revealed that phenolic, in particular flavonoids, may be the main contributors to the antioxidant activity exhibited by the plants.

PRACTICAL APPLICATION

Potent antioxidant from natural sources is of great interest to replace the use of synthetic antioxidants. In addition, some of the plants have great potential to be used in the development of functional ingredients/foods that are currently in demand for the health benefits associated with their use.

Effect of polyphenols on the intestinal and placental transport of some bioactive compounds

Polyphenols are a group of widely distributed phytochemicals present in most foods of vegetable origin. A growing number of biological effects have been attributed to these molecules in the past few years and only recently has their interference with the transport capacity of epithelial barriers received attention. This review will present data obtained concerning the effect of polyphenols upon the transport of some compounds (organic cations, glucose and the vitamins thiamin and folic acid) at the intestinal and placental barriers. Important conclusions can be drawn: (i) different classes of polyphenols affect transport of these bioactive compounds at the intestinal epithelia and the placenta; (ii) different compounds belonging to the same phenolic family often possess opposite effects upon transport of a given molecule; (iii) the acute and chronic/short-term and long-term exposures to polyphenols do not produce parallel results and, therefore, care should be taken when extrapolating results; (iv) the effect of polyphenolics in combination may be very different from the expected ones taking into account the effect of each of these compounds alone, and so care should be taken when speculating on the effect of a drink based on the effect of one component only; (v) care should be taken in drawing conclusions for alcoholic beverages from results obtained with ethanol alone. Although most of the data reviewed in the present paper refer to in vitro experiments with cell-culture systems, these studies raise a concern about possible changes in the bioavailability of substrates upon concomitant ingestion of polyphenols.

Flavonoid intake and disability-adjusted life years due to Alzheimer’s and related dementias: a population-based study involving twenty-three developed countries

Objective

Dietary flavonoids and their metabolites may have neuroprotective effects against age-associated neurodegenerative disorders such as Alzheimer’s and related dementias (dementia). There is a lack of population studies, however, on correlations between flavonoid intake and dementia. The main objective of the present study was to analyse such a relationship at a large-scale population level.

Design

Based on global data (FAO, WHO), databases were generated for: (i) flavonoid content of foods; (ii) per capita national dietary intakes of flavonoids and other dietary factors; and (iii) disability-adjusted life years – a measure of burden and death – due to dementia. Five major flavonoid subclasses were examined. To minimize influences due to accuracy and reliability of the disease source data, twenty-three developed countries were selected after statistical evaluation.

Results

Flavonols and combined flavonoids (all five combined) intakes were the only two parameters with significant (P < 0·05) negative dementia correlations. Multiple linear regression models confirmed this relationship, and excluded confounding from some other dietary and non-dietary factors. Similar analyses with non-dementia, neurological/psychiatric diseases did not yield significant correlations.

Conclusions

At a global level, and in the context of different genetic backgrounds, our results suggest that higher consumption of dietary flavonoids, especially flavonols, is associated with lower population rates of dementia in these countries.

Metabolites are key to understanding health effects of wine polyphenolics

Phenolic compounds in grapes and wine are grouped within the following major classes: stilbenes, phenolic acids, ellagitannins, flavan-3-ols, anthocyanins, flavonols, and proanthocyanidins. Consumption of foods containing phenolic substances has been linked to beneficial effects toward chronic diseases such as coronary heart disease and colorectal cancer. However, such correlations need to be supported by in vivo testing and bioavailability studies are the first step in establishing cause and effect. Class members from all phenolic groups can be glucuronidated, sulfated, and/or methylated and detected at low concentrations in the bloodstream and in urine. But the majority of phenolic compounds from grapes and wine are metabolized in the gastrointestinal tract, where they are broken down by gut microflora. This typically involves deglycosylation, followed by breakdown of ring structures to produce phenolic acids and aldehydes. These metabolites can be detected in bloodstream, urine, and fecal samples by using sophisticated instrumentation methods for quantitation and identification at low concentrations. The health effects related to grape and wine consumption may well be due to these poorly understood phenolic acid metabolites. This review discusses the known metabolism of each major class of wine and grape phenolics, the means to measure them, and ideas for future investigations.

Chemopreventive effect of raw and cooked lentils (Lens culinaris L) and soybeans (Glycine max) against azoxymethane-induced aberrant crypt foci

Although lentils (Lens culinaris L) contain several bioactive compounds that have been linked to the prevention of cancer, the in vivo chemopreventive ability of lentils against chemically induced colorectal cancer has not been examined. Our present study examined the hypothesis that lentils could suppress the early carcinogenesis in vivo by virtue of their bioactive micro- and macroconstituents and that culinary thermal treatment could affect their chemopreventive potential. To accomplish this goal, we used raw whole lentils (RWL), raw split lentils (RSL), cooked whole lentils (CWL), and cooked split lentils (CSL). Raw soybeans (RSB; Glycine max) were used for the purpose of comparison with a well-studied chemopreventive agent. Sixty weanling Fischer 344 male rats, 4 to 5 weeks of age, were randomly assigned to 6 groups (10 rats/group): the control group (C) received AIN-93G diet, and treatment leguminous groups of RWL, CWL, RSL, CSL, and RSB received the treatment diets containing AIN-93G+5% of the above-mentioned legumes. After acclimatization for 1 week (at 5th to 6th week of age), all animals were put on the control and treatment diets separately for 5 weeks (from 6th to 11th week of age). At the end of the 5th week of feeding (end of 11th week of age), all rats received 2 subcutaneous injections of azoxymethane carcinogen at 15 mg/kg rat body weight per dose once a week for 2 consecutive weeks. After 17 weeks of the last azoxymethane injection (from 12th to 29th week of age), all rats were euthanized. Chemopreventive ability was assessed using colonic aberrant crypt foci and activity of hepatic glutathione-S-transferases. Significant reductions (P < .05) were found in total aberrant crypt foci number (mean +/- SEM) for RSB (27.33 +/- 4.32), CWL (33.44 +/- 4.56), and RSL (37.00 +/- 6.02) in comparison with the C group (58.33 +/- 8.46). Hepatic glutathione-S-transferases activities increased significantly (P < .05) in rats fed all treatment diets (from 51.38 +/- 3.66 to 67.94 +/- 2.01 micromol mg(-1) min(-1)) when compared with control (C) diet (26.13 +/- 1.01 micromol mg(-1) min(-1)). Our findings indicate that consumption of lentils might be protective against colon carcinogenesis and that hydrothermal treatment resulted in an improvement in the chemopreventive potential for the whole lentils.

An analysis on flavonoids contents in Mao Luang fruits of fifteen cultivars (Antidesma bunius), grown in northeast Thailand

This investigation was carried out at the Department of Biotechnology, Faculty of Technology, Mahasarakham University, Mahasarakham Province, Northeast Thailand. The study aimed to analyze flavonoids contents in ripe fruits of fifteen Mao Luang cultivars (Antidesma bunius) harvested from dipterocarp forest of the mountainous areas of Phupan Valley, Sakon Nakhon Province, Northeast Thailand. The experiment was laid in a Completely Randomised Design (CRD) with five replications. The fifteen cultivars were used as treatments. An amount of 2 kg of ripe fruits of each cultivar was collected and extracted for juice solutions. The analysis was carried out with the use of RP-HPLC laboratory system. The results showed that fruits of the fifteen Mao Luang cultivars contained three different kinds of flavonoids, i.e., catechin, procyanidin B1 and procyanidin B2. These three chemical compounds were the major flavonoids in all analyzed fruit samples of the fifteen cultivars. The highest amount of procyanidin B1 was found with Lompat followed by Maeloogdog with values of 4122.75 and 3993.88 mg 100 g(-1) of fresh weight, respectively and the highest amount of procyanidin B2 was found with Sangkrow 2 followed by Fapratan with values of 5,006.39 and 3,689.42 mg 100 g(-1) of fresh weight, respectively. Catechin contents in fruits of the fifteen cultivars varied from 73.39 to 316.22 mg 100 g(-1) of fresh weight for Sangkrow 5 and Fapratan, respectively where Fapratan was the highest among the fifteen cultivars followed by Sangkrow 2 with values of 316.22 and 175.40 mg 100 g(-1) of fresh weight, respectively. In terms of grand total amounts of flavonoids, Sangkrow 2 was the best followed by Fapratan, Sangkrow 1 and Maeloogdog, whilst the rest were of secondary importance.

Factors affecting the conversion of apple polyphenols to phenolic acids and fruit matrix to short-chain fatty acids by human faecal microbiota in vitro

Proanthocyanidins (PAs) in apples are condensed tannins comprised mostly of (-)-epicatechin units with some terminal (+)-catechins. PAs, especially those having a long chain-length, are absorbed in the upper intestine only to a small extent and are passed to the colon. In the colon they are subjected to microbial metabolism by colonic microbiota. In the present article, the ability of human microbiota to ferment apple PAs is studied. Freeze-dried fruit preparations (apple, enzymatically digested apple, isolated cell-walls, isolated PAs or ciders) from two varieties, Marie Ménard and Avrolles, containing PAs of different chain lengths, were compared. Fermentation studies were performed in an in vitro colon model using human faecal microbiota as an inoculum. The maximal extent of conversion to known microbial metabolites, was observed at late time point for Marie Ménard cider, having short PAs. In this case, the initial dose also contributed to the extent of conversion. Long-chain PAs were able to inhibit the in vitro microbial metabolism of PAs shown as low maxima at early time points. Presence of isolated PAs also suppressed SCFA formation from carbohydrates as compared with that from apple cell wall or faecal suspension without substrates. The low maximal extents at early time points suggest that there is a competition between the inhibitory effect of the PAs on microbial activity, and the ability to convert PAs by the microbiota.

Procyanidin effects on adipocyte-related pathologies

Procyanidins, a class of flavonoids, have clear and well-defined beneficial effects against several pathologies including cardiovascular heart disease. Now, studies in vivo are revealing the effects of procyanidins against obesity, where they prevent weight gain and adipose tissue mass increase, and against diabetes and insulin resistance, where they act as antihiperglycemic agents. Several mechanisms may be responsible for these effects. One of these, due to the key role of adipose tissue in the development of obesity and insulin resistance, is their effect on adipocytes. In this review we compile the studies that indicate a protective role for procyanidins in obesity and insulin resistance, focusing on their effects on the adipocyte, where procyanidins modify lipid synthesis, lipid degradation, glucose uptake, and adipose differentiation.

New approach for the synthesis and isolation of dimeric procyanidins

A semisynthetic approach for the strategic formation of various procyanidins has been developed. Procyanidin-rich grape seed extracts were reacted with flavan-3-ols under acid catalysis. The reaction enables the formation of dimeric procyanidins and the elimination of higher oligomeric and polymeric procyanidins through degradation. An easy and fast method for the isolation of large amounts of procyanidins after semisynthetic formation by high-speed countercurrent chromatography is presented. Dimeric procyanidins (B1, B2, B3, B4, B5, and B7) were obtained and isolated. Furthermore, galloylated dimeric procyanidins [(-)-epicatechin-3- O-gallate-4beta-->8-(+)-catechin, (-)-epicatechin-3- O-gallate-4beta-->8-(-)-epicatechin, (-)-epicatechin-3- O-gallate-4beta-->6-(-)-epicatechin, and (-)-epicatechin-4beta-->8-(-)-epicatechin-3- O-gallate], as well as trimeric procyanidins [C1, (-)-epicatechin-4beta-->6-(-)-epicatechin-4beta-->8-(-)-epicatechin, and (-)-epicatechin-4beta-->6-(-)-epicatechin-4beta-->6-(+)-catechin] were obtained and isolated as side products. This approach also afforded gambiriins A1 and A2, which were all isolated and unambiguously identified, and the novel 3-(2,4,6-trihydroxyphenyl)-1-(3,4-dihydroxyphenyl)-propan-2-ol-1beta-->8-(-)-epicatechin (gambiriin A4).

Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials

BACKGROUND

The beneficial effects of flavonoid consumption on cardiovascular risk are supported by mechanistic and epidemiologic evidence.

OBJECTIVE

We aimed to systematically review the effectiveness of different flavonoid subclasses and flavonoid-rich food sources on cardiovascular disease (CVD) and risk factors--ie, lipoproteins, blood pressure, and flow-mediated dilatation (FMD).

DESIGN

Methods included a structured search strategy on MEDLINE, EMBASE, and Cochrane databases; formal inclusion or exclusion, data extraction, and validity assessment; and meta-analysis.

RESULTS

One hundred thirty-three trials were included. No randomized controlled trial studied effects on CVD morbidity or mortality. Significant heterogeneity confirmed differential effects between flavonoid subclasses and foods. Chocolate increased FMD after acute (3.99%; 95% CI: 2.86, 5.12; 6 studies) and chronic (1.45%; 0.62, 2.28; 2 studies) intake and reduced systolic (-5.88 mm Hg; -9.55, -2.21; 5 studies) and diastolic (-3.30 mm Hg; -5.77, -0.83; 4 studies) blood pressure. Soy protein isolate (but not other soy products or components) significantly reduced diastolic blood pressure (-1.99 mm Hg; -2.86, -1.12; 9 studies) and LDL cholesterol (-0.19 mmol/L; -0.24, -0.14; 39 studies). Acute black tea consumption increased systolic (5.69 mm Hg; 1.52, 9.86; 4 studies) and diastolic (2.56 mm Hg; 1.03, 4.10; 4 studies) blood pressure. Green tea reduced LDL (-0.23 mmol/L; -0.34, -0.12; 4 studies). For many of the other flavonoids, there was insufficient evidence to draw conclusions about efficacy.

CONCLUSIONS

To date, the effects of flavonoids from soy and cocoa have been the main focus of attention. Future studies should focus on other commonly consumed subclasses (eg, anthocyanins and flavanones), examine dose-response effects, and be of long enough duration to allow assessment of clinically relevant endpoints.

Saskatoon and wild blueberries have higher anthocyanin contents than other Manitoba berries

Studies have shown that anthocyanins present in berry fruits have some beneficial health effects such as reducing age-associated oxidative stress and possessing anti-inflammatory properties. Therefore, six Manitoba berries (wild blueberry, Saskatoon berry, raspberry, chokecherry, strawberry, and seabuckthorn) were studied for their anthocyanin compositions (mg/100 g) on dry weight basis. Saskatoon berry and wild blueberry showed a high content of total anthocyanins (562.4 and 558.3 mg/100 g, respectively) that were not significantly (P>0.05) different from each other. The corresponding values for other berries: raspberry (365.2 mg/100 g), chokecherry (177.39 mg/100 g), and strawberry (97.5 mg/100 g) were significantly different from each other (P<0.05), and the total anthocyanin content of seabuckthorn was negligible (0.84 mg/100 g). Fifteen major anthocyanins were isolated from Manitoba berries. Saskatoon berry and wild blueberry contained higher amounts of delphinidin 3-glucoside (Dp-3-glc), malvidin 3-glucoside (Mv-3-glc), and malvidin 3-galactoside (Mv-3-gal). Dp-3-glc was 263.8 (mg/100 g) in Saskatoon berry and 84.4 (mg/100 g) in wild blueberry, whereas the corresponding values for Mv-3-glc in these berries were 47.4 and 139.6 (mg/100 g), respectively. Raspberry, strawberry, and chokecherry contained higher amounts of cyanidin 3-glucoside (Cy-3-glc), cyanidin 3-rutinoside (Cy-3-rut), and pelargonidin 3-glucoside (Pg-3-glc). The total anthocyanin content of Manitoba fruits followed the order: Saskatoon berry and blueberry (high anthocyanin berries), raspberry and chokecherry (medium anthocyanin berries), strawberry (low anthocyanin berries), and seabuckthorn (negligible anthocyanin berries). This study demonstrated that Saskatoon berries and wild blueberries have high potential value for fruit growers as well as the food and nutraceutical manufacturers because of their high anthocyanin contents.