(Poly)phenols: The Missing Piece in the Puzzle of Inflammation.

Despite researchers' and clinicians' exponential understanding of chronic diseases' complexity, ranging from cancer, diabetes, and neurodegenerative disorders, we still have a lot of unanswered questions on pathobiology mechanisms, wherein inflammation is central [...].

Dietary (Poly)phenols in Traumatic Brain Injury.

Traumatic brain injury (TBI) remains one of the leading causes of death and disability in young adults worldwide. Despite growing evidence and advances in our knowledge regarding the multifaceted pathophysiology of TBI, the underlying mechanisms, though, are still to be fully elucidated. Whereas initial brain insult involves acute and irreversible primary damage to the brain, the processes of subsequent secondary brain injury progress gradually over months to years, providing a window of opportunity for therapeutic interventions. To date, extensive research has been focused on the identification of druggable targets involved in these processes. Despite several decades of successful pre-clinical studies and very promising results, when transferred to clinics, these drugs showed, at best, modest beneficial effects, but more often, an absence of effects or even very harsh side effects in TBI patients. This reality has highlighted the need for novel approaches that will be able to respond to the complexity of the TBI and tackle TBI pathological processes on multiple levels. Recent evidence strongly indicates that nutritional interventions may provide a unique opportunity to enhance the repair processes after TBI. Dietary (poly)phenols, a big class of compounds abundantly found in fruits and vegetables, have emerged in the past few years as promising agents to be used in TBI settings due to their proven pleiotropic effects. Here, we give an overview of the pathophysiology of TBI and the underlying molecular mechanisms, followed by a state-of-the-art summary of the studies that have evaluated the efficacy of (poly)phenols administration to decrease TBI-associated damage in various animal TBI models and in a limited number of clinical trials. The current limitations on our knowledge concerning (poly)phenol effects in TBI in the pre-clinical studies are also discussed.

Low Molecular Weight (poly)Phenol Metabolites Across the Blood-Brain Barrier: The Underexplored Journey.

The world of (poly)phenols arising from dietary sources has been significantly amplified with the discovery of low molecular weight (LMW) (poly)phenol metabolites resulting from phase I and phase II metabolism and microbiota transformations. These metabolites, which are known to reach human circulation have been studied to further explore their interesting properties, especially regarding neuroprotection. Nevertheless, once in circulation, their distribution to target tissues, such as the brain, relies on their ability to cross the blood-brain barrier (BBB), one of the most controlled barriers present in humans. This represents a key step of an underexplored journey towards the brain. Present review highlights the main findings related to the ability of LMW (poly)phenol metabolites to reach the brain, considering different studies: in silico, in vitro, and in vivo. The mechanisms associated with the transport of these LMW (poly)phenol metabolites across the BBB and possible transporters will be discussed. Overall, the transport of these LMW (poly)phenol metabolites is crucial to elucidate which compounds may exert direct neuroprotective effects, so it is imperative to continue dissecting their potential to cross the BBB and the mechanisms behind their permeation.

Berry-Enriched Diet in Salt-Sensitive Hypertensive Rats: Metabolic Fate of (Poly)Phenols and the Role of Gut Microbiota.

Diets rich in (poly)phenols are associated with a reduced reduction in the incidence of cardiovascular disorders. While the absorption and metabolism of (poly)phenols has been described, it is not clear how their metabolic fate is affected under pathological conditions. This study evaluated the metabolic fate of berry (poly)phenols in an in vivo model of hypertension as well as the associated microbiota response. Dahl salt-sensitive rats were fed either a low-salt diet (0.26% NaCl) or a high-salt diet (8% NaCl), with or without a berry mixture (blueberries, blackberries, raspberries, Portuguese crowberry and strawberry tree fruit) for 9 weeks. The salt-enriched diet promoted an increase in the urinary excretion of berry (poly)phenol metabolites, while the abundance of these metabolites decreased in faeces, as revealed by UPLC-MS/MS. Moreover, salt and berries modulated gut microbiota composition as demonstrated by 16S rRNA analysis. Some changes in the microbiota composition were associated with the high-salt diet and revealed an expansion of the families Proteobacteria and Erysipelotrichaceae. However, this effect was mitigated by the dietary supplementation with berries. Alterations in the metabolic fate of (poly)phenols occur in parallel with the modulation of gut microbiota in hypertensive rats. Thus, beneficial effects of (poly)phenols could be related with these interlinked modifications, between metabolites and microbiota environments.

Identification of insect-specific flaviviruses in areas of Brazil and Paraguay experiencing endemic arbovirus transmission and the description of a novel flavivirus infecting Sabethes belisarioi.

Viral infection was examined with pan-flavivirus and pan-alphavirus sets of primers in mosquitoes collected in four South American regions with confirmed pathogenic arbovirus circulation. Positive pools for flavivirus infection were sequenced and screened for specific arboviruses, which were not detected. However, NS5 gene sequencing showed that most sequences corresponded to the insect-specific Culex flavivirus. One sequence retrieved from an Aedes albopictus pool grouped with the insect-specific Aedes flavivirus and two Sabethes belisarioi pools were infected by a previously unknown flavivirus, tentatively named Sabethes flavivirus (SbFV). Phylogenetic inference placed SbFV as ancestral to a clade formed by Culiseta flavivirus, Mercadeo, and Calbertado. SbFV polyprotein showed an average aminoacidic identity of 51% in comparison to these flaviviruses. In vitro studies suggest that SbFV infects insect cells, but not vertebrate cells, therefore, we propose it as a new insect-specific flavivirus. These results highlight the wide distribution of insect-specific flaviviruses concomitant with the circulation of emergent arboviruses.

Genetic and biological characterisation of Zika virus isolates from different Brazilian regions

BACKGROUND Zika virus (ZIKV) infections reported in recent epidemics have been linked to clinical complications that had never been associated with ZIKV before. Adaptive mutations could have contributed to the successful emergence of ZIKV as a global health threat to a nonimmune population. However, the causal relationships between the ZIKV genetic determinants, the pathogenesis and the rapid spread in Latin America and in the Caribbean remain widely unknown. OBJECTIVES The aim of this study was to characterise three ZIKV isolates obtained from patient samples during the 2015/2016 Brazilian epidemics. METHODS The ZIKV genomes of these strains were completely sequenced and in vitro infection kinetics experiments were carried out in cell lines and human primary cells. FINDINGS Eight nonsynonymous substitutions throughout the viral genome of the three Brazilian isolates were identified. Infection kinetics experiments were carried out with mammalian cell lines A549, Huh7.5, Vero E6 and human monocyte-derived dendritic cells (mdDCs) and insect cells (Aag2, C6/36 and AP61) and suggest that some of these mutations might be associated with distinct viral fitness. The clinical isolates also presented differences in their infectivity rates when compared to the well-established ZIKV strains (MR766 and PE243), especially in their abilities to infect mammalian cells. MAIN CONCLUSIONS Genomic analysis of three recent ZIKV isolates revealed some nonsynonymous substitutions, which could have an impact on the viral fitness in mammalian and insect cells.

Polyphenols, their Metabolites and Derivatives as Drug Leads.

In this non-comprehensive review, the potential of natural polyphenols as lead compounds for the design and synthesis of new molecules with potential application in several diseases was highlighted. Organic synthesis has been essential for the development of new analogues of naturally found polyphenols, providing a wide range of structural modifications for structure-activity relationship studies and improving or modulating the biological activity of the promising compounds.

Polyphenols Beyond Barriers: A Glimpse into the Brain.

BACKGROUND: Ageing can be simply defined as the process of becoming older, which is genetically determined but also environmentally modulated. With the continuous increase of life expectancy, quality of life during ageing has become one of the biggest challenges of developed countries. The quest for a healthy ageing has led to the extensive study of plant polyphenols with the aim to prevent age-associated deterioration and diseases, including neurodegenerative diseases. The world of polyphenols has fascinated researchers over the past decades, and in vitro, cell-based, animal and human studies have attempted to unravel the mechanisms behind dietary polyphenols neuroprotection. METHODS: In this review, we compiled some of the extensive and ever-growing research in the field, highlighting some of the most recent trends in the area. RESULTS: The main findings regarding polypolyphenols neuroprotective potential performed using in vitro, cellular and animal studies, as well as human trials are covered in this review. Concepts like bioavailability, polyphenols biotransformation, transport of dietary polyphenols across barriers, including the blood-brain barrier, are here explored. CONCLUSION: The diversity and holistic properties of polypolyphenol present them as an attractive alternative for the treatment of multifactorial diseases, where a multitude of cellular pathways are disrupted. The underlying mechanisms of polypolyphenols for nutrition or therapeutic applications must be further consolidated, however there is strong evidence of their beneficial impact on brain function during ageing. Nevertheless, only the tip of the iceberg of nutritional and pharmacological potential of dietary polyphenols is hitherto understood and further research needs to be done to fill the gaps in pursuing a healthy ageing.

Cranberry (poly)phenol metabolites correlate with improvements in vascular function: A double-blind, randomized, controlled, dose-response, crossover study.

SCOPE: Cranberries are rich in potentially bioactive (poly)phenols. The aim of this paper was to investigate whether cranberry juice intake can improve vascular function in healthy men in a dose- and time-dependent manner, and to understand which of the circulating (poly)phenol metabolites correlate with vascular effects. METHODS AND RESULTS: A double-blind randomized controlled crossover trial was conducted in ten healthy males. Flow-mediated dilation (FMD), blood pressure, pulse wave velocity and augmentation index were investigated at baseline, 1, 2, 4, 6, and 8 h post-consumption of cranberry juices containing 409, 787, 1238, 1534, and 1910 mg of total cranberry (poly)phenols (TP), and a control drink. Plasma (poly)phenol metabolites were analyzed by UPLC-Q-TOF MS using authentic standards. We observed dose-dependent increases in FMD at 1, 2, 4, 6, and 8 h with a peak at 4 h and maximal effects with juice containing 1238 mg TP. A total of 60 metabolites were quantified in plasma after cranberry consumption. Twelve (poly)phenol metabolites significantly correlated with the increases in FMD, including ferulic and caffeic acid sulfates, quercetin-3-O-ß-D-glucuronide and a γ-valerolactone sulfate. CONCLUSION: (Poly)phenols in cranberry juice can improve vascular function in healthy males and this is linked to the presence of specific newly identified plasma metabolites.

Quinic acid derivatives inhibit dengue virus replication in vitro.

BACKGROUND: Dengue is the most prevalent arboviral disease in tropical and sub-tropical areas of the world. The incidence of infection is estimated to be 390 million cases and 25,000 deaths per year. Despite these numbers, neither a specific treatment nor a preventive vaccine is available to protect people living in areas of high risk. RESULTS: With the aim of seeking a treatment that can mitigate dengue infection, we demonstrated that the quinic acid derivatives known as compound 2 and compound 10 were effective against all four dengue virus serotypes and safe for use in a human hepatoma cell line (Huh7.5). Both compounds were non-virucidal to dengue virus particles and did not interfere with early steps of the dengue virus life cycle, including binding and internalization. Experiments using a replicon system demonstrated that compounds 2 and 10 impaired dengue virus replication in Huh7.5 cells. Additionally, the anti-dengue virus effects of the quinic acid derivatives were preserved in human peripheral blood mononuclear cells. CONCLUSIONS: Taken together, these data suggest that quinic acid derivatives represent a novel chemical class of active compounds that could be used to combat dengue virus infection.

Immature dendritic cells generated from cryopreserved human monocytes show impaired ability to respond to LPS and to induce allogeneic lymphocyte proliferation.

Dendritic cells play a key role in the immune system, in the sensing of foreign antigens and triggering of an adaptive immune response. Cryopreservation of human monocytes was investigated to understand its effect on differentiation into immature monocyte-derived dendritic cells (imdDCs), the response to inflammatory stimuli and the ability to induce allogeneic lymphocyte proliferation. Cryopreserved (crp)-monocytes were able to differentiate into imdDCs, albeit to a lesser extent than freshly (frh)-obtained monocytes. Furthermore, crp-imdDCs had lower rates of maturation and cytokine/chemokine secretion in response to LPS than frh-imdDCs. Lower expression of Toll-like receptor 4 (at 24 and 48 h) and higher susceptibility to apoptosis in crp-imdDCs than in fresh cells would account for the impaired maturation and cytokine/chemokine secretion observed. A mixed leukocyte reaction showed that lymphocyte proliferation was lower with crp-imdDCs than with frh-imdDCs. These findings suggested that the source of monocytes used to generate human imdDCs could influence the accuracy of results observed in studies of the immune response to pathogens, lymphocyte activation, vaccination and antigen sensing. It is not always possible to work with freshly isolated monocytes but the possible effects of freezing/thawing on the biology and responsiveness of imdDCs should be taken into account.

Dendritic cell apoptosis and the pathogenesis of dengue.

Dengue viruses and other members of the Flaviviridae family are emerging human pathogens. Dengue is transmitted to humans by Aedes aegypti female mosquitoes. Following infection through the bite, cells of the hematopoietic lineage, like dendritic cells, are the first targets of dengue virus infection. Dendritic cells (DCs) are key antigen presenting cells, sensing pathogens, processing and presenting the antigens to T lymphocytes, and triggering an adaptive immune response. Infection of DCs by dengue virus may induce apoptosis, impairing their ability to present antigens to T cells, and thereby contributing to dengue pathogenesis. This review focuses on general mechanisms by which dengue virus triggers apoptosis, and possible influence of DC-apoptosis on dengue disease severity.

Antioxidant capacity of Macaronesian traditional medicinal plants.

The use of many traditional medicinal plants is often hampered by the absence of a proper biochemical characterization, essential to identify the bioactive compounds present. The leaves from five species endemic to the Macaronesian islands with recognized ethnobotanical applications were analysed: Apollonias barbujana (Cav.) Bornm., Ocotea foetens (Ainton) Baill, Prunus azorica (Mouill.) Rivas-Mart., Lousã, Fern. Prieto, E. Días, J.C. Costa & C. Aguiar, Rumex maderensis Lowe and Plantago arborescens Poir. subsp. maderensis (Dcne.) A. Hans. et Kunk.. Since oxidative stress is a common feature of most diseases traditionally treated by these plants, it is important to assess their antioxidant capacity and determine the molecules responsible for this capacity. In this study, the antioxidant capacity of these plants against two of the most important reactive species in human body (hydroxyl and peroxyl radicals) was determined. To trace the antioxidant origin total phenol and flavonoid contents as well as the polyphenolic profile and the amount of trace elements were determined. There was a wide variation among the species analysed in what concerns their total leaf phenol and flavonoid contents. From the High Performance Liquid Chromatography (HPLC) electrochemically detected peaks it was possible to attribute to flavonoids the antioxidant capacity detected in A. barbujana, O. foetens, R. maderensis and P. azorica extracts. These potential reactive flavonoids were identified for A. barbujana, R. maderensis and P. azorica. For R. maderensis a high content (7 mg g-1 dry weight) of L-ascorbic acid, an already described antioxidant phytomolecule, was found. A high content in selenomethionine (414.35 microg g-1 dry weight) was obtained for P. arborescens subsp. maderensis extract. This selenocompound is already described as a hydroxyl radical scavenger is reported in this work as also possessing peroxyl radical scavenging capacity. This work is a good illustration of different phytomolecules (flavonoids, organic acids and selenocompounds), presents in leaves of the five traditional medicinal plants endemic to Macaronesia, all exhibiting antioxidant properties.

Hantavirus infection in Brazil: development and evaluation of an enzyme immunoassay and immunoblotting based on N recombinant protein.

The symptoms of hantavirus pulmonary syndrome may resemble those of other febrile illnesses. The development of an accurate diagnostic test should therefore improve clinical prognosis and be useful in epidemiologic studies. We evaluated the use of a recombinant antigen (rNDelta(85)) based on the S-segment sequences of a Brazilian hantavirus for detecting immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against hantavirus in an indirect enzyme immunoassay (EIA). We assayed 613 serum samples (570 from humans and 43 from rodents). IgM EIA had a sensitivity of 94.1% and a specificity of 99.1%. IgG EIA had a sensitivity of 95.2% and a specificity of 98.4%. This evaluation confirms that rNDelta(85) IgM and IgG EIA tests are potentially useful rapid, sensitive, and cost-effective tools for detecting antibodies against hantaviruses indigenous to Brazil and other South American countries, in patients with acute or convalescent hantavirus infection, and in rodent reservoirs.

Genome analysis of dengue type-1 virus isolated between 1990 and 2001 in Brazil reveals a remarkable conservation of the structural proteins but amino acid differences in the non-structural proteins.

We have investigated the genetic diversity of dengue type-1 (DEN-1) virus in Brazil. The full nucleotide sequences of three DEN-1 virus isolated from DEN fever (DF) and DEN hemorrhagic fever patients in northeastern Brazil in 1997 (BR/97) and one from a DF patient in the south of Brazil in 2001 (BR/01) were compared to that of the reference strain BR/90 obtained in the city of Rio de Janeiro in 1990. Sequence analysis showed that the structural proteins were remarkably conserved between all isolates. A total of 27 amino acid changes occurred throughout the non-structural proteins. Among them, nine amino acid substitutions were specific of BR/97 and BR/01 isolates, indicating that in situ evolution of these strains had occurred. Within the BR/97 and BR/01 samples, some amino acid substitutions have been previously identified in DEN-1 virus strains sequenced so far, suggesting that recombination events might have occurred.