Polyphenols' Impact on Selected Biomarkers of Brain Aging in Healthy Middle-Aged and Elderly Subjects: A Review of Clinical Trials.

With a constantly growing elderly population, incidences of neurodegenerative diseases are also rising and are expected to further increase over the next years, while costing health systems across the world trillions of dollars. Therefore, biomarkers to detect manifestations of brain aging early and interventions to slow down its pace are of great interest. In the last years, the importance of the neurotrophins brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the context of cognitive function and the aging brain has increased, besides the already well-established amyloid-beta (Aß) and tau plaques. Due to their wide range of beneficial health effects as well as their antioxidant and anti-inflammatory properties, a class of secondary plant-metabolites, the so-called polyphenols, gained increasing attention. In this review, we discuss the roles of BDNF, Aß, NGF, and tau proteins as biomarkers of brain aging and the effect of dietary polyphenol interventions on these biomarkers, assessed via blood analysis, magnetic resonance imaging (MRI), and positron emission tomography (PET).

Effects of long-term consumption of two plant-based dietary supplements on cardiovascular health and low-grade inflammation in middle-aged and elderly people: study protocol for a randomised, controlled trial.

BACKGROUND: Ageing is a process characterised by chronic low-grade inflammation and oxidative stress which could lead to increased prevalence of both physical and mental age-related chronic conditions. A healthy balanced diet, rich in fruit and vegetables as well as omega-3 polyunsaturated fatty acids (n3 PUFA), could reduce oxidative stress and improve markers of low-grade inflammation. Nonetheless, considering that a large part of the population struggles to meet current guidelines on fruit and vegetable and n3 PUFA recommendations, fruit and vegetable concentrate supplements and mixed omega fatty acid supplements could be an effective strategy to bridge the gap between actual and recommended intakes. METHODS: In this randomised, controlled, open-labelled, parallel-grouped clinical trial, 112 participants will be allocated to one of four arms (n = 28 on each arm): an encapsulated juice powder concentrate, a plant-based omega fatty acid supplement, both or a control group. We aim to investigate whether long-term separate or combined ingestion of the two can affect biomarkers of cardiovascular health, low-grade inflammation and indicators of ageing, including cognitive function, in middle-aged and elderly people. We will additionally explore the effect of the different supplementations on plasma levels of vitamins, carotenoids and fatty acids. Intervention will last 2 years and participants will be assessed at baseline and at follow-up visits at 6, 12, 18 and 24 months. DISCUSSION: This study will provide evidence whether long-term, plant-based dietary supplementation can support cardiovascular health, anti-inflammatory processes, immunity and nutritional status in ageing. Trial registration This trial was registered at ClinicalTrials.gov (NCT04763291) on February 21, 2021.

Orthostatic Challenge-Induced Coagulation Activation in Young and Older Persons.

The incidence of thrombosis increases with aging. We investigated the coagulatory/haemostatic system across the ages and tested the hypothesis that older persons have a hypercoagulable state compared to younger persons at rest, and that standing up (orthostasis) leads to greater changes in coagulation in older persons. In total, 22 older and 20 young participants performed a 6 min sit-to-stand test (orthostatic challenge). Blood was collected prior to and at the end of standing and haemostatic profiling was performed via thrombelastometry (TEM), calibrated automated thrombogram (CAT) and standard coagulation assays. At baseline, three CAT-derived values indicated enhanced capability to generate thrombin in older participants. However, other measured parameters did not suggest a hypercoagulable state in older participants: prolonged TEM-derived coagulation times (295 vs. 209 s, medians, p = 0.0025) and prothrombin times (103 vs. 114%, medians, p = 0.0087), as well as lower TF levels (440 vs. 672 pg/mL, medians, p = 0.0245) and higher t-PA levels (7.3 vs. 3.8 ng/mL, medians, p = 0.0002), indicative of enhanced fibrinolytic capability, were seen. Younger participants were more sensitive to the orthostatic challenge: CAT-derived endogenous thrombin potentials (ETPs) were only increased in the young (1337 to 1350 nM.min, medians, p = 0.0264) and shortening of PTs was significantly higher in the young vs. older participants (p = 0.0242). Our data suggest that the increased thrombosis propensity in older persons is not primarily attributable to a hyperactive coagulation cascade but may be due to other pathologies associated with aging.

Immunomodulatory Effects of Aronia Juice Polyphenols-Results of a Randomized Placebo-Controlled Human Intervention Study and Cell Culture Experiments.

Dietary polyphenols, which are present in Aronia melanocarpa, have been associated with various beneficial effects on human health including antioxidant, antiviral, and anti-inflammatory activities. We aimed to investigate the immunomodulatory effects of aronia juice polyphenols in a randomized placebo-controlled human intervention study and cell culture experiments. A total of 40 females were asked to consume either 200 mL of aronia juice or a placebo drink for six weeks and were investigated again after a washout period of another six weeks. We observed that only half of the participants tolerated the aronia juice well (Vt) and the other half reported complaints (Vc). The placebo (P) was generally tolerated with one exception (p = 0.003). Plasma polyphenol levels increased significantly in Vt after the intervention (p = 0.024) but did neither in P nor in Vc. Regulatory T cell (Treg) frequencies remained constant in Vt and P during the intervention, whereas Tregs decreased in Vc (p = 0.018). In cell culture, inhibiting effects of ferulic acid (p = 0.0005) and catechin (p = 0.0393) on the differentiation of Tregs were observed as well as reduced activation of CD4-T cells in ferulic acid (p = 0.0072) and aronia juice (p = 0.0163) treated cells. Interestingly, a CD4+CD25-FoxP3+ cell population emerged in vitro in response to aronia juice, but not when testing individual polyphenols. In conclusion, our data strengthen possible individual hormetic effects, the importance of the food matrix for bioactivity, and the need for further investigations on possible impacts of specific physiological features such as the gut microbiota in the context of personalized nutrition.

Whole-Genome Investigation of Salmonella Dublin Considering Mountain Pastures as Reservoirs in Southern Bavaria, Germany.

Worldwide, Salmonella Dublin (S. Dublin) is responsible for clinical disease in cattle and also in humans. In Southern Bavaria, Germany, the serovar was identified as a causative agent for 54 animal disease outbreaks in herds between 2017 and 2021. Most of these emerged from cattle herds (n = 50). Two occurred in pig farms and two in bovine herds other than cattle. Genomic analysis of 88 S. Dublin strains isolated during these animal disease outbreaks revealed 7 clusters with 3 different MLST-based sequence types and 16 subordinate cgMLST-based complex types. Antimicrobial susceptibility investigation revealed one resistant and three intermediate strains. Furthermore, only a few genes coding for bacterial virulence were found among the isolates. Genome analysis enables pathogen identification and antimicrobial susceptibility, serotyping, phylogeny, and follow-up traceback analysis. Mountain pastures turned out to be the most likely locations for transmission between cattle of different herd origins, as indicated by epidemiological data and genomic traceback analyses. In this context, S. Dublin shedding was also detected in asymptomatic herding dogs. Due to the high prevalence of S. Dublin in Upper Bavaria over the years, we suggest referring to this administrative region as "endemic". Consequently, cattle should be screened for salmonellosis before and after mountain pasturing.

Fracture toughness and crack resistance curves of acrylic bone cements.

The fracture toughness KIc of 11 clinically used acrylic bone cements was studied in air at room temperature with single edge V-notched beam specimens. By driving the crack step-wise through the specimens, crack resistance curves ("R-curves") were recorded. One group of bone cements showed an increase of the fracture toughness with increasing crack length (including CMW1+G and several Palacos bone cements) whereas another group (including Simplex, SmartSet, Copal and some Palacos bone cements) did not exhibit an R-curve behavior. The plateau values for KIc ranged from 0.93 MPa√m (Simplex P) to 1.98 MPa√m (Palacos R+G). The observation of the crack growth with an optical microscope revealed some mechanisms influencing the crack growth like the formation of microcracks in the extended damage zone of the crack tip, the attraction of the crack by inclusions or the shielding of the crack tip by bridges in the wake of the crack. Furthermore, bone cements could be distinguished by the pattern of the path the crack followed during propagation. The crack pattern of CMW1+G provides a possible explanation of the distinct R-curve behavior of this cement.

Rpv3-1 mediated resistance to grapevine downy mildew is associated with specific host transcriptional responses and the accumulation of stilbenes.

BACKGROUND: European grapevine cultivars (Vitis vinifera spp.) are highly susceptible to the downy mildew pathogen Plasmopara viticola. Breeding of resistant V. vinifera cultivars is a promising strategy to reduce the impact of disease management. Most cultivars that have been bred for resistance to downy mildew, rely on resistance mediated by the Rpv3 (Resistance to P. viticola) locus. However, despite the extensive use of this locus, little is known about the mechanism of Rpv3-mediated resistance. RESULTS: In this study, Rpv3-mediated defense responses were investigated in Rpv3+ and Rpv3- grapevine cultivars following inoculation with two distinct P. viticola isolates avrRpv3+ and avrRpv3-, with the latter being able to overcome Rpv3 resistance. Based on comparative microscopic, metabolomic and transcriptomic analyses, our results show that the Rpv3-1-mediated resistance is associated with a defense mechanism that triggers synthesis of fungi-toxic stilbenes and programmed cell death (PCD), resulting in reduced but not suppressed pathogen growth and development. Functional annotation of the encoded protein sequence of genes significantly upregulated during the Rpv3-1-mediated defense response revealed putative roles in pathogen recognition, signal transduction and defense responses. CONCLUSION: This study used histochemical, transcriptomic and metabolomic analyses of Rpv3+ and susceptible cultivars inoculated with avirulent and virulent P. viticola isolates to investigate mechanism underlying the Rpv3-1-mediated resistance response. We demonstrated a strong correlation between the expressions of stilbene biosynthesis related genes, the accumulation of fungi-toxic stilbenes, pathogen growth inhibition and PCD.

Impact of pulsed UV-B stress exposure on plant performance: How recovery periods stimulate secondary metabolism while reducing adaptive growth attenuation.

Upon continuous stress exposure, plants display attenuated metabolic stress responses due to regulatory feedback loops. Here, we have tested the hypothesis that pulsed stress exposure with intervening recovery periods should affect these feedback loops, thereby causing increased accumulation of stress-induced metabolites. The response of Arabidopsis plantlets to continuous UV-B exposure (Cuv ) was compared with that of pulsed UV-B exposure (Puv ). The differential responses to Puv versus Cuv were monitored at the level of gene expression and metabolite accumulation, using wild type (WT) and different mutant lines. In comparison with Cuv , Puv increased sinapyl and flavonol (S + F) content, whereas adaptive growth attenuation was reduced. Furthermore, in a myb4 mutant (AtMYB4, repressor-type R2R3-MYB transcription factor), the S + F content was increased only for Cuv , but not beyond the level for Puv observed in WT. These observations and the ability of AtMYB4 to repress AtMYB12/AtMYB111-mediated activation of target gene promoters (pCHS and pFLS) indicate that the increase of S + F content after Puv observed in WT plants results from reduced feedback inhibition by AtMYB4. The results support the notion that stress-induced metabolic changes not necessarily cause a growth penalty. Furthermore, the observed Puv -induced increase in flavonol accumulation may stimulate reevaluation of commercial plant production practices.

Combinatorial Regulation of Stilbene Synthase Genes by WRKY and MYB Transcription Factors in Grapevine (Vitis vinifera L.).

Stilbene synthase (STS) is the key enzyme leading to the biosynthesis of resveratrol. Recently we reported two R2R3-MYB transcription factor (TF) genes that regulate the stilbene biosynthetic pathway in grapevine: VviMYB14 and VviMYB15. These genes are strongly co-expressed with STS genes under a range of stress and developmental conditions, in agreement with the specific activation of STS promoters by these TFs. Genome-wide gene co-expression analysis using two separate transcriptome compendia based on microarray and RNA sequencing data revealed that WRKY TFs were the top TF family correlated with STS genes. On the basis of correlation frequency, four WRKY genes, namely VviWRKY03, VviWRKY24, VviWRKY43 and VviWRKY53, were further shortlisted and functionally validated. Expression analyses under both unstressed and stressed conditions, together with promoter-luciferase reporter assays, suggested different hierarchies for these TFs in the regulation of the stilbene biosynthetic pathway. In particular, VviWRKY24 seems to act as a singular effector in the activation of the VviSTS29 promoter, while VviWRKY03 acts through a combinatorial effect with VviMYB14, suggesting that these two regulators may interact at the protein level as previously reported in other species.

Comparative protein profile analysis of wines made from Botrytis cinerea infected and healthy grapes reveals a novel biomarker for gushing in sparkling wine.

Fungal infection of grapes with the plant pathogenic fungus Botrytis (B.) cinerea was shown to cause a degradation of proteins in the resulting wine. Moreover, it influences the foaming properties of the wine. The aim of this study was to compare the protein composition in B. cinerea infected and healthy grapes and of wines produced from such grapes as well as to analyze whether the resulting changes in the protein profiles can be related the occurrence of gushing in sparkling wine. SDS-PAGE and reversed phase HPLC were applied to analyze the protein composition of healthy and botrytized grapes and of wines made from botrytized and healthy grapes. B. cinerea infection led to a general decrease of protein content in infected grapes and wines suggesting proteolytic activity of this fungus. Especially the concentration of a protein with a protein band at ~17kDa underwent a significant decrease in wine made from infected grapes. This protein was identified as Seripauperin 5 (PAU5) from Saccharomyces cerevisiae. A degradation of PAU5 and other proteins and the occurrence of a laccase from B. cinerea were observed in a gushing sparkling wine. Screening of sparkling wines showed that samples lacking PAU5 had a high probability for the occurrence of gushing. We suggest that the absence of protein PAU5 might be a useful biomarker for the occurrence of gushing in sparkling wine.

The photomorphogenic factors UV-B RECEPTOR 1, ELONGATED HYPOCOTYL 5, and HY5 HOMOLOGUE are part of the UV-B signalling pathway in grapevine and mediate flavonol accumulation in response to the environment.

Grapevine (Vitis vinifera L.) is a species well known for its adaptation to radiation. However, photomorphogenic factors related to UV-B responses have not been molecularly characterized. We cloned and studied the role of UV-B RECEPTOR (UVR1), ELONGATED HYPOCOTYL 5 (HY5), and HY5 HOMOLOGUE (HYH) from V. vinifera We performed gene functional characterizations, generated co-expression networks, and tested them in different environmental conditions. These genes complemented the Arabidopsis uvr8 and hy5 mutants in morphological and secondary metabolic responses to radiation. We combined microarray and RNA sequencing (RNA-seq) data with promoter inspections to identify HY5 and HYH putative target genes and their DNA binding preferences. Despite sharing a large set of common co-expressed genes, we found different hierarchies for HY5 and HYH depending on the organ and stress condition, reflecting both co-operative and partially redundant roles. New candidate UV-B gene markers were supported by the presence of HY5-binding sites. These included a set of flavonol-related genes that were up-regulated in a HY5 transient expression assay. We irradiated in vitro plantlets and fruits from old potted vines with high and low UV-B exposures and followed the accumulation of flavonols and changes in gene expression in comparison with non-irradiated conditions. UVR1, HY5, and HYH expression varied with organ, developmental stage, and type of radiation. Surprisingly, UVR1 expression was modulated by shading and temperature in berries, but not by UV-B radiation. We propose that the UV-B response machinery favours berry flavonol accumulation through the activation of HY5 and HYH at different developmental stages at both high and low UV-B exposures.