Impact of Flavonoids on Cellular and Molecular Mechanisms Underlying Age-Related Cognitive Decline and Neurodegeneration

Purpose of Review This review summarises the most recent evidence regarding the effects of dietary flavonoids on age-related cognitive decline and neurodegenerative diseases. Recent Findings Recent evidence indicates that plant-derived flavonoids may exert powerful actions on mammalian cognition and protect against the development of age-related cognitive decline and pathological neurodegeneration. The neuroprotective effects of flavonoids have been suggested to be due to interactions with the cellular and molecular architecture of brain regions responsible for memory. Summary Mechanisms for the beneficial effects of flavonoids on age-related cognitive decline and dementia are discussed, including modulating signalling pathways critical in controlling synaptic plasticity, reducing neuroinflammation, promoting vascular effects capable of stimulating new nerve cell growth in the hippocampus, bidirectional interactions with gut microbiota and attenuating the extracellular accumulation of pathological proteins. These processes are known to be important in maintaining optimal neuronal function and preventing age-related cognitive decline and neurodegeneration

Dietary patterns, caloric restrictions for management of cardiovascular disease and cancer; a brief review

Cardiovascular disease (CVD) and cancers are overall still identified as the two most prevalent non-communicable diseases globally. Their prevention and potential reversal (in particular CVD risk) was seen effective with the modification of dietary intake that was applied in several different populations. Although the findings from epidemiological studies provide support that adhering to dietary patterns such as the Mediterranean diet can reduce incidence and prevalence of CVD and some forms of cancer, the mechanistic aspects of disease modulation associated with both diseases can be seen in dietary management. Several studies have already explored the potential modes of action of certain nutrients in well controlled large clinical trials. However, the clinical trials designed to determine the effects of adhering to a particular diet are relatively hard to conduct and these studies are faced with several obstacles particularly in the populations that are identified with a high risk of CVD or different cancers. Therefore, it is important to understand potential underlying and shared mechanisms of action and to explore how healthy dietary patterns may modulate the occurrence, initiation, and progression of such diseases. The aim of this review is to summarise and conceptualize the current understanding relating to healthy dietary patterns, and briefly discuss the opportunities that epigenetic research may bring and how it may assist to further interpret epidemiological and clinical evidence

Anthocyanins and their gut metabolites reduce the adhesion of monocyte to TNFα-activated endothelial cells at physiologically relevant concentrations

An increasing number of evidence suggests a protective role of dietary anthocyanins against cardiovascular diseases. Anthocyanins' extensive metabolism indicates that their metabolites could be responsible for the protective effects associated with consumption of anthocyanin-rich foods. The aim of this work was to investigate the effect of plasma anthocyanins and their metabolites on the adhesion of monocytes to TNFα-activated endothelial cells and on the expression of genes encoding cell adhesion molecules. Human umbilical vein endothelial cells (HUVECs) were exposed to circulating anthocyanins: cyanidin-3-arabinoside, cyanidin-3-galactoside, cyanidin-3-glucoside, delphinidin-3-glucoside, peonidin-3-glucoside, anthocyanin degradation product: 4-hydroxybenzaldehyde, or to their gut metabolites: protocatechuic, vanillic, ferulic and hippuric acid, at physiologically-relevant concentrations (0.1–2 μM) and time of exposure. Both anthocyanins and gut metabolites decreased the adhesion of monocytes to HUVECs, with a magnitude ranging from 18.1% to 47%. The mixture of anthocyanins and that of gut metabolites also reduced monocyte adhesion. However, no significant effect on the expression of genes encoding E-selectin, ICAM1 and VCAM1 was observed, suggesting that other molecular targets are involved in the observed effect. In conclusion, this study showed the potency of anthocyanins and their gut metabolites to modulate the adhesion of monocytes to endothelial cells, the initial step in atherosclerosis development, under physiologically-relevant conditions

Antihyperlipidemic potential of dietary supplementation with carnosine in high-fat diet-fed rats

OBJECTIVE: The aim of this study was to investigate the hypolipidemic effects of carnosine and a commercial carnosine supplement on lipid status, liver and kidney function, and inflammation associated with dyslipidemia in rats with high-fat diet-induced hyperlipidemia. MATERIALS AND METHODS: The study was conducted on adult male Wistar rats, divided into control and experimental groups. Animals were kept in standard laboratory conditions and according to groups were treated with saline, carnosine, carnosine dietary supplement, simvastatin, and their combinations. All substances were prepared fresh every day and used by oral gavage. RESULTS: Treatment with a carnosine-based supplement significantly improved total and LDL cholesterol levels in serum, especially in the combination with simvastatin as a conventional drug in dyslipidemia treatment. The effect of carnosine on the metabolism of triglycerides was not as evident as in the case of cholesterol. Nevertheless, the values of the atherogenic index showed that the combinations of carnosine and carnosine supplement with simvastatin were the most effective in lowering this comprehensive lipid index. Dietary carnosine supplementation resulted also in anti-inflammatory effects, as demonstrated by immunohistochemical analyses. Besides, the good safety profile of carnosine in terms of its effect on liver and kidney functions was also confirmed. CONCLUSIONS: The use of carnosine supplements in preventing and/or treatment of metabolic disorders requires further investigations into the mechanisms of action and potential interactions with conventional therapy

Systematic bioinformatic analysis of nutrigenomic data of flavanols in cell models of cardiometabolic disease

Flavanol intake positively influences several cardiometabolic risk factors in humans. However, the specific molecular mechanisms of action of flavanols, in terms of gene regulation, in the cell types relevant to cardiometabolic disease have never been systematically addressed. On this basis, we conducted a systematic literature review and a comprehensive bioinformatic analysis of genes whose expression is affected by flavanols in cells defining cardiometabolic health: hepatocytes, adipocytes, endothelial cells, smooth muscle cells and immune cells. A systematic literature search was performed using the following pre-defined criteria: treatment with pure compounds and metabolites (no extracts) at low concentrations that are close to their plasma concentrations. Differentially expressed genes were analyzed using bioinformatics tools to identify gene ontologies, networks, cellular pathways and interactions, as well as transcriptional and post-transcriptional regulators. The systematic literature search identified 54 differentially expressed genes at the mRNA level in in vitro models of cardiometabolic disease exposed to flavanols and their metabolites. Global bioinformatic analysis revealed that these genes are predominantly involved in inflammation, leukocyte adhesion and transendothelial migration, and lipid metabolism. We observed that, although the investigated cells responded differentially to flavanol exposure, the involvement of anti-inflammatory responses is a common mechanism of flavanol action. We also identified potential transcriptional regulators of gene expression: transcriptional factors, such as GATA2, NFKB1, FOXC1 or PPARG, and post-transcriptional regulators: miRNAs, such as mir-335-5p, let-7b-5p, mir-26b-5p or mir-16-5p. In parallel, we analyzed the nutrigenomic effects of flavanols in intestinal cells and demonstrated their predominant involvement in the metabolism of circulating lipoproteins. In conclusion, the results of this systematic analysis of the nutrigenomic effects of flavanols provide a more comprehensive picture of their molecular mechanisms of action and will support the future setup of genetic studies to pave the way for individualized dietary recommendations. This journal i