Estrogen Receptor α Participates to the Beneficial Effect of Red Wine Polyphenols in a Mouse Model of Obesity-Related Disorders

Beneficial Effects of Red Wine Polyphenols on Human Health: Comprehensive Review

Polyphenols are secondary plant metabolites synthesized during the development of the grape berry as a response to stress conditions. They are important constituents in red wines that contribute to the sensory properties and antioxidant activity of wines. Due to the development of highly sophisticated analytical devices, it is now possible to characterize the structure of highly polymerized polyphenols and obtain a full polyphenol profile of red wines. Red wine polyphenols include the ones present in grapes as well as new polyphenol products formed during the winemaking process. Among them, the most important groups and their representatives are flavanols (catechin), stilbenes (trans-resveratrol), flavonols (quercetin) and hydroxybenzoic acids (gallic acid). It is known that polyphenols exhibit beneficial effects on human health, such as anti-inflammatory, anticarcinogenic and cardio-protective effects. Many studies have been conducted on the health effects of red wine polyphenols in cancer chemopreventive activities, neuroprotective effects and impact on cardiovascular diseases, gut microbiota in humans, etc. This review will provide major scientific findings on the impact of red wine polyphenols on human health as well as a review of polyphenols present in red wines and their main features.

Recent advances in polysaccharides stabilized emulsions for encapsulation and delivery of bioactive food ingredients: A review

Many bioactive food ingredients were encapsulated in different forms to improve their stability and bioavailability. Emulsions have showed excellent properties in encapsulation, controlled release, and targeted delivery of bioactives. Polysaccharides are widely available and have different structures with different advantages including non-toxic, easily digested, biocompatible and can keep stable over a wide range of pH and temperatures. In this review, the most common polysaccharides and polysaccharide based complexes as emulsifiers to stabilize emulsions in recent ten years are described. The close relationships between the types and structures of polysaccharides and their emulsifying capacities are discussed. In addition, the absorption and bioavailability of bioactive food components loaded in polysaccharide stabilized emulsions are summarized. The main goal of the review is to emphasize the important roles of polysaccharides in stabilizing emulsions. Moreover, speculations regarded to some issues for the further exploration and possible onward developments of polysaccharides stabilized emulsions are also discussed.

Ethanol Extract of Leaves of Cassia siamea Lam Protects against Diabetes-Induced Insulin Resistance, Hepatic, and Endothelial Dysfunctions in ob/ob Mice

Despite long traditional utilization and some reports on the antihyperglycemic and antihyperlipidemic action of Cassia siamea, the mechanisms involved have not been investigated yet. Thus, the objective of the present study was to investigate whether and how oral administration of the ethanolic extract of Cassia siamea Lam leaves (LECS) improves glucose and insulin homoeostasis, liver damage, and endothelial dysfunction in an experimental model of type 2 diabetes, the leptin-deficient ob/ob mice. Oxidative stress and protein expression of insulin-dependent and insulin -independent signaling pathways were studied. Obese (ob/ob) vs. control (ob/+) mice were treated daily with intragastric administration of either vehicle or LECS (200 mg/kg, per day) for 4 weeks. Fasting blood glucose, body weight, food intake, glucose and insulin tolerance, oxidative stress, and liver damage as well as vascular complications with respect to endothelial dysfunction were examined. Administration of LECS in obese mice significantly reduced blood glucose and insulin levels, improved glucose tolerance and insulin sensitivity, and restored the increase of circulating AST and ALT without modification of body weight and food intake. These effects were associated with increased activity of both insulin and AMPK pathways in the liver and skeletal muscles. Of particular interest, administration of LECS in obese mice completely prevented the endothelial dysfunction resulting from an increased NO^· and decreased reactive oxygen species (ROS) production in the aorta. Altogether, oral administration of LECS remarkably attenuates features of type 2 diabetes on glucose, hepatic inflammation, insulin resistance, endothelial function, and vascular oxidative stress, being as most of these effects are related to insulin-dependent and insulin-independent mechanisms. Therefore, this study points for the therapeutic potential of Cassia siamea in correcting both metabolic and vascular alterations linked to type 2 diabetes.

Electron Paramagnetic Resonance Measurements of Reactive Oxygen Species by Cyclic Hydroxylamine Spin Probes

SIGNIFICANCE

Oxidative stress contributes to numerous pathophysiological conditions such as development of cancer, neurodegenerative, and cardiovascular diseases. A variety of measurements of oxidative stress markers in biological systems have been developed; however, many of these methods are not specific, can produce artifacts, and do not directly detect the free radicals and reactive oxygen species (ROS) that cause oxidative stress. Electron paramagnetic resonance (EPR) is a unique tool that allows direct measurements of free radical species. Cyclic hydroxylamines are useful and convenient molecular probes that readily react with ROS to produce stable nitroxide radicals, which can be quantitatively measured by EPR. In this work, we critically review recent applications of various cyclic hydroxylamine spin probes in biology to study oxidative stress, their advantages, and the shortcomings. Recent Advances: In the past decade, a number of new cyclic hydroxylamine spin probes have been developed and their successful application for ROS measurement using EPR has been published. These new state-of-the-art methods provide improved selectivity and sensitivity for in vitro and in vivo studies.

CRITICAL ISSUES

Although cyclic hydroxylamine spin probes EPR application has been previously described, there has been lack of translation of these new methods into biomedical research, limiting their widespread use. This work summarizes "best practice" in applications of cyclic hydroxylamine spin probes to assist with EPR studies of oxidative stress.

FUTURE DIRECTIONS

Additional studies to advance hydroxylamine spin probes from the "basic science" to biomedical applications are needed and could lead to better understanding of pathological conditions associated with oxidative stress. Antioxid. Redox Signal. 28, 1433-1443.

Extract Enriched in Flavan-3-ols and Mainly Procyanidin Dimers Improves Metabolic Alterations in a Mouse Model of Obesity-Related Disorders Partially via Estrogen Receptor Alpha

Red wine polyphenol extracts improve cardiovascular and metabolic disorders linked to obesity. Their vascular protection is mediated by the activation of the alpha isoform of the estrogen receptor (ERα). In the present study, we explored the effects of a grape seed extract (GSE) enriched in the flavan-3-ols procyanidin dimers on obesity-related cardiovascular and metabolic disorders; with a particular interest in the role/contribution of ERα. Ovariectomized wild type or ERα knockout (KO) mice were fed with standard or western diet, supplemented or not with GSE, for 12 weeks. Their body weight was monitored throughout the study, and an echocardiography was performed at the end of the treatment. Blood and tissues were collected for biochemical and functional analysis, including nitric oxide and oxidative stress measurement. Vascular reactivity and liver mitochondrial complexes activity were also analyzed. In western diet-fed mice, GSE reduced adiposity, plasma triglycerides, and oxidative stress in the heart, liver, adipose and skeletal tissues; but did not improve the vascular dysfunction. In western diet-fed mice, ERα deletion prevented or reduced the beneficial effects of GSE on plasma triglycerides and visceral adiposity. ERα deletion also prevented/reduced the anti-oxidant effect of GSE in the liver, but did not affect its capacity to reduce oxidative stress in the heart and adipose tissue. In conclusion, dietary supplementation of GSE attenuated features of metabolic syndrome partially through ERα-dependent mechanisms. This report highlights the therapeutic potential of polyphenols, and especially extract enriched in procyanidin dimers, against the metabolic disorders associated with excessive energy intake.

High-throughput sequencing of microbial community diversity in soil, grapes, leaves, grape juice and wine of grapevine from China

In this study Illumina MiSeq was performed to investigate microbial diversity in soil, leaves, grape, grape juice and wine. A total of 1,043,102 fungal Internal Transcribed Spacer (ITS) reads and 2,422,188 high quality bacterial 16S rDNA sequences were used for taxonomic classification, revealed five fungal and eight bacterial phyla. At the genus level, the dominant fungi were Ascomycota, Sordariales, Tetracladium and Geomyces in soil, Aureobasidium and Pleosporaceae in grapes leaves, Aureobasidium in grape and grape juice. The dominant bacteria were Kaistobacter, Arthrobacter, Skermanella and Sphingomonas in soil, Pseudomonas, Acinetobacter and Kaistobacter in grape and grapes leaves, and Oenococcus in grape juice and wine. Principal coordinate analysis showed structural separation between the composition of fungi and bacteria in all samples. This is the first study to understand microbiome population in soil, grape, grapes leaves, grape juice and wine in Xinjiang through High-throughput Sequencing and identify microorganisms like Saccharomyces cerevisiae and Oenococcus spp. that may contribute to the quality and flavor of wine.