Effects of dietary polyphenols on neuroregulatory factors and pathways that mediate food intake and energy regulation in obesity

Four glycosyltransferase genes are responsible for synthesis and accumulation of different flavonol glycosides in apple tissues

Flavonols are widely synthesized throughout the plant kingdom, playing essential roles in plant physiology and providing unique health benefits for humans. Their glycosylation plays significant role in improving their stability and solubility, thus their accumulation and function. However, the genes encoding the enzymes catalyze this glycosylation remain largely unknown in apple. This study utilized a combination of methods to identify genes encoding such enzymes. Initially, candidate genes were selected based on their potential to encode UDP-dependent glycosyltransferases (UGTs) and their expression patterns in response to light induction. Subsequently, through testing the in vitro enzyme activity of the proteins produced in Escherichia coli cells, four candidates were confirmed to encode a flavonol 3-O-galactosyltransferase (UGT78T6), flavonol 3-O-glucosyltransferase (UGT78S1), flavonol 3-O-xylosyltransferase/arabinosyltransferase (UGT78T5), and flavonol 3-O-rhamnosyltransferase (UGT76AE22), respectively. Further validation of these genes' functions was conducted by modulating their expression levels in stably transformed apple plants. As anticipated, a positive correlation was observed between the expression levels of these genes and the content of specific flavonol glycosides corresponding to each gene. Moreover, overexpression of a flavonol synthase gene, MdFLS, resulted in increased flavonol glycoside content in apple roots and leaves. These findings provide valuable insights for breeding programs aimed at enriching apple flesh with flavonols and for identifying flavonol 3-O-glycosyltransferases of other plant species.

Strategic exploration of whole grain cereals in modulating the glycaemic response

In the current context, diabetes presents itself as a widespread and complex global health issue. This study explores the significant influence of food microstructure and food matrix components interaction (protein, lipid, polyphenols, etc.) on the starch digestibility and the glycaemic response of post-prandial glycemia, focusing on the potential effectiveness of incorporating bioactive components from whole grain cereals into dietary strategies for the management and potential prevention of diabetes. This study aims to integrate the regulation of postprandial glycaemic homeostasis, including the complexities of starch digestion, the significant potential of bioactive whole grain components and the impact of food processing, to develop a comprehensive framework that combines these elements into a strategic approach to diabetes nutrition. The convergence of these nutritional strategies is analyzed in the context of various prevalent dietary patterns, with the objective of creating an accessible approach to mitigate and prevent diabetes. The objective remains to coalesce these nutritional paradigms into a coherent strategy that not only addresses the current public health crisis but also threads a preventative approach to mitigate future prevalence and impact.

Flavonoids, gut microbiota, and host lipid metabolism

Flavonoids are widely distributed in nature and have a variety of beneficial biological effects, including antioxidant, anti-inflammatory, and anti-obesity effects. All of these are related to gut microbiota, and flavonoids also serve as a bridge between the host and gut microbiota. Flavonoids are commonly used to modify the composition of the gut microbiota by promoting or inhibiting specific microbial species within the gut, as well as modifying their metabolites. In turn, the gut microbiota extensively metabolizes flavonoids. Hence, this reciprocal relationship between flavonoids and the gut microbiota may play a crucial role in maintaining the balance and functionality of the metabolism system. In this review, we mainly highlighted the biological effects of antioxidant, anti-inflammatory and antiobesity, and discussed the interaction between flavonoids, gut microbiota and lipid metabolism, and elaborated the potential mechanisms on host lipid metabolism.

Designing healthier and more sustainable ultraprocessed foods

The food industry has been extremely successful in creating a broad range of delicious, affordable, convenient, and safe food and beverage products. However, many of these products are considered to be ultraprocessed foods (UPFs) that contain ingredients and are processed in a manner that may cause adverse health effects. This review article introduces the concept of UPFs and briefly discusses food products that fall into this category, including beverages, baked goods, snacks, confectionary, prepared meals, dressings, sauces, spreads, and processed meat and meat analogs. It then discusses correlations between consumption levels of UPFs and diet-related chronic diseases, such as obesity and diabetes. The different reasons for the proposed ability of UPFs to increase the risk of these chronic diseases are then critically assessed, including displacement of whole foods, high energy densities, missing phytochemicals, contamination with packaging chemicals, hyperpalatability, harmful additives, rapid ingestion and digestion, and toxic reaction products. Then, potential strategies to overcome the current problems with UPFs are presented, including reducing energy density, balancing nutritional profile, fortification, increasing satiety response, modulating mastication and digestion, reengineering food structure, and precision processing. The central argument is that it may be possible to reformulate and reengineer many UPFs to improve their healthiness and sustainability, although this still needs to be proved using rigorous scientific studies.

Chaenomeles sinensis (Thouin) Koehne fruit polyphenols alleviate high-fat diet-induced obesity and liver steatosis by improving lipid metabolism in mice

Chaenomeles sinensis (Thouin) Koehne fruit is a rich source of medicinally and nutritionally important natural phytochemicals that benefit human health. Based on the information provided, we hypothesized that Chaenomeles sinensis (Thouin) Koehne fruit polyphenols (CSFP) possessed in vivo protective effect of on high-fat diet (HFD)-induced obesity and hepatic steatosis. Specific pathogen-free male C57BL/6J mice were randomly divided into 3 groups and fed with a low-fat diet, HFD, or HFD supplemented with CSFP by intragastric administration for 14 weeks. Obesity-related biochemical indexes and hepatic gene expression profile were determined. The findings of this study demonstrated notable reductions in body weight gain, serum triglycerides, total cholesterol, low-density lipoprotein cholesterol, and steatosis grade in the group supplemented with CSFP compared with the HFD group. Gene expression analysis provided insights into the molecular mechanisms, demonstrating that CSFP downregulated the expression of key genes involved in lipogenesis (e.g., Fas, Fads2, Scd1) and upregulated the genes associated with fatty acid oxidation (e.g., Pparα, Cpt1a, Acox1), while also suppressing genes implicated in cholesterol homeostasis (e.g., HMGCoR, Insig1, AdipoR2). These molecular changes suggest that CSFP exerts protective effects by modulating hepatic lipid metabolism pathways, thereby mitigating the metabolic derangements associated with HFD-induced obesity and hepatic steatosis.

The Potential Effects of Dietary Antioxidants in Obesity: A Comprehensive Review of the Literature

Obesity has become a global health concern, with its prevalence steadily increasing in recent decades. It is associated with numerous health complications, including cardiovascular diseases, diabetes, and certain types of cancer. The aetiology of obesity is multifactorial, involving genetic, environmental, and lifestyle factors. In recent years, oxidative stress has emerged as a potential contributor to obesity and its related metabolic disorders. Dietary antioxidants, which can counteract oxidative stress, have gained significant attention for their potential role in preventing and managing obesity. This comprehensive review aims to explore the impact of dietary antioxidants on obesity and its associated metabolic dysregulations, discussing the underlying mechanisms and highlighting the potential therapeutic implications.

Plant-Derived Polyphenols to Prevent and Treat Oral Mucositis Induced by Chemo- and Radiotherapy in Head and Neck Cancers Management

Oral Mucositis (OM) is the most common side effect due to chemotherapy and radiotherapy, which are the conventional treatment options for head and neck cancers. OM is a severe inflammatory condition characterized by multifactorial etiopathogenesis. It further negatively affects patients' quality of life by severe impairment of normal oral functions. Consequently, it is mandatory to identify new effective therapeutic approaches to both prevent and treat OM while also avoiding any recurrence. Polyphenols recently attracted the interest of the scientific community due to their low toxicity and wide range of biological activities making them ideal candidates for several applications in the odontostomatological field, particularly against OM. This review collects the in vivo studies and the clinical trials conducted over the past 13 years evaluating the preventive and curative effects of several polyphenolic compounds towards chemo- and radiotherapy-induced OM, both when administered alone or as a plant-extracted phytocomplex. The literature fully confirms the usefulness of these molecules, thus opening the possibility of their clinical application. However, polyphenol limitations (e.g., unfavourable physicochemical properties and susceptibility to degradation) have emerged. Consequently, the interest of the scientific community should be focused on developing innovative delivery systems able to stabilize polyphenols, thus facilitating topical administration and maximizing their efficacy.

Unravelling Effects of Rosemary (Rosmarinus officinalis L.) Extract on Hepatic Fat Accumulation and Plasma Lipid Profile in Rats Fed a High-Fat Western-Style Diet

The objective of the study was to investigate the preventive effect on obesity-related conditions of rosemary (Rosmarinus officinalis L.) extract (RE) in young, healthy rats fed a high-fat Western-style diet to complement the existing knowledge gap concerning the anti-obesity effects of RE in vivo. Sprague Dawley rats (71.3 ± 0.46 g) were fed a high-fat Western-style diet (WD) or WD containing either 1 g/kg feed or 4 g/kg feed RE for six weeks. A group fed standard chow served as a negative control. The treatments did not affect body weight; however, the liver fat percentage was reduced in rats fed RE, and NMR analyses of liver tissue indicated that total cholesterol and triglycerides in the liver were reduced. In plasma, HDL cholesterol was increased while triglycerides were decreased. Rats fed high RE had significantly increased fasting plasma concentrations of Glucagon-like peptide-1 (GLP-1). Proteomics analyses of liver tissue showed that RE increased enzymes involved in fatty acid oxidation, possibly associated with the higher fasting GLP-1 levels, which may explain the improvement of the overall lipid profile and hepatic fat accumulation. Furthermore, high levels of succinic acid in the cecal content of RE-treated animals suggested a modulation of the microbiota composition. In conclusion, our results suggest that RE may alleviate the effects of consuming a high-fat diet through increased GLP-1 secretion and changes in microbiota composition.

Polyphenols as potential enhancers of stem cell therapy against neurodegeneration

The potential of polyphenols for treating chronic-degenerative diseases (particularly neurodegenerative diseases) is attractive. However, the selection of the best polyphenol for each treatment, the mechanisms by which they act, and their efficacy are frequently discussed. In this review, the basics and the advances in the field, as well as suggestions for using natural and synthetic polyphenols alone or in a combinatorial strategy with stem cell assays, are compiled and discussed. Thus, stem cells exhibit several responses when polyphenols are added to their environment, which could provide us with knowledge for advancing the elucidation of the origin of neurodegeneration. But also, polyphenols are being included in the innovative strategies of novel therapies for treating neurodegenerative diseases as well as metabolic diseases related to neurodegeneration. In this regard, flavonoid compounds are suggested as the best natural polyphenols due to their several mechanisms for acting in ameliorative effects; but increasing reports are involving other polyphenols. Even if some facts limiting bioactivity prevent them from conventional use, some natural polyphenols and derivatives hold the promise for being improved compounds, judged by their induced effects. The current results suggest polyphenols as enhancers of stem cell therapy against the targeted diseases.

Natural polyphenols: a potential prevention and treatment strategy for metabolic syndrome

Metabolic syndrome (MS) is the term for a combination of hypertension, dyslipidemia, insulin resistance, and central obesity as factors leading to cardiovascular and metabolic disease. Epidemiological investigation has shown that polyphenol intake is negatively correlated with the incidence of MS. Natural polyphenols are widely found in cocoa beans, tea, vegetables, fruits, and some Chinese herbal medicines; they are a class of plant compounds containing a variety of phenolic structural units, which are potent antioxidants and anti-inflammatory agents in plants. Polyphenols are composed of flavonoids (such as flavanols, anthocyanidins, anthocyanins, isoflavones, etc.) and non-flavonoids (such as phenolic acids, stilbenes, and lignans). Modern pharmacological studies have proved that polyphenols can reduce blood pressure, improve lipid metabolism, lower blood glucose, and reduce body weight, thereby preventing and improving MS. Due to the unique characteristics and potential development and application value of polyphenols, this review summarizes some natural polyphenols that could treat MS, including their chemical properties, plant sources, and pharmacological action against MS, to provide a basis for the further study of polyphenols in MS.

Regulation of appetite-related neuropeptides by Panax ginseng: A novel approach for obesity treatment

Obesity is a primary factor provoking various chronic disorders, including cardiovascular disease, diabetes, and cancer, and causes the death of 2.8 million individuals each year. Diet, physical activity, medications, and surgery are the main therapies for overweightness and obesity. During weight loss therapy, a decrease in energy stores activates appetite signaling pathways under the regulation of neuropeptides, including anorexigenic [corticotropin-releasing hormone, proopiomelanocortin (POMC), cholecystokinin (CCK), and cocaine- and amphetamine-regulated transcript] and orexigenic [agouti-related protein (AgRP), neuropeptide Y (NPY), and melanin-concentrating hormone] neuropeptides, which increase food intake and lead to failure in attaining weight loss goals. Ginseng and ginsenosides reverse these signaling pathways by suppressing orexigenic neuropeptides (NPY and AgRP) and provoking anorexigenic neuropeptides (CCK and POMC), which prevent the increase in food intake. Moreover, the results of network pharmacology analysis have revealed that constituents of ginseng radix, including campesterol, beta-elemene, ginsenoside Rb1, biotin, and pantothenic acid, are highly correlated with neuropeptide genes that regulate energy balance and food intake, including ADIPOQ, NAMPT, UBL5, NUCB2, LEP, CCK, GAST, IGF1, RLN1, PENK, PDYN, and POMC. Based on previous studies and network pharmacology analysis data, ginseng and its compounds may be a potent source for obesity treatment by regulating neuropeptides associated with appetite.

Effects of Concord grape juice flavor intensity and phenolic compound content on glycemia, appetite and cognitive function in adults with excess body weight: a randomized double-blind crossover trial

Background & aims: Concord grape (Vitis lambrusca) juice (CGJ) contains a unique combination of polyphenolic compounds with diverse effects on human health. It also has an intense sensory profile that may modify food choice. Daily consumption of CGJ over 8 weeks reduced fasting blood glucose. However, the impact on 24h-postprandial glucose response from CGJ is still not clear. The purpose of this study was to assess the effect of CGJ flavor intensity and phenolic content on 24 h postprandial glucose concentrations, appetitive sensations, and cognitive function in adults with excess body weight when consumed alone or with a meal. Methods: In a randomized, double-blind, crossover design study, participants consumed three types of beverages: 100% CGJ, a polyphenol-free grape flavored drink with the same flavor essence (LP) or a polyphenol-free grape flavored drink with reduced flavor essence (LPF) either without (trial I) or with (trial II) a meal. 24 h glucose was measured through continuous glucose monitoring. Phenolic metabolite excretion was assessed in 24 h urine samples. Appetite (hunger, thirst, fullness, desire to eat, and prospective consumption) and cognitive function (alertness, energetic, strength, calmness, and relaxation) were assessed hourly through visual analog scales. Results: Thirty-four adults completed trial I and 34 adults completed trial II. When consumed with a meal, beverages with customary flavor essence (CGJ and LP) reduced hunger, desire to eat, and prospective consumption and consumption of the polyphenol-free reduced flavor essence beverage was associated with higher 24 h glucose _tAUC. No consistent effects were observed for cognitive outcomes. When consumed alone, CGJ was related to lower glycemic responses by those excreting a higher concentration of the phenolic metabolite iso/ferulic-3'-O-glucuronide, but in beverages without CG phenolics and reduced flavor essence, glycemia was higher among those excreting higher concentrations of caffeic acid-O-sulfate. Conclusions: Both natural phenolics and flavor essence of CGJ may help to moderate appetite and glycemia. Clinical Trials registered at http://www.clinicaltrials.gov: NCT03409484 (trial I) and NCT03409497 (trial II).

Appetite and Satiety Effects of the Acute and Regular Consumption of Green Coffee Phenols and Green Coffee Phenol/Oat β-Glucan Nutraceuticals in Subjects with Overweight and Obesity

Green coffee has weight management properties, yet its effects on appetite and satiety remain unclear as few, mainly acute, studies perform objective measurements. Therefore, the influence on appetite/satiety of acute and regular consumption of two nutraceuticals, a decaffeinated green coffee phenolic extract (GC) alone or combined with oat β-glucans (GC/BG), with known satiating properties, has been analysed subjectively using visual analog scales (VAS) and objectively measuring actual food intake and postprandial appetite and satiety hormones. A randomised, cross-over, blind trial was carried out in 29 overweight volunteers who consumed GC or GC/BG twice a day for 8 weeks. After acute (day = 0) and regular consumption (day = 56) of the nutraceuticals, satiety was measured at 30, 60, 90, 150, and 210 min, as well as food intake at breakfast (30 min) and lunch (300 min). Additionally, in a subgroup of participants (n = 9), cholecystokinin, peptide-YY, glucagon-like-peptide-1, ghrelin and leptin concentrations were analysed in blood samples taken at the same time-points. According to VAS results, GC/BG reduced hunger more efficiently than GC. However, there were no statistically significant differences in food intake. Comparing the effects of the acute consumption of GC/BG and GC, leptin concentration at 150 min was higher after GC/BG intake vs. GC. Moreover, when comparing the effects of regularly consuming the two nutraceuticals, maximum ghrelin level decreased with GC/BG vs. GC. In conclusion, acute and regular effects of the nutraceuticals on appetite/satiety differed, and subjective and objective results partially agreed; GC/BG may reduce hunger more efficiently than GC.

Sub-chronic consumption of a phenolic-rich avocado paste extract induces GLP-1-, leptin-, and adiponectin-mediated satiety in Wistar rats

Avocado paste (AP) is a phenolic-rich byproduct of avocado oil extraction. The effects of sub-chronic consumption of diets supplemented with an AP phenolic extract (PE) were analyzed. A standard diet (SD), high-fat diet (HFD), and these supplemented with PE (SD + PE and HFD + PE) were used. Significantly increased satiety was observed in PE-supplemented groups, according to less food consumption (-15% in SD + PE vs. SD, and -11% in HFD + PE vs. HFD), without changes in weight gain or percentage of adipose tissue. PE-supplemented groups had an increased plasma concentration ( + 16% in SD + PE vs. SD, and +26% in HFD + PE vs. HFD) and relative mRNA expression (+74% in SD + PE vs. SD, and +46% in HFD + PE vs. HFD) of GLP-1; an increase in plasma leptin and adiponectin was independent of their mRNA expression. Our results suggest that AP-derived PE exerts a satiety effect in vivo, possibly mediated by GLP-1, leptin, and adiponectin. PRACTICAL APPLICATIONS: Minimizing food waste is a top priority in most of the world, thus, researchers seek methods to reintroduce industrial fruit and vegetable byproducts into the food processing chain. The present work highlights the potential of avocado byproducts as sources of bioactive phenolic compounds, whose sub-chronic consumption (8 weeks) exerts a satiety action in vivo. Avocado farming is resource-intensive, making it of relevance to producers and processing industries to avoid discarding its byproducts as much as possible.

Different Protein Sources in the Maternal Diet of the Rat during Gestation and Lactation Affect Milk Composition and Male Offspring Development during Adulthood

Protein sources in maternal diet are important for mammary gland differentiation and milk protein; however, few studies have examined the metabolic and cellular adaptations of mothers based on protein source diets during pregnancy and lactation, and leptin concentration in offspring. We evaluated metabolic parameters and maternal key organs and milk components in mothers at the end of lactation, who were fed different sources of proteins. In postnatal day 110 and 250, we studied development parameters and leptin in male offspring. Female rats received a Vegetal (V) or Animal (A) diet during pregnancy and lactation. After weaning, male offspring ate V diet until postnatal day 250, which yielded two groups: Vv and Av. Milk dry, protein and fat were analyzed. Maternal metabolic parameters, leptin, and liver, adipose tissue and mammary gland histological analyses were studied. Body weight, food intake and leptin were analyzed in offspring at two ages. Adipose tissue weight and cells size and liver fat, mammary gland apoptosis, weight, milk protein and leptin were higher in A vs V. Maternal liver and milk dry were lower in A vs V. All offspring parameters were higher in Av vs Vv at postnatal day 110; however, at postnatal day 250, leptin was higher in Av vs Vv. Maternal serum and milk leptin had a positive correlation with offspring serum leptin at both ages. Consumption of animal protein-based diets by mothers during developmental periods affects specific maternal organs and changes milk composition during lactation, leading to a hyperleptinemic phenotype in male offsprings.

The anti-obesogenic effects of dietary berry fruits: A review

The prevalence of obesity in the world is fearsomely climbing, which has brought about heavy threats on human health and economic development. For coping with this problem, researchers have looked at the profound potentials of natural products for resolving obesity because of their high efficiencies and few undesirable outcomes in the recent years. Berry fruits are huge reservoirs of bioactive components, and their anti-obesity potentials are arousing much interests. In this review, the current main strategies to manage obesity were summarized, including inhibiting appetite and lowering the food intake, improving energy expenditure and thermogenesis, suppressing absorption and digestion, reducing lipid synthesis and storage as well as modulating composition of gut microbiota. In addition, this review discussed the potentials of dietary berry fruits (blueberries, cranberries, raspberries, strawberries, mulberries, lingonberries, blackberries, black chokeberries, elderberries, bilberries, grape, blackcurrants, jaboticabas, red bayberries, sea-buckthorns, goldenberries and goji berries) to counteract obesity or obesity-associated complications based on recent animal experiments and human studies. Then, the bioaccessibility of phenolic compounds present in berry fruits was discussed. On the other hand, several challenges including securing effective dosage, further understanding their interaction with human tissues, improving bioavailability and protection of functional ingredients during delivery should be taken into account and conquered in the coming years.

The Microbiota and the Gut-Brain Axis in Controlling Food Intake and Energy Homeostasis

Obesity currently represents a major societal and health challenge worldwide. Its prevalence has reached epidemic proportions and trends continue to rise, reflecting the need for more effective preventive measures. Hypothalamic circuits that control energy homeostasis in response to food intake are interesting targets for body-weight management, for example, through interventions that reinforce the gut-to-brain nutrient signalling, whose malfunction contributes to obesity. Gut microbiota-diet interactions might interfere in nutrient sensing and signalling from the gut to the brain, where the information is processed to control energy homeostasis. This gut microbiota-brain crosstalk is mediated by metabolites, mainly short chain fatty acids, secondary bile acids or amino acids-derived metabolites and subcellular bacterial components. These activate gut-endocrine and/or neural-mediated pathways or pass to systemic circulation and then reach the brain. Feeding time and dietary composition are the main drivers of the gut microbiota structure and function. Therefore, aberrant feeding patterns or unhealthy diets might alter gut microbiota-diet interactions and modify nutrient availability and/or microbial ligands transmitting information from the gut to the brain in response to food intake, thus impairing energy homeostasis. Herein, we update the scientific evidence supporting that gut microbiota is a source of novel dietary and non-dietary biological products that may beneficially regulate gut-to-brain communication and, thus, improve metabolic health. Additionally, we evaluate how the feeding time and dietary composition modulate the gut microbiota and, thereby, the intraluminal availability of these biological products with potential effects on energy homeostasis. The review also identifies knowledge gaps and the advances required to clinically apply microbiome-based strategies to improve the gut-brain axis function and, thus, combat obesity.

Diet-Derived Antioxidants and Their Role in Inflammation, Obesity and Gut Microbiota Modulation

It is generally accepted that gut microbiota, inflammation and obesity are linked to the development of cardiovascular diseases and other chronic/non-communicable pathological conditions, including cancer, neurodegenerative diseases and ageing-related disorders. In this scenario, oxidative stress plays a pivotal role. Evidence suggests that the global dietary patterns may represent a tool in counteracting oxidative stress, thus preventing the onset of diseases related to oxidative stress. More specifically, dietary patterns based on the regular consumption of fruits and vegetables (i.e., Mediterranean diet) have been licensed by various national nutritional guidelines in many countries for their health-promoting effects. Such patterns, indeed, result in being rich in specific components, such as fiber, minerals, vitamins and antioxidants, whose beneficial effects on human health have been widely reported. This suggests a potential nutraceutical power of specific dietary components. In this manuscript, we summarize the most relevant evidence reporting the impact of dietary antioxidants on gut microbiota composition, inflammation and obesity, and we underline that antioxidants are implicated in a complex interplay between gut microbiota, inflammation and obesity, thus suggesting their possible role in the development and modulation of chronic diseases related to oxidative stress and in the maintenance of wellness. Do all roads lead to Rome?

Dietary Polyphenols to Combat Nonalcoholic Fatty Liver Disease via the Gut-Brain-Liver Axis: A Review of Possible Mechanisms

Polyphenols are a group of micronutrients widely existing in plant foods including fruits, vegetables, and teas that can improve nonalcoholic fatty liver disease (NAFLD). In this review, the existing knowledge of dietary polyphenols for the development of NAFLD regulated by intestinal microecology is discussed. Polyphenols can influence the vagal afferent pathway in the central and enteric nervous system to control NAFLD via gut-brain-liver cross-talk. The possible mechanisms involve in the alteration of microbial community structure, effects of gut metabolites (short-chain fatty acids (SCFAs), bile acids (BAs), endogenous ethanol (EnEth)), and stimulation of gut-derived hormones (ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and leptin) based on the targets excavated from the gut-brain-liver axis. Consequently, the communication among the intestine, brain, and liver paves the way for new approaches to understand the underlying roles and mechanisms of dietary polyphenols in NAFLD pathology.

Dietary Luteolin: A Narrative Review Focusing on Its Pharmacokinetic Properties and Effects on Glycolipid Metabolism

Luteolin, a flavone subclass of flavonoids, is commonly found in food plants and has multiple biological activities. Recently, evidence is growing with regard to the potential of luteolin intake to beneficially affect glycolipid metabolism disorders (GLMDs), particularly insulin resistance, diabetes, and obesity. The aim of this contribution is to provide an overview of recent advances in identifying and understanding the pharmacokinetic properties (absorption, metabolism, and bioavailability) of luteolin, its regulatory effects on glycolipid metabolism, and the underlying mechanisms of action of luteolin in the brain, liver, adipose tissues, and other tissues/organs. Collectively, luteolin or its principal metabolites may contribute to counteracting GLMDs, especially for human obesity and diabetes.

Health Effects of Grape Seed and Skin Extracts and Their Influence on Biochemical Markers

This review is focused on the study of the effects of grape seed and skin extract (GSSE) on human health. GSSE contains high concentrations of important polyphenolic substances with high biological activity. This review is a summary of studies that investigate the effects of GSSE on diabetes mellitus, cardiovascular disease and cancer, its neuroprotective effect, and its effects on the gastrointestinal tract and other health complications related to these diseases. The results of the studies confirm that the anti-inflammatory, antiapoptotic, and pro-proliferative effects of “Vitis vinifera L.” seed extract reduce the level of oxidative stress and improve the overall lipid metabolism.

Polyphenolic Profiling of Forestry Waste by UPLC-HDMSE

Polyphenols constitute a diverse array of naturally occurring secondary metabolites found in plants which, when consumed, have been shown to promote human health. Greater consumption may therefore aid in the fight against diseases such as obesity, diabetes, heart disease, cancer, etc. Tree bark is polyphenol-rich and has potential to be used in food supplements. However, it is important to gain insight into the polyphenol profile of different barks to select the material with greatest concentration and diversity. Ultra-performance liquid chromatography (UPLC) was coupled with an ion mobility time-of-flight high-definition/high-resolution mass spectrometer (UPLC-HDMSE) to profile ethanol extracts of three common tree barks (Pinus contorta, Pinus sylvestris, Quercus robur) alongside a commercial reference (Pycnogenol® extracted from Pinus pinaster). Through the use of Progenesis QI informatics software, 35 high scoring components with reported significance to health were tentatively identified across the three bark extracts following broadly the profile of Pycnogenol®. Scots Pine had generally higher compound abundances than in the other two extracts. Oak bark extract showed the lowest abundances but exhibited higher amounts of naringenin and 3-O-methylrosmarinic acid. We conclude that forestry bark waste provides a rich source of extractable polyphenols suitable for use in food supplements and so can valorise this forestry waste stream.

A grape seed extract maternal dietary supplementation in reproductive hens reduces oxidative stress associated to modulation of plasma and tissue adipokines expression and improves viability of offsprings

In reproductive hens, a feed restriction is an usual practice to improve metabolic and reproductive disorders. However, it acts a stressor on the animal. In mammals, grape seed extracts (GSE) reduces oxidative stress. However, their effect on endocrine and tissue response need to be deepened in reproductive hens. Here, we evaluated the effects of time and level of GSE dietary supplementation on growth performance, viability, oxidative stress and metabolic parameters in plasma and metabolic tissues in reproductive hens and their offsprings. We designed an in vivo trial using 4 groups of feed restricted hens: A (control), B and C (supplemented with 0.5% and 1% of the total diet composition in GSE since week 4, respectively) and D (supplemented with 1% of GSE since the hatch). In hens from hatch to week 40, GSE supplementation did not affect food intake and fattening whatever the time and dose of supplementation. Body weight was significantly reduced in D group as compared to control. In all hen groups, GSE supplementation decreased plasma oxidative stress index associated to a decrease in the mRNA expression of the NOX4 and 5 oxidant genes in liver and muscle and an increase in SOD mRNA expression. This was also associated to decreased plasma chemerin and increased plasma adiponectin and visfatin levels. Interestingly, maternal GSE supplementation increased the live body weight and viability of chicks at hatching and 10 days of age. This was associated to a decrease in plasma and liver oxidative stress parameters. Taken together, GSE maternal dietary supplementation reduces plasma and tissue oxidative stress associated to modulation of adipokines without affecting fattening in reproductive hens. A 1% GSE maternal dietary supplementation increased offspring viability and reduced oxidative stress suggesting a beneficial transgenerational effect and a potential use to improve the quality of the progeny in reproductive hens.

Islet Amyloid Polypeptide: A Partner in Crime With Aβ in the Pathology of Alzheimer's Disease

Diabetes affects hundreds of millions of patients worldwide. Despite the advances in understanding the disease and therapeutic options, it remains a leading cause of death and of comorbidities globally. Islet amyloid polypeptide (IAPP), or amylin, is a hormone produced by pancreatic β-cells. It contributes to the maintenance of glucose physiological levels namely by inhibiting insulin and glucagon secretion as well as controlling adiposity and satiation. IAPP is a highly amyloidogenic polypeptide forming intracellular aggregates and amyloid structures that are associated with β-cell death. Data also suggest the relevance of unprocessed IAPP forms as seeding for amyloid buildup. Besides the known consequences of hyperamylinemia in the pancreas, evidence has also pointed out that IAPP has a pathological role in cognitive function. More specifically, IAPP was shown to impair the blood–brain barrier; it was also seen to interact and co-deposit with amyloid beta peptide (Aß), and possibly with Tau, within the brain of Alzheimer's disease (AD) patients, thereby contributing to diabetes-associated dementia. In fact, it has been suggested that AD results from a metabolic dysfunction in the brain, leading to its proposed designation as type 3 diabetes. Here, we have first provided a brief perspective on the IAPP amyloidogenic process and its role in diabetes and AD. We have then discussed the potential interventions for modulating IAPP proteotoxicity that can be explored for therapeutics. Finally, we have proposed the concept of a “diabetes brain phenotype” hypothesis in AD, which may help design future IAPP-centered drug developmentstrategies against AD.

Effects of Grape Seed Proanthocyanidin Extract on Obesity

Obesity is a chronic metabolic disease resulting from excessive fat accumulation and/or abnormal distribution caused by multiple factors. As a major component of metabolic syndrome, obesity is closely related to many diseases such as type 2 diabetes mellitus, hyperlipidemia, hypertension, coronary heart disease, stroke and cancer. Hence, the problem of obesity cannot be ignored, and recent studies have shown that grape seed proanthocyanidin extract (GSPE) has an antiobesity effect. This paper systematically reviews the research progress and potential mechanism of GSPE emphasizing on obesity prevention and treatment.

Glycaemic regulation, appetite and ex vivo oxidative stress in young adults following consumption of high-carbohydrate cereal bars fortified with polyphenol-rich berries

Consumption of certain berries appears to slow postprandial glucose absorption, attributable to polyphenols, which may benefit exercise and cognition, reduce appetite and/or oxidative stress. This randomised, crossover, placebo-controlled study determined whether polyphenol-rich fruits added to carbohydrate-based foods produce a dose-dependent moderation of postprandial glycaemic, glucoregulatory hormone, appetite and ex vivo oxidative stress responses. Twenty participants (eighteen males/two females; 24 (sd 5) years; BMI: 27 (sd 3) kg/m2) consumed one of five cereal bars (approximately 88 % carbohydrate) containing no fruit ingredients (reference), freeze-dried black raspberries (10 or 20 % total weight; LOW-Rasp and HIGH-Rasp, respectively) and cranberry extract (0·5 or 1 % total weight; LOW-Cran and HIGH-Cran), on trials separated by ≥5 d. Postprandial peak/nadir from baseline (Δmax) and incremental postprandial AUC over 60 and 180 min for glucose and other biochemistries were measured to examine the dose-dependent effects. Glucose AUC0-180 min trended towards being higher (43 %) after HIGH-Rasp v. LOW-Rasp (P=0·06), with no glucose differences between the raspberry and reference bars. Relative to reference, HIGH-Rasp resulted in a 17 % lower Δmax insulin, 3 % lower C-peptide (AUC0-60 min and 3 % lower glucose-dependent insulinotropic polypeptide (AUC0-180 min) P<0·05. No treatment effects were observed for the cranberry bars regarding glucose and glucoregulatory hormones, nor were there any treatment effects for either berry type regarding ex vivo oxidation, appetite-mediating hormones or appetite. Fortification with freeze-dried black raspberries (approximately 25 g, containing 1·2 g of polyphenols) seems to slightly improve the glucoregulatory hormone and glycaemic responses to a high-carbohydrate food item in young adults but did not affect appetite or oxidative stress responses at doses or with methods studied herein.

Influence of Olive Extracts on the Expression of Genes Involved in Lipid Metabolism in Medaka Fish

Aims. To assess the possible effect of polyphenol-rich olive extracts on lipid metabolism in medaka fish by quantifying the expression of lipogenic and lipolytic genes. Materials and methods. Adult medaka fish were maintained in tanks for five days with five extracts at 0.01% in water, causing obesity through a diet rich in carbohydrates, with a control group maintained in water with a normal diet. The extracts contained polyphenols ranging between 7 and 116 mg/g (oleuropein, hydroxytyrosol) with an antioxidant power of 2-13 mmol of 2,4,6-tri(2-pyridyl)-1,3,5-triazine/100 g. After five days, the fish were sacrificed and the hepatic mRNA and its complementary DNA were extracted by reverse transcription. Complementary DNAs were quantified for three lipolytic and three lipogenic genes by real-time PCR. The relative gene expression was calculated from the amplification curves in reference to the control group. Results. The expression of genes involved in lipolysis, including peroxisome proliferator-activated receptor-±, acyl-CoA oxidase 1, and carnitine palmitoyltransferase 1, were clearly decreased in fish subjected to an obesogenic diet, and this situation could not be reversed in fish maintained with polyphenol-rich extracts. In contrast, lipogenic fatty acid synthase, acetyl-CoA carboxylase 1, and sterol regulatory element-binding protein 1 genes increased considerably with the obesogenic diet and reverted to the normal state with the olive extracts. The effect was not dependent on the total polyphenol content, the specific oleuropein or hydroxytyrosol concentration, or the antioxidant power, suggesting a synergistic effect. Conclusion. Olive polyphenols, acting as anti-lipogenic agents, have a positive effect on lipid metabolism, but their mechanism in each gene is different according to the extract, which supports synergistic mechanisms with the different proportions of polyphenols and accompanying phytochemicals in each extract.

Dietary Flavonoids for Immunoregulation and Cancer: Food Design for Targeting Disease

Flavonoids, one of the most abundant phytochemicals in a diet rich in fruits and vegetables, have been recognized as possessing anti-proliferative, antioxidant, anti-inflammatory, and estrogenic activities. Numerous cellular and animal-based studies show that flavonoids can function as antioxidants by preventing DNA damage and scavenging reactive oxygen radicals, inhibiting formation of DNA adducts, enhancing DNA repair, interfering with chemical damage by induction of Phase II enzymes, and modifying signaling pathways. Recent evidence also shows their ability to regulate the immune system. However, findings from clinical trials have been mixed with no clear consensus on dose, frequency, or type of flavonoids best suited to elicit many of the beneficial effects. Delivery of these bioactive compounds to their biological targets through "targeted designed" food processing strategies is critical to reach effective concentration in vivo. Thus, the identification of novel approaches that optimize flavonoid bioavailability is essential for their successful clinical application. In this review, we discuss the relevance of increasing flavonoid bioavailability, by agricultural engineering and "targeted food design" in the context of the immune system and cancer.

Diet-induced hypothalamic dysfunction and metabolic disease, and the therapeutic potential of polyphenols

BACKGROUND

The prevalence of obesity and metabolic diseases continues to rise globally. The increased consumption of unhealthy energy-rich diets that are high in fat and sugars results in oxidative stress and inflammation leading to hypothalamic dysfunction, which has been linked with these diseases. Conversely, diets rich in polyphenols, which are phytochemicals known for their antioxidant and anti-inflammatory properties, are associated with a reduced risk for developing metabolic diseases.

SCOPE OF REVIEW

This review provides an overview of the effects of polyphenols against diet-induced hypothalamic dysfunction with respect to neural inflammation and mitochondrial dysfunction. Results show that polyphenols ameliorate oxidative stress and inflammation within the hypothalamus, thereby improving leptin signaling and mitochondrial biogenesis. Furthermore, they protect against neurodegeneration by decreasing the production of reactive oxygen species and enhancing natural antioxidant defense systems.

MAJOR CONCLUSIONS

The potential of polyphenols as nutraceuticals against hypothalamic inflammation, mitochondrial dysfunction, and neurodegeneration could hold tremendous value. With hypothalamic inflammation increasing naturally with age, the potential to modulate these processes in order to extend longevity is exciting and warrants exploration. The continued escalation of mental health disorders, which are characterized by heightened neuronal inflammation, necessitates the furthered investigation into polyphenol therapeutic usage in this regard.

Calcium Signaling Pathways: Key Pathways in the Regulation of Obesity

Nowadays, high epidemic obesity-triggered hypertension and diabetes seriously damage social public health. There is now a general consensus that the body's fat content exceeding a certain threshold can lead to obesity. Calcium ion is one of the most abundant ions in the human body. A large number of studies have shown that calcium signaling could play a major role in increasing energy consumption by enhancing the metabolism and the differentiation of adipocytes and reducing food intake through regulating neuronal excitability, thereby effectively decreasing the occurrence of obesity. In this paper, we review multiple calcium signaling pathways, including the IP3 (inositol 1,4,5-trisphosphate)-Ca²⁺ (calcium ion) pathway, the p38-MAPK (mitogen-activated protein kinase) pathway, and the calmodulin binding pathway, which are involved in biological clock, intestinal microbial activity, and nerve excitability to regulate food intake, metabolism, and differentiation of adipocytes in mammals, resulting in the improvement of obesity.

Tea Polysaccharides as Potential Therapeutic Options for Metabolic Diseases

Tea polysaccharides (TPS) are regarded as some of the main bioactive constituents of tea made from the leaves and buds of the tea plant ( Camellia sinensis L.). An increasing number of studies have demonstrated that TPS can reduce the risk of type 2 diabetes, obesity, and other metabolic diseases. However, the potential mechanisms responsible for antidiabetic and antiobesogenic activities of TPS remain unclear. Therefore, the cellular and physiological mechanisms that underlie the antidiabetic and antiobesogenic effects, including antioxidant and anti-inflammation effects, inhibition of digestive enzymes, prevention of macronutrient absorption, and expression of gene and protein, were summarized in this review. Furthermore, the gastrointestinal functions of TPS and the role of gut microbiota in the prevention and treatment of metabolic diseases were discussed. It is expected that the present review will be helpful for enhancing our knowledge about the health-promoting effects of TPS on metabolic diseases and stimulating further works on TPS.

Role of intestinal microecology in the regulation of energy metabolism by dietary polyphenols and their metabolites

Background

Polyphenols are a class of plant secondary metabolites with a variety of physiological functions. Polyphenols and their intestinal metabolites could greatly affect host energy metabolism via multiple mechanisms.

Objective

The objective of this review was to elaborate the role of intestinal microecology in the regulatory effects of dietary polyphenols and their metabolites on energy metabolism.

Methods

In this review, we illustrated the potential mechanisms of energy metabolism regulated by the crosstalk between polyphenols and intestinal microecology including intestinal microbiota, intestinal epithelial cells, and mucosal immune system.

Results

Polyphenols can selectively regulate the growth of susceptible microorganisms (eg. reducing the ratio of Firmicutes to Bacteroides, promoting the growth of beneficial bacteria and inhibiting pathogenic bacteria) as well as alter bacterial enzyme activity. Moreover, polyphenols can influence the absorption and secretion of intestinal epithelial cells, and alter the intestinal mucosal immune system.

Conclusion

The intestinal microecology play a crucial role for the regulation of energy metabolism by dietary polyphenols.

Blueberries Improve Pain, Gait Performance, and Inflammation in Individuals with Symptomatic Knee Osteoarthritis

Osteoarthritis (OA) is the most common joint disorder in the world and is the most frequent cause of walking related disability among older adults in the US, which brings a significant economic burden and reduces quality of life. The initiation and development of OA typically involves degeneration or progressive loss of the structure and function of articular cartilage. Inflammation is one of the major drives of the progression of OA. Dietary polyphenols have been studied for their anti-inflammatory properties and potential anabolic effects on the cartilage cells. Blueberries are widely consumed and are high in dietary polyphenols, therefore regular consumption of blueberries may help improve OA. The purpose of the present study was to examine the effect of freeze dried whole blueberries on pain, gait performance, and inflammation in individuals with symptomatic knee OA. In a randomized, double-blind trial, adults age 45 to 79 with symptomatic knee OA, were randomized to either consume 40 g freeze-dried blueberry powder (n = 33) or placebo powder (n = 30) daily for four months. Blood draws and assessment of pain and gait were conducted at baseline, two months, and four months. Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaires were used to assess pain and GAITRite^® electronic walkway was used to evaluate gait spatiotemporal parameters. WOMAC total score and sub-groups, including pain, stiffness, and difficulty to perform daily activities decreased significantly in the blueberry treatment group (p < 0.05), but improvement of WOMAC total score and difficulty to perform daily activities were not observed in the placebo group. Normal walking pace single support percentage for both limbs increased (p = or < 0.007), while double support percentage for both limbs decreased in the blueberry treatment group (p = or < 0.003). No significant changes were observed in plasma concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10, IL-13, matrix metalloproteinases (MMP)-3, MMP-13, and monocyte chemoattractant protein-1 (MCP-1) in both treatment groups. However, an increasing trend for IL-13 concentration and a decreasing trend in MCP-1 concentration were noted in the blueberry group. The findings of this study suggest that daily incorporation of whole blueberries may reduce pain, stiffness, and difficulty to perform daily activities, while improving gait performance, and would therefore improve quality of life in individuals with symptomatic knee OA.

Postprandial Effects of Blueberry (Vaccinium angustifolium) Consumption on Glucose Metabolism, Gastrointestinal Hormone Response, and Perceived Appetite in Healthy Adults: A Randomized, Placebo-Controlled Crossover Trial

The consumption of blueberries, as well as the phenolic compounds they contain, may alter metabolic processes related to type 2 diabetes. The study investigated the effects of adding 140 g of blueberries to a higher-carbohydrate breakfast meal on postprandial glucose metabolism, gastrointestinal hormone response, and perceived appetite. As part of a randomized crossover design study, 17 healthy adults consumed a standardized higher-carbohydrate breakfast along with 2 treatments: (1) 140 g (1 cup) of whole blueberries and (2) a placebo gel (matched for calories, sugars, and fiber of the whole blueberries). Each subject participated in two 2-h meal tests on separate visits ≥8 days apart. Venous blood samples and perceived appetite ratings using visual analog scales were obtained prior to and at 30, 60, 90, and 120 min after consuming the breakfast meals. Results show that glucose metabolism, several gastrointestinal hormones, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), peptide YY (PYY) concentrations and perceived appetite did not change significantly with blueberry consumption. However, pancreatic polypeptide (PP) concentrations were statistically significantly higher (p = 0.0367), and the concentrations were higher during 30, 60, 90, and 120 min after consumption of the blueberry breakfast meal than the placebo breakfast meal. Additional research is needed to determine whether blueberries and other flavonoid-rich foods reduce type 2 diabetes risk by modifying gastrointestinal hormones and perceived appetite.

Polyphenols regulating microRNAs and inflammation biomarkers in obesity

Obesity is one of the most prevalent health problems worldwide. It is a complex disease that is generally accompanied by insulin resistance, increases in oxidative stress and inflammation biomarkers, and potentially, microRNA (miRNA) dysregulation. Polyphenols may act on obesity and its metabolic consequences. Circulating miRNAs have been studied as potential biomarkers for inflammatory and metabolic diseases, and their use may improve the diagnostic tools currently available and the ability to diagnose specific diseases. To our knowledge, data regarding the link between the consumption of polyphenols from food sources, miRNA expression, and inflammation biomarkers related to obesity is scarce, and most data available describing this relationship are found in cancer studies. This review focuses on the polyphenols that modulate the metabolism, inflammation, or both related to obesity to understand the extent to which miRNA expression can be modulated by dietary interventions.

Effects of Two Doses of Curry Prepared with Mixed Spices on Postprandial Ghrelin and Subjective Appetite Responses-A Randomized Controlled Crossover Trial

Spices are known to provide orosensory stimulation that can potentially influence palatability, appetite, and energy balance. Previous studies with individual spices have shown divergent effects on appetite and energy intake measures. In a real-life context, however, several spices are consumed in combinations, as in various forms of curries. Therefore, we investigated changes in postprandial appetite and plasma ghrelin in response to the intake of two doses of curry prepared with mixed spices. The study was undertaken in healthy Chinese men, between 21 and 40 years of age and body mass index ≤27.5 kg/m². Appetite was measured using visual analogue scales (VAS) and plasma ghrelin was measured using multiplex assay. Compared with the control meal (Dose 0 Control (D0C), 0 g mixed spices), we found significantly greater suppression in 'hunger' (both p < 0.05, after Bonferroni adjustments) as well in 'desire to eat' (both p < 0.01) during the Dose 1 Curry (D1C, 6 g mixed spices) and Dose 2 Curry (D2C, 12 g mixed spices) intake. There were no differences, however, in plasma ghrelin or in other appetite measures such as in 'fullness' or in 'prospective eating' scores. Overall, the results of our study indicate greater inter-meal satiety due to mixed spices consumption, independent of any changes in plasma ghrelin response.

In vitro bioaccessibility and functional properties of polyphenols from pomegranate peels and pomegranate peels-enriched cookies

Obesity is an urgent social problem and new functional foods providing polyphenols and dietary fibers (DF) may be promising tools to modulate oxidative stress, inflammation and energy homeostasis. Pomegranate peels (PPe) are an agro-industrial by-product containing polyphenols such as ellagitannins (ETs), gallic acid (GA), ellagic acid (EA) and its derivatives (EAs), as well as DF. In this study, PPe enriched cookies (PPeC) were developed, and the bioaccessibility as well as the ability of their polyphenols to exert antioxidant activity along the Gastro-intestinal Tract (GiT) and to modulate digestive enzymes were evaluated in vitro. Data showed that the potential bioaccessibility of ETs was 40% lower from PPeC than PPe whereas EAs' and GA bioaccessibility increased by 93% and 52% for PPeC compared to PPe. The concentration of the polyphenols at each digestion step was associated with the total antioxidant capacity of the potentially bioaccessible material. Moreover the polyphenols released in the simulated duodenal phase upon PPeC digestion exhibited inhibitory activity towards α-glucosidase, α-amylase and lipase, being α-glucosidase > α-amylase > lipase. In conclusion, the data demonstrated that the inclusion of PPe at 7.5% in a bakery product potentially led to a high bioaccessibility of ETs' degradation products (mainly EA and EAs) in the duodenum, with a consequent antioxidant protection along the GiT and modulation of glucose metabolism. Further human studies are warranted to evaluate whether these effects also occur in vivo.

Effect of Incorporating Stevia and Moringa in Cookies on Postprandial Glycemia, Appetite, Palatability, and Gastrointestinal Well-Being

BACKGROUND

Medicinal plants including stevia and moringa constitute an important source of health-beneficial bioactive components, and hence their intake may beneficially modulate biomarkers of chronic diseases.

OBJECTIVE

The objective of the present study was to investigate the effect of incorporating stevia and moringa leaf powder in cookies on postprandial glycemia, appetite, palatability, and gastrointestinal well-being in humans.

METHOD

In a randomized crossover design, 20 healthy subjects consumed 3 isocaloric test foods (each providing 50 g available carbohydrates) of control cookies (CC) made from 100% wheat flour, cookies containing stevia leaf powder (SC, 3% w/w), and cookies containing moringa leaf powder (MC, 5% w/w) as breakfast. Blood glucose and subjective appetite were measured at fasting and at 15, 30, 45, 60, 90, and 120 min after the consumption of the cookies. Palatability and gastrointestinal well-being were measured using standard questionnaires.

RESULTS

Compared to CC, MC resulted in a significant decrease in postprandial blood glucose concentration at 30 and 45 min (p = 0.002 and p = 0.003, respectively) and showed a tendency (p = 0.077) for lower blood glucose incremental area under the curve (iAUC). Subjects were significantly less hungry after SC and MC intake (p = 0.035 and p = 0.041, respectively) compared to CC. All the cookies were liked by the subjects without any reported gastrointestinal discomfort.

CONCLUSION

The results showed that compared to CC, MC improved postprandial glycemia and reduced hunger, while SC reduced hunger only. Future studies are now warranted to explore the mechanisms responsible for these observed effects.

Biotransformation of quercetin by Gliocladium deliquescens NRRL 1086

With an attempt to synthesize high-value isoquercitrin (quercetin-3-O-β-D-glucopyranoside), we carried out the biotransformation of quercetin (1) by Gliocladium deliquescens NRRL 1086. Along with the aimed product quercetin 3-O-β-D-glycoside (2), three additional metabolites, 2-protocatechuoyl-phlorogucinol carboxylic acid (3), 2,4,6-trihydroxybenzoic acid (4), and protocatechuic acid (5), were also isolated. The time-course experiments revealed that there were two metabolic routes, regio-selectivity glycosylation and quercetin 2,3-dioxygenation, co-existing in the culture. Both glycosylation and oxidative cleavage rapidly took place after quercetin feeding; about 98% quercetin were consumed within the initial 8 h and the oxdized product (2-protocatechuoyl-phlorogucinol carboxylic acid) was hydrolyzed into two phenolic compounds (2,4,6-trihydroxybenzoic acid and protocatechuic acid). We also investigated the impact of glucose content and metal ions on the two reactions and found that high concentrations of glucose significantly inhibited the oxidative cleavage and improved the yield of isoquercitrin and that Ca²⁺, Fe²⁺, Mn²⁺, Mg²⁺, and Zn²⁺ inhibited glycosylation. To test the promiscuity of this culture, we selected other four flavonols as substrates; the results demonstrated its high regio-selectivity glycosylation ability towards flavonols at C-3 hydroxyl. In conclusion, our findings indicated that the versatile microbe of G. deliquescens NRRL 1086 maitained abundant enzymes, deserving further research.

Polyphenolic Phytochemicals in Cancer Prevention and Therapy: Bioavailability versus Bioefficacy

Natural polyphenols are organic chemicals which contain phenol units in their structures. They show antitumor properties. However, a key problem is their short half-life and low bioavailability under in vivo conditions. Still, definitively demonstrating the human benefits of isolated polyphenolic compounds (alone or in combination) using modern scientific methodology has proved challenging. The most common discrepancy between experimental and clinical observations is the use of nonphysiologically relevant concentrations of polyphenols in mechanistic studies. Thus, it remains highly controversial how applicable underlying mechanisms are with bioavailable concentrations and biological half-life. The present Perspective analyses proposed antitumor mechanisms, in vivo reported antitumor effects, and possible mechanisms that may explain discrepancies between bioavailability and bioefficacy. Polyphenol metabolism and possible toxic side effects are also considered. Our main conclusion emphasizes that these natural molecules (and their chemical derivatives) indeed can be very useful, not only as cancer chemopreventive agents but also in oncotherapy.

Contribution of anthocyanin-rich foods in obesity control through gut microbiota interactions

Obesity is characterized by low-grade inflammation and a number of metabolic disorders. Distal gut microbes' content (microbiota) is not yet fully understood but evidence shows that it is influenced by internal and external factors that modulate its composition and function. The evidence that gut microbiota composition can differ between healthy and obese individuals, as well as for those who maintain specific dietary habits, has led to the study of this environmental factor as a key link between the pathophysiology of obesity and gut microbiota. Data obtained about the role of anthocyanins (ACNs) in microbiota may lead to different strategies to manipulate bacterial populations and promote health. Anthocyanins have been identified as modulators of gut microbiota that contribute to obesity control and these bioactive compounds should be considered to have a prebiotic action. This review addresses the relevance of knowledge about the influence of anthocyanins-rich food consumption on microbiota, and their health-promoting potential in the pathophysiology of obesity. © 2017 BioFactors, 43(4):507-516, 2017.

Polyphenols and Their Role in Obesity Management: A Systematic Review of Randomized Clinical Trials

Polyphenols have been suggested to reduce body weight and modify body composition through different mechanisms. These effects have been extensively studied in animals and in vitro and to a lesser extent in humans. The aim of this review is to consider the association between polyphenols and body weight status by focusing on human intervention studies. We conducted a systematic literature search in MEDLINE (via EBSCOhost), ProQuest CENTRAL, and Cochrane CENTRAL without time restrictions. Randomized controlled trials assessing the effect of polyphenols on weight and/or body composition in the overweight and/or obese population were included. Nineteen studies met our inclusion criteria. Results suggest that further research is required before supporting a potential role of polyphenols in reducing weight in overweight and obese individuals (nine studies showed a significant decrease in weight by a mean of 1.47 ± 0.58 kg). Nevertheless, several studies indicated that polyphenols might be effective in preventing small increases in weight during periods of overfeeding rather than reducing weight as such. The outcomes noted do not yet support polyphenol supplementation as a complementary approach in weight loss diets. Further larger trials with a duration of 12 months or more are needed to elucidate the effect of polyphenols on body weight status. Copyright © 2017 John Wiley & Sons, Ltd.