Showing papers in "Food & Function in 2017"

A combination of quercetin and resveratrol reduces obesity in high-fat diet-fed rats by modulation of gut microbiota

Abstract: Resveratrol and quercetin, widely found in foods and vegetables, are plant polyphenols reported to have a wide range of biological activities. Despite their limited bioavailabilities, both resveratrol and quercetin are known to exhibit anti-inflammation and anti-obesity effects. We hypothesized that gut microbiota may be a potential target for resveratrol and quercetin to prevent the development of obesity. The aim of this research was to confirm whether a combination of quercetin and resveratrol (CQR) could restore the gut microbiota dysbiosis induced by a high-fat diet (HFD). In this study, Wistar rats were divided into three groups: a normal diet (ND) group, a HFD group and a CQR group. The CQR group was treated with a HFD and administered with a combination of quercetin [30 mg per kg body weight (BW) per day] and resveratrol [15 mg per kg body weight (BW) per day] by oral gavage. At the end of 10 weeks, CQR reduced the body weight gain and visceral (epididymal, perirenal) adipose tissue weight. Moreover, CQR also reduced serum lipids, attenuated serum inflammatory markers [interleukin (IL)-6, tumor necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1] and reversed serum biochemical parameters (adiponectin, insulin, leptin, etc.). Importantly, our results demonstrated that CQR could modulate the gut microbiota composition. 16S rRNA gene sequencing revealed that CQR had an impact on gut microbiota, decreasing Firmicutes (P < 0.05) and the proportion of Firmicutes to Bacteroidetes (P = 0.052). CQR also significantly inhibited the relative abundance of Desulfovibrionaceae (P < 0.01), Acidaminococcaceae (P < 0.05), Coriobacteriaceae (P < 0.05), Bilophila (P < 0.05), Lachnospiraceae (P < 0.05) and its genus Lachnoclostridium (P < 0.001), which were reported to be potentially related to diet-induced obesity. Moreover, compared with the HFD group, the relative abundance of Bacteroidales_S24-7_group (P < 0.01), Christensenellaceae (P < 0.001), Akkermansia (P < 0.01), Ruminococcaceae (P < 0.01) and its genera Ruminococcaceae_UCG-014 (P < 0.01), and Ruminococcaceae_UCG-005 (P < 0.01), which were reported to have an effect of relieving HFD-induced obesity, was markedly increased in the CQR group. Overall, these results indicated that administration of CQR may have beneficial effects on ameliorating HFD-induced obesity and reducing HFD-induced gut microbiota dysbiosis.

Differential α-amylase/α-glucosidase inhibitory activities of plant-derived phenolic compounds: a virtual screening perspective for the treatment of obesity and diabetes.

Abstract: Recently, due to their biological properties, polyphenol-rich functional foods have been proposed to be unique supplementary and nutraceutical treatments for diabetes mellitus. Inhibition of α-amylase and α-glucosidase enzymes using natural products (especially polyphenols) is a novel oral policy to regulate carbohydrate metabolism and hyperglycemia. The present study aims to evaluate the α-amylase and α-glucosidase inhibitory activity of 26 polyphenols using molecular docking and virtual screening studies. The results speculate that among selected compounds caffeic acid, curcumin, cyanidin, daidzein, epicatechin, eridyctiol, ferulic acid, hesperetin, narenginin, pinoresinol, quercetin, resveratrol and syringic acid can significantly inhibit the α-glucosidase enzyme. In addition, catechin, hesperetin, kaempferol, silibinin and pelargonidin are potent α-amylase inhibitors. Therefore the primary structure of polyphenols can change the inhibitory effect versus the α-amylase and α-glucosidase enzymes. Finally, we speculate that consumption of polyphenol-rich functional foods (by considering the best dose of each compound and assessing their possible side effects) in diabetic patients may be useful for regulating carbohydrate metabolism and related disorders. The findings of the current study may also shed light on a way of generating a new class of amylase/glucosidase inhibitors that will discriminately inhibit the on-target enzymes with negligible undesired off-target side effects.

Microalgae as healthy ingredients for functional food: a review

Abstract: Microalgae are very interesting and valuable natural sources of highly valuable bioactive compounds, such as vitamins, essential amino acids, polyunsaturated fatty acids, minerals, carotenoids, enzymes and fibre. Due to their potential, microalgae have become some of the most promising and innovative sources of new food and functional products. Moreover, microalgae can be used as functional ingredients to enhance the nutritional value of foods and, thus, to favourably affect human health by improving the well-being and quality of life, but also by curtailing disease and illness risks. This review provides an overview of the current knowledge of the health benefits associated with the consumption of microalgae, bioactive compounds, functional ingredients, and health foods.

A comprehensive review of the health perspectives of resveratrol

Abstract: Many natural products present in our diet, including flavonoids, can prevent the progression of cancer and other diseases. Resveratrol, a natural polyphenol present in various fruits and vegetables, plays an important role as a therapeutic and chemopreventive agent used in the treatment of various illnesses. It exhibits effects against different types of cancer through different pathways. It additionally exerts antidiabetic, anti-inflammatory, and anti-oxidant effects in a variety of cell types. Furthermore, the cardiovascular protective capacities of resveratrol are associated with multiple molecular targets and may lead to the development of novel therapeutic strategies for atherosclerosis, ischemia/reperfusion, metabolic syndrome, and heart failure. Accordingly, this article presents an overview of recent developments in the use of resveratrol for the prevention and treatment of different diseases along with various mechanisms. In addition, the present review summarizes the most recent literature pertaining to resveratrol as a chemotherapeutic agent against multiple diseases and provides an assessment of the potential of this natural compound as a complementary or alternative medicine.

Toxicity of cadmium and its health risks from leafy vegetable consumption.

Abstract: Cadmium (Cd) is a highly toxic heavy metal and has spread widely in the environment in recent decades. This review summarizes current knowledge about Cd contamination of leafy vegetables, its toxicity, exposure, health risks, and approaches to reducing its toxicity in humans. Leafy vegetable consumption has been identified as a dominant exposure pathway of Cd in the human body. An overview of Cd pollution in leafy vegetables as well as the main sources of Cd is given. Notable estimated daily intakes and health risks of Cd exposure through vegetable consumption for humans are revealed in occupational exposure areas and even in some reference areas. Vegetable consumption is one of the most significant sources of exposure to Cd, particularly in occupational exposure regions. Therefore, numerous approaches have been developed to minimize the accumulation of Cd in leafy vegetables, among which the breeding of Cd pollution-safe cultivars is one of the most effective tools. Furthermore, dietary supplements from leafy vegetables perform positive roles in alleviating Cd toxicity in humans with regard to the effects of essential mineral elements, vitamins and phytochemicals taken into the human body via leafy vegetable consumption.

Astaxanthin in cardiovascular health and disease: mechanisms of action, therapeutic merits, and knowledge gaps

Abstract: Cardiovascular disease is the main contributor to morbidity and mortality worldwide. Based on its unique chemical features, the xanthophyll carotenoid astaxanthin is being proposed as a suitable preventive and therapeutic agent in cardiovascular disease. This review focuses on recent advances in astaxanthin research relevant to cardiovascular health and disease, i.e. its direct antioxidant, indirect antioxidant, anti-inflammatory, anti-hypertensive, anti-diabetic, renoprotective, lipid-lowering and anti-atherosclerotic activities in vitro and in vivo. Disparities in the biological activities and health benefits of astaxanthin observed in vitro (strong evidence), in animals (moderate evidence), and in humans (weak evidence) and the variety of astaxanthin sources hamper efforts to establish areas of astaxanthin application in human health care. A list of knowledge gaps and experimental pitfalls is proposed to overcome some of the short-comings in astaxanthin research.

High internal phase emulsions stabilized solely by whey protein isolate-low methoxyl pectin complexes: effect of pH and polymer concentration.

Abstract: In recent years, there has been significant progress in edible emulsion technology especially with respect to creating and stabilizing surfactant-free emulsion systems for food applications. In this paper, we demonstrate the fabrication of high internal phase emulsions (HIPE) (φoil = 0.82) stabilized using colloidal complexes of non-gelling biopolymers (at concentrations as low as 0.3 wt%). The colloidal complexes were pre-formed by combining whey protein isolate (WPI) and low-methoxyl pectin (LMP) at three different pH values (i.e. pH 3.5, 4.5, 5.5) and used further for fabricating stable HIPEs. In addition to the effect of pH, the influence of total biopolymer concentration on the formation and properties of HIPEs was also evaluated. Depending on the total concentration of biopolymers used, the WPI–LMP complexes (formed at pH 4.5) showed a Z-average diameter in the range of 250–350 nm. It was found that the formation of HIPEs was strongly influenced by the pH of the colloidal complexes. At a pH close to the isoelectric point of WPI (≈pH 4.8) and WPI–LMP complexes (≈pH 3.4), severe aggregation of colloidal particles occurred, resulting in poor formation and stability of HIPEs. On comparing the stabilization behaviour of the complexes with the uncomplexed protein, it was noticed that the former provided comparatively better stabilization to the HIPEs against coalescence at pH 4.5 and 5.5. Based on the rheological data (low amplitude oscillatory shear rheology and flow measurements), all HIPE samples showed viscoelastic and shear-thinning behaviour. We believe that such viscoelastic gel-like systems could find potential commercial applications in the development of label-friendly novel food products with interesting textures.

Gastrointestinal interactions, absorption, splanchnic metabolism and pharmacokinetics of orally ingested phenolic compounds

Abstract: The positive health effects of phenolic compounds (PCs) have been extensively reported in the literature. An understanding of their bioaccessibility and bioavailability is essential for the elucidation of their health benefits. Before reaching circulation and exerting bioactions in target tissues, numerous interactions take place before and during digestion with either the plant or host's macromolecules that directly impact the organism and modulate their own bioaccessibility and bioavailability. The present work is focused on the gastrointestinal (GI) interactions that are relevant to the absorption and metabolism of PCs and how these interactions impact their pharmacokinetic profiles. Non-digestible cell wall components (fiber) interact intimately with PCs and delay their absorption in the small intestine, instead carrying them to the large intestine. PCs not bound to fiber interact with digestible nutrients in the bolus where they interfere with the digestion and absorption of proteins, carbohydrates, lipids, cholesterol, bile salts and micronutrients through the inhibition of digestive enzymes and enterocyte transporters and the disruption of micelle formation. PCs internalized by enterocytes may reach circulation (through transcellular or paracellular transport), be effluxed back into the lumen (P-glycoprotein, P-gp) or be metabolized by phase I and phase II enzymes. Some PCs can inhibit P-gp or phase I/II enzymes, which can potentially lead to drug–nutrient interactions. The absorption and pharmacokinetic parameters are modified by all of the interactions within the digestive tract and by the presence of other PCs. Undesirable interactions have promoted the development of nanotechnological approaches to promote the bioaccessibility, bioavailability, and bioefficacy of PCs.

Exosomal delivery of berry anthocyanidins for the management of ovarian cancer

Abstract: Despite optimal diagnosis and early therapeutic interventions, the prognosis for ovarian cancer patients remains dismal because the efficacy of chemotherapy is limited by the development of resistance and off-site toxicity. Berry bioactives indicate preventive and therapeutic activities against various cancer types. Here, we examined the antiproliferative activity of berry anthocyanidins (Anthos) against drug-sensitive (A2780) and drug-resistant (A2780/CP70, OVCA432 and OVCA433) ovarian cancer cells. These drug-resistant ovarian cancer cell lines overexpress p-glycoproteins (PgP) and show >100-fold resistance to the chemotherapeutic drug cisplatin compared to A2780. We observed a dose-dependent growth inhibition of ovarian cancer cells with the Anthos. Furthermore, the treatment of drug-resistant ovarian cancer (OVCA433) cells with cisplatin in combination with the Anthos (75 μM) resulted in significantly higher cell killing. The cisplatin dose required to achieve this effect was 10 to 15-fold lower than the IC50 of cisplatin alone. However, many plant bioactives including Anthos face the challenge of poor oral bioavailability and stability. Recently, we have developed strategies to overcome these limitations by delivering Anthos via milk-derived exosomes. The exosomal Anthos (ExoAnthos) significantly enhanced the antiproliferative activity against the growth of ovarian cancer cells and inhibited tumor growth more efficiently compared to Anthos alone and a vehicle control. Often patients with cisplatin-resistant tumors retain sensitivity to paclitaxel (PAC). We prepared exosomal formulations of PAC (ExoPAC) for oral delivery as the systemic administration of PAC has severe side effects. ExoPAC delivered orally showed the same therapeutic efficacy as the free PAC delivered intraperitoneally. Finally, we report that the combination of the Anthos and PAC decreased the PgP level in a dose-dependent manner in OVCA432 cells. A significantly enhanced antitumor activity was observed with the combination of ExoPAC and ExoAnthos against A2780 tumor xenografts. Together, our data indicate that the berry Anthos are highly effective against ovarian cancer and that the milk exosomes serve as an excellent nano-carrier to enhance the drug's oral bioavailability for the management of ovarian cancer.

Ethylcellulose oleogels for lipophilic bioactive delivery – effect of oleogelation on in vitro bioaccessibility and stability of beta-carotene

Abstract: The in vitro lipolysis and β-carotene (BC) transfer from oil to aqueous phase of canola oil ethylcellulose (EC) oleogels were measured using a static monocompartmental model simulating oral, gastric, and duodenal digestive stages. The effects of EC oleogelation on gel in vitro digestibility were examined, using un-structured canola oil as a control. The physicochemical properties of oleogels containing BC were also measured. It was found that oleogels made with 10% 10 cP and 10% 20 cP did not differ significantly in their extent of lipolysis or BC transfer compared to canola oil; however 10% 45 cP and 15.5% 20 cP had a significantly lower extent of lipolysis and BC transfer compared to other formulations. The structure and mechanical strength of the oleogels were both determined to be factors affecting lipolysis and transfer. The presence of BC did not significantly affect the mechanical strength of the gels and EC oleogelation delayed BC degradation under accelerated storage conditions compared to a heated canola oil control. These findings could contribute to the development of new applications for EC oleogels, specifically for the effective delivery of lipophilic molecules.

Effects of different oligosaccharides at various dosages on the composition of gut microbiota and short-chain fatty acids in mice with constipation

Abstract: The aim of this study was to evaluate the effects of three different kinds of oligosaccharides (a fructo-oligosaccharide (FOS) formulation consisting of 95% FOS (FOS95); a galacto-oligosaccharide (GOS) formulation consisting of 90% GOS (GOS90) and an isomalto-oligosaccharide (IMO) formulation consisting of 90% IMO (IMO90)) at dosages of 0.8, 4 g per d per kg bw and 8 g per d per kg bw on the composition and activity of the microbiota in the gut of mice with constipation induced by loperamide. Oligosaccharides were intragastrically administered to specific pathogen-free BALB/c mice once per day for 17 days. Feces were collected during a feeding trial and subjected to 16S rDNA amplicon analysis. Constipation indices, changes in gut microbiota and metabolic activity were measured to evaluate the effects of the oligosaccharides. The results show that oligosaccharides treated constipation by increasing both the water content of the feces and the small intestinal transit rate. The dosage required to treat constipation was different for different oligosaccharides. High-dose GOS90 was the most effective in relieving constipation, followed by medium-dose FOS95 and IMO90. The fecal samples were investigated after the oligosaccharide treatment. All three oligosaccharides increased the ratio of acetic acid and decreased the ratio of propionic and butyric acids in the feces. The increase in the ratio of acetic acid and the concentration of butyric acid were found to have relatively larger effects on constipation. After treatment with oligosaccharides, the gut microbiotas of the mice were dominated by Firmicutes, Bacteroidetes and Actinobacteria. At the genus level, oligosaccharide treatment increased the levels of Lactobacillus and Bifidobacterium and decreased the levels of Odoribacter, Alistipes and Bacteroides. In conclusion, our results demonstrate that oligosaccharides administered as a dietary supplement increase the water content of feces, reduce intestinal transit time, modulate the composition of the gut microbiota and increase the concentration of short-chain fatty acids in the feces of mice with constipation.

Food and Plant Bioactives for Reducing Cardiometabolic Disease Risk: An Evidence Based Approach

Abstract: Cardiovascular diseases (CVDs) are one of the major causes of mortality and disability in Western countries. Prevention is known to be the cornerstone to lessen the incidence of CVDs and also to reduce the economic burden of both the citizen and the healthcare system. “Interventional medicine” certainly puts lifestyle modification as the first therapeutic step, including a healthy diet and physical activity. Secondly, a large body of research individuated a number of food and plant bioactives, which are potentially efficacious in preventing and reducing some highly prevalent CV risk factors, such as hypercholesterolemia, hypertension, vascular inflammation and vascular compliance. Some lipid- and blood pressure-lowering bioactives were studied for their impact on human vascular health, particularly as regards endothelial function and arterial stiffness. Several nutraceuticals showed additive or synergistic properties in combination, sometimes (but not always) allowing a reduction of the administered dose of extracts and determining a “multi-factorial” final effect on many cardiovascular risk factors. Thus, this review focuses on available evidence regarding the effects of berberine, plant sterols, green tea extract, soy, curcumin, cocoa, pycnogenol, lycopene, olive oil, soluble fibers, garlic, resveratrol, beetroot, mineral salts and vitamins on the lipid profile, blood pressure, inflammatory and endothelial markers, and vascular compliance. Future clinical research studies will have to focus more on middle term modification of the instrumental markers of vascular aging than on short-term effects on indirect laboratory risk markers.

Lactobacillus casei CCFM419 attenuates type 2 diabetes via a gut microbiota dependent mechanism

Abstract: Probiotics, as dietary supplements, transmit their major effects through the regulation of gut microbiota. According to a previous study, one possible mechanism of Lactobacillus casei CCFM419 protection against diabetes may involve gut flora. To test this hypothesis, high fat and streptozotocin-induced C57BL/6J mice were fed L. casei CCFM419 at 108, 109, and 1010 colony forming units (CFU). Compared to untreated mice, 109 CFU of L. casei CCFM419 attenuated several symptoms of diabetes, including fasting blood glucose, postprandial blood glucose, glucose intolerance, and insulin resistance. In addition, this CFU level also decreased the levels of the inflammatory markers tumor necrosis factor-α and interleukin-6 and increased intestinal glucagon-like peptide-1 (GLP-1) levels, which are associated with the production of short chain fatty acids (SCFAs). The 16S rRNA gene sequencing of fecal samples demonstrated that 109 CFU of L. casei CCFM419 dramatically increased the abundance of Bacteroidetes and decreased the proportion of Firmicutes at the phylum level, and enriched Bifidobacterium, Lactobacillus, and SCFA-producing bacteria, including Allobaculum and Bacteroides. These findings suggested that L. casei CCFM419 modified the gut flora-SCFA-inflammation/GLP-1 mechanism to ameliorate type 2 diabetes.

Dietary fucoidan of Acaudina molpadioides alters gut microbiota and mitigates intestinal mucosal injury induced by cyclophosphamide

Abstract: Cyclophosphamide (cy) is a widely used cancer drug. Many researchers have focused on the prevention and alleviation of its side effects, particularly damage to the intestinal mucosal barrier. In this study, we examined the effects of fucoidan, isolated from Acaudina molpadioides, on mice with intestinal mucosal damage induced by cyclophosphamide. Our results showed that fucoidan intervention could relieve injury such as decreasing inflammation and increasing the expression of tight junction proteins, and 50 kDa fucoidan significantly increased the abundance of short chain fatty acid (SCFA) producer Coprococcus, Rikenella, and Butyricicoccus (p < 0.05, p < 0.001, and p < 0.05, respectively) species within the intestinal mucosa compared with the cyclophosphamide group, as determined by 16S rDNA gene high-throughput sequencing. In addition, SCFAs, particularly propionate, butyrate, and total SCFAs, were increased in the feces, and SCFA receptors were upregulated in the small intestine. The protective effects of fucoidan on cyclophosphamide treatment may be associated with gut microflora, and 50 kDa fucoidan had superior effects. Therefore, fucoidan may have applications as an effective supplement to protect against intestinal mucosal barrier damage during chemotherapy.

Digestibility and supramolecular structural changes of maize starch by non-covalent interactions with gallic acid

Abstract: The effects of non-covalent interactions between gallic acid (GA) and starch on starch digestibility and supramolecular structural changes (short-range ordered molecular structure, crystalline structure, lamellar structure and fractal structure) were investigated. The results indicated that the digestibility of both starches was substantially reduced in the rapidly digestible starch (RDS) content, but resistant starch (RS) was increased after interacting with GA. The RS content of starch–GA complexes ranged from 17.70 to 50.02%, which is much higher than that of high amylose starch (G50) (11.11%) and normal maize starch (NMS) (4.46%). Compared with native starches, starch–GA complexes possess more ordered and compact structures; furthermore, G50–GA complexes possessed more compact scattering objects, thicker crystalline lamellae and thinner amorphous lamellae than those of NMS–GA complexes. This revealed that more ordered multi-scale structures promote the RS formation. Docking studies were conducted to reveal the mechanism of digestibility variations. It showed that GA would non-covalently interact with starch molecules and contribute to ordered structure formation to somewhat extent; meanwhile, GA had higher binding affinities to α-amylase than to starch chains; during the hydrolytic process, GA could be released from the complex and was more likely to occupy the active sites of Asp197, Asp300, His299 and Glu233 by hydrogen bonds and van der Waals forces, which kept starch out of the active site pocket and reduced starch digestibility. These results demonstrate that the non-covalent interactions between GA and starch could be a promising method of controlling starch structures and starch digestion behaviors.

Relating rheology and tribology of commercial dairy colloids to sensory perception

Abstract: This study aims to investigate the relationship between rheological and tribological properties of commercial full fat and fat-free/low fat versions of liquid and soft solid colloidal systems (milk, yoghurt, soft cream cheese) with their sensory properties. Oscillatory measurements (strain, frequency), flow curves and tribological measurements (lubrication behaviour using Stribeck analysis) were conducted. Oral condition was mimicked using artificial saliva at 37 ○C. Discrimination test was conducted by 63 untrained consumers, followed by a qualitative questionnaire. Consumers significantly discriminated the fat-free/low fat from the full fat versions (p 0.05). Full fat and fat free yoghurts had similar yielding behaviour and elastic modulus (G′), even in simulated oral conditions. However, in case of soft cream cheese, the full fat version had a moderately higher G′ than the low fat counterpart. Even in presence of artificial saliva, there was slight but significant difference in viscoelasticity between the cream cheese variants depending on fat content (p 0.05). Results suggest that sensory distinction between fat-free and full fat versions, particularly in semi-solid systems could be better predicted by lubrication data as compared to bulk rheology.

A comparison study on polysaccharides extracted from Laminaria japonica using different methods: structural characterization and bile acid-binding capacity

Abstract: In this study, the structural characterization and bile acid-binding capacity of Laminaria japonica polysaccharides (LP), obtained by seven different extraction methods, were investigated. The results indicated that extraction methods exhibited significant effects on extraction yield, molecular weight, monosaccharide composition and the content of neutral sugar, fucose, uronic acid and sulfate of LP. AFM analysis indicated that LP extracted by different methods exhibited certain different, flexible and worm-like chains with many branches. Rheological measurements showed that the LP, obtained by pressurized hot water extraction and acid assisted extraction, exhibited lower viscosity due to their lower molecular weight, compared to other extracted polysaccharides. The bile acid-binding capacity of acid assisted extracted LP was significantly higher than other LP samples tested, which was probably ascribed to its highly branched structure, low molecular weight, low viscosity and abundant uronic acid and fucose in total monosaccharides. The present study provides scientific evidence and advances in the preparation technology and a method for evaluating hypolipidemic activities of L. japonica polysaccharides.

Bioaccessibility and bioavailability of phenolic compounds in bread: a review

Abstract: Cereal-based products, like breads, are a vehicle for bioactive compounds, including polyphenols. The health effects of polyphenols like phenolic acids (PAs) are dependent on their bioaccessibility and bioavailability. The present review summarizes the current understanding of potential strategies to improve phenolic bioaccessibility and bioavailability and the main findings of in vitro and in vivo studies investigating these strategies applied to breads, including the use of raw ingredients with greater phenolic content and different pre-processing technologies, such as fermentation and enzymatic treatment of ingredients. There is considerable variability between in vitro studies, mainly resulting from the use of different methodologies, highlighting the need for standardization. Of the few in vivo bioavailability studies identified, acute, single-dose studies demonstrate that modifications to selected raw materials and bioprocessing of bran could increase the bioavailability, but not necessarily the net content, of bread phenolics. The two medium-term identified dietary interventions also demonstrated greater phenolic content, resulting from the modification of the raw materials used. Overall, the findings suggest that several strategies can be used to develop new bread products with greater phenolic bioaccessibility and bioavailability. However, due to the large variability and the few studies available, further investigations are required to determine better the usefulness of these innovative processes.

Digestion of isolated legume cells in a stomach-duodenum model: three mechanisms limit starch and protein hydrolysis.

Abstract: Retention of intact plant cells to the end of the small intestine leads to transport of entrapped macronutrients such as starch and protein for colonic microbial fermentation, and is a promising mechanism to increase the content of resistant starch in diets. However, the effect of gastro-intestinal bio-mechanical processing on the intactness of plant cells and the subsequent resistance to enzymatic digestion of intracellular starch and protein are not well understood. In this study, intact cells isolated from legume cotyledons are digested in a laboratory model which mimics the mechanical and biochemical conditions of the rat stomach and duodenum. The resulting digesta are characterised in terms of cell (wall) integrity as well as intracellular starch and protein hydrolysis. The cells remained essentially intact in the model with negligible (ca. 2–3%) starch or protein digestion; however when the cells were mechanically broken and digested in the model, the hydrolysis was increased to 45–50% suggesting that intact cellular structures could survive the mixing regimes in the model stomach and duodenum sufficiently to prevent digestive enzyme access. Apart from intact cell walls providing effective barrier properties, they also limit digestibility by restricting starch gelatinisation during cooking, and significant non-specific binding of α-amylase is observed to both intact and broken cell wall components, providing a third mechanism hindering starch hydrolysis. The study suggests that the preservation of intactness of plant cells, such as from legumes, could be a viable approach to achieve the targeted delivery of resistant starch to the colon.

Healthy properties of green and white teas: an update.

Abstract: Green tea has been consumed for centuries in Japan, China and Morocco. White tea, which is considered a variety of green tea, is mostly consumed in China and is very appreciated for its flavor. Currently the consumption of both types of tea has been extended to the western countries even as a functional ingredient. A group of polyphenols called catechins stands out among their bioactive components, the most abundant being the (−) epigallocatechin gallate, with high antioxidant power. Teas also contain other phenolic compounds such as gallic, caffeic, chlorogenic or cinnamic acids, quercetin and proanthocyanidols, caffeine, theophylline, L-theanine and minerals such as fluorine, manganese or chromium. Investigations have mainly been focused on their antioxidant potential and their implication in the prevention and treatment of degenerative diseases. Several studies have evaluated their role in cardiovascular diseases, body weight control, bone mass increase, protection against neurodegenerative diseases and improvement of type 2 diabetes, among other pathologies. The main points of controversy are the design and interpretation of epidemiological and human intervention studies and the lack of information on catechins availability, metabolism and biotransformation. This review compiles and analyzes the latest peer-reviewed papers published from 2002 up to February 2017, including systematic reviews and meta-analyses.

Molecular adaptations underlying the beneficial effects of hydroxytyrosol in the pathogenic alterations induced by a high-fat diet in mouse liver: PPAR-α and Nrf2 activation, and NF-κB down-regulation

Abstract: Scope: Non-alcoholic fatty liver disease (NAFLD) is a condition characterized by an increment in the liver fat content, with a concomitant reduction in the content of n-3-long chain polyunsaturated fatty acids (n-3 LCPUFAs), downregulation of PPAR-α activity, and upregulation of NF-κB activity, effects that induce pro-lipogenic and pro-inflammatory responses. Hydroxytyrosol (HT), a polyphenol with cytoprotective effects present in extra virgin olive oil, improves the cellular antioxidant capacity for activation of transcription factor Nrf2. The objective of this work is to evaluate the molecular adaptations involved in the anti-lipogenic, anti-inflammatory, and anti-oxidant effects of HT supplementation in high-fat diet (HFD)-fed mice. Methods and results: Male C57BL/6J mice received (i) control diet (10% fat); (ii) control diet + HT (daily doses of 5 mg per kg body weight), (iii) HFD (60% fat); or (iv) HFD + HT for 12 weeks. HFD-fed mice exhibited (i) liver steatosis; (ii) inflammation; (iii) oxidative stress; and (iv) depletion of n-3 LCPUFAs, together with down-regulation of PPAR-α and Nrf2, and up-regulation of NF-κB. HT supplementation attenuated the metabolic alterations produced by HFD, normalizing the activity of Nrf2, reducing the drop in activity of PPAR-α, and attenuating increment of NF-κB activation. Conclusion: Supplementation with HT activating transcription factors PPAR-α and Nrf2, along with the deactivation of NF-κB, may reduce the liver alterations induced in HFD-fed mice.

Encapsulation of flavonoids in liposomal delivery systems: the case of quercetin, kaempferol and luteolin.

Abstract: The instability of dietary flavonoids is currently a challenge for their incorporation in functional foods. This study investigated the protective effects of liposome encapsulation on a variety of flavonoids and their interaction mechanisms. It was found that the incorporation of flavonoids into the liposomal membrane was strongly dependent on their structure and loading concentration. Liposomes loading quercetin and luteolin exhibited a relatively small size and homogeneous suspension compared to those loading kaempferol. Additionally, liposomes displayed a stronger retaining ability to quercetin and luteolin than kaempferol during preparation, storage, heating and pH shock. After encapsulation, quercetin displayed the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and lipid peroxidation inhibition capacity, followed by kaempferol and luteolin. Raman and IR spectroscopy techniques demonstrated that flavonoids could modulate the dynamic and packing order of lipid chains, which were responsible for the stabilization of liposomes. Our findings should guide the rational design of liposomal encapsulation technology to efficiently deliver flavonoids in nutraceuticals and functional foods.

Development of stable Pickering emulsions/oil powders and Pickering HIPEs stabilized by gliadin/chitosan complex particles

Abstract: In this paper, we demonstrate the use of gliadin/chitosan complex particles (GCCPs) as particulate stabilizers of oil-in-water emulsions of natural oils and water. For this purpose, we fabricated GCCPs through a facile anti-solvent procedure and demonstrated their usage in the formation of Pickering emulsions and Pickering high internal phase emulsions (HIPEs). The GCCPs can be used to produce surfactant-free o/w Pickering emulsions and Pickering HIPEs; unfortunately these emulsions were labile to coalescence. NaCl addition and/or pH regulation, and the combination were used to modify the surface wettability of the complex particles to achieve stable emulsions. The microstructures, e.g., interfacial frameworks, GCCP partition between the continuous phase and interfacial region, and the state of the droplets, of Pickering emulsions were visualized by confocal laser scanning microscopy (CLSM), confirming that the inclusion of NaCl and slightly adjusting pH toward 4.0 and/or 5.0 benefited the adsorption and accumulation of colloid particles at the droplet surface to form an engineered interfacial structure, bridging droplets together through a percolating layer of colloidal particles at the oil/water interface. A schematic representation for the formation route of the emulsions is proposed to relate the physical performance and rheological property with the interfacial structures and aggregate behaviors in the Pickering system stabilized by the complex particles. Interestingly, direct freeze-drying of the emulsions transformed unstable Pickering emulsions into stable oil powders. This study opens a promising route based on Pickering HIPEs or oil powders to structure liquid oils into solid-like fats without artificial trans-fat, which outlines new directions for future fundamental research.

Dietary fibre-based SCFA mixtures promote both protection and repair of intestinal epithelial barrier function in a Caco-2 cell model.

Abstract: Impaired gut barrier function plays an important role in the development of many diseases such as obesity, inflammatory bowel disease, and in HIV infection. Dietary fibres have been shown to improve intestinal barrier function through their fermentation products, short chain fatty acids (SCFAs), and the effects of individual SCFAs have been studied. Here, different SCFA mixtures representing possible compositions from fibre fermentation products were studied for protective and reparative effects on intestinal barrier function. The effect of fermentation products from four dietary fibres, i.e. resistant starch, fructooligosaccharides, and sorghum and corn arabinoxylan (varying in their branched structure) on barrier function was positively correlated with their SCFA concentration. Pure SCFA mixtures of various concentrations and compositions were tested using a Caco-2 cell model. SCFAs at a moderate concentration (40–80 mM) improved barrier function without causing damage to the monolayer. In a 40 mM SCFA mixture, the butyrate proportion at 20% and 50% showed both a protective and a reparative effect on the monolayer to disrupting agents (LPS/TNF-α) applied simultaneously or prior to the SCFA mixtures. Relating this result to dietary fibre selection, slow fermenting fibres that deliver appropriate concentrations of SCFAs to the epithelium with a high proportion of butyrate may improve barrier function.

In vivo fermentation of a Pleurotus eryngii polysaccharide and its effects on fecal microbiota composition and immune response

Abstract: A novel, homogeneous Pleurotus eryngii polysaccharide (PEP) (molecular weight 426 kDa, purity 91.25 ± 3.14%) which mainly consisted of glucose with β-type glycosidic linkages was used to investigate in vivo fermentation behavior and effects on immune response in mice. Different doses (0.2, 0.4, 0.8 g per kg body weight) were orally administered to the mice for a period of six weeks. The results showed that the SCFA concentration, pH value, and moisture contents of cecum and colon contents were significantly altered with high-dose PEP treatment compared to the control group (P < 0.05). Moreover, the fecal microbiota in the PEP treated group was found to be structurally different compared to the control group; especially, the Porphyromonadaceae, Rikenellaceae, Bacteroidaceae and Lactobacillaceae abundances were all increased at the family level. In addition, the exerted immune response was significantly altered after the high-dose PEP oral administration. This exploratory study indicated that intake of PEP could have a positive role in gastrointestinal tract health.

Polydatin attenuates potassium oxonate-induced hyperuricemia and kidney inflammation by inhibiting NF-κB/NLRP3 inflammasome activation via the AMPK/SIRT1 pathway

Abstract: This study was designed to investigate the effects of polydatin (PLD) on potassium oxonate-induced hyperuricemic rats. Hyperuricemic rats were treated with potassium oxonate (250 mg kg−1) intragastrically for 7 days, and polydatin (25, 50 mg kg−1) or allopurinol (5 mg kg−1) was administered to the rats 1 h after the potassium oxonate exposure. Polydatin administration decreased the levels of uric acid and creatinine in serum and urine, leading to inhibition of pro-inflammatory cytokine production in serum and kidney. Western blot analyses illustrated that polydatin down-regulated the translocation of NF-κB p65, the degradation of IκBα, and the protein levels of inflammasome components (NLRP3, ASC, and caspase-1), which led to reduced IL-1β secretion. Notably, polydatin treatment activated AMP kinase (AMPK) protein and increased SIRT1 expression. Taken together, polydatin might be a promising agent for gouty treatment to inhibit renal NF-κB/NLRP3 inflammasome activation via the AMPK/SIRT1 pathway.

Current knowledge of intestinal absorption of bioactive peptides

Abstract: Peptides have been demonstrated as potentially beneficial compounds against several life-style related diseases such as hypertension, hypercholesterolemia, and atherosclerosis, among others. However, limited research has been carried out on peptide absorption, resulting in a lack of understanding and control of this process. Therefore, this review discusses the recent insights gathered on in vitro and in vivo absorption of peptides across intestinal membranes, into blood circulation. Briefly, some di-/tripeptides permeate through intestinal membranes in their intact forms via peptide transporter systems, while others are vulnerable to protease degradation. Oligopeptides (>tetrapeptides) show a lower transport ability than di-/tripeptides, possibly due to the presence of paracellular tight junctions. The hydrophobicity of peptides (log P) does not seem to influence absorption, while peptide length and degradation of peptides (and peptide sequences) by intestinal proteases may be determinant factors of the absorption process.

Rice bran constituents: immunomodulatory and therapeutic activities.

Abstract: Rice bran, one of the most abundant and valuable byproducts produced during the rice milling process, is of steadily growing interest in recent years due to its potential health benefits. Evidence is rapidly accumulating for the beneficial effects of nutraceuticals. However, the potential benefits of rice bran are found in several of its bioactive ingredients including oils, polysaccharides, proteins, and micronutrients. In addition, a significant advantage of rice bran is that it contains more than 100 antioxidants and several categories of bioactive phytonutrients, such as polyphenols, phytosterols, tocotrienols, γ-oryzanol, B vitamins, minerals, and trace minerals. As an immunomodulator, rice bran has beneficial constituents such as polysaccharides, proteins, and oils. Numerous studies also reported that potent antioxidants in rice bran included immune system enhancing compounds, such as phytosterols, polysaccharides, minerals and trace minerals including magnesium, selenium, zinc, vitamin E, omega-3 fatty acids and several other phytonutrients. We believe that this review will be a valuable resource for more studies on rice barn as a dietary source.

Beneficial effects of Lycium barbarum polysaccharide on spermatogenesis by improving antioxidant activity and inhibiting apoptosis in streptozotocin-induced diabetic male mice

Abstract: Spermatogenic dysfunction is one of the major secondary complications of diabetes. L. barbarum polysaccharide (LBP) has long been considered to possess anti-apoptotic activities and antioxidant, anti-inflammatory and fertility-enhancing properties in traditional medical practices in China. The aim of the current study was to seek out scientific evidence to determine if LBP also contributes to the recovery from spermatogenic dysfunction in diabetic individuals. We investigated whether the oral administration of LBP in streptozotocin (STZ)-induced type-1 diabetic male mice would reverse spermatogenic dysfunction and improve histological damage in testes. After the oral administration of LBP (10, 20 or 40 mg kg−1, respectively), sildenafil citrate (5 mg kg−1) or saline for 62 consecutive days, the sperm parameters were analyzed. Macroscopic and microscopic changes in the reproductive organs, including their weight, and photomicroscope and electronmicroscope images were also assessed. In addition, the antioxidant capacity and levels of malondialdehyde in the testes were determined according to the instructions provided with the assay kits and the expression of the apoptosis-related proteins, Caspase-3, Bax and Bcl-2, in the testes was analyzed using western-blot analysis. LBP treatment of diabetic mice considerably recovered the sperm parameters, increased the weight of the reproductive organs, ameliorated their histological appearance and increased antioxidant enzyme activity to different degrees. Moreover, our data also showed a marked decrease in Caspase-3 expression and an increase in the ratio of Bcl-2/Bax 43 after LBP administration (40 mg kg−1) when compared to the diabetic group. These results demonstrate that LBP exerts protective effects on diabetes induced male spermatogenic dysfunction, which is likely to be mediated through increasing antioxidant enzyme activities and inhibiting cell death.

Anti-hyperlipidemic effect of rice bran polysaccharide and its potential mechanism in high-fat diet mice.

Abstract: Hyperlipidemia occurs very often in modern society along with a high calorie intake and is regarded as one of the greatest risk factors for the prevalence of cardiac vascular disease (CVD). In this study, we investigated the anti-hyperlipidemic effect of the rice bran polysaccharides (RBP) and its mechanism in a high fat diet animal model. 60 ICR mice were randomly divided into 3 groups, which included Control, HFD (high fat diet) and HFD + RBP, and each group included 20 mice. The control group was fed with a standard diet while the other two groups were fed with HFD. In addition, the HFD + RBP group was fed with 500 mg kg-1 of rice bran polysaccharides by intragastric administration while the other two groups were intragastrically administered with water. The results showed that RBP treatment for 10 weeks obviously decreased the body weight, liver weight and adipose tissues of mice; and it decreased the levels of total cholesterol (TC), triglycerides (TG) and low density lipoprotein-cholesterol (LDL-c) in the plasma. H&E staining of the liver tissues showed that RBP treatment decreased the size of fat droplets compared with the HFD group. Microarray analysis revealed that RBP treatment results in 80 genes being up-regulated while 72 genes were down-regulated in the tissues of liver. IPA software analysis suggested that NF-κB may play a vital role in the lipid-lowering effect of RBP. Real-time quantitative PCR confirmed that the mRNA levels of PPAR-α, PPAR-γ, PPAR-δ, SREBP-1C, FASN, ACC, SIRT and CD36, which are related to lipid metabolism, were significantly regulated by RBP supplementation compared to HFD. The western blot analysis further confirmed these altered expressions after RBP treatment. Taken together, these results suggest that the oral administration of RBP exerts lipid-lowering in high fat diet mice via regulating the lipid metabolism-related gene expression.