Effect of punicalagin on multiple targets in streptozotocin/high-fat diet-induced diabetic mice

Punicalagin attenuates hyperuricemia via restoring hyperuricemia-induced renal and intestinal dysfunctions

INTRODUCTION

It is estimated that 90% of hyperuricemia cases are attributed to the inability to excrete uric acid (UA). The two main organs in charge of excreting UA are the kidney (70%) and intestine (30%). Previous studies have reported that punicalagin (PU) could protect against kidney and intestinal damages, which makes it a potential candidate for alleviating hyperuricemia. However, the effects and deeper action mechanisms of PU for managing hyperuricemia are still unknown.

OBJECTIVE

To investigate the effect and action mechanisms of PU for ameliorating hyperuricemia.

METHODS

The effects and action mechanisms of PU on hyperuricemia were assessed using a hyperuricemia mice model. Phenotypic parameters, metabolomics analysis, and 16S rRNA sequencing were applied to explore the effect and fundamental action mechanisms inside the kidney and intestine of PU for improving hyperuricemia.

RESULTS

PU administration significantly decreased elevated serum uric acid (SUA) levels in hyperuricemia mice, and effectively alleviated the kidney and intestinal damage caused by hyperuricemia. In the kidney, PU down-regulated the expression of UA resorption protein URAT1 and GLUT9, while up-regulating the expression of UA excretion protein ABCG2 and OAT1 as mediated via the activation of MAKP/NF-κB in hyperuricemia mice. Additionally, PU attenuated renal glycometabolism disorder, which contributed to improving kidney dysfunction and inflammation. Similarly, PU increased UA excretion protein expression via inhibiting MAKP/NF-κB activation in the intestine of hyperuricemia mice. Furthermore, PU restored gut microbiota dysbiosis in hyperuricemia mice.

CONCLUSION

This research revealed the ameliorating impacts of PU on hyperuricemia by restoring kidney and intestine damage in hyperuricemia mice, and to be considered for the development of nutraceuticals used as UA-lowering agent.

Inhibition of Hyperglycemia and Hyperlipidemia by Blocking Toll-like Receptor 4: Comparison of Wild-Type and Toll-like Receptor 4 Gene Knockout Mice on Obesity and Diabetes Modeling

Innate immune receptor TLR4 plays an important role in glycolipid metabolism. The objective of this study is to investigate the inhibitory effects of blocking TLR4 on hyperglycemia and hyperlipidemia by comparing WT and TLR4-/- mice in obesity and diabetes modeling. The knockout of the TLR4 gene could prevent weight gain induced by a high-fat diet (HFD)/high-sugar and high-fat diet (HSHFD), and the differences in the responses existed between the sexes. It extends the time required to reach the obesity criteria. However, when mice were injected with intraperitoneal streptozotocin (STZ) after being fed by HSHFD for two months, TLR4-/- mice exhibited less weight loss than WT. Blocking TLR4 alleviated the changes in body weight and blood glucose, consequently reducing the efficiency of diabetes modeling, especially for male mice. Additionally, male TLR4-/- obese mice exhibit lower total cholesterol (TC) and low-density lipoprotein (LDL) levels in serum and less formation of fat droplets in the liver compared to WT. On the other hand, the knockout of TLR4 significantly increased the high-density lipoprotein (HDL) of male mice. This study should provide new insights into the role of TLR4, as well as opportunities to target novel approaches to the prevention and treatment of metabolic diseases like obesity and diabetes.

Fruit waste: a current perspective for the sustainable production of pharmacological, nutraceutical, and bioactive resources

Fruits are crucial components of a balanced diet and a good source of natural antioxidants, that have proven efficacy in various chronic illnesses. Various kinds of waste generated from fruit industries are considered a global concern. By utilizing this fruit waste, the international goal of "zero waste" can be achieved by sustainable utilization of these waste materials as a rich source of secondary metabolites. Moreover, to overcome this waste burden, research have focused on recovering the bioactive compounds from fruit industries and obtaining a new strategy to combat certain chronic diseases. The separation of high-value substances from fruit waste, including phytochemicals, dietary fibers, and polysaccharides which can then be used as functional ingredients for long-term health benefits. Several novel extraction technologies like ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE) could provide an alternative approach for successful extraction of the valuable bioactives from the fruit waste for their utilization as nutraceuticals, therapeutics, and value-added products. Most of these waste-derived secondary metabolites comprise polyphenols, which have been reported to have anti-inflammatory, insulin resistance-treating, cardiovascular disease-maintaining, probiotics-enhancing, or even anti-microbial and anti-viral capabilities. This review summarizes the current knowledge of fruit waste by-products in pharmacological, biological, and probiotic applications and highlights several methods for identifying efficacious bioactive compounds from fruit wastes.

Diabetic retinopathy: a comprehensive update on in vivo, in vitro and ex vivo experimental models

Diabetic retinopathy (DR), one of the leading causes of visual impairment and blindness worldwide, is one of the major microvascular complications in diabetes mellitus (DM). Globally, DR prevalence among DM patients is 25%, and 6% have vision-threatening problems among them. With the higher incidence of DM globally, more DR cases are expected to be seen in the future. In order to comprehend the pathophysiological mechanism of DR in humans and discover potential novel substances for the treatment of DR, investigations are typically conducted using various experimental models. Among the experimental models, in vivo models have contributed significantly to understanding DR pathogenesis. There are several types of in vivo models for DR research, which include chemical-induced, surgical-induced, diet-induced, and genetic models. Similarly, for the in vitro models, there are several cell types that are utilised in DR research, such as retinal endothelial cells, Müller cells, and glial cells. With the advancement of DR research, it is essential to have a comprehensive update on the various experimental models utilised to mimic DR environment. This review provides the update on the in vitro, in vivo, and ex vivo models used in DR research, focusing on their features, advantages, and limitations.

The Impact of Punica granatum Linn and Its Derivatives on Oxidative Stress, Inflammation, and Endothelial Function in Diabetes Mellitus: Evidence from Preclinical and Clinical Studies

Diabetes mellitus is recognized as the leading contributor to cardiovascular disease and associated mortality rates worldwide. Despite the use of pharmaceutical drugs to treat diabetes, its prevalence continues to rise alarmingly. Therefore, exploring remedies with a lower toxicity profile is crucial while remaining safe and effective in addressing this global public health crisis. Punica granatum Linn (pomegranate), known for its properties and safety profile, has been investigated in applied research and preclinical and clinical trials. However, conflicting reports still exist regarding its effects in diabetes. According to our knowledge, no systematic review has been conducted to critically analyze evidence from preclinical and clinical trials simultaneously, explicitly focusing on oxidative stress, inflammation, and endothelial function in diabetes. Therefore, in this systematic review, we searched for evidence on the impact of pomegranate in diabetes using databases such as PubMed, Scopus, and Google Scholar. Our inclusion criteria were limited to studies published in English. Of the 170 retrieved studies, 46 were deemed relevant and underwent critical analysis. The analyzed evidence suggests that pomegranate has the potential to alleviate oxidative stress, inflammation, and endothelial dysfunction in diabetes. Although a beneficial impact was noted in these markers, the endothelial function evidence still requires validation through further clinical trials with a powered sample size.

Lactobacillus paracasei IMC 502 ameliorates type 2 diabetes by mediating gut microbiota-SCFA-hormone/inflammation pathway in mice

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a complex and prevalent metabolic disease that seriously threatens human health. Numerous studies have shown that probiotics as dietary supplements have the potential to prevent and treat T2DM. However, the ability of various strains to improve diabetes symptoms and corresponding mechanisms are different. Thus, mechanistic investigation is required to validate the pharmacology of each probiotic strain for T2DM treatment. Lactobacillus paracasei IMC 502 was originally isolated from Italian elderly human feces and its probiotic attributes have been demonstrated. Here, the antidiabetic pharmacodynamics of L. paracasei IMC 502 on T2DM mice was explored.

RESULTS

Lactobacillus paracasei IMC 502 significantly decreased blood glucose, HbA1c and lipid levels, improved insulin resistance and glucose intolerance, regulated the mRNA/protein expression of key hepatic enzymes associated with gluconeogenesis, de novo lipogenesis and PI3K/Akt pathway, and repaired pancreatic and hepatic tissue damage. This probiotic conferred beneficial outcomes in the gut microbiome of diabetic mice, which induced transformation of short-chain fatty acids (SCFAs) and further enhanced the secretion of downstream hormones, and ultimately ameliorated the inflammatory response.

CONCLUSION

Lactobacillus paracasei IMC 502 prevents and alleviates T2DM by mediating the gut microbiota-SCFA-hormone/inflammation pathway. © 2022 Society of Chemical Industry.

Punica granatum L. Polyphenolic Extract as an Antioxidant to Prevent Kidney Injury in Metabolic Syndrome Rats

Introduction

Obesity and metabolic syndrome (MetS) constitute a rapidly increasing health problem and contribute to the development of multiple comorbidities like acute and chronic kidney disease. Insulin resistance, inappropriate lipolysis, and excess of free fatty acids (FFAs) are associated with glomerulus hyperfiltration and atherosclerosis. The important component of MetS, oxidative stress, is also involved in the destabilization of kidney function and the progression of kidney injury. Natural polyphenols have the ability to reduce the harmful effect of reactive oxygen and nitrogen species (ROS/RNS). Extract derived from Punica granatum L. is rich in punicalagin that demonstrates positive effects in MetS and its associated diseases. The aim of the study was to investigate the effect of bioactive substances of pomegranate peel to kidney damage associated with the MetS.

Methods

In this study, we compared biomarkers of oxidative stress in kidney tissue of adult male Zucker Diabetic Fatty (ZDF) rats with MetS and healthy controls that were treated with Punica granatum L. extract at a dose of 100 or 200 mg/kg. Additionally, we evaluated the effect of polyphenolic extract on kidney injury markers and remodeling. The concentration of ROS/RNS, oxLDL, glutathione (GSH), kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), metalloproteinase 2 and 9 (MMP-2, MMP-9), and the activity of superoxide dismutase (SOD) and catalase (CAT) were measured.

Results

The data showed significant differences in oxidative stress markers between treated and untreated MetS rats. ROS/RNS levels, oxLDL concentration, and SOD activity were lower, whereas CAT activity was higher in rats with MetS receiving polyphenolic extract. After administration of the extract, markers for kidney injury (NGAL, KIM-1) decreased.

Conclusion

Our study confirmed the usefulness of pomegranate polyphenols in the treatment of MetS and the prevention of kidney damage. However, further, more detailed research is required to establish the mechanism of polyphenol protection.

Aqueous extract of Polygonatum sibiricum ameliorates glucose and lipid metabolism via PI3K/AKT signaling pathway in high-fat diet and streptozotocin-induced diabetic mice

This study was aimed to investigate the protective effects and elucidate the mechanisms of aqueous extract of Polygonatum sibiricum (PSAE) on glucolipid metabolism during the development of type 2 diabetes (T2DM). C57BL/6J mice fed with 60% high-fat diet (HFD) combined with streptozotocin (STZ) injection to simulate the occurrence process of T2DM. PSAE was administered daily by oral gavage during the experiment. The results demonstrated the protective effects in mice supplied with PSAE on the indicators of glycolipid metabolism (body weight, fasting blood glucose, the area under the curve, hemoglobin A1c, serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, and liver triglyceride) compared with the Model group mice. Furthermore, PSAE can ameliorate insulin resistance in mice liver by activating phosphoinositide-3-kinase/protein kinase B (PI3K/AKT) pathway signaling. Overall, our research suggested that PSAE can effectively regulate glucose and lipid metabolism during the development of T2DM as an alternative functional food. PRACTICAL APPLICATIONS: Diabetes is a chronic metabolic disease which is characterized by abnormal metabolism of glucose and lipoid and nowadays it has been one of the most representative chronic systemic progressive metabolic diseases. Polygonatum sibiricum is a traditional Chinese galenical and it also can be used as food ingredients. PSAE is the aqueous extract of Polygonatum sibiricum. 34% polysaccharides were detected in PSAE and it can effectively regulate glucose and lipid metabolism during the development of T2DM in mice. Thus, PSAE might be a promising functional food for regulation of glucolipid metabolism and the study also provides a theoretical basis for the development and application of food about Polygonatum sibiricum.

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.

Oxidative stress-triggered pyroptosis mediates Candida albicans susceptibility in diabetic foot

An accumulating trend of research demonstrates that diabetic patients are susceptible to skin infections with Candida albicans, but the mechanism still remains unclear. The intense oxidative stress (OS) responses were occurred in the lesion of diabetic mice footpads after C. albicans infection. Localised skin infections would lead to more severe complications while the severity of the condition worsens or the inadequate treatment. Notably, in this study, through the investigation of murine diabetic footpad C. albicans infection model and molecular biotechnology, including histopathological staining, immunofluorescence (IF) staining, quantitative real-time PCR (qPCR), western blot (WB), flow cytometry (FCM), sandwich enzyme-linked immunosorbent assay (ELISA) assays, we found that intense OS responses in the footpad tissue not only mediated the activation of NF-κB protein complex, but also triggered downstream pyroptosis and apoptosis through NLRP3 inflammasome, which is one of the potential reasons for the severe condition of infectious skin injuries in diabetic mice. Caspase-1, a classical signal pathway protein in pyroptosis, could promote pore formation on cell membranes and the release of the cytokine after NLRP3 inflammasome activation. With intense immune-inflammatory responses, the organism also stimulates immune organs such as the spleen and lymph nodes to produce negative feedback regulation and generate CD4⁺CD25⁺Foxp3⁺ Treg cells to rectify the process. Therefore, combined with the results of this work, it is possible to design and screen relevant drugs for NLRP3 inflammasomes as core targets to keep the OS response at a low level in the footpad tissues.

Punicalagin protects against the development of pancreatic injury and insulitis in rats with induced T1DM by reducing inflammation and oxidative stress

Pancreatic inflammation and oxidative damage remain major concerns in type 1 diabetes mellitus (T1DM). Punicalagin, a major polyphenol in pomegranates, exhibited antioxidant and protective effects on several organs in case of T1DM; however, no study has yet explored the protective effects of punicalagin on the pancreas and islets of Langerhans. T1DM was induced by injecting 40 mg/kg streptozotocin (STZ) intraperitoneally. Punicalagin (1 mg/kg ip) was injected daily for 15 days after T1DM induction. In diabetic rats, punicalagin treatment lowered the levels of inflammatory biomarkers (monocyte chemoattractant protein-1 and C-reactive protein) and adhesion molecules (E-selectin, intercellular adhesion molecule, and vascular cell adhesion molecule) while activating myeloperoxidase activity. Treatment of diabetic rats with punicalagin improved glutathione content and superoxide dismutase, catalase, and glutathione peroxidase activities; upregulated serum paraoxonase-1 activity; and prevented the elevation lipid peroxidation and protein oxidation products in the pancreas. Furthermore, punicalagin protected the pancreas against STZ-induced histopathological alterations and increased immune-reactive β-cells while reducing leucocyte infiltration into the islets of Langerhans, leading to normalized blood glucose and insulin levels. These findings indicated that punicalagin might protect against the development of insulitis in T1DM. In conclusion, punicalagin exerts a strong protective effect on the pancreas against oxidative injury and inflammation in STZ-induced experimental T1DM. The present results recommend punicalagin as a potential adjuvant for reducing diabetes-associated insulitis.

Punicalagin Attenuates Neuronal Apoptosis by Upregulating 5-Hydroxymethylcytosine in the Diabetic Mouse Brain

Punicalagin exerts neuroprotective activity by improving AMP-activated kinase (AMPK) and mitochondrial Krebs cycle. AMPK and Krebs cycle metabolites regulate 5-hydroxymethylcytosine (5hmC) via acting on ten-eleven translocation (TET) enzymes. Therefore, we hypothesized that punicalagin inhibits diabetes-related neuronal apoptosis by upregulating 5hmC in the diabetic mouse brain. C57BL/6J mice aged 8 weeks were randomly separated into five groups (n = 10), normal control (NC), diabetes mellitus (DM), resveratrol (RES), low-dose punicalagin (LPU), and high-dose punicalagin (HPU). Compared with other groups, the neuronal apoptosis rate was significantly higher and the 5hmC level of the cerebral cortex was significantly lower in the DM group. The levels of TET2 and P-AMPKα/AMPKα were significantly lower in the DM group than in both LPU and HPU groups. The ratio of (succinic acid + fumaric acid)/α-ketoglutarate was significantly higher in the DM group than in other groups. The present results suggest that punicalagin upregulates 5hmC via activating AMPK and maintaining Krebs cycle homeostasis, thus inhibiting neuronal apoptosis in the diabetic mouse brain.

Potential Mechanisms of the Improvement of Glucose Homeostasis in Type 2 Diabetes by Pomegranate Juice

Pomegranate is a polyphenol-rich fruit. Studies have shown that extracts prepared from its juice or from different parts of the pomegranate plant have various biological activities including antioxidant, antimicrobial, anti-inflammatory, anticarcinogenic, cardioprotective, and antidiabetic. The therapeutic potential has been attributed to various phytochemicals, including ellagic acid, punicic acid, flavonoids, anthocyanidins, anthocyanins, flavonols, and flavones. This review focuses on the scientific evidence of pomegranate juice as hypoglycemic, emphasizing the chemical composition and the possible mechanisms of action associated with this effect. Studies were identified using the PubMed, Scopus, and ISI Web of Science databases to identify relevant articles focused on the hypoglycemic effect of pomegranate juice. The physiological responses to pomegranate juice are reported here, including a decrease of oxidative stress damage, an increase of insulin-dependent glucose uptake, maintenance of β-cell integrity, inhibition of nonenzymatic protein glycation, an increase of insulin sensitivity, modulation of peroxisome proliferator-activated receptor-gamma, inhibition of α-amylase, inhibition of α-glucosidase and dipeptidyl peptidase-4, and decreases in inflammation. Overall, we found a significant hypoglycemic effect of pomegranate in in vitro and in vivo studies and we summarize the potential mechanisms of action.

Punicalagin alleviates renal injury via the gut-kidney axis in high-fat diet-induced diabetic mice

Diabetic renal injury was associated with dysbiosis of the gut microbiota and intestinal barrier. Punicalagin (PU) from pomegranates potentially impacts the microbial ecosystem, intestinal barrier, and renal function. Therefore, we hypothesized that PU may improve diabetic renal injury by modulating the gut-kidney axis. The present study evaluated the effect of PU on the gut-kidney axis and kidney function in a diabetic renal injury mouse model induced by a high-fat diet (HFD). Mice were fed a HFD without PU or with at doses of 50 and 100 mg kg^-1 d^-1 for 8 weeks. Targeted metabolomics by GC-MS and 16S rRNA sequencing were implemented to determine short-chain fatty acids (SCFAs) and microbes. Further RNA sequencing analyses were performed to determine which differentially expressed genes were changed by PU. Compared with the DM model group, PU supplementation improved diabetic renal injury, ameliorated kidney architecture and function, and reshaped gut microbial ecology. Additionally, PU reversed HFD-induced gut barrier dysfunction, promoted cecal SCFA concentrations and inhibited serum lipopolysaccharide (LPS) and diamine oxidase (DAO) levels. Moreover, correlation analysis found that cecal SCFAs were significantly negatively correlated with inflammation-related genes in the kidney. The present results indicated that PU, a promising bioactive polyphenol, successfully improved diabetic renal injury, most likely through the gut-kidney axis.

Punicalagin prevents cisplatin-induced nephrotoxicity by attenuating oxidative stress, inflammatory response, and apoptosis in rats

Nephrotoxicity is a major complication that limits the therapeutic application of cisplatin (CIS). Oxidative stress and inflammation are implicated in CIS-induced acute kidney injury (AKI) and apoptotic cell death. Punicalagin (PUN), a polyphenol in pomegranate, possesses promising anti-inflammatory and antioxidant activities, and its beneficial effect against CIS-induced AKI has not been fully elucidated. This investigation evaluated the protective effect of PUN against CIS-induced renal oxidative stress, inflammation and cell death. Rats received PUN (25 and 50 mg/kg) for 10 days and a single injection of CIS at day 7. The results showed increased serum urea and creatinine and several histopathological alterations in the kidney of CIS-intoxicated rats. Renal malondialdehyde (MDA) and nitric oxide (NO) were increased, and reduced glutathione, superoxide dismutase and catalase were declined in rats treated with CIS. PUN effectively ameliorated kidney function and attenuated tissue injury induced by CIS, decreased MDA and NO, and enhanced antioxidant defenses. Additionally, PUN downregulated NF-κB p65, iNOS, TNF-α, IL-6 and IL-1β in the kidney of rats that received CIS. Bax and caspase-3 were increased, and Bcl-2 was decreased in the kidney of CIS-intoxicated rats, an effect that was reversed by PUN. PUN upregulated Nrf2 expression in the kidney of CIS-intoxicated rats. In conclusion, PUN prevents CIS-induced AKI in rats by attenuating oxidative stress, inflammatory response and apoptosis, and upregulating Nrf2 and antioxidants.

Omnifarious fruit polyphenols: an omnipotent strategy to prevent and intervene diabetes and related complication?

Diabetes mellitus is a metabolic syndrome which cannot be cured. Recently, considerable interest has been focused on food ingredients to prevent and intervene in complications of diabetes. Polyphenolic compounds are one of the bioactive phytochemical constituents with various biological activities, which have drawn increasing interest in human health. Fruits are part of the polyphenol sources in daily food consumption. Fruit-derived polyphenols possess the anti-diabetic activity that has already been proved either from in vitro studies or in vivo studies. The mechanisms of fruit polyphenols in treating diabetes and related complications are under discussion. This is a comprehensive review on polyphenols from the edible parts of fruits, including those from citrus, berries, apples, cherries, mangoes, mangosteens, pomegranates, and other fruits regarding their potential benefits in preventing and treating diabetes mellitus. The signal pathways of characteristic polyphenols derived from fruits in reducing high blood glucose and intervening hyperglycemia-induced diabetic complications were summarized.

Effects of L-arabinose by hypoglycemic and modulating gut microbiome in a high-fat diet- and streptozotocin-induced mouse model of type 2 diabetes mellitus

L-arabinose is a good and healthy food additive. This study was conducted to investigate the effect of L-arabinose in a mouse model of type 2 diabetes mellitus (T2DM) induced by exposure to a high-fat diet (HFD) and streptozotocin (STZ). The model mice received L-arabinose at 20 and 60 mg (kg body weight [bw])^-1 d^-1 , metformin at 300 mg (kg bw)^-1 d^-1 (positive control) or sterile water (control) via oral gavage. Compared with the model group, mice treated with L-arabinose exhibited attenuated symptoms of diabetes mellitus, including a slower rate of body weight loss, increased homeostasis model assessment of β-cell function index levels, decreased blood glucose, alleviation of steatosis, and repair of pancreatic islet cells. L-arabinose also exerted an anti-inflammatory effect and partially mitigated dyslipidemia. A 16S-rRNA sequence analysis of the gut microbiota revealed that at the phylum level, treatment with L-arabinose significantly reduced the ratio of Firmicutes to Bacteroidetes due to a decreased relative abundance of Firmicutes; at the genus level, it reversed the increase in the relative abundance of Allobaculum and the decrease abundance of Oscillospira caused by exposure to an HFD and STZ. And the model mice received L-arabinose at 20 mg (kg bw)^-1 d^-1 had a better effect on improving T2DM than the high-dose group supplemented L-arabinose at 60 mg (kg bw)^-1 d^-1 . These results strongly suggest L-arabinose as an excellent candidate supplement to prevent or treat T2DM. PRACTICAL APPLICATIONS: L-arabinose, xylitol and sucralose are well-known substitutes for sucrose. L-arabinose has been reported to have beneficial effects on hyperglycemia, glycemic index, and fat accumulation. In this study, we found that low-dose (20 mg (kg bw)^-1 d^-1 ) supplementation of L-arabinose significantly improved glucose intolerance and gut microbiota incoordination in T2DM caused by HFD and STZ.

Application of metabolomics for revealing the interventional effects of functional foods on metabolic diseases

Metabolomics is an important branch of systems biology, which can detect changes in the body's metabolism before and after the intervention of functional foods, identify effective metabolites, and predict the interventional effects and the mechanism. This review summarizes the latest research outcomes regarding interventional effects of functional foods on metabolic diseases via metabolomics analysis. Since metabolomics approaches are powerful strategies for revealing the changes in bioactive compounds of functional foods during processing and storage, we also discussed the effects of these parameters on functional food metabolites using metabolomics approaches. To date, a number of endogenous metabolites related to the metabolic diseases after functional foods intervention have been discovered. Unfortunately, the mechanisms of metabolic disease-related molecules are still unclear and require further studies. The combination of metabolomics with other omics technologies could further promote its ability to fully understand the precise biological processes of functional food intervention on metabolic diseases.

Natural Polyphenols in Metabolic Syndrome: Protective Mechanisms and Clinical Applications

Metabolic syndrome (MetS) is a chronic disease, including abdominal obesity, dyslipidemia, hyperglycemia, and hypertension. It should be noted that the occurrence of MetS is closely related to oxidative stress-induced mitochondrial dysfunction, ectopic fat accumulation, and the impairment of the antioxidant system, which in turn further aggravates the intracellular oxidative imbalance and inflammatory response. As enriched anti-inflammatory and antioxidant components in plants, natural polyphenols exhibit beneficial effects, including improving liver fat accumulation and dyslipidemia, reducing blood pressure. Hence, they are expected to be useful in the prevention and management of MetS. At present, epidemiological studies indicate a negative correlation between polyphenol intake and MetS incidence. In this review, we summarized and discussed the most promising natural polyphenols (including flavonoid and non-flavonoid drugs) in the precaution and treatment of MetS, including their anti-inflammatory and antioxidant properties, as well as their regulatory functions involved in glycolipid homeostasis.

Gut modulation based anti-diabetic effects of carboxymethylated wheat bran dietary fiber in high-fat diet/streptozotocin-induced diabetic mice and their potential mechanisms

We explored the effect of carboxymethylated wheat bran dietary fibers (DFs) on mice with type 2 diabetes (T2D) (induced by HFD combined with STZ) and their possible hypoglycemic mechanism. After feeding the diabetic mice with modified DFs for four weeks, the DFs had lipid lowering and anti-hyperglycemic effect, via increasing the levels of insulin, GLP-1, PYY, and SCFAs in diabetic mice, and improving the histopathology of liver and pancreas. qRT-PCR results showed that the intake of DFs up-regulated the expression levels of G6Pase and Prkce, and down regulated the expression levels of Glut2 and InsR in the liver of diabetic mice. It is suggested that DFs may play a role by inhibiting 1,2-DAG-PKCε pathway, improving insulin receptor activity and insulin signal transduction. 16 S rDNA high-throughput sequencing results showed that the DFs significantly improved the relative abundance of Akkermansia muciniphila, increased the diversity of gut microbiota and reduced the ratio of Firmicutes to Bacteroidetes, thus promoting the hypoglycemic and hypolipidemic effect on diabetic mice. Our study can foster the further understanding of the gut modulatory biomarkers and related metabolites, and may extend the basis for DFs as a potential dietary intervention to prevent or treat the T2D.

Sargassum fusiforme together with turmeric extract and pomegranate peel extract alleviates obesity in high fat-fed C57BL/6J mice

Sargassum fusiforme, a nutritious edible brown alga, has been widely suggested to play an important role in the development of functional food because of its multiple biological activities. The aim of this study was to explore the anti-obesity effect of the combination of Sargassum fusiforme with extracts of fruit and vegetable by comparing the effects of Sargassum fusiforme (S), Sargassum fusiforme together with pomegranate peel extract (SP), Sargassum fusiforme together with turmeric extract (ST) and Sargassum fusiforme together with turmeric extract and pomegranate peel extract (C) on diet-induced obese C57BL/6J mice. Long-term consumption of a high-fat diet can lead to high levels of blood lipid, increase adipocyte size, and cause lipid metabolism dysfunction and gut microbiota dysbiosis. According to the results of the experiments, SP and ST were more effective in reducing lipid levels and fat accumulation than S; and, C exhibited the strongest efficacy compared with the other three supplements. ST and C also regulated adipocytokines and had significant effects on the gene expression of lipid metabolism. We also found that C alleviated the imbalance of intestinal flora caused by a high-fat diet to a certain extent. In conclusion, SP, ST and C have anti-obesity potentials, which can be used as alternative ingredients in the formula of functional food for obese people.