Polyphenolic derivatives from mango (Mangifera Indica L.) modulate fecal microbiome, short-chain fatty acids production and the HDAC1/AMPK/LC3 axis in rats with DSS-induced colitis

Preventive effects of turmeric against HFD/STZ-induced type 2 diabetes in mice by activating IRS1/PI3K/Akt signaling in association with gut microbiota metabolism

This study is the first to investigate the antidiabetic effect of turmeric powder (TP) and its underlying molecular mechanism in type 2 diabetes mellitus (T2DM) mice. The T2DM mice were supplemented with or without TP (8%) for 8 weeks. The results indicated that the glucolipid metabolism disorder and insulin resistance in T2DM mice were significantly ameliorated through supplementation with TP. The consumption of TP also ameliorated the T2DM-induced gut microbiota dysbiosis, as reflected by a dramatic increase in the relative abundance of beneficial bacteria such as Bacteroides, Rikenella and Allobaculum at the genus level. Besides, TP significantly increased the colonic levels of short-chain fatty acids (SCFAs) and subsequently activated the IRS1/PI3K/Akt and AMPK-mediated gluconeogenesis signaling pathways to improve insulin resistance in T2DM mice. Interestingly, TP-activated IRS1/PI3K/Akt and AMPK-mediated gluconeogenesis signaling pathways were highly correlated with the reconstruction of the gut microbiome and the formation of SCFAs. Collectively, these findings, for the first time, highlight a novel antidiabetic mechanism of TP by alleviating intestinal microbiota dysbiosis and promoting SCFA production to trigger the IRS1/PI3K/Akt and AMPK-mediated gluconeogenesis signaling axis.

Promotion of Healthy Aging Through the Nexus of Gut Microbiota and Dietary Phytochemicals

Aging is associated with the decline of tissue and cellular functions, which can promote the development of age-related diseases like cancer, cardiovascular disease, neurodegeneration, and disorders of the musculoskeletal and immune systems. Healthspan is the length of time an individual is in good health and free from chronic diseases and disabilities associated with aging. Two modifiable factors that can influence healthspan, promote healthy aging, and prevent the development of age-related diseases, are diet and microbiota in the gastrointestinal tract (gut microbiota). This review will discuss how dietary phytochemicals and gut microbiota can work in concert to promote a healthy gut and healthy aging. First, an overview is provided of how the gut microbiota influences healthy aging through its impact on gut barrier integrity, immune function, mitochondria function, and oxidative stress. Next, the mechanisms by which phytochemicals effect gut health, inflammation, and nurture a diverse and healthy microbial composition are discussed. Lastly, we discuss how the gut microbiota can directly influence health by producing bioactive metabolites from phytochemicals in food like urolithin A, equol, hesperetin, and sulforaphane. These and other phytochemical-derived microbial metabolites that may promote healthspan are discussed. Importantly, an individual's capacity to produce health-promoting microbial metabolites from cruciferous vegetables, berries, nuts, citrus, and soy products will be dependent on the specific bacteria present in the individual's gut.

Lacticaseibacillus rhamnosus Fermentation Ameliorates Physicochemical Properties, Physiological Activity, and Volatile and Non-Volatile Compounds of Mango Juice: Preliminary Results at Laboratory Scale

Lacticaseibacillus rhamnosus is a strain predominantly used for juice production because of its excellent fermentation characteristics and strong acid production capacity. However, the influence of L. rhamnosus on the quality of mango juice has not yet been determined. Therefore, the effects of L. rhamnosus FJG1530 on the physicochemical properties, physiological activity, and volatile and non-volatile compounds of mango juice were extensively examined in this study. The data showed that L. rhamnosus FJG1530 possessed strong adaptability to mango juice, reducing its total sugar and increasing its total flavonoids. L. rhamnosus FJG1530 fermentation enhanced the ability of mango juice to clear the free radicals ABTS and DPPH, as well as improving the inhibition of lipase and α-glucosidase. In addition, L. rhamnosus FJG1530 treatment improved the volatile compounds in mango juice, especially promoting the formation of acids and alcohols. Simultaneously, metabolomic analysis revealed that 592 non-volatile compounds in mango juice were significantly changed by L. rhamnosus FJG1530 fermentation, with 413 dramatically increased and 179 significantly decreased metabolites. This study demonstrates that the fermentation process using L. rhamnosus FJG1530 was beneficial for ameliorating the quality of mango juice.

A review on the role of deep eutectic solvents in mango (Mangifera indica) extraction

The present review attempts to evaluate the applicability of deep eutectic solvents (DES) as a green technique for the extraction of phytochemicals from Mangifera indica L. and their therapeutic potential. Mango has been reported to show numerous therapeutic activities, which are attributed to its abundant source of bioactive compounds. Thus, the therapeutic potential of phytochemicals in mangoes is reviewed based on different reported bioactivity tests. The use of DESs is considered a green approach for the extraction of bioactive compounds from natural sources utilizing two or more components and a safe alternative for application in the nutritional, pharmaceutical and other sectors. The trends in the extraction of phytochemicals from mango using different DES components and different extraction parameters of the optimum protocol are reviewed. Hence, DESs are considered potential solvents with selective and efficient properties for extracting bioactive ingredients from mango. However, there are several knowledge gaps that need to be assessed for DES-based bioactive compound extraction from mango such as information on the local and specific varieties of mangoes, standardization of the extraction protocols and use of other parts of the mango plant as alternatives to its peel as bioactive sources. Accordingly, the extraction of bioactive compounds from mango using DESs will provide useful information for subsequent agricultural, pharmaceutical and nutraceutical applications in the future.

Potential interventions and interactions of bioactive polyphenols and functional polysaccharides to alleviate inflammatory bowel disease - A review

Inflammatory bowel disease is a multifaceted condition that is influenced by nutritional, microbial, environmental, genetic, psychological, and immunological factors. Polyphenols and polysaccharides have gained recognition for their therapeutic potential. This review emphasizes the biological effects of polyphenols and polysaccharides, and explores their antioxidant, anti-inflammatory, and microbiome-modulating properties in the management of inflammatory bowel disease (IBD). However, polyphenols encounter challenges, such as low stability and low bioavailability in the colon during IBD treatment. Hence, polysaccharide-based encapsulation is a promising solution to achieve targeted delivery, improved bioavailability, reduced toxicity, and enhanced stability. This review also discusses the significance of covalent and non-covalent interactions, and simple and complex encapsulation between polyphenols and polysaccharides. The administration of these compounds in appropriate quantities has proven beneficial in preventing the development of Crohn's disease and ulcerative colitis, ultimately leading to the management of IBD. The use of polyphenols and polysaccharides has been found to reduce histological scores and colon injury associated with IBD, increase the abundance of beneficial microbes, inhibit the development of colitis-associated cancer, promote the production of microbial end-products, such as short-chain fatty acids (SCFAs), and improve anti-inflammatory properties. Despite the combined effects of polyphenols and polysaccharides observed in both in vitro and in vivo studies, further human clinical trials are needed to comprehend their effectiveness on inflammatory bowel disease.

Molecular crosstalk between polyphenols and gut microbiota in cancer prevention

A growing body of evidence suggests that cancer remains a significant global health challenge, necessitating the development of novel therapeutic approaches. In recent years, the molecular crosstalk between polyphenols and gut microbiota has emerged as a promising pathway for cancer prevention. Polyphenols, abundant in many plant-based foods, possess diverse bioactive properties, including antioxidant, anti-inflammatory, and anticancer activities. The gut microbiota, a complex microbial community residing in the gastrointestinal tract, plays a crucial role in a host's health and disease risks. This review highlights cancer suppressive and oncogenic mechanisms of gut microbiota, the intricate interplay between gut microbiota modulation and polyphenol biotransformation, and the potential therapeutic implications of this interplay in cancer prevention. Furthermore, this review explores the molecular mechanisms underpinning the synergistic effects of polyphenols and the gut microbiota, such as modulation of signaling pathways and immune response and epigenetic modifications in animal and human studies. The current review also summarizes the challenges and future directions in this field, including the development of personalized approaches that consider interindividual variations in gut microbiota composition and function. Understanding the molecular crosstalk could offer new perspectives for the development of personalized cancer therapies targeting the polyphenol-gut axis. Future clinical trials are needed to validate the potential role of polyphenols and gut microbiota as innovative therapeutic strategies for cancer treatment.

Interactions between gut microbiota and polyphenols: A mechanistic and metabolomic review

BACKGROUND

Polyphenols are a class of naturally sourced compounds with widespread distribution and an extensive array of bioactivities. However, due to their complex constituents and weak absorption, a convincing explanation for their remarkable bioactivity remains elusive for a long time. In recent years, interaction with gut microbiota is hypothesized to be a reasonable explanation of the potential mechanisms for natural compounds especially polyphenols.

OBJECTIVES

This review aims to present a persuasive explanation for the contradiction between the limited bioavailability and the remarkable bioactivities of polyphenols by examining their interactions with gut microbiota.

METHODS

We assessed literatures published before April 10, 2023, from several databases, including Scopus, PubMed, Google Scholar, and Web of Science. The keywords used include "polyphenols", "gut microbiota", "short-chain fatty acids", "bile acids", "trimethylamine N-oxide", "lipopolysaccharides" "tryptophan", "dopamine", "intestinal barrier", "central nervous system", "lung", "anthocyanin", "proanthocyanidin", "baicalein", "caffeic acid", "curcumin", "epigallocatechin-3-gallate", "ferulic acid", "genistein", "kaempferol", "luteolin", "myricetin", "naringenin", "procyanidins", "protocatechuic acid", "pterostilbene", "quercetin", "resveratrol", etc. RESULTS: The review first demonstrates that polyphenols significantly alter gut microbiota diversity (α- and β-diversity) and the abundance of specific microorganisms. Polyphenols either promote or inhibit microorganisms, with various factors influencing their effects, such as dosage, treatment duration, and chemical structure of polyphenols. Furthermore, the review reveals that polyphenols regulate several gut microbiota metabolites, including short-chain fatty acids, dopamine, trimethylamine N-oxide, bile acids, and lipopolysaccharides. Polyphenols affect these metabolites by altering gut microbiota composition, modifying microbial enzyme activity, and other potential mechanisms. The changed microbial metabolites induced by polyphenols subsequently trigger host responses in various ways, such as acting as intestinal acid-base homeostasis regulators and activating on specific target receptors. Additionally, polyphenols are transformed into microbial derivatives by gut microbiota and these polyphenols' microbial derivatives have many potential advantages (e.g., increased bioactivity, improved absorption). Lastly, the review shows polyphenols maintain intestinal barrier, central nervous system, and lung function homeostasis by regulating gut microbiota.

CONCLUSION

The interaction between polyphenols and gut microbiota provides a credible explanation for the exceptional bioactivities of polyphenols. This review aids our understanding of the underlying mechanisms behind the bioactivity of polyphenols.

Dietary (poly)phenols mitigate inflammatory bowel disease: Therapeutic targets, mechanisms of action, and clinical observations

Inflammatory bowel diseases (IBD), which include Crohn's disease and ulcerative colitis, are a rapidly growing public health concern worldwide. These diseases are heterogeneous at the clinical, immunological, molecular, genetic, and microbial level, but characteristically involve a disrupted immune-microbiome axis. Shortcomings in conventional treatment options warrant the need for novel therapeutic strategies to mitigate these life-long and relapsing disorders of the gastrointestinal tract. Polyphenols, a diverse group of phytochemicals, have gained attention as candidate treatments due to their array of biological effects. Polyphenols exert broad anti-inflammatory and antioxidant effects through the modulation of cellular signaling pathways and transcription factors important in IBD progression. Polyphenols also bidirectionally modulate the gut microbiome, supporting commensals and inhibiting pathogens. One of the primary means by which gut microbiota interface with the host is through the production of metabolites, which are small molecules produced as intermediate or end products of metabolism. There is growing evidence to support that modulation of the gut microbiome by polyphenols restores microbially derived metabolites critical to the maintenance of intestinal homeostasis that are adversely disrupted in IBD. This review aims to define the therapeutic targets of polyphenols that may be important for mitigation of IBD symptoms, as well as to collate evidence for their clinical use from randomized clinical trials.

A review on the gastrointestinal protective effects of tropical fruit polyphenols

Tropical fruits are popular because of their unique, delicious flavors and good nutritional value. Polyphenols are considered to be the main bioactive ingredients in tropical fruits, and these exert a series of beneficial effects on the human gastrointestinal tract that can enhance intestinal health and prevent intestinal diseases. Moreover, they are distinct from the polyphenols in fruits grown in other geographical zones. Thus, the comprehensive effects of polyphenols in tropical fruits on gut health warrant in-depth review. This article reviews, first, the biological characteristics of several representative tropical fruits, including mango, avocado, noni, cashew apple, passion fruit and lychee; second, the types and content of the main polyphenols in these tropical fruits; third, the effects of each of these fruit polyphenols on gastrointestinal health; and, fourth, the protective mechanism of polyphenols. Polyphenols and their metabolites play a crucial role in the regulation of the gut microbiota, increasing intestinal barrier function, reducing oxidative stress, inhibiting the secretion of inflammatory factors and regulating immune function. Thus, review highlights the value of tropical fruits, highlighting their significance for future research on their applications as functional foods that are oriented to gastrointestinal protection.

Polyphenols and Ulcerative Colitis: An Exploratory Study of the Effects of Red Wine Consumption on Gut and Oral Microbiome in Active-Phase Patients

SCOPE

This paper explores the effects of moderate red wine consumption on the clinical status and symptomatology of patients with ulcerative colitis (UC), including the study of the oral and intestinal microbiome.

METHODS AND RESULTS

A case control intervention study in UC patients is designed. Intervention patients (n = 5) consume red wine (250 mL day-1 ) for 4 weeks whereas control patients (n = 5) do not. Moderate wine consumption significantly (p < 0.05) improves some clinical parameters related to serum iron, and alleviates intestinal symptoms as evaluated by the IBDQ-32 questionnaire. 16S rRNA gene sequencing indicate a non-significant (p > 0.05) increase in bacterial alpha diversity after wine intervention in both saliva and fecal microbiota. Additional comparison of taxonomic data between UC patients (n = 10) and healthy subjects (n = 8) confirm intestinal dysbiosis for the UC patients. Finally, analysis of fecal metabolites (i.e., phenolic acids and SCFAs) indicates a non-significant increase (p > 0.05) for the UC patients that consumed wine.

CONCLUSIONS

Moderate and regular red wine intake seems to improve the clinical status and symptoms of UC patients in the active phase of the disease. However, studies with a greater sample size are required to achieve conclusive results.

In Vivo Two-Photon Imaging Analysis of Dynamic Degradation of Hepatic Lipid Droplets in MS-275-Treated Mouse Liver

The accumulation of hepatic lipid droplets (LDs) is a hallmark of non-alcoholic fatty liver disease (NAFLD). Appropriate degradation of hepatic LDs and oxidation of complete free fatty acids (FFAs) are important for preventing the development of NAFLD. Histone deacetylase (HDAC) is involved in the impaired lipid metabolism seen in high-fat diet (HFD)-induced obese mice. Here, we evaluated the effect of MS-275, an inhibitor of HDAC1/3, on the degradation of hepatic LDs and FFA oxidation in HFD-induced NAFLD mice. To assess the dynamic degradation of hepatic LDs and FFA oxidation in fatty livers of MS-275-treated HFD C57BL/6J mice, an intravital two-photon imaging system was used and biochemical analysis was performed. The MS-275 improved hepatic metabolic alterations in HFD-induced fatty liver by increasing the dynamic degradation of hepatic LDs and the interaction between LDs and lysozyme in the fatty liver. Numerous peri-droplet mitochondria, lipolysis, and lipophagy were observed in the MS-275-treated mouse fatty liver. Biochemical analysis revealed that the lipolysis and autophagy pathways were activated in MS-275 treated mouse liver. In addition, MS-275 reduced the de novo lipogenesis, but increased the mitochondrial oxidation and the expression levels of oxidation-related genes, such as PPARa, MCAD, CPT1b, and FGF21. Taken together, these results suggest that MS-275 stimulates the degradation of hepatic LDs and mitochondrial free fatty acid oxidation, thus protecting against HFD-induced NAFLD.

Mesona chinensis Benth Polysaccharides Alleviate DSS-Induced Ulcerative Colitis via Inhibiting of TLR4/MAPK/NF-κB Signaling Pathways and Modulating Intestinal Microbiota

SCOPE

Ulcerative colitis (UC) is a severe disease of the intestinal tract. To investigate the role of TLR4/Mitogen-activated protein kinase (MAPK)/Nuclear factor kappa-B(NF-κB) pathways and intestinal flora in UC, and the protective mechanisms of Mesona chinensis Benth polysaccharides (MBP), potential therapeutic agents due to their diabetes-relieving, cancer-suppressing, and immunomodulatory properties.

METHODS AND RESULTS

A dextran sulfate sodium (DSS)-induced mouse colitis model is used for experiments; the histopathology, immunohistochemistry, and Western blotting's results suggest that MBP can alleviate the colitis symptoms, inhibits the overproduction of TNF-α, IL-1β, promote IL-10, reduces myeloperoxidase activity, and alleviates the inflammatory response probably by inhibiting the activation of TLR4/MAPK/NF-κB pathways. Furthermore, MBP improvs the ratio of Bcl-2/BAX, maintains the intestinal integrity by promoting the levels of zonulin occludin-1 (ZO-1), occluding and mucin mucin-2 (MUC-2), reduces the levels of endotoxin (ET), lipopolysaccharide binding protein (LBP) in serum, and oxidative stress in liver. Moreover, using 16S rRNA Gene Sequencing analysis, MBP regulates gut microbiota by decreasing the abundances of Helicobacter and Prevotella and increasing the abundances of Lactobacillus and Coprococcus, reverses microbiota dysbiosis caused by DSS.

CONCLUSION

These findings confirm the anti-inflammatory effects of MBP, restoration of the intestinal barrier and intestinal flora, and have therapeutic potential to attenuate the development of UC.

Garambullo (Myrtillocactus geometrizans): effect of in vitro gastrointestinal digestion on the bioaccessibility and antioxidant capacity of phytochemicals

Garambullo (Myrtillocactus geometrizans), endemic fruit from Mexico, contains several bioactive compounds (phenolic compounds, betalains, antioxidant fiber), highlighting it as a good functional food. In this research, the impact of the in vitro gastrointestinal digestion on phytochemical bioaccessibility from garambullo and its antioxidant capacity are studied. The fruit contained previously unidentified phytochemicals in the polar and non-polar extracts (acetone and hexane). The bioaccessibility decreased in the mouth and stomach for flavanones (up to 11.9 and 8.9%, respectively), isoflavones (up to 20.0 and 9.2%, respectively), flavonols (up to 15.2 and 15.7%, respectively), hydroxycinnamic acids (up to 21.7 and 13.1%, respectively), and betalains (up to 10.5 and 4.2%, respectively); hydroxybenzoic acids were increased (up to 752.8 and 552.6%, respectively), while tocopherols increased in the mouth (127.7%) and decreased in the stomach (up to 90.3%). In the intestinal phase, the digestible fraction showed low phytochemicals bioaccessibility, and some compounds were recovered in the non-digestible fraction. The antioxidant capacity decreased in different compartments of the gastrointestinal tract, being higher in the mouth (872.9, 883.6, 385.2, and 631.2 μmol TE per g dw by ABTS, DPPH, ORAC, and FRAP, respectively) and stomach (836.2, 942.1, 289.0, and 494.9 μmol TE per g dw ABTS, DPPH, ORAC, and FRAP, respectively). The results indicate that digestion positively or negatively affects compounds' bioaccessibility depending on their structural family, and the antioxidant capacity decreases but remains higher than other functional foods.

Effects of tea polysaccharides in combination with polyphenols on dextran sodium sulfate-induced colitis in mice

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Tea polysaccharides (TPS) and tea polyphenols (TPP) had synergic effect on colitis.

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TPP + TPS was more effective on alleviating symptom severity.

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TPP + TPS showed greater effects on promoting intestinal barrier function.

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TPP + TPS increased the relative abundance of Lactobacillaceae and Lactobacillus.

Both tea polysaccharides (TPS) and tea polyphenols (TPP) are promising in the treatment of inflammatory bowel disease (IBD). However, the effects of their combination against IBD are still unknown. In the present study, the therapeutic effects of TPS, TPP and TPS + TPP on dextran sodium sulfate-induced colitis in mice were investigated. Our results showed that administration of TPS + TPP achieved the best effects, followed by TPP and TPS, which were evidenced by the restoration of various physical signs (body weight, colon length and disease activity index) and the promoted intestinal barrier function (colon damage, mucin secretion and tight junction proteins expression). Furthermore, TPP and TPS decreased the relative abundance of Proteobacteria and Enterobacteriaceae, while TPP + TPS increased that of Lactobacillaceae and Lactobacillus. In conclusion, TPS together with TPP had greater effects on alleviating colitis and promoting intestinal barrier function. This result is interesting when developing functional foods against colitis.

In vitro digestion, absorption and biological activities of acylated anthocyanins from purple sweet potatoes (Ipomoea batatas)

Purple sweet potatoes (PSP) are widely used as color enhancers in food formulations. Investigations on the stability of PSP polyphenolics during simulated digestion and subsequent absorption in a Caco-2 cell monolayer model were accomplished. Measures of bioactive activities were also assessed in vitro. PSP whole polyphenolic extracts as a control (WC) were compared to isolates enriched in anthocyanins (AC) or non-anthocyanin phenolics (NAP). Anthocyanins were also alkali-hydrolyzed to remove acylated moieties. Compounds were subjected to simulated gastro-intestinal digestions where non-hydrolyzed anthocyanins showed higher stability compared to alkali-hydrolyzed. For many alkali-hydrolyzed anthocyanins, the transport through a Caco-2 cell monolayer was reduced. PSP fractions significantly increased the generation of reactive oxygen species in HT-29 cells and was suppressive in the CCD-18Co cells while down-regulated mRNA expression of inflammatory markers. Results indicate the importance of PSP composition and the effects of acyl moieties on anthocyanin stability and functional properties for food colors.

Phenolic Compounds Promote Diversity of Gut Microbiota and Maintain Colonic Health

The role of non-energy-yielding nutrients on health has been meticulously studied, and the evidence shows that a compound can exert significant effects on health even if not strictly required by the organism. Phenolic compounds are among the most widely studied molecules that fit this description; they are found in plants as secondary metabolites and are not required by humans for growth or development, but they can influence a wide array of processes that modulate health across multiple organs and systems. The lower gastrointestinal tract is a prime site of action of phenolic compounds, namely, by their effects on gut microbiota and colonic health. As with humans, phenolic compounds are not required by most bacteria but can be substrates of others; in fact, some phenolic compounds exert antibacterial actions. A diet rich in phenolic compounds can lead to qualitative and quantitative effects on gut microbiota, thereby inducing indirect health effects in mammals through the action of these microorganisms. Moreover, phenolic compounds may be fermented by the gut microbiota, thereby modulating the compounds bioactivity. In the colon, phenolic compounds promote anti-inflammatory, anti-oxidant and antiproliferative actions. The aim of the present review is to highlight the role of phenolic compounds on maintaining or restoring a healthy microbiota and overall colonic health. Mechanisms of action that substantiate the reported evidence will also be discussed.

A spotlight on underlying the mechanism of AMPK in diabetes complications

OBJECTIVE

Type 2 diabetes (T2D) is one of the centenarian metabolic disorders and is considered as a stellar and leading health issue worldwide. According to the International Diabetes Federation (IDF) Diabetes Atlas and National Diabetes Statistics, the number of diabetic patients will increase at an exponential rate from 463 to 700 million by the year 2045. Thus, there is a great need for therapies targeting functions that can help in maintaining the homeostasis of glucose levels and improving insulin sensitivity. 5' adenosine monophosphate-activated protein kinase (AMPK) activation, by various direct and indirect factors, might help to overcome the hurdles (like insulin resistance) associated with the conventional approach.

MATERIALS AND RESULTS

A thorough review and analysis was conducted using various database including MEDLINE and EMBASE databases, with Google scholar using various keywords. This extensive review concluded that various drugs (plant-based, synthetic indirect/direct activators) are available, showing tremendous potential in maintaining the homeostasis of glucose and lipid metabolism, without causing insulin resistance, and improving insulin sensitivity. Moreover, these drugs have an effect against diabetes and are therapeutically beneficial in the treatment of diabetes-associated complications (neuropathy and nephropathy) via mechanism involving inhibition of nuclear translocation of SMAD4 (SMAD family member) expression and association with peripheral nociceptive neurons mediated by AMPK.

CONCLUSION

From the available information, it may be concluded that various indirect/direct activators show tremendous potential in maintaining the homeostasis of glucose and lipid metabolism, without resulting in insulin resistance, and may improve insulin sensitivity, as well. Therefore, in a nut shell, it may be concluded that the regulation of APMK functions by various direct/indirect activators may bring promising results. These activators may emerge as a novel therapy in diabetes and its associated complications.

Amelioration of 5-fluorouracil-induced intestinal mucositis by Streptococcus thermophilus ST4 in a mouse model

Intestinal mucositis is a commonly encountered toxic side effect in patients undergoing 5-fluorouracil (5-FU)-based chemotherapy. Numerous studies have shown that probiotics enable improving chemotherapy-induced intestinal mucositis, but the beneficial effects of probiotics differ depending on the strain. Therefore, in the present studies we suggest that S. thermophilus ST4 separated from raw milk may assess mucoprotective activity in 5-FU-induced intestinal mucositis. In our causal-comparative study design, fifteen mice were randomized assigned into three groups (n = 5/each group): control group, 5-FU group and 5-FU+S. thermophilus ST4 group. The control group was orally administrated saline only, and the 5-FU group was followed by intraperitoneal injection of 5-FU for 3 days after 10-day saline administration, and the 5-FU+S. thermophilus ST4 group was intragastrically subjected for S. thermophilus ST4 once per day during the whole experiment, starting from the first day of the experiment, followed by 5-FU intraperitoneal injection for 3 days after 10-day S. thermophilus ST4 pretreatment. Diarrhea score, pro-inflammatory cytokines serum levels, intestinal histopathology and short chain fatty acid were assessed. Here, we demonstrated the beneficial effects of S. thermophilus ST4 derived from raw milk against 5-FU-induced intestinal mucositis, including body weight reduction, appetite loss and diarrhea. Intrinsically, S. thermophilus ST4 effectively maintained epithelium structure in small intestines and colons as well as reduced the intestinal inflammation. Besides, S. thermophilus ST4 significantly increased the expression of acetic acid, reinforcing the muco-protective effects. In conclusion, our results demonstrate that S. thermophilus ST4 supplementation ameliorates 5-FU-induced intestinal mucositis. This suggests probiotic may serve as an alternative therapeutic strategy for the prevention or management of 5-FU-induced mucositis in the future.

Mango (Mangifera indica L.) Polyphenols: Anti-Inflammatory Intestinal Microbial Health Benefits, and Associated Mechanisms of Actions

Mango is rich in polyphenols including gallotannins and gallic acid, among others. The bioavailability of mango polyphenols, especially polymeric gallotannins, is largely dependent on the intestinal microbiota, where the generation of absorbable metabolites depends on microbial enzymes. Mango polyphenols can favorably modulate bacteria associated with the production of bioactive gallotannin metabolites including Lactobacillus plantarum, resulting in intestinal health benefits. In several studies, the prebiotic effects of mango polyphenols and dietary fiber, their potential contribution to lower intestinal inflammation and promotion of intestinal integrity have been demonstrated. Additionally, polyphenols occurring in mango have some potential to interact with intestinal and less likely with hepatic enzymes or transporter systems. This review provides an overview of interactions of mango polyphenols with the intestinal microbiome, associated health benefits and underlying mechanisms.

Acetate stimulates lipogenesis via AMPKα signaling in rabbit adipose-derived stem cells

Acetate plays an important role in host lipid metabolism. However, the regulatory network underlying acetate-regulated lipometabolism remains unclear. The aim of this study was to determine whether any cross talk occurs among adenosine 5'-monophosphate-activated protein kinase (AMPK), mitogen-activated protein kinases (MAPKs) and acetate in regulating lipid metabolism. The compound C (an AMPK inhibitor), and SB203580 (a p38 MAPK inhibitor) were used to treat rabbit adipose-derived stem cells (ADSCs) with or without acetate, respectively. It indicated that acetate (6 mM) for 6 h increased the lipid deposition in rabbit ADSCs. Besides, acetate treatment (6 mM) increased significantly phosphorylated protein level of AMPKα and p38 MAPK, but not altered significantly the phosphorylated protein level of extracellular signaling-regulated kinase (ERK) and c-Jun aminoterminal kinase (JNK). The blocking of AMPKα signaling attenuated acetate-induced lipid accumulation, but not that of p38 MAPK signaling. In conclusion, our findings suggest that AMPKα signaling pathway is associated with acetate-induced lipogenesis.

The Emerging Role of Polyphenols in the Management of Type 2 Diabetes

Type 2 diabetes (T2D) is a fast-increasing health problem globally, and it results from insulin resistance and pancreatic β-cell dysfunction. The gastrointestinal (GI) tract is recognized as one of the major regulatory organs of glucose homeostasis that involves multiple gut hormones and microbiota. Notably, the incretin hormone glucagon-like peptide-1 (GLP-1) secreted from enteroendocrine L-cells plays a pivotal role in maintaining glucose homeostasis via eliciting pleiotropic effects, which are largely mediated via its receptor. Thus, targeting the GLP-1 signaling system is a highly attractive therapeutic strategy to treatment T2D. Polyphenols, the secondary metabolites from plants, have drawn considerable attention because of their numerous health benefits, including potential anti-diabetic effects. Although the major targets and locations for the polyphenolic compounds to exert the anti-diabetic action are still unclear, the first organ that is exposed to these compounds is the GI tract in which polyphenols could modulate enzymes and hormones. Indeed, emerging evidence has shown that polyphenols can stimulate GLP-1 secretion, indicating that these natural compounds might exert metabolic action at least partially mediated by GLP-1. This review provides an overview of nutritional regulation of GLP-1 secretion and summarizes recent studies on the roles of polyphenols in GLP-1 secretion and degradation as it relates to metabolic homeostasis. In addition, the effects of polyphenols on microbiota and microbial metabolites that could indirectly modulate GLP-1 secretion are also discussed.

A mango (Mangifera indica L.) juice by-product reduces gastrointestinal and upper respiratory tract infection symptoms in children

The study aimed to evaluate the effect of a mango juice by-product (JBP) on upper-respiratory and gastrointestinal tract infection symptoms in children (6-8 y) in a randomized, double-blind, parallel, case-control study. For two months, children drank either flavored water (control group) or a mango JBP-based beverage (0.04 g·ml^-1; treatment group); such beverage provided 1.1 g, 278.6 mg and 7.8 mg of dietary fiber, extractable polyphenols (mono-to-hepta galloyl hexosides, mangiferin), and hydrolysable polyphenols (ellagic/gallic acid) per portion, respectively. Mango JBP reduced the incidence of gastrointestinal (flatulencies and abdominal inflammation; p ≤ 0.007) and upper-tract respiratory (crystalline mucus, itchy throat, runny nose, itchy nose, and sneezing; p ≤ 0.038) and such benefits were associated to increased serum levels of PAI-I, MIP-1a, and MIP-1b (p ≤ 0.04) and decreased levels of IgG, MIF, and osteopontin (p ≤ 0.01). We concluded that JBP-based beverage has immunomodulatory properties, useful to prevent or even treat common infectious diseases in school-age children.

Interaction of dietary polyphenols and gut microbiota: Microbial metabolism of polyphenols, influence on the gut microbiota, and implications on host health

The human gastrointestinal tract is inhabited by a vast number of microorganisms that are called as the microbiota. Each individual harbors a unique gut microbial composition, this composition evolves throughout the host's lifetime and it is easily affected by internal or external changes. It has been shown that gut microbiota plays a crucial role in host's health and as this complex community has the ability to interact with each other and with the host's immune system, the presence or absence of some major species can affect the homeostasis. Diet can be considered as one of the pivotal factors in modulating the functionality, integrity, and composition of the gut microbiota as the gastrointestinal tract is the first organ exposed to components of the diet. In this review, we have focused on the effects of polyphenols, key compounds of a healthy diet with several biological activities, on the gut microbial composition, their biotransformation by the gut microbiota, and the effect of their reciprocal interactions in human health and disease.

Galangin Protects against Symptoms of Dextran Sodium Sulfate-induced Acute Colitis by Activating Autophagy and Modulating the Gut Microbiota

Galangin is a natural flavonoid that has been reported to provide substantial health benefits. Nevertheless, little is known about the potential effects of galangin against inflammatory bowel diseases. Here, an in vivo study was performed to investigate the preventive effects of galangin against dextran sulphate sodium (DSS)-induced acute murine colitis, which mimics the symptoms of human ulcerative colitis (UC). Pre-treatment with galangin (15 mg/kg, p.o.) resulted in a significant decreased in the macroscopic signs of DSS-induced colitic symptoms, including a decreased disease activity index, prevention of the colon length shortening, and alleviation of the pathological changes occurring in the colon. Colonic pro-inflammatory mediators, including tumor necrosis factor-alpha, interleukin (IL)-1 beta, and IL-6, as well as myeloperoxidase activities were decreased following galangin pre-treatment when compared with the DSS control group. Moreover, galangin pre-treatment significantly increased the expressions of autophagy-related proteins and promoted the formation of autophagosome in the colon. Galangin pre-treatment increased the diversity of the gut microbiota, and this was accompanied by increased levels of short-chain fatty acids. These observed changes could involve the modulating effects conferred by galangin in relation to some specific bacteria populations, including the recovery of Lactobacillus spp., and increased Butyricimonas spp. Overall, these results support the use of galangin in the prevention of UC.

Mango (Mangifera indica L.) polyphenols reduce IL-8, GRO, and GM-SCF plasma levels and increase Lactobacillus species in a pilot study in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) characterized by chronic intestinal inflammation and intestinal microbial dysbiosis present a major risk factor in the development of colorectal cancer. Previously, dietary polyphenols from mango (Mangifera indica L.) such as gallotannins and gallic acid have been shown to mitigate intestinal inflammation and carcinogenesis, as well as modulate intestinal microbial composition. To further translate findings from preclinical models, we hypothesized that mango polyphenols possess anti-inflammatory and microbiome-modulatory activities and may improve symptoms of IBD, reduce biomarkers for inflammation and modulate the intestinal microbiome when administered as an adjuvant treatment in combination with conventional medications in patients with mild to moderate IBD. In this study, ten participants received a daily dose of 200-400 g of mango pulp for 8 weeks (NCT02227602). Mango intake significantly improved the primary outcome Simple Clinical Colitis Activity Index (SCCAI) score and decreased the plasma levels of pro-inflammatory cytokines including interleukin-8 (IL-8), growth-regulated oncogene (GRO) and granulocyte macrophage colony-stimulating factor (GM-CSF) by 16.2% (P = .0475), 25.0% (P = .0375) and 28.6% (P = .0485), all factors related to neutrophil-induced inflammation, respectively. Mango intake beneficially altered fecal microbial composition by significantly increasing the abundance of Lactobacillus spp., Lactobacillus plantarum, Lactobacillus reuteri and Lactobacillus lactis, which was accompanied by increased fecal butyric acid production. Therefore, enriching diet with mango fruits or potentially other gallotannin-rich foods seems to be a promising adjuvant therapy combined with conventional medications in the management of IBD via reducing biomarkers of inflammation and modulating the intestinal microbiota.

An orally administered butyrate-releasing xylan derivative reduces inflammation in dextran sulphate sodium-induced murine colitis

Butyrate has been shown to be effective in ulcerative colitis (UC). However, its oral administration is rare due to its rancid odour and unpleasant taste. In this study, the effect of a butyrate-releasing polysaccharide derivative, xylan butyrate ester (XylB), was evaluated in a dextran sodium sulphate (DSS)-induced UC model in C57BL/6 mice. Linear xylan was extracted from corn cobs. The C-2 and C-3 positions of the linear xylan were esterified with butyrate, forming XylB. The protective and therapeutic effects of XylB against UC were determined in a DSS-induced mouse model. The results showed that XylB treatments reversed the imbalance between pro- and anti-inflammatory cytokines. Moreover, XylB rebalanced the gut microbiota that interfered with DSS treatment and significantly decreased the relative abundance of the genera Oscillibacter, Ruminococcaceae UCG-009, Erysipelatoclostridium, and Defluviitaleaceae UCG-01. XylB increased butyrate content in the colon, upregulated G-protein coupled receptor 109A protein expression, inhibited histone deacetylase (HDAC) activity, and exerted anti-inflammatory activity through autophagy pathway activation and nuclear factor-κB (NF-κB) inhibition. XylB reduces inflammatory intestinal damage in mice, suggesting that it would be a potential drug for the treatment of UC and could be used to overcome the limitations of the oral administration of sodium butyrate.

Body Mass Index as a Determinant of Systemic Exposure to Gallotannin Metabolites during 6-Week Consumption of Mango (Mangifera indica L.) and Modulation of Intestinal Microbiota in Lean and Obese Individuals

SCOPE

This human clinical pilot trial investigated pharmacokinetics of gallotannin-metabolites and modulation of intestinal microbiota in healthy lean and obese individuals after 6 weeks of daily mango consumption.

METHODS AND RESULTS

Participants are divided into three groups: Lean Mango (LM: n = 12; BMI = 22.9 kg m^-2 ), Obese Mango (OM: n = 9; BMI = 34.6 kg m^-2 ), and Lean Control (LC: n = 11; BMI = 22.1 kg m^-2 ). LM and OM consumed 400 g of mango per day for 6 weeks. LC consumed mango only on Days 0 and 42. After 6 weeks, LM experienced increased systemic exposure (AUC_0-8h ) to gallotannin-metabolites, 1.4-fold (p = 0.043). The greatest increase is 4-O-methyl-gallic acid, 3.3-fold (p = 0.0026). Cumulative urinary excretion of gallotannin-metabolites significantly increased in LM and OM, but not LC. For OM, qPCR data show increased levels of tannase-producing Lactococcus lactis and decreased levels of Clostridium leptum and Bacteroides thetaiotaomicron, bacteria associated with obesity. LM experienced an increased trend of fecal levels of butyric (1.3-fold; p = 0.09) and valeric acids (1.5-fold; p = 0.056). Plasma endotoxins showed a decreased trend in LM and OM.

CONCLUSION

Continuous mango intake significantly increased systemic exposure to gallotannin- metabolites and induced an increased trend for fecal short-chain fatty acids in lean but not obese individuals. This pharmacokinetic discrepancy may result in BMI-associated reduced gallotannin-derived health benefits.