Effects of Nigella sativa seed polysaccharides on type 2 diabetic mice and gut microbiota

Edible herbal source-derived polysaccharides as potential prebiotics: Composition, structure, gut microbiota regulation, and its related health effects

Recently, with changes in dietary patterns, there has been increased interest in the concept of food and medicine homology, which can help prevent disease development. This has led to a growing focus on the development of functional health foods derived from edible herbal sources. Polysaccharides, found in many edible herbal sources, are gaining popularity as natural ingredients in the production of functional food products. The gut microbiota can effectively utilize most edible herbal polysaccharides (EHPs) and produce beneficial metabolites; therefore, the prebiotic potential of EHPs is gradually being recognized. In this review, we comprehensively discuss the structural features and characterization of EHPs to promote gut microbiota regulation as well as the structure-activity relationship between EHPs and gut microbiota. As prebiotics, intestinal microbiota can use EHPs to indirectly produce metabolites such as short-chain fatty acids to promote overall health; on the other hand, different EHP structures possess some degree of selectivity on gut microbiota regulation. Moreover, we evaluate the functionality and mechanism underlying EHPs in terms of anticancer activity, antimetabolic diseases, anti-inflammatory activity, and anti-neuropsychiatric diseases.

Blended Tea Ameliorates T2DM via Modulation of Gut Microflora

Increasing evidences suggest that type 2 diabetes mellitus (T2DM) is closely related to gut microflora dysbiosis, which can be improved by dietary intervention. Four natural plant products, including Cyclocarya paliurus, Fu brick tea, Ampelopsis grossedentata, and Lithocarpus litseifolius, were blended to form a blended tea product for obtaining the better flavor. The blended tea was also expected to have excellent pharmacological activity. Therefore, the ameliorative effect of blended tea on T2DM and underlying mechanisms were studied in this study. The results showed that the blended tea extract effectively attenuated the symptoms of glucose and lipid metabolism-related disorders in T2DM mice fed by high-fat and high-sucrose diet. Furthermore, blended tea extract intervention significantly attenuated gut microbiota dysbiosis, the abundance of bacteria such as Bacteroidetes and Firmicutes, which aid in the hydrolysis and utilization of carbohydrates, significantly increased, while the abundance of pathogenic bacteria such as Proteobacteria significantly decreased. Certain core microorganisms involved in energy metabolism, including Ruminococcaceae_UCG-005, Butyricimonas, Roseburia, Oscillibacter, [Eubacterium]_nodatum_group, Muribaculaceae, Prevotellaceae UCG 001, were also found to be improved by blended tea extract. Collectively, our results demonstrated that the blended tea may ameliorate T2DM through modulation of gut microflora. The blended tea may serve as novel functional drink for the treatment of T2DM and dysbiosis of gut microbiota.

The effect of the molecular weight of blackberry polysaccharides on gut microbiota modulation and hypoglycemic effect in vivo

Blackberry polysaccharides with certain molecular weight distribution have good bioactivity. In this research, type 2 diabetes mice were used to investigate the hypoglycemic effect of blackberry polysaccharides with three different molecular weights, BBP (603.59 kDa), BBP-8 (408.13 kDa) and BBP-24 (247.62 kDa), through gut microbiota modulation. Blackberry polysaccharides exhibited stronger hypoglycemic activity after degradation, and the FBG of BBP, BBP-8 and BBP-24 was reduced to 20.21 ± 4.17 mmol L-1, 20.6 ± 7.23 mmol L-1 and 17.32 ± 6.59 mmol L-1 and OGTT-AUC was reduced by 14.76%, 19.80% and 25.04%, respectively, after 8-week intervention. Furthermore, 16S rRNA gene sequencing analysis indicated that BBP, BBP-8 and BBP-24 could reshape the diversity and composition of the gut microbiota. From 0 to 4 weeks, the F/B of BBP, BBP-8 and BBP-24 reduced by 56.44%, 47.19% and 62.04%, reaching 3.39, 6.54, and 3.11 in the 8th week, respectively, which suggested the faster utilization of BBP-24. Moreover, the intervention the three blackberry polysaccharides increased the relative abundance of the targeted beneficial bacteria Oscillospira and Bacteroidaceae Bacteroides and decreased the relative abundance of the pathogenic bacterium Allobaculum. In general, the result demonstrated that blackberry polysaccharides with a lower molecular weight are more easily fermented, making the theoretical basis for the development of blackberry polysaccharides as a probiotic food to rapidly regulate intestinal flora for type 2 diabetes.

Advances in the treatment of type 2 diabetes mellitus by natural plant polysaccharides through regulation of gut microbiota and metabolism: A review

The prevalence and impact of type 2 diabetes mellitus (T2DM) is a major global health problem. The treatment process of T2DM is long and difficult to cure. Therefore, it is necessary to explore alternative or complementary methods to deal with the various challenges brought by T2DM. Natural plant polysaccharides (NPPs) have certain potential in the treatment of T2DM. However, many studies have not considered the relationship between the structure of NPPs and their anti-T2DM activity. This paper reviews the relevant anti-T2DM mechanisms of NPPs, including modulation of insulin action, promotion of glucose metabolism and modulation of postprandial glucose levels, anti-inflammation and modulation of gut microbiota (GM) and metabolism. This paper provides an in-depth study of the conformational relationships of NPPs and facilitates the development of anti-T2DM drugs or dietary supplements with NPPs.

Potential Protective Effect of Selenium-Enriched Lactobacillus plantarum on Cadmium-Induced Liver Injury in Mice

Cadmium (Cd) is a prevalent environmental contaminant that poses a potential hazard to the health of both humans and animals. In this study, biosynthesized selenium-enriched Lactobacillus plantarum and selenium nanoparticles (SeNPs) were developed and evaluated for their protective effects against Cd-induced hepatic injury in mice through oral administration for 4 weeks. Cadmium exposure resulted in severe impairment of liver function, as evidenced by increased levels of serum markers of liver injury and, oxidative stress and significant damage to liver tissue, and a notable decrease in the diversity of the intestinal microbiota. Oral administration of Se-enriched L. plantarum (LS) reduced cadmium accumulation in the liver by 49.5% and, restored other cadmium-induced damage markers to normal levels. A comparison of the effects with those of L. plantarum (L) and SeNPs isolated from LS revealed that LS could more effectively alleviate hepatic oxidative stress and reduce the intrahepatic inflammatory responses of the liver, further protecting against cadmium-induced liver injury. These findings suggest that the development of LS may be effective at protecting the liver and intestinal tract from cadmium-induced damage.

Updated Progress on Polysaccharides with Anti-Diabetic Effects through the Regulation of Gut Microbiota: Sources, Mechanisms, and Structure-Activity Relationships

Diabetes mellitus (DM) is a common chronic metabolic disease worldwide. The disturbance of the gut microbiota has a complex influence on the development of DM. Polysaccharides are one type of the most important natural components with anti-diabetic effects. Gut microbiota can participate in the fermentation of polysaccharides, and through this, polysaccharides regulate the gut microbiota and improve DM. This review begins by a summary of the sources, anti-diabetic effects and the gut microbiota regulation functions of natural polysaccharides. Then, the mechanisms of polysaccharides in regulating the gut microbiota to exert anti-diabetic effects and the structure-activity relationship are summarized. It is found that polysaccharides from plants, fungi, and marine organisms show great hypoglycemic activities and the gut microbiota regulation functions. The mechanisms mainly include repairing the gut burrier, reshaping gut microbiota composition, changing the metabolites, regulating anti-inflammatory activity and immune function, and regulating the signal pathways. Structural characteristics of polysaccharides, such as monosaccharide composition, molecular weight, and type of glycosidic linkage, show great influence on the anti-diabetic activity of polysaccharides. This review provides a reference for the exploration and development of the anti-diabetic effects of polysaccharides.

Oxidized konjac glucomannan: A safe dietary fiber influencing mouse gut microbiota

In this 13-week study, the potential effects of oxidized konjac glucomannan (OKGM) on ICR mice's metabolic health and gut microbiota were investigated and contrasted with enzyme-hydrolyzed KGM (EKGM) at a same molecular weight. Mice were fed diets containing 0 %, 2.5 %, 5.0 %, and 7.5 % of OKGM for 13 weeks. Results indicated that OKGM induced no adverse effects, with overall health, body weight gain, food consumption, and clinical pathology parameters being comparable to the control group. The no-observed-adverse-effect-level for OKGM was determined at 7.5 % in the diet, corresponding to 10.21 and 12.01 g/kg/day for male and female mice, respectively. OKGM intake positively regulated gut microbiota, characterized by a reduction in the relative abundance of Firmicutes, an increase in Bacteroidetes, and an enhanced presence of Lactobacillus, particularly Lactobacillus reuteri. In comparison, EKGM differently modulated the microbiota, notably increasing Muribaculaceae. These findings suggest that OKGM has the potential to be a functional food additive.

Antidiabetic effects and mechanism of γ-polyglutamic acid on type II diabetes mice

Diabetes is one of the foremost chronic non-communicable diseases worldwide, which significantly impacts people's quality of life. This study aimed to investigate the hypoglycemic effects of γ-polyglutamic acid (γ-PGA) on STZ-induced type II diabetes mice and its potential mechanisms. The results indicated that γ-PGA intervention contributed to reducing fasting blood glucose levels in diabetic mice, regulating lipid metabolism in type II diabetes mice, and improving insulin resistance. Additionally, γ-PGA could alleviate liver inflammation, enhancing the activity of hepatic antioxidant enzymes. Investigation into the insulin signaling pathway revealed that γ-PGA significantly increased the expression of INSR, IRS-1, Akt, PI3K in diabetic mice, thereby enhancing insulin sensitivity and improving insulin resistance to regulate glucose metabolism. High-throughput sequencing of mouse gut microbiota using 16S rRNA showed that γ-PGA increased the abundance and evenness of beneficial bacteria in the intestines of type II diabetic mice, inhibited the growth of harmful bacteria, and may exerted hypoglycemic effects by modulating and improving relevant metabolic pathways associated with diabetes symptoms. This study provides new insights into the treatment of type II diabetes and highlights the significant potential of γ-PGA in treating type II diabetes.

Laminaria japonica polysaccharide alleviates type 2 diabetes by regulating the microbiota-gut-liver axis: A multi-omics mechanistic analysis

The hypoglycemic effects of low-molecular-weight Laminaria japonica polysaccharide (LJO) were investigated in type 2 diabetes mellitus (T2DM) mice, focusing on its effect on the microbiome, metabolome, and transcriptome. The findings demonstrated that LJO significantly reduced fasting blood glucose levels, insulin levels, and inflammatory factors. Additionally, LJO induced changes in gut microbiota composition and increased the concentrations of cecal short-chain fatty acids. Analysis of transcriptomics and metabolomics data revealed that LJO primarily altered the endocrine and digestive systems, signal transduction, and lipid metabolism. It led to a decrease in palmitic acid levels and an increase in glutathione levels. Real-time quantitative polymerase chain reaction assay suggested that LJO upregulated Irs1 expression, consequently reducing insulin resistance. These findings strongly suggest that LJO holds promise in ameliorating T2DM and may serve as a potential dietary supplement for patients with T2DM.

New strategies for evaluating imidacloprid-induced biological consequences targeted to Eisenia fetida species and the corresponding mechanisms of its toxicity

Imidacloprid (IMI), a neonicotinoid insecticide, has a wide variety of applications in both agriculture and horticulture. As a result of it massive and repeated use, its traces remained in soil pose severe damage to soil invertebrates, particularly earthworms. Limited information is available regarding the underlying mechanisms of IMI toxicity toward earthworms at the molecular, transcriptional, and cellular levels. Here, Eisenia fetida coelomocytes and key defensive proteins were selected as targeted receptors to explore the toxic mechanisms of oxidative stress-mediated cytotoxicity, genotoxicity, and antioxidant responses induced by IMI stress and the molecular mechanisms underlying the binding of IMI and superoxide dismutase (SOD)/catalase (CAT). Results showed that IMI exposure destroyed the cell membrane integrity of earthworm cells, causing cell damage and cytotoxicity. The intracellular levels of ROS, including ·O2- and H2O2 were induced by IMI exposure, thereby triggering oxidative stress and damage. Moreover, IMI exposure attenuated the antioxidative stress responses (reduced antioxidant capacity and CAT/SOD activities) and caused deleterious effects (enhanced DNA damage, lipid peroxidation (LPO), and protein carbonylation (PCO)) through ROS-mediated oxidative stress pathway. Aberrant gene expression associated with oxidative stress and defense regulation, including CAT, CRT, MT, SOD, GST, and Hsp70 were induced after IMI exposure. Concentration-dependent conformational and structural alterations of CAT/SOD were observed when IMI binding. Also, direct binding of IMI resulted in significant inhibition of CAT/SOD activities in vitro. Molecular simulation showed that IMI preferred to bind to CAT active center through its direct binding with the key residue Tyr 357, while IMI bound more easily to the connecting cavity of two subunits away from SOD active center. In addition, hydrogen bonds and hydrophobic force are the main driving force of IMI binding with CAT/SOD. These findings have implications for comprehensive evaluation of IMI toxicity to soil eco-safety and offer novel strategies to elucidate the toxic mechanisms and pathways of IMI stress.

An Exploratory Review on the Hypoglycemic Action of Unani Anti-diabetic Drugs via Possible Modulation of Gut Microbiota

BACKGROUND AND AIM

Diabetes mellitus is a chronic, multi-factorial metabolic disorder and also an important public health issue that requires multi-dimensional therapeutic strategies for effective control. Unani herbs have long been used to effectively mitigate diabetes through various mechanisms. In recent years, it has been speculated that the alteration of gut microbiome ecology is potentially one of the important mechanisms through which the Unani drugs exert hypoglycemic action. This review aims at the trans-disciplinary interpretation of the holistic concepts of the Unani system of medicine and the molecular insights of contemporary medicine for novel strategies for diabetes management.

METHODOLOGY

We searched scientific databases such as PubMed, Google Scholar, and Science-Direct, etc. Unani classical texts (Urdu, Arabic, and Persian), and medical books, for diabetic control with Unani medicine through the gut microbiome.

RESULTS

Unani medicine defines, diabetes as a urinary system disorder disrupting the transformational faculty (Quwwat Mughayyira) in the gastrointestinal tract. The Unani system and contemporary biomedicine use different epistemology and ontology for describing diabetes through gutderived factors in whole-body glucose homeostasis. Unani Pharmaceutics have reported in clinical and preclinical (in vitro/ in vivo) trials in improving diabetes by altering gut microbiota composition, microvascular dysfunction, and inflammation. However, the preventive plan is the preservance of six essential factors (Asbāb Sitta Ḍarūriyya) as a lifestyle plan.

CONCLUSION

This is the first study on the integrative strategy about the hypoglycemic effects of Unani herbs that could serve as a prerogative novel approach for cost-effective, holistic, rationalistic, and multi-targeted diabetes management.

Emodin ameliorates doxorubicin-induced cardiotoxicity by inhibiting ferroptosis through the remodeling of gut microbiota composition

The relationship between gut microbiota and doxorubicin-induced cardiotoxicity (DIC) is becoming increasingly clear. Emodin (EMO), a naturally occurring anthraquinone, exerts cardioprotective effects and plays a protective role by regulating gut microbiota composition. Therefore, the protective effect of EMO against DIC injury and its underlying mechanisms are worth investigating. In this study, we analyzed the differences in the gut microbiota in recipient mice transplanted with different flora using 16S-rDNA sequencing, analyzed the differences in serum metabolites among groups of mice using a nontargeted gas chromatography-mass spectrometry coupling system, and assessed cardiac function based on cardiac morphological staining, cardiac injury markers, and ferroptosis indicator assays. We found EMO ameliorated DIC and ferroptosis, as evidenced by decreased myocardial fibrosis, cardiomyocyte hypertrophy, and myocardial disorganization; improved ferroptosis indicators; and the maintenance of normal mitochondrial morphology. The protective effect of EMO was eliminated by the scavenging effect of antibiotics on the gut microbiota. Through fecal microbiota transplantation (FMT), we found that EMO restored the gut microbiota disrupted by doxorubicin (DOX) to near-normal levels. This was evidenced by an increased proportion of Bacteroidota and a decreased proportion of Verrucomicrobiota. FMT resulted in changes in the composition of serum metabolites. Mice transplanted with EMO-improved gut microbiota showed better cardiac function and ferroptosis indices; however, these beneficial effects were not observed in Nrf2 (Nfe2l2)-/- mice. Overall, EMO exerted a protective effect against DIC by attenuating ferroptosis, and the above effects occurred by remodeling the composition of gut microbiota perturbed by DOX and required Nrf2 mediation.NEW & NOTEWORTHY This study demonstrated for the first time the protective effect of emodin against DIC and verified by FMT that its cardioprotective effect was achieved by remodeling gut microbiota composition, resulting in attenuation of ferroptosis. Furthermore, we demonstrated that these effects were mediated by the redox-related gene Nrf2.

Research progress on the hypoglycemic activity and mechanisms of natural polysaccharides

The incidence of diabetes, as a metabolic disease characterized by high blood sugar levels, is increasing every year. The predominantly western medicine treatment is associated with certain side effects, which has prompted people to turn their attention to natural active substances. Natural polysaccharide is a safe and low-toxic natural substance with various biological activities. Hypoglycemic activity is one of the important biological activities of natural polysaccharides, which has great potential for development. A systematic review of the latest research progress and possible molecular mechanisms of hypoglycemic activity of natural polysaccharides is of great significance for better understanding them. In this review, we systematically reviewed the relationship between the hypoglycemic activity of polysaccharides and their structure in terms of molecular weight, monosaccharide composition, and glycosidic bonds, and summarized underlying molecular mechanisms the hypoglycemic activity of natural polysaccharides. In addition, the potential mechanisms of natural polysaccharides improving the complications of diabetes were analyzed and discussed. This paper provides some valuable insights and important guidance for further research on the hypoglycemic mechanisms of natural polysaccharides.

Pectin from Citrus unshiu Marc. Alleviates Glucose and Lipid Metabolism by Regulating the Gut Microbiota and Metabolites

The effects of pectin from Citrus unshiu Marc. on glycolipid metabolism, the morphologies of the pancreas and epididymal fat, the gut microbiota, and the metabolites of short-chain fatty acids (SCFAs) in db/db mice were investigated in this study. The results indicated that pectin reduced the levels of fasting blood glucose, glycated serum protein, triglycerides, total cholesterol, and low-density lipoprotein cholesterol while increasing the levels of high-density lipoprotein cholesterol. Meanwhile, pectin could improve the morphology of islet cells and inhibit the hypertrophy of adipocytes. Additionally, pectin not only regulated the intestinal flora dysbiosis in db/db mice, as shown by the increasing proportion of Firmicutes/Bacteroidetes and the relative abundance of Ligilactobacillus, Lactobacillus, and Limosilactobacillus, but also remedied the metabolic disorder of SCFAs in db/db mice. These results suggest that pectin could promote glucose and lipid metabolism by regulating the intestinal flora with changes in SCFA profile. This study proves that pectin might serve as a new prebiotic agent to prevent the disorder of glycolipid metabolism.

Acute toxicity of tire wear particles and leachate to Daphnia magna

Tire wear particles (TWP) are a new pollutant widely present in the environment, and have been identified as microplastics (MPs), which are receiving increasing attention due to their toxic effects on aquatic organisms. In this study, D. magna was used as test organism, and the leachate from TWP was prepared by hot water extraction for 30 (30-E) and 120 min (120-E). The acute toxic effects of particles and leachate on D. magna were studied under different exposure concentrations. The results showed that zinc and pyrene were the highest detected contaminants in the leachate. The 48 h-LC50 values for particles and leachate were determined to be 56.99, 461.30 (30-E), and 153.00 mg/L (120-E), respectively. Following a 48 h exposure period, the immobilization of D. magna exposed to the particles and their leachate were increased with the concentration increase. The physical damage of the gut was found to be a possible mechanism for particle-induced biotoxicity. The compounds leached from TWP were responsible for the acute toxicity of leachate. Particles usually demonstrated a greater degree of toxicity in comparison to their leachate, especially at environmentally relevant concentrations. Exposure to particles and leachate resulted in the inhibition of swimming speed, swimming acceleration, filtration rate, and ingestion rate in D. magna. Furthermore, thoracic limb activity was observed to be inhibited. The heart rate of D. magna was significantly increased by the presence of particles at a concentration of 200 mg/L and leachate at concentrations of 400 and 800 mg/L (120-E). The observed alterations in behavior and physiological endpoints may be related to oxidative stress and neurotoxicity in the organism. Reduced superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) activities indicated that D. magna may suffer from excessive oxidative stress, whereas the increase of acetylcholinesterase (AChE) activity may serve as a biomarker of susceptibility to evaluate the environmental risks of TWP and corresponding leachates as potential aquatic pollutants.. Therefore, a more comprehensive risk assessment of TWP in the environment is necessary.

Mechanism of the antidiabetic action of Nigella sativa and Thymoquinone: a review

Introduction

Long used in traditional medicine, Nigella sativa (NS; Ranunculaceae) has shown significant efficacy as an adjuvant therapy for diabetes mellitus (DM) management by improving glucose tolerance, decreasing hepatic gluconeogenesis, normalizing blood sugar and lipid imbalance, and stimulating insulin secretion from pancreatic cells. In this review, the pharmacological and pharmacokinetic properties of NS as a herbal diabetes medication are examined in depth, demonstrating how it counteracts oxidative stress and the onset and progression of DM.

Methods

This literature review drew on databases such as Google Scholar and PubMed and various gray literature sources using search terms like the etiology of diabetes, conventional versus herbal therapy, subclinical pharmacology, pharmacokinetics, physiology, behavior, and clinical outcomes.

Results

The efficiency and safety of NS in diabetes, notably its thymoquinone (TQ) rich volatile oil, have drawn great attention from researchers in recent years; the specific therapeutic dose has eluded determination so far. TQ has anti-diabetic, anti-inflammatory, antioxidant, and immunomodulatory properties but has not proved druggable. DM's intimate link with oxidative stress, makes NS therapy relevant since it is a potent antioxidant that energizes the cell's endogenous arsenal of antioxidant enzymes. NS attenuates insulin resistance, enhances insulin signaling, suppresses cyclooxygenase-2, upregulates insulin-like growth factor-1, and prevents endothelial dysfunction in DM.

Conclusion

The interaction of NS with mainstream drugs, gut microbiota, and probiotics opens new possibilities for innovative therapies. Despite its strong potential to treat DM, NS and TQ must be examined in more inclusive clinical studies targeting underrepresented patient populations.

Polysaccharides: The Potential Prebiotics for Metabolic Associated Fatty Liver Disease (MAFLD)

Metabolic (dysfunction) associated fatty liver disease (MAFLD) is recognized as the most prevalent chronic liver disease globally. However, its pathogenesis remains incompletely understood. Recent advancements in the gut-liver axis offer novel insights into the development of MAFLD. Polysaccharides, primarily derived from fungal and algal sources, abundantly exist in the human diet and exert beneficial effects on glycometabolism, lipid metabolism, inflammation, immune modulation, oxidative stress, and the release of MAFLD. Numerous studies have demonstrated that these bioactivities of polysaccharides are associated with their prebiotic properties, including the ability to modulate the gut microbiome profile, maintain gut barrier integrity, regulate metabolites produced by gut microbiota such as lipopolysaccharide (LPS), short-chain fatty acids (SCFAs), and bile acids (BAs), and contribute to intestinal homeostasis. This narrative review aims to present a comprehensive summary of the current understanding of the protective effects of polysaccharides on MAFLD through their interactions with the gut microbiota and its metabolites. Specifically, we highlight the potential molecular mechanisms underlying the prebiotic effects of polysaccharides, which may give new avenues for the prevention and treatment of MAFLD.

Digestion profile, antioxidant, and antidiabetic capacity of Morchella esculenta exopolysaccharide: in vitro, in vivo and microbiota analysis

BACKGROUND

Novel functional polysaccharides from fungi are important nutraceuticals. An exopolysaccharide, Morchella esculenta exopolysaccharide (MEP 2), was extracted and purified from the fermentation liquor of M. esculenta. The aim of this study was to investigate its digestion profile, antioxidant capacity, and effect on the microbiota composition in diabetic mice.

RESULTS

The study found that MEP 2 was stable during in vitro saliva digestion but was partially degraded during gastric digestion. The digest enzymes exerted a negligible effect on the chemical structure of MEP 2. Molecular weight and atomic force microscope (AFM) images suggest that both smaller chains and larger aggregations were produced. Scanning electron microscope (SEM) images reveal that the surface morphology was much altered after intestinal digestion. After digestion, the antioxidant ability increased as revealed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Both MEP 2 and its digested components showed strong α-amylase and moderate α-glucosidase inhibition activity, leading us to further investigate its ability to modulate the diabetic symptoms. The MEP 2 treatment ameliorated the inflammatory cell infiltration and increased the size of pancreas inlets. Serum concentration of HbA1c was significantly reduced. Blood glucose level during the oral glucose tolerance test (OGTT) was also slightly lower. The MEP 2 increased the diversity of the gut microbiota and modulated the abundance of several important bacteria including Alcaligenaceae, Caulobacteraceae, Prevotella, Brevundimonas, Demequina, and several Lachnospiraceae species.

CONCLUSION

It was found that MEP 2 was partially degraded during in vitro digestion. Its potential antidiabetic bioactivity may be associated with its α-amylase inhibition and gut microbiome modulation ability. © 2023 Society of Chemical Industry.

Molecular mechanisms and signaling pathways of black cumin (Nigella sativa) and its active constituent, thymoquinone: a review

BACKGROUND

Nigella sativa and its main bioactive ingredient, thymoquinone, exhibit various pharmacological activities, including neuroprotective, nephroprotective, cardioprotective, gastroprotective, hepatoprotective, and anti-cancer effects. Many studies have been conducted trying to elucidate the molecular signaling pathways that mediate these diverse pharmacological properties of N. sativa and thymoquinone. Accordingly, the goal of this review is to show the effects of N. sativa and thymoquinone on different cell signaling pathways.

METHODS

The online databases Scopus, PubMed and Web of Science were searched to identify relevant articles using a list of related keywords such as Nigella sativa, black cumin, thymoquinone, black seed, signal transduction, cell signaling, antioxidant, Nrf2, NF-κB, PI3K/AKT, apoptosis, JAK/STAT, AMPK, MAPK, etc. Only articles published in the English language until May 2022 were included in the present review article.

RESULTS

Studies indicate that N. sativa and thymoquinone improve antioxidant enzyme activities, effectively scavenges free radicals, and thus protect cells from oxidative stress. They can also regulate responses to oxidative stress and inflammation via Nrf2 and NF-κB pathways. N. sativa and thymoquinone can inhibit cancer cell proliferation through disruption of the PI3K/AKT pathway by upregulating phosphatase and tensin homolog. Thymoquinone can modulate reactive oxygen species levels in tumor cells, arrest the cell cycle in the G2/M phase as well as affect molecular targets including p53, STAT3 and trigger the mitochondrial apoptosis pathway. Thymoquinone, by adjusting AMPK, can regulate cellular metabolism and energy hemostasis. Finally, N. sativa and thymoquinone can elevate brain GABA content, and thus it may ameliorate epilepsy.

CONCLUSIONS

Taken together, the improvement of antioxidant status and prevention of inflammatory process by modulating the Nrf2 and NF-κB signaling and inhibition of cancer cell proliferation through disruption of the PI3K/AKT pathway appear to be the main mechanisms involved in different pharmacological properties of N. sativa and thymoquinone.

Effect of mussel polysaccharide on glucolipid metabolism and intestinal flora in type 2 diabetic mice

BACKGROUND

Type 2 diabetes (T2D) mellitus is a major metabolic disease, and its incidence and lethality have increased significantly in recent years, making it a serious threat to human health. Among numerous previous studies, polysaccharides have been shown to alleviate the adverse effects of T2D, but there are still problems such as insufficient analysis and poor understanding of the mechanisms by which polysaccharides, especially those of marine origin, regulate T2D.

METHODS

In this study, we used multiple allosteric approaches to further investigate the regulatory effects of mussel polysaccharides (MPs) on T2D and gut microbiota disorders in mice by identifying changes in genes, proteins, metabolites and target organs associated with glucolipid metabolism using an animal model of T2D fed with high-fat diets, and to explore the underlying molecular mechanisms.

RESULTS

After MP intervention, serum levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and high-density lipoprotein cholesterol (HDL-C) were up-regulated, and blood glucose and lipid levels were effectively reduced in T2D mice. Activation of signaling molecules related to the upstream and downstream of the insulin PI3K/Akt signaling pathway reduced hepatic insulin resistance. The relative abundance of short-chain fatty acid (SCFA)-producing bacteria (including Akkermansia, Siraeum Eubacterium and Allobaculum) increased and harmful desulfurizing Vibrio decreased. In addition, the levels of SCFAs were increased.

CONCLUSION

These results suggest that MP can increase SCFA levels by altering the abundance of intestinal flora, thereby activating the PI3K/Akt signaling pathway and exerting hypoglycemic effects. © 2023 Society of Chemical Industry.

Effects of highland barley β-glucan on blood glucose and gut microbiota in streptozotocin-induced, diabetic, C57BL/6 mice on a high-fat diet

OBJECTIVES

This study aimed to investigate the hypoglycemic effect of highland barley β-glucan (HBG) on mice with type 2 diabetes (T2D), and determine whether the hypoglycemic effects are related to modulations of the gut microbiota.

METHODS

T2D was induced with a high-fat diet and streptozotocin in the mice. HBG was orally administered to mice with T2D for 4 wk, and biochemical indices were analyzed in the serum and liver. Fecal samples were collected and analyzed with high-throughput 16S ribosomal RNA sequencing.

RESULTS

Intake of HBG for 4 wk suppressed the body weight, as well as liver and heart indices, and regulated the levels of fasting blood glucose, serum insulin, blood lipid, oxidative damage, and inflammatory reaction in mice with T2D. Furthermore, HBG reversed the gut microbiota dysbiosis in mice with T2D by increasing the abundance of Lachnospiraceae_UCG-006, Streptococcaceae, and Eggerthellaceae, and by decreasing the abundance of Parasutterella.

CONCLUSIONS

Our findings indicate that the antidiabetic abilities of HBG might be related to the improvement of gut microbiota imbalance.

Oligosaccharides isolated from Rehmannia glutinosa protect LPS-induced intestinal inflammation and barrier injury in mice

Objectives

We investigated the protective effect of Rehmannia glutinosa oligosaccharides (RGO) on lipopolysaccharide (LPS)-induced intestinal inflammation and barrier injury among mice.

Methods

RGO is prepared from fresh rehmannia glutinosa by water extraction, active carbon decolorization, ion exchange resin impurity removal, macroporous adsorption resin purification, and decompression drying. LPS could establish the model for intestinal inflammation and barrier injury in mice. Three different doses of RGO were administered for three consecutive weeks. Then the weight, feces, and health status of the mice were recorded. After sacrificing the mice, their colon length and immune organ index were determined. The morphological changes of the ileum and colon were observed using Hematoxylin-eosin (H&E) staining, followed by measuring the villus length and recess depth. RT-qPCR was utilized to detect the relative mRNA expression of intestinal zonula occludens-1 (ZO-1) and occludin. The expression of inflammatory factors and oxidation markers within ileum and colon tissues and the digestive enzyme activities in the ileum contents were detected using ELISA. The content of short-chain fatty acids (SCFAs) in the colon was determined with GC. The gut microbial composition and diversity changes were determined with 16S-rRNA high-throughput sequencing. The association between intestinal microorganisms and SCFAs, occludins, digestive enzymes, inflammatory factor contents, and antioxidant indexes was also analyzed.

Results

RGO significantly increased the weight, pancreatic index, thymus index, and colon length of mice compared with the model group. Moreover, it also improved the intestinal tissue structure and increased the expression of intestinal barrier-related junction proteins ZO-1 and Occludin. The contents of IL-6, IL-17, IL-1β, and TNF-α in the intestinal tissues of mice were significantly reduced. Additionally, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were elevated. In contrast, the malondialdehyde (MDA) content decreased. Trypsin and pancreatic lipase activities in the ileum enhanced, and the SCFA contents such as acetic acid, propionic acid, and butyric acid in the colon increased. The study on intestinal flora revealed that RGO could enhance the abundance of intestinal flora and improve the flora structure. After RGO intervention, the relative abundance of Firmicutes, Lactobacillus, and Akkermania bacteria in the intestinal tract of mice increased compared with the model group, while that of Actinomycetes decreased. The intestinal microbiota structure changed to the case, with probiotics playing a dominant role. The correlation analysis indicated that Lactobacillus and Ackermann bacteria in the intestinal tract of mice were positively associated with SCFAs, Occludin, ZO-1, pancreatic amylase, SOD, and CAT activities. Moreover, they were negatively correlated with inflammatory factors IL-6, IL-17, IL-1β, and TNF-α.

Conclusions

RGO can decrease LPS-induced intestinal inflammation and intestinal barrier injury in mice and protect their intestinal function. RGO can ameliorate intestinal inflammation and maintain the intestinal barrier by regulating intestinal flora.

Bifidobacterium lactis Probio-M8 ameliorated the symptoms of type 2 diabetes mellitus mice by changing ileum FXR-CYP7A1

The aim of this study was to investigate the effect of Bifidobacterium lactis Probio-M8 on glucolipid metabolism and gut microbiota (GM) composition in type 2 diabetes mellitus (T2DM) mice. The glucolipid metabolic profiles were analyzed. The 16S rRNA gene sequencing was employed to investigate GM. The levels of farnesyl X receptor (FXR) and cytochrome p450 7A1 (CYP7A1) were detected by quantitative polymerase chain reaction and western blot assays. The total bile acids (TBAs), ceramide (CE), glucagon-like peptide-1 (GLP-1), and fibroblast growth factor (FGF)-15 were also detected. The morphological features of liver and pancreas were also analyzed. Compared with the model group, Probio-M8 restored body weight, food intake and water intake, as well as improved hyperglycemia symptoms, serum glucolipid parameters, and the composition of intestinal microbes in T2DM diabetic mice. Moreover, the reduced level of FXR and the increased level of CYP7A1 in T2DM mice were reversed by Probio-M8 treatment. The increased levels of TBA and CE and the reduced levels of GLP-1 and FGF-15 in T2DM mice were altered after Probio-M8 stimulation. Besides, the altered morphology of liver and ileum in T2DM mice was alleviated by Probio-M8 treatment. Taken together, we suggested that the symptoms of T2DM could be ameliorated by Probio-M8 in T2DM mice.

Exopolysaccharide from Lactobacillus rhamnosus ZFM231 alleviates DSS-induced colitis in mice by regulating gut microbiota

BACKGROUND

The exopolysaccharides (EPS) produced by Lactobacillus and other probiotics are associated with many benefits, such as immune regulation, antioxidant properties, antitumor effect, and regulation of intestinal microbe homeostasis. In the present study, the modulatory effect of EPS produced by Lactobacillus rhamnosus ZFM231 on the intestinal flora of mice with inflammatory bowel disease induced by dextran sulfate solution was investigated.

RESULTS

Results indicated that weight loss, colonic length, the disease activity index score and colonic tissue damage in mice were significantly improved by EPS treatment. Compared with the model group, in the EPS-treated group, the diversity of and the composition of gut microbiota at both phylum and genus levels were found to recover to the levels of normal group, indicating the effective modulation on gut microbiota by EPS; short-chain fatty acids, including acetic acid, propionic acid and butyric acid produced by intestinal microbial metabolism, increased significantly; the level of anti-inflammatory factor transforning growth factor-β significantly increased and the level of pro-inflammatory factor tumor necrosis factor-α significantly decreased in the colonic cells of EPS-treated mice.

CONCLUSION

It is clear that EPS produced by L. rhamnosus ZFM231 could find application in functional foods with the property of anti-ulcerative colitis. The experimental results provide new insights into the probiotic effect of EPS. © 2022 Society of Chemical Industry.

Potential health benefits of Nigella sativa on diabetes mellitus and its complications: A review from laboratory studies to clinical trials

This review aims to gather and summarize up-to-date information on the potential health benefits of Nigella sativa (NS) on diabetes mellitus (DM) and its complications from different animal models, clinical trials and in vitro studies. DM is one of the most prevalent metabolic disorders resulting from chronic hyperglycaemia due to problems in insulin secretion, insulin action or both. It affects people regardless of age, gender and race. The main consequence of DM development is the metabolic dysregulation of glucose homeostasis. Current treatments for DM include pharmacological therapy, insulin and diabetic therapy targeting β cells. Some of these therapeutic approaches are promising; however, their safety and effectiveness remain elusive. Since ancient times, medicinal plants have been used and proven effective against diseases. These plants are believed to be effective and benefit physiological and pathological processes, as they can be used to prevent, reduce or treat multiple diseases. Nigella sativa Linn. is an annual indigenous herbaceous plant belonging to Ranunculaceae, the buttercup family. NS exhibits multifactorial activities; it could ameliorate oxidative, inflammatory, apoptotic and insulinotropic effects and inhibit carbohydrate digestive enzymes. Thus, this review demonstrates the therapeutic potential of NS that could be used as a complement or adjuvant for the management of DM and its complications. However, future research should be able to replicate and fill in the gaps of the study conducted to introduce NS safely to patients with DM.

Antidiabetic Effect of Millet Bran Polysaccharides Partially Mediated via Changes in Gut Microbiome

Diabetes is a type of metabolic disease associated with changes in the intestinal flora. In this study, the regulatory effect of millet bran on intestinal microbiota in a model of type 2 diabetes (T2DM) was investigated in an effort to develop new approaches to prevent and treat diabetes and its complications in patients. The effect of purified millet bran polysaccharide (MBP) with three different intragastric doses (400 mg/kg, 200 mg/kg, and 100 mg/kg) combined with a high-fat diet was determined in a streptozotocin (STZ)-induced model of T2DM. By analyzing the changes in indicators, weight, fasting blood sugar, and other bio-physiological parameters, the changes in gut microbiota were analyzed via high-throughput sequencing to establish the effect of MBP on the intestinal flora. The results showed that MBP alleviated symptoms of high-fat diet-induced T2DM. A high dosage of MBP enhanced the hypoglycemic effects compared with low and medium dosages. During gavage, the fasting blood glucose (FBG) levels of rats in the MBP group were significantly reduced (p < 0.05). The glucose tolerance of rats in the MBP group was significantly improved (p < 0.05). In diabetic mice, MBP significantly increased the activities of CAT, SOD, and GSH-Px. The inflammatory symptoms of liver cells and islet cells in the MBP group were alleviated, and the anti-inflammatory effect was partially correlated with the dose of MBP. After 4 weeks of treatment with MBP, the indices of blood lipid in the MBP group were significantly improved compared with those of the DM group (p < 0.05). Treatment with MBP (400 mg/kg) increases the levels of beneficial bacteria and decreases harmful bacteria in the intestinal tract of rats, thus altering the intestinal microbial community and antidiabetic effect on mice with T2DM by modulating gut microbiota. The findings suggest that MBP is a potential pharmaceutical supplement for preventing and treating diabetes.

Nigella sativa L. and Its Active Compound Thymoquinone in the Clinical Management of Diabetes: A Systematic Review

Despite existing conventional hypoglycemic drugs to manage diabetes, their non-availability and cost in low-income countries coupled with the associated side effects remain a major concern. Consequently, exploring for alternative treatments to manage diabetes has been a continuous priority. Nigella sativa L. (NS) (Family: Ranunculaceae) is regarded as a valuable traditional remedy in diabetes management and extensively studied for its biological properties. This systematic review provides a comprehensive and critical analysis of clinical studies on the efficacy, safety, and mechanism of action of NS and its compound thymoquinone (TQ) in diabetes management. The main scientific databases which were scrutinised were Scopus, PubMed, Google Scholar, and Web of Science. Data search was conducted from inception to January 2022. A total of 17 clinical studies were obtained; 16 studies on Nigella sativa L. and 1 study on its compound TQ. N. sativa was found to be highly potent in terms of its hypoglycemic activity when compared to placebo based on improvement in parameters including fasting blood glucose (FBG), postprandial blood glucose (PPBG), Hemoglobin A1C (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), and homeostatic model assessment for assessment of beta-cell functionality (HOMA-β). The compound TQ in combination with a daily dose of metformin demonstrated a greater reduction in the levels of HbA1c and blood glucose compared to metformin alone. The bioavailability of TQ can be enhanced by using nanoparticulate drug delivery systems. Considering the findings of the clinical studies along with negligible adverse effects, NS has strong potential application in bioproduct development for the management of diabetes. Further investigations should explore the detailed mechanism of actions by which TQ exerts its therapeutic antidiabetic effects to provide more insights into its clinical use in the management of diabetes.

Evaluation of fluorene-caused ecotoxicological responses and the mechanism underlying its toxicity in Eisenia fetida: Multi-level analysis of biological organization

Fluorene is an important toxic chemical that exists ubiquitously in the environment, and it has also been suggested to exert potential deleterious effects on soil invertebrates. However, knowledge about the toxic effects of fluorene and its underlying mechanisms of the effects on key soil organism earthworms remains limited. From this view point, this study was undertaken to explore the potential effects of fluorene and its underlying mechanisms in Eisenia fetida at the level of experimental animals, tissue, cell, and molecule. It was concluded that fluorene exerted lethal activity to adult E. fetida on day 14 with the LC₅₀ determined to be 88.61 mg/kg. Fluorene-induced ROS caused oxidative stress in E. fetida, resulting in DNA damage, protein carbonylation, and lipid peroxidation. Moreover, changed antioxidative enzymatic activities, non-enzymatic antioxidative activities, and total antioxidative capacity in E. fetida by fluorene stress are associated with antioxidative and protective effects. High-dose fluorene (> 2.5 mg/kg) exposure significantly caused histopathological lesions including the microstructure of body wall, intestine, and seminal vesicle of earthworms. Also, the reproductive system of E. fetida was clearly disrupted by fluorene stress, leading to poor reproduction ability (decreased cocoon and juvenile production) in earthworms. It is found that E. fetida growth was significantly inhibited when treated with high-dose fluorene, thereby causing normal growth disorders. Additionally, fluorene stress triggered the abnormal mRNA expression related to oxidative stress (e.g., metallothionein and heat shock protein 70), growth (translationally controlled tumour protein), reproduction (annetocin precursor) in E. fetida. Together, both high-dose and long-term exposure elicited more severe poisoning effects on earthworms using the Integrated Biological Response (IBR) index, and E. fetida coelomocyte DNA was the most negatively affected by fluorene stress. This study comprehensively evaluated fluorene-induced toxicity in E. fetida, and its underlying molecular mechanisms mediating the toxic responses have been elucidated. These findings provide valuable data for assessing potential ecological risks posed by fluorene-contaminated soil.

Metformin alleviates long-term high-fructose diet-induced skeletal muscle insulin resistance in rats by regulating purine nucleotide cycle

Nutrient excess caused by excessive fructose intake can lead to insulin resistance and dyslipidemia, which further causes the development of metabolic syndrome. Metformin is a well-known AMPK activator widely used for the treatment of metabolic syndrome, while the mechanism of AMPK activation remains unclear. The present study aimed to investigate the pharmacological effects of metformin on fructose-induced insulin resistance rat, and the potential mechanism underlying AMPK activation in skeletal muscle tissue. Results indicated that metformin significantly ameliorated features of insulin resistance, including body weight, Lee's index, hyperinsulinemia, dyslipidemia, insulin intolerance and pancreatic damage. Moreover, treatment with metformin attenuated the inflammatory response in serum and enhanced the antioxidant capacity in skeletal muscle tissue. The therapeutic effects of metformin on fructose-induced insulin resistance may be related to the activation of AMPK to regulate Nrf2 pathway and mitochondrial abnormality. Additionally, metformin suppressed the expression of adenosine monophosphate deaminase 1 (AMPD1) and up-regulated the expression of adenylosuccinate synthetase (ADSS) in the purine nucleotide cycle (PNC), which facilitated the increase of AMP level and the ratio of AMP/ATP. Therefore, we proposed a novel mechanism that metformin activated AMPK via increasing AMP by regulating the expression of AMPD1 and ADSS in PNC pathway.

Therapeutic potential of non-starch polysaccharides on type 2 diabetes: from hypoglycemic mechanism to clinical trials

Non-starch polysaccharides (NSPs) have been reported to exert therapeutic potential on managing type 2 diabetes mellitus (T2DM). Various mechanisms have been proposed; however, several studies have not considered the correlations between the anti-T2DM activity of NSPs and their molecular structure. Moreover, the current understanding of the role of NSPs in T2DM treatment is mainly based on in vitro and in vivo data, and more human clinical trials are required to verify the actual efficacy in treating T2DM. The related anti-T2DM mechanisms of NSPs, including regulating insulin action, promoting glucose metabolism and regulating postprandial blood glucose level, anti-inflammatory and regulating gut microbiota (GM), are reviewed. The structure-function relationships are summarized, and the relationships between NSPs structure and anti-T2DM activity from clinical trials are highlighted. The development of anti-T2DM medication or dietary supplements of NSPs could be promoted with an in-depth understanding of the multiple regulatory effects in the treatment/intervention of T2DM.

Effects of two triterpenoids from Nigella sativa seeds on insulin resistance of 3T3-L1 adipocytes

Insulin resistance (IR) is a physiological abnormality that occurs when insulin fails to activate the signal transduction pathway in target organs. It was found that supplementation of Nigella sativa seeds with oral antidiabetic medicines helps improve blood glucose control by enhanced β cells activity and alleviation of IR. However, the activities and related mechanisms of phytochemicals from N. sativa seeds have not been thoroughly explored. In this study, the effects of two triterpenoids, 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-28-O-[α-L-rhamnose-(1→4)-β-D-glucopyranose-L-(1→6)-β-D-glucopyranose]-hederagenin (Hxrarg) and 3-O-[β-D-xylopyranose-(1→3)-α-L-rhamnose-(1→2)-α-L-arabinose]-hederagenin (Hxra), on IR were studied by 3T3-L1 adipocytes model. The results demonstrated that Hxrarg and Hxra inhibited maturation of 3T3-L1 preadipocytes, dramatically stimulated glucose uptake of IR-3T3-L1 adipocytes, promoted transcription of IRS, AKT, PI-3K, and GLUT4 mRNA. Western Blot results suggested that Hxrarg and Hxra were able to markedly up-regulate expression of p-IRS, p-AKT, PI-3K, and GLUT4 proteins. These findings could provide a basic foundation for the continued development and application of N. sativa in medicine and functional foods.

Bacillus sp. DU-106 ameliorates type 2 diabetes by modulating gut microbiota in high-fat-fed and streptozotocin-induced mice

AIMS

Type 2 diabetes mellitus (T2D) is a chronic disease that manifests as endocrine and metabolic disorders that seriously threatening public health. This study aimed to investigate the effects of Bacillus sp. DU-106 on anti-diabetic effects and gut microbiota in C57BL/6J mice fed a high-fat diet and streptozotocin-induced T2D.

METHODS AND RESULTS

Bacillus sp. DU-106 was administered to model mice for eight consecutive weeks. Oral administration of Bacillus sp. DU-106 decreased food and water intake and alleviated body weight loss. Moreover, Bacillus sp. DU-106 imparted several health benefits to mice, including balanced blood glucose, alleviation of insulin resistance in T2D mice, and an improvement in lipid metabolism. Furthermore, Bacillus sp. DU-106 protected against liver and pancreatic impairment. Additionally, Bacillus sp. DU-106 treatment reshaped intestinal flora by enhancing gut microbial diversity and enriching the abundance of certain functional bacteria.

CONCLUSION

Collectively, these findings suggest that Bacillus sp. DU-106 can ameliorate T2D by regulating the gut microbiota.

SIGNIFICANCE AND IMPACT OF STUDY

Therefore, a novel probiotic, Bacillus sp. DU-106 may be a promising therapeutic agent for improving and alleviating T2D in mice.

Chemical constituents from the seeds of Nigella glandulifera and their hypoglycemic activities

The seeds of Nigella glandulifera Freyn et Sint. are traditional Uygur medicine used for the treatment of diabetes. However, the active anti-diabetic constituents in the seeds of N. glandulifera remain unclear. In the present study, a new delabellane-type diterpene, 8-denicotinoylnigellamine A1 (1), and a new acyclic sesquiterpene, 2,6,10-trimethyl-6,7,12-trihydroxy-dodec-2-ene (3), together with eight known compounds including alkaloids (2 and 7), triterpenoid saponins (4–6), and phenolic compounds (8–10), were isolated from the seeds of N. glandulifera. Their structures were determined by extensive spectroscopic analyses and quantum chemical calculations. We evaluated the potential protective effects of the isolated compounds on an insulin resistant HepG2 (IR-HepG2) cell model. The results showed that compounds 2, 4–8, and 10 could promote the consumption of glucose in IR-HepG2 cells. Those compounds might be responsible for the anti-diabetic effects of the seeds of N. glandulifera.

The seed of Nigella glandulifera Freyn et Sint. is a traditional Uygur medicine used for the treatment of diabetes.

The Immunomodulatory Effects of Active Ingredients From Nigella sativa in RAW264.7 Cells Through NF-κB/MAPK Signaling Pathways

Nigella sativa is a valuable herb for its functional compositions in both food and medication. N. sativa seeds can enhance immunity, anti-inflammation and analgesia and hypoglycemia, but most of the related researches are related to volatile oil and extracts, and the activity and mechanism of compounds is not clear. In this study, Ethyl-α-D-galactopyranoside (EG), Methyl-α-D-glucoside (MG), 3-O-[β-D-xylopyranose-(1 → 3)-α-L-rhamnose-(1 → 2)-α-L-arabinose]-28-O-[α-L-rhamnose-(1 → 4)-β-D-glucopyranose-L-(1 → 6)-β-D-glucopyranose]-hederagenin (HXRARG) and 3-O-[β-D-xylopyranose-(1 → 3)-α-L-rhamnose-(1 → 2)-α-L-arabinose]-hederagenin (HXRA) were isolated and identified from N. sativa seeds. In addition, four compounds could activate NF-κB pathway by promoting the expression of phosphorylation of P65 and IκBα, promoting the phosphorylation of JNK, Erk and P38 to activate MAPK signaling pathway, enhancing the proliferation and phagocytic activity of RAW264.7 cells, and promoting the release of NO, TNF-α and IL-6 on RAW264.7 cell in vitro. The results showed that N. sativa can be used as dietary supplement to enhance immune.

Functional yogurt fermented by two-probiotics regulates blood lipid and weight in a high-fat diet mouse model

We investigated the blood lipid regulation effects and mechanism of a functional Natto yogurt in a high-fat diet-induced hyperlipidemia mouse model. Natto yogurt was characteristically fermented by Bacillus natto and Lactobacillus plantarum with milk-soy dual protein as substrates. After 5 weeks of Natto yogurt consumption, the body weight, fat, and liver weight of mice were significantly improved, while serum levels of TG, TC, LDL, ALT, TBIL, and TBA were reduced. Natto yogurt significantly decreased the area of liver fat infiltration and the number of lipid droplets. In mechanism, we found that Natto yogurt can inhibit fatty acid synthesis and enhance fatty acid catabolism by regulating the expression of PPARα, PPARγ, CD36 and FAS in the liver. Moreover, Natto yogurt increased the ratio of Bacteroidetes to Firmicutes in the intestine. These results provide a possibility for Natto yogurt as a dual protein functional food to prevent and treat hyperlipidemia and obesity. PRACTICAL APPLICATIONS: Traditional-fermented yogurt promotes nutritional absorption and reduces blood pressure and fat, while Bacillus natto and its fermented food have been proved to play a significant role in improving cardiovascular and cerebrovascular diseases and obesity. Therefore, we developed a new dual protein functional yogurt (Natto yogurt) fermented by B. natto and Lactobacillus plantarum with milk and soy as substrates. We found that Natto yogurt could notably regulate blood lipid by inhibiting the synthesis of fatty acids, accelerating the catabolism of fatty acids, reducing liver damage, and increasing the abundance of beneficial intestinal microorganisms. This study suggested that Natto yogurt could improve hyperlipidemia and obesity as a safe, effective, and healthy functional food.

The Ameliorating Effects of Apple Polyphenol Extract on High-Fat-Diet-Induced Hepatic Steatosis Are SIRT1-Dependent: Evidence from Hepatic-Specific SIRT1 Heterozygous Mutant C57BL/6 Mice

Apple polyphenol extract (APE) has been reported to possess protective effects against hepatic steatosis. To explore whether APE-induced alleviation of hepatic steatosis is SIRT1-dependent, the present study was carried out using wild-type and hepatic SIRT1 heterozygous mutant (Sirt1^+/-) C57BL/6 mice. On consideration of the sex disparity related to hepatic steatosis morbidity, both male and female mice were included in the study. Six to eight week old mice were fed a high-fat diet (HFD) and randomly assigned to one of the following groups: (1) wild-type mice (wt+HFD), (2) Sirt1^+/- mice (Sirt1^+/-+HFD), and (3) Sirt1^+/- mice with 500 mg/(kg·bw·d) APE intragastric administration (Sirt1^+/-+HAP). HFD-induced weight gain and triglyceride accumulation was more prominent in Sirt1^+/- mice in comparison to wild-type mice. Following APE treatment, these effects were significantly reduced along with the alleviation of hepatic steatosis via upregulated expression of SIRT1 at the protein and mRNA levels in both male and female mice. However, APE differentially regulated the genes related to lipid metabolism (Lkb1, Ampk, Hsl, Srebp-1c, Abcg1, and Cd36) in a sex-specific manner. Moreover, APE treatment altered gut microbiota composition, with an increased relative abundance of Akkermansia and a decreased Firmicutes/Bacterodetes ratio. Thus, our study provided new evidence supporting our hypothesis that APE-induced alleviation of hepatic steatosis is SIRT1-dependent.

Effect of Nigella Sativa Oil on Oxidative Stress, Inflammatory, and Glycemic Control Indices in Diabetic Hemodialysis Patients: A Randomized Double-Blind, Controlled Trial

Background and Aims

Diabetes is a leading cause of renal failure. High levels of oxidative stress and inflammation in patients with renal diabetes lead to various disorders and mortality. This study was performed to determine the effect of Nigella sativa (NS) supplementation on superoxide dismutase (SOD), malondialdehyde (MDA), total antioxidant capacity (TAC), high-sensitivity C-reactive protein (hs-CRP), glycosylated hemoglobin (HbA1c), fasting blood sugar (FBS), and insulin (INS) in patients with diabetes mellitus undergoing hemodialysis (HD).

Methods

In this randomized, double-blind, placebo-controlled clinical trial, a total of 46 diabetic HD patients were randomly divided into NS (n = 23) and placebo (n = 23) groups. NS group received 2 g/day of NS oil, and the placebo group received paraffin oil for 12 weeks. Serum levels of SOD, MDA, TAC, hs-CRP, HbA1C, FBS, and INS were measured before and after the study.

Results

Compared to baseline values, SOD, TAC, and INS levels increased, whereas MDA, hs-CRP, HbA1c, and FBS significantly decreased. After adjusting for covariates using the ANCOVA test, changes in the concentrations of SOD (p = .040), MDA (p = .025), TAC (p=<.001), hs-CRP (p = .017), HbA1c (p = .014), and FBS (p = .027) were statistically significant compared to the placebo group. Intergroup changes in INS were not significant. Additionally, there were no notable side effects during the research.

Conclusions

This study found that NS supplementation significantly enhanced the levels of SOD, MDA, TAC, hs-CRP, HbA1c, and FBS in diabetic HD patients.

Targeting Gut Microbiota With Natural Polysaccharides: Effective Interventions Against High-Fat Diet-Induced Metabolic Diseases

Unhealthy diet, in particular high-fat diet (HFD) intake, can cause the development of several metabolic disorders, including obesity, hyperlipidemia, type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome (MetS). These popular metabolic diseases reduce the quality of life, and induce premature death worldwide. Evidence is accumulating that the gut microbiota is inextricably associated with HFD-induced metabolic disorders, and dietary intervention of gut microbiota is an effective therapeutic strategy for these metabolic dysfunctions. Polysaccharides are polymeric carbohydrate macromolecules and sources of fermentable dietary fiber that exhibit biological activities in the prevention and treatment of HFD-induced metabolic diseases. Of note, natural polysaccharides are among the most potent modulators of the gut microbiota composition. However, the prebiotics-like effects of polysaccharides in treating HFD-induced metabolic diseases remain elusive. In this review, we introduce the critical role of gut microbiota human health and HFD-induced metabolic disorders. Importantly, we review current knowledge about the role of natural polysaccharides in improving HFD-induced metabolic diseases by regulating gut microbiota.

Fucoidan ameliorates glucose metabolism by the improvement of intestinal barrier and inflammatory damage in type 2 diabetic rats

It has been reported that fucoidan possesses anti-diabetic activities by inhibiting α-glucosidase activity, improving β-cell dysfunction, and enhancing insulin sensitivity. However, as a macromolecular carbohydrate, fucoidan is rarely absorbed and indigestible in gastrointestinal tract. The study aimed to explore whether the fucoidan can regulate glucose metabolism by improving intestinal barrier and inflammation in type 2 diabetes mellitus (T2DM) rats. A high-fat diet combined with streptozotocin was used to induce T2DM rats. Different doses of fucoidan (50, 100 and 200 mg/kg) were administered respectively by lavage to T2DM rats for 8 weeks and saline was given to controls. The results showed that in addition to hyperglycemia and hyperlipidemia, T2DM rats were also characterized by increased intestinal permeability and proinflammatory cytokines. Notably, fucoidan reduced fasting blood glucose and insulin resistance index along with alleviated the accumulation of proinflammatory cytokines in T2DM rats. Furthermore, fucoidan repaired the intestinal barrier function, which was accompanied by the up-regulation of tight junction proteins and the improvement of intestinal inflammation via inhibiting TLR4/NF-κB signaling. Meanwhile, fucoidan also mitigated the liver damage, and alleviated insulin resistance by activating PI3K/AKT signaling. Collectively, these findings supported the potential of fucoidan to be used as a functional ingredient to prevent T2DM.

Modulatory effects of polysaccharides from plants, marine algae and edible mushrooms on gut microbiota and related health benefits: A review

Naturally occurring carbohydrate polymers containing non-starch polysaccharides (NPs) are a class of biomacromolecules isolated from plants, marine algae, and edible mushrooms, and their biological activities has shown potential uses in the prevention and treatment of human diseases. Importantly, NPs serve as prebiotics to provide health benefits to the host through stimulating the proliferation of beneficial gut microbiota (GM) and enhancing the production of short-chain fatty acids (SCFAs). The composition and diversity of GM play a critical role in regulating host health and have been extensively studied in recent years. In this review, the extraction, isolation, purification, and structural characterization of NPs derived from plants, marine algae, and edible mushrooms are outlined. Importantly, the degradation and metabolism of these NPs in the intestinal tract, the effects of NPs on the microbial community and SCFAs generation, and the beneficial effects of NPs on host health by modulating GM are systematically highlighted. Overall, we hope that this review can provide some theoretical references and a new perspective for applications of NPs as prebiotics in functional food and drug development.

The Effect of Flammulina velutipes Polysaccharide on Immunization Analyzed by Intestinal Flora and Proteomics

Proteomics and intestinal flora were used to determine the mechanism of immune modulatory effects of Flammulina velutipes polysaccharide on immunosuppressed mice. The results showed that compared with the model group, F. velutipes polysaccharide could increase thymus and spleen indices and improve thymus tissue structure in mice; IL-2 and IL-4 contents were significantly increased and IL-6 and TNF-α contents were significantly decreased; serum acid phosphatase (ACP), lactate dehydrogenase (LDH) and total antioxidant capacity (T-AOC) activities were increased (P < 0.05); in the liver, superoxide dismutase (SOD) and catalase (CAT) activities were increased (P < 0.001), while malondialdehyde (MDA) content was decreased (P < 0.001). Proteomics discovered that F. velutipes polysaccharides may exert immune modulatory effects by participating in signaling pathways such as immune diseases, transport and catabolism, phagosomes and influenza A, regulating the immune-related proteins Transferrin receptor protein 1 (TFRC) and Radical S-adenosyl methionine domain-containing protein 2 (RSAD2), etc. Gut microbial studies showed that F. velutipes polysaccharides could increase the abundance of intestinal flora and improve the flora structure. Compared to the model group, the content of short-chain fatty acids (SCFAs) and the relative abundance of SCFA-producers Bacteroides and Alloprevotella were increased in the F. velutipes polysaccharide administration group, while Lachnospiraceae_NK4A136_group and f_Lachnospiraceae_Unclassified decreased in relative abundance. Thus, F. velutipes polysaccharide may play an immunomodulatory role by regulating the intestinal environment and improving the balance of flora.

Effects of Polygonatum sibiricum saponin on hyperglycemia, gut microbiota composition and metabolic profiles in type 2 diabetes mice

Diabetes is a global disease that endangers human health. As reported, saponins are effective bioactive compounds for treating type 2 diabetes mellitus (T2DM) and have nontoxic side effects. This study aimed to examine the hypoglycemic effects of Polygonatum sibiricum saponin (PSS) on T2DM mice. We found that PSS could significantly decrease the levels of insulin secretion and fasting blood glucose (FBG) in T2DM mice. And the level of triacylglycerol (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the blood was decreased. In contrast, the content of high-density lipoprotein cholesterol (HDL-C) was increased. 16S rDNA sequencing was used to evaluate the changes in the gut microbiota of T2DM mice, and metabolites were analyzed by metabolomic profiling. The results showed that PSS could decrease the abundance of Firmicutes in T2DM mice, increase the abundance of Bacteroidetes. It also increased the abundance of some bacterial genera (Lactobacillus, Lachnospiraceae_NK4A136_group and Intestinimonas). The phenotypes of the gut microbiome also changed accordingly. Metabolomics analysis showed that carbohydrate metabolism and amino acid metabolisms, such as L-alanine and L-glutamic acid, were greatly affected by PSS. In addition, the levels of inositol and chlorogenic acid in metabolites also increased significantly under PSS intervention. In general, PSS could exert its hypoglycemic effect, regulate the gut microbiota and affect the metabolism of T2DM mice.

Study on the Effects of Chinese Materia Medica Processing on the Hypoglycemic Activity and Chemical Composition of Anemarrhenae Rhizoma

PURPOSE

To compare the hypoglycemic effects of different extracts of Anemarrhenae Rhizoma (AR) before and after being stir-baked with salt water on the diabetic mice and to detect the contents of 8 components in the corresponding active parts simultaneously using the UPLC-MS method, in order to screen the better extracts for diabetes and to clear the material basis for enhancing hypoglycemic activity of Anemarrhenae Rhizoma stir-baked with salt water (SAR).

METHODS

Taking spontaneous type II diabetic db/db mice as models and fasting blood glucose (FBG), oral glucose tolerance test (OGTT), glycated hemoglobin or glycosylated hemoglobin (HbAlc), serum resistin (RESISTEIN), fasting insulin (FINS), superoxide dismutase (SOD), malondialdehyde (MDA), and nitric oxide (NO) as indicators, the hypoglycemic effects of different active parts of Anemarrhenae Rhizoma were evaluated. The chromatographic separation was performed on a Waters BEH C18 (2.1 mm × 50 mm, 1.7 μm) column using acetonitrile (B) and 0.1% formic acid in water (A) as mobile phases, and the flow rate was 0.3 ml/min. The column temperature was set as 28°C, and the injection volume was 10 μL. A mass spectrometer was connected to the UPLC system via an electrospray ionization (ESI) interface. Full-scan data acquisition was performed in the negative ion mode.

RESULT

In the study of pharmacodynamics, the hypoglycemic effect of Anemarrhenae Rhizoma stir-baked with salt water is better than that of Anemarrhenae Rhizoma and the hypoglycemic effect of ethanol extract of Anemarrhenae Rhizoma is more remarkable than that of the decoction. The measured components all have a good linear relationship within their respective linear ranges (r ≥ 0.9990); the average recovery rates are 98.86%-100.69%, RSD <2.90%. Compared with the raw Anemarrhenae Rhizoma, the contents of Timosaponin AIII, Timosaponin BII, Timosaponin BIII, Anemarrhenasaponin I, Anemarrhenasaponin Ia, and Mangiferin of Anemarrhenae Rhizoma stir-baked with salt water are all higher, the changes of Timosaponin AI and Anemarrhenasaponin AII are not obvious, and all the contents of chemical composition in the ethanol extract of Anemarrhenae Rhizoma and Anemarrhenae Rhizoma stir-baked with salt water were obviously higher compared with the water decoction.

CONCLUSION

The processing method, stir-baking with salt water, can increase the contents of active compositions in Anemarrhenae Rhizoma and strengthen the hypoglycemic effect. The ethanol extract of Anemarrhenae Rhizoma stir-baked with salt water is the better active site.

Kudzu Resistant Starch: An Effective Regulator of Type 2 Diabetes Mellitus

Kudzu is a traditional medicinal dietary supplement, and recent research has shown its significant benefits in the prevention/treatment of type 2 diabetes mellitus (T2DM). Starch is one of the main substances in Kudzu that contribute decisively to the treatment of T2DM. However, the underlying mechanism of the hypoglycemic activity is not clear. In this study, the effect of Kudzu resistant starch supplementation on the insulin resistance, gut physical barrier, and gut microbiota was investigated in T2DM mice. The result showed that Kudzu resistant starch could significantly decrease the value of fasting blood glucose and the levels of total cholesterol, total triglyceride, and high-density lipoprotein, as well as low-density lipoprotein, in the blood of T2DM mice. The insulin signaling sensitivity in liver tissue was analyzed; the result indicated that intake of different doses of Kudzu resistant starch can help restore the expression of IRS-1, p-PI3K, p-Akt, and Glut4 and thus enhance the efficiency of insulin synthesis. Furthermore, the intestinal microorganism changes before and after ingestion of Kudzu resistant starch were also analyzed; the result revealed that supplementation of KRS helps to alleviate and improve the dysbiosis of the gut microbiota caused by T2DM. These results validated that Kudzu resistant starch could improve the glucose sensitivity of T2DM mice by modulating IRS-1/PI3K/AKT/Glut4 signaling transduction. Kudzu resistant starch can be used as a promising prebiotic, and it also has beneficial effects on the gut microbiota structure of T2DM mice.

Salmon peptides limit obesity-associated metabolic disorders by modulating a gut-liver axis in vitamin D-deficient mice

OBJECTIVE

This study investigated the effects of a low-dose salmon peptide fraction (SPF) and vitamin D₃ (VitD₃ ) in obese and VitD₃ -deficient mice at risk of metabolic syndrome (MetS).

METHODS

Obese and VitD₃ -deficient low-density lipoprotein receptor (LDLr)^-/- /apolipoprotein B100 (ApoB)^100/100 mice were treated with high-fat high-sucrose diets, with 25% of dietary proteins replaced by SPF or a nonfish protein mix (MP). The SPF and MP groups received a VitD₃ -deficient diet or a supplementation of 15,000 IU of VitD₃ per kilogram of diet. Glucose homeostasis, atherosclerosis, nonalcoholic fatty liver disease, and gut health were assessed.

RESULTS

VitD₃ supplementation increased plasma 25-hydroxyvitamin D to optimal status whereas the VitD₃ -deficient diet maintained moderate deficiency. SPF-treated groups spent more energy and accumulated less visceral fat in association with an improved adipokine profile. SPF lowered homeostatic model assessment of insulin resistance compared with MP, suggesting that SPF can improve insulin sensitivity. SPF alone blunted hepatic and colonic inflammation, whereas VitD₃ supplementation attenuated ileal inflammation. These effects were associated with changes in gut microbiota such as increased Mogibacterium and Muribaculaceae.

CONCLUSIONS

SPF treatment improves MetS by modulating hepatic and gut inflammation along with gut microbiota, suggesting that SPF operates through a gut-liver axis. VitD₃ supplementation has limited influence on MetS in this model.

Yellow Wine Polyphenolic Compound Protects Against Doxorubicin-Induced Cardiotoxicity by Modulating the Composition and Metabolic Function of the Gut Microbiota

BACKGROUND

Dietary polyphenols help to prevent cardiovascular diseases, and interactions between polyphenols and gut microbiota are known to exist. In this study, we speculated that gut microbiota-mediated metabolite regulation might contribute to the anticardiotoxic effects of yellow wine polyphenolic compound (YWPC) in doxorubicin (DOX)-treated rats.

METHODS

16S-rDNA sequencing was performed to analyze the effects of YWPC on the gut microbiota in DOX-treated rats (n=6). Antibiotics were used to investigate the contribution of the altered microbiome to the role of YWPC (n=6). Plasma metabolomics were also analyzed by untargeted gas chromatography-mass spectrometry systems.

RESULTS

YWPC ameliorated DOX-mediated cardiotoxicity, as evidenced by increased cardiac and mitochondrial function and reduced levels of inflammation and myocardial apoptosis (P<0.05 for all). The low abundance of Escherichia-Shigella, Dubosiella, and Allobaculum, along with enrichment of Muribaculaceae_unclassified, Ralstonia, and Rikenellaceae_RC9_gut_group in the gut, suggested that YWPC ameliorated DOX-induced microbial dysbiosis. YWPC also influenced the levels of metabolites altered by DOX, resulting in lower arachidonic acid and linoleic acid metabolism and higher tryptophan metabolite levels (P<0.05 for all). Correlational studies indicated that YWPC alleviated DOX-induced inflammation and mitochondrial dysfunction by modulating the gut microbial community and its associated metabolites. Antibiotic treatment exacerbated cardiotoxicity in DOX-treated rats, and its effect on the gut microbiota partly abolished the anticardiotoxic effects of YWPC, suggesting that the microbiota is required for the cardioprotective role of YWPC.

CONCLUSIONS

YWPC protected against DOX-induced cardiotoxicity in a gut microbiota-dependent manner. This supports the use of dietary polyphenols as a therapeutic approach for the treatment of cardiovascular diseases via microbiota regulation.

Discovery of novel glycoside hydrolases from C-glycoside-degrading bacteria using sequence similarity network analysis

C-Glycosides are an important type of natural product with significant bioactivities, and the C-glycosidic bonds of C-glycosides can be cleaved by several intestinal bacteria, as exemplified by the human faeces-derived puerarin-degrading bacterium Dorea strain PUE. However, glycoside hydrolases in these bacteria, which may be involved in the C-glycosidic bond cleavage of C-glycosides, remain largely unknown. In this study, the genomes of the closest phylogenetic neighbours of five puerarin-degrading intestinal bacteria (including Dorea strain PUE) were retrieved, and the protein-coding genes in the genomes were subjected to sequence similarity network (SSN) analysis. Only four clusters of genes were annotated as glycoside hydrolases and observed in the genome of D. longicatena DSM 13814^T (the closest phylogenetic neighbour of Dorea strain PUE); therefore, genes from D. longicatena DSM 13814^T belonging to these clusters were selected to overexpress recombinant proteins (CG1, CG2, CG3, and CG4) in Escherichia coli BL21(DE3). In vitro assays indicated that CG4 efficiently cleaved the O-glycosidic bond of daidzin and showed moderate β-D-glucosidase and β-D-xylosidase activity. CG2 showed weak activity in hydrolyzing daidzin and pNP-β-D-fucopyranoside, while CG3 was identified as a highly selective and efficient α-glycosidase. Interestingly, CG3 and CG4 could be selectively inhibited by daidzein, explaining their different performance in kinetic studies. Molecular docking studies predicted the molecular determinants of CG2, CG3, and CG4 in substrate selectivity and inhibition propensity. The present study identified three novel and distinctive glycoside hydrolases, highlighting the potential of SSN in the discovery of novel enzymes from genomic data.

Nigella sativa: A Dietary Supplement as an Immune-Modulator on the Basis of Bioactive Components

Nutrients can be considered as functional foods, which exert physiological benefits on immune system. The seeds of Nigella sativa, which have many active constituents, are mainly used for medicine, food spice, and nutritional supplements in Egypt. Much attention has been paid to N. sativa seeds for their anticancer, antibacterial, anti-inflammatory, and immune properties. However, their active constituents and mechanisms underlying functions from N. sativa seeds is unclear. Thus, the bioactive constituents with immune regulation in N. sativa seeds were systematically studied. A new compound (3-methoxythymol-6-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside 1) and 11 known compounds (2–12) were separated from the N. sativa seeds by chromatographic methods. Their structures were then elucidated by spectroscopic analysis of MS, UV, IR, ¹H-, and ¹³C-NMR. Furthermore, immunomodulatory effects of those compounds in RAW 264.7 cells were evaluated by phagocytosis, nitric oxide (NO) and cytokine release, related mRNA transcription, and key proteins expression in vitro. Monosaccharide derivatives, Ethyl-α-D-furaarabinose (5), and Ethyl-β-D-fructofuranoside (8) were shown to played bidirectional regulatory roles in immunity and anti-inflammation through the regulation of nuclear factor-κB (NF-κB) signaling pathways. The results showed the active compounds and mechanisms of immune regulation in N. sativa, thus indicating that N. sativa seeds could be used as dietary supplements in immunomodulation.