Astragalus polysaccharides alleviate type 1 diabetes via modulating gut microbiota in mice

Neuroprotective Effects of Astragalus Polysaccharide on Retina Cells and Ganglion Cell Projection in NMDA-Induced Retinal Injury

PURPOSE

Astragalus polysaccharide (APS), a water-soluble heteropolysaccharide, possesses immunomodulatory, anti-inflammatory, and cardioprotective properties. This study investigates the neuroprotective potential of APS in a model of N-Methyl-d-aspartic acid (NMDA)-induced retinal neurodegeneration, aiming to explore its potential as a treatment for retinal degenerative diseases.

METHODS

Retinal function was evaluated using electroretinography (ERG), optomotor reflex (OMR), and flash visual evoked potentials (FVEP). Retinal inflammatory responses were examined through immunohistochemistry, western blotting (WB), and quantitative reverse transcription PCR (qRT-PCR). To assess the integrity of visual projections, an intravitreal injection of adeno-associated virus (AAV) was employed to trace the projections of retinal ganglion cells (RGCs) to the visual centers.

RESULTS

APS treatment conferred protection to retinal cells, as indicated by ERG and OMR assessments. And APS intervention mitigated NMDA-induced apoptosis, evidenced by a decrease in TUNEL-positive cells. Furthermore, APS treatment attenuated the NMDA-induced reduction in RGC projections to the visual centers, including the superior colliculus and lateral geniculate nucleus, as demonstrated by AAV tracing.

CONCLUSIONS

Our findings reveal that APS shields the retina from NMDA-induced damage by inhibiting the NF-κB signaling pathway and reduces the detrimental effects of NMDA on RGC projections to the visual centers. These findings propose APS as a potential novel therapeutic agent for the treatment of retinal diseases.

Astragali radix (Huangqi): a time-honored nourishing herbal medicine

Astragali radix (AR, namded Huangqi in Chinese) is the dried root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao or Astragalus membranaceus (Fisch.) Bge. As a widely used ethnomedicine, the biological activities of AR include immunomodulatory, anti-hyperglycemic, anti-oxidant, anti-aging, anti-inflammatory, anti-viral, anti-tumor, cardioprotective, and anti-diabetic effects, with minimum side effects. Currently, it is known that polysaccharides, saponins, and flavonoids are the indispensable components of AR. In this review, we will elaborate the research advancements of AR on ethnobotany, ethnopharmacological practices, phytochemicals, pharmacological activities, clinical uses, quality control, production developments, and toxicology. The information is expected to assist clinicians and scientists in developing useful therapeutic medicines with minimal systemic side effects.

Progress on the Anti-Inflammatory Activity and Structure-Efficacy Relationship of Polysaccharides from Medical and Edible Homologous Traditional Chinese Medicines

Medicinal food varieties developed according to the theory of medical and edible homologues are effective at preventing and treating chronic diseases and in health care. As of 2022, 110 types of traditional Chinese medicines from the same source of medicine and food have been published by the National Health Commission. Inflammation is the immune system's first response to injury, infection, and stress. Chronic inflammation is closely related to many diseases such as atherosclerosis and cancer. Therefore, timely intervention for inflammation is the mainstay treatment for other complex diseases. However, some traditional anti-inflammatory drugs on the market are commonly associated with a number of adverse effects, which seriously affect the health and safety of patients. Therefore, the in-depth development of new safe, harmless, and effective anti-inflammatory drugs has become a hot topic of research and an urgent clinical need. Polysaccharides, one of the main active ingredients of medical and edible homologous traditional Chinese medicines (MEHTCMs), have been confirmed by a large number of studies to exert anti-inflammatory effects through multiple targets and are considered potential natural anti-inflammatory drugs. In addition, the structure of medical and edible homologous traditional Chinese medicines' polysaccharides (MEHTCMPs) may be the key factor determining their anti-inflammatory activity, which makes the underlying the anti-inflammatory effects of polysaccharides and their structure-efficacy relationship hot topics of domestic and international research. However, due to the limitations of the current analytical techniques and tools, the structures have not been fully elucidated and the structure-efficacy relationship is relatively ambiguous, which are some of the difficulties in the process of developing and utilizing MEHTCMPs as novel anti-inflammatory drugs in the future. For this reason, this paper summarizes the potential anti-inflammatory mechanisms of MEHTCMPs, such as the regulation of the Toll-like receptor-related signaling pathway, MAPK signaling pathway, JAK-STAT signaling pathway, NLRP3 signaling pathway, PI3K-AKT signaling pathway, PPAR-γ signaling pathway, Nrf2-HO-1 signaling pathway, and the regulation of intestinal flora, and it systematically analyzes and evaluates the relationships between the anti-inflammatory activity of MEHTCMPs and their structures.

Astragalus polysaccharide alleviates IL-13-induced oxidative stress injury in nasal epithelial cells by inhibiting WTAP-mediated FBXW7 m6A modification

Background

Allergic rhinitis (AR) a common and complicated upper airway disease mediated by specific IgE antibodies. Our study aims to explore the pharmacological effects of astragalus polysaccharide (APS) on AR and elucidate the mechanisms involved.

Methods

RT-qPCR and Western blotting were used to analyze mRNA and protein expression. Interleukin (IL)-13-treated human nasal epithelial cells (hNECs) was employed as the AR cell model. Cell apoptosis and viability were evaluated by TUNEL staining and MTT assay, respectively. ROS level was examined by the DCFH-DA probe. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels were measured by the corresponding kits. FBXW7 m6A modification level was assessed by MeRIP assay.

Methods

Our results showed that APS treatment reduced cell apoptosis, ROS, and MDA levels while increasing SOD, CAT, and GSH-Px levels in IL-13-treated hNECs by activating the Nrf2/HO-1 pathway. Moreover, APS alleviated IL-13-induced oxidative stress injury in hNECs by downregulating WTAP. In addition, WTAP knockdown increased FBXW7 mRNA stability by regulating FBXW7 mRNA m6A modification. It also turned out that APS alleviated IL-13-induced oxidative stress injury in hNECs through the WTAP/FBXW7 axis.

Conclusions

Taken together, APS inhibited WTAP-mediated FBXW7 m6A modification to alleviate IL-13-induced oxidative stress injury in hNECs.

Termite Fungus Comb Polysaccharides Alleviate Hyperglycemia and Hyperlipidemia in Type 2 Diabetic Mice by Regulating Hepatic Glucose/Lipid Metabolism and the Gut Microbiota

Type 2 diabetes (T2D) is a chronic metabolic disorder characterized by hyperglycemia and dyslipidemia. The termite fungus comb is an integral component of nests of termites, which are a global pest. Termite fungus comb polysaccharides (TFCPs) have been identified to possess antioxidant, anti-aging, and immune-enhancing properties. However, their physicochemical characteristics and their role in fighting diabetes have not been previously reported. In the current study, TFCPs were isolated and structurally characterized. The yield of TFCPs was determined to be 2.76%, and it was found to be composed of a diverse array of polysaccharides with varying molecular weights. The hypoglycemic and hypolipidemic effects of TFCPs, as well as their potential mechanisms of action, were investigated in a T2D mouse model. The results demonstrated that oral administration of TFCPs could alleviate fasting blood glucose levels, insulin resistance, hyperlipidemia, and the dysfunction of pancreatic islets in T2D mice. In terms of mechanisms, the TFCPs enhanced hepatic glycogenesis and glycolysis while inhibiting gluconeogenesis. Additionally, the TFCPs suppressed hepatic de novo lipogenesis and promoted fatty acid oxidation. Furthermore, the TFCPs altered the composition of the gut microbiota in the T2D mice, increasing the abundance of beneficial bacteria such as Allobaculum and Faecalibaculum, while reducing the levels of pathogens like Mailhella and Acetatifactor. Overall, these findings suggest that TFCPs may exert anti-diabetic effects by regulating hepatic glucose and lipid metabolism and the composition of the gut microbiota. These findings suggest that TFCPs can be used as a promising functional ingredient for the prevention and treatment of T2D.

Progress of plant-derived non-starch polysaccharides and their challenges and applications in future foods

The development of future food is devoted not only to obtaining a sustainable food supply but also to providing high-quality foods for humans. Plant-derived non-starch polysaccharides (PNPs) are widely available, biocompatible, and nontoxic and have been largely applied to the food industry owing to their mechanical properties and biological activities. PNPs are considered excellent biomaterials and food ingredients contributing to future food development. However, a comprehensive review of the potential applications of PNPs in future food has not been reported. This review summarized the physicochemical and biological activities of PNPs and then discussed the structure-activity relationships of PNPs. Latest studies of PNPs on future foods including cell-cultured meat, food for special medical purposes (FSMPs), and three-dimensional-printed foods were reviewed. The challenges and prospects of PNPs applied to future food were critically proposed. PNPs with strong thermal stability are considered good thickeners, emulsifiers, and gelatinizers that greatly improve the processing adaptability of foods. The mechanical properties of PNPs and decellularized plant-based PNPs make them desirable scaffolds for cultured meat manufacturing. In addition, the biological activities of PNPs exhibit multiple health-promoting effects; therefore, PNPs can act as food ingredients producing FSMP to promote human health. Three-dimensional printing technology enhances food structures and biological activities of functional foods, which is in favor of expanding the application scopes of PNPs in future food. PNPs are promising in future food manufacturing, and more efforts need to be made to realize their commercial applications.

Global research trends in regulating gut microbiome to improve type 2 diabetes mellitus: bibliometrics and visual analysis

Background

Gut microbiome (GM) and type 2 diabetes mellitus (T2DM) have two-way effects. Improving T2DM by modulating GM in various ways, such as diet, exercise, and medication, is gradually becoming popular, and related studies have yielded positive results. However, there is still a lack of high-quality bibliometric analyses of research in this area. This study aims to systematize and comprehensively summarize the knowledge structure, research tropics, and research trends of GM and T2DM through bibliometric analysis.

Methods

Publications related to GM and T2DM before January 9, 2024, in the Web of Science Core Collection (WOSCC) were searched in this study. Microsoft Excel 2019 was used to analyze publishing trends and CiteSpace (v.6.1.R6 Advanced) was used to analyze institutions, cited journals, references, and keywords.SCImago Graphica (v.1.0.39) was used to analyze countries/regions, institutions' collaborations, cited authors, and published journals.

Results

We finally included 1004 articles published from 2008 to 2023. The number of published articles showed an upward trend and reached its peak in 2022. China is the country with the largest number of articles, Univ Copenhagen is the institution with the largest number of articles, Fukui, Michiaki, Hamaguchi, Masahide are the scholars with the largest number of articles, and Cani and Patrice D. are the scholars with the largest number of citations. NUTRIENTS(Q1/5.9) published the most publications, while Nature (Q1/64.8; Cited 804 times) is the most frequently cited journal. Gut microbiota, Obesity, and insulin resistance are the most frequently used keywords. This study found that current researches focus on the effects of diet, exercise, and pharmacological modification of GM to improve T2DM and explores specific mechanisms. Future researches will focus on three areas: complications of T2DM and specific physiological processes, methods and measures to regulate GM, and new experimental techniques and assays.

Conclusion

The current researches confirmed the effects and specific mechanisms of modulating GM to improve T2DM. Further exploration of the effects of modulating GM on T2DM complications and specific physiologic processes is a future trend of research. Exploring specific methods for regulating GM and developing new experimental techniques and assays are important for future research.

Structural characterization of squash polysaccharide and its effect on STZ-induced diabetes mellitus model in MIN6 cells

A novel natural water-soluble acidic polysaccharide (PWESP-3) was isolated from squash with a molecular mass of 140.519 kDa, which was composed of arabinose (Ara, 35.30 mol%), galactose (Gal, 61.20 mol%), glucose (Glc, 1.80 mol%), and Mannuronic acid (ManA, 1.70 mol%) and contained Araf-(1→, →3)-Araf-(1→, →5)-Araf-(1→, Glcp-(1→, Galp-(1→, →3,5)-Araf-(1→, →2)-Glcp-(1→, →2)-Manp-(1→, →3)-Glcp-(1→, →4)-Galp-(1→, →3)-Galp-(1→, →6)-Galp-(1→, →3,4)-Galp-(1→, →4,6)-Galp-(1→ residues in the backbone. Moreover, the structure of PWESP-3 was identified by NMR spectra. The branch chain was connected to the main chain by the O-3 and O-4 atom of Gal. In addition, the effect of PWESP-3 on STZ-induced type I diabetes mellitus model in MIN6 cells was investigated. The results showed that PWESP-3 can increase the viability and insulin secretion of MIN6 cells and reduce the oxidative stress caused by ROS and NO. Meanwhile, PWESP-3 can also reduce the content of ATP, Ca2+, mitochondrial membrane potential and Caspase-3 activity in MIN6 cells. Furthermore, treatment with PWESP-3 can prevent single or double stranded DNA breaking to form DNA fragments and improve DNA damage in MIN6 cells, thereby avoiding apoptosis. Therefore, the above data highlight that PWESP-3 can improve the function of insulin secretion in STZ-induced MIN6 cells in vitro and can be used as an alternative food supplement to diabetes drugs.

Astragalus Polysaccharide Modulates the Gut Microbiota and Metabolites of Patients with Type 2 Diabetes in an In Vitro Fermentation Model

This study investigated the effect of astragalus polysaccharide (APS, an ingredient with hypoglycemic function in a traditional Chinese herbal medicine) on gut microbiota and metabolites of type 2 diabetes mellitus (T2DM) patients using a simulated fermentation model in vitro. The main components of APS were isolated, purified, and structure characterized. APS fermentation was found to increase the abundance of Lactobacillus and Bifidobacterium and decrease the Escherichia-Shigella level in the fecal microbiota of T2DM patients. Apart from increasing propionic acid, APS also caused an increase in all-trans-retinoic acid and thiamine (both have antioxidant properties), with their enrichment in the KEGG pathway associated with thiamine metabolism, etc. Notably, APS could also enhance fecal antioxidant properties. Correlation analysis confirmed a significant positive correlation of Lactobacillus with thiamine and DPPH-clearance rate, suggesting the antioxidant activity of APS was related to its ability to enrich some specific bacteria and upregulate their metabolites.

The potential of astragalus polysaccharide for treating diabetes and its action mechanism

Type 2 diabetes presents a significant global health burden and is frequently linked to serious clinical complications, including diabetic cardiomyopathy, nephropathy, and retinopathy. Astragalus polysaccharide (APS), extracted from Astragalus membranaceus, exhibits various biochemical and physiological effects. In recent years, a growing number of researchers have investigated the role of APS in glucose control and the treatment of diabetes and its complications in various diabetes models, positioning APS as a promising candidate for diabetes therapy. This review surveys the literature on APS from several databases over the past 20 years, detailing its mechanisms of action in preventing and treating diabetes mellitus. The findings indicate that APS can address diabetes by enhancing insulin resistance, modulating the immune system, protecting islet cells, and improving the intestinal microbiota. APS demonstrates positive pharmacological value and clinical potential in managing diabetic complications, including diabetic retinopathy, nephropathy, cardiomyopathy, cognitive dysfunction, wound healing, and more. However, further research is necessary to explore APS's bioavailability, optimal dosage, and additional clinical evidence.

Astragali Radix: comprehensive review of its botany, phytochemistry, pharmacology and clinical application

Astragali Radix (A. Radix) is the dried root of Astragalus membranaceus var. mongholicus (Bge) Hsiao or Astragalus membranaceus (Fisch.) Bge., belonging to the family Leguminosae, which is mainly distributed in China. A. Radix has been consumed as a tonic in China for more than 2000 years because of its medicinal effects of invigorating the spleen and replenishing qi. Currently, more than 400 natural compounds have been isolated and identified from A. Radix, mainly including saponins, flavonoids, phenylpropanoids, alkaloids, and others. Modern pharmacological studies have shown that A. Radix has anti-tumor, anti-inflammatory, immunomodulatory, anti-atherosclerotic, cardioprotective, anti-hypertensive, and anti-aging effects. It has been clinically used in the treatment of tumors, cardiovascular diseases, and cerebrovascular complications associated with diabetes with few side effects and high safety. This paper reviewed the progress of research on its chemical constituents, pharmacological effects, clinical applications, developing applications, and toxicology, which provides a basis for the better development and utilization of A. Radix.

Effects and mechanisms of anti-diabetic dietary natural products: an updated review

Diabetes is a global public health issue, characterized by an abnormal level of blood glucose. It can be classified into type 1, type 2, gestational, and other rare diabetes. Recent studies have reported that many dietary natural products exhibit anti-diabetic activity. In this narrative review, the effects and underlying mechanisms of dietary natural products on diabetes are summarized based on the results from epidemiological, experimental, and clinical studies. Some fruits (e.g., grape, blueberry, and cherry), vegetables (e.g., bitter melon and Lycium barbarum leaves), grains (e.g., oat, rye, and brown rice), legumes (e.g., soybean and black bean), spices (e.g., cinnamon and turmeric) and medicinal herbs (e.g., Aloe vera leaf and Nigella sativa), and vitamin C and carotenoids could play important roles in the prevention and management of diabetes. Their underlying mechanisms include exerting antioxidant, anti-inflammatory, and anti-glycation effects, inhibiting carbohydrate-hydrolyzing enzymes, enhancing insulin action, alleviating insulin resistance, modulating the gut microbiota, and so on. This review can provide people with a comprehensive knowledge of anti-diabetic dietary natural products, and support their further development into functional food to prevent and manage diabetes.

Recent advances in medicinal and edible homologous plant polysaccharides: Preparation, structure and prevention and treatment of diabetes

Medicinal and edible homologs (MEHs) can be used in medicine and food. The National Health Commission announced that a total of 103 kinds of medicinal and edible homologous plants (MEHPs) would be available by were available in 2023. Diabetes mellitus (DM) has become the third most common chronic metabolic disease that seriously threatens human health worldwide. Polysaccharides, the main component isolated from MEHPs, have significant antidiabetic effects with few side effects. Based on a literature search, this paper summarizes the preparation methods, structural characterization, and antidiabetic functions and mechanisms of MEHPs polysaccharides (MEHPPs). Specifically, MEHPPs mainly regulate PI3K/Akt, AMPK, cAMP/PKA, Nrf2/Keap1, NF-κB, MAPK and other signaling pathways to promote insulin secretion and release, improve glycolipid metabolism, inhibit the inflammatory response, decrease oxidative stress and regulate intestinal flora. Among them, 16 kinds of MEHPPs were found to have obvious anti-diabetic effects. This article reviews the prevention and treatment of diabetes and its complications by MEHPPs and provides a basis for the development of safe and effective MEHPP-derived health products and new drugs to prevent and treat diabetes.

Intermittent Fasting on Neurologic Diseases: Potential Role of Gut Microbiota

As the global population ages, the prevalence of neurodegenerative diseases is surging. These disorders have a multifaceted pathogenesis, entwined with genetic and environmental factors. Emerging research underscores the profound influence of diet on the development and progression of health conditions. Intermittent fasting (IF), a dietary pattern that is increasingly embraced and recommended, has demonstrated potential in improving neurophysiological functions and mitigating pathological injuries with few adverse effects. Although the precise mechanisms of IF's beneficial impact are not yet completely understood, gut microbiota and their metabolites are believed to be pivotal in mediating these effects. This review endeavors to thoroughly examine current studies on the shifts in gut microbiota and metabolite profiles prompted by IF, and their possible consequences for neural health. It also highlights the significance of dietary strategies as a clinical consideration for those with neurological conditions.

A Multi-Component Nano-Co-Delivery System Utilizing Astragalus Polysaccharides as Carriers for Improving Biopharmaceutical Properties of Astragalus Flavonoids

Purpose

Enhancing the dissolution, permeation and absorption of active components with low solubility and poor permeability is crucial for maximizing therapeutic efficacy and optimizing functionality. The objective of this study is to investigate the potential of natural polysaccharides as carriers to improve the biopharmaceutical properties of active components.

Methods

In this study, we employed four representative flavonoids in Astragali Radix, namely Calycosin-7-O-β-D-glucoside (CAG), Ononin (ON), Calycosin (CA) and Formononetin (FMN), as a demonstration to evaluate the potential of Astragalus polysaccharides (APS) as carriers to improve the biopharmaceutical properties, sush as solubility, permeability, and absorption in vivo. In addition, the microstructure of the flavonoids-APS complexes was characterized, and the interaction mechanism between APS and flavonoids was investigated using multispectral technique and molecular dynamics simulation.

Results

The results showed that APS can self-assemble into aggregates with a porous structure and large surface area in aqueous solutions. These aggregates can be loaded with flavonoids through weak intermolecular interactions, such as hydrogen bonding, thereby improving their gastrointestinal stability, solubility, permeability and absorption in vivo.

Conclusion

We discovered the self-assembly properties of APS and its potential as carriers. Compared with introducing external excipients, the utilization of natural polysaccharides in plants as carriers may have a unique advantage in enhancing dissolution, permeation and absorption.