Gymnemic Acid Ameliorates Hyperglycemia through PI3K/AKT- and AMPK-Mediated Signaling Pathways in Type 2 Diabetes Mellitus Rats

Microbial creation of β-Nicotinamide mononucleotide and its regulation of lipid metabolism in the liver of high-fat diet mice

β-Nicotinamide mononucleotide (NMN) is a biologically active nucleotide that regulates the physiological metabolism of the body by rapidly increasing nicotinamide adenine dinucleotide (NAD+). To determine the safety and biological activity of NMN resources, we constructed a recombinant strain of P. pastoris that heterologously expresses nicotinamide-phosphate ribosyltransferase (NAMPT), and subsequently catalyzed and purified the expressed product to obtain NMN. Consequently, this study established a high-fat diet (HFD) obese model to investigate the lipid-lowering activity of NMN. The findings showed that NMN supplementation directly increased the NAD+ levels, and reduced HFD-induced liver injury and lipid deposition. NMN treatment significantly decreased total cholesterol (TC) and triglyceride (TG) in serum and liver, as well as alanine aminotransferase (ALT) and insulin levels in serum (p < .05 or p < .01). In conclusion, this study combined synthetic biology with nutritional evaluation to confirm that P. pastoris-generated NMN modulated lipid metabolism in HFD mice, offering a theoretical framework and evidence for the application of microbially created NMN.

Alleviation of hepatic insulin resistance and steatosis with NMN via improving endoplasmic reticulum-Mitochondria miscommunication in the liver of HFD mice

The interaction between endoplasmic reticulum (ER) and mitochondria has been shown to play a key role in hepatic steatosis during chronic obesity. β-nicotinamide mononucleotide (NMN) has been reported to regulate obesity, however, its molecular mechanism at the subcellular level remains unclear. Here, NMN improved liver steatosis and insulin resistance in chronic high-fat diet (HFD) mice. RNA-seq showed that compared with the liver of HFD mice, NMN intervention enhanced fat digestion and absorption and stimulated the cholesterol metabolism signaling pathways, while impaired insulin resistance and the fatty acid biosynthesis signaling pathways. Mechanistically, NMN ameliorated mitochondrial dysfunction and ER oxidative stress in the liver of HFD mice by increasing hepatic nicotinamide adenine dinucleotide (NAD+) (P < 0.01) levels. This effect increased the contact sites (mitochondria-associated membranes [MAMs]) between ER and mitochondria, thereby promoting intracellular ATP (P < 0.05) production and mitigating lipid metabolic disturbances in the liver of HFD mice. Taken together, this study provided a theoretical basis for restoring metabolic dynamic equilibrium in the liver of HFD mice by increasing MAMs via the nutritional strategy of NMN supplementation.

Identification of a potentially functional circRNA-miRNA-mRNA regulatory network in type 2 diabetes mellitus by integrated microarray analysis

BACKGROUND

Circular RNAs (circRNAs) function as miRNA sponges by adsorbing microRNAs (miRNAs), thereby regulating messenger RNA (mRNA) expression. The circRNA-miRNA-mRNA regulatory network associated with type 2 diabetes mellitus (T2DM) has rarely been explored. A circRNA-miRNA-mRNA regulatory network associated with T2DM was established to help deepen our understanding of the molecular mechanism of and therapeutic targets for T2DM.

METHODS

Differentially expressed circRNAs (DEcircRNAs), miRNAs (DEmiRNAs), and mRNAs (DEmRNAs) were derived from the Gene Expression Omnibus (GEO) microarray datasets GSE114248, GSE51674 and GSE95849, respectively. A circRNA-miRNA-mRNA regulatory network associated with T2DM and its subnetwork were constructed. The hub genes were screened using a protein-protein interaction (PPI) network. Finally, a hub gene-related network was constructed. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed.

RESULTS

The circRNA-miRNA-mRNA network included 9 circRNAs, 24 miRNAs and 320 mRNAs. When four key circRNAs (circMYO9B, circGRAMD1B, circTHAP4 and circTMC7) were chosen, the subnetwork contained 4 circRNAs, 18 miRNAs and 307 mRNAs. Afterwards, 8 hub genes (SIRT1, GNG7, KDR, FOS, SIN3B, STAT1, SP1, and MAPK3) were extracted from the PPI network. GO and KEGG pathway analyses revealed that the network might be involved in oxidative stress responses, regulation of inflammation, neovascularization, endocrine and cancer-related processes, etc.

CONCLUSIONS

A circRNA-miRNA-hub gene regulatory network was constructed, and the potential functions of the hub genes were analyzed. Four important circRNAs (circMYO9B, circGRAMD1B, circTHAP4 and circTMC7) might be involved in the occurrence and development of T2DM, and this finding provides new insight into the molecular mechanism of and therapeutic targets for T2DM and its complications. Future studies are needed to validate the sponge effects and mechanisms of these 4 circRNAs.

Flavonoids, Isoflavonoids and others Bioactives for Insulin Sensitizations

Diabetes is a chronic condition that has an impact on a huge part of the world. Both animals and humans have been demonstrated to benefit from natural goods, and organisms (animals, or microbes). In 2021, approximately 537 million adults (20-79 years) are living with diabetes, making it the one of the biggest cause of death worldwide. Various phytoconstituent preserved β- cells activity helps to prevent the formation of diabetes problems. As a result, β-cells mass and function are key pharmaceutical targets. The purpose of this review is to provide an overview of flavonoids' effects on pancreatic β-cells. Flavonoids have been demonstrated to improve insulin release in cell lines of isolated pancreatic islets and diabetic animal models. Flavonoids are thought to protect β-cells by inhibiting nuclear factor-κB (NF-κB) signaling, activating the phosphatidylinositol 3-kinase (PI3K) pathway, inhibiting nitric oxide production, and lowering reactive oxygen species levels. Flavonoids boost β-cells secretory capacity by improving mitochondrial bioenergetic function and increasing insulin secretion pathways. Some of the bioactive phytoconstituents such as S-methyl cysteine sulfoxides stimulate insulin synthesis in the body and increase pancreatic output. The berberine increased insulin secretion in the HIT-T15 and Insulinoma 6 (MIN6) mouse cell line. Epigallocatechin-3-Gallate protects against toxicity accrued by cytokines, reactive oxygen species (ROS), and hyperglycemia. Quercetin has been proven to boost insulin production by Insulinoma 1 (INS-1) cells and also protect cell apoptosis. Overall flavonoids have beneficial effects on β-cells by prevented their malfunctioning or degradation and improving synthesis or release of insulin from β-cells.

Identification of Potential Plant-Derived Pancreatic Beta-Cell-Directed Agents Using New Custom-Designed Screening Method: Gymnema sylvestre as an Example

BACKGROUND

Folk medicines are attractive therapeutic agents for treating type 2 diabetes mellitus (T2DM). Most plant extracts that have been suggested to restore β-cells function were tested in vivo. Some only have been tested in vitro to determine whether they have a direct effect on β-cells islets of Langerhans. Currently, there are no defined criteria for screening of β-cell-directed plant-based remedies as potential antidiabetic agents.

SUMMARY

In this review, we have identified certain criteria/characteristics that can be used to generate a "screening portfolio" to identify plant extracts as potential β-cell-directed agents for the treatment of T2DM. To validate our screening method, we studied the potential therapeutic efficacy of a Gymnema sylvestre (GS) extract using the screening criteria detailed in the review. Six criteria have been identified and validated using OSA®, a GS extract. By using this screening method, we show that OSA® fulfilled most of the criteria identified for an effective β-cell-directed antidiabetic therapy, being an effective insulin-releasing agent at nontoxic concentrations; maintaining β-cell insulin content by stimulating a concomitant increase in insulin gene transcription; maintaining β-cell mass by protecting against apoptosis; and being effective at maintaining normoglycemia in vivo in a mouse model and a human cohort with T2DM.

KEY MESSAGES

The present review has highlighted the importance of having a screening portfolio for plant extracts that have potential antidiabetic effects in the treatment of T2DM. We propose that this screening method should be adopted for future studies to identify new β-cell-directed antidiabetic plant derived agents.

Potential Application of Marine Fucosyl-Polysaccharides in Regulating Blood Glucose and Hyperglycemic Complications

Diabetes mellitus (DM) has become the world's third major disease after tumors and cardiovascular disease. With the exploitation of marine biological resources, the efficacy of using polysaccharides isolated from marine organisms in blood glucose regulation has received widespread attention. Some marine polysaccharides can reduce blood glucose by inhibiting digestive enzyme activity, eliminating insulin resistance, and regulating gut microbiota. These polysaccharides are mainly fucose-containing sulphated polysaccharides from algae and sea cucumbers. It follows that the hypoglycemic activity of marine fucosyl-polysaccharides is closely related to their structure, such as their sulfate group, monosaccharide composition, molecular weight and glycosidic bond type. However, the structure of marine fucosyl-polysaccharides and the mechanism of their hypoglycemic activity are not yet clear. Therefore, this review comprehensively covers the effects of marine fucosyl-polysaccharides sources, mechanisms and the structure-activity relationship on hypoglycemic activity. Moreover, the potential regulatory effects of fucosyl-polysaccharides on vascular complications caused by hyperglycemia are also summarized in this review. This review provides rationales for the activity study of marine fucosyl-polysaccharides and new insights into the high-value utilization of marine biological resources.

Triterpenoid saponins and C21 steroidal glycosides from Gymnema tingens and their glucose uptake activities

Four new triterpenoid saponins, tigensides A-D (1-4), and one new C21 steroid, tipregnane A(9), together with six known compounds were isolated from the EtOAc fraction of the roots and stems of Gymnema tingens. The chemical structures of the new compounds were determined based on their spectroscopic data, including IR, UV, NMR, and mass spectrometric analysis. All compounds were isolated for the first time. Compounds 1-11 promoted glucose uptake in the range of 1.12 to 2.52 fold, respectively. Compound 2 showed the most potent glucose uptake, with 2.52 fold enhancement. Additionally, compound 2 showed a medium effect on the GLUT4 translocation activity in L6 cells in further study.

Bioinformatics Analysis of Next Generation Sequencing Data Identifies Molecular Biomarkers Associated With Type 2 Diabetes Mellitus

Background

Type 2 diabetes mellitus (T2DM) is the most common metabolic disorder. The aim of the present investigation was to identify gene signature specific to T2DM.

Methods

The next generation sequencing (NGS) dataset GSE81608 was retrieved from the gene expression omnibus (GEO) database and analyzed to identify the differentially expressed genes (DEGs) between T2DM and normal controls. Then, Gene Ontology (GO) and pathway enrichment analysis, protein-protein interaction (PPI) network, modules, miRNA (micro RNA)-hub gene regulatory network construction and TF (transcription factor)-hub gene regulatory network construction, and topological analysis were performed. Receiver operating characteristic curve (ROC) analysis was also performed to verify the prognostic value of hub genes.

Results

A total of 927 DEGs (461 were up regulated and 466 down regulated genes) were identified in T2DM. GO and REACTOME results showed that DEGs mainly enriched in protein metabolic process, establishment of localization, metabolism of proteins, and metabolism. The top centrality hub genes APP, MYH9, TCTN2, USP7, SYNPO, GRB2, HSP90AB1, UBC, HSPA5, and SQSTM1 were screened out as the critical genes. ROC analysis provides prognostic value of hub genes.

Conclusion

The potential crucial genes, especially APP, MYH9, TCTN2, USP7, SYNPO, GRB2, HSP90AB1, UBC, HSPA5, and SQSTM1, might be linked with risk of T2DM. Our study provided novel insights of T2DM into genetics, molecular pathogenesis, and novel therapeutic targets.

Olive Leaves Extract and Oleuropein Improve Insulin Sensitivity in 3T3-L1 Cells and in High-Fat Diet-Treated Rats via PI3K/AkT Signaling Pathway

Olive leaves extracts are known to exert potential pharmacological activities especially, antidiabetic and antiobesity. This study explores the anti-insulin resistant effect of olive leaves extracts and oleuropein in 3 T3-L1 cells and in high-fat diet fed rats. Our results showed that ethanol extract (EE) suppressed significantly (P < 0.01) triacylglycerol accumulation. In preadipocytes cells, EE 1/100 decreased cell viability and induced apoptosis. Real-time PCR analysis showed that EE reduced the mRNA levels of adipogenesis (CEBP-α, PPARγ, SREBP-1c, and FAS) and proinflammatory (TNF-α and IL-6) genes. Moreover, the cotreatment of EE 1/1000 or oleuropein with insulin increased considerably the expression of p-IRS, p85-pI3K, and p-AKT. In vivo model, the oral administration of oleuropein at 50 mg/kg in rats fed with high fat diet for 8 weeks reduced inflammation in liver and adipose tissues (WAT), improved glucose intolerance, and decreased hyperinsulinemia. Furthermore, the immunohistochemistry revealed that the expression level of p-Akt, IRS1, and Glut-4 were significantly enhanced in liver and WAT tissues after oleuropein supplementation comparing with that in HFD group. Additionally, the expression of IRS1 was markedly ameliorated in pancreas. Our obtained results can be adopted as an approach to used olive leaves as complement to prevent insulin-resistance disease.

A systematic analysis of anti-diabetic medicinal plants from cells to clinical trials

Background

Diabetes is one of the fastest-growing health emergencies of the 21st century, placing a severe economic burden on many countries. Current management approaches have improved diabetic care, but several limitations still exist, such as decreased efficacy, adverse effects, and the high cost of treatment, particularly for developing nations. There is, therefore, a need for more cost-effective therapies for diabetes management. The evidence-based application of phytochemicals from plants in the management of diseases is gaining traction.

Methodology

Various plants and plant parts have been investigated as antidiabetic agents. This review sought to collate and discuss published data on the cellular and molecular effects of medicinal plants and phytochemicals on insulin signaling pathways to better understand the current trend in using plant products in the management of diabetes. Furthermore, we explored available information on medicinal plants that consistently produced hypoglycemic effects from isolated cells to animal studies and clinical trials.

Results

There is substantial literature describing the effects of a range of plant extracts on insulin action and insulin signaling, revealing a depth in knowledge of molecular detail. Our exploration also reveals effective antidiabetic actions in animal studies, and clear translational potential evidenced by clinical trials.

Conclusion

We suggest that this area of research should be further exploited in the search for novel therapeutics for diabetes.

Ginsenoside Rd attenuated hyperglycemia via Akt pathway and modulated gut microbiota in streptozotocin-induced diabetic rats

Ginsenoside Rd is a protopanaxadiol abundant in Panax ginseng and Panax notoginseng. It has been reported that ginsenoside Rd possesses various health benefits, such as anti-diabetic, anti-tumor and anti-inflammatory. This work explored the effects of ginsenoside Rd on hyperglycemia and gut microbiota in streptozotocin-induced diabetic rats. Results showed that 5-week ginsenoside Rd (20 mg/kg) treatment significantly improved hyperglycemia in diabetic rats. Besides, ginsenoside Rd promoted glycogen synthesis via activating Akt pathway. It also inhibited hepatic gluconeogenesis, which was associated with inhibiting phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. We further found that ginsenoside Rd treatment increased the diversity of gut microbiota, increased the abundance of beneficial bacteria, such as SMB53, rc4-4 and Ruminococcus, and reduced the abundance of conditional pathogenic bacteria. These results indicated that ginsenoside Rd has the potential for diabetic intervention.

Acanthopanax trifoliatus (L.) Merr polysaccharides ameliorates hyperglycemia by regulating hepatic glycogen metabolism in type 2 diabetic mice

INTRODUCTION

Drug monotherapy was inadequate in controlling blood glucose levels and other comorbidities. An agent that selectively tunes multiple targets was regarded as a new therapeutic strategy for type 2 diabetes. Acanthopanax trifoliatus (L.) Merr polysaccharide (ATMP) is a bio-macromolecule isolated from Acanthopanax trifoliatus (L.) Merr and has therapeutic potential for diabetes management due to its anti-hyperglycemia activity.

METHODS

Type 2 diabetes mellitus was induced in mice using streptozotocin, and 40 and 80 mg/kg ATMP was administered daily via the intragastric route for 8 weeks. Food intake, water intake, and body weight were recorded. The fasting blood glucose (FBG), fasting insulin (FINS) and an oral glucose tolerance test (OGTT) were performed. Histological changes in the liver and pancreas were analyzed by H&E staining. The mRNA and the protein levels of key factors involved in glycogen synthesis, glycogenolysis, and gluconeogenesis were measured by quantitative real time PCR and Western blotting.

RESULTS

In this study, we found that ATMP could effectively improve glucose tolerance and alleviate insulin resistance by promoting insulin secretion and inhibiting glucagon secretion. In addition, ATMP decreases glycogen synthesis by inhibiting PI3K/Akt/GSK3β signaling, reduces glycogenolysis via suppressing cAMP/PKA signaling, and suppresses liver gluconeogenesis by activating AMPK signaling.

CONCLUSION

Together, ATMP has the potential to be developed as a new multitargets therapeutics for type 2 diabetes.

Fructus Zanthoxyli extract improves glycolipid metabolism disorder of type 2 diabetes mellitus via activation of AMPK/PI3K/Akt pathway: Network pharmacology and experimental validation

OBJECTIVE

This study investigated the potential mechanisms behind the beneficial effects of Fructus Zanthoxyli (FZ) against type 2 diabetes mellitus (T2DM) based on network pharmacology and experimental validation.

METHODS

Ultra-high-performance liquid chromatography coupled with hybrid quadrupole-orbitrap high-resolution mass spectrometry, and gas chromatography-mass spectrometry were used to identify the constituents of FZ. Next, the differentially expressed genes linked to the treatment of diabetes with FZ were screened using online databases (including Gene Expression Omnibus database and Swiss Target Prediction online database), and the overlapping genes and their enrichment were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG). Finally, the pathway was verified by in vitro experiments, and cell staining with oil red and Nile red showed that the extract of FZ had a therapeutic effect on T2DM.

RESULTS

A total of 43 components were identified from FZ, and 39 differentially expressed overlapping genes were screened as the possible targets of FZ in T2DM. The dug component-target network indicated that PPARA, PPARG, PIK3R3, JAK2 and GPR88 might be the core genes targeted by FZ in the treatment of T2DM. Interestingly, the enrichment analysis of KEGG showed that effects of FZ against T2DM were closely correlated with the adenosine monophosphate-activated protein kinase (AMPK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) signaling pathways. In vitro experiments further confirmed that FZ significantly inhibited palmitic acid-induced lipid formation in HepG2 cells. Moreover, FZ treatment was able to promote the AMPK and PI3K/Akt expressions in HepG2 cells.

CONCLUSION

Network pharmacology combined with experimental validation revealed that FZ extract can improve the glycolipid metabolism disorder of T2DM via activation of the AMPK/PI3K/Akt pathway.

Impairment of insulin signaling pathway PI3K/Akt/mTOR and insulin resistance induced AGEs on diabetes mellitus and neurodegenerative diseases: a perspective review

Insulin resistance is common in type 2 diabetes mellitus (T2DM), neurodegenerative diseases, cardiovascular diseases, kidney diseases, and polycystic ovary syndrome. Impairment in insulin signaling pathways, such as the PI3K/Akt/mTOR pathway, would lead to insulin resistance. It might induce the synthesis and deposition of advanced glycation end products (AGEs), reactive oxygen species, and reactive nitrogen species, resulting in stress, protein misfolding, protein accumulation, mitochondrial dysfunction, reticulum function, and metabolic syndrome dysregulation, inflammation, and apoptosis. It plays a huge role in various neurodegenerative diseases like Parkinson's disease, Alzheimer's disease, Huntington's disease, and Amyloid lateral sclerosis. In this review, we intend to focus on the possible effect of insulin resistance in the progression of neurodegeneration via the impaired P13K/Akt/mTOR signaling pathway, AGEs, and receptors for AGEs.

Polysaccharide from Hemerocallis citrina Borani by subcritical water: Bioactivity, purification, characterization, and anti-diabetic effects in T2DM rats

Hemerocallis citrina Borani (daylily) has various health benefits. However, the structural characterization and hypoglycemic effects of its polysaccharide remain unclear. Here, we first report for the first time, the effects of subcritical water extraction temperature on bioactivity of Hemerocallis citrina Borani polysaccharide (HCBP). HCBP extracted at 160 °C had better scavenging ability of free-radical and pancreatic lipase inhibition. This study aimed to investigate the structural characterization and anti-diabetic effects of aforementioned HCBP. HCBP was separated into three fractions using a DEAE-Sepharose Fast Flow. HCBP-1 was the major component with lower molecular weight, HCBP-2 was the least abundant component, HCBP-3 was the component with higher uronic acid and molecular weight. HCBP treatment significantly decreased the concentrations of fasting blood glucose, insulin, total cholesterol, triglyceride, and low density lipoprotein, as well as improved glucose intolerance and insulin resistance in type 2 diabetes mellitus (T2DM) rats. HCBP also protected the kidneys and pancreatic organs by histopathology and immunohistochemical analyses in T2DM rats. In addition, HCBP significantly increased the antioxidant enzymes activities and decreased the level of malonaldehyde to alleviated the oxidative stress injury. The results indicate HCBP extracted by subcritical water is promising functional food ingredients and could be used in T2DM treatment.

The Beneficial Effects of Two Polysaccharide Fractions from Sargassum fusiform against Diabetes Mellitus Accompanied by Dyslipidemia in Rats and Their Underlying Mechanisms

The current study aimed to assess the anti-diabetic effects and potential mechanisms of two Sargassum fusiform polysaccharide fractions (SFPs, named SFP-1 and SFP-2). The carbohydrate-loading experiment revealed that SFP-2 could control postprandial hyperglycemia by inhibiting the activity of digestive enzymes in rats. The analysis of diabetic symptoms and serum profiles indicated that SFPs could mitigate diabetes accompanied by dyslipidemia, and SFP-2 showed better regulatory effects on body weight, food intake and the levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C) and free fatty acid (FFA) in diabetic rats. Intestinal bacterial analysis showed that SFP treatment could reshape the gut flora of diabetic rats, and SFP-2 possessed a greater regulatory effect on the growth of Lactobacillus and Blautia than SFP-1. RT-qPCR analysis revealed that SFPs could regulate the genes involved in the absorption and utilization of blood glucose, hepatic glucose production and lipid metabolism, and the effects of SFP-2 on the relative expressions of Protein kinase B (Akt), Glucose-6-phosphatase (G-6-Pase), Glucose transporter 2 (GLUT2), AMP-activated protein kinase-α (AMPKα), Peroxisome proliferator-activated receptor γ (PPARγ) and Cholesterol 7-alpha hydroxylase (CYP7A1) were greater than SFP-1. All above results indicated that SFPs could be exploited as functional foods or pharmaceutical supplements for the treatment of diabetes and its complications.

Targeting NRF2 in Type 2 diabetes mellitus and depression: Efficacy of natural and synthetic compounds

Evidence supports a strong bidirectional association between depression and Type 2 diabetes mellitus (T2DM). The harmful impact of oxidative stress and chronic inflammation on the development of both disorders is widely accepted. Nuclear factor erythroid 2-related factor 2 (NRF2) is a pertinent target in disease management owing to its reputation as the master regulator of antioxidant responses. NRF2 influences the expression of various cytoprotective phase 2 antioxidant genes, which is hampered in both depression and T2DM. Through interaction and crosstalk with several signaling pathways, NRF2 endeavors to contain the widespread oxidative damage and persistent inflammation involved in the pathophysiology of depression and T2DM. NRF2 promotes the neuroprotective and insulin-sensitizing properties of its upstream and downstream targets, thereby interrupting and preventing disease advancement. Standard antidepressant and antidiabetic drugs may be powerful against these disorders, but unfortunately, they come bearing distressing side effects. Therefore, exploiting the therapeutic potential of NRF2 activators presents an exciting opportunity to manage such bidirectional and comorbid conditions.

Oxidative stress in the pathophysiology of type 2 diabetes and related complications: Current therapeutics strategies and future perspectives

Type 2 diabetes (T2DM) is a persistent metabolic disorder rising rapidly worldwide. It is characterized by pancreatic insulin resistance and β-cell dysfunction. Hyperglycemia induced reactive oxygen species (ROS) production and oxidative stress are correlated with the pathogenesis and progression of this metabolic disease. To counteract the harmful effects of ROS, endogenous antioxidants of the body or exogenous antioxidants neutralise it and maintain bodily homeostasis. Under hyperglycemic conditions, the imbalance between the cellular antioxidant system and ROS production results in oxidative stress, which subsequently results in the development of diabetes. These ROS are produced in the endoplasmic reticulum, phagocytic cells and peroxisomes, with the mitochondrial electron transport chain (ETC) playing a pivotal role. The exacerbated ROS production can directly cause structural and functional modifications in proteins, lipids and nucleic acids. It also modulates several intracellular signaling pathways that lead to insulin resistance and impairment of β-cell function. In addition, the hyperglycemia-induced ROS production contributes to micro- and macro-vascular diabetic complications. Various in-vivo and in-vitro studies have demonstrated the anti-oxidative effects of natural products and their derived bioactive compounds. However, there is conflicting clinical evidence on the beneficial effects of these antioxidant therapies in diabetes prevention. This review article focused on the multifaceted role of oxidative stress caused by ROS overproduction in diabetes and related complications and possible antioxidative therapeutic strategies targeting ROS in this disease.

Isolation, purification, structural characterization, and hypoglycemic activity assessment of polysaccharides from Hovenia dulcis (Guai Zao)

Hovenia dulcis polysaccharides (HDPs) have a variety of important biological activities associated with potential applications in food engineering, pharmacy science, and health care. Herein, we isolated and purified polysaccharides from H. dulcis. Chemical composition analysis revealed that the purified polysaccharides (HDPs-2A) were composed of different molar ratios of mannose, Rha, GalA, GlcA, Glc, Gal, and Ara and had a molecular weight of 372.91 kDa. The structure of HDPs-2A was assessed by FT-IR, periodate oxidation, Smith degradation, methylation analysis, and NMR, allowing us to determine that the backbone of HDPs-2A is composed primarily of →5)-α-L-Araf-(1→, →5)-α-L-Araf-(1→, →3,5)-α-L-Araf-(1→, →6)-β-D-Galp-(1→, →3,6)-β-D-Galp-(1→, T-β-D-Galp, →3)-β-D-Galp-(1→, and T-α-D-Glcp. The results of atomic force microscopy (AFM) showed that HDPs-2A present an irregular polymer particle morphology in water. X-ray diffraction (XRD) results showed that HDPs-2A have a single crystal structure. Finally, we demonstrated that HDPs-2A have a good therapeutic effect on a rat model of type 2 diabetes.

Ameliorated effects of a lipopeptide surfactin on insulin resistance in vitro and in vivo

Surfactin, produced by Bacillus amyloliquefaciens fmb50, was used to treat insulin‐resistant (IR) hepatocyte. It was found that surfactin increased glucose consumption in insulin‐resistant HepG2 (IR‐HepG2) cells and ameliorated IR by increasing glucose transporter 4 (GLUT4) protein expression and AMP‐activated protein kinase (AMPK) mRNA expression, promoting GLUT4 translocation and activating phosphatidylinositol 3‐kinase (PI3K)/protein kinase B (Akt) in IR‐HepG2 cells. Meanwhile, surfactin downregulated protein expression of phosphoenolpyruvate carboxy kinase (PEPCK) and glucose‐6‐phosphatase (G6Pase), further inhibiting hepatic gluconeogenesis. In addition, surfactin played important roles in eliminating reactive oxygen species (ROS), improving mitochondrial dysfunction, and inhibiting proinflammatory mediators. We observed that surfactin promoted glucose consumption, meanwhile increased translocation and protein expression of GLUT4 in Caco‐2 cells. These results confirmed the conclusion in hepatic cells. Furthermore, surfactin supplement decreased body weight, food intake, and fasting blood glucose of type 2 diabetes mellitus (T2DM) mice induced by streptozotocin (STZ)/high‐fat diet (HFD). Our data indicated that surfactin ameliorated insulin resistance and lowered blood glucose in intro and in vivo.

Recent developments made in the assessment of the antidiabetic potential of gymnema species - From 2016 to 2020

BACKGROUND

In traditional herbal medicine, the Gymnema species has been well known for various therapeutic activities such as anti-diabetic, anti-inflammatory, anti-bacterial, anti-arthritic, anti-hyperlipidemic, cytotoxic, and immunostimulatory activities. This review is an effort to analyse all the recent studies done to explore the anti-diabetic potential of traditional Gymnema species. Gymnema sylvestre (Retz.) R.Br. ex Sm. is an important member of the Apocynaceae family that has been used to treat a variety of diseases, the most studied of which is diabetes. This action is mostly due to the pharmacologically active phytoconstituents present in its extract, which include gymnemic acids, triterpenoid saponin glycosides, and so on. Numerous other Gymnema species have also demonstrated a similar pharmacological action.

INTRODUCTION

The goal of this study is to give a critical overview of the available data on Gymnema species that are used to treat diabetes. The major goal of this study is to give up-to-date knowledge on ethnopharmacology, botany, pharmacology, and structure-activity relationships of Gymnemaspecies from 2016 to 2020, as well as potential future research. The potential of using medicinal plants for alleviating symptoms of diabetes is recently being recognized. This review aims to summarize the available data and highlight both the potential and shortcomings of using Gymnema therapeutically. This knowledge can further be used to develop more therapeutically effective drugs derived from Gymnema.

MATERIALS AND METHODS

Data for Gymnema species was obtained using a mix of several search terms from online databases such as PubMed, SCOPUS, and Europe PMC. Other literature surveys relevant to traditional knowledge, phytochemistry, pharmacology, or structure-activity relationship activity were also used as reference. Several methods by which Gymnema species extracts exert their effects have been investigated, and a summary of the newly discovered chemicals isolated from the plant in the previous five years has been provided.

RESULTS

SAR based evaluation has been carried out for a total of 27 pharmacologically active compounds belonging to three species of Gymnema genus (Gymnema sylvestre, Gymnema latifolium, and Gymnema inodorum).These compounds demonstrated the critical significance of plant medicines for diabetes management. Numerous heterocyclic compounds have anti-diabetic action and may serve as a starting point for the design and identification of new diabetes inhibitors.

CONCLUSIONS

This study aims to provide researchers with a better understanding of the antidiabetic potential Gymnema species, as well as an outline of prospective future developments. It was concluded after studying the evaluation done in the last 5 years that although extracts of Gymnema have shown good antidiabetic potential, further modifications in the structures could result in the development of more potent and safer compounds.

Antidiabetic Effects of Bifidobacterium longum subsp. longum BL21 through Regulating Gut Microbiota Structure in Type 2 Diabetic Mice

Bifidobacterium longum subsp. longum BL21 (BL21) possess hypoglycemic activity, but its anti-diabetic mechanism has rarely been illustrated. In the present work, the effect of BL21 on type 2 diabetes mellitus...

Botanical Interventions to Improve Glucose Control and Options for Diabetes Therapy

Diabetes mellitus is a major public health problem worldwide. This endocrine disease is clustered into distinct subtypes based on the route of development, with the most common forms associated with either autoimmunity (T1DM) or obesity (T2DM). A shared hallmark of both major forms of diabetes is a reduction in function (insulin secretion) or mass (cell number) of the pancreatic islet beta-cell. Diminutions in both mass and function are often present. A wide assortment of plants have been used historically to reduce the pathological features associated with diabetes. In this review, we provide an organized viewpoint focused around the phytochemicals and herbal extracts investigated using various preclinical and clinical study designs. In some cases, crude extracts were examined directly, and in others, purified compounds were explored for their possible therapeutic efficacy. A subset of these studies compared the botanical product with standard of care prescribed drugs. Finally, we note that botanical formulations are likely suspects for future drug discovery and refinement into class(es) of compounds that have either direct or adjuvant therapeutic benefit.

Auricularia auricula-judae (Bull.) polysaccharides improve type 2 diabetes in HFD/STZ-induced mice by regulating the AKT/AMPK signaling pathways and the gut microbiota

Auricularia auricula-judae is an edible fungus with high nutritional value due to abundant polysaccharides, and is acknowledged as traditional food and medicine in Asia. Polysaccharides from A. auricula (AAPs) are typically fungal polysaccharides and have a wide range of biological activities. It has been shown the potential of AAPs to improve diabetes as an effective adjuvant, but the underlying mechanism remains unclear. In this study, we explored the effects and potential mechanism of AAPs on type 2 diabetes (T2D) using a high-fat diet and streptozotocin (STZ) induced C57BL/6J mice. The results indicated that 50 and 100 mg/kg AAPs significantly decreased inflammation, liver injury, and insulin resistance. In addition, AAPs improved glycolipid metabolism disorders by activating the AKT and adenosine 5`monophosphate-activated protein kinase (AMPK) signaling pathways in T2D mice. Furthermore, we investigated the association between changes of gut microbiota and AAPs effects using high-throughput sequencing of 16S rDNA for fecal samples. In our study, AAPs elevated gut microbiota diversity and optimized microbial composition and function in T2D mice, characterized by increased Lactobacillus and Bacteroides abundance and decreased Clostridium and Allobaculum abundance. Particularly, AAPs intervention mainly affected the amino acid metabolism and glycolipid metabolism pathways. Overall, this study confirms that AAPs can improve type 2 diabetes by regulating the AKT and AMPK pathways and modulating intestinal microbiota. PRACTICAL APPLICATION: The article systematically verified the positive effects of AAPs on insulin resistance, glycolipid metabolism disorder, inflammation, and liver injury, key factors closely related to T2D. Furthermore, our study firstly determined the specific underlying mechanism that AAPs ameliorates T2D through regulating AKT/AMPK pathways and modifying the gut microbiota. These results could offer a full explanation and a potential option for the adjuvant therapy of diabetes with AAPs.

Identification of C21 Steroidal Glycosides from Gymnema sylvestre (Retz.) and Evaluation of Their Glucose Uptake Activities

Gymnema sylvestre (Retz.) Schult is a multi-purpose traditional medicine that has long been used for the treatment of various diseases. To discover the potential bioactive composition of G. sylvestre, a chemical investigation was thus performed. In this research, four new C₂₁ steroidal glycosides sylvepregosides A-D (1–4) were isolated along with four known compounds, gymnepregoside H (5), deacetylkidjoladinin (6), gymnepregoside G (7) and gymnepregoside I (8), from the ethyl acetate fraction of G. sylvestre. The structures of the new compounds were established by extensive 1D and 2D nuclear magnetic resonance (NMR) spectra with mass spectroscopy data. Compounds 1–6 promoted glucose uptake by the range of 1.10- to 2.37-fold, respectively. Compound 1 showed the most potent glucose uptake, with 1.37-fold enhancement. Further study showed that compounds 1 and 5 could promote GLUT-4 fusion with the plasma membrane in L6 cells. The result attained in this study indicated that the separation and characterization of these compounds play an important role in the research and development of new anti-diabetic drugs and pharmaceutical industry.

Catalpol Weakens Depressive-like Behavior in Mice with Streptozotocin-induced Hyperglycemia via PI3K/AKT/Nrf2/HO-1 Signaling Pathway

Depression has huge social risks of high incidence, disability, and suicide. Its prevalence and harm in people with hyperglycemia are 2-3 times higher than in normal people. However, antidepressants with precise curative effects and clear mechanisms for patients with hyperglycemia are currently lacking. Prescriptions containing Rehmannia glutinosa, a traditional medicinal herb with a wide range of nutritional and medicinal values, are often used as antidepressants in Chinese clinical medicine. Catalpol is one of the main effective compounds of R. glutinosa, with multiple biological activities such as hypoglycemia. Here, the antidepressant effect of catalpol on the pathological state of streptozotocin (STZ)-induced hyperglycemia and the underlying molecular mechanisms were analyzed. Results showed that administering catalpol orally to hyperglycemic mice for 21 consecutive days significantly reversed the abnormalities in tail suspension, forced swimming, and open field tests. Catalpol also reversed the abnormal phosphorylation of phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) and the abnormal levels of nuclear factor erythroid 2-related factor 2 (Nrf2) protein, heme oxygenase-1 (HO-1), and antioxidants, including superoxide dismutase, glutathione peroxidase, glutathione-s transferase, reduced glutathione, and malondialdehyde in the hippocampus and frontal cortex of STZ-induced hyperglycemic mice. Thus, catalpol attenuates depressive-like behavior in pathological hyperglycemic state, and the antidepressant mechanism could at least be partly attributed to the upregulation of the PI3K/AKT/Nrf2/HO-1 signaling pathway in both brain regions, thus restoring the balance between oxidative and antioxidant damage. These data expanded the scientific understanding of catalpol and provided preclinical experimental evidence for its application.

The hyperglycemic regulatory effect of sprouted quinoa yoghurt in high-fat-diet and streptozotocin-induced type 2 diabetic mice via glucose and lipid homeostasis

Recently, we have proposed that quinoa yoghurt (QY) has the anti-diabetic properties based on an in vitro study. Here, its antidiabetic activity was further validated by investigating its hypoglycemic and hypolipidemic influence in high fat diet/streptozotocin-induced type 2 diabetes mellitus (T2DM) mice. The results showed that QY increased the body weights of and reduced the fasting blood glucose levels in T2DM mice. QY significantly (p < 0.05) reduced the serum levels of total cholesterol, triglyceride and LDL-C, while it increased the HDL-C level. In addition, the hepatic glycogen content, and superoxide dismutase, catalase, and glutathione peroxidase activities were significantly (p < 0.05) increased, while lipid peroxidation was remarkably reduced. Sprouted QY had the highest influence on serum oxidation when compared with non-germinated QY. The level of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) were significantly (p < 0.05) decreased, while the level of anti-inflammatory cytokine IL-10 was increased. Histopathological studies showed that QY protected the tissue structure of the liver of T2DM mice. Immunohistochemistry showed that QY increased AKT-2 and AMPK-α2 expressions, while it suppressed p85. The qRT-PCR analysis indicated that QY exerted its hypoglycemic and anti-hyperlipidemic effects through the AKT/AMPK/PI3K signaling pathway. Germination significantly (p < 0.05) influenced the glucose and lipid homeostasis in T2DM mice in such a way that sprouted QY showed the highest hypoglycemic and cholesterol-lowering effects when compared with non-germinated QY.

Chrysin Improves Glucose and Lipid Metabolism Disorders by Regulating the AMPK/PI3K/AKT Signaling Pathway in Insulin-Resistant HepG2 Cells and HFD/STZ-Induced C57BL/6J Mice

Natural products with minor side effects have been reported to be an effective adjuvant therapy for glucose and lipid metabolism disorders. Chrysin, a flavone, has a wide range of physiological effects, such as antioxidant, anti-inflammatory, anti-diabetes, anti-hyperlipidemia, and hepatoprotective. This study was designed to explore the effects and mechanism of chrysin on metabolic syndrome using insulin-resistant HepG2 cells and HFD/STZ-induced C57BL/6J mice. The results indicated that chrysin significantly decreased insulin resistance, oxidative stress, inflammation, and liver injury. In addition, chrysin improved glycogen synthesis and fatty acid oxidation and inhibited gluconeogenesis and fatty acid synthesis by regulating GSK3β, G6Paes, PEPCK, SREBP1, FAS, and ACC1. Furthermore, the results of western blot and real-time PCR experiments demonstrated that chrysin modulated glucose and lipid metabolism through the AMPK/PI3K/AKT signaling pathway. Treatment with the AMPK inhibitor verified that AMPK activation is positively correlated with chrysin activity on glycolipid metabolism. This study confirms that chrysin is a potential treatment for glucose and lipid metabolism disorders.

Overview of key molecular and pharmacological targets for diabetes and associated diseases

Diabetes epidemiological quantities are demonstrating one of the most important communities' health worries. The essential diabetic difficulties are including cardiomyopathy, nephropathy, inflammation, and retinopathy. Despite developments in glucose decreasing treatments and drugs, these diabetic complications are still ineffectively reversed or prohibited. Several signaling and molecular pathways are vital targets in the new therapies of diabetes. This review assesses the newest researches about the key molecules and signaling pathways as targets of molecular pharmacology in diabetes and diseases related to it for better treatment based on molecular sciences. The disease is not cured by current pharmacological strategies for type 2 diabetes. While several drug combinations are accessible that can efficiently modulate glycemia and mitigate long-term complications, these agents do not reverse pathogenesis, and in practice, they are not established to modify the patient's specific molecular profiling. Therapeutic companies have benefited from human genetics. Genome exploration, which is agnostic to the information that exists, has revealed tens of loci that impact glycemic modulation. The physiological report has begun to examine subtypes of diseases, illustrate heterogeneity and propose biochemical therapeutic pathways.

Zanthoxylum alkylamides ameliorate protein metabolism in type 2 diabetes mellitus rats by regulating multiple signaling pathways

Type 2 diabetes mellitus (T2DM) can easily induce insulin resistance (IR) in skeletal muscle, causing protein metabolism disorder and inflammation. The present study aimed to investigate whether Zanthoxylum alkylamides (ZA) could ameliorate T2DM through regulating protein metabolism disorder by using a rat model of T2DM. The predominant bioactive constituents found in ZA were hydroxyl-α-sanshool, hydroxyl-β-sanshool and hydroxyl-γ-sanshool. The results showed that ZA improved a series of biochemical indices associated with protein metabolism and inflammation in T2DM rats. Our mechanistic finding indicated that ZA promoted protein anabolism in T2DM rats by up-regulating the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. ZA also promoted glucose transportation in skeletal muscle to ameliorate skeletal muscle IR and energy metabolism through regulating the AMP-activated protein kinase (AMPK) signaling pathway. Moreover, ZA inhibited protein degradation and improved protein catabolism disorder in T2DM rats by down-regulating the PI3K/Akt/forkhead box O (FoxO) signaling pathway, and ZA further ameliorated inflammation to inhibit protein catabolism via regulating the tumor necrosis factor α (TNF-α)/nuclear factor κB (NF-κB) pathway in the skeletal muscle of T2DM rats. Collectively, the ameliorating effect of ZA on protein metabolism disorder in T2DM rats was the common result of regulating multiple signaling pathways. ZA decreased skeletal muscle IR to promote protein anabolism and inhibit protein catabolism for improving protein metabolism disorder, thus ultimately ameliorating T2DM. In sum, our findings demonstrated that ZA treatment could effectively ameliorate T2DM through improving protein metabolism, providing a new treatment target for T2DM.

L-Arabinose suppresses gluconeogenesis through modulating AMP-activated protein kinase in metabolic disorder mice

l-Arabinose is a kind of plant-specific five-carbon aldose with benefits in type 2 diabetes mellitus. It has been shown to have good properties in improving glucose homeostasis, but the underlying molecular mechanisms are still not clear. Hepatic gluconeogenesis is critical for regulating glucose homeostasis. Here, this study aimed to investigate whether l-arabinose could improve glucose metabolism via suppressing hepatic gluconeogenesis. High-fat-high-sucrose diet (HFHSD) or high-sucrose diet (HSD)-fed mice were supplemented with or without l-arabinose for 12 weeks. Fasting blood glucose levels were measured and glucose tolerance test and the histological analysis were performed after l-arabinose administration. AMP-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), peroxisome proliferator activated receptor-γ coactivator-1α (PGC1α), Forkhead box O1 (FoxO1), phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) expression levels were determined by RT-PCR and western blotting. As expected, l-arabinose apparently decreased body weight and attenuated hyperglycemia and glucose intolerance caused by HFHSD or HSD. l-Arabinose also had beneficial effects on glycogen synthesis by inactivating GSK3β. The expression levels of gluconeogenic genes were all decreased by l-arabinose administration in vivo and in vitro. In addition, our work revealed that AMPK is required for the inhibitory effects of l-arabinose on hepatic gluconeogenesis. l-Arabinose significantly up-regulated the phosphorylated levels of AMPK and its downstream protein ACC. Furthermore, blocking AMPK signaling through an inhibitor (compound C) or siAMPK significantly attenuated the inhibition of hepatic gluconeogenesis and the promotion of glycogen synthesis with l-arabinose, indicating that the inhibitory effect of l-arabinose on hepatic gluconeogenesis was AMPK dependent. Our work revealed that l-arabinose is a promising natural product for the regulation of hyperglycemia through inhibition of hepatic gluconeogenesis by activating AMPK.

The Possible Role of Saponin in Type-II Diabetes- A Review

BACKGROUND

The possible role of secondary metabolites in the management of diabetes is a great concern and constant discussion. This characteristic seems relevant and should be the subject of thorough discussion with respect to saponin.

OBJECTIVE

The current data mainly focus on the impact of saponin in the treatment of type-II diabetes. The majority of studies emphasize on other secondary metabolites such as alkaloids and flavonoids, but very few papers are there representing the possible role of saponin as these papers express the narrow perspective of saponin phytoconstituents but lacking in providing the complete information on various saponin plants. The aim of the study was to summarize all available data concerning the saponin containing plant in the management of type-II diabetes.

METHODS

All relevant papers on saponin were selected. This review summarizes the saponin isolation method, mechanism of action, clinical significance, medicinal plants and phytoconstituents responsible for producing a therapeutic effect in the management of diabetes.

RESULTS

The saponin is of high potential with structural diversity and inhibits diabetic complications along with reducing the hyperglycemia through different mechanisms thereby providing scope for improving the existing therapy and developing the novel medicinal agents for curing diabetes.

CONCLUSION

Saponins having potential therapeutic benefits and are theorized as an alternative medication in decreasing serum blood glucose levels in the patient suffering from diabetes.

Polysaccharides from Armillariella tabescens mycelia ameliorate insulin resistance in type 2 diabetic mice

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterized by hyperglycemia mainly due to insulin resistance. The objective of this study was to investigate the effects of polysaccharides from Armillariella tabescens mycelia (AT) on insulin resistance in mice fed a high-fat diet in combination with streptozotocin to induce T2DM. Following treatment with different doses of AT, hyperglycemia and lipid metabolism dysfunction, insulin resistance, and hepatic function-related indices were markedly ameliorated; the histopathological alterations, oxidative stress, and inflammatory reaction in hepatic tissue were also alleviated; most importantly, AT inhibited the expression of hepatic thioredoxin-interacting protein (TXNIP) to repress the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation and activated the 5'AMP-activated protein kinase (AMPK) pathway in a dose-dependent manner in T2DM mice. In conclusion, these findings revealed that the hypoglycemic and hypolipidemic activities of AT were associated with the alleviation of insulin resistance through repression of the TXNIP/NLRP3 inflammasome pathway and activation of the AMPK pathway.

Eurocristatine, a plant alkaloid from Eurotium cristatum, alleviates insulin resistance in db/db diabetic mice via activation of PI3K/AKT signaling pathway

Eurocristatine (ECT) is an alkaloid isolated from Eurotium cristatum, and it has been used in multiple applications. However, its use as a treatment for type 2 diabetes mellitus (T2DM) has not yet been reported. In this study, we investigated the anti-T2DM effect of ECT and explored its potential molecular mechanism. In vivo, after treatment with ECT (20, 40 mg/kg) for 6 weeks, fasting blood glucose (FBG) was remarkably reduced in db/db mice. Moreover, glucose tolerance, insulin sensitivity and hyperinsulinemia were ameliorated treatment with ECT. The values of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) also showed that ECT could alleviate liver toxicity caused by diabetes in db/db mice. In vitro, ECT (15 and 30 μM) alleviated insulin resistance by increasing glucose consumption, glucose uptake and glycogen content in high glucose-induced HepG2 cells. The Western blotting (WB) results showed that ECT could upregulate the expression of phosphatidylinositol 3-kinase (PI3K), increase the phosphorylation of insulin receptor substrate 1 (IRS1) and protein kinase B (AKT) in vivo and in vitro. Besides, ECT improved the glycogen content by inhibiting the expression of glycogen synthase kinase3β (GSK3β) and promoting that of glycogen synthase (GS). Furthermore, administration of the PI3K/AKT signaling pathway inhibitor LY294002 abolished the beneficial effects of ECT. These findings are the first to verify that ECT has the potential to improve glucose metabolism and alleviate insulin resistance by activating the PI3K/AKT signaling pathway in db/db mice.

Sulfated fucan/fucosylated chondroitin sulfate-dominated polysaccharide fraction from low-edible-value sea cucumber ameliorates type 2 diabetes in rats: New prospects for sea cucumber polysaccharide based-hypoglycemic functional food

Sulfated fucan chondroitin sulfate-dominated polysaccharide fraction from low-edible-value sea cucumber may be a good alternative to high-edible-value sea cucumber-derived polysaccharide for application in hypoglycemic functional foods. To evaluate the potential effect of low-edible-value sea cucumber-derived polysaccharide fraction on type 2 diabetes (T2DM), two sulfated fucan/fucosylated chondroitin sulfate-dominated polysaccharide fractions screening from 10 global commercial low-edible-value sea cucumber species were investigated to identify their anti-diabetics efficacies using a high-fat diet and streptozotocin-induced T2DM rat model. Sulfated fucan-dominated polysaccharide fraction from Thelenota ananas and fucosylated chondroitin sulfate-dominated polysaccharide fraction from Cucumaria frondosa ameliorated hyperglycemia, restored hypertriglyceridemia and hypercholesterolemia, decreased inflammatory status and oxidative stress, protected against liver injury, as well as improved insulin resistance and promoted accumulation of hepatic glycogen by activating IRS/PI3K/AKT signaling and regulating GSK-3β gene expression in T2DM rats. The current findings provide an available strategy for the commercialization of sea cucumber polysaccharide based-hypoglycemic functional food.