Chicory inulin ameliorates type 2 diabetes mellitus and suppresses JNK and MAPK pathways in vivo and in vitro

Valorization of cell wall polysaccharides extracted from Liubao brick tea residues: chemical, structural, and hypoglycemic properties

BACKGROUND

Tea dregs, typically generated during the production of instant tea or tea beverages, have conventionally been regarded as waste material and routinely discarded. Nevertheless, contemporary research endeavors are concentrating on discovering efficient methods for utilizing the potential of this discarded resource.

RESULTS

In this study, we employed a sequential extraction method using chemical chelating agents to extract and isolate four distinct cell wall polysaccharides, designated as CWTPS-1 through CWTPS-4, from the tea dregs of Liubao brick tea. A comprehensive investigation into their physicochemical, structural, and hypoglycemic properties was conducted. The analysis of chemical composition and physicochemical characteristics revealed that all four CWTPSs were characterized as acidic polysaccharides, albeit with varying chemical compositions and physicochemical attributes. Specifically, the xyloglucan fractions, CWTPS-3 and CWTPS-4, were found to be rich in glucose and xylose, displaying a more uniform molecular weight distribution, greater structural stability, and a more irregular surface compared to the others. Moreover, they exhibited a higher diversity of monosaccharide residues. Importantly, our research unveiled that all four CWTPSs exhibited the capacity to modulate key glucose-regulated and antioxidant enzyme activities within HepG2 cells via the IRS-1-PI3K/AKT signaling pathway, thereby ameliorating cellular insulin resistance. Furthermore, our correlation analysis highlighted significant associations between monosaccharide composition and neutral sugar content with the observed hypoglycemic activity of CWTPSs.

CONCLUSION

This study highlights the potential of utilizing tea dregs as a valuable resource, making a significant contribution to the advancement of the tea industry. Furthermore, CWTPS-4 exhibits promising prospects for further development as a functional food ingredient or additive. © 2024 Society of Chemical Industry.

Antidiabetic Potential of Tea and Its Active Compounds: From Molecular Mechanism to Clinical Evidence

Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic β-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.

The Effect of Microbiome-Modulating Agents (MMAs) on Type 1 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Gut microbiome-modulating agents (MMAs), including probiotics, prebiotics, postbiotics, and synbiotics, are shown to ameliorate type 1 diabetes (T1D) by restoring the microbiome from dysbiosis. The objective of this systematic review and meta-analysis was to assess the impact of MMAs on hemoglobin A1c (HbA1c) and biomarkers associated with (T1D). A comprehensive search was conducted in PubMed, Web of Science, Embase, Cochrane Library, National Knowledge Infrastructure, WeiPu, and WanFang Data up to 30 November 2023. Ten randomized controlled trials (n = 630) were included, with study quality evaluated using the Cochrane risk-of-bias tool. Random-effect models with standardized mean differences (SMDs) were utilized. MMA supplementation was associated with improvements in HbA1c (SMD = -0.52, 95% CI [-0.83, -0.20]), daily insulin usage (SMD = -0.41, 95% confidence interval (CI) [-0.76, -0.07]), and fasting C-peptide (SMD = 0.99, 95% CI [0.17, 1.81]) but had no effects on FBG, CRP, TNF-α, IL-10, LDL, HDL, and the Shannon index. Subgroup analysis of HbA1c indicated that a long-term intervention (>3 months) might exert a more substantial effect. These findings suggest an association between MMAs and glycemic control in T1D. Further large-scale clinical trials are necessary to confirm these findings with investigations on inflammation and gut microbiota composition while adjusting confounding factors such as diet, physical activity, and the dose and form of MMA intervention.

The synergism of Lactobacillaceae, inulin, polyglucose, and aerobic exercise ameliorates hyperglycemia by modulating the gut microbiota community and the metabolic profiles in db/db mice

This study aimed to assess the impact of Lactobacillaceae (L or H represents a low or high dose), inulin (I), and polydextrose (P) combined with aerobic exercise (A) on the composition of the gut microbiota and metabolic profiles in db/db mice. After a 12-week intervention, LIP, LIPA, and HIPA groups exhibited significant improvements in hyperglycemia, glucose tolerance, insulin resistance, inflammatory response, and short-chain fatty acid (SCFA) and blood lipid levels compared to type 2 diabetes mice (MC). After treatment, the gut microbiota composition shifted favorably in the treatment groups which significantly increased the abundance of beneficial bacteria, such as Bacteroides, Blautia, Akkermansia, and Faecalibaculum, and significantly decreased the abundance of Proteus. Metabolomics analysis showed that compared to the MC group, the contents of 5-hydroxyindoleacetic acid, 3-hydroxysebacic acid, adenosine monophosphate (AMP), xanthine and hypoxanthine were significantly decreased, while 3-ketosphinganine, sphinganine, and sphingosine were significantly increased in the LIP and LIPA groups, respectively. Additionally, LIP and LIPA not only improved sphingolipid metabolism and purine metabolism pathways but also activated AMP-activated protein kinase to promote β-oxidation by increasing the levels of SCFAs. Faecalibaculum, Blautia, Bacteroides, and Akkermansia exhibited positive correlations with sphingosine, 3-ketosphinganine, and sphinganine, and exhibited negative correlations with hypoxanthine, xanthine and AMP. Faecalibaculum, Blautia, Bacteroides, and Akkermansia may have the potential to improve sphingolipid metabolism and purine metabolism pathways. These findings suggest that the synergism of Lactobacillaceae, inulin, polydextrose, and aerobic exercise provides a promising strategy for the prevention and management of type 2 diabetes.

Edible wild plants, chicory and purslane, alleviated diabetic testicular dysfunction, and insulin resistance via suppression 8OHdg and oxidative stress in rats

Testicular dysfunction is a prevalent health problem frequently reported in individuals with diabetes mellitus (DM). Oxidative-inflammatory reactions, hormonal and spermatic abnormalities often accompany this illness. Herbal remedies "particularly wild plants" including chicory (Chicorium Intybus) and purslane (Portulaca Oleracea) are emerging as popular agents for people dealing with these issues due to their ability to act as antioxidants, reduce inflammation, and exhibit antidiabetic effects. According to the collected data, the daily administration of chicory (Ch) seed-extract (250 mg/kg) or purslane (Pu) seed-extract (200 mg/kg) to streptozotocin (STZ)-induced diabetic rats (50 mg/kg) for 30 days resulted in the normalization of fasting blood glucose (FBG), serum fructosamine, insulin levels, and insulin resistance (HOMA-IR), as well as reducing lipid peroxidation end-product malondialdehyde (MDA) level, aldehyde oxidase (AO) and xanthene oxidase (XO) activities. While caused a considerable improvement in glutathione (GSH) content, superoxide dismutase (SOD), catalase (CAT) activity, and total antioxidant capacity (TAC) when compared to diabetic rats. Ch and Pu extracts had a substantial impact on testicular parameters including sperm characterization, testosterone level, vimentin expression along with improvements in body and testis weight. They also mitigated hyperlipidemia by reducing total lipids (TL), total cholesterol (TC) levels, and low-density lipoprotein cholesterol (LDL-C), while increasing high-density lipoprotein cholesterol (HDL-C). Furthermore, oral administration of either Ch or Pu notably attuned the elevated proinflammatory cytokines as tumor necrotic factor (TNF-α), C-reactive protein (CRP), and Interleukin-6 (IL-6) together with reducing apoptosis and DNA damage. This was achieved through the suppression of DNA-fragmentation marker 8OHdG, triggering of caspase-3 immuno-expression, and elevation of Bcl-2 protein. The histological studies provided evidence supporting the preventive effects of Ch and Pu against DM-induced testicular dysfunction. In conclusion, Ch and Pu seed-extracts mitigate testicular impairment during DM due to their antihyperglycemic, antilipidemic, antioxidant, anti-inflammatory, and antiapoptotic properties.

The Synergism of Human Lactobacillaceae and Inulin Decrease Hyperglycemia via Regulating the Composition of Gut Microbiota and Metabolic Profiles in db/db Mice

This study aimed to evaluate the effects of Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from human feces coordinating with inulin on the composition of gut microbiota and metabolic profiles in db/db mice. These supplements were administered to db/db mice for 12 weeks. The results showed that the Lactobacillaceae coordinating with inulin group (LI) exhibited lower fasting blood glucose levels than the model control group (MC). Additionally, LI was found to enhance colon tissue and increase the levels of short-chain fatty acids. 16S rRNA sequencing revealed that the abundance of Corynebacterium and Proteus, which were significantly increased in the MC group compared with NC group, were significantly decreased by the treatment of LI that also restored the key genera of the Lachnospiraceae_NK4A136_group, Lachnoclostridium, Ruminococcus_gnavus_group, Desulfovibrio, and Lachnospiraceae_UCG-006. Untargeted metabolomics analysis showed that lotaustralin, 5-hydroxyindoleacetic acid, and 13(S)-HpODE were increased while L-phenylalanine and L-tryptophan were decreased in the MC group compared with the NC group. However, the intervention of LI reversed the levels of these metabolites in the intestine. Correlation analysis revealed that Lachnoclostridium and Ruminococcus_gnavus_group were negatively correlated with 5-hydroxyindoleacetic acid and 13(S)-HpODE, but positively correlated with L-tryptophan. 13(S)-HpODE was involved in the "linoleic acid metabolism". L-tryptophan and 5-hydroxyindoleacetic acid were involved in "tryptophan metabolism" and "serotonergic synapse". These findings suggest that LI may alleviate type 2 diabetes symptoms by modulating the abundance of Ruminococcus_gnavus_group and Lachnoclostridium to regulate the pathways of "linoleic acid metabolism", "serotonergic synapse", and" tryptophan metabolism". Our results provide new insights into prevention and treatment of type 2 diabetes.

Soluble Dietary Fibers as Antihyperlipidemic Agents: A Comprehensive Review to Maximize Their Health Benefits

The number of hypercholesterolemic people is increasing rapidly worldwide, with elevated lipid profiles representing a major risk factor of coronary heart diseases. Dietary intervention was shown to improve the lipid profile, thus enhancing the quality of life. Dietary fiber is a nondigestible form of carbohydrates, due to the lack of the digestive enzyme in humans required to digest fiber, and is classified according to its water solubility properties as either soluble (SDF) or insoluble dietary fiber (IDF). Consumption of SDF is associated with several health benefits such as reduced lipid levels, lower blood pressure, improved blood glucose control, improved immune function, and reduced inflammation. SDF has been shown to lower blood cholesterol by several action mechanisms including directly due to the gelling, mucilaginous, and viscous fiber nature, and indirectly due to its fermented products and modulation of the gut microbiome. This review aims to provide a holistic overview on how SDF impacts the lipid profile. We start by providing an overview of the chemical structure of the major SDFs including mucilage, gums (gum arabic and guar gum), pectin, and inulin.

Extraction, Physicochemical Properties, Functional Activities and Applications of Inulin Polysaccharide: a Review

Inulin is a naturally soluble dietary fiber that is widely distributed and primarily derived from plants. As a reserve biopolysaccharide in plants, inulin is considered an indigestible carbohydrate of fructan because of its unique β-(2,1)-glycosidic bond structure. Numerous recent animal and human experimental studies have shown that functional inulin possesses multiple bioactivities, including immunomodulatory, antioxidant, antitumor, hepatoprotective, hypoglycemic, and gastrointestinal protective activities. Due to its increasing popularity, people tend to consume foods containing inulin. Moreover, inulin holds promise as a bioactive compound for use in the development of various food products. Therefore, this paper provides a detailed review of the extraction method, physicochemical properties, functional activity, and application development of inulin polysaccharides, to provide a theoretical foundation for further advancements in the fields of preparation and application of functional foods.

From Diabetes to Diabetic Complications: Role of Autophagy

Diabetes and its complications reduce quality of life and are life-limiting. At present, diabetes treatment consists of hypoglycemic agents to control blood glucose and the use of insulin-sensitizing drugs to overcome insulin resistance. In diabetes, autophagy is impaired and thus there is poor intracellular environment homeostasis. Pancreatic β-cells and insulin target tissues are protected by enhancing autophagy. Autophagy decreases β-cell apoptosis, promotes β-cell proliferation, and alleviates insulin resistance. Autophagy in diabetes is regulated by the mammalian target of rapamycin (mTOR)/adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway and others. Autophagy enhancers can likely be used as a treatment for diabetes and its complications. This review examines the evidence linking autophagy to diabetes.

Inulin: properties and health benefits

Inulin, a soluble dietary fiber, is widely found in more than 36 000 plant species as a reserve polysaccharide. The primary sources of inulin, include Jerusalem artichoke, chicory, onion, garlic, barley, and dahlia, among which Jerusalem artichoke tubers and chicory roots are often used as raw materials for inulin production in the food industry. It is universally acknowledged that inulin as a prebiotic has an outstanding effect on the regulation of intestinal microbiota via stimulating the growth of beneficial bacteria. In addition, inulin also exhibits excellent health benefits in regulating lipid metabolism, weight loss, lowering blood sugar, inhibiting the expression of inflammatory factors, reducing the risk of colon cancer, enhancing mineral absorption, improving constipation, and relieving depression. In this review paper, we attempt to present an exhaustive overview of the function and health benefits of inulin.

Complementary and alternative medicine for glycemic control of diabetes mellitus: A systematic review

The use of complementary and alternative medicine (CAM) is increasingly popular for the management of diabetes mellitus (DM). The aim of this study was to conduct systematic review of any types of complementary and alternative medicine for glycemic control of diabetes mellitus. Four databases was used in this study, the CINAHL, PUBMED, SCOPUS, and ProQUEST. The systematic review were reported according to the PRISMA guidelines. The keywords were used according to medical subject headings (MeSH) in this study were diabetes mellitus AND complementary and alternative medicine AND blood glucose levels or blood sugar or blood glucose. Articles were limited to 2015–2021 and only in English language. We obtained 231 articles from these databases: CINAHL six articles, PUBMED 85 articles, SCOPUS 66 articles, PROQUEST 74 articles. Then, the final results recorded 17 articles. The results of a systematic review showed the effectiveness of natural products as CAM for glycemic control of DM, namely Berberis aristata/Silybum marianum, fenugreek seed, bitter melon, cinnamon or whortleberry supplements, a combination of herbal plants (C. spinosa, R. canina, and S. securigera), Nigella sativa, Mulberry juice, chicory, chamomile tea, and bell pepper juice combined with an integrated approach of yoga therapy. Mind body practices such as auditory guided imagery (AGI), qigong and tai chi exercises, and relaxation. Whole system approach, such as acupressure. Health care providers consider CAM for DM management.

Influence of Pholiota adiposa on gut microbiota and promote tumor cell apoptosis properties in H22 tumor-bearing mice

Hepatocellular carcinoma (HCC) is a common type of cancer-prevalent worldwide-and one of the causes of cancer-related deaths. In this study, ethanol extracts from Pholiota adiposa (EPA) were used to identify possible targets for HCC treatment and their effects on intestinal microflora were analyzed. Methods: Male mice were randomly assigned to groups-the model group, cyclophosphamide (25 mg/kg/d), and EPA groups, in which the mice were categorized based on the different concentrations of each compound (100, 200, and 300 mg/kg/day). Relevant biochemical indicators were detected using ELISA, H&E staining, and TUNEL assay. Four tumor apoptosis-related proteins and genes, Cleaved Caspases, BAX, Bcl-2, and VEGF, were detected by immunohistochemical staining, western blotting, and RT-PCR. The total genomic DNA was obtained from the contents of the small intestine and colon and was sequenced. The V3 + V4 regions of bacterial 16 s rDNA (from 341 to 806) were amplified. Results: The tests revealed that EPA exhibited antitumor activity in vivo by promoting apoptosis and inhibiting angiogenesis. Moreover, EPA treatment could increase beneficial and decrease harmful microflorae. These results demonstrate that EPA may be a potential therapy for HCC.

Elucidation of the interaction effect between dietary fiber and bound polyphenol components on the anti-hyperglycemic activity of tea residue dietary fiber

Dietary fiber intake is beneficial for the prevention of some chronic metabolic diseases. Considering the characteristic that dietary fiber from tea residues (TRDF) is rich in bound polyphenols, the study aimed to elucidate the interaction effect between dietary fiber components (TRDF-DF) and bound polyphenol components (TRDF-BP) on the anti-hyperglycemic activity of TRDF. A type 2 diabetes (T2D) rat model induced by high-fat diet and streptozotocin injection was applied in this study. The results showed that bound polyphenol components rather than dietary fiber components were essential for the anti-hyperglycemic activity of TRDF, as evidenced by remarkable differences in fasting blood glucose (FBG), the insulin resistance index (HOMA-IR) and the levels of serum oxidative stress between the TRDF and TRDF-DF groups, as well as the up-regulation of the expression of insulin signaling pathway-related proteins in the liver after TRDF and TRDF-BP administration. In addition, the synergistic effect between TRDF-BP and TRDF-DF components modulated gut microbiota dysbiosis and increased the content of short chain fatty acids (SCFAs) via enriching beneficial bacteria and inhibiting harmful bacteria. The role of TRDF-BP and TRDF-DF as well as their interaction effect on the anti-hyperglycemic activity of TRDF are elucidated, which can provide theoretical basis for TRDF as a dietary supplement to manage T2D.

Jerusalem artichoke inulin supplementation ameliorates hepatic lipid metabolism in type 2 diabetes mellitus mice by modulating the gut microbiota and fecal metabolome

The main focus of this study was on the protection mechanism of Jerusalem artichoke inulin (DI) against type 2 diabetes mellitus (T2DM) associated with abnormal hepatic lipid metabolism and gut microbiota dysfunction in T2DM mice.

A comprehensive mechanistic and therapeutic insight into the effect of chicory (Cichorium intybus) supplementation in diabetes mellitus: A systematic review of literature

BACKGROUND

Cichorium intybus is a rich source of terpenoids and phenolic compounds, one of the effective methods in managing and reducing the complications of chronic diseases such as diabetes mellitus. The purpose of this systematic review was to evaluate the evidence obtained from animal and human studies on the effects of chicory on metabolic indicators (such as inflammation, oxidative stress, blood sugar and dyslipidaemia) of diabetes mellitus.

MATERIALS AND METHODS

This systematic search was performed in ProQuest, PubMed, Google Scholar, Scopus, Cochrane Central Register of Controlled Trials, Embase and Science Direct databases and on articles published until August 2021. All of the animal studies and clinical trials included in this systematic review that assessed the effect of chicory on metabolic risk markers in diabetes were published in English language journals.

RESULTS

Finally, amongst 686 articles, only 23 articles met the needed criteria for further analysis. Out of 23 articles, 3 studies on humans and 20 studies on animals have been carried out. Fifteen of the 19 studies that evaluated the effect of chicory on the glycaemic index showed that Cichorium intybus improved blood glucose index (it had no effect in two human studies and three animal studies). Ten of the 13 studies evaluating the effect of Cichorium intybus on lipid profiles showed that it improved dyslipidaemia. Also, all 12 studies showed that chicory significantly reduces oxidative stress and inflammation.

CONCLUSION

According to the available evidence, Cichorium intybus might improve the glycaemic status, dyslipidaemia, oxidative stress and inflammation. However, further studies are recommended for a comprehensive conclusion about the exact mechanism of chicory in diabetic patients.

Effects of phloridzin on blood glucose and key enzyme G-6-Pase of gluconeogenesis in mice

The effects of phloridzin (PHL), main component of Malus hupehensis (MH) tea leaves, on blood glucose (BG) and glucose-6-phosphatase (G-6-Pase) were investigated to provide a basis for finding a scheme of stabilizing BG. Glucose uptake of insulin resistant HepG2 cells was measured by glucose oxidase method. Glucose tolerance, fasting BG (FBG) and postprandial BG (PBG) were determined by BG test strips. The expression of G-6-Pase was detected by Western blot. The results showed that glucose uptake was enhanced and the expression of G-6-Pase was inhibited by PHL in insulin resistant HepG2 cells. Glucose tolerance was enhanced, FBG level was increased and PBG level was decreased by PHL in mice. The expression of G-6-Pase in the liver was enhanced under fasting state, and was inhibited by the low and medium dose under postprandial state. It indicated that PHL has a positive effect on stabilizing BG in mice, which is related to bidirectional regulation of G-6-Pase activity. PRACTICAL APPLICATIONS: Malus hupehensis, edible and medicinal plant, which has been proved by long-term application and experiments that it has a good effect on stabilizing blood glucose, preventing diabetes and adjuvant treatment. Its effect is closely related to its main component PHL. Thus, MH can be used as a dietary regulating drink for daily life to maintain blood glucose. Its main ingredient is PHL, which can be developed as a candidate drug for diabetes treatment.

Assessing the effects of inulin-type fructan intake on body weight, blood glucose, and lipid profile: A systematic review and meta-analysis of randomized controlled trials

Inulin-type fructan (ITF) intake has been suggested to alleviate several features of metabolic syndrome including obesity, diabetes, and hyperlipidemia; yet, results from the human trials remained inconsistent. We aimed to systematically evaluate the effects of ITF intake on body weight, glucose homeostasis, and lipid profile on human subjects with different health status, including healthy, overweight and obese, prediabetes and diabetes, and hyperlipidemia. Weighted mean differences (WMDs) between ITF and control groups were calculated by a random-effects model. A total of 33 randomized controlled human trials were included. Significant effect of ITF intake was only observed in the diabetics, but not in the other subject groups. Specifically, ITF intervention significantly decreased the WMD of blood glucose (-0.42 mmol/L; 95% CI: -0.71, -0.14; p = .004), total cholesterol (-0.46 mmol/L; 95% CI: -0.75, -0.17; p = .002), and triglycerides (TAG) (-0.21 mmol/L; 95% CI: -0.37, -0.05; p = .01) compared with the control. The stability of these favorable effects of ITF on diabetics was confirmed by sensitivity analysis. Also, ITF tends to lower LDL cholesterol (p = .084). But body weight and blood insulin were not affected by ITF intake. It should be noted that blood glucose, total cholesterol, and LDL cholesterol exhibited high unexplained heterogeneity. In conclusion, ITF intake lowers blood glucose, total cholesterol, and TAG in the people with diabetes, and they may benefit from addition of inulin into their diets, but the underlying mechanisms responsible for these effects are inconclusive.

HPLC-MS and Network Pharmacology Analysis to Reveal Quality Markers of Huo-Xue-Jiang-Tang Yin, a Chinese Herbal Medicine for Type 2 Diabetes Mellitus

Huo-Xue-Jiang-Tang Yin (HXJTY) is a Chinese medicine formulation, which has been widely used for the treatment of various lipometabolism- and glycometabolism-related diseases in clinics. Currently, HXJTY is mainly prescribed to treat patients with type 2 diabetes mellitus (T2DM), yet its chemical and pharmacologic profiles remain to be elucidated. Here, the potential bioactive compound and action mechanism were investigated using chemical and network pharmacology analysis. A rapid HPLC-MS was employed to identify and quantify the component of HXJTY. On the basis of the identified chemical markers from HXJTY, a network pharmacology study, including target gene prediction and functional enrichment, was applied to screen out the main quality markers of HXJTY and explore its potential mechanism for the treatment of T2DM. The results showed that a total of 22 components were identified and quantified from HXJTY by HPLC-MS. Furthermore, 12 active components such as astragaloside IV, calycosin-7-O-β-D-glucoside, hydroxysafflor yellow A, and others were proposed as quality markers of HXJTY for treating T2DM based on network pharmacology analysis. In addition, 125 corresponding possible therapeutic target genes of T2DM were obtained. These target genes are mainly related to peptidase activity, hydrolase activity, phosphatase activity, and cofactor binding, suggesting the involvement of PI3K-Akt, MAPK, AGE-RAGE, and Rap1 signaling pathways in HXJTY-treated T2DM. Our results may provide a useful approach to identify potential quality markers and molecular mechanism of HXJTY for treating T2DM.

Regulatory effects of hawthorn polyphenols on hyperglycemic, inflammatory, insulin resistance responses, and alleviation of aortic injury in type 2 diabetic rats

Hawthorn polyphenol extract (HPE) is beneficial for patients with type 2 diabetes (T2D). However, the mechanism underlying its beneficial effects remains unclear. We investigated the inhibitory effects and mechanisms of HPE on insulin resistance, inflammation, and aortic injury in T2D rats, using metformin (MF) as a positive control. High-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) was used to determine the primary polyphenols in HPE. Hematoxylin & Eosin (H&E) staining was used to evaluate pathological conditions of the skeletal muscle, liver, and aorta vessels in each group. The levels of serum and intestinal tissue oxidative stress, tumor necrosis factor α (TNF-α), and inflammatory interleukin-6 (IL-6) were also assessed. Western blotting was used to evaluate protein expression levels in the associated molecular pathway. Volatile organic compounds (VOCs) from colon contents were determined using headspace-gas chromatography-ion mobility chromatography. Our results showed that supplementation with 300 mg HPE/kg body weight over four weeks significantly improved total cholesterol (TC), total triglyceride (TG), insulin, and lipopolysaccharide (LPS) levels in diabetic rats (p < 0.01). The lesions of skeletal muscle, liver, and aorta in diabetic rats were significantly improved. HPE supplementation also significantly downregulated the inflammatory factors (IL-6, TNF-α, and MCP-1) in the liver of diabetic rats via the SIRT1/AMPK/NF-κB signaling pathway. Furthermore, HPE significantly reduced insulin resistance in T2D rats by upregulating the phosphorylation of glucose absorption protein (GLUT4) and insulin resistance-associated proteins, p-IRS1, p-AKT, and p-PI3K, in the rat liver (p < 0.01). The findings show that HPE could also alleviate aortic injury by activating SIRT1 and regulating the NF-κB and Wnt2/β-catenin signaling pathways. Overall, the results of this study suggest that both HPE and MF have similar inhibitory effects on T2D in rats and that HPE could be used as a functional food component in the adjuvant treatment of T2D.

Prominent roles of ribosomal S6 kinase 4 (RSK4) in cancer

RSK4 refers to one Ser/Thr protein kinase functioning downstream pertaining to the signaling channel of protein kinase (MAPK) stimulated by Ras/mitogen. RSK4 can regulate numerous substrates impacting cells' surviving state, growing processes and proliferating process. Thus, dysregulated RSK4 active state display a relationship to several carcinoma categories, covering breast carcinoma, esophageal squamous cell carcinoma, glioma, colorectal carcinoma, lung carcinoma, ovarian carcinoma, leukemia, endometrial carcinoma, and kidney carcinoma. Whether RSK4 is a tumor suppressor gene or one oncogene remains controversial. No specific inhibiting elements for RSK4 have been found. This review briefs the existing information regarding RSK4 activating process, the function and mechanism of RSK4 in different tumors, and the research progress and limitations of existing RSK inhibitors. RSK4 may be a potential target of molecular therapy medicine in the future.

Role of Wnt signaling pathways in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) has become a major global public health issue in the twenty-first century and its incidence has increased each year. Wnt signaling pathways are a set of multi-downstream signaling pathways activated by the binding of Wnt ligands to membrane protein receptors. Wnt signaling pathways regulate protein expression and play important roles in protecting the body's normal physiological metabolism. This review describes Wnt signaling pathways, and then aims to reveal how Wnt signaling pathways participate in the occurrence and development of T2DM. We found that Wnt/c-Jun N-terminal kinase signaling was closely associated with insulin resistance, inflammatory response, and pancreatic β-cell and endothelial dysfunction. β-catenin/transcription factor 7-like 2 (TCF7L2)-mediated and calcineurin/nuclear factor of activated T cells-mediated target genes were involved in insulin synthesis and secretion, insulin degradation, pancreatic β-cell growth and regeneration, and functional application of pancreatic β-cells. In addition, polymorphisms in the TCF7L2 gene could increase risk of T2DM according to previous and the most current results, and the T allele of its variants was a more adverse factor for abnormal pancreatic β-cell function and impaired glucose tolerance in patients with T2DM. These findings indicate a strong correlation between Wnt signaling pathways and T2DM, particularly in terms of pancreatic islet dysfunction and insulin resistance, and new therapeutic targets for T2DM may be identified.

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.

Effect of Acupuncture on the p38 Signaling Pathway in Several Nervous System Diseases: A Systematic Review

Acupuncture is clinically used to treat various diseases and exerts positive local and systemic effects in several nervous system diseases. Advanced molecular and clinical studies have continually attempted to decipher the mechanisms underlying these effects of acupuncture. While a growing understanding of the pathophysiology underlying several nervous system diseases shows it to be related to inflammation and impair cell regeneration after ischemic events, the relationship between the therapeutic mechanism of acupuncture and the p38 MAPK signal pathway has yet to be elucidated. This review discusses the latest advancements in the identification of the effect of acupuncture on the p38 signaling pathway in several nervous system diseases. We electronically searched databases including PubMed, Embase, and the Cochrane Library from their inception to April 2020, using the following keywords alone or in various combinations: "acupuncture", "p38 MAPK pathway", "signaling", "stress response", "inflammation", "immune", "pain", "analgesic", "cerebral ischemic injury", "epilepsy", "Alzheimer's disease", "Parkinson's disease", "dementia", "degenerative", and "homeostasis". Manual acupuncture and electroacupuncture confer positive therapeutic effects by regulating proinflammatory cytokines, ion channels, scaffold proteins, and transcription factors including TRPV1/4, Nav, BDNF, and NADMR1; consequently, p38 regulates various phenomena including cell communication, remodeling, regeneration, and gene expression. In this review article, we found the most common acupoints for the relief of nervous system disorders including GV20, GV14, ST36, ST37, and LI4. Acupuncture exhibits dual regulatory functions of activating or inhibiting different p38 MAPK pathways, contributing to an overall improvement of clinical symptoms and function in several nervous system diseases.

Beneficial effects of Aronia melanocarpa berry extract on hepatic insulin resistance in type 2 diabetes mellitus rats

We aimed to investigate) the effects of Aronia melanocarpa berry extract (AMBE) on hepatic insulin resistance and its mechanism at the molecular level in high-fat diet (HFD)- and streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) rats. The rats were supplemented with AMBE at doses of 100 and 400 mg/kg body weight (bw) daily for 8 weeks. AMBE significantly reduced blood glucose and serum insulin levels and the homeostatic model assessment for insulin resistance score; improved glucose tolerance; increased hepatic glycogen content; and regulated glucose metabolism enzyme activity, including glucokinase, pyruvate kinase, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase in the liver. AMBE also reduced lipid accumulation and oxidative stress along with inflammation in the hepatic tissue of T2DM rats and improved hepatic function. The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was activated by AMBE through the elevation of insulin receptor substrate-2, PI3K, Akt, and glycogen synthase kinase-3β phosphorylation and glucose transporter 2, which might contribute to the promotion of glycogen synthesis and improvement of hepatic insulin resistance. AMBE shows promise as an ingredient of functional foods for alleviating hepatic insulin resistance in T2DM. PRACTICAL APPLICATION: The extract from the berries of Aronia melanocarpa (Michx.) Elliott (AMBE), with its relatively high content of polyphenolic compounds, has been shown to exert hypoglycemic effects in animal models of diabetes. Our findings support the use of A. melanocarpa as a functional food additive for the alleviation of hepatic insulin resistance and the management of glucose homeostasis in T2DM.

Bioregional Alterations in Gut Microbiome Contribute to the Plasma Metabolomic Changes in Pigs Fed with Inulin

Inulin (INU) is a non-digestible carbohydrate, known for its beneficial properties in metabolic disorders. However, whether and how gut microbiota in its regulation contributes to host metabolism has yet to be investigated. We conduct this study to examine the possible associations between the gut microbiota and circulating gut microbiota-host co-metabolites induced by inulin interventions. Plasma and intestinal site samples were collected from the pigs that have consumed inulin diet for 60 days. High-throughput sequencing was adopted for microbial composition, and the GC-TOF-MS-based metabolomics were used to characterize featured plasma metabolites upon inulin intervention. Integrated multi-omics analyses were carried out to establish microbiota-host interaction. Inulin consumption decreased the total cholesterol (p = 0.04) and glucose (p = 0.03) level in serum. Greater β-diversity was observed in the cecum and colon of inulin-fed versus that of control-fed pigs (p < 0.05). No differences were observed in the ileum. In the cecum, 18 genera were altered by inulin, followed by 17 in the colon and 6 in the ileum. Inulin increased propionate, and isobutyrate concentrations but decreased the ratio of acetate to propionate in the cecum, and increased total short fatty acids, valerate, and isobutyrate concentrations in the colon. Metabolomic analysis reveals that indole-3-propionic acid (IPA) was significantly higher, and the branched-chain amino acids (BCAA), L-valine, L-isoleucine, and L-leucine are significantly lower in the inulin groups. Mantel test and integrative analysis revealed associations between plasma metabolites (e.g., IPA, BCAA, L-tryptophan) and inulin-responsive cecal microbial genera. These results indicate that the inulin has regional effects on the intestine microbiome in pigs, with the most pronounced effects occurring in the cecum. Moreover, cecum microbiota plays a pivotal role in the modulation of circulating host metabolites upon inulin intervention.

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

Gymnemic acid (GA) isolated from Gymnema sylvestre (Retz.) Schult. has been shown to have antihyperglycemic activity; however, the molecular mechanisms governing these effects are unclear. In this study, GA (40 and 80 mg kg^-1 day^-1) was evaluated by type 2 diabetes mellitus (T2DM) rats to explore its hypoglycemic activity and underlying mechanisms of action. The results indicated that GA decreased fasting blood glucose (FBG) concentrations by 26.7% and lowered insulin concentrations by 16.1% after oral administration of GA at a dose of 80 mg kg^-1 day^-1 for 6 weeks in T2DM rats. Our data showed that real-time polymerase chain reaction and western blot indicated that GA upregulated the level of phosphatidylinositol-3-kinase (PI3K) and glycogen synthesis (GS) and promoted the phosphorylation of protein kinase B (Akt) while downregulated the expression of glycogen synthesis kinase-3β (GSK-3β) in T2DM rats. In addition, key proteins involved in adenosine monophosphate (AMP)-activated protein kinase (AMPK)-mediated gluconeogenesis [such as phosphoenolpyruvate carboxy kinase (PEPCK) and glucose-6-phosphatase (G6Pase)] were downregulated in GA-treated T2DM rats. In summary, the hypoglycemic mechanisms of GA may be related to promoting insulin signal transduction and activating PI3K/Akt- and AMPK-mediated signaling pathways in T2DM rats.

Attenuation Effects of Bulk and Nanosized ZnO on Glucose, Lipid Level, and Inflammation Profile in Obese Mice

ZnO and ZnO nanoparticles (ZnO NPs) are widely used in food packaging, food preservation, cosmetic preparation, and animal feed. ZnO is alleged showing multiple bioactivities including antimicrobial and anti-inflammation. It is hypothesized in this study that bulk ZnO and ZnO NPs could attenuate symptoms associated with high-fat-diet-induced obesity. Bulk ZnO and ZnO NPs with diameters of 30 and 90 nm were administered to high-fat-diet (HFD)-induced obese mice. Body weight, liver and fat tissue indices of ZnO-treated mice were decreased compared with those of obese mice (MOD). Blood glucose levels in oral glucose tolerant test and insulin tolerant test of ZnO-treated mice were lower than those of MOD. Serum lipid profile of ZnO-treated mice was ameliorated with lower total cholesterol, total triglyceride, and low-density lipoprotein cholesterol levels compared with that of MOD. In addition, the levels of serum IL-1β and LPS-binding protein were also decreased by ZnO treatment. Both bulk and nanosized ZnO could attenuate HFD-induced phenotypes related with obesity, but ZnO NP is more efficient to lower the fat index and bulk ZnO is better to restore the disturbed serum lipid profile.

MicroRNA-125b-5p improves pancreatic β-cell function through inhibiting JNK signaling pathway by targeting DACT1 in mice with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a progressive disease, accompanied by increased insulin resistance and deteriorating β-cell function. Previous studies have revealed that microRNA (miRNA) plays a crucial role in the treatment of T2DM. Hence, we aim to investigate the role of microRNA-125b-5p (miR-125b-5p) in pancreatic β-cell function and insulin sensitivity of mice with T2DM with the involvement of Dishevelled antagonist Dapper1 (DACT1) and the c-Jun NH2-terminal kinases (JNK) signaling pathway. Firstly, a mouse model of T2DM was established by administering a high-fat diet plus low dosage of streptozotocin, and function of pancreatic β-cell and insulin sensitivity in the normal and T2DM mice were detected. Then, the pancreatic β-cells were collected from pancreatic islet tissues and treated with different mimics, inhibitors and siRNAs. After that, the relationship among miR-125b-5p, DACT1, and the JNK signaling-related factors in T2DM mice was determined. Finally, cell proliferation and apoptosis were determined. Mice with T2DM had lower pancreatic β-cell function and insulin sensitivity, as well as diminished expression of miR-125b-5p but enhanced expressions of DACT1, JNK and c-Jun. miR-125b-5p inhibited DACT1 expression and the activation of the JNK signaling pathway, as well as restrained cell proliferation and promoted cell apoptosis. The current results suggest that up-regulated miR-125b-5p promotes insulin sensitivity and enhances pancreatic β-cell function through inhibiting the JNK signaling pathway by negatively mediating DACT1.

Milk Powder Co-Supplemented with Inulin and Resistant Dextrin Improves Glycemic Control and Insulin Resistance in Elderly Type 2 Diabetes Mellitus: A 12-Week Randomized, Double-Blind, Placebo-Controlled Trial

SCOPE

The objective of the present study is to evaluate the effects of milk powder co-supplemented with inulin and resistant dextrin (MPCIR) on elderly patients with type 2 diabetes mellitus (T2DM).

METHODS AND RESULTS

A randomized, double-blind, placebo-controlled clinical trial is carried out among elderly T2DM patients. The subjects recruited from the community are randomly assigned to either the MPCIR group or placebo group for 12 weeks intervention. Each group receives 45 g milk powder with or without inulin and resistant dextrin. Anthropometric and metabolic variables are measured. For the MPCIR group, systolic blood pressure (BP) and diastolic BP are reduced significantly by 5.45 and 4.56 mm Hg (p < 0.001, vs placebo group), respectively. Compared with the placebo group, the fasting and 2-h postprandial plasma glucose levels, glycosylated serum protein, and insulin resistance index of the MPCIR group are significantly decreased by 0.96 mmol L^-1 , 1.47 mmol L^-1 , 16.33 μmol L^-1 , and 0.65 respectively (p < 0.001). The MPCIR group shows an increase by 7.09 μIU mL^-1 and 20.43 in 2-h postprandial insulin (p = 0.016) and β-cell function index (p < 0.001), respectively.

CONCLUSION

MPCIR supplementation helps to improve glycemic control, insulin resistance, and blood pressure.

Pokeweed antiviral protein attenuates liver fibrosis in mice through regulating Wnt/Jnk mediated glucose metabolism

BACKGROUND/AIMS

Pokeweed antiviral protein (PAP) has been reported to downregulate Wnt/Jnk pathway and attenuate liver fibrosis. This study was designed to intensively explore the mechanism of anti-fibrosis effect of PAP.

MATERIALS AND METHODS

Hepatic stellate cell (HSC) activation was induced by high concentration of glucose. Cell viability was detected at different time points after PAP treatment. Meanwhile, hepatic fibrosis models in mice were induced by CCl4 injection. In the end, liver pathology was observed and contents of alanine transaminase, aspartate transaminase, lactic dehydrogenase, hyaluronic acid (HA), and laminin (LN) in serum together with hydroxyproline (Hyp) in liver were measured. The mRNA and protein expressions of HK2, PFKP, PCK1, and FBP1 as well as Jnk expression in HSC-T6 cells and liver tissue were detected by qPCR and western-blot, respectively.

RESULTS

Compared with high glucose, PAP reduced viability and expressions of HK2, PFKP, α-SMA, and Col1A1, where as enhanced the expressions of PCK1 and FBP1 in HSC-T6 cells (P < 0.05) respectively. PAP attenuated liver pathology, improved liver function, and reduced collagen deposition in liver tissue compared with the model group (P < 0.05) respectively. Moreover, PAP reduced expressions of HK2, PFKP, α-SMA, and Col1A1 where as increased the expression of PCK1 and FBP1 in the liver of mice compared with the model group (P < 0.05) respectively. Most importantly, PAP reduced the phosphorylation of Jnk both in cells and liver tissue compared with the model group (P < 0.05) respectively.

CONCLUSIONS

Our results demonstrated that PAP attenuated liver fibrosis by regulating Wnt/Jnk-mediated glucose metabolism. It provided us a new target for the treatment of liver fibrosis.