Gelidium elegans Extract Ameliorates Type 2 Diabetes via Regulation of MAPK and PI3K/Akt Signaling

Pathophysiology of diabetic hepatopathy and molecular mechanisms underlying the hepatoprotective effects of phytochemicals

Patients with diabetes are at risk for liver disorders including glycogen hepatopathy, non-alcoholic fatty liver disease, cirrhosis, and hepatic fibrosis. The pathophysiological mechanisms behind diabetic hepatopathy are complex, some of them include fatty acid accumulation, increased reactive oxygen species, increased advanced glycation end-products, hyperactivity of polyol pathways, increased apoptosis and necrosis, and promotion of fibrosis. A growing number of studies have shown that herbal extracts and their active phytochemicals have antihyperglycemic properties and beneficial effects on diabetic complications. The current review, for the first time, focused on herbal agents that showed beneficial effects on diabetic hepatopathy. For example, animal studies have shown that Moringa oleifera and Morus alba improve liver function in both type-1 and type-2 diabetes. Also, evidence from clinical trials suggests that Boswellia serrata, Juglans regia, Melissa officinalis, Portulaca oleracea, Silybum marianum, Talapotaka Churna, and Urtica dioica reduce serum liver enzymes in diabetic patients. The main active ingredient of these plants to protect the liver seems to be phenolic compounds such as niazirin, chlorogenic acid, resveratrol, etc. Mechanisms responsible for the hepatoprotective activity of herbal agents include improving glucose metabolism, restoring adipokines levels, antioxidant defense, and anti-inflammatory activity. Several signaling pathways are involved in hepatoprotective effects of herbal agents in diabetes, such as phosphoinositide 3-kinase, adenosine monophosphate-activated protein kinase, mitogen-activated protein kinase, and c-Jun NH2-terminal kinase.

Algae-Derived Natural Products in Diabetes and Its Complications-Current Advances and Future Prospects

Diabetes poses a significant global health challenge, necessitating innovative therapeutic strategies. Natural products and their derivatives have emerged as promising candidates for diabetes management due to their diverse compositions and pharmacological effects. Algae, in particular, have garnered attention for their potential as a source of bioactive compounds with anti-diabetic properties. This review offers a comprehensive overview of algae-derived natural products for diabetes management, highlighting recent developments and future prospects. It underscores the pivotal role of natural products in diabetes care and delves into the diversity of algae, their bioactive constituents, and underlying mechanisms of efficacy. Noteworthy algal derivatives with substantial potential are briefly elucidated, along with their specific contributions to addressing distinct aspects of diabetes. The challenges and limitations inherent in utilizing algae for therapeutic interventions are examined, accompanied by strategic recommendations for optimizing their effectiveness. By addressing these considerations, this review aims to chart a course for future research in refining algae-based approaches. Leveraging the multifaceted pharmacological activities and chemical components of algae holds significant promise in the pursuit of novel antidiabetic treatments. Through continued research and the fine-tuning of algae-based interventions, the global diabetes burden could be mitigated, ultimately leading to enhanced patient outcomes.

Potential Mechanisms of Yiqi Jiedu Huayu Decoction in the Treatment of Diabetic Microvascular Complications Based on Network Analysis, Molecular Docking, and Experimental Validation

Background. Diabetic microvascular complications are the main causes of organ dysfunction and even death in diabetic patients. Our previous studies confirmed the beneficial effects of Yiqi Jiedu Huayu Decoction (YJHD) on diabetic cardiomyopathy and diabetic nephropathy. It is not clear whether YJHD can treat multiple diabetic microvascular complications including diabetic retinopathy, diabetic cardiomyopathy, and diabetic nephropathy through some common mechanisms. Methods. TCMSP, SymMap, STITCH, Swiss Target Prediction, and SEA databases were used to collect and analyze the components and targets of YJHD. GeneCards, DrugBank, DisGeNET, OMIM, and GEO databases were used to obtain target genes for diabetic retinopathy, diabetic cardiomyopathy, and diabetic nephropathy. The GO and KEGG enrichment analyses were performed on the DAVID and STRING platforms. Molecular docking was used to evaluate the binding sites and affinities of compounds and target proteins. Animal experiments were designed to validate the network pharmacology results. Results. Through network pharmacological analysis, oxidative stress, inflammatory response, and apoptosis were identified as key pathological phenotypes for the treatment of diabetic microvascular complications with YJHD. In addition, JNK, p38, and ERK1/2 were predicted as key targets of YJHD in regulating the abovementioned pathological phenotypes. The results of animal experiments showed that YJHD could ameliorate retinal pathological changes of diabetes rats. YJHD can inhibit oxidative stress and inflammation in heart and kidney of diabetic rats. Molecular docking showed strong binding between compounds and JNK, p38, and ERK1/2. Berlambine may play a key role in the treatment process and is considered as a promising regulator of MAPK protein family. The regulatory effects of YJHD on JNK, p38, and ERK1/2 were demonstrated in animal experiments. Conclusions. YJHD may play a therapeutic role in diabetic microvascular complications by regulating oxidative stress, inflammatory response, and apoptosis. The regulation of JNK, p38, and ERK1/2 phosphorylation may be the key to its therapeutic effect.

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.

Detecting the Critical States of Type 2 Diabetes Mellitus Based on Degree Matrix Network Entropy by Cross-Tissue Analysis

Type 2 diabetes mellitus (T2DM) is a metabolic disease caused by multiple etiologies, the development of which can be divided into three states: normal state, critical state/pre-disease state, and disease state. To avoid irreversible development, it is important to detect the early warning signals before the onset of T2DM. However, detecting critical states of complex diseases based on high-throughput and strongly noisy data remains a challenging task. In this study, we developed a new method, i.e., degree matrix network entropy (DMNE), to detect the critical states of T2DM based on a sample-specific network (SSN). By applying the method to the datasets of three different tissues for experiments involving T2DM in rats, the critical states were detected, and the dynamic network biomarkers (DNBs) were successfully identified. Specifically, for liver and muscle, the critical transitions occur at 4 and 16 weeks. For adipose, the critical transition is at 8 weeks. In addition, we found some "dark genes" that did not exhibit differential expression but displayed sensitivity in terms of their DMNE score, which is closely related to the progression of T2DM. The information uncovered in our study not only provides further evidence regarding the molecular mechanisms of T2DM but may also assist in the development of strategies to prevent this disease.

Exploring the plant-derived bioactive substances as antidiabetic agent: An extensive review

Diabetes mellitus (DM) is a metabolic syndrome. Diabetes has become more common in recent years. Chemically generated drugs are used to lessen the effects of DM and its following repercussions due to unpleasant side effects such as weight gain, gastrointestinal issues, and heart failure. On the other hand, medicinal plants could be a good source of anti-diabetic medications. This article aims to determine any plant matrix's positive potential. Food restriction, physical activity, and the use of antidiabetic plant-derived chemicals are all being promoted as effective ways to manage diabetes because they are less expensive and have fewer or no side effects. This review focuses on antidiabetic plants, along with their bioactive constituent, chemically characterization, and plant-based diets for diabetes management. There is minimal scientific data about the mechanism of action of the plant-based product has been found. The purpose of this article is to highlight anti-diabetic plants and plant-derived bioactive compounds that have anti-diabetic properties. It also provides researchers with data that may be used to build future strategies, such as identifying promising bioactive molecules to make diabetes management easier.

The Prospective Application of Melatonin in Treating Epigenetic Dysfunctional Diseases

In the past, different human disorders were described by scientists from the perspective of either environmental factors or just by genetically related mechanisms. The rise in epigenetic studies and its modifications, i.e., heritable alterations in gene expression without changes in DNA sequences, have now been confirmed in diseases. Modifications namely, DNA methylation, posttranslational histone modifications, and non-coding RNAs have led to a better understanding of the coaction between epigenetic alterations and human pathologies. Melatonin is a widely-produced indoleamine regulator molecule that influences numerous biological functions within many cell types. Concerning its broad spectrum of actions, melatonin should be investigated much more for its contribution to the upstream and downstream mechanistic regulation of epigenetic modifications in diseases. It is, therefore, necessary to fill the existing gaps concerning corresponding processes associated with melatonin with the physiological abnormalities brought by epigenetic modifications. This review outlines the findings on melatonin’s action on epigenetic regulation in human diseases including neurodegenerative diseases, diabetes, cancer, and cardiovascular diseases. It summarizes the ability of melatonin to act on molecules such as proteins and RNAs which affect the development and progression of diseases.

Seaweed Exhibits Therapeutic Properties against Chronic Diseases: An Overview

Seaweeds or marine macroalgae are known for producing potentially bioactive substances that exhibit a wide range of nutritional, therapeutic, and nutraceutical properties. These compounds can be applied to treat chronic diseases, such as cancer, cardiovascular disease, osteoporosis, neurodegenerative diseases, and diabetes mellitus. Several studies have shown that consumption of seaweeds in Asian countries, such as Japan and Korea, has been correlated with a lower incidence of chronic diseases. In this study, we conducted a review of published papers on seaweed consumption and chronic diseases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method for this study. We identified and screened research articles published between 2000 and 2021. We used PubMed and ScienceDirect databases and identified 107 articles. This systematic review discusses the potential use of bioactive compounds of seaweed to treat chronic diseases and identifies gaps where further research in this field is needed. In this review, the therapeutic and nutraceutical properties of seaweed for the treatment of chronic diseases such as neurodegenerative diseases, obesity, diabetes, cancer, liver disease, cardiovascular disease, osteoporosis, and arthritis were discussed. We concluded that further study on the identification of bioactive compounds of seaweed, and further study at a clinical level, are needed.

Combination Therapy with GABA and MgSO4 Improves Insulin Sensitivity in Type 2 Diabetic Rat

BACKGROUND

Gamma-aminobutyric acid (GABA) and magnesium sulfate (MgSO₄) play a crucial role in glycemic control. Therefore, we studied the effect of combination therapy with GABA and MgSO₄ to improve insulin sensitivity in diabetes induced by streptozotocin as well as high-fat diet in a diabetic rat model. Design and Methods. Forty randomly selected rats were assigned to four groups: nondiabetic control group was fed the normal diet, insulin-resistant diabetic rat model was induced by streptozotocin and high-fat diet, GABA + MgSO₄ group received GABA and MgSO₄, and insulin group was treated with insulin. Body weight, abdominal fat, blood glucose, serum insulin, and glucagon concentration were measured. The glucose clamp technique, glucose tolerance test, and insulin tolerance test were performed to study insulin sensitivity. Also, the expressions of glucose 6 phosphatase, glucagon receptor, and phosphoenolpyruvate carboxykinase genes in liver were assessed for the gluconeogenesis pathway. Protein translocation and glucose transporter 4 (Glut4) genes expression in muscle were also assessed.

RESULTS

Combination of GABA + MgSO₄ or insulin therapy enhanced insulin level, glycemic control, glucose and insulin tolerance test, some enzymes expression in the gluconeogenesis pathway, body fat, body weight, and glucagon receptor in diabetic rats. Moreover, an increase was observed in protein and gene expression of Glut4. Insulin sensitivity in combination therapy was more than the insulin group.

CONCLUSIONS

GABA and MgSO₄ enhanced insulin sensitivity via increasing Glut4 and reducing the gluconeogenesis enzyme and glucagon receptor gene expressions.

The effect and mechanism of Jiao-tai-wan in the treatment of diabetes mellitus with depression based on network pharmacology and experimental analysis

BACKGROUND

The incidence of diabetes mellitus (DM) and depression is increasing year by year around the world, bringing a serious burden to patients and their families. Jiao-tai-wan (JTW), a well-known traditional Chinese medicine (TCM), has been approved to have hypoglycemic and antidepressant effects, respectively, but whether JTW has such dual effects and its potential mechanisms is still unknown. This study is to evaluate the dual therapeutic effects of JTW on chronic restraint stress (CRS)-induced DM combined with depression mice, and to explore the underlying mechanisms through network pharmacology.

METHODS

CRS was used on db/db mice for 21 days to induce depression-like behaviors, so as to obtain the DM combined with depression mouse model. Mice were treated with 0.9% saline (0.1 ml/10 g), JTW (3.2 mg/kg) and Fluoxetine (2.0 mg/kg), respectively. The effect of JTW was accessed by measuring fasting blood glucose (FBG) levels, conducting behavioral tests and observing histopathological change. The ELISA assay was used to evaluate the levels of inflammatory cytokines and the UHPLC-MS/MS method was used to determine the depression-related neurotransmitters levels in serum. The mechanism exploration of JTW against DM and depression were performed via a network pharmacological method.

RESULTS

The results of blood glucose measurement showed that JTW has a therapeutic effect on db/db mice. Behavioral tests and the levels of depression-related neurotransmitters proved that JTW can effectively ameliorate depression-like symptoms in mice induced by CRS. In addition, JTW can also improve the inflammatory state and reduce the number of apoptotic cells in the hippocampus. According to network pharmacology, 28 active compounds and 484 corresponding targets of JTW, 1407 DM targets and 1842 depression targets were collected by screening the databases, and a total of 117 targets were obtained after taking the intersection. JTW plays a role in reducing blood glucose level and antidepressant mainly through active compounds such as quercetin, styrene, cinnamic acid, ethyl cinnamate, (R)-Canadine, palmatine and berberine, etc., the key targets of its therapeutic effect include INS, AKT1, IL-6, VEGF-A, TNF and so on, mainly involved in HIF-1 signal pathway, pathways in cancer, Hepatitis B, TNF signal pathway, PI3K-Akt signal pathway and MAPK signaling pathway, etc. CONCLUSION: Our experimental study showed that JTW has hypoglycemic and antidepressant effects. The possible mechanism was explored by network pharmacology, reflecting the characteristics of multi-component, multi-target and multi-pathway, which provides a theoretical basis for the experimental research and clinical application of JTW in the future.

The Antiproliferative and Apoptosis-Inducing Effects of the Red Macroalgae Gelidium latifolium Extract against Melanoma Cells

The red macroalga Gelidium latifolium is widely distributed in the coastal areas of Indonesia. However, current knowledge on its potential biological activities is still limited. In this study, we investigated the potential bioactive compounds in Gelidium latifolium ethanol extract (GLE), and its cytotoxic effects against the murine B16-F10 melanoma cell line. GLE shows high total phenolic content (107.06 ± 17.42 mg GAE/g) and total flavonoid content (151.77 ± 3.45 mg QE/g), which potentially contribute to its potential antioxidant activity (DPPH = 650.42 ± 2.01 µg/mL; ABTS = 557.01 ± 1.94 µg/mL). ESI-HR-TOF-MS analysis revealed large absorption in the [M-H]^- of 327.2339 m/z, corresponding to the monoisotopic molecular mass of brassicolene. The presence of this compound potentially contributes to GLE's cytotoxic activity (IC₅₀ = 84.29 ± 1.93 µg/mL). Furthermore, GLE significantly increased the number of apoptotic cells (66.83 ± 3.06%) compared to controls (18.83 ± 3.76%). Apoptosis was also confirmed by changes in the expression levels of apoptosis-related genes (i.e., p53, Bax, Bak, and Bcl2). Downregulated expression of Bcl2 indicates an intrinsic apoptotic pathway. Current results suggest that components of Gelidium latifolium should be further investigated as possible sources of novel antitumor drugs.

Characterization and Duodenal Transcriptome Analysis of Chinese Beef Cattle With Divergent Feed Efficiency Using RNA-Seq

Residual feed intake (RFI) is an important measure of feed efficiency for agricultural animals. Factors associated with cattle RFI include physiology, dietary factors, and the environment. However, a precise genetic mechanism underlying cattle RFI variations in duodenal tissue is currently unavailable. The present study aimed to identify the key genes and functional pathways contributing to variance in cattle RFI phenotypes using RNA sequencing (RNA-seq). Six bulls with extremely high or low RFIs were selected for detecting differentially expressed genes (DEGs) by RNA-seq, followed by conducting GO, KEGG enrichment, protein-protein interaction (PPI), and co-expression network (WGCNA, n = 10) analysis. A total of 380 differentially expressed genes was obtained from high and low RFI groups, including genes related to energy metabolism (ALDOA, HADHB, INPPL1), mitochondrial function (NDUFS1, RFN4, CUL1), and feed intake behavior (CCK). Two key sub-networks and 26 key genes were detected using GO analysis of DEGs and PPI analysis, such as TPM1 and TPM2, which are involved in mitochondrial pathways and protein synthesis. Through WGCNA, a gene network was built, and genes were sorted into 27 modules, among which the blue (r = 0.72, p = 0.03) and salmon modules (r = -0.87, p = 0.002) were most closely related with RFI. DEGs and genes from the main sub-networks and closely related modules were largely involved in metabolism; oxidative phosphorylation; glucagon, ribosome, and N-glycan biosynthesis, and the MAPK and PI3K-Akt signaling pathways. Through WGCNA, five key genes, including FN1 and TPM2, associated with the biological regulation of oxidative processes and skeletal muscle development were identified. Taken together, our data suggest that the duodenum has specific biological functions in regulating feed intake. Our findings provide broad-scale perspectives for identifying potential pathways and key genes involved in the regulation of feed efficiency in beef cattle.

Identification of biomarkers associated with metabolic cardiovascular disease using mRNA-SNP-miRNA regulatory network analysis

Background

CVD is the leading cause of death in T2DM patients. However, few biomarkers have been identified to detect and diagnose CVD in the early stage of T2DM. The aim of our study was to identify the important mRNAs, micro (mi)RNAs and SNPs (single nucleotide polymorphisms) that are associated with metabolic cardiovascular disease.

Materials and methods

Expression profiles and GWAS data were obtained from Gene Expression Omnibus (GEO) database. MiRNA-sequencing was conducted by Illumina HiSeq 2000 platform in T2DM patients and T2DM with CVD patients. EQTL analysis and gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted. MRNA-miRNA co-expression network and mRNA-SNP-miRNA interaction network were established and visualized by Cytoscape 3.7.2.

Results

In our study, we identified 56 genes and 16 miRNAs that were significantly differentially expressed. KEGG analyses results indicated that B cell receptor signaling pathway and hematopoietic cell lineage were included in the biological functions of differentially expressed genes. MRNA-miRNA co-expression network and mRNA-SNP-miRNA interaction network illustrated that let-7i-5p, RASGRP3, KRT1 and CEP41 may be potential biomarkers for the early detection and diagnosis of CVD in T2DM patients.

Conclusion

Our results suggested that downregulated let-7i-5p, and upregulated RASGRP3, KRT1 and CEP41 may play crucial roles in molecular mechanisms underlying the initiation and development of CVD in T2DM patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02166-4.

Ursolic acid induces white adipose tissue beiging in high-fat-diet obese male mice

Ursolic acid (UA) shows an effect on obesity and related metabolic diseases, but its mechanism of action remains unclear. We found that UA clearly reduced the body weight and adipose tissue mass and improved the glucose tolerance and insulin sensitivity in obese male mice. UA treatment significantly reduced the volume and weights of the epididymal white adipose tissue (eWAT) and inguinal subcutaneous white adipose tissue (igSWAT) of HFD-fed mice, respectively. UA also decreased the expression of genes involved in adipocyte differentiation and lipogenesis in igSWAT. Real-time PCR and immunohistochemistry showed that the expression of beiging-related genes 4-1BB factor (CD137), T-box transcription factor 1 (TBX1), and transmembrane protein 26 (TMEM26) were significantly increased in the UA treatment group. UA treatment significantly reduced the weight of gastrocnemius muscle (GM) and lipid droplets in the GM. UA treatment significantly upregulated the expression of PR domain-containing 16 (PRDM16), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), and fibronectin type 3 domain-containing protein 5 (FNDC5) in GM and igSWAT. UA also stimulated irisin secretion in the serum. In conclusion, these results indicate that UA plays an anti-obesogenic role by increasing the secretion of irisin and promoting the beiging of WAT.

Plants Secondary Metabolites as Blood Glucose-Lowering Molecules

Recently, significant advances in modern medicine and therapeutic agents have been achieved. However, the search for effective antidiabetic drugs is continuous and challenging. Over the past decades, there has been an increasing body of literature related to the effects of secondary metabolites from botanical sources on diabetes. Plants-derived metabolites including alkaloids, phenols, anthocyanins, flavonoids, stilbenoids, saponins, tannins, polysaccharides, coumarins, and terpenes can target cellular and molecular mechanisms involved in carbohydrate metabolism. In addition, they can grant protection to pancreatic beta cells from damage, repairing abnormal insulin signaling, minimizing oxidative stress and inflammation, activating AMP-activated protein kinase (AMPK), and inhibiting carbohydrate digestion and absorption. Studies have highlighted many bioactive naturally occurring plants' secondary metabolites as candidates against diabetes. This review summarizes the current knowledge compiled from the latest studies published during the past decade on the mechanism-based action of plants-derived secondary metabolites that can target various metabolic pathways in humans against diabetes. It is worth mentioning that the compiled data in this review will provide a guide for researchers in the field, to develop candidates into environment-friendly effective, yet safe antidiabetics.

The Effect of Coffee Arabica Gayo Leaf Extract (Coffea arabica L.) on Increased PI3K Serum Levels in Type 2 Diabetic Rat

BACKGROUND: Coffee arabica gayo leaf extract (Coffea arabica L.) contains polyphenols (chlorogenic acid), flavonoids, saponins, tannins, and steroids which improved PI3K serum levels in rats type 2 diabetic rat. AIM: The purpose of the study was to determine the effect of Coffee Arabica Gayo Leaf Extract (C. arabica L.) on increased PI3K serum levels in type-2 diabetic rat (Rattus norvegicus). METHODS: Thirty-five male Wistar rats with type 2 diabetic induced a combination of feeding a high-fat diet for 5 weeks and intraperitoneal injection of low dose streptozotocin (30 mg/kg). The diabetic rats were randomly divided into seven groups which consist of group without type 2 diabetic, group without type 2 diabetic with dose 250 mg/kg/day Coffee Arabica Gayo Leaf Extract, group with type 2 diabetic without intervention, group with type 2 diabetic with metformin, and group with type 2 diabetic with Coffee Arabica Gayo Leaf Extract doses 150, 200, and 250 mg/kg/day. The extract was administered orally for 30 days. Subsequently, PI3K serum levels were measure by Sandwich Elisa. RESULTS: There were significantly higher PI3K serum levels in the treatment groups than in the control groups (p = 0.037) after giving Coffee Arabica Gayo Leaf Extract 200 mg/kg/day and 250 mg/kg/day to rats for 30 days. CONCLUSION: These data suggest that Coffee Arabica Gayo Leaf Extract can improve PI3K serum levels in a rat model type 2 diabetic.

A Comprehensive miRNome Analysis of Macrophages Isolated from db/db Mice and Selected miRNAs Involved in Metabolic Syndrome-Associated Cardiac Remodeling

Cardiac macrophages are known from various activities, therefore we presume that microRNAs (miRNAs) produced or released by macrophages in cardiac tissue have impact on myocardial remodeling in individuals with metabolic syndrome (MetS). We aim to assess the cardiac macrophage miRNA profile by selecting those miRNA molecules that potentially exhibit regulatory functions in MetS-related cardiac remodeling. Cardiac tissue macrophages from control and db/db mice (an animal model of MetS) were counted and sorted with flow cytometry, which yielded two populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Total RNA was then isolated, and miRNA expression profiles were evaluated with Next Generation Sequencing. We successfully sequenced 1400 miRNAs in both macrophage populations: CD45+CD11b+CD64+Ly6Chi and CD45+CD11b+CD64+Ly6Clow. Among the 1400 miRNAs, about 150 showed different expression levels in control and db/db mice and between these two subpopulations. At least 15 miRNAs are possibly associated with MetS pathology in cardiac tissue due to direct or indirect regulation of the expression of miRNAs for proteins involved in angiogenesis, fibrosis, or inflammation. In this paper, for the first time we describe the miRNA transcription profile in two distinct macrophage populations in MetS-affected cardiac tissue. Although the results are preliminary, the presented data provide a foundation for further studies on intercellular cross-talk/molecular mechanism(s) involved in the regulation of MetS-related cardiac remodeling.

COL1A1 as a potential new biomarker and therapeutic target for type 2 diabetes

Type 2 diabetes (T2D) is a public health problem with a rising incidence worldwide. In this study, a potential new biomarker for T2D and mechanisms underlying the hypoglycemic effects of Enteromorpha prolifera oligosaccharide were investigated. Tandem mass tag labeling with LC-MS/MS was used to identify the differentially expressed proteins (DEPs) between the jejunum of diabetic rats and control rats. Correlations between glycometabolic parameters and DEPs were revealed by a network analysis. The expression levels of target genes in key metabolic pathways were further evaluated to identify candidate biomarkers. Among 6810 total proteins, approximately 88 % were quantified, of which 148 DEPs with a fold change of <0.83 or>1.2 and a corrected p-value of <0.05 were identified. A KEGG enrichment analysis indicated that the hypoglycaemic effects of E. prolifera oligosaccharide involved the PI3K/AKT and extracellular matrix receptor interaction signaling pathways. More importantly, Col1a1 was the most significant gene in the extracellular matrix receptor interaction pathway and was linked to hypoglycaemic activity for the first time. Thus, Col1a1 is a novel potential therapeutic target for alleviating T2D.

FoxO1 signaling as a therapeutic target for type 2 diabetes and obesity

Glucose production and the consumption of high levels of carbohydrate increase the chance of insulin resistance, especially in cases of obesity. Therefore, maintaining a balanced glucose homeostasis might form a strategy to prevent or cure diabetes and obesity. The activation and inhibition of glucose production is complicated due to the presence of many interfering pathways. These pathways can be viewed at the downstream level because they activate certain transcription factors, which include the Forkhead-O1 (FoxO1). This has been identified as a significant agent in the pancreas, liver, and adipose tissue, which is significant in the regulation of lipids and glucose. The objective of this review is to discuss the intersecting portrayal of FoxO1 and its parallel cross-talk which highlights obesity-induced insulin susceptibility in the discovery of a targeted remedy. The review also analyses current progress and provides a blueprint on therapeutics, small molecules, and extracts/phytochemicals which are explored at the pre-clinical level.

Insulin-Like Proteins in Plant Sources: A Systematic Review

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia. Proteins in plant sources that enable the maintenance of the glycemic profile may be of interest in the context of T2DM. However, their mechanisms of action are unclear, unlike other bioactive compounds. This systematic review identified and described the mechanisms of action of isolated and purified proteins and peptides extracted from vegetables on the reduction of blood glucose in T2DM in experimental studies. The research was done in PubMed, ScienceDirect, Scopus, Web of Science, Embase and Virtual Health Library (VHL) databases in March 2019. The initial search retrieved 916 articles, and, after reading the title, abstract and keywords, 24 articles were eligible for full reading. Then, five articles were eligible to build this systematic review. The evaluation of the evidence and the strength of the recommendations of the studies was evaluated with the SYstematic Review Center for Laboratory animal Experimentation - SYRCLE. Studies with proteins or peptides extracted from soybean (Glycine max), corn (Zea mays), peas (Pisum sativum), costus (Costus igneus) and ginseng (Panax ginseng) were found, and all of them decreased glycemia but not by the same mechanisms. The mechanism of action of proteins extracted from Glycine max, Pisum sativum, Costus igneus were similar, acting in the insulin-mediated pathways. The peptide derived from Zea mays increased GLP-1 expression, and the peptide from Panax ginseng reduced NF-kB signaling, both resulting in stimulating the release of insulin. Therefore, bioactive proteins and peptides of plant sources act through biochemical pathways, in the modulation of insulin resistance and the hyperglycemic state. These compounds are promising in scientific research on T2DM, because there is a probable similarity of these proteins with insulin, which enables them to act as insulin-like molecules.

Investigating the Mechanistic Differences of Obesity-Inducing Lactobacillus kefiranofaciens M1 and Anti-obesity Lactobacillus mali APS1 by Microbolomics and Metabolomics

Many studies have investigated the anti-obesity effects of probiotics in animal models and humans. However, few studies have focused on the mechanisms of obesity-inducing probiotics. In a previous study, we demonstrated that specific bacterial strains isolated from kefir, Lactobacillus kefirnofaciens M1 and Lactobacillus mali APS1, possess obesity and anti-obesity effects, respectively, in high-fat diet (HFD)-induced obese mice. Thus, in the present study, we systematically investigated whether APS1 and M1 affect energy homeostasis and lipid metabolism in HFD-induced obese mice and how this might be achieved. We observed that the M1/APS1 intervention influenced fat accumulation by regulating adipogenesis and inflammation-related marker expression both in vitro and in a HFD induced C57BL/6J mice model. We also observed putative links between key taxa and possible metabolic processes of the gut microbiota. Notably, families Christensenellaceae and S24_7 were negatively correlated with body weight gain through increase in the essential esterized carnitine for energy expenditure. These results suggest the importance of specific probiotic interventions affecting leanness and obesity of subjects under a HFD, which are operated by modulating the tripartite relationship among the host, microbiota, and metabolites.

Supplementation with Sea Vegetables Palmaria mollis and Undaria pinnatifida Exerts Metabolic Benefits in Diet-Induced Obesity in Mice

BACKGROUND

Sea vegetables are rich sources of nutrients as well as bioactive components that are linked to metabolic health improvement. Algal polysaccharides improve satiety and modulate gut microbiota while proteins, peptides, and phenolic fractions exert anti-inflammatory, antioxidant, and antidiabetic effects.

OBJECTIVE

We tested the hypothesis that dietary supplementation with either Pacific dulse (Palmaria mollis, red algae) or wakame (Undaria pinnatifida, brown algae) could remediate metabolic complications in high-fat diet-induced obesity.

METHODS

Individually caged C57BL/6J mice (n = 8) were fed ad libitum with either a low-fat diet (LFD), 10% kcal fat; high-fat diet (HFD), 60% kcal fat; HFD + 5% (wt:wt) dulse (HFD + D); or HFD + 5% (wt:wt) wakame (HFD + W) for 8 weeks. Food intake and weight gain were monitored weekly. Glucose tolerance, hepatic lipids, fecal lipids, and plasma markers were evaluated, and the gut microbiome composition was assessed.

RESULTS

Despite the tendency of higher food and caloric intake than the HFD (P = 0.04) group, the HFD + D group mice did not exhibit higher body weight, indicating lower food and caloric efficiency (P < 0.001). Sea vegetable supplementation reduced plasma monocyte chemotactic protein (MCP-1) (P < 0.001) and increased fecal lipid excretion (P < 0.001). Gut microbiome analysis showed that the HFD + D group had higher alpha-diversity than the HFD or LFD group, whereas beta-diversity analyses indicated that sea vegetable-supplemented HFD-fed mice (HFD + D and HFD + W groups) developed microbiome compositions more similar to those of the LFD-fed mice than those of the HFD-fed mice.

CONCLUSION

Sea vegetable supplementation showed protective effects against obesity-associated metabolic complications in C57BL/6J male mice by increasing lipid excretion, reducing systemic inflammatory marker, and mitigating gut microbiome alteration. While the obese phenotype development was not prevented, metabolic issues related to lipid absorption, inflammation, and gut microbial balance were improved, showing therapeutic promise and warranting eventual mechanistic elucidations.

Reduction of blood glucose by plant extracts and their use in the treatment of diabetes mellitus; discrepancies in effectiveness between animal and human studies

ETHNOPHARMACOLOGICAL RELEVANCE

The global problem of diabetes, together with the limited access of large numbers of patients to conventional antidiabetic medicines, continues to drive the search for new agents. Ancient Asian systems such as traditional Chinese medicine, Japanese Kampo medicine, and Indian Ayurvedic medicine, as well as African traditional medicine and many others have identified numerous plants reported anecdotally to treat diabetes; there are probably more than 800 such plants for which there is scientific evidence for their activity, mostly from studies using various models of diabetes in experimental animals.

AIM OF THE REVIEW

Rather than a comprehensive coverage of the literature, this article aims to identify discrepancies between findings in animal and human studies, and to highlight some of the problems in developing plant extract-based medicines that lower blood glucose in patients with diabetes, as well as to suggest potential ways forward.

METHODS

In addition to searching the 2018 PubMed literature using the terms 'extract AND blood glucose, a search of the whole literature was conducted using the terms 'plant extracts' AND 'blood glucose' AND 'diabetes' AND 'double blind' with 'clinical trials' as a filter. A third search using PubMed and Medline was undertaken for systematic reviews and meta-analyses investigating the effects of plant extracts on blood glucose/glycosylated haemoglobin in patients with relevant metabolic pathologies.

FINDINGS

Despite numerous animal studies demonstrating the effects of plant extracts on blood glucose, few randomised, double-blind, placebo-controlled trials have been conducted to confirm efficacy in treating humans with diabetes; there have been only a small number of systematic reviews with meta-analyses of clinical studies. Qualitative and quantitative discrepancies between animal and human clinical studies in some cases were marked; the factors contributing to this included variations in the products among different studies, the doses used, differences between animal models and the human disease, and the impact of concomitant therapy in patients, as well as differences in the duration of treatment, and the fact that treatment in animals may begin before or very soon after the induction of diabetes.

CONCLUSION

The potential afforded by natural products has not yet been realised in the context of treating diabetes mellitus. A systematic, coordinated, international effort is required to achieve the goal of providing anti-diabetic treatments derived from medicinal plants.

Mechanism of the action of bioactive proteins of vegetables in diabetes mellitus type 2: Systematic review protocol

BACKGROUND

Diabetes mellitus type 2 (DM2) is a chronic disease of significant prevalence causing hyperglycemia and several comorbidities. Evidences highlight the performance of non - protein bioactive compounds found in vegetables in the control of hyperglycemia. This study describes a protocol of a systematic review, which analyzes the action of proteins and bioactive peptides of plants in DM2.

METHODS

The Preferred Reporting Items guide this protocol for Systematic Reviews and Meta-Analyzes Protocols (PRISMA-P) was used. The databases that will be used for searching will be PubMed, ScienceDirect, Scopus, Web of Science, EMBASE, and Virtual Health Library, Brazil (VHL). Studies that use bioactive proteins and peptides of vegetal origin in DM2 will be included in the systematic review. The studies will be identified using clinical parameters and the effect on insulin resistance. The characteristics of the studies as control groups, test substance, dosage, intervention time, and the main results will be described. Selection of studies, data extraction, and methodological quality assessment will be performed independently by two experienced reviewers.

RESULTS

This protocol will be the basis for a systematic review identifying the mechanism of action of plant proteins and peptides in type 2 diabetes mellitus.

CONCLUSION

Systematic reviews from this protocol will provide support for the construction of researches that analyze the effect of plant bioactive proteins and peptides on the control of hyperglycemia and how these molecules act in the control of DM2.

PROSPERO REGISTRATION NUMBER

CRD42019110956.

Ethanol-Induced Hepatic Insulin Resistance is Ameliorated by Methyl Ferulic Acid Through the PI3K/AKT Signaling Pathway

One of the key events during the development of alcoholic liver disease (ALD) is that alcohol inhibits the insulin signaling pathway in liver and leads to disorders of glucose and lipid metabolism. Methyl ferulic acid (MFA) is a biologically active monomer isolated from the root of Securidaca inappendiculata Hasskarl. It has been reported that MFA has a hepatoprotective effect against alcohol-induced liver injury in vivo and in vitro. However, the effect of MFA on ethanol-induced insulin resistance in ALD remains unclear. In this study, we investigated whether MFA could exert protective effects against hepatic insulin resistance in ethanol-induced L-02 cells and ALD rats. ALD was induced in vivo by feeding Lieber-DeCarli diet containing 5% (w/v) alcohol for 16 weeks to Sprague-Dawley rats. Insulin resistance was induced in vitro in human hepatocyte L-02 cells with 200 mM ethanol for 24 h followed by 10-7 nM insulin for 30 min. MFA exhibited the effects of inhibited insulin resistance, reduced enzymatic capacity for hepatic gluconeogenesis, and increased hepatic glycogen synthesis both in vivo and in vitro. In addition, the results of transcriptome sequencing of liver tissues in the ethanol- and MFA-treated groups indicated that "pyruvate metabolism," "glycolysis/gluconeogenesis," and "fatty acid metabolism" were significantly different between ethanol- and MFA-treated groups. Further studies suggested that MFA activated the hepatic phosphatidylinositol 3-kinase (PI3K)/AKT pathway in vivo and in vitro. Taken together, these findings suggested that MFA effectively ameliorated hepatic insulin resistance in ALD at least partially by acting on the PI3K/AKT pathway.

To Explore the Pathogenesis of Vascular Lesion of Type 2 Diabetes Mellitus Based on the PI3K/Akt Signaling Pathway

BACKGROUND

Type 2 diabetes mellitus (T2DM) has become a chronic disease, serious harm to human health. Complications of the blood pipe are the main cause of disability and death in diabetic patients, including vascular lesions that directly affects the prognosis of patients with diabetes and survival. This study was to determine the influence of high glucose and related mechanism of vascular lesion of type 2 diabetes mellitus pathogenesis.

METHODS

In vivo aorta abdominalis of GK rats was observed with blood pressure, heart rate, hematoxylin and eosin (H&E), Masson, and Verhoeff staining. In vitro cells were cultured with 30 mM glucose for 24 h. RT-QPCR was used to detect the mRNA expression of endothelial markers PTEN, PI3K, Akt, and VEGF. Immunofluorescence staining was used to detect the expression of PTEN, PI3K, Akt, and VEGF. PI3K and Akt phosphorylation levels were detected by Western blot analysis.

RESULTS

Heart rate, systolic blood pressure, diastolic blood pressure, and mean blood pressure in the GK control group were higher compared with the Wistar control group and no difference compared with the GK experimental model group. Fluorescence intensity of VEGF, Akt, and PI3K in the high-sugar stimulus group was stronger than the control group; PTEN in the high-sugar stimulus group was weakening than the control group. VEGF, Akt, and PI3K mRNA in the high-sugar stimulus group were higher than the control group; protein expressions of VEGF, Akt, and PI3K in the high-sugar stimulus group were higher than the control group. PTEN mRNA in the high-sugar stimulus group was lower than the control group. Protein expression of PTEN in the high-sugar stimulus group was lower than the control group.

CONCLUSIONS

Angiogenesis is an important pathogenesis of T2DM vascular disease, and PTEN plays a negative regulatory role in the development of new blood vessels and can inhibit the PI3K/Akt signaling pathway.

Ethanolic Extract of Folium Sennae Mediates the Glucose Uptake of L6 Cells by GLUT4 and Ca2

In today’s world, diabetes mellitus (DM) is on the rise, especially type 2 diabetes mellitus (T2DM), which is characterized by insulin resistance. T2DM has high morbidity, and therapies with natural products have attracted much attention in the recent past. In this paper, we aimed to study the hypoglycemic effect and the mechanism of an ethanolic extract of Folium Sennae (FSE) on L6 cells. The glucose uptake of L6 cells was investigated using a glucose assay kit. We studied glucose transporter 4 (GLUT4) expression and AMP-activated protein kinase (AMPK), protein kinase B (PKB/Akt), and protein kinase C (PKC) phosphorylation levels using western blot analysis. GLUT4 trafficking and intracellular Ca²⁺ levels were monitored by laser confocal microscopy in L6 cells stably expressing IRAP-mOrange. GLUT4 fusion with plasma membrane (PM) was observed by myc-GLUT4-mOrange. FSE stimulated glucose uptake; GLUT4 expression and translocation; PM fusion; intracellular Ca²⁺ elevation; and the phosphorylation of AMPK, Akt, and PKC in L6 cells. GLUT4 translocation was weakened by the AMPK inhibitor compound C, PI3K inhibitor Wortmannin, PKC inhibitor Gö6983, G protein inhibitor PTX/Gallein, and PLC inhibitor U73122. Similarly, in addition to PTX/Gallein and U73122, the IP3R inhibitor 2-APB and a 0 mM Ca²⁺-EGTA solution partially inhibited the elevation of intracellular Ca²⁺ levels. BAPTA-AM had a significant inhibitory effect on FSE-mediated GLUT4 activities. In summary, FSE regulates GLUT4 expression and translocation by activating the AMPK, PI3K/Akt, and G protein–PLC–PKC pathways. FSE causes increasing Ca²⁺ concentration to complete the fusion of GLUT4 vesicles with PM, allowing glucose uptake. Therefore, FSE may be a potential drug for improving T2DM.

Preventative effects of resveratrol and estradiol on streptozotocin-induced diabetes in ovariectomized mice and the related mechanisms

Resveratrol, a non-flavonoid polyphenolic compound, is structurally and functionally similar to estrogen and has drawn great attention for its potentially beneficial effects on diabetes. However, it is not known whether it shares the same protective effect against diabetes as estrogen and the underlying mechanisms. The aim of the present study was to investigate the protective effects of phytoestrogen resveratrol and exogenous 17β-estradiol against streptozotocin (STZ)-induced type 1 diabetes. Female mice were ovariectomized (OVX) and chronically injected with different concentrations of resveratrol (0.1, 1 or 10 mg/kg) and 17β-estradiol (0.01, 0.1 or 1 mg/kg) subcutaneously for 4 weeks, and the levels of blood glucose, plasma insulin, plasma antioxidant capacity, the changes of pancreatic islet cells and the expressions of glucose transporter 4 (GLUT4), insulin receptor substrate 1 (IRS-1) and phosphorylation of extracellular signal-regulated kinase (p-ERK) were detected. Resveratrol and 17β-estradiol significantly inhibited the increase of the blood glucose level and the rise of plasma malondialdehyde in STZ-induced diabetic mice, improved the levels of plasma antioxidant capacity and plasma insulin, protected the pancreatic islet cells, and increased the expressions of GLUT4 and IRS-1, but decreased p-ERK expression in skeletal muscle and myocardial tissue. The results suggest that resveratrol or 17β-estradiol shows obvious protection against STZ-induced diabetes in OVX mice, the mechanisms probably involve their ameliorating antioxidant activities and islet function, promoting muscle glucose uptake and inhibiting the expression of p-ERK.

Effect of Red Ginseng Extract on the Pharmacokinetics and Efficacy of Metformin in Streptozotocin-Induced Diabetic Rats

The purpose of this study was to investigate the effect of red ginseng extract on the pharmacokinetics (PK) and efficacy of metformin in streptozotocin-induced diabetic rats. The diabetes mellitus rat model was established by intraperitoneally administering multiple doses of streptozotocin (30 mg/kg, twice on day 1 and 8), and diabetic rats received metformin 50 mg/kg with or without single or multiple administration of Korean red ginseng extract (RGE, 2 g/kg/day, once or for 1 week). RGE administration did not affect the plasma concentration and renal excretion of metformin. Further, diabetic rats were administered metformin (50 mg/kg) and RGE (2 g/kg) alone or concomitantly for 5 weeks, and both regimens decreased the fasting blood glucose and glycated hemoglobin (Hb-A1c) levels. Furthermore, fasting blood glucose levels were reduced by metformin or RGE administered alone but recovered to the control level following co-administration, suggesting that the effect was additive. However, triglyceride and free fatty acid levels were not different with metformin and RGE treatment alone or in combination. Biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol levels were not different among the three treatment groups. In conclusion, RGE and metformin showed an additive effect in glycemic control. However, the co-administration of RGE and metformin did not cause PK interactions or affect biochemical parameters including the free fatty acid, triglyceride, AST, ALT, or cholesterol levels.

Single, 14-Day, and 13-Week Repeated Dose Toxicity Studies of Daily Oral Gelidium elegans Extract Administration to Rats

Gelidium elegans extract (GEE) is derived from a red alga from the Asia-Pacific region, which has antioxidant, anti-adipogenic, and anti-hyperglycemic effects. However, detailed studies of the toxicology of GEE have not been performed. We evaluated the single oral dose toxicity of GEE in male and female Sprague-Dawley (CD) rats. GEE did not cause deaths or have toxic effects at dosages of 5000 mg/kg/day, although compound-colored stools and diarrhea were observed in both sexes, which lasted <2 days. Therefore, the LD50 of GEE is likely to be >5000 mg/kg. We next evaluated the repeated oral dose toxicity of GEE in CD rats over 14 days and 13 weeks. GEE did not induce any significant toxicological changes in either sex at 2000 mg/kg/day. Repeated oral dose toxicity studies showed no adverse effects, in terms of clinical signs, mortality, body mass, food consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy, organ masses, or histopathology, at dosages of 500, 1000, or 2000 mg/kg/day. The no observed adverse effect level (NOAEL) for GEE is thus likely to be >2000 mg/kg/day, and no pathology was identified in potential target organs. Therefore, this study indicates that repeated oral dosing with GEE is safe in CD rats.