Clinical Review of Antidiabetic Drugs: Implications for Type 2 Diabetes Mellitus Management

Recently isolated antidiabetic hydrolysates and peptides from multiple food sources: a review

Diabetes, a metabolic syndrome of global importance has been on a progressive rise in recent years. Several pharmacological approaches have been made, which have proved effective, but with underlying side effects. Bioactive hydrolysates (BHs) and peptides (BPs) from food sources, however, have shown the relative advantage of imparting less adverse effects. Furthermore, BHs and BPs from food have been discovered to impart their antidiabetic potentials through one or more mechanisms such as inhibition of digestive enzymes, inhibition of the antigenic enzyme - Dipeptyl peptidase IV (DPP-IV), decrease in blood glucose levels and increase in insulin uptake. Several plants and animal sources have been used as protein sources for the isolation of antidiabetic hydrolysates and peptides through different mechanisms and analytical techniques. This review integrates recent research information about several popular and unconventional food sources of BHs and BPs, their isolation techniques, antidiabetic effects and protein profiles. In addition, the fractionation technique(s) employed in each study and inhibition potentials of BHs and BPs are reviewed. This article is intended to supplement accessible scholarly literature and intellectual awareness on the subject of food-oriented approach for the management of diabetes.

The effect of individual and mixed rewards on diabetes management: A feasibility randomized controlled trial

Background: Incentives play a role in introducing health-related benefits, but no interventions using mixed incentives, i.e. a combination of individual and group incentives, have been tested in individuals with type 2 diabetes mellitus (T2DM). We evaluated the feasibility of implementing individual- and mixed-incentives, with and without a supportive partner, on glycated haemoglobin (HbA1c) control and weight loss among patients with T2DM. Methods: This is a feasibility, sex-stratified, single-blinded, randomized controlled study in individuals with T2DM. All participants received diabetes education and tailored goal setting for weight and glycated haemoglobin (HbA1c). Participants were randomly assigned into three arms: individual incentives (Arm 1), mixed incentives-altruism (Arm 2), and mixed incentives-cooperation (Arm 3). Participants were accompanied by a diabetes educator every other week to monitor targets, and the intervention period lasted 3 months. The primary outcome was the change in HbA1c at 3 months from baseline. Weight and change body mass index (BMI) were considered as secondary outcomes. Results: Out of 783 patients screened, a total of 54 participants, 18 per study arm, were enrolled and 44 (82%) completed the 3-month follow-up. Mean baseline HbA1c values were 8.5%, 7.9% and 8.2% in Arm 1, Arm 2, and Arm 3, respectively. At 3 months, participants in all three study arms showed reductions in HbA1c ranging from -0.9% in Arm 2 to -1.4% in Arm 1. Weight and BMI also showed reductions. Conclusions: Individual and mixed cash incentives show important reductions in HbA1c, weight and BMI in patients with type 2 diabetes mellitus after 3 months.  Recruitment and uptake of the intervention were successfully accomplished demonstrating feasibility to conduct larger effectiveness studies to test individual and mixed economic incentives for diabetes management. Registration: ClinicalTrials.gov Identifier NCT02891382.

The Unprecedented Role of Gold Nanomaterial in Diabetes Management

Gold nanoparticles possess unique mechanical, chemical, photo-optical and biological properties and have been an interesting field of research on life sciences. The research studies produced new nanodevices and nanotechnology-based biosensing, diagnostics therapeutics, and targeted drug delivery systems. In this review, the unique potential aspects of gold nanoparticles/ nanoformulations/ or devices related to diabetes management have been discussed together with the recent patent on the gold nanoparticles developed for diabetes management. The first part of this review will focus on recent strategies for the treatment of hyperglycemia and its management with the help of gold nanoparticles and the second part of the review focused on recent patents on gold nanoparticles useful in the diabetes management. Gold nanoparticles have proved themselves useful in diabetes therapeutics and diagnostics. Due to the high surface area, and low toxicity, gold nanoparticles have become a unique aspect of the delivery approach. The main issues that need to be covered are the biopharmaceutics, biocompatibility, and potential clinical applications.

Food-Derived Bioactive Peptides in Human Health: Challenges and Opportunities

Recent scientific evidence suggests that food proteins not only serve as nutrients, but can also modulate the body's physiological functions. These physiological functions are primarily regulated by some peptides that are encrypted in the native protein sequences. These bioactive peptides can exert health beneficial properties and thus are considered as a lead compound for the development of nutraceuticals or functional foods. In the past few decades, a wide range of food-derived bioactive peptide sequences have been identified, with multiple health beneficial activities. However, the commercial application of these bioactive peptides has been delayed because of the absence of appropriate and scalable production methods, proper exploration of the mechanisms of action, high gastro-intestinal digestibility, variable absorption rate, and the lack of well-designed clinical trials to provide the substantial evidence for potential health claims. This review article discusses the current techniques, challenges of the current bioactive peptide production techniques, the oral use and gastrointestinal bioavailability of these food-derived bioactive peptides, and the overall regulatory environment.

Occurrence, Impact, Analysis and Treatment of Metformin and Guanylurea in Coastal Aquatic Environments of Canada, USA and Europe

This review discusses the occurrence, impact, analysis and treatment of metformin and guanylurea in coastal aquatic environments of Canada, USA and Europe. Metformin, a biguanide in chemical classification, is widely used as one of the most effective first-line oral drugs for type 2 diabetes. It is difficult to be metabolized by the human body and exists in both urine and faeces samples in these regions. Guanylurea is metformin's biotransformation product. Consequently, significant concentrations of metformin and guanylurea have been reported in wastewater treatment plants (WWTPs) and coastal aquatic environments. The maximum concentrations of metformin and guanylurea in surface water samples were as high as 59,000 and 4502ngL^-1, respectively. Metformin can be absorbed in non-target organisms by plants and in Atlantic salmon (Salmo salar). Guanylurea has a confirmed mitotic activity in plant cells. Analysis methods of metformin are currently developed based on high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The removal of metformin from aquatic environments in the target regions is summarized. The review helps to fill a knowledge gap and provides insights for regulatory considerations. The potential options for managing these emerging pollutants are outlined too.

Glucose-Lowering Therapies for Cardiovascular Risk Reduction in Type 2 Diabetes Mellitus: State-of-the-Art Review

Type 2 diabetes mellitus (T2DM) is a major cardiovascular (CV) risk factor. Although antihyperglycemic therapies have typically focused on glycemic control, a paradigm shift for the treatment of T2DM has occurred, with an increased focus on CV risk reduction. Clinicians should base their clinical decisions on the beneficial effects of specific glucose-lowering agents on CV outcomes, while avoiding those therapeutic strategies with potential detrimental effects. Importantly, the presence of comorbidities (eg, established cardiovascular diseases, hypertension, obesity) should also guide the clinical decision toward therapies proven to reduce CV outcomes in that specific population. In this state-of-the-art review resulting from a comprehensive literature search (Pubmed, Google Scholar), we summarize the evidence related to the CV outcomes trials reported in the past several decades. Finally, we propose a therapeutic plan for patients with T2DM, suggesting the use of specific glucose-lowering agents based on the characteristics and presence of comorbidities of the individual patient.

Nanoparticulate-based drug delivery systems for small molecule anti-diabetic drugs: An emerging paradigm for effective therapy

Emergence of nanoparticulate drug delivery systems in diabetes has facilitated improved delivery of small molecule drugs which could dramatically improve the quality of life for diabetics. Conventional dosage forms of the anti-diabetic drugs exhibit variable/less bioavailability and short half-life, demanding frequent dosing and causing increased side-effects resulting in ineffectiveness of therapy and non-compliance with the patients. Considering the chronic nature of diabetes, nanotechnology-based approaches are more promising in terms of providing site-specific delivery of drugs with higher bioavailability and reduced dosage regimen. Nanomedicines act at the cellular and molecular levels to enhance the uptake of the drug into the cells or block the efflux mechanisms thus retaining the drug inside the cell for a longer duration of time. Many studies have hinted at the possibility of administering peptide drugs like glucagon like peptides orally by encapsulation into nanoparticles. Nanoparticles also allow further modifications including their encapsulation into microparticles, polyethylene glycol (PEG)-PEGylation- or functionalization with ligands for active targeting. Nevertheless, such remarkable benefits are fraught with their long-term safety concerns, regulatory hurdles, limitations of scale-up and ineffective patent protection which have hindered their commercialization. This review summarizes the latest advances in the area of nanoformulations as applied to the delivery of anti-diabetics. STATEMENT OF SIGNIFICANCE: The present work describes the latest advancements in the area of nanoformulations for anti-diabetic therapy along with highlighting the advantages that these nanoformulations offer at molecular level for diabetes. Although several potent orally active anti-hyperglycemic agents are available, the current challenges in efficient management of diabetes include optimization of the present therapies to ensure an optimum and stable level of glucose, and also to reduce the occurrence of long term complications associated with diabetes. Nanoformulations because of their high surface area to volume ratio provide improved efficacy, targeting their delivery to the desired site of action tends to minimize adverse effects and administration of peptide drugs by oral route is also possible by encapsulating them in nanoparticles. As we reflect on the success and failures of latest research on nanoformulations for the treatment of diabetes, it is important not to dwell on lack of FDA approvals but rather define future directions that guarantee more effective anti-diabetic treatment. In proposed review we have explored the latest advancement in anti-diabetic nanotechnology based formulations.

The effect of individual and mixed rewards on diabetes management: A feasibility randomized controlled trial

Background: Incentives play a role in introducing health-related benefits, but no interventions using mixed incentives, i.e. a combination of individual and group incentives, have been tested in individuals with type 2 diabetes mellitus (T2DM). We evaluated the feasibility of implementing individual- and mixed-incentives, with and without a supportive partner, on glycated haemoglobin (HbA1c) control and weight loss among patients with T2DM. Methods: This is a feasibility, sex-stratified, single-blinded, randomized controlled study in individuals with T2DM. All participants received diabetes education and tailored goal setting for weight and glycated haemoglobin (HbA1c). Participants were randomly assigned into three arms: individual incentives (Arm 1), mixed incentives-altruism (Arm 2), and mixed incentives-cooperation (Arm 3). Participants were accompanied by a diabetes educator every other week to monitor targets, and the intervention period lasted 3 months. The primary outcome was the change in HbA1c at 3 months from baseline. Weight and change body mass index (BMI) were considered as secondary outcomes. Results: Out of 783 patients screened, a total of 54 participants, 18 per study arm, were enrolled and 44 (82%) completed the 3-month follow-up. Mean baseline HbA1c values were 8.5%, 7.9% and 8.2% in Arm 1, Arm 2, and Arm 3, respectively. At 3 months, participants in all three study arms showed reductions in HbA1c ranging from -0.9% in Arm 2 to -1.4% in Arm 1. Weight and BMI also showed reductions. Conclusions: Individual and mixed cash incentives show important reductions in HbA1c, weight and BMI in patients with type 2 diabetes mellitus after 3 months.  Recruitment and uptake of the intervention were successfully accomplished demonstrating feasibility to conduct larger effectiveness studies to test individual and mixed economic incentives for diabetes management. Registration: ClinicalTrials.gov Identifier NCT02891382.

Narrative review of the effects of antidiabetic drugs on albuminuria

Diabetes mellitus is the most prevalent metabolic disorder worldwide. Glycemic control is the main focus of antidiabetic therapy. However, there are data suggesting that some antidiabetic drugs may have intrinsic beneficial renal effects and protect against the development and progression of albuminuria, thus minimizing the risk of diabetic nephropathy. These pharmacological agents can suppress upstream molecular pathways involved in the pathophysiology of diabetes-induced renal dysfunction such as oxidative stress, inflammatory responses, and apoptosis. In this narrative review, the pathophysiology of albuminuria in patients with diabetic nephropathy is discussed. Furthermore, the renoprotective effects of antidiabetic drugs, focusing on albuminuria, are reviewed.

Chitosan encapsulated nanocurcumin induces GLUT-4 translocation and exhibits enhanced anti-hyperglycemic function

AIM

The present study was undertaken to develop a Curcumin nanoparticle system with chitosan as a hydrophilic carrier. In addition, the anti-diabetic potential of curcumin loaded chitosan nanoparticles were assessed in comparison to those of free curcumin by examining the anti-hyperglycemic efficacy using in vitro assays.

METHODS

Curcumin loaded chitosan nanoparticles were prepared and characterized for particle size by transmission electron microscopy, FT-IR, differential scanning calorimetry and therapeutic effects of curcumin loaded chitosan nanoparticles were evaluated by measuring the level of GLUT-4 present at the plasma membrane in L6myc myotubes followed by western blotting. Additionally, anti-inflammatory potential of curcumin loaded chitosan nanoparticles were assessed by enzyme immunoassay using appropriate ELISA kits.

KEY FINDINGS

Transmission electron microscopy revealed an average nanocurcumin particle size of 74 nm. Under in vitro conditions, treatment with chitosan-nanocurcumin (CS-NC) caused a substantial increase in the GLUT-4 translocation to the cell surface in L6 skeletal muscle cells and the effect was associated with increased phosphorylation of AKT (Ser-473) and its downstream target GSK-3β (Ser-9).

SIGNIFICANCE

The therapeutic potential of nanocurcumin is prominent than that of curcumin alone. Nanocurcumin could improve the solubility of curcumin and may prolong its retention in the systemic circulation.

Effect of Health Information Technologies on Glycemic Control Among Patients with Type 2 Diabetes

PURPOSE OF REVIEW

This study was to present meta-analysis findings across selected clinical trials for the effect of health information technologies (HITs) on glycemic control among patients with type 2 diabetes.

RECENT FINDINGS

HITs may be promising in diabetes management. However, findings on effect size of glycated hemoglobin level (HbA1c) yielded from HITs varied across previous studies. This is likely due to heterogeneity in sample size, adherence to standard quantitative method, and/or searching criteria (e.g., type of HITs, type of diabetes, specification of patient population, randomized vs. nonrandomized trials). We systematically searched Medline, Cumulative Index of Nursing and Allied Health Literature (CINAHL), and the Cochrane Library for peer-reviewed randomized control trials that studied the effect of HITs on HbA1c reduction. We also used Google Scholar and a hand search to identify additional studies. Thirty-four studies (40 estimates) met the criteria and were included in the analysis. Overall, introduction of HITs to standard diabetes treatment resulted in a statistically and clinically reduced HbA1c. The bias adjusted HbA1c reduction due to the combined HIT interventions was - 0.56 [Hedges' g = - 0.56 (- 0.70, - 0.43)]. The reduction was significant across each of the four types of HIT intervention under review, with mobile phone-based approaches generating the largest effects [Hedges' g was - 0.67 (- 0.90, - 0.45)]. HITs can be an effective tool for glycemic control among patients with type 2 diabetes. Future studies should examine long-term effects of HITs and explore factors that influence their effectiveness.

Self-Care and Self-Management Among Adolescent T2DM Patients: A Review

Uncontrolled hyperglycaemia can lead to macro- and microvascular complications. Adolescents with T2DM develop similar complications as in adults, including cardiovascular disease, stroke, myocardial infarction, renal insufficiency, and chronic renal failure. Although regular medical follow-up is essential to avoid long-term complications, patients with diabetes mellitus need to perform holistic self-care activities such as opting for a healthy diet, physical activity, self-monitoring, and proper medication. To the best of our knowledge, only a limited number of studies have focused on self-care activities and self-management, including self-care practices, supportive networks, and self-care education programs in adolescent with T2DM. Some of the studies focused on the appreciation of self-care in adolescents with T2DM. This review aimed to analyse self-care and self-management among adolescents with T2DM, and discuss the impact of self-care and self-management on glycaemic control. The difficulties faced by adolescents in self-managing their disease are also highlighted. Such information is essential for healthcare providers in promoting self-care practices among adolescents with T2DM. A thorough search of the literature was performed using three databases: Medline, Google Scholar, and Scopus. The articles focused on self-care and self-management of adolescents patients with T2DM aged between 12 and 19 years old were included. Findings from this review reveal that healthy food adaptation, adequate physical activity, proper medication practices, and regular glucose monitoring are the most common self-care practices. Parental involvement and clinician encouragement also contribute toward the practice of self-care and self-management among the adolescents with T2DM. In conclusion, independent self-management regimens and supportive networks for appropriate administration are vital factors to enhance clinical outcomes of adolescents with T2DM.

Metabolic impairments and tissue disorders in alloxan-induced diabetic rats are alleviated by Salvia officinalis L. essential oil

The current research explored for the first time the effect of Salvia officinalis L. (Sage) essential oil (EO) on Alloxan-induced diabetes in male Wistar rats. Sage EO was extracted by a Clevenger apparatus and analyzed by GC-FID and GC-MS. The most important chemical families identified in this oil were oxygenated monoterpenes (56.32%), hydrocarbon monoterpenes (15.00%) and hydrocarbon sesquiterpenes (14.70%). All treatments were administered orally. In vitro investigation showed that the EO had α-amylase and lipase inhibitory activities with IC₅₀ = 38 μg/mL and IC₅₀ = 52 μg/mL, respectively. In vivo experiments highlighted that the activities of serum α-amylase and lipase were reduced by 46.6% and 32.1%, respectively. Sage EO reduced glycemia by 60% and the level of glycogen stored in the liver by 43.7%. Treatments of diabetes with Sage EO significantly protected the liver function by lowering serum AST (35%), ALT (79%) and LDH (43%) activities. Furthermore, Sage EO was efficient to preserve the kidney function in diabetes by reverting back serum creatinine (47%) and UA (62.5%) concentrations to control values. The obtained results altogether evidenced that Sage EO had hypoglycemic and anti-obesity effects and could be a valuable complement in future diabetes therapy.

Metabolic syndrome: an update on diagnostic criteria, pathogenesis, and genetic links

Metabolic syndrome (MetS), today a major global public health problem, is a cluster of clinical, metabolic, and biochemical abnormalities, such as central adiposity, hypertension, insulin resistance, and dyslipidemias. These MetS-related traits significantly increase the risk of type 2 diabetes mellitus, adverse cardiac events, stroke, and hepatic steatosis. The pathogenesis of MetS is multifactorial, with the interplay of environmental, nutritional, and genetic factors. Chronic low-grade inflammation together with visceral adipose tissue, adipocyte dysfunction, and insulin resistance plays a major role in the progression of the syndrome by impairing lipid and glucose homeostasis in insulin-sensitive tissues, such as the liver, muscle, and adipocytes. Adipose-derived inflammatory cytokines and non-esterified fatty acids establish the link between central obesity IR, inflammation, and atherogenesis. Various studies have reported an association between MetS and related traits with single-nucleotide polymorphisms of different susceptibility genes. Modulation of cytokine levels, pro-oxidants, and disturbed energy homeostasis, in relation to the genetic variations, is described in this review of the recent literature, which also provides updated data regarding the epidemiology, diagnostic criteria, and pathogenesis of MetS.

Sericin enhances the insulin-PI3K/AKT signaling pathway in the liver of a type 2 diabetes rat model

The aim of the current study was to investigate the regulatory effect of sericin on the hepatic insulin-phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in a type 2 diabetes rat model. Male Sprague Dawley rats were randomly divided into four groups: Control group, diabetic model group, high-dose sericin group and low-dose sericin group, with 12 rats in each group. Fasting blood glucose was detected by the glucose oxidase method, and hepatic glycogen was determined by periodic acid-Schiff staining. The morphology of the liver was observed by hematoxylin and eosin staining. Immunohistochemical staining, western blotting and reverse transcription-quantitative polymerase chain reaction were used to determine the protein and mRNA expression levels of insulin receptor (IR), IR substrate-1 (IRS-1), PI3K and AKT. Compared with the control group, the blood glucose of the diabetic model group was significantly increased (P<0.05). The glycogen content and the expression levels of IR, IRS-1, PI3K and AKT in the diabetic model group were significantly lower (P<0.05), and the liver morphological structure of the diabetic model group exhibited obvious pathological changes compared with the control group. Compared with the diabetic model group, the blood glucose of the high- and low-dose sericin groups was significantly reduced, while the glycogen content and the expression levels of IR, IRS-1, PI3K and AKT in the sericin treatment groups were significantly increased (P<0.05). Additionally, the liver pathological changes of high-dose and low-dose sericin groups were markedly reduced. Sericin may enhance the signaling transduction effect of insulin by upregulating the expression levels of key factors (IR, IRS-1, PI3K and AKT) in the liver insulin-PI3K/AKT signaling pathway, thus promoting glucose transport and liver glycogen synthesis, and further reducing blood glucose.

A comprehensive review on xanthone derivatives as α-glucosidase inhibitors

α-Glucosidase plays an important role in carbohydrate metabolism and is therefore an attractive therapeutic target for the treatment of diabetes, obesity and other related complications. In the last two decades, considerable interest has been given to natural and synthetic xanthone derivatives in this field of research. Herein, a comprehensive review of the literature on xanthones as inhibitors of α-glucosidase activity, their mechanism of action, experimental procedures and structure-activity relationships have been reviewed for more than 280 analogs. With this overview we intend to motivate and challenge researchers (e.g. chemistry, biology, pharmaceutical and medicinal areas) for the design of novel xanthones as multipotent drugs and exploit the properties of this class of compounds in the management of diabetic complications.

The Effect of Morinda citrifolia L. Fruit Juice on the Blood Sugar Level and Other Serum Parameters in Patients with Diabetes Type 2

Background

The effect of the daily consumption of Morinda citrifolia (Noni) fruit juice on the physiological status of patients with diabetes type 2 (DT2) was tested over a period of two months.

Methods

Morinda citrifolia (Noni) fruit juice (NFJ), 2 ml per kg bw per day, was consumed by twenty patients with DT2 after they underwent a standard treatment regimen including carbohydrate reduced diet and treatment with an antidiabetic drug and/or insulin. NFJ consumption started only after no further improvement was achieved. The intake of NFJ was terminated after eight weeks. The fasting blood sugar level was monitored every morning during the entire treatment period. Blood samples were taken before, at, and four and eight weeks after the start of NFJ intake. The analysis of the blood samples included the concentration of blood glucose, HbA1c, C-peptide, hs-CRP, triglycerides, total cholesterol, LDL, and HDL.

Results

The consumption of NFJ by 20 patients with DT2 resulted in a significant mean decrease of the morning blood sugar level monitored over a period of eight weeks. While NFJ reduced the blood glucose level in several but not all hyperglycemic patients, it did not cause hypoglycemia in normoglycemic patients. NFJ consumption also reduced the mean HbA1c value significantly (p= 0.033). Significant decreases (p= 0.01) were also achieved for high sensitive CRP values in patients starting with high levels (>2 mg/L), whereas no change was observed in patients with normal values (< 2 mg/L). The level of C-peptide showed a significant mean increase after four weeks of NFJ consumption in those patients who started with low levels (<3 μg/l, p=0.004, N=11) but not in patients with higher levels (> 3 μg/L).

Conclusion

The daily consumption of NFJ has the potential to regulate elevated blood sugar levels and some other pathological parameters in patients with DT2. NFJ therefore serves as a suitable additive to the diet of diabetic patients.

National Rates of Initiation and Intensification of Antidiabetic Therapy Among Patients With Commercial Insurance

OBJECTIVE

Prompt initiation and intensification of antidiabetic therapy can delay or prevent complications from diabetes. We sought to understand the rates of and factors associated with the initiation and intensification of antidiabetic therapy among commercially insured patients in the U.S.

RESEARCH DESIGN AND METHODS

Using 2008-2015 commercial claims linked with laboratory and pharmacy data, we created an initiation cohort with no prior antidiabetic drug use and an HbA_1c ≥8% (64 mmol/mol) and an intensification cohort of patients with an HbA_1c ≥8% (64 mmol/mol) who were on a stable dose of one noninsulin diabetes drug. Using multivariable logistic regression, we determined the rates of and factors associated with initiation and intensification. In addition, we determined the percent of variation in treatment patterns explained by measurable patient factors.

RESULTS

In the initiation cohort (n = 9,799), 63% of patients received an antidiabetic drug within 6 months of the elevated HbA_1c test. In the intensification cohort (n = 10,941), 82% had their existing antidiabetic therapy intensified within 6 months of the elevated HbA_1c test. Higher HbA_1c levels, lower generic drug copayments, and more frequent office visits were associated with higher rates of both initiation and intensification. Better patient adherence prior to the elevated HbA_1c level, existing therapy with a second-generation antidiabetic drug, and lower doses of existing therapy were also associated with intensification. Patient factors explained 7.96% of the variation in initiation and 7.35% of the variation in intensification.

CONCLUSIONS

Approximately two-thirds of patients were newly initiated on antidiabetic therapy, and four-fifths of those already receiving antidiabetic therapy had it intensified within 6 months of an elevated HbA_1c in a commercially insured population. Patient factors explain 7-8% of the variation in diabetes treatment patterns.

Regeneration of insulin-producing islets from dental pulp stem cells using a 3D culture system

AIM

In this study, we aimed to establish the differentiation protocol of dental pulp stem cells (DPSCs) into pancreatic islets using a 3D structure.

MATERIALS & METHODS

DPSCs were differentiated in a 3D culture system using a stepwise protocol. Expression of β-cell markers, glucose-stimulated insulin secretion, and PI3K/AKT and WNT pathways were compared between monolayer-cultured pancreatic cells and islets.

RESULTS

Islet formation increased insulin and C-peptide production, and enhanced the expression of pancreatic markers. Glucose-dependent secretion of insulin was increased by islets. Pancreatic endocrine markers, transcriptional factors, and the PI3K/AKT and WNT pathways were also upregulated.

CONCLUSION

Pancreatic islets were generated from DPSCs in a 3D culture system. This system could provide novel strategies for controlling diabetes through regenerative medicine.

Effect of Catha edulis (khat) on pancreatic functions in streptozotocin-induced diabetes in male Sprague-Dawley rats

People consume Catha edulis (khat) for its euphoric effect, and type 1 diabetics have claimed that khat could reduce elevated levels of blood sugar. However, khat has been suggested to provoke diabetes mellitus through destruction of pancreatic β-cells. This study investigated the effect of an ethanolic khat extract on pancreatic functions in type 1 diabetes (T1DM)-induced male Sprague-Dawley rats and to assess its in vitro cytotoxicity in rat pancreatic β-cells (RIN-14B). T1DM was induced in a total of 20 rats with a single intraperitoneal injection of 75 mg/kg of streptozotocin. The rats were distributed into four groups (n=5): the diabetic control, 8 IU insulin-treated, 200 mg/kg khat-treated, and 400 mg/kg khat-treated groups. Another 5 rats were included as a nondiabetic control. Body weight, fasting blood sugar, and caloric intake were recorded weekly. Four weeks after treatment, the rats were sacrificed, and blood was collected for insulin, lipid profile, total protein, amylase, and lipase analysis, while pancreases were harvested for histopathology. In vitro, khat exerted moderate cytotoxicity against RIN-14B cells after 24 and 48 h but demonstrated greater inhibition against RIN-14B cells after 72 h. Neither 200 mg/kg nor 400 mg/kg of khat produced any significant reduction in blood sugar; however, 200 mg/kg khat extract provoked more destruction of pancreatic β-cells as compared with the diabetic control. Ultimately, neither 200 mg/kg nor 400 mg/kg of khat extract could produce a hypoglycemic effect in T1DM-induced rats. However, 200 mg/kg of khat caused greater destruction of pancreatic β-cells, implying that khat may cause a direct cytotoxic effect on pancreatic β-cells in vitro.

Glucagon-Like peptide-1: A new therapeutic target to treat abdominal aortic aneurysm?

Recent antidiabetic drugs including GLP-1 receptor agonists and DPP-IV inhibitors have demonstrated protective effects in several cardiovascular diseases but their effect in abdominal aortic aneurysm (AAA) is far less known. AAA can be associated with extremely high rates of mortality and pharmacological treatments are still lacking underlining the real need to identify new therapeutic targets. The aim of this review was to summarize current knowledge on the role of GLP-1 pathway in AAA. A systematic literature review was performed and 6 relevant studies (2 clinical and 4 experimental) were included. Experimental studies demonstrated a protective effect of both GLP-1 receptor agonists and DPP-IV inhibitors through targeting the main pathophysiological mechanisms underlying AAA formation. The effects of these drugs in human AAA are still poorly known. In the limelight of clinical and experimental studies, we discuss current limits and future directions.

Ethanolic Extract of Caesalpinia bonducella f. Seed Ameliorates Diabetes Phenotype of Streptozotocin- Nicotinamide-Induced Type 2 Diabetes Rat

Caesalpinia bonducella F. (Leguminosae) is widely used medicinal plant which contains flavonoid, tannin, saponin, and a potent antioxidant activity. However, the antihyperglycemic effect of the seed of C. bonducella is remained to be evaluated. This study used 24 male Wistar albino rats that were induced for type 2 diabetes with streptozotocin (STZ) and nicotinamide (NA). The rats were divided into three groups: the distilled water-treated group (NC group), glibenclamide-treated group (10 mg/kg/d, oral; PC group), and C. bonducella seed extract-treated group (500 mg/kg/d, oral; T group). Blood glucose and plasma insulin measurements were done after 14 days of treatment. The results showed that the postprandial blood glucose (PPBG) level of both PC and T groups were decreased significantly (p < 0.01 for both), whereas in NC group, the PPBG level was rising (p < 0.01). Glibenclamide was found to be more effective to decrease the PPBG level than C. bonducella seed extract (p < 0.01). The post-test fasting insulin level of T group was higher than other groups (p < 0.05). In summary, our results suggest that ethanolic extract of C. bonducella seed possesses antidiabetic activity against experimentally-induced type 2 diabetes.

Diabetes mellitus: A review of some of the prognostic markers of response to treatment and management

Background: The WHO defined ‘diabetes mellitus’ (DM) as a metabolic disorder characterised by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from the defect in insulin secretion, or inaction, or both. When not identified early and controlled, acute and chronic life-threatening consequences may result. Identifying DM early for treatment and management, as well as clinically monitoring recovery and improvement during treatment, involves the assessments of biomarkers. The types, choice, sensitivity and descriptive information trends of these biomarkers are very important. Aim: Some prognostic biomarkers and parameters that this review identified include glycated haemoglobin, white blood cells, mean neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, total leukocytes and neutrophils, plasma low-density lipoprotein, high-density lipoprotein and very low-density lipoprotein, platelet, fibrinogen, D-dimer and C-reactive proteins. Results: These parameters display increases in DM, while red blood cell, haemoglobin concentration, activated partial thromboplastin time, prothrombin time and partial thromboplastin time are decreased. Conclusion: With sound knowledge of the variations of these markers and parameters, observed reversal during treatment and management of DM and its complications can be better monitored, and guided decisions can be made.

Antidiabetic effect of Euterpe oleracea Mart. (açaí) extract and exercise training on high-fat diet and streptozotocin-induced diabetic rats: A positive interaction

A growing body of evidence suggests a protective role of polyphenols and exercise training on the disorders of type 2 diabetes mellitus (T2DM). We aimed to assess the effect of the açaí seed extract (ASE) associated with exercise training on diabetic complications induced by high-fat (HF) diet plus streptozotocin (STZ) in rats. Type 2 diabetes was induced by feeding rats with HF diet (55% fat) for 5 weeks and a single dose of STZ (35 mg/kg i.p.). Control (C) and Diabetic (D) animals were subdivided into four groups each: Sedentary, Training, ASE Sedentary, and ASE Training. ASE (200 mg/kg/day) was administered by gavage and the exercise training was performed on a treadmill (30min/day; 5 days/week) for 4 weeks after the diabetes induction. In type 2 diabetic rats, the treatment with ASE reduced blood glucose, insulin resistance, leptin and IL-6 levels, lipid profile, and vascular dysfunction. ASE increased the expression of insulin signaling proteins in skeletal muscle and adipose tissue and plasma GLP-1 levels. ASE associated with exercise training potentiated the reduction of glycemia by decreasing TNF-α levels, increasing pAKT and adiponectin expressions in adipose tissue, and IR and pAMPK expressions in skeletal muscle of type 2 diabetic rats. In conclusion, ASE treatment has an antidiabetic effect in type 2 diabetic rats by activating the insulin-signaling pathway in muscle and adipose tissue, increasing GLP-1 levels, and an anti-inflammatory action. Exercise training potentiates the glucose-lowering effect of ASE by activating adiponectin-AMPK pathway and increasing IR expression.

Huntington's Disease and Diabetes: Chronological Sequence of its Association

Although Huntington’s disease (HD) is primarily considered a rare neurodegenerative disorder, it has been linked to glucose metabolism alterations and diabetes, as has been described in other neuro syndromes such as Friedreich’s ataxia or Alzheimer’s disease. This review surveys the existing literature on HD and its potential relationship with diabetes, glucose metabolism-related indexes and pancreas morphology, in humans and in animal’s models. The information is reported in chronological sequence. That is, studies performed before and after the identification of the genetic defect underlying HD (CAG: encoding glutamine ≥36 repeats located in exon 1 of the HTT gene) and with the development and evolution of HD animal models. The aim of the review is to evaluate whether impaired glucose metabolism contributes to the development of HD, and whether optimized glycemic control may ameliorate the symptoms of HD.

Lower glycemic indices and lipid profile among type 2 diabetes mellitus patients who received novel dose of Silybum marianum (L.) Gaertn. (silymarin) extract supplement: A Triple-blinded randomized controlled clinical trial

OBJECTIVE

This randomized clinical trial was conducted to evaluate the effects of silymarin supplementation on glycemic indices and serum lipid profile in type 2 diabetes mellitus (T2DM) patients.

METHODS

40 T2DM patients (twenty male and twenty female), 25-50 years of age and on stable medication, were recruited for the present paralleled, randomized, triple-blinded, placebo-controlled clinical trial. The participants were randomly assigned to the silymarin or placebo groups, in which the patients either received 140 mg of silymarin, thrice daily (n = 20) or placebo (n = 20) for 45 days. Anthropometric and dietary intake data were collected at the baseline and end of the trial. Fasting blood samples were collected, and glycemic indices and lipid profile were determined at baseline, as well as the end of the study.

RESULTS

Silymarin supplementation led to significant reduction in fasting blood sugar, serum insulin, homeostatic model assessment for insulin resistance, serum triglyceride and triglyceride to high-density lipoprotein cholesterol ratio as compared to the placebo, by 11.01, 14.35, 25.92, 23.7 and 27.67% respectively. There was significant increase in high-density lipoprotein cholesterol levels and quantitative insulin sensitivity check index in the silymarin group as compared to the placebo group, by 6.88 and 5.64% respectively, (p < 0.05). Total cholesterol and low-density lipoprotein cholesterol concentrations significantly decreased in the silymarin group as compared to the baseline, by 7.93 (p = 0.001) and 7.15% (p = 0.02), respectively.

CONCLUSION

Silymarin supplementation may improve the glycemic indices and lipid profiles of T2DM patients. More studies are needed to validate the adjunct use of silymarin for metabolic control of T2DM patients.

Pharmacogenetics of oral antidiabetic therapy

Type 2 diabetes prevalence is still on the rise worldwide. Antidiabetic drugs are widely prescribed to patients with Type 2 diabetes. Most patients start with metformin which is mostly well tolerated. However, a high percentage of patients fail to achieve glycemic control. The effectiveness of metformin as well as most other antidiabetic drugs depends among other factors on interindividual genetic differences that are up to now ignored in the treatment of Type 2 diabetes. Interestingly, many genes influencing the effectiveness of antidiabetic drugs are Type 2 diabetes risk genes making matters worse. Here, we shed light on these interindividual genetic differences.

The effectiveness, reproducibility, and durability of tailored mobile coaching on diabetes management in policyholders: A randomized, controlled, open-label study

This randomized, controlled, open-label study conducted in Kangbuk Samsung Hospital evaluated the effectiveness, reproducibility, and durability of tailored mobile coaching (TMC) on diabetes management. The participants included 148 Korean adult policyholders with type 2 diabetes divided into the Intervention-Maintenance (I-M) group (n = 74) and Control-Intervention (C-I) group (n = 74). Intervention was the addition of TMC to typical diabetes care. In the 6-month phase 1, the I-M group received TMC, and the C-I group received their usual diabetes care. During the second 6-month phase 2, the C-I group received TMC, and the I-M group received only regular information messages. After the 6-month phase 1, a significant decrease (0.6%) in HbA1c levels compared with baseline values was observed in only the I-M group (from 8.1 ± 1.4% to 7.5 ± 1.1%, P < 0.001 based on a paired t-test). At the end of phase 2, HbA1c levels in the C-I group decreased by 0.6% compared with the value at 6 months (from 7.9 ± 1.5 to 7.3 ± 1.0, P < 0.001 based on a paired t-test). In the I-M group, no changes were observed. Both groups showed significant improvements in frequency of blood-glucose testing and exercise. In conclusion, addition of TMC to conventional treatment for diabetes improved glycemic control, and this effect was maintained without individualized message feedback.

Structural Dynamics of DPP-4 and Its Influence on the Projection of Bioactive Ligands

Dipeptidyl peptidase-4 (DPP-4) is a target to treat type II diabetes mellitus. Therefore, it is important to understand the structural aspects of this enzyme and its interaction with drug candidates. This study involved molecular dynamics simulations, normal mode analysis, binding site detection and analysis of molecular interactions to understand the protein dynamics. We identified some DPP-4 functional motions contributing to the exposure of the binding sites and twist movements revealing how the two enzyme chains are interconnected in their bioactive form, which are defined as chains A (residues 40-767) and B (residues 40-767). By understanding the enzyme structure, its motions and the regions of its binding sites, it will be possible to contribute to the design of new DPP-4 inhibitors as drug candidates to treat diabetes.

Antidiabetic effect of Achillea millefollium through multitarget interactions: α-glucosidases inhibition, insulin sensitization and insulin secretagogue activities

ETHNOPHARMACOLOGICAL IMPORTANCE

Achillea millefolium L. (Asteraceae) is a perennial herb used in Mexican folk medicine for treatment of several pathologies, including inflammatory and spasmodic gastrointestinal disorders, hepatobiliary complaints, overactive cardiovascular, respiratory ailments and diabetes.

AIM OF THE STUDY

To evaluate the potential antidiabetic effect in vivo and to establish the potential mode of action through in vitro approaches of Achillea millefolium.

MATERIALS AND METHODS

The antidiabetic effect of hydroalcoholic extract of Achillea millefolium (HAEAm) was evaluated on the oral glucose tolerance tests, in normoglycemic and experimental Type 2 diabetic mice models. In addition, we evaluated the possible mode of action in in vitro assays to determine α-glucosidases inhibition, the insulin secretion and calcium mobilization in RINm5F cells and PPARγ and GLUT4 expression in 3T3-L1 cells.

RESULTS

HAEAm showed significant glucose diminution on oral glucose tolerance test and in acute experimental Type 2 diabetic assay with respect to the control (p < 0.05). In addition, HAEAm promoted the α-glucosidases inhibition by 55% at 1mg/ml respect to control. On the other hand, HAEAm increased the PPARγ (five-times) and GLUT4 (two-fold) relative expression than control (p < 0.05). Finally, HAEAm significantly increased the insulin secretion and [Ca²⁺]_i compared with control.

CONCLUSION

The HAEAm possesses in vivo antidiabetic effect, having such effect through multitarget modes of action that involve antihyperglycemic (α-glucosidases inhibition), hypoglycemic (insulin secretion) and potential insulin sensitizer (PPARγ/GLUT4 overexpression) actions.

Antidiabetic drugs and stroke risk. Current evidence

Cardiovascular disease (CVD) is the major cause of morbidity and mortality for individuals with type 2 diabetes (T2D). In particular, the risk for stroke is twice that of patients without diabetes, and diabetes may be responsible for >8% of first ischemic strokes. Therefore, the way to prevent stroke in these patients has become an important issue. Traditionally, glucose-lowering drugs had not been shown to protect against stroke. Moreover, several antidiabetic drugs (i.e., sulfonylureas, rosiglitazone) have been reported to be associated with increased risks of CVD and stroke. On the contrary, data on the CV risks and benefits associated with new antidiabetic treatment in patients with T2D are emerging - and look promising. Therefore, it could be of great value to find out if any type of these new antidiabetic agents has protective effect against stroke. We review the available evidence regarding the risk of stroke in individuals taking non-insulin antidiabetic agents. To date, several antidiabetic agents have shown to have a positive effect on stroke prevention. The accumulated evidence suggests that metformin, pioglitazone and semaglutide reduce stroke risk. These agents do not represent only a way of controlling blood glucose and but also offer the opportunity to reduce stroke risk. Surely, new data from ongoing and future studies will provide additional information to select the best treatment for decreasing stroke risk in T2D patients.

Peptides from frog skin with potential for development into agents for Type 2 diabetes therapy

Several frog skin peptides, first identified as result of their antimicrobial or immunomodulatory activities, have subsequently been shown to stimulate insulin release both in vitro and in vivo and so show potential for development into incretin-based drugs for treatment of patients with Type 2 diabetes mellitus. However, their therapeutic potential as anti-diabetic agents is not confined to this activity as certain frog skin-derived peptides, such as magainin-AM2 and CPF-SE1 and analogs of hymenochirin-1B, tigerinin-1R, and esculentin-2CHa, have been shown to increase insulin sensitivity, promote β-cell proliferation, suppress pancreatic and circulating glucagon concentrations, improve the lipid profile, and selectively alter expression of genes involved in insulin secretion and action in mice with diet-induced obesity, insulin resistance and impaired glucose tolerance. This review assesses the therapeutic possibilities of peptides from frogs belonging to the Pipidae, Dicroglossidae, and Ranidae families, focusing upon work that has been carried out since 2014.

Antidiabetic Potential of Monoterpenes: A Case of Small Molecules Punching above Their Weight

Monoterpenes belong to the terpenoids class of natural products and are bio-synthesized through the mevalonic acid pathway. Their small molecular weight coupled with high non-polar nature make them the most abundant components of essential oils which are often considered to have some general antioxidant and antimicrobial effects at fairly high concentrations. These compounds are however reported to have antidiabetic effects in recent years. Thanks to the ingenious biosynthetic machinery of nature, they also display a fair degree of structural complexity/diversity for further consideration in structure-activity studies. In the present communication, the merit of monoterpenes as antidiabetic agents is scrutinized by assessing recent in vitro and in vivo studies reported in the scientific literature. Both the aglycones and glycosides of these compounds of rather small structural size appear to display antidiabetic along with antiobesity and lipid lowering effects. The diversity of these effects vis-à-vis their structures and mechanisms of actions are discussed. Some key pharmacological targets include the insulin signaling pathways and/or the associated PI3K-AKT (protein kinase B), peroxisome proliferator activated receptor-γ (PPARγ), glucose transporter-4 (GLUT4) and adenosine monophosphate-activated protein kinase (AMPK) pathways; proinflammatory cytokines and the NF-κB pathway; glycogenolysis and gluconeogenesis in the liver; glucagon-like-1 receptor (GLP-1R); among others.

Restoration of Impaired Metabolic Energy Balance (ATP Pool) and Tube Formation Potential of Endothelial Cells under "high glucose", Diabetic Conditions by the Bioinorganic Polymer Polyphosphate

Micro-vascularization is a fast, energy-dependent process that is compromised by elevated glucose concentrations such as in diabetes mellitus disease. Here, we studied the effect of the physiological bioinorganic polymer, polyphosphate (polyP), on the reduced ATP content and impaired function of endothelial cells cultivated under "high glucose" (35 mM diabetes mellitus conditions) concentrations. This high-energy biopolymer has been shown to provide a source of metabolic energy, stored in its phosphoanhydride bonds. We show that exposure of human umbilical vein endothelial cells (HUVEC cells) to "high glucose" levels results in reduced cell viability, increased apoptotic cell death, and a decline in intracellular ATP level. As a consequence, the ability of HUVEC cells to form tube-like structures in the in vitro cell tube formation assay was almost completely abolished under "high glucose" conditions. Those cells were grown onto a physiological collagen scaffold (collagen/basement membrane extract). We demonstrate that these adverse effects of increased glucose levels can be reversed by administration of polyP to almost normal values. Using Na-polyP, complexed in a stoichiometric (molar) ratio to Ca2+ ions and in the physiological concentration range between 30 and 300 µM, an almost complete restoration of the reduced ATP pool of cells exposed to "high glucose" was found, as well as a normalization of the number of apoptotic cells and energy-dependent tube formation. It is concluded that the adverse effects on endothelial cells caused by the metabolic energy imbalance at elevated glucose concentrations can be counterbalanced by polyP, potentially opening new strategies for treatment of the micro-vascular complications in diabetic patients.

Investigation into Hypoglycemic, Antihyperlipidemic, and Renoprotective Potentials of Dennettia tripetala (Pepper Fruit) Seed in a Rat Model of Diabetes

This study investigated the hypoglycemic, antihyperlipidemic, and renoprotective potentials of Dennettia tripetala (DT) in a rat model of diabetes. The hypoglycemic activity in crude methanol seed extract of DT (CMEDT) and methanol seed fraction of DT (MFDT) measured by glucose oxidase method was increased by 47.37% and 28.72%, respectively, after 8 hours of administration. After 10 days of treatment, CMEDT and MFDT gave a good glycemic control with the highest percentage reduction of 75.82% and 71.34% in glucose level, respectively, which is closely compared with 79.91% in glibenclamide. Using the enzymatic assay and Friedewald's equation, there was a significant reduction in serum level of total cholesterol (TC), triglyceride (TG), very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) and a significant increase in high-density lipoprotein (HDL) (p < 0.05) following treatment with CMEDT and MFDT, when compared with the untreated group, although results varied in dosed groups, with high dose of MFDT showing a better lipid-lowering activity. High dose of MFDT improved lipid metabolism and increased percentage protection against atherogenesis by 44%. However, neither CMEDT nor MFDT ameliorated the renal biochemical alteration in urea and creatinine. Thus, the study demonstrates hypoglycemic and antihyperlipidemic potentials of DT seed in diabetes.

Quercetin/oleic acid-based G-protein-coupled receptor 40 ligands as new insulin secretion modulators

Aim: Management of Type 2 diabetes mellitus by diet is achievable at the early stage of the disease; patients usually underestimate this approach and an appropriate drug therapy is required. Results: Starting from quercetin and oleic acid, that have effect on insulin secretion, a small set of hybrid molecules was synthesized. Insulin secretion was evaluated in both in vitro and ex vivo models.  AV1  was able to enhance insulin secretion dose dependently, behaving as a conceivable agonist of G-protein-coupled receptor 40. Conclusion: AV1 represents an interesting tool that interacts with G-protein-coupled receptor 40. Further studies will be carried out to evaluate the exact binding mode, and also to enlarge the library of these antidiabetic agents.

[Formula: see text]