Oral anti-diabetic drugs for the prevention of Type 2 diabetes

Investigation of anti-diabetic potential and molecular simulation studies of dihydropyrimidinone derivatives

In an attempt to find new targets for α-amylase and α-glucosidase for the treatment of type 2 diabetes mellitus, the present study aims in determining the anti-diabetic potential of synthesized dihydropyrimidinone derivatives. The in vitro α-glucosidase and α-amylase inhibitory activity was performed and the molecular docking analysis of the ligand in the active binding site of target protein was determined. The results revealed significant percent inhibition of α-glucosidase by the compound 6-benzyl-4-(4-hydroxyphenyl)-3,4,6,7-tetrahydro-1H-pyrrolo[3,4-d]pyrimidine-2,5-dione (compound A). The active compound showed 81.99% inhibition when compared to standard ascorbic acid having percent inhibition 81.18%. The IC₅₀ of active compound (A) showed to be 1.02 µg/ml. The molecular docking analysis revealed that the ligand bound to the active binding site of protein with the lowest binding energy of -7.9 kcal/mol that was also significantly similar to standard having -7.8 kcal/mol binding energy. The molecular dynamic simulation studies also revealed stable binding of ligand in the active binding site of protein with low RMSD of 1.7 Å similar to the protein RMSD 1.6Å In conclusion, the study revealed a potential new target against α-glucosidase to treat type 2 diabetes mellitus.

Improved Biomedical Properties of Polydopamine-Coated Carbon Nanotubes

Carbon nanotubes (CNTs) due to their outstanding mechanical, thermal, chemical, and optical properties were utilized as a base material and were coated with polydopamine (PDA) (PDA@CNT) via the simple self-polymerization of dopamine (DA). Then, PDA@CNT coatings of up to five layers were examined for potential biomedical applications. The success of multiple coating of CNTs with PDA was confirmed via increased weight loss values with the increased number of PDA coatings of CNTs at 500 °C by thermogravimetric analysis. The surface area of bare CNTs was measured as 263.9 m2/g and decreased to 197.0 m2/g after a 5th coating with PDA. Furthermore, the antioxidant activities of CNT and PDA@CNTs were determined via total flavonoid content (TFC), total phenol content (TPC), and Fe(III)-reducing antioxidant power (FRAP) tests, revealing the increased antioxidant ability of PDA@CNTs with the increasing numbers of PDA coatings. Moreover, a higher inhibition percentage of the activity of the alpha-glucosidase enzyme with 95.1 ± 2.9% inhibition at 6 mg/mL PDA-1st@CNTs concentration was found. The CNT and PDA@CNTs exhibited blood compatibility, less than a 2.5% hemolysis ratio, and more than 85% blood clotting indexes. The minimum inhibition concentration (MIC) of PDA-5th@CNTs against E. coli and S. aureus bacteria was determined as 10 mg/mL.

Improving Dissolution and Cytotoxicity by Forming Multidrug Crystals

Both rosiglitazone and metformin have effects on blood glucose regulation and the proliferation of liver cancer cells. Combination therapy with these two drugs is common and effective for the treatment of diabetes in the clinic, however, the application of these two drugs is influenced by the poor dissolution of rosiglitazone and the gastrointestinal side-effect of metformin resulting from a high solubility. The formation of a multidrug crystal form (Rsg-Met) by a solvent evaporation method can solve the solubility issue. Crystal structure data and intramolecular hydrogen bonds were detected by X-ray diffraction and infrared spectroscopy. Surprisingly, Rsg-Met shortens the time spent in solubility equilibrium and multiplies the dissolution rate of Rsg. Finally, we found that a low concentration of Rsg-Met enhanced the proliferation inhibition effect on liver cancer cells (HepG2, SK-hep1) compared with rosiglitazone, without affecting the human normal cell line LO2.

Medications affecting the biochemical conversion to type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

The extent to which some pharmacological interventions reduce or increase the risk of biochemical conversion to T2DM in at-risk individuals is unclear.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Scopus through August 24, 2017, for randomized controlled trials evaluating the effect of drugs suspected to modify the risk of biochemical conversion to T2DM.

RESULTS

We included 43 trials with 192,156 subjects (mean age 60 years; 56% men; mean BMI 30.4 kg/m2). Alpha-glucosidase inhibitors, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, metformin, orlistat, phentermine-topiramate and pioglitazone significantly reduced the risk of biochemical conversion to T2DM, whereas statins and nateglinide increased the risk. There was insufficient direct evidence regarding the effects of sulfonylureas, glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter-2 inhibitors. Most trials were brief and evaluated this outcome during treatment without a withdrawal or washout period.

CONCLUSIONS

Several drugs modify the risk of biochemical conversation to T2DM, although whether this effect is persistent and clinically relevant is unclear. Future studies need to focus on cardiovascular disease prevention, mortality and patient-important outcomes instead of biochemical conversion to T2DM.

Rosiglitazone metformin adduct inhibits hepatocellular carcinoma proliferation via activation of AMPK/p21 pathway

Background

Rosiglitazone metformin adduct (RZM) is a novel compound, synthesized from rosiglitazone (Ros) and metformin (Met) combined at a molar mass ratio of 1:1. Met and Ros are widely used together for treating type 2 diabetes to improve drug effectiveness and reduce adverse drug reactions. Recent studies reported that both Met and Ros may possess antineoplastic properties in several cancers, including hepatocellular carcinoma (HCC). However, the effects of RZM in HCC and its underlying mechanisms remain unknown.

Methods

RZM was synthesized from Ros and Met at an equal molar ratio and identified by infrared spectroscopy. MTS and colony formation assays were performed to detect proliferative repression of RZM, the mixture, Met and Ros, respectively. Tumorigenesis assay in vivo was used to confirm the anti-tumorigenesis potential of RZM and Met. Moreover, cellular apoptosis caused by RZM was analyzed by hoechst staining assay and flow cytometry. RT-qPCR and western blotting were performed to reveal mechanisms for the function of RZM.

Results

Both in vitro and in vivo data showed that low doses of RZM enhanced inhibitory effect on HCC cells growth compared with Met. Flow cytometry analysis confirmed that treatment with RZM at 1 mM for 48 h triggered HCC cells apoptosis. RT-qPCR and western blotting analyses showed that p21 was upregulated in response to 1 mM RZM treatment. Furthermore, RZM could increase AMPK activation compared with Met. The increased p21 expression induced by RZM treatment was attenuated by an AMPK inhibitor compound C.

Conclusions

All these observations demonstrate that RZM increases the antiproliferative effect of Met in HCC via upregulating p21 expression in an AMPK-dependent manner. Our results suggest that RZM has the potential to be an adjuvant for HCC therapy.

Prevention of type 2 diabetes: what is the right target population?

INTRODUCTION

Prevention of type 2 diabetes (T2D) is important to reduce suffering and health care costs. A precursor to T2D is impaired glucose regulation (IGR), a condition of elevated plasma glucose that is associated with insulin resistance and increased risk of cardiovascular disease. Prevention of T2D is determined by preservation of pancreatic β cell function which can be achieved by the use of anti-hyperglycemic medications or intensive lifestyle interventions (ILIs) to modify dietary and physical activity habits that induce modest weight loss (≥5%). Both interventions have beneficial effects on normal glucose regulation (NGR), but ILI is preferred due to its safety, efficacy, and cost.

AREAS COVERED

Traditional approaches to the prevention of T2D have used a variety of screening methods to identify those who are at high risk for developing T2D (prediabetes). People designated with prediabetes are then treated with ILI. An alternative approach for preventing T2D is to offer ILI to all overweight/obese adults who volunteer for weight loss treatment.

EXPERT COMMENTARY

This new alternative has several potential advantages: more rapid recruitment of participants with lower burden of care and early, aggressive treatment of potential β cell dysfunction. Cost-effectiveness studies of this alternative approach are needed.

Pharmaceutical Interventions for Diabetes Prevention in Patients at Risk

With the rising incidence and prevalence rates of type 2 diabetes globally, it is imperative that diabetes prevention strategies are implemented to stem the flow of new cases. Successful interventions include both lifestyle modification and pharmaceutical agents, and large, multicentre, randomised, controlled studies in different populations have identified the benefits of both. However, translating positive trial outcomes to the real world is particularly challenging, as lifestyle interventions require regular reinforcement from healthcare professionals to be maintained. Pharmaceutical therapies may therefore play an adjunctive role in combination with lifestyle to prevent diabetes. Population-based strategies are also necessary to reduce sedentary behaviour and obesity. Well-established glucose-lowering therapies such as metformin, sulphonylureas, thiazolidinediones and insulin and newer agents such as incretin therapies and sodium glucose co-transporter 2 inhibitors have all been investigated in randomised controlled trials for diabetes prevention with varying success. Non-glucose-lowering therapies such as orlistat and renin angiotensin system blockers can prevent diabetes, whereas statins are associated with slightly increased risk. Diabetes prevention strategies should carefully consider the use of these agents according to individual patient circumstances and phenotypic profile.

Incident Type 2 diabetes and the effect of early regression to normoglycaemia in a population with impaired glucose regulation

AIMS

To report contemporary regression rates from impaired glucose regulation to normal glucose tolerance, identify modifiable factors associated with early regression, and establish whether it affects subsequent diabetes risk in a population-based cohort.

METHODS

Participants with impaired glucose regulation (impaired fasting glucose and/or impaired glucose tolerance on a 75-g oral glucose tolerance test) at baseline in the UK-based ADDITION-Leicester study had annual Type 2 diabetes re-screens for 5 years or until diabetes diagnosis. Logistic regression models investigated modifiable risk factors for regression to normal glucose tolerance at 1 year (n = 817). Cox regression models estimated subsequent diabetes risk (n = 630).

RESULTS

At 1 year, 54% of participants had regressed to normal glucose tolerance, and 6% had progressed to diabetes. Regression to normal glucose tolerance was associated with weight loss of 0.1-3% [adjusted odds ratio 1.81 (95% CI 1.08, 3.03) compared with maintaining or gaining weight] and a waist circumference reduction of > 3 cm [adjusted odds ratio 1.78 (95% CI 1.03, 3.06) compared with maintaining or increasing waist circumference]. Those with normal glucose tolerance at 1 year subsequently had lower diabetes risk than those who remained with impaired glucose regulation [adjusted hazard ratio 0.19 (95% CI 0.10, 0.37)].

CONCLUSIONS

Early regression to normal glucose tolerance was associated with reduced diabetes incidence, and might be induced by small reductions in weight or waist circumference. If confirmed in experimental research, this could be a clear and achievable target for individuals diagnosed with impaired glucose regulation.

Evaluation of patients with type 2 diabetes mellitus receiving treatment during the pre-diabetes period: Is early treatment associated with improved outcomes?

AIM

This study evaluates the association of pretreatment with oral antidiabetics (OADs) on clinical outcomes and health resource utilization among commercially insured type II diabetes mellitus (T2DM) patients in the United States.

METHODS

Using administrative data (Truven MarketScan® Research Databases), patients diagnosed with T2DM between 2007 and 2014 with ⩾6months continuous enrolment pre- and post-diagnosis were evaluated. Pretreatment was defined as OAD use at least 3months prior to T2DM diagnosis. Time-to-insulin initiation and healthcare costs were compared by OAD pretreatment status.

RESULTS

Of the 866,605 patients studied, 241,856 (27.9%) were pretreated prior to T2DM diagnosis. Mean follow-up was 2.9years for pretreatment and 3.1years for those without pretreatment. Monthly diabetes-related pharmacy costs were significantly higher among pretreated patients ($66 versus $36, p<0.0001), as were overall monthly pharmacy costs ($255 versus $198, p<0.0001). Pretreated patients had lower mean monthly costs, both total ($625 versus $671, p<0.0001) and diabetes-related ($207 versus $214, p=0.0012). After multivariable adjustment, mean monthly diabetes-related total healthcare costs were higher among pretreated patients (+$60) but total all-cause monthly healthcare costs were significantly lower (-$354) (both p<0.05). Pretreatment was associated with a lower insulin initiation probability for 2years, after which probability was similar; the adjusted hazard ratio for pretreatment in a time-to-insulin model was 0.96 (95% CI, 0.94-0.97).

CONCLUSIONS

Pretreatment with OADs is associated with a modest delay in initiating insulin therapy and lower total healthcare costs. The clinical and pharmacoeconomic benefits of pretreatment should be elucidated in a prospective study.

Update and Next Steps for Real-World Translation of Interventions for Type 2 Diabetes Prevention: Reflections From a Diabetes Care Editors' Expert Forum

The International Diabetes Federation estimates that 415 million adults worldwide now have diabetes and 318 million have impaired glucose tolerance. These numbers are expected to increase to 642 million and 482 million, respectively, by 2040. This burgeoning pandemic places an enormous burden on countries worldwide, particularly resource-poor regions. Numerous landmark trials evaluating both intensive lifestyle modification and pharmacological interventions have persuasively demonstrated that type 2 diabetes can be prevented or its onset can be delayed in high-risk individuals with impaired glucose tolerance. However, key challenges remain, including how to scale up such approaches for widespread translation and implementation, how to select appropriately from various interventions and tailor them for different populations and settings, and how to ensure that preventive interventions yield clinically meaningful, cost-effective outcomes. In June 2015, a Diabetes Care Editors' Expert Forum convened to discuss these issues. This article, an outgrowth of the forum, begins with a summary of seminal prevention trials, followed by a discussion of considerations for selecting appropriate populations for intervention and the clinical implications of the various diagnostic criteria for prediabetes. The authors outline knowledge gaps in need of elucidation and explore a possible new avenue for securing regulatory approval of a prevention-related indication for metformin, as well as specific considerations for future pharmacological interventions to delay the onset of type 2 diabetes. They conclude with descriptions of some innovative, pragmatic translational initiatives already under way around the world.

Sulfone-stabilized carbanions for the reversible covalent capture of a posttranslationally-generated cysteine oxoform found in protein tyrosine phosphatase 1B (PTP1B)

Redox regulation of protein tyrosine phosphatase 1B (PTP1B) involves oxidative conversion of the active site cysteine thiolate into an electrophilic sulfenyl amide residue. Reduction of the sulfenyl amide by biological thiols regenerates the native cysteine residue. Here we explored fundamental chemical reactions that may enable covalent capture of the sulfenyl amide residue in oxidized PTP1B. Various sulfone-containing carbon acids were found to react readily with a model peptide sulfenyl amide via attack of the sulfonyl carbanion on the electrophilic sulfur center in the sulfenyl amide. Both the products and the rates of these reactions were characterized. The results suggest that capture of a peptide sulfenyl amide residue by sulfone-stabilized carbanions can slow, but not completely prevent, thiol-mediated generation of the corresponding cysteine-containing peptide. Sulfone-containing carbon acids may be useful components in the construction of agents that knock down PTP1B activity in cells via transient covalent capture of the sulfenyl amide oxoform generated during insulin signaling processes.

Effects of gliclazide add on metformin on serum omentin-1 levels in patients with type 2 diabetes mellitus

BACKGROUND

Omentin is a newly identified adipokine that has beneficial influence against cardiovascular disorders. Hence, considering the impact of anti-diabetic drug on omentin levels may provide an adjuvant strategy to protect diabetic patients against valuable clinical hazards.

AIM OF THE STUDY

To investigate the influence of metformin alone or in combination with gliclazide on the level of serum omentin among patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

A total of 70 newly diagnosed patients with T2DM were enrolled in this randomized, double-blind prospective study, and divided into two equal groups based on treatment regimen in which Group 1 treated with metformin (1000 mg) and Group 2 treated with metformin (1000 mg) plus gliclazide (80 mg). Blood glucose levels, HbA1C, insulin levels, and serum omentin-1 were measured at baseline and after 12 weeks of treatment.

RESULT

Use of gliclazide as an add-on therapy to metformin in patients with T2DM result in better glycemic control evidenced by significant reductions in the levels of blood glucose levels and HbA1C and much more improvement in insulin sensitivity evidenced by significant decreased in insulin resistance index, whereas it has adverse impact on serum omentin-1 levels evidenced by significant decrement in omentin-1 level in comparison to their pretreatment levels among Group 2 patients.

CONCLUSIONS

Adding of gliclazide to metformin in treatment of patients with T2DM might extend the therapeutic action of metformin in regarding much better controlling of glycemic indices, but, at the same time, it might attenuate the cardioprotective effects of metformin by its adverse influence on serum omentin-1 levels.

Prevention of type 2 diabetes in obese at-risk subjects: a systematic review and meta-analysis

Different intervention strategies can prevent new cases of type 2 diabetes (T2DM) in obese subjects. The present systematic review and meta-analysis evaluates the effectiveness of different strategies in prevention of type 2 diabetes in obese subjects. Studies were grouped into five different strategies: (1) physical activity ± diet; (2) anti-diabetic drugs (glitazones, metformin, glinides, alfa-glucosidase inhibitors); (3) antihypertensive drugs (ACE inhibitors, ARB); (4) weight loss-promoting drugs and lipid-lowering drugs (orlistat, bezafibrate, phentermine/topiramate controlled release); and (5) bariatric surgery. Only controlled studies, dealing with subjects BMI ≥ 30 kg/m(2), were included in the analysis, whether randomized or non-randomized studies. Appropriate methodology (PRISMA statement) was adhered to. Publication bias was formally assessed. Eighteen studies (43,669 subjects, 30,774 with impaired glucose tolerance and/or impaired fasting glucose), published in English language as full papers, were analyzed to identify predictors of new cases of T2DM and were included in a meta-analysis (random-effects model) to study the effect of different strategies. Intervention effect (new cases of diabetes) was expressed as odds ratio (OR), with 95 % confidence intervals (CIs). In obese subjects, non-surgical strategies were able to prevent T2DM, with different effectiveness [OR from 0.44 (0.36-0.52) to 0.86 (0.80-0.92)]; in morbidly obese subjects, bariatric surgery was highly effective [OR = 0.10 (0.02-0.49)]. At meta-regression analysis, factors associated with effectiveness were weight loss, young age and fasting insulin levels. Publication bias was present only when considering all studies together. These data indicate that several strategies, with different effectiveness, can prevent T2DM in obese subjects.

Progression from impaired fasting glucose to type 2 diabetes mellitus among Chinese subjects with and without hypertension in a primary care setting

BACKGROUND

The progression from impaired fasting glucose (IFG) to type 2 diabetes mellitus (T2DM) in Chinese subjects, with and without hypertension, in a primary care setting was unknown.

METHODS

The present retrospective multicenter 5-year (2002-2007) cohort study was performed on IFG subjects attending 23 general outpatient clinics who were identified by their elevated fasting blood glucose laboratory results. Development of T2DM was determined by physician diagnosis of T2DM or starting of oral antidiabetic drugs within 5 years. The relationship between the time of T2DM diagnosis and subject characteristics was assessed by adjusted hazard ratios (aHR) from Cox hazards model.

RESULTS

Of the 9161 IFG subjects, 4080 (45%) were men and 5081 (55%) were women. There were 1998 subjects who developed T2DM. The 5-year cumulative incidence was 0.218, whereas the overall annual incidence rate was 5.981/100 person-years. Subjects were more likely to develop T2DM if they were hypertensive (aHR = 1.44; 95% confidence interval [CI] 1.28-1.62; P < 0.001), aged <60 years (aHR = 1.36, 95% CI 1.24-1.49; P < 0.001), female (aHR = 1.18, 95% CI 1.08-1.29; P < 0.001), and had higher fasting glucose levels (6.39 ± 0.49 vs 6.24 ± 0.43 mmol/L in the group that developed T2DM vs the group without T2DM, respectively; aHR = 2.01, 95% CI 1.83-2.20; P < 0.001).

CONCLUSION

Overall, more than one-fifth of IFG subjects in the primary care setting developed T2DM within 5 years. Health care professionals can target interventions to patients with risk factors for disease progression.

Prevention of type 2 diabetes; a systematic review and meta-analysis of different intervention strategies

AIM

Different intervention strategies can prevent type 2 diabetes (T2DM). Aim of the present systematic review and meta-analysis was to evaluate the effectiveness of different strategies.

METHODS

Studies were grouped into 15 different strategies: 1: diet plus physical activity; 2: physical activity; 3-6: anti-diabetic drugs [glitazones, metformin, beta-cell stimulating drugs (sulphanylureas, glinides), alfa-glucosidase inhibitors]; 7-8: cardiovascular drugs (ACE inhibitors, ARB, calcium antagonists); 9-14 [diets, lipid-affecting drugs (orlistat, bezafibrate), vitamins, micronutrients, estrogens, alcohol, coffee]; 15: bariatric surgery. Only controlled studies were included in the analysis, whether randomized, non-randomized, observational studies, whether primarily designed to assess incident cases of diabetes, or performed with other purposes, such as control of hypertension, of ischemic heart disease or prevention of cardiovascular events. Appropriate methodology [preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement] was used. Seventy-one studies (490 813 subjects), published as full papers, were analysed to identify predictors of new cases of T2DM, and were included in a meta-analysis (random-effects model) to study the effect of different strategies. Intervention effect (new cases of diabetes) was expressed as odds ratio (OR), with 95% confidence intervals (C.I.s). Publication bias was formally assessed.

RESULTS

Body mass index was in the overweight range for 13 groups, obese or morbidly obese in lipid-affecting drugs and in bariatric surgery. Non-surgical strategies, except for beta-cell stimulating drugs, estrogens and vitamins, were able to prevent T2DM, with different effectiveness, from 0.37 (C.I. 0.26-0.52) to 0.85 (C.I. 0.77-0.93); the most effective strategy was bariatric surgery in morbidly obese subjects [0.16 (C.I. 0.11,0.24)]. At meta-regression analysis, age of subjects and amount of weight lost were associated with effectiveness of intervention.

CONCLUSIONS

These data indicate that several strategies prevent T2DM, making it possible to make a choice for the individual subject.

A marriage of two "Methusalem" drugs for the treatment of psoriasis?: Arguments for a pilot trial with metformin as add-on for methotrexate

In this article we present arguments that the “antidiabetic” drug metformin could be useful as an add-on therapy to methotrexate for the treatment of psoriasis and, perhaps, for rheumatoid arthritis as well. Biochemical data suggest that both drugs may share a common cellular target, the AMP-activated protein kinase (AMPK). This enzyme is a master regulator of metabolism and controls a number of downstream targets, e.g., important for cellular growth or function in many tissues including T-lymphocytes. Clinical observations as well as experimental results argue for anti-inflammatory, antineoplastic and antiproliferative activities of metformin and a case-control study suggests that the drug reduces the risk for psoriasis.

Patients with psoriasis have higher risk of metabolic syndrome, type 2 diabetes and cardiovascular mortality. Metformin has proven efficacy in the treatment of prediabetes and leads to a pronounced and sustained weight loss in overweight individuals. We expect that addition of metformin to methotrexate can lead to positive effects with respect to the PASI score, reduction of the weekly methotrexate dose and of elevated cardiovascular risk factors in patients with metabolic syndrome and psoriasis. For reasons explained later we suggest that only male, overweight patients are to be included in a pilot trial. On the other side of the coin are concerns that the gastrointestinal side effects of metformin are intolerable for patients under low dose, intermittent methotrexate therapy. Metformin has another side effect, namely interference with vitamin B₁₂ and folate metabolism, leading to elevated homocysteine serum levels. As patients must receive folate supplementation and will be controlled with respect to their B₁₂ status increased hematological toxicity is unlikely to result.

The reality of type 2 diabetes prevention

Efforts to reduce the burden of type 2 diabetes include attempts to prevent or delay the onset of the disease. Landmark clinical trials have shown that lifestyle modification programs focused on weight loss can delay the onset of type 2 diabetes in subjects at high risk of developing the disease. Building on this knowledge, many community-based studies have attempted to replicate the trial results and, simultaneously, payers have begun to cover diabetes prevention services. This article focuses on the evidence supporting the premise that community prevention efforts will be successful. Unfortunately, no study has shown that diabetes can be delayed or prevented in a community setting, and efforts to replicate the weight loss achieved in the trials have been mostly disappointing. Furthermore, both the clinical trials and the community-based prevention studies have not shown a beneficial effect on any diabetes-related clinical outcome. While the goal of diabetes prevention is extremely important, the absence of any persuasive evidence for the effectiveness of community programs calls into question whether the use of public funds or national prevention initiatives should be supported at this time.