Thiazolidinediones and Insulin

To Investigate the Potential Mechanism of Huanglian Jiangtang Formula Lowering Blood Sugar in View of Network Pharmacology and Molecular Docking Technology

Objective

In view of network pharmacology and molecular docking technology, to explore the targets as well as effect mechanism of the Huanglian Jiangtang formula (including Coptis chinensis, Anemarrhena asphodeloides, rhubarb wine, Cortex Moutan, Rehmannia glutinosa, and dried ginger) in the type II diabetes therapy.

Methods

TCMSP and Batman database (DB) were used to retrieve the chemical components and action targets of drugs; GeneCards, OMIM, TTD, DrugBank, and other databases were applied to screen the disease targets. We used the UniProt DB to annotate the targets before building the drug-compound-target network with Cytoscape 3.9.1. We also exploited the String DB to construct the protein-protein interaction (PPI) network. In addition, the targets for the treatment of type II diabetes were searched in the DrugBank, OMIM, GeneCards, and TTD database; then, we utilized Venn to intersect the key targets for the therapy of type II diabetes and active ingredient targets to obtain common targets. Furthermore, we exploited the common targets using GO and KEGG enrichment analysis method. The common targets and core components were analyzed by molecular docking using the AutoDock software.

Results

A total of 61 effective components of this compound were screened out; drugs and type II diabetes have 278 common targets; the PPI network screened core target proteins such as CDKN1A, CDK2, and E2F1 with the help of molecular docking technology; the three main compounds including quercetin, kaempferol, and gamma-aminobutyric acid were obtained. Besides, the key target proteins had excellent binding properties with the main components. The signal pathways of six compound interventions in type II diabetes were mostly related to cancer, cocaine addiction, aminoacyl-tRNA biosynthesis, glycine, serine, threonine metabolism, platinum drug resistance, and other pathways, according to the KEGG enrichment analysis method.

Conclusion

In the treatment of diabetes, the Huanglian Jiangtang formula has sorts of properties especially in the aspects of composition, target, and pathway. Its molecular target and mechanism of action may be related to pathways in cancer, cocaine addiction, aminoacyl-tRNA biosynthesis, glycine, serine, threonine metabolism, platinum drug resistance, and other pathways. This conclusion can provide theoretical support and science for further research.

The effects of soy isoflavone on insulin sensitivity and adipocytokines in insulin resistant rats administered with high-fat diet

The effects of soy isoflavone (SIF) on insulin sensitivity and adipocytokines in high-fat-diet-induced insulin resistant (IR) rats were studied. Male Sprague Dawley rats (n = 80) were randomly assigned into a basal diet fed group and high-fat diet fed group. The high-fat-diet-induced IR rats were assigned into IR model control group and three SIF-treated groups with different dosages. Thirty days later, the fasting blood glucose, insulin and adipocytokines in serum and mRNA expressions of adipocytokines in perirenal white adipose tissue were measured. The Homeostasis Model Assessment of IR was calculated. The administration of 450 mg kg(-1) d(-1) SIF decreased the body weights and depositions of visceral adipose tissue as well as improved insulin resistance in high-fat-diet-induced IR rats. The mechanisms were associated with SIF regulating the expression of adipocytokines, including adiponectin, leptin, resistin and TNF-alpha. SIF supplements may have favourable effects on insulin resistance in high-fat-diet-induced IR rats.

Intensification of oxidative stress and inflammation in type 2 diabetes despite antihyperglycemic treatment

INTRODUCTION

The metabolic deregulation associated with diabetes mellitus (DM) causes secondary pathophysiologic changes in multiple organ systems. Endothelial injury is induced by oxidative stress (OS) and inflammation. We have previously shown that DM type 2 patients are exposed to increased OS and inflammation contributed in part by primed peripheral polymorphonuclear leukocytes (PMNLs).

AIMS

To characterize the effect of oral medication on PMNL priming, on PMNL-related and on systemic inflammation, in correlation to changed diabetes parameters in patient with newly diagnosed type 2 DM.

METHODS

PMNLs were separated from DM patient's prior and following treatment with either metformin (Glucophage), or Thiazolidinedione (rosiglitazone) and from healthy control subjects (HC). Rate of superoxide release from phorbol ester-stimulated PMNLs and CD11b on PMNLs assessed PMNL priming. White blood cells (WBC) and PMNL counts and apoptosis reflected PMNL-related inflammation. CRP, fibrinogen, transferrin and albumin blood levels reflected systemic inflammation.

RESULTS

Both metformin and rosiglitazone treatments reduced significantly the high levels of glucose and HbA1c, and slightly improved lipid profile during 2 months. PMNL priming parameters, higher compared to HC, increased after 2 months of metformin treatment. Rosiglitazone treatment decreased PMNL priming. ALP, higher in DM, significantly decreased following 2 months of both treatments. Systemic inflammation markers (fibrinogen, CRP), higher in DM, decreased following both treatments. Transferrin and albumin were similar to HC. PMNL-related inflammation markers were higher in DM; however, only PMNL apoptosis decreased after both treatments. Monocyte counts, higher in DM compared to HC, decreased following both treatments. Serum insulin levels, higher in DM compared to HC, decreased following both treatments. PMNL-related priming and inflammation parameters positively correlated with HbA1c.

CONCLUSION

The present research adds new facet in evaluating anti-hyperglycemic treatment in type 2 DM patients. Despite sufficient glycemic control using both treatments, some PMNL-related parameters deteriorated. Thus, anti hyperglycemic treatment should be favored due to its combined anti-PMNL priming and anti-inflammatory effect, in addition to its anti-hyperglycemic characteristics, according to the correlation among these parameters. Such combined treatment may reduce morbidity and mortality common in DM patients.

[Types of insulin therapy]

Diabetes mellitus is a chronic disease associated with a series of long-term microvascular and macrovascular complications that requires continuing therapeutic control. In recent years, the pharmaceutical industry has developed new types of insulin and administration systems in order to more closely mimic human insulin secretion. In this way, insulin therapy is divided into conventional and intensive regimens according to their complexity. In type 1 diabetes mellitus (T1DM) patients, the treatment of choice is the one which achieves intensive glycemic control. In type 2 diabetes mellitus, we can start with a simplified conventional regimen which could progress into an intensive one similar to that of T1DM treatment. Both types of diabetes require an individualized treatment prescription based on the needs and characteristics of each patient.

Why insulin sensitizers but not secretagogues should be retained when initiating insulin in type 2 diabetes

The stringent targets set for HbA(1c) levels in type 2 diabetes are currently achieved by fewer than half the patients in the United States. Failure to manage hyperglycaemia in the early stages of disease results in progressive loss of beta-cell function, which ultimately necessitates the initiation of insulin therapy. At this point, choices have to be made on whether to continue oral anti-diabetic drug therapy and, if so, with which agent(s). Historically, sulfonylureas have been the mainstay of oral anti-diabetic drug therapy; however, their long-term efficacy in patients with depleted beta-cell capacity is doubtful, and other classes of oral anti-diabetic drugs, notably the insulin sensitizers, may prove more reliable. These agents (metformin and thiazolidinediones) appear to provide various benefits over and above sustained glycaemic control, which may variably include reduced loss of beta-cell function as well as improvements to cardiovascular risk factors, morbidity, and mortality. Metformin also limits weight gain associated with insulin therapy. This manuscript presents the case that when insulin therapy is initiated it should be tailored to individual needs through combination with one or more insulin sensitizers rather than a secretagogue.

Comparison of insulin monotherapy and combination therapy with insulin and metformin or insulin and rosiglitazone or insulin and acarbose in type 2 diabetes

The aim of this study was to compare the efficacy of treatment with insulin alone, insulin plus acarbose, insulin plus metformin, or insulin plus rosiglitazone in type 2 diabetic subjects who were previously on insulin monotherapy, and to evaluate the effects of these treatments on cardiovascular risk factors including lipid profile, C-reactive protein (CRP) and fibrinogen. Sixty-six poorly controlled type 2 diabetic patients on insulin monotherapy were involved. They were randomized to insulin alone, insulin plus acarbose, insulin plus metformin, or insulin plus rosiglitazone groups for 6 months period. Mean fasting and postprandial glucose values as well as HbA1c levels significantly decreased in all groups. The greatest improvement in HbA1c was observed in insulin plus rosiglitazone (2.4%) and in insulin plus metformin (2%) groups. Daily total insulin dose was increased to 12.7 units/day in insulin alone group, decreased to 4.7 units/day in insulin plus rosiglitazone group, to 4.2 units/day in insulin plus metformin group, and to 2.7 units/day in insulin plus acarbose group. Least weight gain occurred in insulin plus metformin group (1.4 kg) and greatest weight gain occurred in insulin plus rosiglitazone group (4.6 kg). No significant change in lipid levels--except serum triglycerides--was observed in any groups. CRP and fibrinogen levels decreased in all groups, but the decrease in fibrinogen level was significantly greater in insulin plus rosiglitazone group. All groups were comparable in hypoglycemic episodes. No serious adverse event was noted in any group.

Why, when and how to initiate insulin therapy in patients with type 2 diabetes

Type 2 diabetes is characterised by insulin resistance and progressive beta-cell deterioration. As beta-cell function declines, most patients with type 2 diabetes will require insulin therapy. Clinical studies show that tight control of blood glucose levels prevents the development of the microvascular and macrovascular complications caused by diabetes. Insulin is the most potent drug currently available to achieve tight glycaemic control; however, often it is not used early or aggressively enough for patients to achieve the glycaemic targets needed to prevent chronic complications. New basal insulin analogues and premixed insulin analogues, which have more physiological time-action profiles compared with human insulin formulations, offer flexibility and convenience, thereby improving quality of life. It is crucial that doctors initiate insulin therapy as soon as other diabetes therapies are no longer effective. This article reviews the improvements provided by basal insulin analogues, premixed insulin analogues, and insulin delivery systems; provides sample algorithms for initiating and titrating the various insulin analogue preparations; and discusses how to individualise treatment regimens to maximise outcomes in patients with type 2 diabetes.

Biphasic Insulin Aspart in Type??2??Diabetes Mellitus

The efficacy benefits of biphasic insulin aspart formulation (BIAsp 30) in patients with diabetes mellitus have been reported in several studies. BIAsp 30 has been shown to be more effective in terms of glycaemic control than standard biphasic human insulin 30 (BHI 30). In addition to gauging the treatment in terms of clinical evidence of benefits provided, it is also important to evaluate the strength of the evidence supporting the therapeutic improvements offered by BIAsp 30. In this paper, we evaluated the strength of the available data that relate to the use of BIAsp 30 in the treatment of patients with type 2 diabetes based on a comprehensive literature review. Selected publications that provided relevant data were obtained via a literature search and from the manufacturer, Novo Nordisk. These were graded in terms of the strength of the evidence they provided using the Oxford Centre for Evidence-Based Medicine (CEBM) system in the following categories: (i) twice-daily use versus basal insulin; (ii) twice-daily use versus other treatments; (iii) once-daily use; (iv) thrice-daily use; (v) use in combination with thiazolidinediones; and (vi) use in comparison with BHI 30. A total of 30 publications for BIAsp 30 were identified and graded. For the majority of categories (four out of six), the evidence supporting the use of BIAsp 30 was given an overall CEBM grade of A (highest quality); evidence supporting clinical efficacy in the other two categories (twice-daily use versus basal insulin and thrice-daily BIAsp 30 administration) was graded B. In most of the studies examined, the efficacy of BIAsp 30 was evaluated in terms of glycaemic control (glycosylated haemoglobin [HbA(1c)] reduction, proportion of patients achieving HbA(1c) target of <6.5% or <7%, fasting blood glucose, blood glucose profile and/or prandial and postprandial glucose increments). In some studies, efficacy was further evaluated using plasma insulin and glucose infusion rates, plasma C-peptide levels, mean serum fructosamine levels, postprandial hyperlipidaemia, overall well-being, treatment satisfaction and quality of life. Safety was evaluated using physical and laboratory investigations and assessment of incidence of adverse events, including, in many of the studies reviewed, specific evaluation of those events known to be associated with antidiabetic treatment, hypoglycaemia and weight gain. Strong evidence was provided for better glycaemic control with BIAsp 30 without increases in the incidence of major hypoglycaemia or nocturnal hypoglycaemic episodes. Overall, weight gain with BIAsp 30 was minimal and not significantly greater than with basal insulin or BHI 30. Thus, we can confirm that the reported efficacy and tolerability of BIAsp 30 in the treatment of diabetes based on a variety of clinical endpoints is supported by a good body of evidence relating to its use in different dosage regimens and in comparison with other insulin treatment regimens.

Basal insulin or premix analogue therapy in type 2 diabetes patients

BACKGROUND

We sought to compare the safety and efficacy of biphasic insulin aspart 30 (BIAsp 30) given twice daily with once-daily insulin glargine in patients with type 2 diabetes beginning insulin therapy and who did not use thiazolidinediones, which are contraindicated with insulin in the European Union, in a subpopulation (N=157) of the INITIATE study.

METHODS

At baseline, HbA(1c) was >/=8.0% on >/=1000 mg/day metformin alone or in combination with other oral antidiabetic drugs (OADs; e.g. sulphonylurea or alpha-glucosidase inhibitors). Metformin was adjusted up to 2550 mg/day and other OADs were discontinued. Starting insulin doses were subsequently adjusted weekly for 26 weeks by algorithm-directed titration.

RESULTS

The proportion of patients achieving a HbA(1c) below 7.0% at 28 weeks was greater with BIAsp 30 than with insulin glargine (65% vs 41%, P=0.003). The mean reduction in HbA(1c) was greater for BIAsp 30 than for insulin glargine: -2.89+/-1.6% vs -2.46+/-1.6%, respectively (P=0.035). Postprandial glucose increments were lower for the BIAsp 30 group after breakfast (P=0.003) and dinner (P=0.033); post-lunch values were not significantly different. No major hypoglycemic episodes were recorded. Nocturnal hypoglycemia was reported by 25% of subjects in the BIAsp 30 group and by 10% in the insulin glargine group (P=0.021). Weight gain was 5.6+/-4.6 and 3.0+/-4.3 kg (P=0.0004) for BIAsp 30 and insulin glargine, respectively.

CONCLUSIONS

BIAsp 30, given twice daily in combination with metformin, was more effective than insulin glargine, given once daily in combination with metformin, at controlling blood glucose in insulin-naïve patients with type 2 diabetes, but was associated with increased weight gain and minor hypoglycemic events.

Peroxisome proliferator-activated receptor gamma as a drug target in the pathogenesis of insulin resistance

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that belong to the nuclear hormone receptor superfamily. The activation of PPAR-gamma, an isotype of PPARs, can either increase or decrease the transcription of target genes. The genes controlled by this form of PPAR have been shown to encode proteins or peptides that participate in the pathogenesis of insulin resistance. Insulin resistance is defined as a state of reduced responsiveness to normal circulating concentrations of insulin and it often co-exists with central obesity, hypertension, dyslipidemia, and atherosclerosis. There is substantial evidence that links obesity with insulin resistance and type-2 diabetes. The early phase of obesity-related insulin resistance has 2 components: (a) interruption of lipid homeostasis leading to the increased plasma concentration of fatty acids that is normally suppressed by the activation of PPAR-gamma, and (b) activation of factors such as cytokines depressed by PPAR-gamma that cause insulin resistance. Therefore, it is logical to suggest that activation of PPAR-gamma may partially reverse the state of insulin resistance. Evidently, activation of the nuclear receptor, PPAR-gamma, by thiazolidinediones has been reported to ameliorate insulin resistance. Although hepatotoxity and possibility to induce congestive heart failure (CHF) limit the widely use of thiazolodinediones, they are still powerful weapon to fight against insulin resistance and type-2 diabetes if use properly. This article reviews the physiology of PPAR-gamma and insulin-signaling transduction, the pathogenesis of insulin resistance in obesity-related type-2 diabetes, the pharmacological role of PPAR-gamma in insulin resistance, and additional effects of thiazolidinediones.