Covalent organic framework based cytoprotective therapy after ischemic stroke

Cytoprotection has emerged as an effective therapeutic strategy for mitigating brain injury following acute ischemic stroke (AIS). The sulfonylurea receptor 1-transient receptor potential M4 (SUR1-TRPM4) channel plays a pivotal role in brain edema and neuroinflammation. However, the practical use of the inhibitor glyburide (GLB) is hindered by its low bioavailability. Additionally, the elevated reactive oxygen species (ROS) after AIS exacerbate SUR1-TRPM4 activation, contributing to irreversible brain damage. To overcome these challenges, GLB and superoxide dismutase (SOD) were embedded in a covalent organic framework (COF) with a porous structure and great stability. The resulting S/G@COF demonstrated significant improvements in survival and neurological functions. This was achieved by eliminating ROS, preventing neuronal loss and apoptosis, suppressing neuroinflammation, modulating microglia activation, and ameliorating blood-brain barrier (BBB) disruption. Mechanistic investigations revealed that S/G@COF concurrently activated the Wnt/β-catenin signaling pathway while suppressing the upregulation of SUR1-TRPM4. This study underscores the potential of employing multi-target therapy and drug modification in cytoprotective strategies for ischemic stroke.

Glyburide-treated human monocyte-derived dendritic cells loaded with insulin represent tolerogenic features with anti-inflammatory responses and modulate autologous T cell responses in vitro

Tolerogenic dendritic cells (TolDCs) are attractive therapeutic options for autoimmune disorders because they suppress autologous T-cell responses. Dendritic cells (DCs) are equipped with pattern recognition receptors (PRR), including nucleotide-binding and oligomerization domain-like receptors (NLRs) such as NLRP3. Abnormal NLRP3 activation has been reported to be correlated with the occurrence of autoimmune disorders. Accordingly, we hypothesized that glyburide treatment of DCs by blocking the ATP-sensitive K+ (kATP) channels generates TolDCs by inhibiting NLRP3. Insulin was even loaded on a group of glyburide-treated mature DCs (mDCs) to investigate the antigen (Ag) loading effects on glyburide-treated mDCs' phenotypical and functional features. Consequently, T lymphocytes' mediated responses ensuing co-culture of them with control mDCs, insulin loaded and unloaded glyburide treated mDCs were evaluated to determine generated TolDCs' capacity in inhibition of T cell responses that are inducer of destruction in insulin-producing pancreatic beta cells in Type 1 Diabetes Mellitus (T1DM). Our findings indicated that glyburide generates desirable TolDCs with decreased surface expression of maturation and Ag presentation related markers and diminished level of inflammatory but increased level of anti-inflammatory cytokines, which even insulin loading demonstrated more anti-inflammatory functions. In addition, co-cultured T cells showed regulatory or T helper 2 phenotype instead of T helper 1 features. Our findings suggested that insulin-loaded and unloaded glyburide-treated DCs are promising therapeutic approaches for autoimmune patients, specifically DCs loaded with insulin for T1DM patients. However, further research is required before this technique can be applied in clinical practice.

Evaluation of a microphysiological human placental barrier model for studying placental drug transfer

Understanding drug transport across the placental barrier is important for assessing the potential fetal drug toxicity and birth defect risks. Current in vivo and in vitro models have structural and functional limitations in evaluating placental drug transfer and toxicity. Microphysiological systems (MPSs) offer more accurate and relevant physiological models of human tissues and organs on a miniature scale for drug development and toxicology testing. MPSs for the placental barrier have been recently explored to study placental drug transfer. We utilized a multilayered hydrogel membrane-based microphysiological model composed of human placental epithelial and endothelial cells to replicate the key structure and function of the human placental barrier. A macroscale human placental barrier model was created using a transwell to compare the results with the microphysiological model. Placental barrier models were characterized by assessing monolayer formation, intercellular junctions, barrier permeability, and their structural integrity. Three small-molecule drugs (glyburide, rifaximin, and caffeine) that are prescribed or taken during pregnancy were studied for their placental transfer. The results showed that all three drugs crossed the placental barrier, with transfer rates in the following order: glyburide (molecular weight, MW = 494 Da) < rifaximin (MW = 785.9 Da) < caffeine (MW = 194.19 Da). Using non-compartmental analysis, we estimated human pharmacokinetic characteristics based on in vitro data from both MPS and transwell models. While further research is needed, our findings suggest that MPS holds potential as an in vitro tool for studying placental drug transfer and predicting fetal exposure, offering insights into pharmacokinetics.

Medications for Managing Preexisting and Gestational Diabetes in Pregnancy

Persons with gestational and pregestational diabetes during pregnancy may require pharmacologic agents to achieve pregnancy glycemic targets, and the available medications for use in pregnancy are limited. Insulin is the only FDA-approved medication for use in pregnancy and has the greatest evidence for safety and efficacy. Metformin and glyburide are the most commonly used oral agents in pregnancy. Understanding each medication's unique pharmacokinetics, potential side effects, fetal or childhood risks, gestational age of medication initiation and patient's diabetes care barriers are important aspects of shared decision-making and choosing a regimen that will achieve glycemic and pregnancy goals.

In vivo pharmacokinetic analyses of placental transfer of three drugs of different physicochemical properties in pregnant rats

Although the use of medication during pregnancy is common, information on exposure to the developing fetus and potential teratogenic effects is often lacking. This study used a rat model to examine the placental transfer of three small-molecule drugs with molecular weights ranging from approximately 300 to 800 Da with different physicochemical properties. Time-mated Sprague Dawley (Hsd:SD) rats aged 11-13 weeks were administered either glyburide, rifaximin, or fentanyl at gestational day 15. Maternal blood, placentae, and fetuses were collected at 5 min, 30 min, 1 h, 4 h, 8 h, 24 h, 48 h, and 96 h post-dose. To characterize the rate and extent of placental drug transfer, we calculated several pharmacokinetic parameters such as maximum concentration (Cmax), time to maximum concentration (Tmax), area under the concentration-time curve (AUC), half-life (t_1/2), clearance (CL), and volume of distribution (Vd) for plasma, placenta, and fetus tissues. The results indicated showed that fetal exposure was lowest for glyburide, accounting for only 2.2 % of maternal plasma exposure as measured by their corresponding AUC ratio, followed by rifaximin (37.9 %) and fentanyl (172.4 %). The fetus/placenta AUC ratios were found to be 10.7 % for glyburide, 11.8 % for rifaximin, and 39.1 % for fentanyl. These findings suggest that although the placenta acts as a protective shield for the fetus, the extent of protection varies for different drugs and depends on factors such as molecular weight, lipid solubility, transporter-mediated efflux, and binding to maternal and fetal plasma proteins.

Formulation development, in-vitro characterization and bioavailability studies

The co-formulation of glyburide (Gly) and vanillic acid (VA) as such in the form of nanomedicine has never been explored to treat metabolic diseases including type 2 diabetes mellitus. Both the drugs possess dissolution rate-limited oral bioavailability leading to poor therapeutic efficacy. Hence, co-loading these drugs into a nanocarrier could overcome their poor oral bioavailability related challenges. Owing to this objective, both drugs were co-loaded in amphiphilic polymeric micelles (APMs) and evaluated for their biopharmaceutical outcomes. The APMs were prepared using mPEG-b-PCL/CTAB as a copolymer-surfactant system via the liquid antisolvent precipitation (LAP) method. The design of these APMs were optimized using Box Behnken Design by taking various process/formulation based variables to achieve the desired micellar traits. The release of both the drugs from the optimized co-loaded APMs was compared in different media and displayed a remarkable sustained release profile owing to their hydrophobic interactions with the PCL core. The in vitro cytotoxicity study of co-loaded APMs on Caco-2 cells revealed 70 % cell viability in a concentration-dependent manner. The preventive effects of Gly and VA co-loaded in APMs on glucose uptake was studied in insulin-responsive human HepG2 cells treated with high glucose. The co-loading of both the drugs in optimized APMs exhibited synergistic glucose-lowering activity (p < 0.001) than raw drugs with low cytotoxicity on HepG2 cells within the test concentration. This could be attributed to an increase in the relative oral bioavailability of both the drugs in APMs i.e., 868 % for Gly and 87 % for VA respectively.

Fustin ameliorates hyperglycemia in streptozotocin induced type-2 diabetes via modulating glutathione/Superoxide dismutase/Catalase expressions, suppress lipid peroxidation and regulates histopathological changes

Streptozotocin (STZ) 60 mg/kg, i.p.-induced diabetes in rat’s results into hyperglycemia, impaired oxidative stress, lipid profile, insulin levels and changes in body weight. Treatment with antihyperglycemics and antioxidants are accounted to produce favorable effect in this paradigm. Fustin, a flavonoid derived from Rhus verniciflua, extract of Rhus verniciflua reported to exhibit anti-hyperglycemic, antioxidant, anti-microbial, anti-arthritic effects, anti-obesity effects, antiplatelet effects and anti-cancer effects. However, no evidence is existing on effect of fustin on STZ-induction diabetes. Thus, we evaluated its effects against diabetes in STZ-induced rodents. Blood glucose, Insulin, lipid peroxidation (MDA), superoxide dismutase (SOD), catalase activity (CAT), glutathione (GSH) and lipid profile levels was assessed. After 30 days diabetes induction rodents showed a severe increased blood sugar level, MDA, high density lipid and decreased cholestrol, triglyceride, GSH, SOD, CAT, respectively.

Oppositely, treatment with fustin (50–100 mg/kg/p.o., two times daily, 30 days) enhanced blood glucose, lipid profile levels Insulin. Meanwhile, reduced MDA and enhanced GSH, SOD, and CAT in diabetic rats. Glibenclamide 5 mg/kg/p.o. also enhanced diabetes-induced complications and decreased oxidative stress. Further histopathology of pancreas confirms the protective effect fustin in STZ-induction diabetes in animals. In conclusion, the study revealed treatments with fustin avoid the changes in body weight, blood glucose, lipid profile and oxidative stress. As a results of these finding may lead to the growth of a choice of medicine for hyperglycemic in the future.

Glycemic control and neonatal outcomes in women with gestational diabetes mellitus treated using glyburide, metformin, or insulin: a pairwise and network meta-analysis

AIMS

We aimed to assess the comparative efficiency and safety of the use of glyburide, metformin, and insulin in gestational diabetes mellitus (GDM).

METHODS

We searched for randomized controlled trials that compared glyburide, metformin, and insulin in GDM. Data regarding glycemic control and neonatal safety were collected and analyzed in pairwise and network meta-analyses.

RESULTS

A total of 4533 individuals from 23 trials were included. Compared with glyburide, metformin reduced 2-h postprandial blood glucose (2HPG) to a greater extent (standard mean difference (SMD) 0.18; 95% credible interval (CI) 0.01, 0.34). There were significantly lower prevalence of neonatal hypoglycemia (risk difference (RD) - 0.07; 95%CI - 0.11, - 0.02) and preeclampsia (RD - 0.03; 95%CI - 0.06, 0) in the metformin group than in the insulin group. The metformin group had significantly lower birth weight (SMD - 0.17; 95%CI - 0.25, - 0.08) and maternal weight gain (SMD - 0.61; 95%CI - 0.86,- 0.35) compared with the insulin group. Network meta-analysis suggested that metformin had the highest probability of successfully controlling glycemia and preventing neonatal complications.

CONCLUSIONS

The present meta-analysis suggests that metformin may be as effective as insulin for glycemic control and is the most promising drug for the prevention of neonatal and maternal complications.

Effects of Different Glucose-Lowering Measures on Maternal and Infant Outcomes in Pregnant Women with Gestational Diabetes: A Network Meta-analysis

INTRODUCTION

A network meta-analysis was conducted to compare and rank the effects of different glucose-lowering measures on maternal and infant outcomes in pregnant women with gestational diabetes mellitus (GDM).

METHODS

We searched the PubMed, CNKI, Embase, Cochrane Library, Wanfang, and Weipu databases for relevant studies published between database establishment and June 2021. Study retrieval involved subject-heading and keyword searches. Randomized controlled trials (RCTs) with different glucose-lowering treatments for GDM patients were included. The Cochrane tool was used to assess bias risk. Pairwise and network meta-analyses were used to compare and rank the effects of different hypoglycemic measures on maternal and infant outcomes in pregnant women with GDM.

RESULTS

We included 41 RCTs involving 6245 pregnant women with GDM. Patients treated with insulin had a higher incidence of neonatal intensive care unit (NICU) occupancy (1.3, 95% CI 1.0-1.7) than those treated with metformin. The insulin (1.5, 95% CI 1.1-2.1 and 1.8, 95% CI 1.0-3.3) and glyburide (2.0, 95% CI 1.2-3.2 and 2.5, 95% CI 1.1-8.4) groups exhibited higher incidences of neonatal hypoglycemia and large for gestational age (LGA) newborns than the metformin group. The glyburide group exhibited a lower probability of cesarean section than the metformin (0.76, 95% CI 0.55-1.0) and insulin (0.71, 95% CI 0.52-0.96) groups. Preeclampsia incidence in the diet and exercise groups was significantly lower than in the metformin (0.19, 95% CI 0.043-0.72) and insulin (0.15, 95% CI 0.032-0.52) groups. No intervention significantly reduced the incidences of macrosomia, preterm birth, gestational hypertension, or respiratory distress syndrome (RDS). The ranking results showed that the metformin group had the lowest rates of neonatal hypoglycemia, macrosomia, LGA, and NICU occupancy. The glyburide group had the lowest NICU occupancy and cesarean section rates and the highest neonatal hypoglycemia, LGA, preeclampsia, and gestational hypertension rates. The diet and exercise group had the lowest preterm delivery and preeclampsia rates and the highest NICU occupancy rate.

CONCLUSION

Metformin is a potentially superior choice for GDM treatment because it is associated with minimal incidences of multiple adverse pregnancy outcome indicators and does not lead to high values of certain adverse outcome indices. Other hypoglycemic agent or diet groups exhibit high incidences of certain adverse outcomes. Therefore, when selecting a GDM treatment strategy, the efficacies and risks of different treatment programs should be evaluated according to the scenario in hand.

Assessment of glibenclamide pharmacokinetics in poloxamer 407-induced hyperlipidemic rats

The aim of the present research was to describe the consequences of hyperlipidemia (HL) on the pharmacokinetics of glibenclamide (Gb) in poloxamer 407-induced hyperlipidemic rats. Rats were given intraperitoneal dose of poloxamer 407 to cause hyperlipidemia. A single oral dose of Gb (10 mg/Kg) was given to normal and HL rats. The C_max and t_max after oral dose of Gb in normal rats were 340.10 µg/ml and 3.67 h, respectively. Whereas, the C_max and t_max after oral dose of Gb in HL rats were noted as 773.39 µg/ml and 2.50 h respectively. The AUC value of Gb was found considerably higher in the HL rats. While the plasma clearance (CL) after oral dose of Gb was 2.53 ml/h and 1.39 ml/h in normal and HL rats respectively. The improved plasma concentration of Gb following oral dosing in rats with HL seems to be due to a direct influence on hepatic clearance or metabolizing enzymes. In conclusion, the Gb pharmacokinetics was considerably affected by the HL in rats. Such findings play an important role for predicting the alterations in the pharmacokinetics of drugs including GB, in cases having hyperlipidemia.

Comparison of Insulin, Metformin, and Glyburide on Perinatal Complications of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis

AIM

This systematic and meta-analysis was conducted to evaluate the efficacy and safety of insulin, metformin, and glyburide on perinatal complications for gestational diabetes mellitus (GDM).

METHODS

Medline (PubMed), EMBASE, The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials [CENTRAL], and Cochrane Methodology Register), Web of Science (Science and Social Science Citation Index), and ClinicalTrials (Clinicaltrials.gov) were searched, as well as manual searching. We included randomized controlled trials comparing efficacy and safety of metformin versus glyburide, metformin versus insulin, and glyburide versus insulin in patients with GDM.

RESULTS

We included 32 articles including 5,964 patients published from inception to July 2020. Compared with insulin, metformin was more effective at lower incidence of macrosomia (RR: 0.66, 95% CI: 0.50-0.88, p = 0.005), lower incidence of neonatal intensive care unit admission (RR: 0.78, 95% CI: 0.67-0.91, p = 0.002), less neonatal hypoglycemia (RR: 0.67, 95% CI: 0.56-0.80, p < 0.0001), decreased birth weight (BW) (SMD: -0.37, 95% CI: -0.62 to -0.12, p = 0.004), lower incidence of large for gestational age (RR: 0.76, 95% CI: 0.50-0.90, p = 0.002), shorter gestation age at delivery (MD: -0.22, 95% CI: -0.34 to -0.10, p = 0.0002), lower maternal weight gain (MD: -1.41, 95% CI: -2.28 to -0.55, p = 0.001), less incidence of caesarean section delivery (RR: 0.86, 95% CI: 0.78-0.95, p = 0.0004), lower maternal postprandial blood glucose (SMD: -0.41, 95% CI: -0.72 to -0.11, p = 0.008), and lower incidence of pregnancy-induced hypertension (RR: 0.47, 95% CI: 0.27-0.83, p = 0.01). However, glyburide, compared with insulin, was associated with higher BW (MD: 54.95, 95% CI: 3.87-106.03, p = 0.03) and increased the incidence of neonatal hypoglycemia (RR: 1.52, 95% CI: 1.12-2.07, p = 0.007). Meanwhile, compared to glyburide, metformin was associated with higher maternal fasting blood glucose (SMD: 0.20, 95% CI: 0.05-0.36, p = 0.01) and lower incidence of induction of labor (RR: 0.76, 95% CI: 0.59-0.97, p = 0.03).

CONCLUSIONS

This review suggests that metformin can decrease the incidence of perinatal complications, and it should be considered as a generally safe alternative to insulin.

BIIB093 (intravenous glibenclamide) for the prevention of severe cerebral edema

Background:

Vasogenic edema in the setting of acute ischemic stroke can be attributed to the opening of transient receptor potential 4 channels, which are expressed in the setting of injury and regulated by sulfonylurea receptor 1 (SUR1) proteins. Glibenclamide, also known as glyburide, RP-1127, Cirara, and BIIB093, is a second-generation sulfonylurea that binds SUR1 at potassium channels and may significantly reduce cerebral edema following stroke, as evidenced by recent clinical trials. This review provides a comprehensive analysis of clinical considerations of glibenclamide use and current patient outcomes when administered in the setting of acute ischemic stroke to reduce severe edema.

Methods:

National databases (MEDLINE, EMBASE, Cochrane, and Google scholar databases) were searched to identify studies that reported on the clinical outcomes of glibenclamide administered immediately following acute ischemic stroke.

Results:

The pharmacological mechanism of glibenclamide was reviewed in depth as well as the known indications and contraindications to receiving treatment. Eight studies were identified as having meaningful clinical outcome data, finding statistically significant differences in glibenclamide treatment groups ranging from matrix metalloproteinase-9 serum levels, midline shift, modified Rankin Scores, National Institute of Health Stroke Score, and mortality endpoints.

Conclusion:

Studies analyzing the GAMES-Pilot and GAMES-PR trials suggest that glibenclamide has a moderate, however, measurable effect on intermediate biomarkers and clinical endpoints. Meaningful conclusions are limited by the small sample size of patients studied.

Glyburide inhibits non-enzymatic glycation of HSA: An approach for the management of AGEs associated diabetic complications

Advanced glycation endproducts (AGEs) are the final product of glycation, highly reactive in nature and contribute directly or indirectly to numerous complications related to diabetes. In this study, the antiglycation activity of glyburide was investigated using HSA as model protein, both against glucose and methylglyoxal mediated glycation. The possible mechanism of action was also deciphered using biophysical and computational tools. Approximately 70% inhibition of both early and advanced glycation end products were recorded in the presence of glyburide. Free lysine modification was reduced by glyburide treatment and improvement in biochemical markers such as free thiol groups and carbonyl content was observed. Interaction studies revealed that glyburide showed moderate to strong binding affinity towards HSA with binding constant in the order of 10⁶ M^-1. The interaction of glyburide with HSA was entropically favourable and spontaneous in nature. Molecular dynamics simulation deciphered that glyburide-HSA complex was quite stable where RMSD, RMSF, R_g, SASA, and secondary structure of HSA remained approximately same over the entire simulation period. The average binding energy of the MD simulation for glyburide-HSA complex was found to be -15.386 kJ mol^-1. The findings demonstrate the antiglycation potential of glyburide and its possible mechanism of action.

Glyburide therapy for gestational diabetes: Glycaemic control, maternal hypoglycaemia, and treatment failure

AIMS

The recommended first-line treatment for women with gestational diabetes mellitus (GDM) in the case of failure of diet is insulin. Recent results suggest that there is a potential role for glyburide therapy and highlight the need for better knowledge of glycaemic control with glyburide. The objective of this study was to describe and quantify in women with GDM the quality of glycaemic control, including the risk of maternal hypoglycaemia and of therapy failure.

METHODS

This is a secondary analysis of the French INDAO non-inferiority trial from 2012 to 2016, in which 890 women with GDM randomized to receive glyburide or insulin treatment were compared for perinatal outcomes. Blood glucose concentrations were assessed prospectively during pregnancy. Optimal glycaemic control was defined as less than 20% of blood glucose values exceeding the targets.

RESULTS

More than 50% of the women had optimal glycaemic control with glyburide, similar to that with insulin. Around 40% of the women had at least one episode of hypoglycaemia, more than with insulin. However, those hypoglycaemic episodes were mostly moderate and the rate of severe hypoglycaemia decreased significantly during the course of the trial. Failure of glyburide treatment (switch to insulin therapy) occurred in 18% of women and had few predictors. However, when failure occurred, glycaemic control was improved after switching to insulin.

CONCLUSIONS

Glyburide is an effective treatment for reaching glycaemic goals during pregnancy in women with GDM. The risk of maternal hypoglycaemia may be minimized by clinical practice experience. These findings could be taken into account in the management of GDM.

Risk Factors for Hypoglycemia with the Use of Enteral Glyburide in Neurocritical Care Patients

OBJECTIVE

Intravenous glyburide has demonstrated safety when used for attenuation of cerebral edema, although safety data are lacking for enteral glyburide when used for this indication. We aimed to determine the prevalence of and risk factors for hypoglycemia in neurocritical care patients receiving enteral glyburide.

METHODS

We performed a retrospective case-control chart review (hypoglycemia vs. no hypoglycemia) of adult patients who received enteral glyburide for prevention or treatment of cerebral or spinal cord edema. Hypoglycemia was defined as a blood glucose <55.8 mg/dL. Descriptive statistics were used, with multivariate analysis to measure the association of risk factors and outcomes. Logistic regression was applied to outcomes with an exposure. Potential confounders were evaluated using the t-test or the Wilcoxon rank-sum test for continuous variables, and the χ² test or the Fisher exact test for categorical variables.

RESULTS

Seventy-one patients (60.6% men, median age 60 years) were included. The majority received 2.5 mg of enteral glyburide twice daily. Diagnoses included tumors (35.2%), intracerebral hemorrhage (28.2%), postspinal surgery (12.7%), and ischemic stroke (12.7%). Hypoglycemia occurred in 17 (23.9%) patients. Multivariate analysis identified admission serum creatinine (odds ratio, 27.2; [1.661, 445.3]; P < 0.05) as a risk factor for hypoglycemia, whereas body mass index >30 (odds ratio, 0.085; [0.008, 0.921]; P < 0.05) was protective.

CONCLUSIONS

Hypoglycemic episodes are common following enteral glyburide in neurocritical care patients. Both patients with and without diabetes mellitus are at risk of hypoglycemia. Elevated admission serum creatinine may increase the risk of hypoglycemia when utilizing glyburide for prevention or treatment of cerebral or spinal cord edema.

Characterization of women with gestational diabetes who failed to achieve glycemic control by lifestyle modifications

PURPOSE

To identify specific characteristics of women diagnosed with gestational diabetes who failed to achieve good glycemic control by lifestyle modifications only.

METHODS

Retrospective analysis of women carrying a singleton pregnancy diagnosed with gestational diabetes. The cohort included 314 women who achieved good glycemic control by lifestyle modifications and 328 women who required anti-diabetic medications. Lifestyle modifications included medical nutrition therapy and physical exercise recommendations. Anti-diabetic medications included either oral treatment with metformin or glyburide and\or insulin.

RESULTS

Women in the lifestyle modifications group were younger (32.87 vs. 33.79 years, p = 0.012) and had lower pre-pregnancy body-mass-index (25.86 vs. 27.93 kg/m², p < 0.001). Glucose challenge test (GCT) was significantly lower in the lifestyle modifications group (158.31 vs. 171.04 mg/dL in the anti-diabetic treatment group, p < 0.001). Moreover, fasting oral-glucose-tolerance-test (fOGTT) results were significantly lower in the lifestyle modifications group (88.22 vs. 96.34 mg/dL in the anti-diabetic treatment group, p < 0.001). In a receiver-operator-curve analysis, GCT + 4*fOGTT, was the best model to predict lifestyle modifications failure with an area under the curve of 0.7419. Higher rates of vaginal delivery and lower rates of maternal hypoglycemia in the lifestyle modifications group were observed.

CONCLUSIONS

Maternal baseline characteristics and diabetes diagnostic parameters may predict which women will fail to achieve good glycemic control solely by lifestyle modifications.

One-pot synthesis of the organomodified layered double hydroxides - glibenclamide biocompatible nanoparticles

In this work, synthesis of sodium dodecyl sulfate (SDS) organomodified LDH Zn₂Al carrying glibenclamide (GLIB) was performed in one step and in one-pot to obtain nanoparticles (NP). XRD data showed GLIB adsolubilization (d = 14.03 Å) and NP coating with Eudragit L100®. In addition, thermal and XRD data showed exfoliated/intercalated nanocomposite for NP S5 (LDH associated with SDS and Eudragit L100®). LDH organophilization and GLIB intercalation reduced surface area (SBET 23.58 m²/g) and NP size (469 nm). In addition, the change in zeta potential (-35.5 ζ) relative to pristine LDH (SBET 41.34 m²/g, 688.8 nm and +14 ζ) indicated that LDH functionalization seems an appropriate approach to produce NP with greater colloidal stability and enhanced functionality. The zinc release data from the LDH matrix (2.96 % ±0.002 ppm) showed the effectiveness of the coating in acid medium (pH 1.2) and the release data from GLIB showed the kinetics of release of zero order with release in simulated intestinal medium (pH 7.4) of 88 % and 73 % (24 h) for uncoated and coated NP, respectively. All NP were considered biocompatible in the WST-1 assay on BALB 3T3 fibroblast strains making these NP promising therapeutically.

Impact of some oral hypoglycemic agents on type 2 diabetes-associated depression and reserpine-induced depression in rats: the role of brain oxidative stress and inflammation

Diabetes mellitus and depression are comorbid diseases affecting many patients all over the world. The current study was designed to compare the antidepressant effect of some antidiabetic drugs such as vildagliptin, pioglitazone, glyburide, and metformin on depression-related or unrelated to type 2 diabetes mellitus (T2DM). T2DM was induced by high-fat diet and streptozotocin, while diabetes-unrelated depression was induced by reserpine. Antidiabetic agents reduced diabetes-associated depression as indicated by the reduction in the immobility time in the forced swim test, elevation of cortical and hippocampal serotonin and brain-derived neurotrophic factor (BDNF), and the increase in serum β-Amyloid 1-42 (Aβ1-42) levels. Antidiabetic agents also reduced serum corticosterone levels suggesting their inhibitory effect on hypothalamus-pituitary-adrenal axis activity. The antidepressant activity of the tested compounds was associated with reduction of oxidative stress and inflammation in brain. Vildagliptin showed the highest, while glyburide showed the least antidiabetic and antidepressant activity. Antidepressant activities of pioglitazone and metformin were comparable. The difference in antioxidant and anti-inflammatory activities between groups showed the same pattern of the antidepressant effect suggesting that these two pathways may play role in ameliorating depression in diabetic rats. On the other hand, the administration of reserpine in small doses (0.2 mg/kg) induced depression associated with hyperglycemia in non-diabetic rats. Although all treatments improved glycemic parameters to similar levels, vildagliptin showed the greatest effect on Aβ1-42, serotonin, norepinephrine, and BDNF levels. In conclusion, vildagliptin seems to be the leading drug among the tested antidiabetics and may be the most appropriate antidiabetic for managing diabetes-associated depression.

Use of Antidiabetic drugs during pregnancy among U.S. women with Livebirth deliveries in the Mini-Sentinel system

BACKGROUND

As the prevalence of diabetes mellitus increases in the population, the exposure to antidiabetic drugs (ADDs) during pregnancies is expected to grow, as has been seen over the last decade. The objective of this study was to estimate the prevalence of ADD use during pregnancy among women in the Mini-Sentinel Distributed Database (MSDD) who delivered a liveborn infant.

METHODS

We identified qualifying livebirth pregnancies among women aged 10 to 54 years in the MSDD from 2001 to 2013. ADD use was estimated using outpatient pharmacy dispensing claims and days-supplied among three cohorts: all livebirth pregnancies, pregnancies among women with pre-existing diabetes, and pregnancies among women without prior ADD use.

RESULTS

Among the 1.9 million pregnancies in the MSDD that resulted in a livebirth from 2001 to 2013, 4.4% were exposed to an ADD. Of the 15,606 pregnancies (0.8%) with pre-existing diabetes, 92.8% were also exposed during the pregnancy period. The most commonly used product in these pregnancies was insulin (75.6% of pregnancies). In contrast, in pregnancies of women without prior ADD use, the most commonly used products were glyburide and insulin, and most of these users were diagnosed with gestational diabetes.

CONCLUSIONS

Patterns of ADD use during pregnancy described here, along with changes in disease incidence and management, highlight the importance of continuing surveillance of ADD utilization patterns and examining the safety and effectiveness of these products in pregnancy.

Effect of olive leaves extract on the antidiabetic effect of glyburide for possible herb-drug interaction

The concomitant use of olive leaves (OL) and glyburide (GLB) is a possible therapy for diabetic patients. However, there is no report about the effect of OL on the antidiabetic effect of GLB till now. In the current study, the possible interaction of olive leaves extract (OLE) with GLB was assessed to determine if there was any pharmacological benefit over GLB alone. Seven groups of male Sprague Dawley rats were used. Normal rats of the 1st group treated with 2 mL/kg of 3% Tween 80 (vehicle). The 2nd–5th groups were diabetic rats received vehicle, GLB (5 mg/kg), OLE low dose and OLE high dose respectively, while the 6th–7th groups administered combinations of GLB plus OLE low dose and GLB plus OLE high dose, respectively. All treatments were administered orally once daily for 8 weeks.

The use of GLB+OLE-500 obviously improved fasting blood glucose (FBG), insulin and glycated hemoglobin (HbA1c) in diabetic rats (95.5 ± 5.55 mg/dL, 6.8 ± 0.16 mg/dL and 6.1 ± 0.29%, respectively) compared to those treated with GLB monotherapy (140.0 ± 6.36 mg/dL, 5.4 ± 0.19 mg/dL and 7.0 ± 0.20%, respectively). The lipid profile [triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C)] was significantly improved in diabetic rats exposed to GLB+OLE-500 (35.6 ± 1.51 mg/dL, 48.5 ± 2.74 mg/dL, 25.1 ± 1.21 mg/dL and 17.0 ± 0.82 mg/dL, respectively) in comparison with diabetic group exposed to GLB alone (43.2 ± 2.15 mg/dL, 56.8 ± 2.14 mg/dL, 18.6 ± 0.96 mg/dL, 23.0 ± 1.26 mg/dL, respectively). Additionally, the benefit impacts of GLB+OLE-500GLB+OLE-500 therapy on the antioxidant and lipid peroxidation parameters in the pancreatic tissues of diabetic rats were higher than those of GLB monotherapy. Moreover, GLB plus OLE-500 combination had the greatest effect on restoration of the insulin content of Beta (β) cells and reduction of the glucagon and somatostatin of Alpha (α) and Delta (δ) endocrine cells in the pancreatic islets among the different treatment. The current study suggests that OL and GLB combination could cause herb-drug interactions through modulation of insulin receptor (INR), glucose transporter 2 (Slc2a2) and peroxisome proliferator-activated receptor α (PPAR-α) genes expression in the liver of diabetic rats.

SCING-Spinal Cord Injury Neuroprotection with Glyburide: a pilot, open-label, multicentre, prospective evaluation of oral glyburide in patients with acute traumatic spinal cord injury in the USA

INTRODUCTION

Acute traumatic spinal cord injury (tSCI) is a devastating neurological disorder with no pharmacological neuroprotective strategy proven effective to date. Progressive haemorrhagic necrosis (PHN) represents an increasingly well-characterised mechanism of secondary injury after tSCI that negatively impacts neurological outcomes following acute tSCI. Preclinical studies evaluating the use of the Food and Drug Administration-approved sulfonylurea receptor 1-transient receptor potential melastatin 4 channel blocker glyburide in rodent models have shown reduced secondary microhaemorrhage formation and the absence of capillary fragmentation, the pathological hallmark of PHN.

METHODS AND ANALYSIS

In this initial phase multicentre open-label pilot study, we propose to enrol 10 patients with acute cervical tSCI to primarily assess the feasibility, and safety of receiving oral glyburide within 8 hours of injury. Secondary objectives include pharmacokinetics and preliminary evaluations on neurological recovery as well as blood and MRI-based injury biomarkers. Analysis will be performed using the descriptive and non-parametric statistics.

ETHICS AND DISSEMINATION

Glyburide has been shown as an effective neuroprotective agent in preclinical tSCI models and in the treatment of ischaemic stroke with the additional risk of a hypoglycaemic response. Given the ongoing secondary injury and the traumatic hyperglycaemic stress response seen in patients with tSCI, glyburide; thus, offers an appealing neuroprotective strategy to supplement standard of care treatment. The study protocol was approved by the Ohio State University Biomedical Institutional Review Board. The protocol was amended in February 2017 with changes related to study feasibility and patient recruitment. Specifically, the route of administration was changed to the oral form to allow for streamlined and rapid drug administration, and the injury-to-drug time window was extended to 8 hours in an effort to further enhance enrolment. Participants or legally authorised representatives are informed about the trial and its anticipated risks orally and in written form using an approved informed consent form prior to inclusion. The findings of this study will be disseminated to the participants and to academic peers through scientific conferences and peer-reviewed journal publications.

TRIAL REGISTRATION NUMBERS

NCT02524379 and 2014H0335.

Metabolic profile and prolactin serum levels in men with type 2 diabetes mellitus: Old-new rubric

Background:

Prolactin (PRL) is involved in the regulation of glucose metabolism since high PRL serum levels are associated with low incidence of type 2 diabetes mellitus (T2DM). Therefore, the aim of the present study was to assess the metabolic effects of PRL on glucose homeostasis in men with T2DM.

Methods:

Eighty male patients with T2DM compared with 25 male healthy controls matched with patients for age and weight were divided into four groups: Group (A): patients with T2DM on metformin (n = 29), Group (B): patients with T2DM on glyburide (n = 30), Group (C): patients with T2DM on glyburide plus metformin (n = 21), and Group (D): healthy male subjects as control (n = 25). Body mass index (BMI) and blood pressure measurements were determined. Fasting blood glucose (FBG), glycated hemoglobin, total cholesterol, triglyceride (TG), high-density lipoprotein, low-density lipoprotein, atherogenic index, fasting serum insulin, insulin resistance (IR), and β-cell function of the pancreas were determined by homeostatic model assessment-2 (HOMA-IR). Furthermore, C-reactive protein and PRL serum level were determined in patients with T2DM and healthy control men.

Results:

BMI of T2DM patients was higher as compared with control (P = 0.003). Combination therapy (glyburide plus metformin) in patients with T2DM showed better effect on most of glycemic indices and lipid profile than glyburide or metformin monotherapy (P < 0.05). PRL serum level was higher in patients with T2DM as compared with control (P = 0.001). PRL serum level was high in glyburide-treated patients as compared with metformin-treated patients (P = 0.002).

Conclusion:

This study concludes that elevated PRL serum level in patients with T2DM is associated with diabetic complications. Diabetic pharmacotherapy mainly metformin reduced PRL serum level in patients with T2DM through amelioration of IR.

NLRP3 inflammasome inhibitor glyburide expedites diabetic-induced impaired fracture healing

Localized inflammation is accompanied by the diabetic-induced fracture. The present study aims to investigate the therapeutic effects of glyburide, an NLRP3 inflammasome inhibitor, in a diabetic-induced fracture model. An animal model of diabetic-induced fracture was established and the mice were administrated with metformin or glyburide for 3 weeks. Quantitative polymerase chain reaction (qPCR) and Western blotting were used to evaluate the relative expressions of IFN-γ, TNF-α, and IL-6. Micro-computed tomography (μCT) scanning was applied to evaluate bone callus formation. Histopathology examinations of fractured femur sections were performed using Tartrate-resistant acid phosphatase (TRAP) staining and Alcian blue and orange G staining. Bone strength was evaluated using Torsional testing. Our results showed that treatment of glyburide significantly decreased the expressions of IFN-γ, TNF-α, and IL-6 in the fracture calluses in diabetic-induced fracture model, while bone callus volume and bone volume fraction were increased. Additionally, our results also demonstrated that treatment of glyburide rescued the increase of osteoclasts in the bone-cartilage interface. Apart from decreasing a percentage of cartilage area and increasing the percentage of bone and fibrotic tissue area, treatment of glyburide increased the maximum torque and yield torque of fractures. These results implied that glyburide might be used as a potential drug candidate for diabetic-induced fracture.

Precision Medicine: Long-Term Treatment with Sulfonylureas in Patients with Neonatal Diabetes Due to KCNJ11 Mutations

PURPOSE OF REVIEW

The goal of this review is to provide updates on the safety and efficacy of long-term sulfonylurea use in patients with KCNJ11-related diabetes. Publications from 2004 to the present were reviewed with an emphasis on literature since 2014.

RECENT FINDINGS

Sulfonylureas, often taken at high doses, have now been utilized effectively in KCNJ11 patients for over 10 years. Mild-moderate hypoglycemia can occur, but in two studies with a combined 975 patient-years on sulfonylureas, no severe hypoglycemic events were reported. Improvements in neurodevelopment and motor function after transition to sulfonylureas continue to be described. Sulfonylureas continue to be an effective, sustainable, and safe treatment for KCNJ11-related diabetes. Ongoing follow-up of patients in research registries will allow for deeper understanding of the facilitators and barriers to long-term sustainability. Further understanding of the effect of sulfonylurea on long-term neurodevelopmental outcomes, and the potential for adjunctive therapies, is needed.

Analgesic effects of eucalyptus essential oil in mice

Background

The use of aroma oils dates back to at least 3000 B.C., where it was applied to mummify corpses and treat the wounds of soldiers. Since the 1920s, the term “aromatherapy” has been used for fragrance therapy with essential oils. The purpose of this study was to determine whether the essential oil of Eucalyptus (EOE) affects pain pathways in various pain conditions and motor coordination.

Methods

Mice were subjected to inhalation or intraperitoneal injection of EOE, and its analgesic effects were assessed by conducting formalin, thermal plantar, and acetic acid tests; the effects of EOE on motor coordination were evaluated using a rotarod test. To determine the analgesic mechanism, 5′-guanidinonaltrindole (κ-opioid antagonist, 0.3 mg/kg), naltrindole (δ-opioid antagonist, 5 mg/kg), glibenclamide (δ-opioid antagonist, 2 mg/kg), and naloxone (μ-opioid antagonist, 4, 8, 12 mg/kg) were injected intraperitoneally.

Results

EOE showed an analgesic effect against visceral pain caused by acetic acid (EOE, 45 mg/kg); however, no analgesic effect was observed against thermal nociceptive pain. Moreover, it was demonstrated that EOE did not have an effect on motor coordination. In addition, an anti-inflammatory effect was observed during the formalin test.

Conclusions

EOE, which is associated with the μ-opioid pain pathway, showed potential effects against somatic, inflammatory, and visceral pain and could be a potential therapeutic agent for pain.

Pharmacotherapy for hyperglycemia in pregnancy - Do oral agents have a place?

Diabetes is a frequent condition in pregnancy and achieving adequate glycemic control is of paramount importance. Insulin treatment is the gold standard, oral agents are more attractive, but their safety and efficiency should be a prerequisite for their use. We have more information regarding treatment of women with gestational diabetes mellitus where glyburide can induce a picture of fetal hyperinsulinism (higher birthweight and more neonatal hypoglycemia) whereas metformin requires supplemental insulin in a larger proportion of women but achieves satisfactory perinatal outcomes with the exception of preterm birth. Information in patients with Type 2 Diabetes Mellitus is much more limited but also favors metformin. Combinations provide additional possibilities. However, as to long-term outcomes, we have no information on the impact of exposure to glyburide and it is still unclear if in utero exposure to metformin will have any effect on the offspring and the direction of this effect. Women prefer oral agents, indicating the need of additional studies.

Oral Agents for the Treatment of Gestational Diabetes

PURPOSE OF REVIEW

To review the current evidence of the safety and efficacy of the use of oral agents for treatment of gestational diabetes (GDM).

RECENT FINDINGS

The use of metformin and glyburide in pregnancy for treatment of GDM has dramatically increased since the early 2000s. Meta-analyses suggest that glyburide may increase the risk for large for gestational (LGA) infants and neonatal hypoglycemia. Conversely, metformin may potentially decrease rates of pregnancy-induced hypertension, LGA, neonatal hypoglycemia, and maternal weight gain. However, recent long-term offspring studies indicate a potential detrimental effect of metformin on fat mass that suggests an effect of such medication on fetal programming. While there have been several novel oral anti-diabetes medications brought to market in the past decade, there is minimal data to guide use and in particular data regarding long-term safety for the exposed offspring of treated women. Most professional societies recommend insulin as first-line treatment of gestational diabetes after failure of lifestyle modification. Both metformin and glyburide cross the placenta and long-term safety data is limited. However, patient satisfaction is substantially higher with use of oral agents, and the current literatures suggest that metformin may reduce several common short-term adverse outcomes related to GDM.

Gestational diabetes mellitus: Multi-disciplinary treatment approaches

Gestational diabetes mellitus (GDM) is the most common metabolic disease of pregnancy, associated with several perinatal complications. Adequate glycemic control has been proved to decrease risk of GDM-related complications. Several studies have shown the beneficial effect of exercise and medical nutrition treatment on glycemic and weight control in GDM-affected women. Moreover, pharmacological agents, such as insulin and specific oral anti-diabetic agents can be prescribed safely during pregnancy, decreasing maternal blood glucose and, thus, perinatal adverse outcomes. Multi-disciplinary treatment approaches that include both lifestyle modifications (medical nutritional therapy and daily physical exercise) and pharmacological treatment, in cases of failure of the former, constitute the most effective approach. Insulin is the gold standard pharmacological agent for GDM treatment. Metformin and glyburide are two oral anti-diabetic agents that could serve as alternative, although not equal in terms of effectiveness and safety, treatment for GDM. As studies on short-term safety of metformin are reassuring, in some countries it is considered as first-line treatment for GDM management. More studies are needed to investigate the long-term effects on offspring. As safety issues have been raised on the use of glyburide during pregnancy, it must be used only when benefits surpass possible risks.

Neonatal Diabetes Mellitus: An Update on Diagnosis and Management

Neonatal diabetes mellitus is likely to be due to an underlying monogenic defect when it occurs at less than 6 months of age. Early recognition and urgent genetic testing are important for predicting the clinical course and raising awareness of possible additional features. Early treatment of sulfonylurea-responsive types of neonatal diabetes may improve neurologic outcomes. It is important to distinguish neonatal diabetes mellitus from other causes of hyperglycemia in newborns. Other causes include infection, stress, inadequate pancreatic insulin production in preterm infants, among others. This review explores the diagnostic approach, mutation types, management, and clinical course of neonatal diabetes.

Factitious Hypoglycemia Caused by a Unique Pattern of Drug Use: A Case Report

INTRODUCTION

Factitious hypoglycemia, caused by the surreptitious use of insulin and sulfonylureas, is one of the most challenging differential diagnoses of hypoglycemia. Diagnosis is usually established via exclusion with respect to the special patterns of plasma insulin and C-peptide during hypoglycemic episodes.

CASE PRESENTATION

We report a case of recurrent hypoglycemic episodes and confusing patterns of insulin and C-peptide levels. In the primary evaluations, insulinoma was suspected considering the high plasma concentrations of insulin and C-peptide, besides negative urine and plasma sulfonylureas during hypoglycemic episodes. Considering the normal imaging studies and refractory hypoglycemia to medical therapy, distal pancreatectomy was performed. The patient had no episodes of hypoglycemia after the surgery. Five months later, similar episodes recurred. Further investigations revealed different plasma concentrations of insulin and C-peptide in each hypoglycemic episode. Regarding various biochemical patterns during hypoglycemia and absence of evidence supporting other differential diagnoses, we suspected factitious causes. Close observation revealed that the patient had a history of intermittent glyburide consumption and analog insulin injection.

DISCUSSION

Most commercial insulin immunoassays can only detect human insulin and lack the ability to identify synthetic analog insulin. In addition, common detection methods for sulfonylureas and meglitinides are of low diagnostic value in the human plasma and urine. These laboratory defects can lead to the misdiagnosis of insulinoma or noninsulin-mediated hypoglycemia due to the surreptitious use of insulin secretagogues or analog insulin, respectively. Therefore, due to the lack of any definitive laboratory findings, clinical suspicion is the best strategy for diagnosis.

Antidiabetic drug glyburide modulates depressive-like behavior comorbid with insulin resistance

Background

Abundant reports indicated that depression was often comorbid with type 2 diabetes and even metabolic syndrome. Considering they might share common biological origins, it was tentatively attributed to the chronic cytokine-mediated inflammatory response which was induced by dysregulation of HPA axis and overactivation of innate immunity. However, the exact mechanisms remain obscure. Herein, we mainly focused on the function of the NLRP3 inflammasome to investigate this issue.

Methods

Male C57BL/6 mice were subjected to 12 weeks of chronic unpredictable mild stress (CUMS), some of which were injected with glyburide or fluoxetine. After CUMS procedure, behavioral and metabolic tests were carried out. In order to evaluate the systemic inflammation associated with inflammasome activation, IL-1β and inflammasome components in hippocampi and pancreases, as well as corticosterone and IL-1β in serum were detected separately. Moreover, immunostaining was performed to assess morphologic characteristics of pancreases.

Results

In the present study, we found that 12 weeks’ chronic stress resulted in depressive-like behavior comorbid with insulin resistance. Furthermore, antidiabetic drug glyburide, an inhibitor of the NLRP3 inflammasome, was discovered to be effective in preventing the experimental comorbidity. In brief, it improved behavioral performance, ameliorated insulin intolerance as well as insulin signaling in the hippocampus possibly through inhibiting NLRP3 inflammasome activation by suppressing the expression of TXNIP.

Conclusions

All these evidence supported our hypothesis that chronic stress led to comorbidity of depressive-like behavior and insulin resistance via long-term mild inflammation. More importantly, based on the beneficial effects of blocking the activation of the NLRP3 inflammasome, we provided a potential therapeutic target for clinical comorbidity and a new strategy for management of both diabetes and depression.

Glyburide treatment in gestational diabetes is associated with increased placental glucose transporter 1 expression and higher birth weight

Use of glyburide in gestational diabetes (GDM) has raised concerns about fetal and neonatal side effects, including increased birth weight. Placental nutrient transport is a key determinant of fetal growth, however the effect of glyburide on placental nutrient transporters is largely unknown. We hypothesized that glyburide treatment in GDM pregnancies is associated with increased expression of nutrient transporters in the syncytiotrophoblast plasma membranes. We collected placentas from GDM pregnancies who delivered at term and were treated with either diet modification (n = 15) or glyburide (n = 8). Syncytiotrophoblast microvillous (MVM) and basal (BM) plasma membranes were isolated and expression of glucose (glucose transporter 1; GLUT1), amino acid (sodium-coupled neutral amino acid transporter 2; SNAT2 and L-type amino acid transporter 1; LAT1) and fatty acid (fatty acid translocase; FAT/CD36, fatty acid transporter 2 and 4; FATP2, FATP4) transporters was determined by Western blot. Additionally, we determined GLUT1 expression by confocal microscopy in cultured primary human trophoblasts (PHT) after exposure to glyburide. Birth weight was higher in the glyburide-treated group as compared to diet-treated GDM women (3764 ± 126 g vs. 3386 ± 75 g; p < 0.05). GLUT1 expression was increased in both MVM (+50%; p < 0.01) and BM (+75%; p < 0.01). In contrast, MVM FAT/CD36 (-65%; p = 0.01) and FATP2 (-65%; p = 0.02) protein expression was reduced in mothers treated with glyburide. Glyburide increased membrane expression of GLUT1 in a dose-dependent manner in cultured PHT. This data is the first to show that glyburide increases GLUT1 expression in syncytiotrophoblast MVM and BM in GDM pregnancies, and may promote transplacental glucose delivery contributing to fetal overgrowth.

[Glyburide prevents pulmonary artery smooth muscle cell proliferation and migration via inhibiting NLRP3 activation]

Objective: To investigate whether glyburide prevents platelet-derived growth factor (PDGF) induced pulmonary artery smooth muscle cells(PASMCs) proliferation and migration via inhibiting nucleotide binding domain leucine-rich repeat-containing receptors protein 3(NLRP3) inflammasome activation. Methods: PASMCs were divided into 4 groups: control group, glyburide group, PDGF group and PDGF+ glyburide group. Cell proliferation and migration were assessed by MTT and Transwell respectively. The NLRP3 inflammasome activation was assessed by Western blot. Results: Compared with the control group, the protein expressions of NLRP3, caspase-1 and IL-1β in PASMCs were increased to (1.38±0.09, t=3.998, P<0.001), (1.32±0.1, t=3.268, P<0.01)and(1.43±0.19) (t=2.096, P<0.05) folds in the PDGF group. Glyburide had no effect on NLRP3, caspase-1 and IL-1β expression as compared with the control group, while the NLRP3, caspase-1 and IL-1β were decreased by(20.49±7.6)% (t=2.862, P<0.01), (32.94±3.44)% (t=4.154, P<0.001) and (24.67±5.29)% (t=2.335, P<0.05) in the PDGF+ glyburide group, respectively, as compared with the PDGF group. Compared with the control group, the PASMCs proliferation and migration in the PDGF group were significantly increased to (1.74±0.23, t=4.717, P<0.001) and (3.12±0.8, t=5.249, P<0.001) folds, respectively. Compared with the control group, glyburide had no effect on PASMCs proliferation and migration. In PDGF+ glyburide group, cell proliferation was reduced by (50.5±4.27)% (t=4.462, P<0.001) and cell migration count was lower than in the PDGF group (42.77±2.84)% (t=3.716, P<0.001). Conclusion: Glyburide could ameliorate PDGF-induced PASMCs proliferation and migration by inhibiting NLRP3 inflammasome activation.

The role of particle size of glyburide crystals in improving its oral absorption

Currently, nanosizing is becoming increasingly prevalent as an efficient way for the improvement of oral drug absorption. This study mainly focuses on two points, namely the crystal properties, and the in vitro and in vivo characterizations of drug crystals during the nanosizing process. We used glyburide, an oral type 2 diabetes (T2D) medication, as our model drug. We sought to reduce the crystalline size of this drug and evaluate its absorption properties by comparing it with the original coarse drug because of previous reports about its gastrointestinal absorption insufficiency. Glyburide crystals, ranging from 237.6 to 4473 nm were prepared successfully by jet milling and media milling. The particle sizes and the crystal morphology were analyzed by characterization of the solid states, equilibrium solubility, and dissolution behavior. Additionally, pharmacokinetic study was performed in SD rats. The solid state results indicated a loss in crystallinity, amide-imidic acid interconversion, and partial amorphization during nanosizing. Further, in in vitro tests, nanocrystal formulations remarkably increased the solubility and dissolution of the drug (compared to microcrystals). In the in vivo test, reducing the particle size from 601.3 to 312.5 nm showed no improvement on the C _max and AUC _(0-36 h) values, while a profound slowing of the drug elimination occurred with reduction of particle size. Further reduction from 312.5 to 237.6 nm lead to a significant increase (p < 0.001) of the AUC _(0-36 h) from 6857.8 ± 369.3 ng mL^-1 h to 12,928.3 ± 1591.4 ng mL^-1 h, respectively, in rats. Our present study confirmed that nanosizing has a tremendous impact on promoting the oral absorption of glyburide.

[Effects of different sulfonylureas on the warm-up phenomenon in diabetes patients with coronary artery disease]

Objective: To explore the different effects of chronic treatment with glibenclamide and gliclazide on the warm-up phenomenon in diabetes patients with coronary artery disease. Methods: A total of seventy-one patients with chronic stable angina and diabetes who were positive for exercise test and was proven that the stenosis degree was 70%-90% in at least one major branch through coronary angiogram were included into the study.They were divided into three groups, diet control group (DMD), glibenclamide group (DMG1) and gliclazide group (DMG2), according to the treatment of diabetes.All of the patients underwent two bicycle exercise tests (EX) at 15-minute interval.Parameters including ischaemic threshold (the rate-pressure product at 1-mm ST-segment depression, RPP), time to ischaemic (the time to 1 mm ST-segment depression, T-STD), the maximum ST-segment depression (STDmax) and exercise duration (ED) were recorded respectively. Results: In group DMD, T-STD and ED were prolonged [(360±83) s vs (409±80) s, P<0.001] and [(518±90) s vs (549±96) s, P=0.001], STDmax were shortened [(1.91±0.43) mm vs (1.60±0.36) mm, P<0.001], and RPP was increased [(180±27) beats·min(-1)·mmHg·10(2) vs (195±28) beats·min(-1)·mmHg·10(2), P<0.001] as the parameters during EX2 were compared with those during EX1. In group DMG1, there was no statistic difference in these indexes except that ED was prolonged [(458±70) s vs (472±66) s, P=0.045] when those of EX2 and EX1were compared. In the group DMG2, all the analyzed variables improved significantly during two sequential exercise tests as the results in the group DMD except that ischaemic threshold was not increased [(199±41) beats·min(-1)·mmHg·10(2) vs (211±39) beats·min(-1)·mmHg·10(2), P=0.071]. Conclutions: Warm-up phenomenon is abolished in diabetic patients with stable angina treated with glibenclamide, partially preserved in gliclazide-treated patients. and the KATP channel may be involved in those different effects. Gliclazide should be the safer choice for the patients with diabetes and chronic stable angina.

Pharmacological Management of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is one of the most common morbidities complicating pregnancy, with short- and long-term consequences to the mothers, fetuses, and newborns. Management and treatment are aimed to achieve best possible glycemic control, while avoiding hypoglycemia and ensuring maternal and fetal safety. It involves behavioral modifications, nutrition and medications, if needed; concurrent with maternal and fetal surveillance for possible adverse outcomes. This review aims to elaborate on the pharmacological options for GDM therapy. We performed an extensive literature review of different available studies, published during the last 50 years, concerning pharmacological therapy for GDM, dealing with safety and efficacy, for both fetal and maternal morbidity consequences; as well as failure and success in establishing appropriate metabolic and glucose control. Oral medication therapy is a safe and effective treatment modality for GDM and in some circumstances may serve as first-line therapy when nutritional modifications fail. When oral agents fail to establish glucose control then insulin injections should be added. Determining the best oral therapy in inconclusive, although it seems that metformin is slightly superior to glyburide, in some aspects. As for parenteral therapy, all insulins listed in this article are considered both safe and effective for treatment of hyperglycemia during pregnancy. Importantly, a better safety profile, with similar efficacy is documented for most analogues. As GDM prevalence rises, there is a need for successful monitoring and treatment for patients. Caregivers should know the possible and available therapeutic options.

Pregnancy snapshot: a retrospective, observational case-control study to evaluate the potential effects of maternal diabetes treatment during pregnancy on macrosomia

OBJECTIVE

Pregnancy in women with diabetes is associated with increased incidence of macrosomia (high birth weight) versus women without diabetes. Macrosomia increases the risk of complications during delivery and neonatally. The potential effect on macrosomia incidence certain diabetes treatments may have is not fully established. This study aims to identify whether specific components of the prenatal care of mothers with diabetes are associated with increased macrosomia risk in a real-world U.S.

RESEARCH DESIGN AND METHODS

Retrospective, observational case-controlled study of mothers either without diabetes, or with type 1 (T1D), type 2 (T2D), or gestational diabetes mellitus (G.D.M.), using data from a U.S. insurance claims database. Treatment selection was at physician discretion.

MAIN OUTCOME MEASURE

Incidence of macrosomia.

RESULTS

For mothers with T2D, use of neutral protamine Hagedorn (N.P.H.) insulin and glyburide increased during pregnancy, from 3.4% to 33.3%, and 3.7% to 16.5%, respectively. The most common G.D.M. treatments during pregnancy were glyburide (15.5%), N.P.H. (12.9%), basal-bolus therapy (10.0%), and metformin (8.1%). Endocrinologist care during pregnancy was associated with insulin use - but not glyburide use - for mothers with G.D.M., and with insulin use for mothers with T1D and T2D (compared with mothers not visiting an endocrinologist). Glyburide was associated with higher odds for macrosomia: G.D.M. (odds ratio [O.R.] 1.53, 95% confidence interval [C.I.] 1.38-1.69, p < 0.0001); T2D (O.R. 1.93, 95% C.I. 1.51-2.47, p < 0.0001). Endocrinologist care was associated with lower odds for macrosomia overall (O.R. 0.86, 95% C.I. 0.81-0.92) and for mothers with G.D.M. (O.R. 0.85, 95% C.I. 0.75-0.97, p = 0.0156) when the sub-populations were examined in separate models.

CONCLUSIONS

Healthcare utilization and endocrinologist care were related to positive birth outcomes, especially with G.D.M. Further research into the safety and efficacy of glyburide in pregnancy is warranted. This study cannot infer causality and may not be representative of current U.S. healthcare practice.

Novel Treatments in Neuroprotection for Aneurysmal Subarachnoid Hemorrhage

OPINION STATEMENT

New neuroprotective treatments aimed at preventing or minimizing "delayed brain injury" are attractive areas of investigation and hold the potential to have substantial beneficial effects on aneurysmal subarachnoid hemorrhage (aSAH) survivors. The underlying mechanisms for this "delayed brain injury" are multi-factorial and not fully understood. The most ideal treatment strategies would have the potential for a pleotropic effect positively modulating multiple implicated pathophysiological mechanisms at once. My personal management (RFJ) of patients with aneurysmal subarachnoid hemorrhage closely follows those treatment recommendations contained in modern published guidelines. However, over the last 5 years, I have also utilized a novel treatment strategy, originally developed at the University of Maryland, which consists of a 14-day continuous low-dose intravenous heparin infusion (LDIVH) beginning 12 h after securing the ruptured aneurysm. In addition to its well-known anti-coagulant properties, unfractionated heparin has potent anti-inflammatory effects and through multiple mechanisms may favorably modulate the neurotoxic and neuroinflammatory processes prominent in aneurysmal subarachnoid hemorrhage. In my personal series of patients treated with LDIVH, I have found significant preservation of neurocognitive function as measured by the Montreal Cognitive Assessment (MoCA) compared to a control cohort of my patients treated without LDIVH (RFJ unpublished data presented at the 2015 AHA/ASA International Stroke Conference symposium on neuroinflammation in aSAH and in abstract format at the 2015 AANS/CNS Joint Cerebrovascular Section Annual Meeting). It is important for academic physicians involved in the management of these complex patients to continue to explore new treatment options that may be protective against the potentially devastating "delayed brain injury" following cerebral aneurysm rupture. Several of the treatment options included in this review show promise and could be carefully adopted as the level of evidence for each improves. Other proposed neuroprotective treatments like statins and magnesium sulfate were previously thought to be very promising and to varying degrees were adopted at numerous institutions based on somewhat limited human evidence. Recent clinical trials and meta-analysis have shown no benefit for these treatments, and I currently no longer utilize either treatment as prophylaxis in my practice.

Oral hypoglycemic agents: do the ends justify the means?

BACKGROUND

Glyburide has replaced insulin as the first line of therapy in the treatment of gestational diabetes in the United States. Glyburide and metformin therapies were reported to be comparable to insulin yet also cost-effective, patient-friendly, and potentially compliance-enhancing. Recently, the efficacy of the use of these oral hypoglycemic drugs has been questioned. In this review, the questionable concerns will be addressed: Which diabetic drug(s) cross the placenta? What is the quality of evidence and the data source validity? Which treatment modalities are most effective in reducing the primary outcome in GDM? Which drug is most effective in improving secondary outcomes?

FINDINGS

This review documents the methodological issues in study design that have impacted the results for the provision of health care interventions in GDM. The review summarizes the contents of the articles qualitatively and assesses the theoretical and empirical evidence. Multiple types of studies exist and every study design serves a specific purpose. Different study designs addressing the same question can yield varying results. The risk of presenting uncertain results without categorically knowing the direction and magnitude of the effect holds true for both randomized and nonrandomized controlled trials. The review further emphasizes the importance of achieving the targeted levels of glycemic control.

CONCLUSION

The implications of this review are critical to addressing the current gaps in the literature on the efficacy of the use of oral hypoglycemic agents in GDM. The emphasis needs to be placed on patient treatment in order to manage hyperglycemia to reduce fetal and maternal morbidity. In this regard, we need to delineate proper outcome criteria that will reflect disease severity and treat using appropriate pharmacological therapy.

Counterregulatory responses to hypoglycemia differ between glimepiride and glyburide in non diabetic individuals

OBJECTIVE

Reported rates of hypoglycemia in patients with type 2 diabetes mellitus are lower with glimepiride as compared to glyburide. The aim of this study was to determine whether physiologic differences in counterregulatory neuroendocrine and metabolic mechanisms during hypoglycemia provide a basis for the observed clinical differences between glimepiride and glyburide.

RESEARCH DESIGN AND METHODS

Non-diabetic volunteers (age 38±2years, BMI 26±1kg/m(2)) were studied in a single-blind fashion during separate 2day randomized protocols consisting of 2h hyperinsulinemic (9pmol/kg/min) euglycemic (4.9±0.1mmol) and hypoglycemic (2.9±0.1mmol/L) clamps. Individuals received biologically equivalent doses of glimepiride (4mg) or glyburide (10mg) 1h prior to each glucose clamp (n=11) as well as a control group of placebo studies. Glucose kinetics were calculated using D-Glucose-6-6d2.

RESULTS

Insulin and C-peptide levels were increased (p<0.05) during euglycemia in both sulfonylurea groups as compared to placebo. However, despite equivalent hypoglycemia, insulin and C-peptide levels were higher (p<0.05) only after glyburide. Glucagon responses and endogenous glucose production (EGP) were decreased (p<0.05) during hypoglycemia following glyburide administration as compared to glimepiride. Glyburide reduced (p<0.05) norepinephrine responses during euglycemic clamps. In addition combined epinephrine and norepinephrine responses during hypoglycemia were reduced (p<0.05) following glyburide as compared to placebo. Leptin levels fell by a greater amount (p<0.05) during hypoglycemia with both sulfonylureas as compared to placebo.

CONCLUSIONS

In summary, glimepiride and glyburide can both similarly increase insulin and C-peptide levels during hyperinsulinemic euglycemia. However, during moderate hyperinsulinemic hypoglycemia (2.9mmol/L) glyburide resulted in increased C-peptide and insulin, but blunted glucagon, sympathetic nervous system and EGP responses. We conclude that glyburide can acutely reduce key neuroendocrine and metabolic counterregulatory defenses during hypoglycemia in healthy individuals.

Paroxetine decreased plasma exposure of glyburide partly via inhibiting intestinal absorption in rats

Accumulating evidences have shown that diabetes is often accompanied with depression, thus it is possible that oral antidiabetic agent glyburide and antidepressive agent paroxetine are co-administered in diabetic patients. The aim of this study was to assess interactions between glyburide and paroxetine in rats. Effect of paroxetine on pharmacokinetics of orally administered glyburide was investigated. Effect of naringin (NAR), an inhibitor of rat intestinal organic anion transporting polypeptides 1a5 (Oatp1a5), on pharmacokinetics of glyburide was also studied. The results showed that co-administration of paroxetine markedly reduced plasma exposure and prolonged Tmax of glyburide, accompanied by significant increase in fecal excretion of glyburide. Co-administration of naringin also significantly decreased plasma exposure of glyburide. Data from intestinal perfusion experiments showed that both paroxetine and naringin significantly inhibited intestinal absorption of glyburide. Caco-2 cells were used to investigate whether paroxetine and naringin affected intestinal transport of glyburide and fexofenadine (a substrate of Oatp1a5). The results showed that both paroxetine and naringin greatly inhibited absorption of glyburide and fexofenadine. All results gave a conclusion that co-administration of paroxetine decreased plasma exposure of glyburide in rats via inhibiting intestinal absorption of glyburide, which may partly be attributed to the inhibition of intestinal Oatp1a5 activity.

Use of oral anti-diabetic agents in pregnancy: a pragmatic approach

Insulin is the gold standard for treatment of hyperglycemia during pregnancy, when lifestyle measures do not maintain glycemic control during pregnancy. However, recent studies have suggested that certain oral hypoglycemic agents (metformin and glyburide) may be safe and be acceptable alternatives. There are no serious safety concerns with metformin, despite it crossing the placenta. Neonatal outcomes are also comparable, with benefit of reductions in neonatal hypoglycemia, maternal hypoglycemia and weight gain, and improved treatment satisfaction. Glibenclamide is more effective in lowering blood glucose in women with gestational diabetes, and with a lower treatment failure rate than metformin. Although generally well-tolerated, some studies have reported higher rates of pre-eclampsia, neonatal jaundice, longer stay in the neonatal care unit, macrosomia, and neonatal hypoglycaemia. There is also paucity of long-term follow-up data on children exposed to oral agents in utero. This review aims to provide an evidence-based approach, concordant with basic and clinical pharmacological knowledge, which will help medical practitioners use oral anti-diabetic agents in a rational and pragmatic manner. Pubmed search was made using Medical Subject Headings (MESH) terms “Diabetes” and “Pregnancy” and “Glyburide”; “Diabetes” and “Pregnancy” and “Metformin”. Limits were randomized controlled trials (RCTs) and meta-analysis. The expert reviews on the topic were also used for discussion. Additional information (studies/review) pertaining to discussion under sub-headings like safety during breastfeeding; placental transport; long-term safety data were searched (pubmed/cross-references/expert reviews).

Gestational diabetes mellitus management with oral hypoglycemic agents

Oral hypoglycemic agents such as glyburide (second-generation sulfonylurea) and metformin (biguanide) are attractive alternatives to insulin due to lower cost, ease of administration, and better patient adherence. The majority of evidence from retrospective and prospective studies suggests comparable efficacy and safety of oral hypoglycemic agents such as glyburide and metformin as compared to insulin when used in the treatment of women with gestational diabetes mellitus (GDM). Glyburide and metformin have altered pharmacokinetics during pregnancy and both agents cross the placenta. In this article, we review the efficacy, safety, and dosage of oral hypoglycemic agents for the treatment of gestational diabetes mellitus. Additional research is needed to evaluate optimal dosage for glyburide and metformin during pregnancy. Comparative studies evaluating the effects of glyburide and metformin on long-term maternal and fetal outcomes are also needed.

Identification of CYP3A7 for glyburide metabolism in human fetal livers

Glyburide is commonly prescribed for the treatment of gestational diabetes mellitus; however, fetal exposure to glyburide is not well understood and may have short- and long-term consequences for the health of the child. Glyburide can cross the placenta; fetal concentrations at term are nearly comparable to maternal levels. Whether or not glyburide is metabolized in the fetus and by what mechanisms has yet to be determined. In this study, we determined the kinetic parameters for glyburide depletion by CYP3A isoenzymes; characterized glyburide metabolism by human fetal liver tissues collected during the first or early second trimester of pregnancy; and identified the major enzyme responsible for glyburide metabolism in human fetal livers. CYP3A4 had the highest metabolic capacity towards glyburide, followed by CYP3A7 and CYP3A5 (Clint,u=37.1, 13.0, and 8.7ml/min/nmol P450, respectively). M5 was the predominant metabolite generated by CYP3A7 and human fetal liver microsomes (HFLMs) with approximately 96% relative abundance. M5 was also the dominant metabolite generated by CYP3A4, CYP3A5, and adult liver microsomes; however, M1-M4 were also present, with up to 15% relative abundance. CYP3A7 protein levels in HFLMs were highly correlated with glyburide Clint, 16α-OH DHEA formation, and 4'-OH midazolam formation. Likewise, glyburide Clint was highly correlated with 16α-OH DHEA formation. Fetal demographics as well as CYP3A5 and CYP3A7 genotype did not alter CYP3A7 protein levels or glyburide Clint. These results indicate that human fetal livers metabolize glyburide predominantly to M5 and that CYP3A7 is the major enzyme responsible for glyburide metabolism in human fetal livers.

In vitro biological evaluation of glyburide as potential inhibitor of collagenases

In tissues with upregulated MMP activity, MMP inhibition remains one of the key strategies. Potential inhibitors of MMPs have been tested for almost 30 years, but none have reached clinical utility due to bioavailability issues and adverse effects. This study utilized the approach of drug repurposing for exploring glyburide as a potential inhibitor against collagenases. In silico molecular docking studies were carried out to probe the interactions of glyburide with the active site Zn. Collagenase enzyme activity measurements and zymography analyses using conditioned medium from lung fibroblasts, rheumatoid synovial fibroblasts, and osteoblasts were carried out to confirm the inhibitory activity. Glyburide binds and interacts with the catalytic Zn residues of the collagenases, as evidenced by in silico molecular docking studies. Fluorescence enzyme activity measurements reveal that glyburide inhibits peptide substrate cleavage by all three collagenases in a dose-dependent manner. Collagen zymography studies validated inhibition of these collagenases by glyburide. These results identify glyburide as a potential inhibitor of collagenases and provide an insight into the mechanism of action of this small molecule. Thus, glyburide may offer additional advantages in diabetics, in controlling MMP activation and collagen degradation and could aid in the treatment of diseases with aberrant MMP activity.

The use of glyburide in the management of gestational diabetes mellitus: a meta-analysis

PURPOSE

Glyburide has been used for managing gestational diabetes mellitus (GDM) in a number of countries. It is rather inexpensive. However, its efficacy and safety remain controversial. With this meta-analysis, we evaluated glyburide in comparison with insulin.

MATERIAL/METHODS

With a systematic literature search strategy, a total of 93 randomized controlled trials (RCTs) with insulin and glyburide comparison were identified. Based on the revised Consolidated Standards of Reporting Trials (CONSORT) checklist, five of them met the inclusion criteria and were included in this meta-analysis.

RESULTS

Six hundred and seventy four subjects were included in these five RCTs. When compared with insulin, glyburide had an increased relative risk (RR) for neonatal hypoglycemia (RR: 1.98; 95% confidence interval [CI]: 1.17, 3.36). Estimation of standard mean differences (SMD) showed that both fetal birth weight and incidence of macrosomia were higher in subjects receiving glyburide than in those receiving insulin (SMD: 0.21; 95% CI: 0.06, 0.36; RR: 2.22; 95% CI: 1.07, 4.61 respectively). There were no significant differences in maternal glucose control, glycated hemoglobin, the rate of Cesarean section, large-for-gestational age, neonatal hypocalcemia, length of stay for neonatal ICU admissions, preterm birth, or congenital anomalies.

CONCLUSIONS

Our study suggested that in women with GDM, glyburide is as effective as insulin, but the risks of neonatal hypoglycemia, high fetal birth weight, and macrosomia were higher.

Antidiabetic-drug combination treatment for glucose intolerance in adult female rats treated acutely with olanzapine

Second generation antipsychotic drugs are routinely used as treatment for psychotic disorders. Many of these compounds, including olanzapine, cause metabolic side-effects such as impaired glucose tolerance and insulin resistance. Individual antidiabetic drugs can help control elevated glucose levels in patients treated with antipsychotics, but the effects of combining antidiabetics, which routinely occurs with Type 2 diabetes mellitus patients, have never been studied. Presently, we compared the effects of the three different antidiabetics metformin (500mg/kg, p.o.), rosiglitazone (30mg/kg, p.o.) and glyburide (10mg/kg, p.o.) on metabolic dysregulation in adult female rats treated acutely with olanzapine. In addition, dual combinations of each of these antidiabetics were compared head-to-head against each other and the individual drugs. The animals received two daily treatments with antidiabetics and were then treated acutely with olanzapine (10mg/kg, i.p.). Fasting glucose and insulin levels were measured, followed by a 2h glucose tolerance test. Olanzapine caused a large and highly significant glucose intolerance compared to vehicle treated rats. Rosiglitazone decreased glucose levels non-significantly, while both metformin and glyburide significantly decreased glucose levels compared to olanzapine-only treated animals. For antidiabetic dual-drug combinations, the rosiglitazone-metformin group showed an unexpected increase in glucose levels compared to all of the single antidiabetic drugs. However, both the metformin-glyburide and rosiglitazone-glyburide groups showed significantly greater reductions in glucose levels following olanzapine than with single drug treatment alone for metformin or rosiglitazone, bringing glucose levels down to values equivalent to vehicle-only treated animals. These findings indicate that further study of antidiabetic dual-drug combinations in patients treated with antipsychotic drugs is warranted.

Low glibenclamide concentrations affect endoplasmic reticulum stress in INS-1 cells under glucotoxic or glucolipotoxic conditions

BACKGROUND/AIMS

β-Cell apoptosis caused by increased endoplasmic reticulum (ER) stress is an important pathogenic component of type 2 diabetes mellitus. In theory, sulfonylureas, used for the treatment of diabetes, can contribute to ER stress. We assessed changes in ER stress in pancreatic β-cells under glucotoxic or glucolipotoxic conditions using low concentrations of the sulfonylurea, glibenclamide (GB).

METHODS

Low concentrations of GB (10 or 100 nM) were added to INS-1 cells cultured under glucotoxic or glucolipotoxic conditions. The degree of viability, level of apoptosis and levels of markers associated with ER stress were measured.

RESULTS

Apoptosis decreased in response to low concentrations of GB under glucolipotoxic but not glucotoxic conditions. Most ER stress markers decreased upon the addition of GB. Under glucotoxic conditions, changes in the levels of ER stress markers were not consistent. However, all decreased significantly under glucolipotoxic conditions.

CONCLUSIONS

Low concentrations of GB exerted antiapoptotic effects through the attenuation of ER stress under glucolipotoxic conditions.

The Effects of Glyburide on Apoptosis and Endoplasmic Reticulum Stress in INS-1 Cells in a Glucolipotoxic Condition

BACKGROUND

β-cell death due to endoplasmic reticulum (ER) stress has been regarded as an important pathogenic component of type 2 diabetes. The possibility has been suggested that sulfonylurea, currently being used as one of the main oral hypoglycemic agents of type 2 diabetes, increases ER stress, which could lead to sulfonylurea failure. The authors of the present study examined ER stress of β-cells in a glucolipotoxic condition using glyburide (GB) in an environment mimicking type 2 diabetes.

METHODS

Apoptosis was induced by adding various concentrations of GB (0.001 to 200 µM) to a glucolipotoxic condition using 33 mM glucose, and the effects of varied concentrations of palmitate were evaluated via annexin V staining. The markers of ER stress and pro-apoptotic markers were assessed by Western blotting and semi-quantitative reverse transcription-polymerase chain reaction. Additionally, the anti-apoptotic markers were evaluated.

RESULTS

Addition of any concentration of GB in 150 µM palmitate and 33 mM glucose did not increase apoptosis. The expression of phosphorylated eukaryotic initiation factor (eIF-2α) was increased and cleaved caspase 3 was decreased by adding GB to a glucolipotoxic condition. However, other ER stress-associated markers such as Bip-1, X-box binding protein-1, ATF-4 and C/EBP-homologous protein transcription factor and anti-apoptotic markers phosphor-p85 phosphatidylinositol 3-kinase and phosphorylation of Akt did not change significantly.

CONCLUSION

GB did not show further deleterious effects on the degree of apoptosis or ER stress of INS-1 cells in a glucolipotoxic condition. Increased phosphorylation of eIF-2α may attenuate ER stress for adaptation to increased ER protein load.

Glyburide prevents isoflurane's reducing effects on hydroxyl radical formation in the postischemic reperfused rat heart

BACKGROUND

The role of K(ATP) channels in isoflurane's reducing effects on oxygen free radical formation are not well known.

OBJECTIVES

To investigate whether glyburide, an ATP-regulated potassium (K(ATP)) channel blocker, abolishes isoflurane-induced cardioprotective effects and whether it affects hydroxyl radical formation in the postischemic reperfused heart.

ANIMALS AND METHODS

Thirty-nine male Wistar rats were divided into four groups: group C (control, n=10), group I (isoflurane, n=9), group G (glyburide, n=10) and group GI (glyburide and isoflurane, n=10). The hearts were perfused as a Neely's working heart model. Afterwards, global heart ischemia was induced for 15 min followed by reperfusion for 20 min. The formation of hydroxyl radicals in the coronary effluent and heart was measured with high performance liquid chromatography.

RESULTS

Isoflurane alone and glyburide alone produced significant decreases in the duration of ventricular fibrillation during reperfusion (group C 452+/-345, group I 247+/-60, group G 261+/-135 s; P<0.05). In the presence of glyburide, isoflurane did not further decrease the duration of arrhythmia (group GI 230+/-48 s). Isoflurane reduced hydroxyl radical formation significantly in the coronary effluent during ischemia and reperfusion, but this was prevented by glyburide.

CONCLUSION

The results suggest that isoflurane reduces hydroxyl radical formation, at least in part, through activation of K(ATP) channels.