HIF-PHD inhibitor desidustat ameliorates iron deficiency anemia.

Iron deficiency anemia is caused by many pathological conditions like chronic kidney disease (CKD), inflammation, malnutrition and gastrointestinal abnormality. Current treatments that are erythropoiesis stimulating agents (ESAs) and iron supplementation are inadequate and often lead to tolerance and/or toxicity. Desidustat, a prolyl hydroxylase (PHD) inhibitor, is clinically used for the treatment of anemia with CKD. In this study, we investigated the effect of desidustat on iron deficiency anemia (IDA). IDA was induced in C57BL6/J mice by iron deficient diet feeding. These mice were then treated with desidustat (15 mg/kg, PO) and FeSO4 (20 mg/kg) for five weeks and effect of the treatment on hematology, iron homeostasis, and bone marrow histology was observed. Effect of desidustat on iron metabolism in inflammation (LPS)-induced iron deficiency was also assessed. Both, Desidustat and FeSO4, increased MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin), hemoglobin, and HCT (hematocrit) in blood and increased iron in serum, liver, and spleen. Desidustat increased MCHC (mean corpuscular hemoglobin concentration) while FeSO4 treatment did not alter it. FeSO4 treatment significantly increased iron deposition in liver, and spleen, while desidustat increased iron in circulation and demonstrated efficient iron utilization. Desidustat increased iron absorption, serum iron and decreased hepcidin without altering tissue iron, while FeSO4 increased serum and tissue iron by increasing hepcidin in LPS-induced iron deficiency. Desidustat increased erythroid population, especially iron-dependent polychromatic normoblasts and orthochromatic normoblasts, while FeSO4 did not improve cell architecture. PHD inhibition by desidustat improved iron utilization in iron deficiency anemia, by efficient erythropoiesis.

Prolyl hydroxylase inhibitor desidustat protects against acute and chronic kidney injury by reducing inflammatory cytokines and oxidative stress.

Chronic kidney disease (CKD) is associated with activated inflammatory responses. Desidustat, a prolyl hydroxylase (PHD) inhibitor is useful for treatment of anemia associated with CKD, but its effect on the inflammatory and fibrotic changes in CKD is not evaluated. In this study, we investigated the effect of desidustat on the inflammatory and fibrotic changes in preclinical models of acute and chronic kidney injury. Acute kidney injury was induced in male Sprague Dawley rats by ischemia-reperfusion, in which effect of desidustat (15 mg/kg, PO) was estimated. In a separate experiment, male C57 mice were treated with adenine for 14 days to induce CKD. These mice were treated with desidustat (15 mg/kg, PO, alternate day) treatment for 14 days, with adenine continued. Desidustat prevented elevation of serum creatinine, urea, IL-1ß, IL-6, and kidney injury molecule-1 (KIM-1), and elevated the erythropoietin levels in rats that were subjected to acute kidney injury. Mice treated with adenine developed CKD and anemia, and desidustat treatment caused improvement in serum creatinine, urea, and also improved hemoglobin and reduced hepatic and serum hepcidin. A significant reduction in IL-1ß, IL-6, myeloperoxidase (MPO) and oxidative stress was observed by desidustat treatment. Desidustat treatment also reduced renal fibrosis as observed by histological analysis and hydroxyproline content. Desidustat treatment reduced the renal fibrosis and inflammation along with a reduction in anemia in preclinical models of kidney injury, which may translate to protective effects in CKD patients.

The Perspective of Using Flow Cytometry for Unpuzzling Hypoxia-Inducible Factors Signalling.

Hypoxia-inducible factors (HIFs) are transcription factors that are responsible for adapting to the changes in oxygen levels in the cellular environment. HIF activity determines the expression of cellular proteins that control the development and physiology of the cells and pathophysiology of a disease. Understanding the role of specific HIF (HIF-1-3) in cellular function is essential for development of the HIF-targeted therapies. In this review, we have discussed the use of flow cytometry in analysing HIF function in cells. Proper understanding of HIF-signalling will help to design pharmacological interventions HIF-mediated therapy. We have discussed the role of HIF-signalling in various diseases such as cancer, renal and liver diseases, ulcerative colitis, arthritis, diabetes and diabetic complications, psoriasis, and wound healing. We have also discussed protocols that help to decipher the role of HIFs in these diseases that would eventually help to design promising therapies.

HIF Stabilizer Desidustat Protects against Complement-Mediated Diseases.

Complement cascade is a defence mechanism useful for eliminating pathogenic microorganisms and damaged cells. However, activation of alternative complement system can also cause inflammation and promote kidney and retinal disease progression. Inflammation causes tissue hypoxia, which induces hypoxia-inducible factor (HIF) and HIF helps the body to adapt to inflammation. In this study, we investigated the effect of HIF stabilizer desidustat in complement-mediated diseases. Oral administration of desidustat (15 mg/kg) was effective to reduce the kidney injury in mice that was induced by either lipopolysaccharide (LPS), doxorubicin or bovine serum albumin (BSA)-overload. Complement activation-induced membrane attack complex (MAC) formation and factor B activity were also reduced by desidustat treatment. In addition, desidustat was effective against membranous nephropathy caused by cationic BSA and retinal degeneration induced by sodium iodate in mice. C3-deposition, proteinuria, malondialdehyde, and interleukin-1ß were decreased and superoxide dismutase was increased by desidustat treatment in cBSA-induced membranous nephropathy. Desidustat specifically inhibited alternative complement system, without affecting the lectin-, or classical complement pathway. This effect appears to be mediated by inhibition of factor B. These data demonstrate the potential therapeutic value of HIF stabilization by desidustat in treatment of complement-mediated diseases.

Hydrocephalus in achondroplasia: efficacy of endoscopic third ventriculostomy.

OBJECTIVE: Ventriculoperitoneal shunts (VPSs) for hydrocephalus in patients with achondroplasia are known to have a higher failure rate than in other hydrocephalus populations. However, the etiology of hydrocephalus in this group is considered "communicating," and, therefore, potentially not amenable to endoscopic third ventriculostomy (ETV). ETV has, nonetheless, been reported to be successful in a small number of patients with achondroplasia. The authors aimed to investigate the long-term results of ETV in this population. METHODS: Patients with achondroplasia who had undergone surgical treatment for hydrocephalus (ETV or VPS placement) were identified. In patients who had undergone ETV, medical records and neuroimages were reviewed to determine ventricular volumes and frontal and occipital horn ratios (FOHRs) pre- and postoperatively, as well as the incidence of surgical complications and reoperation. Patients who underwent VPS placement were included for historical comparison, and their medical records were reviewed for basic demographic information as well as the incidence of surgical complications and reoperation. RESULTS: Of 114 pediatric patients with achondroplasia referred for neurosurgical consultation, 19 (17%) were treated for hydrocephalus; 10 patients underwent ETV only, 7 patients underwent VPS placement only, and 2 patients had a VPS placed followed by ETV. In patients treated with ETV, ventricular volume and FOHRs were normal, if measured at birth, and increased significantly until the time of the ETV. After ETV, all patients demonstrated significant and sustained decreases in ventricular measurements with surveillance up to 15 years. There was a statistically significant difference in rates of repeat CSF surgery between the ETV and VPS cohorts (0/12 vs 7/9, p < 0.001). CONCLUSIONS: ETV was efficacious, safe, and durable in the treatment of hydrocephalus in patients with achondroplasia. Although many studies have indicated that hydrocephalus in these patients is "communicating," a subset may develop an "obstructive" component that is progressive and responsive to ETV.

Prolyl hydroxylase inhibitor desidustat improves anemia in erythropoietin hyporesponsive state.

Many anemic chronic kidney disease (CKD) patients are refractory to erythropoietin (EPO) effects due to inflammation, deranged iron utilization, and generation of EPO antibodies. This work assessed the effect of desidustat, an inhibitor of hypoxia inducible factor (HIF) prolyl hydroxylase (PHD), on EPO-refractory renal anemia. Sprague Dawley rats were made anemic by cisplatin (5 â€‹mg/kg, IP, single dose) and turpentine oil (5 â€‹mL/kg, SC, once a week). These rats were given recombinant human EPO (rhEPO, 1 â€‹µg/kg) and desidustat (15 or 30 â€‹mg/kg) for eight weeks. Separately, rhEPO (1-5 â€‹µg/kg) was given to anemic rats to sustain the normal hemoglobin levels and desidustat (15 â€‹mg/kg) for eight weeks. In another experiment, the anemic rats were treated rhEPO (5 â€‹µg/kg) for two weeks and then desidustat (15 â€‹mg/kg) for the next two weeks. Dosing of rhEPO was thrice a week, and for desidustat, it was on alternate days. Desidustat inhibited EPO-resistance caused by rhEPO treatment, decreased hepcidin, IL-6, IL-1ß, and increased iron and liver ferroportin. Desidustat reduced EPO requirement and anti-EPO antibodies. Desidustat also maintained normal hemoglobin levels after cessation of rhEPO treatment. Thus, novel prolyl hydroxylase inhibitor desidustat can treat EPO resistance via improved iron utilization and decreased inflammation.

Retrieval of an Intracranially Migrated Dental Injection Needle Through the Foramen Ovale: 2-Dimensional Operative Video.

Dental injection needle migration is a rare complication of orthodontal procedures. When these needles fracture, they typically dislodge into the cervical space or the facial musculature. Migration into the cranial vault is difficult because of the obstacle created by the skull base. We report a rare case of intracranial migration of an anesthetic injection needle through the foramen ovale. A 59-yr-old man underwent the extraction of a right maxillary molar. The distal end of a 25-gauge injection needle broke into his pterygoid musculature, causing him pain while chewing. Vascular imaging obtained after a computed tomography scan of his face showed that the needle had migrated, potentially because of his efforts of mastication, and had traversed the foramen ovale into the middle cranial fossa. The patient started experiencing intermittent right facial numbness, likely due to compression or injury to the right trigeminal nerve. Our oral and maxillofacial colleagues did not believe that the needle could be retrieved from its facial end. The patient elected to undergo the recovery of the needle through a craniotomy given the fact that the object was contaminated and because he was becoming increasingly symptomatic. A right pterional craniotomy was planned. Extradural dissection was performed until the dura going into the foramen ovale was revealed. We could feel the metallic needle under the dural sheath of the trigeminal nerve. The dura was opened sharply directly over the needle. We then proceeded to mobilize the needle into the face, and then pulled it out completely through the craniotomy to avoid injury to the temporal lobe. The patient recovered well and was asymptomatic at the time of discharge. This case report was written in compliance with our institutional ethical review board. Institutional review board (IRB) approval and patient consent were waived in light of the retrospective and deidentified nature of the data presented in accordance with the University of Texas Southwestern (UTSW) IRB.

Activation of GLP-1 and Glucagon Receptors Regulates Bile Homeostasis Independent of Thyroid Hormone.

BACKGROUND: Balanced coagonists of glucagon-like peptide-1 (GLP-1) and glucagon receptors are emerging therapies for the treatment of obesity and diabetes. Such coagonists also regulate lipid metabolism, independent of their body weight lowering effects. Many actions of the coagonists are partly mediated by fibroblast growth factor 21 (FGF21) signaling, with the major exception of bile homeostasis. Since thyroid hormone is an important regulator of bile homeostasis, we studied the involvement of thyroid hormone in coagonist-induced changes in lipid and bile metabolism. METHODS: We evaluated the effect of a single dose of coagonist Aib2 C24 chimera2 at 150 to 10000 µg/kg on tetraiodothyronine (T4) and triiodothyronine (T3) in high-fat diet-induced obese (DIO) mice and chow-fed mice. Repeated dose treatment of coagonist (150 µg/kg, subcutaneously) was assessed in four mice models namely, on lipid and bile homeostasis in DIO mice, propylthiouracil (PTU)-treated DIO mice, methimazole (MTM)-treated DIO mice and choline-deficient, L-amino acid-defined, highfat diet (CDAHFD)-induced nonalcoholic steatohepatitis (NASH). RESULTS: Single dose treatment of coagonist did not alter serum T3 and T4 in chow-fed mice and DIO mice. Coagonist treatment improved lipid metabolism and biliary cholesterol excretion. Chronic treatment of GLP-1 and glucagon coagonist did not alter serum T3 in hypothyroid DIO mice and CDAHFDinduced NASH. Coagonist increased serum T4 in DIO mice after 4 and 40 weeks of treatment, though no change in T4 levels was observed in hypothyroid mice or mice with NASH. CONCLUSION: Our data demonstrate that coagonist of GLP-1 and glucagon receptors does not modulate bile homeostasis via thyroid signaling.

Use of cDNA macroarrays and gene profiling for detection of effects of environmental toxicants.

The method we describe in this chapter describes the synthesis and use of cDNA macroarrays for determining changes in gene expression due to environmental toxicants as well as the methods and materials that are required to do this work. While the details are for investigators working with nontraditional species for which commercial arrays are unavailable, anyone can design and use their own custom arrays using these protocols. We have intentionally left out details for statistical analysis for the arrays as the methods for doing this are still being developed and would need to be specific to the experiment being done. In all, gene macroarrays are a relatively easy way to generate large amounts of data in a short amount of time.

Prolyl Hydroxylase Inhibitors: A Breakthrough in the Therapy of Anemia Associated with Chronic Diseases.

Chronic kidney disease, cancer, chronic inflammatory disorders, nutritional, and genetic deficiency can cause anemia. Hypoxia causes induction of hypoxia-inducible factor (HIF), which stimulates erythropoietin (EPO) synthesis. Prolyl hydroxylase domain (PHD) enzyme inhibition can stabilize hypoxia-inducible factor (HIF). HIF stabilization also decreases hepcidin, a hormone of hepatic origin, which regulates iron homeostasis. PHD inhibitors represent a novel pharmacological treatment of anemia associated with chronic diseases. Many orally active PHD inhibitors like roxadustat, molidustat, vadadustat, and desidustat are in late phase clinical trials. This review discusses the role of PHD inhibitors in the treatment of anemia associated with chronic diseases.

Coagonist of glucagon-like peptide-1 and glucagon receptors ameliorates kidney injury in murine models of obesity and diabetes mellitus.

AIM: To investigate the role of glucagon-like peptide-1 (GLP-1)/glucagon receptors coagonist on renal dysfunction associated with diabetes and obesity. METHODS: Chronic high-fat diet fed C57BL/6J mice, streptozotocin-treated high-fat diet fed C57BL/6J mice and diabetic C57BLKS/J db/db mice were used as models of diabetes-induced renal dysfunction. The streptozotocin-treated high-fat diet fed mice and db/db mice were treated with the GLP-1 and glucagon receptors coagonist (Aib2 C24 Chimera2, 150 µg/kg, sc) for twelve weeks, while in chronic high-fat diet fed mice, coagonist (Aib2 C24 Chimera2, 150 µg/kg, sc) treatment was continued for forty weeks. Kidney function, histology, fibrosis, inflammation, and plasma biochemistry were assessed at the end of the treatment. RESULTS: Coagonist treatment decreased body weight, plasma lipids, insulin resistance, creatinine, blood urea nitrogen, urinary albumin excretion rate and renal lipids. In kidney, expression of lipogenic genes (SREBP-1C, FAS, and SCD-1) was decreased, and expression of genes involved in ß-oxidation (CPT-1 and PPAR-α) was increased due to coagonist treatment. In plasma, coagonist treatment increased adiponectin and FGF21 and decreased IL-6 and TNF-α. Coagonist treatment reduced expression of inflammatory (TNF-α, MCP-1, and MMP-9) and pro-fibrotic (TGF-ß, COL1A1, and α-SMA) genes and also improved histological derangement in renal tissue. CONCLUSION: Coagonist of GLP-1 and glucagon receptors alleviated diabetes and obesity-induced renal dysfunction by reducing glucose intolerance, obesity, and hyperlipidemia.

Racial and Ethnic Disparities in Nasopharyngeal Cancer Survival in the United States.

Objective To determine whether patient race and ethnicity affect nasopharyngeal cancer survival. Study Design Retrospective database analysis. Setting National Cancer Institute's SEER database (Surveillance, Epidemiology, and End Results), 1988-2010. Subjects and Methods Nasopharyngeal carcinoma cases were extracted according to site codes and histology recode-broad groupings. The cohort of 5427 patients was used to calculate disease-specific survival in regard to race and ethnicity. Extracted data were further analyzed through direct comparisons and multivariable Cox regression models controlling for patient, tumor, and treatment characteristics. Results Unadjusted survival curves for all nasopharyngeal carcinomas considered together showed a statistically significant better disease-specific survival for the African American race ( P = .02) and Asian ethnicity ( P = .01) relative to Caucasian patients. The survival advantage for both these groups was eliminated after controlling for the age and sex of the patients. Conclusion African American and Asian patients with nasopharyngeal cancer have better disease-specific survival as compared with Caucasian patients, while Hispanic ethnicity has no effect relative to Caucasians. This disparity is accounted for by diagnosis at an older age in Caucasian patients but remains poorly explained in regard to Hispanic patients.

ZY15557, a novel, long acting inhibitor of dipeptidyl peptidase-4, for the treatment of Type 2 diabetes mellitus.

BACKGROUND AND PURPOSE: Dipeptidyl peptidase (DPP)-4 inhibitors increase levels of glucagon-like peptide-1 (GLP-1) and provide clinical benefit in the treatment of type 2 diabetes mellitus. As longer acting inhibitors have therapeutic advantages, we developed a novel DPP-4 inhibitor, ZY15557, that has a sustained action and long half-life. EXPERIMENTAL APPROACH: We studied the potency, selectivity, efficacy and duration of action of ZY15557, in vitro, with assays of DPP-4 activity. In vivo, the pharmacodymamics and pharmacokinetics of ZY15557 were studied, using db/db mice and Zucker fatty rats, along with normal mice, rats, dogs and non-human primates. KEY RESULTS: ZY15557 is a potent, competitive and long acting inhibitor of DPP-4 (Ki 5.53 nM; Koff 3.2 × 10-4 ·s-1 , half-life 35.8 min). ZY15557 treatment inhibited DPP-4 activity, and enhanced active GLP-1 and insulin in mice and rats, providing dose-dependent anti-hyperglycaemic effects. Anti-hyperglycaemic effects were also observed in db/db mice and Zucker fatty rats. Following oral dosing, ZY15557 significantly inhibited plasma DPP-4 activity, determined ex vivo, in mice and rats for more than 48 h, and for up to 168 h in dogs and non-human primates. Allometric scaling predicts a half-life for ZY15557 in humans of up to 60 h. CONCLUSIONS AND IMPLICATIONS: ZY15557 is a potent, competitive and long acting DPP-4 inhibitor. ZY15557 showed similar DPP-4 inhibition across different species. ZY15557 showed excellent oral bioavailability in preclinical species. It showed a low plasma clearance (CL) and large volume of distribution (Vss ) across species, resulting in an extended half-life.

Is the Inhibition of Dipeptidyl Peptidase-4 (DDP-4) Enzyme Route Dependent and/or Driven by High Peak Concentration?- Seeking Answers with ZYDPLA1, a Novel Long Acting DPP-4 Inhibitor, in a Rodent Model.

ZYDPLA1 is a long acting enzyme dipeptidyl peptidase-4 (DPP-4) inhibitor. The comparative effect of DPP-4 inhibition after intravenous (IV) and oral administration of ZYDPLA1 in a rat model was evaluated to answer the question of route dependency and/or the need of high plasma levels of ZYDPLA1. The study was conducted using parallel design in male Wistar rats for IV/oral route (n=9 and 6, for IV and oral respectively). A single 30 mg/kg dose of ZYDPLA1 was administered. Plasma samples were analysed for ZYDPLA1 concentration and DPP-4 inhibition. Pharmacokinetic analysis was carried out to assess peak concentration, area under the concentration-time curve, total body clearance, elimination half-life, and mean residence time. The PK/PD correlation was performed using standard sigmoidal Emax modelling to derive; maximum effect (Emax) and concentration to exert 50% Emax effect (EC50). ZYDPLA1 showed rapid absorption, high volume of distribution, low clearance, and complete oral bioavailability. The Emax derived after both routes and corresponding PK/PD profile showed comparable DDP-4 inhibition. The EC50 for IV (0.021 µg/mL) was comparable to the oral route (0.019 µg/mL). ZYDPLA1 showed full DPP-4 inhibition without regard to the route of administration. Higher systemic peak levels showed no bearing on the DDP-4 inhibition.

Spontaneous Thrombosis and Subsequent Recanalization of a Developmental Venous Anomaly.

Developmental venous anomalies (DVA) are among the most common congenital malformations of the cerebral angioarchitecture. Spontaneous thrombosis of this entity is rare, and our review of the literature found only 31 reported cases of symptomatic spontaneous thrombosis of developmental venous anomalies. Here, we report a unique case describing the spontaneous thrombosis of a DVA leading to venous infarction and subsequent recanalization. The patient was a previously healthy 21-year-old male who presented with an acute onset of partial seizures. Following negative hypercoagulability studies and along with CT (computed tomography) and MR (magnetic resonance) imaging, the patient was treated with anticoagulant therapy and demonstrated complete functional recovery. Knowledge from our literature review of similar cases combined with the experience gained from this patient's treatment leads us to suggest that spontaneous DVA thrombosis and venous infarction generally has a good outcome despite initially devastating neurologic deficits. Additionally, the rarity of spontaneous DVA thromboses lends itself to the need to identify possible predisposing risk factors, chief amongst these being hypercoagulopathies.

Comparing Radiation Dose from Conventional Fluoroscopy to Intraoperative Cone Beam CT (O-arm) during Percutaneous Lesioning Procedures of the Gasserian Ganglion.

INTRODUCTION: The use of intraoperative CT-guidance during the percutaneous treatment of trigeminal neuralgia has become increasingly popular due to the greater ease of foramen ovale cannulation and decreased procedure times. Concerns regarding radiation dose to the patient, however, remain unaddressed. We sought to compare the emitted radiation dose from fluoroscopy with intraoperative CT for these procedures. METHODS: A retrospective review of percutaneous lesioning procedures for trigeminal neuralgia performed between 2010 until 2012 at our institution was conducted and radiation doses to the patient were recorded. We subsequently simulated four separate percutaneous trigeminal rhizotomies using the O-arm intraoperative CT (Medtronics, Minneapolis, MN, USA) to cannulate the foramen ovale bilaterally in two formalin-fixed cadaver heads. RESULTS: Seventeen successful percutaneous treatments for trigeminal neuralgia were performed during the study period. Eleven procedures containing complete records were included in the final analysis. For procedures using fluoroscopy, the mean dosage was 15.2 mGys (range: 1.15 - 47.95, 95% CI 7.34 - 22.99). Radiation dosage from the O-arm imaging system was 16.55 mGy for all four cases. An unequal variance t-test did not reach statistical significance (p=0.42). CONCLUSIONS: We did not observe a significant difference in radiation dose delivered to subjects when comparing CT-guided foramen ovale cannulation relative to fluoroscopy for percutaneous lesioning of the Gasserian ganglion. Additional study is required under operational settings.

Pharmacological characterization of ZYDPLA1, a novel long-acting dipeptidyl peptidase-4 inhibitor.

OBJECTIVE: Dipeptidyl peptidase-4 (DPP-4) is responsible for degradation of glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP), the endogenous incretins that stimulate glucose-dependent insulin secretion. The objective was to evaluate preclinical profile of a novel DPP-4 inhibitor ZYDPLA1. METHODS: In vitro inhibition potency and selectivity were assessed using recombinant enzymes and/or plasma. In vivo efficacy was determined in oral glucose tolerance test or mixed meal tolerance test in C57BL/6J mice, db/db mice and Zucker fatty rats. Pharmacokinetics/pharmacodynamics was studied in mice, rats, dogs, and non-human primates. RESULTS: ZYDPLA1 is a potent, competitive and long acting inhibitor of DPP-4 (Ki 0.0027 µM; Koff 2.3 × 10(-4 ) s(-1) ). ZYDPLA1 was more than 7000-fold selective for recombinant DPP-4 relative to DPP-8 and DPP-9, and more than 60 000-fold selective relative to fibroblast activation protein (FAP) in vitro. DPP-4 inhibition was comparable across species. In vivo, oral ZYDPLA1 elevated circulating GLP-1 and insulin levels in mice and rats and showed dose-dependent anti-hyperglycemic effect. Anti-hyperglycemic effect was also observed in db/db mice and Zucker fatty rats. ZYDPLA1 showed low clearance, large volume of distribution, and a long half-life with excellent oral bioavailability in all species. It significantly inhibited plasma DPP-4 activity in mice and rats for more than 48 h, and for up to 168 h in dogs and non-human primates. Allometric scaling predicted a half-life in humans of 53 to 166 h. CONCLUSION: ZYDPLA1 is a potent, selective, long-acting oral DPP-4 inhibitor with potential to become once-a-week therapy for treatment of type 2 diabetes mellitus.

Effect of GLP-1 based therapies on diabetic dyslipidemia.

Glucagon-like peptide-1 (GLP-1), is a hormone secreted by small intestine. Consumption of food or glucose stimulates synthesis and secretion of GLP-1 in the bloodstream, which in turn stimulates insulin secretion from pancreas and delays gastric emptying. Owing to the favorable spectrum of effects on reduction of hyperglycemia and body weight, GLP-1 mimetics are intensely pursued as therapies for the treatment of type 2 diabetes (T2DM). Even after intensive control of hyperglycemia, the propensity for cardiovascular disease cannot be totally negated in diabetic patients. A major reason for the cardiovascular disease risk in diabetic patients is underlying dyslipidemia, also termed as diabetic dyslipidemia. It is characterized by high concentrations of triglycerides and LDL cholesterol, and lowered HDL cholesterol in plasma, which are associated with hyperglycemia. Increased insulin resistance gives rise to increased free fatty acids in bloodstream, which is the main reason for the lipid changes appearing in diabetic dyslipidemia. The secondary complications like atherosclerosis and other cardiovascular diseases may be predicted with the blood concentrations of triglycerides and cholesterol, due to the correlation proven in clinic. Hence, new drugs that target diabetic dyslipidemia will always be useful in therapy. Apart from its actions on body weight and glucose, GLP-1 can also regulate cholesterol and triglycerides by numerous ways. Acute and long term treatment with either GLP-1 or its stable analogs reduced fasting as well as postprandial lipids in healthy as well as T2DM patients. GLP-1R signaling reduces VLDL-TG production rate from liver, reduces hepatic TG content by modulating key enzymes of lipid metabolism in liver, and impairs hepatocyte de novo lipogenesis and ß-oxidation. GLP-1 can also modulate reverse cholesterol transport. Apart from these direct effects on lipid metabolism, GLP-1 also reduces atherosclerotic events by inhibiting expression of atherogenic inflammatory mediators, suppressing smooth muscle cell proliferation and stimulating NO production. This review mainly deliberates the association of GLP-1 in lipid regulation via lipid absorption, hepatic cholesterol metabolism, reverse cholesterol transport and progression of atherosclerosis.

Therapeutic potential of coagonists of glucagon and GLP-1.

Dual agonism of glucagon and glucagon-like peptide-1 (GLP-1) receptors reduces body weight without inducing hyperglycemia. In addition, coagonists have demonstrated lipid lowering property, which was independent of their anorectic effect. Similarly, GLP-1 modulates cardiovascular function which is favorable for treatment of myocardial injury, cardiac dysfunction, cardiac arrhythmias, endothelial dysfunction, and blood pressure, while glucagon has a positive impact on heart rate, cardiac output, ventricular contraction and enhances cardiac performance in animals and humans. Hence, researchers focused on combining these attributes of GLP-1 and glucagon in a single molecule, which was termed as a coagonist. Oxyntomodulin is the naturally occurring coagonist of GLP-1 and glucagon. This review focusses on the coagonists under clinical development discussing activities affecting cardiovascular functions, lipid modulation, direct effect on cardiac functions or other related functions. A comparative analysis of the in vitro and in vivo properties of GLP-1, glucagon and the coagonists is also carried out. This review discusses potential of GLP-1 and glucagon coagonists in treatment of cardiovascular and hemodynamic diseases with attention to GLP-1 or glucagon receptor specific properties as well as the interaction between other therapies.

Determination of galantamine hydrobromide in bulk drug and pharmaceutical dosage form by spectrofluorimetry.

AIM: To develop a simple, accurate, sensitive, rapid and precise method for the determination of galantamine hydrobromide in bulk drug and pharmaceutical dosage form. MATERIAL AND METHODS: The method employs wavelength detection and determination of galantamine hydrobromide at excitation wavelength 282 nm and emission wavelength 607 nm in a solution of simple distilled water. RESULT AND CONCLUSION: The method was found to be linear in the range of 2-14 µg/ml having r (2) = 0.9999. The mean accuracy was found to be 98.12% to 99.67%. The intraday and interday precision was found to be 0.18-0.35% and 0.13-0.46%, respectively. The limit of detection was found to be 0.29 µg/ml. The limit of quantification was found to be 0.89 µg/ml. The method was successfully applied for the determination of galantamine hydrobromide in bulk drug as well as pharmaceutical dosage form.