Zinc Protoporphyrin Polymeric Nanoparticles: Potent Heme Oxygenase Inhibitor for Cancer Therapy

Purpose

Oxidation therapy is an antitumor strategy in which, apoptosis or necrosis is caused by either excess delivery of reactive oxygen species (ROS) as an oxidant or anti-oxidant inhibition. Heme oxygenase (HO) is an anti-oxidant enzyme that plays an important role in cell growth and proliferation. The purpose of this study was to prepare poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) loaded with zinc protoporphyrin (ZnPP) to deliver the HO inhibitor into tumor.

Methods

PLGA NPs were prepared using nanoprecipitation technique and their characteristics were optimized by Box-Behnken experimental design. Scanning electron microscopy and in vitro studies consisting of drug release, HO inhibitory effect, cytotoxicity and cellular uptake followed by in vivo biodistribution and blood cytotoxicity were carried out. Internalization of coumerin-6 loaded NPs by PC3 cells was visualized by confocal laser scanning microscopy beside quantitatively analysis.

Results

NPs average size, entrapment efficiency and drug loading were 100.12?±?5.345 nm, 55.6%?±?2.49 and 7.98%?±?0.341 respectively. Equal HO inhibitory effect of NPs compared to free ZnPP was observed. The IC₅₀ value of ZnPP-NPs for PC3 human prostate cancer cells was found to be 2.14?±?0.083 μM.

Conclusion

In conclusion, ZnPP loaded PLGA NPs could exhibit enough HO inhibitory effect against cancer cells to be considered as a promising candidate for cancer treatment investigation.     

LHRH-Conjugated Micelles for Targeted Delivery of Antiandrogen to Treat Advanced Prostate Cancer

Purpose

Our objective was to synthesize LHRH-conjugated amphiphilic copolymer for micellar delivery of CBDIV17, a novel antiandrogen for treating prostate cancer.

Methods

LHRH-PEG-b-p(CB-co-LA) was synthesized by opening polymerization of carbonate (CB), lactide (LA), and HOOC-PEG-OH followed by conjugation with LHRH analogue. Bicalutamide analogue CBIDV17 loaded micelles were formulated by film hydration method, and characterized for critical micelle concentration (CMC), drug loading and in vitro drug release. Formulations were tested on LNCaP and C4-2 cells for cellular uptake, induction of apoptosis, viability and dowregulation of androgen receptor (AR). In vivo studies were performed in ectopic tumor bearing athymic nude mice after tail vein injection at a dose of 10 mg/kg. Tumor volume and body weight were measured for 25 days followed by immunohistochemistry (IHC) of tumor samples for Ki-67, caspase-3, and prostate specific antigen (PSA).

Results

HOOC-PEG-b-p(CB-co-LA) and LHRH-PEG-b-p(CB-co-LA) were characterized by ¹HNMR and used for preparing micelles, which had a mean particle size of 75.60?±?2.25 and 72.64?±?1.15 nm, respectively and CBDIV17 loading of 4.6% w/w. LHRH conjugated micelles showed higher cellular uptake, cytotoxicity, and apoptosis in LNCaP and C4-2 cells compared to non-targeted micelles. CBDIV17 loaded LHRH micelles more efficiently inhibited the proliferation and induced apoptosis of tumor cells according to Ki-67, caspase-3, and PSA expression. There was significant inhibition of tumor growth with the treatment of CBDIV17 loaded LHRH-conjugated micelles.

Conclusion

These results demonstrated that LHRH-b-PEG-p(CB-co-LA) micelles have the potential for targeted delivery of CBDIV17 to treat advanced prostate cancer.     

Vaccine Delivery to the Oral Cavity Using Coated Microneedles Induces Systemic and Mucosal Immunity

Purpose

The objective of this study is to evaluate the feasibility of using coated microneedles to deliver vaccines into the oral cavity to induce systemic and mucosal immune responses.

Method

Microneedles were coated with sulforhodamine, ovalbumin and two HIV antigens. Coated microneedles were inserted into the inner lower lip and dorsal surface of the tongue of rabbits. Histology was used to confirm microneedle insertion, and systemic and mucosal immune responses were characterized by measuring antigen-specific immunoglobulin G (IgG) in serum and immunoglobulin A (IgA) in saliva, respectively.

Results

Histological evaluation of tissues shows that coated microneedles can penetrate the lip and tongue to deliver coatings. Using ovalbumin as a model antigen it was found that the lip and the tongue are equally immunogenic sites for vaccination. Importantly, both sites also induced a significant (p?IgA in saliva compared to pre-immune saliva. Microneedle-based oral cavity vaccination was also compared to the intramuscular route using two HIV antigens, a virus-like particle and a DNA vaccine. Microneedle-based delivery to the oral cavity and the intramuscular route exhibited similar (p?>?0.05) yet significant (p?IgG in serum. However, only the microneedle-based oral cavity vaccination group stimulated a significantly higher (p?IgA response in saliva, but not intramuscular injection.

Conclusion

In conclusion, this study provides a novel method using microneedles to induce systemic IgG and secretory IgA in saliva, and could offer a versatile technique for oral mucosal vaccination. Figure

?     

Oral Delivery of Glucagon Like Peptide-1 by a Recombinant Lactococcus lactis

Purpose

To develop a live oral delivery system of Glucagon like peptide-1 (GLP-1), for the treatment of Type-2 Diabetes.

Methods

LL-pUBGLP-1, a recombinant Lactococcus lactis (L. lactis)) transformed with a plasmid vector encoding GLP-1 cDNA was constructed and was used as a delivery system. Secretion of rGLP-1 from LL-pUBGLP-1 was characterized by ELISA. The bioactivity of the rGLP-1 was examined for its insulinotropic activity on HIT-T15 cells. Transport of rGLP-1 across MDCK cell monolayer when delivered by LL-pUBGLP-1 was studied. The therapeutic effect of LL-pUBGLP-1 after oral administration was investigated in ZDF rats.

Results

DNA sequencing and ELISA confirmed the successful construction of the LL-pUBGLP-1 and secretion of the active form of rGLP-1. In vitro insulinotropic studies demonstrated that LL-pUBGLP-1 could significantly (p?GLP-1 transport rate across the MDCK cell monolayer was increased by eight times (p?p?0-11h (2.5 times, p?Conclusion The present study demonstrates that L. lactis when genetically modified with a recombinant plasmid can be used for the oral delivery of GLP-1.     

Effect of two-linked mutations of the FMO3 gene on itopride metabolism in Chinese healthy volunteers

Purpose

Itopride is an effective gastroprokinetic agent mainly used for the treatment of functional dyspepsia. Flavin-containing monooxygenase 3 (FMO3) has been confirmed to be the key enzyme involved in the main itopride metabolic pathway. We investigated whether the FMO3 genotypes can affect itopride metabolism in Chinese healthy volunteers.

Methods

Twelve healthy volunteers who had been genotyped for FMO3 gene were selected to participate in our study. Volunteers were given 50 mg itopride orally and then blood samples were collected from 0 to 24 h. The plasma concentrations of itopride and itopride N-oxide were determined by HPLC-MS/MS method.

Results

Itopride and itopride N-oxide both exhibit FMO3 genotype-dependent pharmacokinetic profiles. The area under the plasma concentration–time curve (AUC) of itopride increased by 127.82?±?41.99 % (P?P?FMO3 hhdd subjects (n?=?6) compared with the HHDD group (n?=?6). The CL/F value was lower in the hhdd group than that in the HHDD group (36.60?±?7.06 vs. 80.20?±?15.34 L/h, P?1/2 value and t_max of itopride and itopride N-oxide were observed between these two genotypes.

Conclusion

The FMO3 allele can significantly affect the metabolism of itopride. The pharmacokinetic parameters of both itopride and itopride N-oxide were significantly different between these two genotypes.     

Yohimbine administration and cue-reactivity in cocaine-dependent individuals

Rationale

Preclinical studies suggest that stress potentiates cue-induced cocaine seeking and that this effect is more pronounced in females. These findings have not been characterized in clinical populations.

Objectives

The objectives of this study were to examine the impact a pharmacological stressor, alpha-2 adrenergic receptor antagonist yohimbine, on the subjective, endocrine, and physiologic responses to drug-paired cues cocaine-dependent men and women.

Methods

In a double-blind placebo-controlled cross-over study, cocaine-dependent men (n?=?32), cocaine-dependent women (n?=?30), control men (n?=?32), and control women (n?=?25) received either yohimbine or placebo prior to two cocaine cue exposure sessions.

Results

Yohimbine increased ratings of anxiety both before (p?p?=?0.035) cues, and the post-cue increase in anxiety was more pronounced in women (p?=?0.001). Yohimbine also significantly increased craving, compared with placebo (p?p?=?0.006). Yohimbine also increased salivary cortisol (p?p?=?0.003) levels, regardless of diagnostic group. Women had a significantly greater heart rate response following yohimbine as compared with men (p?Conclusions Stress may increase the salience of cocaine cues for cocaine-dependent women as compared with men. This suggests gender differences in vulnerability to craving and relapse under stressful conditions.     

Tumor-Targeted Responsive Nanoparticle-Based Systems for Magnetic Resonance Imaging and Therapy

Purpose

Design and synthesis of a tumor responsive nanoparticle-based system for imaging and treatment of various cancers.

Methods

Manganese oxide nanoparticles (Mn₃O₄ NPs) were synthesized and modified with LHRH targeting peptide or anti-melanoma antibodies (cancer targeting moieties) and a MMP2 cleavable peptide (a possible chemotactic factor). Nanostructured lipid carriers (NLCs) were used to entrap the BRAF inhibitor, vemurafenib, and enhance cytotoxicity of the drug. Size distribution, stability, drug entrapment, cytotoxicity and genotoxicity of synthesized nanoparticles were studied in vitro. Enhancement of MRI signal by nanoparticles and their body distribution were examined in vivo on mouse models of melanoma, ovarian and lung cancers.

Results

Uniform, stable cancer-targeted nanoparticles (PEGylated water-soluble Mn₃O₄ NPs and NLCs) were synthesized. No signs of cyto-,genotoxicity and DNA damage were detected for nanoparticles that do not contain an anticancer drug. Entrapment of vemurafenib into nanoparticles significantly enhanced drug toxicity in cancer cells with targeted V600E mutation. The developed nanoparticles containing LHRH and MMP2 peptides showed preferential accumulation in primary and metastatic tumors increasing the MRI signal in mice with melanoma, lung and ovarian cancers.

Conclusions

The proposed nanoparticle-based systems provide the foundation for building an integrated MRI diagnostic and therapeutic approach for various types of cancer.     

Development of EGFR-Targeted Nanoemulsion for Imaging and Novel Platinum Therapy of Ovarian Cancer

Purpose

Platinum-based chemotherapy is the treatment of choice for malignant epithelial ovarian cancers, but generalized toxicity and platinum resistance limits its use. Theranostic nanoemulsion with a novel platinum prodrug, myrisplatin, and the pro-apoptotic agent, C₆-ceramide, were designed to overcome these limitations.

Methods

The nanoemulsions, including ones with an EGFR binding peptide and gadolinium, were made using generally regarded as safe grade excipients and a high shear microfluidization process. Efficacy was evaluated in ovarian cancer cells, SKOV3, A2780 and A2780_CP.

Results

The nanoemulsion with particle size <150 nm were stable in plasma and parenteral fluids for 24 h. Ovarian cancer cells in vitro efficiently took up the non-targeted and EGFR-targeted nanoemulsions; improved cytotoxicity was observed for the these nanoemulsions with the latter showing a 50-fold drop in the IC₅₀ in SKOV3 cells as compared to cisplatin alone. The addition of gadolinium did not affect cell viability in vitro, but showed relaxation times comparable to Magnevist^®.

Conclusion

The myrisplatin/C₆-ceramide nanoemulsion synergistically enhanced in vitro cytotoxicity. An EGFR binding peptide addition further increased in vitro cytotoxicity in EGFR positive cancer cells. The diagnostic version showed MR imaging similar to the clinically relevant Magnevist® and may be suitable as a theranostic for ovarian cancer.     

The Antitumor Effect of a New Docetaxel-Loaded Microbubble Combined with Low-Frequency Ultrasound In Vitro: Preparation and Parameter Analysis

Purpose

To develop a novel docetaxel (DOC)-loaded lipid microbubbles (MBs) for achieving target therapy and overcoming the poor water-solubility drawback of DOC.

Methods

A novel DOC-loaded microbubble (DOC + MB) was prepared by lyophilization and the physicochemical properties including ultrasound contrast imaging of the liver were measured. The anti-tumor effect of the DOC + MBs combined with low-frequency ultrasound (LFUS; 0.8Hz, 2.56 W/cm², 50% cycle duty) on the DLD-1 cancer cell line was examined using an MTT assay.

Results

The physicochemical properties of the two tested formats of DOC + MBs (1.0 mg and 1.6 mg) was shown: concentration, (6.74?±?0.02)?×?10⁸ bubbles/mL and (8.27?±?0.15)?×?10⁸ bubbles/mL; mean size, 3.296?±?0.004 μm and 3.387?±?0.005 μm; pH value, 6.67?±?0.11 and 6.56?±?0.05; release rate, 3.41% and 12.50%; Zeta potential, ?37.95?±?7.84 mV and ?44.35?±?8.70 mV; and encapsulation efficiency, 54.9?±?6.21% and 46.3?±?5.69%, respectively. Compared with SonoVue, the DOC + MBs similarly enhanced the echo signal of the liver imaging. The anti-tumor effect of the DOC + MBs/LFUS group was significantly better than that of DOC alone and that of the normal MBs/LFUS groups.

Conclusions

The self-made DOC + MBs have potential as a new ultrasound contrast agent and drug-loaded microbubble, and can obviously enhance the antitumor effect of DOC under LFUS exposure.     

Efficacy and safety of canagliflozin in subjects with type 2 diabetes: systematic review and meta-analysis

Purpose

To assess the efficacy and safety of the novel sodium glucose co-transporter 2 (SGLT2) inhibitor—canagliflozin for type 2 diabetes (T2DM).

Methods

A search of Medline (1946–January 2014), Embase (1950–January 2014), and The Cochrane Library for randomized controlled trials of canagliflozin compared to placebo or active comparator in T2DM was performed. Clinical Trials website and unpublished U.S. Food and Drug Administration data were also searched.

Results

Ten trials including 6,701 patients were analyzed. Compared with placebo, canagliflozin produced absolute reductions in glycated hemoglobin A_1c levels when used as monotherapy (weighted mean difference (WMD) ?1.08 %, 95 % confidence interval (CI) [?1.25 to ?0.90], p?p?HbA1c by ?0.21 % (WMD, 95 %CI [?0.33 to ?0.08], p?=?0.001). Canagliflozin led to greater body weight loss (vs. placebo, WMD ?2.81 kg, 95 %CI [?3.26 to ?2.37]; vs. active comparators, WMD ?3.49 kg, 95 %CI [?4.86 to ?2.12]). Hypoglycemia with canagliflozin was similar to placebo or sitagliptin, and was lower than glimepiride (risk ratio (RR) 0.15, 95 %CI [0.10 to 0.22]). Genital tract infections were more common with canagliflozin (vs. placebo, RR 3.76, 95 %CI [2.23 to 6.35]; vs. active comparators, RR 4.95, 95 %CI [3.25 to 7.52]). Similar incidences of urinary tract infections were noted with canagliflozin compared with control groups.

Conclusion

Canagliflozin led to improvements in reducing glycated hemoglobin A_1c levels and body weight with low risk of hypoglycemia in patients with T2DM. Common adverse effects including genital tract infections and osmotic diuresis-related AEs were identified and reviewed. Risks of cardiovascular events are even less certain, and more data on long-term effects are needed.     

Chitosan-Based Hybrid Nanocomplex for siRNA Delivery and Its Application for Cancer Therapy

Purpose

Chitosan, a natural and biocompatible cationic polymer, is an attractive carrier for small interfering RNA (siRNA) delivery. The purpose of this study was to develop a chitosan-based hybrid nanocomplex that exhibits enhanced physical stability in the bloodstream compared with conventional chitosan complexes. Hybrid nanocomplexes composed of chitosan, protamine, lecithin, and thiamine pyrophosphate were prepared for systemic delivery of survivin (SVN) siRNA.

Methods

Physicochemical properties of the nanoparticles including mean diameters and zeta potentials were characterized, and target gene silencing and cellular uptake efficiencies of the siRNA nanocomplexes in prostate cancer cells (PC-3 cells) were measured. In vivo tumor targetability and anti-tumor efficacy by systemic administration were assessed in a PC-3 tumor xenograft mouse model by near-infrared fluorescence (NIRF) imaging and tumor growth monitoring, respectively.

Results

Mean diameters of the SVN siRNA-loaded hybrid nanocomplex (GP-L-CT) were less than 200 nm with a positive zeta potential value in water and were maintained without aggregation in culture media and 50% fetal bovine serum. SVN expression in PC-3 cells was reduced to 21.9% after treating with GP-L-CT. The tumor targetability and growth inhibitory efficacies of GP-L-CT supported the use of this novel hybrid nanocomplex as a cancer therapeutic and as a theranostic system for systemic administration.

Conclusions

A chitosan-based hybrid nanocomplex was successfully developed for the systemic delivery of SVN siRNA, which could serve as an alternative to cationic polymeric nanoparticles that are unstable in serum.     

Phosphatidylinositol 4,5-bisphosphate depletion fails to affect neurosteroid modulation of GABAA receptor function

Rationale

Neurosteroids and likely other lipid modulators access transmembrane sites on the GABA_A receptor (GABA_AR) by partitioning into and diffusing through the plasma membrane. Therefore, specific components of the plasma membrane may affect the potency or efficacy of neurosteroid-like modulators. Here, we tested a possible role for phosphatidylinositol 4,5-bisphosphate (PIP2), a phospholipid that governs activity of many channels and transporters, in modulation or function of GABA_ARs.

Objectives

In these studies, we sought to deplete plasma-membrane PIP2 and probe for a change in the strength of potentiation by submaximal concentrations of the neurosteroid allopregnanolone (3α5αP) and other anesthetics, including propofol, pentobarbital, and ethanol. We also tested for a change in the behavior of negative allosteric modulators pregnenolone sulfate and dipicrylamine.

Methods

We used Xenopus oocytes expressing the ascidian voltage-sensitive phosphatase (Ci-VSP) to deplete PIP2. Voltage pulses to positive membrane potentials were used to deplete PIP2 in Ci-VSP-expressing cells. GABA_ARs composed of α1β2γ2L and α4β2δ subunits were challenged with GABA and 3α5αP or other modulators before and after PIP2 depletion. KV7.1 channels and NMDA receptors (NMDARs) were used as positive controls to verify PIP2 depletion.

Results

We found no evidence that PIP2 depletion affected modulation of GABA_ARs by positive or negative allosteric modulators. By contrast, Ci-VSP-induced PIP2 depletion depressed KV7.1 activation and NMDAR activity.

Conclusions

We conclude that despite a role for PIP2 in modulation of a wide variety of ion channels, PIP2 does not affect modulation of GABA_ARs by neurosteroids or related compounds.     

5α-reductase type I expression is downregulated in the prefrontal cortex/Brodmann’s area 9 (BA9) of depressed patients

Rationale

The implications of the neurosteroid 3α-hydroxy-5α-pregnan-20-one [allopregnanolone (Allo)] in neuropsychiatric disorders have been highlighted in several recent clinical investigations. For instance, Allo levels are decreased in the cerebrospinal fluid (CSF) of patients with posttraumatic stress disorder (PTSD) and major unipolar depression. Neurosteroidogenic antidepressants [i.e., selective brain steroidogenic stimulants (SBSSs)], including fluoxetine and analogs, correct this decrease in a manner that correlates with improved depressive symptoms. Allo positively and allosterically modulates GABA action at postsynaptic and extrasynaptic GABA_A receptors. It is synthesized in both the human and rodent brain cortices by principal glutamatergic pyramidal neurons from progesterone by the sequential action of 5α-reductase type I (5α-RI), which is the rate-limiting step enzyme in Allo biosynthesis, and 3α-hydroxysteroid dehydrogenase (3α-HSD), which converts 5α-dehydroprogesterone into Allo.

Hypothesis

We thus hypothesized that decreased CSF levels of Allo in depressed patients could reflect a brain dysfunction of 5α-RI.

Methods

In a pilot study of samples from six patients per group [six depressed patients and six nonpsychiatric subjects (NPS)], we studied the expression of 5α-RI messenger RNA (mRNA) in prefrontal cortex Brodmann’s area 9 (BA9) and cerebellum from depressed patients obtained from the Maryland Brain Collection at the Maryland Psychiatric Research Center (Baltimore, MD) that were age-matched with NPS.

Results

The levels of 5α-RI mRNA were decreased from 25?±?5.8 in NPS to 9.1?±?3.1 fmol/pmol neuronal specific enolase (NSE) (t_1,10?=?2.7, P?=?0.02) in depressed patients. These differences are absent in the cerebellum of the same patients. The levels of neurosteroids were determined in the prefrontal cortex BA9 of depressed patients obtained from the Stanley Foundation Brain Bank Neuropathology Consortium, Bethesda (MD). The BA9 levels of Allo in male depressed patients failed to reach statistical difference from the levels of NPS (1.63?±?1.01 pg/mg, n?=?8, in NPS and 0.82?±?0.33 pg/mg, n?=?5, in nontreated depressed patients). However, depressed patients who had received antidepressant treatment (three patients SSRI and one TCA) exhibited increased BA9 Allo levels (6.16?±?2.5 pg/mg, n?=?4, t_1,9?=?2.4, P?=?0.047) when compared with nontreated depressed patients.

Conclusions

Although in a small number of patients, this finding is in-line with previous reports in the field that have observed an increase of Allo levels in CSF and plasma of depressed patients following antidepressant treatment. Hence, the molecular mechanisms underlying major depression may include a GABAergic neurotransmission deficit caused by a brain Allo biosynthesis downregulation, which can be normalized by SBSSs.     

Preclinical Pharmacokinetic and Pharmacodynamic Evaluation of Novel Anticancer Agents, ON01910.Na (Rigosertib, Estybon?) and ON013105, for Brain Tumor Chemotherapy

Purpose

To evaluate a mitotic inhibitor, ON01910.Na, as a potential chemotherapeutic agent for brain tumors using a series of PK/PD studies, which led to the evaluation of its structural analog, ON013105, a prodrug of the more lipophilic product, ON013100.

Methods

Systemic PK characterization of ON01910 and ON013105 was completed in healthy mice. Using an orthotopic U87 glioma mouse model, brain and brain tumor distribution under steady-state conditions were evaluated for ON01910.Na and ON013105/ON013100; anticancer potential following a multiple-dose schedule of 250?mg/kg/day IP for 7?days was evaluated for ON01910.Na.

Results

ON01910 exhibited low brain and brain tumor distribution with quasi-steady-state brain/plasma (Css_brain/Css_plasma) and brain tumor/plasma (Css_{brain tumor}/Css_plasma) concentration ratios of 0.03?±?0.02 and 0.14?±?0.08, respectively. Significant antiangiogenic potential and antiproliferative capacity of ON01910 in the intracerebral model was absent. ON013100 showed high brain and brain tumor penetration with Css_brain/Css_plasma and Css_{brain tumor}/Css_plasma ratios of 0.92?±?0.26 and 1.35?±?0.40, respectively; its prodrug ON013105 showed negligible brain and brain tumor penetration.

Conclusions

ON013105, not ON01910.Na, was identified as a potential anticancer drug candidate for further investigation in brain tumor chemotherapy based on the properties of ON013100.     

Add-on Ezetimibe Reduces Small Dense Low-Density Lipoprotein Cholesterol Levels Without Affecting Absorption of Eicosapentaenoic Acid in Patients with Coronary Artery Disease: A Pilot Study

Background

Residual risk of cardiovascular disease from increased small dense low-density lipoprotein (sdLDL)-cholesterol levels and low n-3 polyunsaturated fatty acid (PUFA) levels is a considerable therapeutic issue. The purpose of this study was to evaluate the effect of ezetimibe as an add-on to statins and supplemental eicosapentaenoic acid (EPA) on sdLDL cholesterol and absorption of EPA in patients with coronary artery disease.

Methods

The study population consisted of ten male patients who were concurrently receiving statins and EPA 1,800 mg/day. Serum lipids and PUFAs, including EPA and arachidonic acid, were measured in blood samples collected before ezetimibe (baseline), 4 weeks after starting 10-mg/day ezetimibe, and 4 weeks after discontinuing ezetimibe.

Results

Ezetimibe significantly decreased sdLDL-cholesterol levels after 4 weeks of treatment (baseline 35 ± 13 mg/dl; treatment 27 ± 9 mg/dl), but the levels returned to baseline after discontinuation of ezetimibe (37 ± 13 mg/dl). The concentration of EPA did not significantly change during the study.

Conclusion

Ezetimibe shows great promise as an add-on therapy to statins to reduce sdLDL-cholesterol-related residual risk of cardiovascular disease without affecting absorption of supplemental EPA in patients with coronary artery disease.     

Adrenal steroid hormones and ethanol self-administration in male rhesus macaques

Rationale

Hypothalamic-pituitary-adrenal (HPA) axis hormones have neuroactive metabolites with receptor activity similar to ethanol.

Objectives

The present study related HPA hormones in naïve monkeys to ethanol self-administration.

Methods

Morning plasma adrenocorticotropic hormone (ACTH), cortisol, deoxycorticosterone (DOC), aldosterone, and dehydroepiandrosterone-sulfate (DHEA-S) were measured longitudinally in male rhesus macaques (Macaca mulatta) induced to drink ethanol followed by access to ethanol (4 %?w/v, in water) and water 22 h/day for 12 months.

Results

During ethanol access, DOC increased among non-heavy (average intake over 12 months ≤3.0 g/kg/day, n?=?23) but not among heavy drinkers (>3.0 g/kg/day, n?=?9); aldosterone was greater among heavy drinkers after 6 months. The ratio of DOC/aldosterone decreased only among heavy drinkers after 6 or12 months of ethanol self-administration. ACTH only correlated significantly with DHEA-S, the ratio of cortisol/DHEA-S and DOC after the onset of ethanol access, the former two just in heavy drinkers. Baseline hormones did not predict subsequent ethanol intake over 12 months, but baseline DOC correlated with average blood-ethanol concentrations (BECs), among all monkeys and heavy drinkers as a group. During ethanol access, aldosterone and DOC correlated and tended to correlate, respectively, with 12-month average ethanol intake.

Conclusions

Ethanol self-administration lowered ACTH and selectively altered its adrenocortical regulation. Mineralocorticoids may compensate for adrenocortical adaptation among heavy drinkers and balance fluid homeostasis. As DOC was uniquely predictive of future BEC and not water intake, to the exclusion of aldosterone, GABAergic neuroactive metabolites of DOC may be risk factors for binge drinking to intoxication.     

In Vitro and In Vivo Biological Evaluation of O-Carboxymethyl Chitosan Encapsulated Metformin Nanoparticles for Pancreatic Cancer Therapy

Purpose

In vitro anticancer effect and in vivo biodistribution and biocompatibility of metformin encapsulated O-Carboxymethyl chitosan nanoparticles were evaluated for its application as pancreatic cancer therapy.

Methods

In vitro studies such as cell migration assay, clonogenic assay, cell cycle analysis and qRT-PCR analysis were done in pancreatic cancer cells (MiaPaCa-2) treated with O-CMC-metformin NPs for evaluating its anticancer potential. In vivo biodistribution studies were carried out by NIR imaging of O-CMC-metformin NPs after tagging it with ICG. In vivo biocompatibility of the NPs was assessed by histopathology analysis of organs from mice administered with the NPs.

Results

In vitro cell migration assay showed marginal effect of NPs on migration property of pancreatic cancer cells (MiaPaCa-2). In vitro clonogenic assay established that the O-CMC-metformin NPs reduced colony formation ability of the cancer cells. While cell cycle analysis showed that the O-CMC-metformin NPs had only minor effect on progression of cell cycle in the cancer cells. qRT-PCR analysis exhibited reduced mRNA expression of p21, vanin 1 and MMP9 in pancreatic cancer cells treated with the nanoparticles. In vivo NIR imaging study showed normal biodistribution pattern of the intravenously injected O-CMC-metformin NPs suggesting normal clearance rate of nanoparticles and no adverse toxicity to the organs.

Conclusions

The biocompatible O-CMC-metformin NPs with anticancer potential and capability for normal biodistribution can be beneficial for the treatment of pancreatic cancer.     

Prefrontal dopamine D1 receptors and working memory in schizotypal personality disorder: a PET study with [11C]NNC112

Rationale

Schizotypal personality disorder (SPD) is associated with working memory (WM) impairments that are similar to those observed in schizophrenia. Imaging studies have suggested that schizophrenia is associated with alterations in dopamine D1 receptor availability in the prefrontal cortex (PFC) that may be related to the WM impairments that characterize this disorder.

Objectives

The aim of this study was to characterize prefrontal D1 receptor availability and its relation to WM performance in SPD.

Methods

We used positron emission tomography (PET) and the radiotracer [¹¹C]NNC112 with 18 unmedicated SPD and 21 healthy control participants; as an index of D1 receptor availability, binding potential (BP) measures (BP_F, BP_ND, and BP_P) were calculated for prefrontal and striatal subregions. To assess WM, SPD participants completed the 2-back and Paced Auditory Serial Addition Test (PASAT).

Results

There were no significant group differences in PFC BP. BP_F and BP_P in the medial PFC were significantly negatively related to PASAT performance (r _s ?=??0.551, p?=?.022 and r _s ?=??0.488, p?=?.047, respectively), but BP was not related to 2-back performance.

Conclusions

In contrast to what has been found in schizophrenia, SPD was not associated with significant alterations in prefrontal D1 receptor availability. Similar to previous schizophrenia findings, however, higher prefrontal D1 receptor availability was associated with poorer WM performance (as measured by the PASAT) in SPD. These findings suggest that schizophrenia and SPD may share a common pathophysiological feature related to prefrontal dopamine functioning that contributes to WM dysfunction, but that in SPD, alterations in D1 may occur only in a subset of individuals and/or to an extent that is minor relative to what occurs in schizophrenia.     

Acylation of Exenatide by Glycolic Acid and its Anti-Diabetic Activities in db/db Mice

Purpose

To prepare acylated exenatide analogues and investigate their biological properties for guiding the development of PLGA formulations of exenatide.

Methods

The acylated exenatide analogues were prepared by reaction with glycolic acid (GA), one constitutional unit of PLGA, and characterized by HPLC-MS/MS and Circular Dichroism (CD). The pharmacokinetic properties and anti-diabetic activities were studied in SD rats and db/db mice, respectively.

Results

Structural characterizations of the acylated products showed that one to four glycolic acids (GAs) were connected to the primary amine groups of exenatide, and there was a conversion of α-helix to β-sheet to some extent. Pharmacokinetic studies in SD rats revealed that acylated exenatides had a similar Tmax with that of the prototype drug, whereas the Cmax and the AUC values of the adducts were significantly decreased. Biological activity tests demonstrated that exenatide and acylated exenatide analogues had similar in vivo antidiabetic activities in terms of controlling blood glucose concentration, HbA1c level, body weight and food intake.

Conclusions

These findings suggest that GA conjugated exenatide had no influence on the peptide efficacy, therefore it’s not necessary to inhibit exenatide acylation in PLGA formulations during the peptide release process.     

Aerosolized Montelukast Polymeric Particles—An Alternative to Oral Montelukast–Alleviate Symptoms of Asthma in a Rodent Model

Purpose

Cysteinyl leukotrienes (CysLTs) propagate inflammatory reactions that result from allergen exposure in asthma. Montelukast, a CysLT type-1 receptor antagonist, disrupts mediator–receptor interactions and minimizes inflammatory response. In this study, we have evaluated anti-asthmatic efficacy of inhalable montelukast-loaded large porous particulate formulations in ovalbumin-induced rat airway inflammation model that mimics asthma.

Methods

The anti-inflammatory effects of a montelukast-loaded formulation were investigated in rats by measuring the total protein content, levels of injury markers and number of inflammatory cells in the bronchoalveolar lavage fluid (BALF). The histopathological studies assessed the morphological and structural changes that occur in asthmatic lungs. Animals were also challenged with methacholine to examine the airway hyper-reactivity.

Results

Compared with healthy animals, asthmatic animals showed a 3.8- and 4.77-fold increase in the protein content and number of inflammatory cells in BALF, respectively. Intratracheal montelukast particles reduced the protein content by 3.3-fold and the number of inflammatory cells by 2.62-fold. Also, montelukast particles reduced the lactate dehydrogenase (LDH) and myeloperoxidase (MPO) levels by a 4.87- and 6.8-fold in BALF, respectively. Montelukast particles reduced the airway wall thickness by 2.5-fold compared with untreated asthmatic lungs. Further, particulate formulation protected the lungs against methacholine-induced bronchial provocation (p?Conclusions Respirable large porous particles containing montelukast alleviated allergen-induced inflammatory response in an animal model and prevented histological changes associated with asthma. Thus montelukast-loaded large porous polylactic acid (PLA) particles could be an aerosolized delivery approach for administration of currently available oral montelukast.