Mechanisms of adverse mammary effect induced by olanzapine and therapeutic interventions in rat model.

BACKGROUND: Olanzapine antagonizes dopamine receptors and is prescribed to treat multiple psychiatric conditions. The main side effect of concern for olanzapine is weight gain and metabolic syndrome. Olanzapine induces hyperprolactinemia, however its effect on the mammary gland is poorly documented. METHODS: Rats received olanzapine by gavage or in drinking water at 1, 3, and 6 mg/kg/day for 5-40 days or 100 days, with and without coadministration of bromocriptine or aripiprazole and using once daily or continuous administration strategies. Histomorphology of the mammary gland, concentrations of prolactin, estradiol, progesterone, and olanzapine in serum, mammary gland and adipose tissue, and mRNA and protein expressions of prolactin receptors were analyzed. RESULTS: In adult and prepubescent female rats and male rats, olanzapine induced significant development of mammary glands in dose- and time-dependent manners, with histopathological hyperplasia of mammary ducts and alveoli with lumen dilation and secretion, marked increase of mammary prolactin receptor expression, a marker of breast tissue, and with mild increase of circulating prolactin. This side effect can be reversed after medication withdrawal, but long-term olanzapine treatment for 100 days implicated tumorigenic potentials indicated by usual ductal epithelial hyperplasia. Olanzapine induced mammary development was prevented with the coaddition of the dopamine agonist bromocriptine or partial agonist aripiprazole, or by continuous administration of medication instead of a once daily regimen. CONCLUSIONS: These results shed light on the previously overlooked effect of olanzapine on mammary development and present experimental evidence to support current clinical management strategies of antipsychotic induced side effects in the breast.

Intoxicación por medicamentos en pacientes pediátricos atendidos en un Hospital terciario en Honduras / Drug poisoning in pediatric patients treated in a tertiary Hospital in Honduras

Antecedentes: Las intoxicaciones en pediatría asociadas a medicamentos representan una importante carga para los sistemas de salud pública. Objetivo: Caracterizar al paciente pediátrico con intoxicación por medicamentos, Servicio de Emergencia de Pediatría, Hospital Escuela, Tegucigalpa, 2019- 2021. Métodos: Estudio observacional descriptivo. Se revisaron expedientes clínicos de pacientes pediátricos atendidos por intoxicación por medicamentos. Los resultados se presentan como cuadros y figuras de frecuencias y porcentajes de las variables estudiadas. La información personal de manejó confidencialmente. Resultados: La proporción hospitalaria de pacientes pediátricos atendidos por intoxicación por medicamentos durante el período del estudio fue 0.08%. La media de la edad 12.6 años (DS+/-5.0). El sexo femenino 77.6% (59/76), procedencia Francisco Morazán 84.2% (64/76); y del ambiente urbano marginal 55.3% (42/76). El nivel de escolaridad fue secundaria incompleta 67.1% (51/76). Además del diagnóstico de intoxicación por medicamentos, se identificaron los diagnósticos de intento suicida y trastorno depresivo 76.3% (58/76), cada uno. La intoxicación fue aguda 97.4% (74/76), intencional 76.3% (58/76). La procedencia del fármaco fue medicación del paciente 44.7% (34/76). El lugar donde ocurrió el evento fue en casa/domicilio del paciente 96.1% (73/76). Se utilizó clonazepam en 30.3% (23), fármaco perteneciente al grupo de las benzodiacepinas. No hubo muertes. Discusión: El paciente pediátrico atendido en el Hospital Escuela por intoxicación por medicamentos se caracterizó como adolescente del sexo femenino, con acceso a medicamentos tipo benzodiacepina en el domicilio, relacionado a depresión e intento suicida. Se recomienda realizar estudios para la identificación de factores de riesgo. Es necesaria la creación de políticas públicas que contribuyan a implementar un abordaje integral de la niñez, adolescencia y la familia...(AU)

Relationship between clock gene expression and CYP2C19 and CYP3A4 with benzodiazepines.

The present study aimed to clarify the expressions and roles of clock genes involved in drug metabolism in patients taking benzodiazepines (BZDs), as well as the drug metabolism regulators controlled by clock genes for each BZD type. The relationships between the expressions of the clock genes BMAL1, PER2, and DBP and the drug-metabolizing enzymes CYP3A4 and CYP2C19 were investigated using livers from BZD-detected autopsy cases. In addition, the effect of BZD exposure on various genes was examined in HepG2 human hepatocellular carcinoma cells. The expressions of DBP, CYP3A4, and CYP2C19 in the liver were lower in the diazepam-detected group than in the non-detected group. Furthermore, BMAL1 expression correlated with CYP2C19 expression. Cell culture experiments showed that the expressions of DBP and CYP3A4 decreased, whereas those of BMAL1 and CYP2C19 increased after diazepam and midazolam exposure. The results of the analyses of autopsy samples and cultured cells suggested that DBP regulates CYP3A4 when exposed to BZD. Understanding the relationship between these clock genes and CYPs may help achieve individualized drug therapy.

An FDA oncology analysis of toxicities associated with PBD-containing antibody-drug conjugates.

With a new generation of antibody-drug conjugates (ADCs) that contain a drug-to-antibody ratio (DAR) of 2, the question remains whether advances in technology have resulted in more stable and tumor-specific ADCs. These ADCs are anticipated to cause minimal systemic exposures of payloads, with toxicities being evident mainly at tumor sites. We examined 15 ADCs with PBD-dimer payloads and a DAR of 2 and concluded that dose limiting toxicities in animals and in humans are generally related to the payload. Both the payloads and the ADCs had pro-inflammatory responses causing severe toxicities that were at times of low incidence, making it difficult to assess a cause-effect relationship. Due to their low incidence, single-patient cohorts may not detect these events and such design may not be suitable in first-in-human (FIH) trials. The commonly proposed approach by the sponsors for FIH dose selection was 1/6th highest non-severely toxic dose (HNSTD) in monkeys. This approach resulted in an acceptable balance of safety and efficient dose escalation in phase 1 trials, when using data from repeat-dose toxicology studies and body surface area for scaling. No sponsor used the data generated in rodents or proposed novel approaches for FIH dose selection.

Concurrent Use of Benzodiazepine by Heroin Users-What Are the Prevalence and the Risks Associated with This Pattern of Use?

INTRODUCTION: Polydrug use involving heroin and benzodiazepines is common. The potential risk of additive pharmacological effects may be associated with poorer outcomes in patients who use benzodiazepines together with heroin. The aim of this study was to determine the clinical picture of patients presenting to the emergency department following acute drug toxicity involving heroin and benzodiazepines. METHODS: Exposure information, clinical data and outcome of acute drug toxicity presentations were collected between 1 October 2013 and 30 September 2014 as part of the European Drug Emergencies Network (Euro-DEN) project. The database was interrogated to identify patients who had taken heroin with or without benzodiazepine(s). RESULTS: A total of 1345 presentations involving acute heroin toxicity were identified: 492 had used one or more non-heroin/benzodiazepine drug and were not further considered in this study; 662 were lone heroin users and 191 had co-used heroin with one or more benzodiazepines. Co-users were more likely than lone heroin users to have reduced respiratory rate at presentation 12.7 ± 4.9 vs 13.6 ± 4.4 (p = 0.02) and require admission to hospital 18.3 vs 9.8% (p < 0.01). There were no differences in critical care admission rates 3.1 vs 3.9% (p = 0.83) or length of stay 4 h 59 min vs 5 h 32 min (p = 0.23). The 3 most common benzodiazepines were clonazepam, diazepam, and alprazolam. No differences were observed for clinical features between the three benzodiazepines. CONCLUSION: This study shows that co-use of heroin and benzodiazepines is common, although the overall outcomes between co-users of heroin and benzodiazepines and heroin-only users were similar.

Evaluation of Pyrrolobenzodiazepine-Loaded Nanoparticles: A Targeted Drug Delivery Approach.

We describe the development and evaluation of pyrrolobenzodiazepines (PBDs) in poly(dl-lactide-co-glycolide) and lipid nanoparticle drug delivery systems. We have established that the partition coefficient (LogP) of PBD is a key influencer of the encapsulation efficiency in nanoparticle systems, with higher LogP values associated with higher encapsulation efficiencies toward increased drug payload delivery and better antitumor efficacy. Cytotoxicity assays demonstrated that compounds with higher LogP values demonstrated higher 50% inhibitory concentration values than the free drug. In vivo efficacy studies in mice demonstrated that a single injection of nanoparticle PBD formulations could inhibit tumor growth for nearly 3 weeks, whereas the free drug failed to inhibit growth. Importantly, mice treated with PBD-loaded nanoparticles did not experience significant loss of body weight. These data demonstrate that nanoparticles containing PBD molecules can be used as an alternative to the widely used antibody drug conjugate approach in delivering cytotoxic PBDs.

Development of pyrrolo[2,1-c][1,4]benzodiazepine ß-glucoside prodrugs for selective therapy of cancer.

Cancer chemotherapy has several limitations such as often insufficient differentiation between malign tissue and benign tissue. The clinical utility of the pyrrolo[2,1-c][1,4]benzodiazepines (PBDs) are inadequate because of the lack of selectivity for tumor tissues, high reactivity of the pharmacophoric imine functionality, low water solubility, and stability. To address these limitations two new ß-glucoside prodrugs of PBDs have been synthesized and evaluated for their potential use in selective therapy of solid tumors by ADEPT. The preliminary studies reveal the prodrugs are much less toxic compared to the parent moieties. These prodrugs are activated by ß-glucosidase to produce the active cytotoxic moiety signifying their utility in ADEPT of cancer. The prodrugs 1a and 1b were evaluated for their cytotoxic activity in three human cancer cell lines, i.e., A375, MCF-7 and HT-29 by employing MTT assay. The results reveal that the prodrugs have shown significant cytotoxic activity in the presence of enzyme. Another important property of these molecules is their enhanced water solubility and stability, which are essential for a molecule to be an effective drug.

Olanzapine-induced early cardiovascular effects are mediated by the biological clock and prevented by melatonin.

Second generation antipsychotics (SGA) are associated with adverse cardiometabolic side effects contributing to premature mortality in patients. While mechanisms mediating these cardiometabolic side effects remain poorly understood, three independent studies recently demonstrated that melatonin was protective against cardiometabolic risk in SGA-treated patients. As one of the main target areas of circulating melatonin in the brain is the suprachiasmatic nucleus (SCN), we hypothesized that the SCN is involved in SGA-induced early cardiovascular effects in Wistar rats. We evaluated the acute effects of olanzapine and melatonin in the biological clock, paraventricular nucleus and autonomic nervous system using immunohistochemistry, invasive cardiovascular measurements, and Western blot. Olanzapine induced c-Fos immunoreactivity in the SCN followed by the paraventricular nucleus and dorsal motor nucleus of the vagus indicating a potent induction of parasympathetic tone. The involvement of a SCN-parasympathetic neuronal pathway after olanzapine administration was further documented using cholera toxin-B retrograde tracing and vasoactive intestinal peptide immunohistochemistry. Olanzapine-induced decrease in blood pressure and heart rate confirmed this. Melatonin abolished olanzapine-induced SCN c-Fos immunoreactivity, including the parasympathetic pathway and cardiovascular effects while brain areas associated with olanzapine beneficial effects including the striatum, ventral tegmental area, and nucleus accumbens remained activated. In the SCN, olanzapine phosphorylated the GSK-3ß, a regulator of clock activity, which melatonin prevented. Bilateral lesions of the SCN prevented the effects of olanzapine on parasympathetic activity. Collectively, results demonstrate the SCN as a key region mediating the early effects of olanzapine on cardiovascular function and show melatonin has opposing and potentially protective effects warranting additional investigation.

El Diazepam altera la ultraestructura del atrio fetal de ratón / Diazepam alters the ultrastructure of fetal atrium in rat

El diazepam (DZ) es un tranquilizante menor sintético, utilizado en pacientes con trastornos psicológicos y psiquiátricos. Es sedante, miorrelajante, anticonvulsionante y antipsicótico. El DZ atraviesa la barrera placentaria humana y la del ratón. Mujeres jóvenes que son adictas al fármaco, si se embarazan y continúan utilizándolo, sobre todo durante el primer trimestre, exponen a sus hijos a presentar alteraciones psicomotoras. El propósito de este trabajo fue investigar si el DZ administrado durante la gestación,induce alteraciones ultraestructurales del miocardio fetal de ratón. El grupo (DZ) de hembras gestantes deratón de la cepa CD-1 fue tratado con dosis únicas diarias de 1,0 mg/kg/pc/sc del día 6 al 17 y un grupo (C)que recibió solución salina. El día 18 las hembras de ambos grupos se anestesiaron, los fetos se perfundieron por vía intracardiaca con paraformaldehído al 1 % y glutaraldehido al 2,5 %, se les extrajo el corazón, se disecó el atrio, se fijó en OsO4 al 1 % y se incluyó en resina epóxica. Los cortes finos se contrastaron conacetato de uranilo y citrato de plomo y se observaron en un microscopio electrónico de transmisión. En los miocitos de los fetos del grupo DZ las sarcómeras del miocardio compacto tenían menor longitud que las del grupo C. Se observaron zonas con miofibrillas desorganizadas. El retículo sarcoplásmico de algunos miocitos presentaba cisternas distendidas y fragmentadas, mitocondrias alteradas y se observaron abundantes polirribosomas. Los cambios podrían deberse al efecto del DZ sobre la síntesis de actina y miosina pesada y sobre los organelos citoplásmicos, mediados por receptores benzodiazepínicos periféricos presentes en la membrana externa de las mitocondrias y asociados a canales de calcio dependientes de voltaje. Las alteraciones ultraestructurales del miocardio atrial de fetos de ratones expuestos in utero a DZ podrían tener efectos posnatales.

Diazepam (DZ) is a syntheticminor tranquilizer, used in patients with psychologicaland psychiatric disorders. It is a relaxing sedative,anticonvulsant and antipsychotic. DZ crosses thehuman placental barrier in mouse. Young women who are addicted to the drug, if they become pregnantand continue to use it, particularly during the firsttrimester, expose their children to psychomotor disorders. The purpose of this study was to investigate whether DZ administered during pregnancy induces ultrastructural alterations of fetal mouse myocardium.The group (DZ) of pregnant female mice of the CD-1strain was treated with a single daily dose of 1.0 mg/ kg / pc / sc of day 6 to 17 and a group (C) that received saline solution. On day 18 females of bothgroups were anesthetized, the fetuses were perfusedby intracardiac route with 1 % paraformaldehyde and 2.5 % glutaraldehyde, the heart was removed, theatrium was dissected, fixed in 1 % OsO4, it wasimmersed in epoxy resin. The fine sections werecontrasted with uranyl acetate and lead citrate and observed in a transmission electron microscope. Inthe myocytes of the fetuses of the DZ group, the sarcomers of the compact myocardium were shorter than those of the C group. Areas with disorganized myofibrils were observed. The sarcoplasmic reticulumof some myocytes had distended and fragmented 996cisterns, altered mitochondria, and abundant polyribosomes were observed. The changes may bedue to the effect of DZ on the synthesis of actin and heavy myosin and on cytoplasmic organelles mediatedby peripheral benzodiazepine receptors present onthe outer membrane of the mitochondria and associated with voltage-dependent calcium channels.Ultrastructural alterations of the atrial myocardium of fetuses of mice exposed to DZ in utero may have postnatal effects.

Frequência de medicamentos potencialmente inapropriados em pacientes internados com delirium / Frequency of potentially inappropriate drugs in hospitalized patients with delirium

OBJETIVO: Delirium é uma condição frequente em idosos com doenças agudas, associado à alta morbimortalidade e ao prolongamento do período de internação. Diversos fármacos estão relacionados ao risco de desencadeá-lo ou agravá-lo. O objetivo do estudo foi identificar medicamentos potencialmente causadores de delirium em pacientes idosos portadores desta síndrome e seu risco para mortalidade durante a hospitalização. MÉTODOS: Realizou-se estudo transversal, com 51 idosos internados que preenchiam critérios de diagnóstico para delirium pelo Confusion Assesment Method. Os fármacos potencialmente inapropriados foram os relacionados segundos os critérios de Beers. As variáveis avaliadas foram: idade, gênero, causas do delirium, fármacos em uso regular, período de internação e óbitos. RESULTADOS: 30 pacientes (58,82%) faziam uso de fármacos de risco para delirium, sendo que 39,2% utilizavam medicamentos considerados de alto risco e 13,7% usavam concomitantemente três fármacos. Dentre as medicações de alto risco, os benzodiazepínicos foram empregados em 23,5% dos pacientes. O tempo médio de internação foi de 24±18 (1-86) dias e 25 (49%) pacientes evoluíram para o óbito. CONCLUSÃO:Observou-se longa permanência hospitalar e frequente uso de medicamentos com potencial de agravar ou desencadear o estado de delirium, sendo os benzodiazepínicos, os mais frequentemente utilizados. Apesar da alta mortalidade, não foi possível associar este fato ao uso dos fármacos. Tais resultados ratificam que o delirium é uma síndrome pouco reconhecida pelos clínicos em um hospital geral.

OBJECTIVE: The aim of the study was to identify the medications potentially causing or exacerbating delirium in elderly patients, and review the risk of mortality associated with the use of these medications during hospitalization. METHODS: Cross-sectional study with 51 elderly inpatients who met diagnostic criteria for delirium. The pharmaceuticals considered inappropriate were related according to the Beers criteria. The variables were: age, gender, cause for delirium, pharmaceuticals in regular use, hospitalization time and deaths. RESULTS: 30 patients (58,82%) were using pharmaceuticals that presented a risk of delirium. 39.2% of these used medications of high risk, 23.5% being benzodiazepines. 25 (49%) patients died during hospitalization. CONCLUSION: It was noted frequent use of potentially inappropriate drugs, benzodiazepines being the most frequently used. However, this fact was not linked to the high mortality. These results confirm that delirium is a syndrome that is poorly recognized by clinicians in a general hospital.

Cardiovascular effects of acute treatment with the antipsychotic drug olanzapine in rats.

Treatment with antipsychotics is associated with adverse cardiovascular effects such as orthostatic hypotension and arrhythmias. Despite the higher prevalence of cardiovascular complications in patients with schizophrenia, the effects of antipsychotic drugs on vascular tone and cardiac contractility have received little attention. In order to better understand the cardiovascular effects of antipsychotic drugs, we investigated if the atypical antipsychotic olanzapine alters in vivo cardiovascular function in rats. Male Sprague-Dawley rats were prepared with indwelling catheters. After 4 h of recovery from surgery, the mean arterial pressure (MAP), mean circulatory filling pressure (MCFP; index of body venous tone), heart rate, left ventricular peak systolic pressure (LVP) and cardiac contractility (±dP/dt) were measured in conscious, unrestrained rats for 60 min after a single injection of olanzapine (3 or 15 mg/kg, i.p.) or vehicle. Cardiovascular measurements were not altered at any time points in the vehicle-treated rats. Olanzapine did not affect heart rate, but dose-dependently decreased MAP, MCFP, LVP and +dP/dt. Acute olanzapine treatment in rats thus reduced blood pressure and venous tone, as well as cardiac contractile function. Decreased venous tone may be a contributing factor to orthostatic hypotension commonly observed in patients during initiation of antipsychotic therapy.

Olanzapine-induced hyperglycemia: possible involvement of histaminergic, dopaminergic and adrenergic functions in the central nervous system.

BACKGROUND/AIMS: Atypical antipsychotic drugs such as olanzapine are known to induce metabolic disturbance. We have already shown that olanzapine induces hepatic glucose production through the activation of hypothalamic adenosine 5'-monophosphate-activated protein kinase (AMPK). However, it is unclear how olanzapine activates hypothalamic AMPK. Since olanzapine is known to antagonize several receptors, including histaminergic, muscarinic, serotonergic, dopaminergic and adrenergic receptors, we examined the effect of each receptor antagonist on blood glucose levels in mice. Moreover, we also investigated whether these antagonists activate hypothalamic AMPK. METHODS: Male 6-week-old ICR mice were used. Blood glucose levels were determined by the glucose oxidase method. AMPK expression was measured by Western blotting. RESULTS: Central administration of olanzapine (5-15 nmol i.c.v.) dose-dependently increased blood glucose levels in mice, whereas olanzapine did not change blood insulin levels. Histamine H1 receptor antagonist chlorpheniramine (1-10 µg i.c.v.), dopamine D2 receptor antagonist L-sulpiride (1-10 µg i.c.v.) and α1-adrenoceptor antagonist prazosin (0.3-3 µg i.c.v.) also significantly increased blood glucose levels in mice. In contrast, the blood glucose levels were not affected by muscarinic M1 receptor antagonist dicyclomine (1-10 µg i.c.v.) or serotonin 5-HT2A receptor antagonist M100907 (1-10 ng i.c.v.). Olanzapine-induced hyperglycemia was inhibited by the AMPK inhibitor compound C, and AMPK activator AICAR (10 ng to 1 µg i.c.v.) significantly increased blood glucose levels. Olanzapine (15 nmol), chlorpheniramine (10 µg), L-sulpiride (10 µg) and prazosin (3 µg) significantly increased phosphorylated AMPK in the hypothalamus of mice. CONCLUSION: These results suggest that olanzapine activates hypothalamic AMPK by antagonizing histamine H1 receptors, dopamine D2 receptors and α1-adrenoceptors, which induces hyperglycemia.

BET inhibition silences expression of MYCN and BCL2 and induces cytotoxicity in neuroblastoma tumor models.

BET family proteins are epigenetic regulators known to control expression of genes involved in cell growth and oncogenesis. Selective inhibitors of BET proteins exhibit potent anti-proliferative activity in a number of hematologic cancer models, in part through suppression of the MYC oncogene and downstream Myc-driven pathways. However, little is currently known about the activity of BET inhibitors in solid tumor models, and whether down-regulation of MYC family genes contributes to sensitivity. Here we provide evidence for potent BET inhibitor activity in neuroblastoma, a pediatric solid tumor associated with a high frequency of MYCN amplifications. We treated a panel of neuroblastoma cell lines with a novel small molecule inhibitor of BET proteins, GSK1324726A (I-BET726), and observed potent growth inhibition and cytotoxicity in most cell lines irrespective of MYCN copy number or expression level. Gene expression analyses in neuroblastoma cell lines suggest a role of BET inhibition in apoptosis, signaling, and N-Myc-driven pathways, including the direct suppression of BCL2 and MYCN. Reversal of MYCN or BCL2 suppression reduces the potency of I-BET726-induced cytotoxicity in a cell line-specific manner; however, neither factor fully accounts for I-BET726 sensitivity. Oral administration of I-BET726 to mouse xenograft models of human neuroblastoma results in tumor growth inhibition and down-regulation MYCN and BCL2 expression, suggesting a potential role for these genes in tumor growth. Taken together, our data highlight the potential of BET inhibitors as novel therapeutics for neuroblastoma, and suggest that sensitivity is driven by pleiotropic effects on cell growth and apoptotic pathways in a context-specific manner.

An acute rat in vivo screening model to predict compounds that alter blood glucose and/or insulin regulation.

INTRODUCTION: Drug-induced glucose dysregulation and insulin resistance have been associated with weight gain and potential induction and/or exacerbation of diabetes mellitus in the clinic suggesting they may be safety biomarkers when developing antipsychotics. Glucose and insulin have also been suggested as potential efficacy biomarkers for some oncology compounds. The objective of this study was to qualify a medium throughput rat in vivo acute Intravenous Glucose Tolerance Test (IVGTT) for predicting compounds that will induce altered blood glucose and/or insulin levels. METHODS: Acute and sub-chronic studies were performed to qualify an acute IVGTT model. Double cannulated male rats (Han-Wistar and Sprague-Dawley) were administered vehicle, olanzapine, aripiprazole or other compounds at t=-44min for acute studies and at time=-44min on the last day of dosing for sub-chronic studies, treated with dextrose (time=0min; i.v.) and blood collected using an automated Culex® system for glucose and insulin analysis (time=-45, -1, 2, 10, 15, 30, 45, 60, 75, 90, 120, 150 and 180min). RESULTS: Olanzapine significantly increased glucose and insulin area under the curve (AUC) values while aripiprazole AUC values were similar to control, in both acute and sub-chronic studies. All atypical antipsychotics evaluated were consistent with literature references of clinical weight gain. As efficacy biomarkers, insulin AUC but not glucose AUC values were increased with a compound known to have insulin growth factor-1 (IGF-1) activity, compared to control treatment. DISCUSSION: These studies qualified the medium throughput acute IVGTT model to more quickly screen compounds for 1) safety - the potential to elicit glucose dysregulation and/or insulin resistance and 2) efficacy - as a surrogate for compounds affecting the glucose and/or insulin regulatory pathways. These data demonstrate that the same in vivo rat model and assays can be used to predict both clinical safety and efficacy of compounds.

Mouse precision-cut liver slices as an ex vivo model to study idiosyncratic drug-induced liver injury.

Idiosyncratic drug-induced liver injury (IDILI) has been the top reason for withdrawing drugs from the market or for black box warnings. IDILI may arise from the interaction of a drug's reactive metabolite with a mild inflammation that renders the liver more sensitive to injury resulting in increased toxicity (inflammatory stress hypothesis). Aiming to develop a robust ex vivo screening method to study inflammatory stress-related IDILI mechanisms and to find biomarkers that can detect or predict IDILI, mouse precision-cut liver slices (mPCLS) were coincubated for 24 h with IDILI-related drugs and lipopolysaccharide. Lipopolysaccharide exacerbated ketoconazole (15 µM) and clozapine (45 µM) toxicity but not their non-IDILI-related comparators, voriconazole (1500 µM) and olanzapine (45 µM). However, the other IDILI-related drugs tested [diclofenac (200 µM), carbamazepine (400 µM), and troglitazone (30 µM)] did not cause synergistic toxicity with lipopolysaccharide after 24 h of incubation. Lipopolysaccharide further decreased the reduced glutathione levels caused by ketoconazole or clozapine in mPCLS after 24 h of incubation, which was not the case for the other drugs. Lipopolysaccharide significantly increased nitric oxide (NO), cytokine, and chemokine release into the mPCLS media, while the treatment with the drugs alone did not cause any substantial change. All seven drugs drastically reduced lipopolysaccharide-induced NO production. Interestingly, only ketoconazole and clozapine increased the lipopolysaccharide-induced granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) release. Pilot experiments showed that diclofenac and troglitazone, but not carbamazepine, demonstrated synergistic toxicity with lipopolysaccharide after a longer incubation of 48 h in mPCLS. In conclusion, we have developed an ex vivo model to detect inflammatory stress-related liver toxicity and identified ketoconazole, clozapine, troglitazone, and diclofenac as drugs that showed synergistic toxicity with lipopolysaccharide. Reduced glutathione, G-CSF, and GM-CSF were identified to be potential biomarkers for IDILI-inducing drugs mediated by inflammatory stress, and mPCLS appear to be a promising screening tool to further unravel the mechanism of IDILI.

Synthesis and cytotoxicity testing of new amido-substituted triazolopyrrolo[2,1-c][1,4]benzodiazepine (PBDT) derivatives.

A series of amido-substituted triazolopyrrolo[2,1-c][1,4]benzodiazepine (PBDT) derivatives was synthesized from isatoic anhydride, and their cytotoxicity against the MRC-5 and Mahlavu cell lines was evaluated. The results suggest that compound PBDT-7i with the meta-trifluoromethylbenzoyl substituent can selectively inhibit the growth of Mahlavu cells and has low toxicity towards MRC-5 cells.

Atypical antipsychotics rapidly and inappropriately switch peripheral fuel utilization to lipids, impairing metabolic flexibility in rodents.

Patients taking atypical antipsychotics are frequented by serious metabolic (eg, hyperglycemia, obesity, and diabetes) and cardiac effects. Surprisingly, chronic treatment also appears to lower free fatty acids (FFAs). This finding is paradoxical because insulin resistance is typically associated with elevated not lower FFAs. How atypical antipsychotics bring about these converse changes in plasma glucose and FFAs is unknown. Chronic treatment with olanzapine, a prototypical, side effect prone atypical antipsychotic, lowered FFA in Sprague-Dawley rats. Olanzapine also lowered plasma FFA acutely, concomitantly impairing in vivo lipolysis and robustly elevating whole-body lipid oxidation. Increased lipid oxidation was evident from accelerated losses of triglycerides after food deprivation or lipid challenge, elevated FFA uptake into most peripheral tissues (∼2-fold) except heart, rises in long-chain 3-hydroxylated acyl-carnitines observed in diabetes, and rapid suppression of the respiratory exchange ratio (RER) during the dark cycle. Normal rises in RER following refeeding, a sign of metabolic flexibility, were severely blunted by olanzapine. Increased lipid oxidation in muscle could be explained by ∼50% lower concentrations of the negative cytoplasmic regulator of carnitine palmitoyltransferase I, malonyl-CoA. This was associated with loss of anapleurotic metabolites and citric acid cycle precursors of malonyl-CoA synthesis rather than adenosine monophosphate-activated kinase activation or direct ACC1/2 inhibition. The ability of antipsychotics to lower dark cycle RER in mice corresponded to their propensities to cause metabolic side effects. Our studies indicate that lipocentric mechanisms or altered intermediary metabolism could underlie the FFA lowering and hyperglycemia (Randle cycle) as well as some of the other side effects of atypical antipsychotics, thereby suggesting strategies for alleviating them.

The new low-toxic histone deacetylase inhibitor S-(2) induces apoptosis in various acute myeloid leukaemia cells.

Histone deacetylase inhibitors (HDACi) induce tumour cell cycle arrest and/or apoptosis, and some of them are currently used in cancer therapy. Recently, we described a series of powerful HDACi characterized by a 1,4-benzodiazepine (BDZ) ring hybridized with a linear alkyl chain bearing a hydroxamate function as Zn(++)--chelating group. Here, we explored the anti-leukaemic properties of three novel hybrids, namely the chiral compounds (S)-2 and (R)-2, and their non-chiral analogue 4, which were first comparatively tested in promyelocytic NB4 cells. (S)-2 and partially 4--but not (R)-2--caused G0/G1 cell-cycle arrest by up-regulating cyclin G2 and p21 expression and down-regulating cyclin D2 expression, and also apoptosis as assessed by cell morphology and cytofluorimetric assay, histone H2AX phosphorylation and PARP cleavage. Notably, these events were partly prevented by an anti-oxidant. Moreover, novel HDACi prompted p53 and α-tubulin acetylation and, consistently, inhibited HDAC1 and 6 activity. The rank order of potency was (S)-2 > 4 > (R)-2, reflecting that of other biological assays and addressing (S)-2 as the most effective compound capable of triggering apoptosis in various acute myeloid leukaemia (AML) cell lines and blasts from patients with different AML subtypes. Importantly, (S)-2 was safe in mice (up to 150 mg/kg/week) as determined by liver, spleen, kidney and bone marrow histopathology; and displayed negligible affinity for peripheral/central BDZ-receptors. Overall, the BDZ-hydroxamate (S)-2 showed to be a low-toxic HDACi with powerful anti-proliferative and pro-apototic activities towards different cultured and primary AML cells, and therefore of clinical interest to support conventional anti-leukaemic therapy.