Chronic administration of fluoxetine or clozapine induces oxidative stress in rat liver: a histopathological study

Involvement of Extracellular Vesicles in the Proinflammatory Response to Clozapine: Implications for Clozapine-Induced Agranulocytosis

Most idiosyncratic drug reactions (IDRs) appear to be immune-mediated, but mechanistic events preceding severe reaction onset remain poorly defined. Damage-associated molecular patterns (DAMPs) may contribute to both innate and adaptive immune phases of IDRs, and changes in extracellular vesicle (EV) cargo have been detected post-exposure to several IDR-associated drugs. To explore the hypothesis that EVs are also a source of DAMPs in the induction of the immune response preceding drug-induced agranulocytosis, the proteome and immunogenicity of clozapine- (agranulocytosis-associated drug) and olanzapine- (non-agranulocytosis-associated drug) exposed EVs were compared in two preclinical models: THP-1 macrophages and Sprague-Dawley rats. Compared with olanzapine, clozapine induced a greater increase in the concentration of EVs enriched from both cell culture media and rat serum. Moreover, treatment of drug-naïve THP-1 cells with clozapine-exposed EVs induced an inflammasome-dependent response, supporting a potential role for EVs in immune activation. Proteomic and bioinformatic analyses demonstrated an increased number of differentially expressed proteins with clozapine that were enriched in pathways related to inflammation, myeloid cell chemotaxis, wounding, transforming growth factor-β signaling, and negative regulation of stimuli response. These data indicate that, although clozapine and olanzapine exposure both alter the protein cargo of EVs, clozapine-exposed EVs carry mediators that exhibit significantly greater immunogenicity. Ultimately, this supports the working hypothesis that drugs associated with a risk of IDRs induce cell stress, release of proinflammatory mediators, and early immune activation that precedes severe reaction onset. Further studies characterizing EVs may elucidate biomarkers that predict IDR risk during development of drug candidates. SIGNIFICANCE STATEMENT: This work demonstrates that clozapine, an idiosyncratic drug-induced agranulocytosis (IDIAG)-associated drug, but not olanzapine, a safer structural analogue, induces an acute proinflammatory response and increases extracellular vesicle (EV) release in two preclinical models. Moreover, clozapine-exposed EVs are more immunogenic, as measured by their ability to activate inflammasomes, and contain more differentially expressed proteins, highlighting a novel role for EVs during the early immune response to clozapine and enhancing our mechanistic understanding of IDIAG and other idiosyncratic reactions.

Antifungal activity of selective serotonin reuptake inhibitors against Cryptococcus spp. and their possible mechanism of action

Fungal infections caused by Cryptococcus spp. pose a threat to health, especially in immunocompromised individuals. The available arsenal of drugs against cryptococcosis is limited, due to their toxicity and/or lack of accessibility in low-income countries, requiring more therapeutic alternatives. Selective serotonin reuptake inhibitors (SSRIs), through drug repositioning, are a promising alternative to broaden the range of new antifungals against Cryptococcus spp. This study evaluates the antifungal activity of three SSRIs, sertraline, paroxetine, and fluoxetine, against Cryptococcus spp. strains, as well as assesses their possible mechanism of action. Seven strains of Cryptococcus spp. were used. Sensitivity to SSRIs, fluconazole, and itraconazole was evaluated using the broth microdilution assay. The interactions resulting from combinations of SSRIs and azoles were investigated using the checkerboard assay. The possible action mechanism of SSRIs against Cryptococcus spp. was evaluated through flow cytometry assays. The SSRIs exhibited in vitro antifungal activity against Cryptococcus spp. strains, with minimum inhibitory concentrations ranging from 2 to 32 μg/mL, and had synergistic and additive interactions with azoles. The mechanism of action of SSRIs against Cryptococcus spp. involved damage to the mitochondrial membrane and increasing the production of reactive oxygen species, resulting in loss of cellular viability and apoptotic cell death. Fluoxetine also was able to cause significant damage to yeast DNA. These findings demonstrate the in vitro antifungal potential of SSRIs against Cryptococcus spp. strains.

The Possible Ameliorating Role of Fisetin on Hepatic Changes Induced by Fluoxetine in Adult Male Albino Rats: Histological, Immunohistochemical, and Biochemical Study

Background

Fluoxetine (FLX) is one of the selective serotonin reuptake inhibitors, it is widely used to treat neuropsychiatric disorders including depression, but high doses can cause several adverse effects. Fisetin (FIS), a bioactive flavonoid presents in vegetables and fruits, has antioxidant, anti-inflammatory, and anticancer effects.

Aim

To evaluate the possible ameliorating effect of FIS on the hepatic alterations induced by FLX in adult male albino rats.

Materials and Methods

Our study was done, for 3-weeks, on 48 rats that were divided into four groups: Group I (control), Group II received FIS orally (100 mg/kg/day), Group III received FLX orally (10 mg/kg/day), and Group IV concomitantly received FLX and FIS at the same dose and manner of groups II and III. Blood and liver samples were obtained and prepared for histological, immunohistochemical, and biochemical studies.

Results

FLX group revealed disturbed liver architecture, hepatocytes with vacuolated cytoplasm, inflammatory cellular infiltration, blood extravasation, and congestion of blood vessels in addition to, a significant increase in the area percentage of caspase-3, inducible nitric oxide synthase and the number of glial fibrillary acidic protein-expressing cells as well as a significant decrease in the area percentage of periodic acid-Schiff stain. Moreover, FLX significantly increased aspartate-aminotransferase and alanine-aminotransferase levels in the serum. In addition, FLX increased malondialdehyde level and decreased superoxide dismutase, glutathione (GSH) peroxidase, and reduced GSH levels in liver tissue. The concomitant administration of FIS ameliorated these alterations.

Conclusions

Administration of FIS ameliorated the histological, immunohistochemical, and biochemical alterations induced by FLX in the liver of adult male albino rats.

Stress, a Brief Update

Stress is fundamental for health and adaptation; it is an evolutionarily conserved response that involves several systems in the organism. The study of the stress response could be traced back to the end of the nineteenth century with George Beard's or Claude Bernard's work and, from that moment on, several studies that have allowed the elucidation of its neurobiology and the consequences of suffering from it were consolidated. In this theoretical review, we discuss the most relevant researches to our knowledge on the study of stress response, from the concept of stress, its neurobiology, the hormonal response during stress, as well as its regulation, the effects of acute and chronic stress, stress from cognition, the different stress responses during life, as well as its relationship with different psychiatric disorders. Taken together, the reviewed research updates the classic perspective on stress, increasing the factors that should be considered in research to explore the effects of stress on health.

Clozapine Suppresses the Gene Expression and the Production of Cytokines and Up-Regulates Cyclooxygenase 2 mRNA in Human Astroglial Cells

Schizophrenia (SCZ) is a chronic neurodevelopmental psychotic disorder. The immune system and neuroinflammation seem to play a central role in the pathophysiology of SCZ. Clozapine is an effective atypical antipsychotic used for treatment-resistant SCZ. Life-threatening side effects, such as myocarditis, limit its use. We investigated the immunomodulatory effects of clozapine in an astroglial model of neuroinflammation. We thus assessed the effect of clozapine on the production of inflammatory mediators in human-derived astroglial (A172) cells, stimulated with a cytokine mix (TNFα, IL-1β, IFNγ). RT-PCR and ELISA analyses demonstrated that clozapine suppressed gene expression and production of TNFα, IL-1β and IL-8 and increased COX2 mRNA 24 h after stimulation. Clozapine inhibited Akt phosphorylation induced by the cytokine mix at 10 min and 40 min, as assessed by Western blot analysis with anti-pT308Akt antibody. Pretreatment with the Akt inhibitor MK-2206 increased COX2 gene expression in cytokine-stimulated cells, suggesting that Akt inhibition may be involved in COX2 gene expression upregulation. Clozapine may possess dual beneficial effects: inhibiting astroglial production of proinflammatory cytokines, thus attenuating neuroinflammation, and upregulating COX2 expression that may be relevant to improvement of neural functioning while accounting for some of its detrimental effects. Patients with TRS and neuroinflammatory markers may benefit particularly from clozapine treatment.

Mechanism-driven modeling of chemical hepatotoxicity using structural alerts and an in vitro screening assay

Traditional experimental approaches to evaluate hepatotoxicity are expensive and time-consuming. As an advanced framework of risk assessment, adverse outcome pathways (AOPs) describe the sequence of molecular and cellular events underlying chemical toxicities. We aimed to develop an AOP that can be used to predict hepatotoxicity by leveraging computational modeling and in vitro assays. We curated 869 compounds with known hepatotoxicity classifications as a modeling set and extracted assay data from PubChem. The antioxidant response element (ARE) assay, which quantifies transcriptional responses to oxidative stress, showed a high correlation to hepatotoxicity (PPV=0.82). Next, we developed quantitative structure-activity relationship (QSAR) models to predict ARE activation for compounds lacking testing results. Potential toxicity alerts were identified and used to construct a mechanistic hepatotoxicity model. For experimental validation, 16 compounds in the modeling set and 12 new compounds were selected and tested using an in-house ARE-luciferase assay in HepG2-C8 cells. The mechanistic model showed good hepatotoxicity predictivity (accuracy = 0.82) for these compounds. Potential false positive hepatotoxicity predictions by only using ARE results can be corrected by incorporating structural alerts and vice versa. This mechanistic model illustrates a potential toxicity pathway for hepatotoxicity, and this strategy can be expanded to develop predictive models for other complex toxicities.

The role of NLRP3 inflammasome in psychotropic drug-induced hepatotoxicity

Increased medical application of psychotropic drugs raised attention concerning their toxicological effects. In fact, more than 160 psychotropic drugs including antidepressants and antipsychotics, have been shown to cause liver side effects, but the underlying mechanisms are still poorly understood. Here, we discovered that fluoxetine, a common antidepressant, was specifically sensed by NLRP3 inflammasome, whose subsequent activation resulted in the maturation of caspase-1 and IL-1β, as well as gasdermin D (GSDMD) cleavage, which could be completely abrogated by a selective NLRP3 inhibitor MCC950 or Nlrp3 knockout (Nlrp3^−/−). Mechanistically, mitochondrial damage and the subsequent mitochondrial reactive oxygen species (mtROS) accumulation were crucial upstream signaling events in fluoxetine-triggered NLRP3 inflammasome activation. In fluoxetine hepatotoxicity models, mice showed the alterations of aminotransferase levels, hepatic inflammation and hepatocyte death in an NLRP3-dependent manner, and MCC950 pretreatment could reverse these side effects of fluoxetine. Notably, we also found that multiple antidepressants, such as amitriptyline, paroxetine, and imipramine, and antipsychotics, such as asenapine, could specifically trigger the NLRP3 inflammasome activation. Collectively, our findings implicate multiple psychotropic drugs may act as danger signals sensed by the NLRP3 inflammasome and result in hepatic injury.

Protective role of ellagic acid and taurine against fluoxetine induced hepatotoxic effects on biochemical and oxidative stress parameters, histopathological changes, and gene expressions of IL-1β, NF-κB, and TNF-α in male Wistar rats

PURPOSES

Hepatic bioactivation of fluoxetine (FXN) could increase free radicals' generation provoking hepatotoxicity. Therefore, the protective effects of ellagic acid (EA) and taurine (TAU) treatments against fluoxetine-induced liver damage in rats were examined.

MATERIALS AND METHODS

Sixty four male Wistar rats were randomly assigned to 8 groups (n = 8). Group (1) Control, group (2) FXN, group (3) FXN + EA, group (4) FXN + TAU, group (5) FXN + EA + TAU, group (6) EA, group (7) TAU, and group (8) EA + TAU. Then, the serum and tissue parameters of the oxidative stress were examined.

KEY FINDINGS

FXN significantly raised serum MDA, protein carbonyl, lipid profile, ALT, AST, ALP, total bilirubin, serum IL-1β; and gene expressions of IL-1β, NF-κB, and TNF-α. Moreover, it significantly decreased HDL-C, ferric reducing antioxidant power (FRAP), catalase activity, vitamin C, and SOD activity in the liver compared to group 1. When compared to group 2, EA and TAU treatment dramatically increased antioxidant capacity and lowered hepatotoxic biochemical markers and cellular inflammation. Results also showed a protective effect of treatment against oxidative damage caused by hepatocytes' cytoarchitecture.

SIGNIFICANCE

Our study concluded the beneficial effects of EA and TAU on FXN-induced hepatotoxicity. These effects were derived from free radical scavenging properties and the anti-inflammatory effects related to IL-1β, NF-κB, and TNF-α gene expression inhibition.

Oxidative Stress, Genomic Integrity, and Liver Diseases

Excess reactive oxygen species production and free radical formation can lead to oxidative stress that can damage cells, tissues, and organs. Cellular oxidative stress is defined as the imbalance between ROS production and antioxidants. This imbalance can lead to malfunction or structure modification of major cellular molecules such as lipids, proteins, and DNAs. During oxidative stress conditions, DNA and protein structure modifications can lead to various diseases. Various antioxidant-specific gene expression and signal transduction pathways are activated during oxidative stress to maintain homeostasis and to protect organs from oxidative injury and damage. The liver is more vulnerable to oxidative conditions than other organs. Antioxidants, antioxidant-specific enzymes, and the regulation of the antioxidant responsive element (ARE) genes can act against chronic oxidative stress in the liver. ARE-mediated genes can act as the target site for averting/preventing liver diseases caused by oxidative stress. Identification of these ARE genes as markers will enable the early detection of liver diseases caused by oxidative conditions and help develop new therapeutic interventions. This literature review is focused on antioxidant-specific gene expression upon oxidative stress, the factors responsible for hepatic oxidative stress, liver response to redox signaling, oxidative stress and redox signaling in various liver diseases, and future aspects.

Haloperidol alters the behavioral, hematological and biochemical parameters of freshwater African catfish, Clarias gariepinus (Burchell 1822)

The presence of drugs and their metabolites in surface waters and municipal effluents has been reported in several studies, but their impacts on aquatic organisms are not yet well studied. The present study investigated the effects of exposure to the antipsychotic drug, haloperidol on the behavioral, hematological and biochemical parameters in juvenile Clarias gariepinus. The fishes were exposed to 0.12, 0.24 and 0.48 mg/L haloperidol for 15 days and later withdrawn from the toxicant and allowed to recover for 5 days. Blood was sampled on days 1, 5, 10, 15, and after the 5-day recovery for hematological and biochemical analysis. The pack cell volume (PCV), red blood cells (RBC), hemoglobin (Hb), reticulocytes and lymphocyte counts were significantly reduced in the exposed fish. The neutrophil counts were increased while that of monocytes, basophils and eosinophils were not affected by the drug. The mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were not different from the control on exposure to the drug. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and acid phosphatase (ACP); and serum creatinine, bile acid and bilirubin were increased on 15-day exposure to the drug. The activity of the clotting factor fibrinogen was reduced compared to the control after exposure to the drug. Haloperidol at concentrations used on 15-day exposure were toxic to fish, but the effect appeared short-lived, as it dissipated on 5-day withdrawal from the drug. While further studies are needed to ascertain the impact of prolonged exposure to environmentally relevant concentrations, caution is advised to avoid eco-toxicological damage to aquatic organisms.

Sex-dependent effects of long-term clozapine or haloperidol medication on red blood cells and liver iron metabolism in Sprague Dawley rats as a model of metabolic syndrome

BACKGROUND

Patients with liver diseases often have some form of anemia. Hematological dyscrasias are known side effects of antipsychotic drug medication and the occurrence of agranulocytosis under clozapine is well described. However, the sex-dependent impact of clozapine and haloperidol on erythrocytes and symptoms like anemia, and its association with hepatic iron metabolism has not yet been completely clarified. Therefore, in the present study, we investigated the effect of both antipsychotic drugs on blood parameters and iron metabolism in the liver of male and female Sprague Dawley rats.

METHODS

After puberty, rats were treated orally with haloperidol or clozapine for 12 weeks. Blood count parameters, serum ferritin, and liver transferrin bound iron were determined by automated counter. Hemosiderin (Fe³⁺) was detected in liver sections by Perl's Prussian blue staining. Liver hemoxygenase (HO-1), 5'aminolevulinate synthase (ALAS1), hepcidin, heme-regulated inhibitor (HRI), cytochrome P4501A1 (CYP1A1) and 1A2 (CYP1A2) were determined by Western blotting.

RESULTS

We found anemia with decreased erythrocyte counts, associated with lower hemoglobin and hematocrit, in females with haloperidol treatment. Males with clozapine medication showed reduced hemoglobin and increased red cell distribution width (RDW) without changes in erythrocyte numbers. High levels of hepatic hemosiderin were found in the female clozapine and haloperidol medicated groups. Liver HRI was significantly elevated in male clozapine medicated rats. CYP1A2 was significantly reduced in clozapine medicated females.

CONCLUSIONS

The characteristics of anemia under haloperidol and clozapine medication depend on the administered antipsychotic drug and on sex. We suggest that anemia in rats under antipsychotic drug medication is a sign of an underlying liver injury induced by the drugs. Changing hepatic iron metabolism under clozapine and haloperidol may help to reduce these effects of liver diseases.

Clozapine induces an acute proinflammatory response that is attenuated by inhibition of inflammasome signaling: implications for idiosyncratic drug-induced agranulocytosis

Although clozapine is a highly efficacious schizophrenia treatment, it is under-prescribed due to the risk of idiosyncratic drug-induced agranulocytosis (IDIAG). Clinical data indicate that most patients starting clozapine experience a transient immune response early in treatment and a similar response has been observed in clozapine-treated rats, but the mechanism by which clozapine triggers this transient inflammation remains unclear. Therefore, the aim of this study was to characterize the role of inflammasome activation during the early immune response to clozapine using in vitro and in vivo models. In both differentiated and nondifferentiated human monocytic THP-1 cells, clozapine, but not its structural analogues fluperlapine and olanzapine, caused inflammasome-dependent caspase-1 activation and IL-1β release that was inhibited using the caspase-1 inhibitor yVAD-cmk. In Sprague Dawley rats, a single dose of clozapine caused an increase in circulating neutrophils and a decrease in lymphocytes within hours of drug administration along with transient spikes in the proinflammatory mediators IL-1β, CXCL1, and TNF-α in the blood, spleen, and bone marrow. Blockade of inflammasome signaling using the caspase-1 inhibitor VX-765 or the IL-1 receptor antagonist anakinra attenuated this inflammatory response. These data indicate that caspase-1-dependent IL-1β production is fundamental for the induction of the early immune response to clozapine and, furthermore, support the general hypothesis that inflammasome activation is a common mechanism by which drugs associated with the risk of idiosyncratic reactions trigger early immune system activation. Ultimately, inhibition of inflammasome signaling may reduce the risk of IDIAG, enabling safer, more frequent use of clozapine in patients.

Fluoxetine in the environment may interfere with the neurotransmission or endocrine systems of aquatic animals

Antidepressants are extensively used to treat the symptoms of depression in humans, and the environmentally discharged drugs potentially threaten aquatic organisms. In this study, the acute toxic effects of fluoxetine (FLX) were investigated in two aquatic organisms, the freshwater polyp (Hydra magnipapillata) and Javanese medaka (Oryzias javanicus). The median lethal concentration (LC₅₀) of FLX in H. magnipapillata was 3.678, 3.082, and 2.901 mg/L after 24, 48, and 72 h, respectively. Morphological observations of the FLX-exposed H. magnipapillata showed that 1.5 mg/L FLX induced the contraction of the tentacles and body column. The LC₅₀ of FLX in O. javanicus was 2.046, 1.936, 1.532, and 1.237 mg/L after 24, 48, 72, and 96 h, respectively. Observation of the behavior of the FLX-exposed fish showed that FLX reduced their swimming performance at a minimum concentration of 10 µg/L. The half-maximal effective concentration (EC₅₀) of FLX for swimming behavior in O. javanicus was 0.135, 0.108, and 0.011 mg/L after 12, 24, and 96 h, respectively. Transcriptomic analyses indicated that FLX affects various physiological and metabolic processes in both species. FLX exposure induced oxidative stress, reproductive deficiency, abnormal pattern formation, DNA damage, and neurotransmission disturbance in H. magnipapillata, whereas it adversely affected O. javanicus by inducing oxidative stress, DNA damage, endoplasmic reticulum stress, and mRNA instability. Neurotransmission-based behavioral changes and endocrine disruption were strongly suspected in the FLX-exposed fish. These results suggest that FLX affects the behavior and metabolic regulation of aquatic organisms.

Vinpocetine attenuates fluoxetine-induced liver damage in rats; Role of Nrf2 and PPAR-γ

BACKGROUND

Fluoxetine (FLX) has been widely used as first-line treatment in cases of depression and other neuropsychiatric disorders. Although its safety has been approved, the use of FLX was associated with liver injury and chronic liver disease. Vinpocetine (Vinpo), a nootropic drug, possesses antioxidant and anti-inflammatory effects.

OBJECTIVE

This study aimed to evaluate the protective effects of Vinpo on FLX-induced liver damage pointing to the role of peroxisome proliferator-activated receptor-gamma (PPAR-γ) and nuclear factor erythroid 2-related factor 2 (Nrf2).

METHODS

Rats were randomized to four groups: control group, Vinpo group (20 mg/kg/day; orally), FLX group (10 mg/kg/day; orally), and Vinpo + FLX group.

RESULTS

FLX-induced liver damage was evidenced through elevated liver function biomarkers and induced hepatic histopathological changes. Concurrent Vinpo treatment resulted in a significant decrease in hepatotoxicity biomarkers and histopathological alterations. FLX-induced oxidative stress and inflammation were attenuated by Vinpo. In addition, Vinpo attenuated the hepatic NRF2 and HO-1 levels and up-regulated PPAR-γ expression. Moreover, FLX elevated Bcl-2-associated X protein (Bax) mRNA expression and decreased B-cell lymphoma 2 (Bcl2) mRNA expression were markedly reversed by Vinpo.

CONCLUSION

Vinpo possesses ameliorative effects against FLX-induced liver injury in rats. This effect may be due to attenuation of oxidative stress and inflammation, in addition to upregulation of PPAR-γ expression.

The Interaction of Heptakis (2,6-di-O-Methyl)-β-cyclodextrin with Mianserin Hydrochloride and Its Influence on the Drug Toxicity

One tetracyclic antidepressant, mianserin hydrochloride (MIA), has quite significant side effects on a patients’ health. Cyclodextrins, which are most commonly used to reduce the undesirable features of contained drugs within their hydrophobic interior, also have the potential to alter the toxic behavior of the drug. The present paper contains investigations and the characteristics of interaction mechanisms for MIA and the heptakis (2,6-di-O-methyl)-β-cyclodextrin (DM-β-CD) system, and evaluated the effects of the complexation on MIA cytotoxicity. In order to assess whether there was an interaction between MIA and DM-β-CD molecules, isothermal titration calorimetry (ITC) have been chosen. Electrospray ionization mass spectrometry (ESI-MS) helped to establish the complex stoichiometry, and circular dichroism spectroscopy was used to describe the process of complex formation. In order to make a wider interpretative perspective, the molecular docking results have been performed. The viability of Chinese hamster cells were investigated in the presence of DM-β-CD and its complexes with MIA in order to estimate the cytotoxicity of the drug and the conjugate with the chosen cyclodextrin. The viability of B14 cells treated with MIA+DM-β-CD is lower (the toxicity is higher) than with MIA alone, and no protective effects have been observed for complexes of MIA with DM-β-CD in any ratio.

The Emerging Role of the Innate Immune Response in Idiosyncratic Drug Reactions

Idiosyncratic drug reactions (IDRs) range from relatively common, mild reactions to rarer, potentially life-threatening adverse effects that pose significant risks to both human health and successful drug discovery. Most frequently, IDRs target the liver, skin, and blood or bone marrow. Clinical data indicate that most IDRs are mediated by an adaptive immune response against drug-modified proteins, formed when chemically reactive species of a drug bind to self-proteins, making them appear foreign to the immune system. Although much emphasis has been placed on characterizing the clinical presentation of IDRs and noting implicated drugs, limited research has focused on the mechanisms preceding the manifestations of these severe responses. Therefore, we propose that to address the knowledge gap between drug administration and onset of a severe IDR, more research is required to understand IDR-initiating mechanisms; namely, the role of the innate immune response. In this review, we outline the immune processes involved from neoantigen formation to the result of the formation of the immunologic synapse and suggest that this framework be applied to IDR research. Using four drugs associated with severe IDRs as examples (amoxicillin, amodiaquine, clozapine, and nevirapine), we also summarize clinical and animal model data that are supportive of an early innate immune response. Finally, we discuss how understanding the early steps in innate immune activation in the development of an adaptive IDR will be fundamental in risk assessment during drug development. SIGNIFICANCE STATEMENT: Although there is some understanding that certain adaptive immune mechanisms are involved in the development of idiosyncratic drug reactions, the early phase of these immune responses remains largely uncharacterized. The presented framework refocuses the investigation of IDR pathogenesis from severe clinical manifestations to the initiating innate immune mechanisms that, in contrast, may be quite mild or clinically silent. A comprehensive understanding of these early influences on IDR onset is crucial for accurate risk prediction, IDR prevention, and therapeutic intervention.

Evaluation of different almond (Terminalia catappa) extracts against oxidative stress induced by cyclosporine in brain and liver of rats

OBJECTIVES

This study was designed to evaluate the ameliorative effect of almond (Terminalia catappa) leaf (ALE) and stem bark (ABE) extracts on the enzyme activities and oxidative stress markers in the brain and liver tissues of cyclosporine-A (CsA) stressed male albino rats.

METHODS

Eighty-eight adult male rats weighing between 200 and 220 g were randomly distributed to into 11 groups (n=8) and different doses (100 and 200 mg/kg bwt.) of ALE and ABE were administered through oral gavages to the normal rats and 50 mg/kg/bwt/day CsA-stressed, while normal control rats was given a saline solution (p.o), and the treatment lasted for 14 days. Blood plasma, liver and brain tissues were prepared for biochemical analysis.

RESULTS

Neuronal [acetylcholinesterase (AChE) and butrylcholinesterase (BChE) and arginase] enzyme activities and thiobarbituric acid reactive species (TBARS) level, plasma aspartate transferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities, liver non-protein thiol (NPSH) level were analyzed. The results revealed that, the administration of CsA induced a significant increase in neuronal AChE, BChE, arginase, TBARS level, but decreased nitric oxide (NO) level. CsA also increased ALT, AST, and ALP activities in the blood plasma of CsA stress rats compared to normal control, but were significantly reversed respectively (p<0.001) upon treatment with the ALE and ABE dose-dependently.

CONCLUSIONS

The study revealed that ALE and ABE could prevent neuronal dysfunction and liver toxicity induced by CsA administration, however, higher dose (200 mg/kg) of the studied extracts appears to be more potent.

Effects of several atypical antipsychotics closapine, sertindole or ziprasidone on hepatic antioxidant enzymes: Possible role in drug-induced liver dysfunction

Chronic use of atypical antipsychotics may produce hepatic damage. Atypical antipsychotics, including clozapine, sertindole, and ziprasidone, are extensively metabolized by the liver and this process generates toxic-free radical metabolic intermediates which may contribute to liver damage. The aim of this study was to investigate whether clozapine, sertindole, or ziprasidone affected hepatic antioxidant defense enzymes which consequently led to disturbed redox homeostasis. The expression and activity of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT), and glutathione-S-transferases (GST) were measured in rat livers at doses corresponding to human antipsychotic therapy. Clozapine increased activity of SOD types 1 and 2, GR and GST, but reduced CAT activity. Sertindole elevated activities of both SODs. In ziprasidone-treated rats only decreased CAT activity was found. All three antipsychotics produced mild-to-moderate hepatic histopathological changes categorized as regenerative alterations. No apparent signs of immune cell infiltration, microvesicular or macrovesicular fatty change, or hepatocytes in mitosis were observed. In conclusion, a 4-week long daily treatment with clozapine, sertindole, or ziprasidone altered hepatic antioxidant enzyme activities and induced histopathological changes in liver. The most severe alterations were noted in clozapine-treated rats. Data indicate that redox disturbances may contribute to liver dysfunction after long-term atypical antipsychotic drug treatment.

Antidepressants- and antipsychotics-induced hepatotoxicity

Drug-induced liver injury (DILI) is a serious health burden. It has diverse clinical presentations that can escalate to acute liver failure. The worldwide increase in the use of psychotropic drugs, their long-term use on a daily basis, common comorbidities of psychiatric and metabolic disorders, and polypharmacy in psychiatric patients increase the incidence of psychotropics-induced DILI. During the last 2 decades, hepatotoxicity of various antidepressants (ADs) and antipsychotics (APs) received much attention. Comprehensive review and discussion of accumulated literature data concerning this issue are performed in this study, as hepatotoxic effects of most commonly prescribed ADs and APs are classified, described, and discussed. The review focuses on ADs and APs characterized by the risk of causing liver damage and highlights the ones found to cause life-threatening or severe DILI cases. In parallel, an overview of hepatic oxidative stress, inflammation, and steatosis underlying DILI is provided, followed by extensive review and discussion of the pathophysiology of AD- and AP-induced DILI revealed in case reports, and animal and in vitro studies. The consequences of some ADs and APs ability to affect drug-metabolizing enzymes and therefore provoke drug–drug interactions are also addressed. Continuous collecting of data on drugs, mechanisms, and risk factors for DILI, as well as critical data reviewing, is crucial for easier DILI diagnosis and more efficient risk assessment of AD- and AP-induced DILI. Higher awareness of ADs and APs hepatotoxicity is the prerequisite for their safe use and optimal dosing.

Investigation of Clozapine and Olanzapine Reactive Metabolite Formation and Protein Binding by Liquid Chromatography-Tandem Mass Spectrometry

Drug-induced toxicity has, in many cases, been linked to oxidative metabolism resulting in the formation of reactive metabolites and subsequent covalent binding to biomolecules. Two structurally related antipsychotic drugs, clozapine (CLZ) and olanzapine (OLZ), are known to form similar nitrenium ion reactive metabolites. CLZ-derived reactive metabolites have been linked to agranulocytosis and hepatotoxicity. We have studied the oxidative metabolism of CLZ and OLZ as well as two known metabolites of CLZ, desmethyl-CLZ (DCLZ), and CLZ-N-oxide (CLZ-NO), using in vitro rat liver microsomal (RLM) incubations with glutathione (GSH) trapping of reactive metabolites and liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS). Reactive metabolite binding to selected standard peptides and recombinant purified human proteins was also evaluated. Bottom-up proteomics was performed using two complementary proteases, prefractionation of peptides followed by LC-HRMS/MS for elucidating modifications of target proteins. Induced RLM was selected to form reactive metabolites enzymatically to assess the complex profile of reactive metabolite structures and their binding potential to standard human proteins. Multiple oxidative metabolites and several different GSH adducts were found for CLZ and OLZ. Modification sites were characterized on human glutathione S-transferase (hGST) alpha 1 (OLZ-modified at Cys112), hGST mu 2 (OLZ at Cys115), and hGST pi (CLZ, DCLZ, CLZ-NO and OLZ at Cys170), human microsomal GST 1 (hMGST1, CLZ and OLZ at Cys50), and human serum albumin (hSA, CLZ at Cys34). Furthermore, two modified rat proteins, microsomal GST 1 (CLZ and OLZ at Cys50) and one CYP (OLZ-modified, multiple possible isoforms), from RLM background were also characterized. In addition, direct effects of the reactive metabolite modifications on proteins were observed, including differences in protease cleavage specificity, chromatographic behavior, and charge-state distributions.

The effect of voluntary wheel running on the antioxidant status is dependent on sociability conditions

Voluntary wheel running is widely used as a physical activity (PA) model in rodents, but most studies investigate the beneficial effects of this intervention in socially isolated mice. Social isolation stress (SIS) is associated with vulnerability to oxidative stress and reduced mitochondrial activity. Thus, the aim of this study was to investigate the effects of free access to a running wheel for 21 days on the various markers of the cellular redox/antioxidant status as well as mitochondrial function of mice subjected to SIS or maintained in groups of 3 in the homecage. SIS increased thiobarbituric acid reactive substance (TBARS) levels in the cerebral cortex, and PA intervention was not able to reverse such alteration. PA reduced TBARS levels in the liver of grouped mice and gastrocnemius of socially isolated mice. PA increased nonprotein thiol (NPSH) levels in the cerebral cortex of grouped mice. Furthermore, socially isolated mice presented lower glutathione peroxidase (GPx) activity in the cerebellum and gastrocnemius, and glutathione reductase (GR) activity in the cerebral cortex and liver. By contrast, SIS induced higher GPx activity in the cerebral cortex and heart. PA reduced GPx (cerebral cortex) and GR (cerebral cortex and liver) activities of socially isolated mice. SIS caused higher activity of mitochondrial complexes I and II in the cerebral cortex, and the PA paradigm was not able to alter this effect. Interestingly, the PA produced antidepressant-like effect at both SIS and control groups. In conclusion, the results showed the influence of SIS for the effects of PA on the antioxidant status, but not on the mitochondrial function and emotionality.

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PA intervention produces antioxidant responses dependent on sociability conditions.

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SIS induces mitochondria function and antioxidant defense abnormalities.

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Running produces antidepressant-like behavior and does not change the ambulation.

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The distance travelled on the running wheel is correlated with immobility time in the TST.

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The lipoperoxidation index is negatively correlated with time spent on the running wheel.

Determination of oxidative stress parameters in fluoxetine users

Fluoxetine (FLU), a selective serotonin reuptake inhibitor, is the first line in depression treatment and it is involved in oxidative stress (OE). Thus, this study aimed to analyze the OE parameters in patients diagnosed with depression and treated with FLU. Were evaluated 121 volunteers divided into two groups: 58 fluoxetine users (with major depression) and 63 non-fluoxetine users (control group, without major depression). The OE was evaluated by determining the levels of malondialdehyde (MDA), total antioxidant power (FRAP) and activity of antioxidant enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD). MDA, FRAP, GPx and SOD were dosed in plasma. The influence of age, smoking, alcoholism, comorbidities, use of another drugs and antioxidants in the OE were evaluated. The results were compared between the groups. In relation to the fluoxetine daily dose, MDA presented higher levels in patients using 20 mg daily FLU when compared to the control group, as well as the activity of the GPx enzyme and the FRAP levels. In this way, the use of fluoxetine may interfere with the OE parameters, causing an increase in OE levels.

Redox metabolism modulation as a mechanism in SSRI toxicity and pharmacological effects

Depressive disorders are amongst the greatest mental health challenges, with an increasing number of patients being diagnosed each year. Though it has not yet been fully elucidated, redox metabolism imbalances and oxidative stress seem to play a major role in the pathogenesis of depressive disorders. Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed antidepressants, considered to have a better tolerability. However, several adverse effects have been reported and the mechanisms involved in their pharmacological activity are not entirely understood. SSRIs have been shown to influence the redox metabolism, which could be involved in their toxicity and pharmacological effects. A comparative analysis of published in vivo and in vitro data regarding the activity of SSRIs on the redox metabolism pathways has been performed in this paper, with an emphasis on mechanistical aspects. Furthermore, a comparison between oxidative stress biomarker levels reported by different studies was attempted. The reviewed data point towards both pro- and antioxidant effects of SSRIs, dependent on tissue/cell type and dose/concentration, suggest a redox modulating potential of these compounds. In hepatic and testicular tissue, the majority of reviewed studies reported pro-oxidant effects, with possible implications towards the hepatotoxicity and sexual dysfunction that were reported following SSRI treatment; while in brain, the most common findings were antioxidant effects that could partially explain their antidepressant activity. However, given the heterogeneity of the reviewed data, further research is needed to fully understand the impact of SSRIs on redox metabolism and its implications.

Acute exposure of zebrafish (Danio rerio) larvae to environmental concentrations of selected antidepressants: Bioaccumulation, physiological and histological changes

Antidepressants have been detected in surface waters worldwide at ng-μg/L concentration. These compounds can exert adverse effects on fish even at low levels. But, all previous analyses have concentrated on adult fish. The aim of the study was to assess the effect of environmental concentrations of sertraline, paroxetine, fluoxetine and mianserin, and their mixtures on such unusual endpoints as physiological and histological changes of zebrafish (Danio rerio) larvae. We also determined the bioconcentration of the pharmaceuticals. Fish Embryo Toxicity test was used to analyze the influence on developmental progression. Histological sections were stained with hematoxylin and eosin. Proliferating cells in liver were determined immunohistochemically by detection of Proliferating Cell Nuclear Antigens. The bioconcentration factor was measured by liquid chromatography coupled to mass spectrometry. Pharmaceuticals were used at low, medium and high concentrations in mixtures and at medium concentration as single compound. Exposure to the analyzed pharmaceuticals increased the rate of abnormal embryo and larvae development, accelerated the hatching time and affected the total hatching rate. Three-times lower proliferation of hepatocytes was observed in larvae exposed to paroxetine, mianserin, sertraline and the mixture of the pharmaceuticals at the highest concentrations. The highest bioaccumulation factor (BCF) was obtained for sertraline. The BCF of the analyzed compounds was higher if the organisms were exposed to the mixtures than to single pharmaceuticals. To conclude, the exposure of zebrafish larvae to selected antidepressants and their mixtures may cause disturbances in the organogenesis of fish even at environmental concentrations.

Clozapine increased c-Fos protein expression in several brain subregions of socially isolated rats

Chronic social stress and/or pharmacological treatments differentially modulate the expression of c-Fos, a marker of neuronal activity, in subregions of the rat brain. Here, we examined the effect of the atypical antipsychotic Clozapine (Clz) (20 mg/kg/day for 3 weeks) on the neuronal activation pattern of c-Fos protein expression in stress-relevant brain subregions of adult male Wistar rats exposed to chronic social isolation (CSIS: 3 weeks), an animal model of depression and schizophrenia, and controls. The protein expression of c-Fos was also used to map neuronal populations in brain subregions activated by CSIS alone. Subregions which showed significantly increased c-Fos protein expression following CSIS included the retrosplenial cortex (RSC), (subregions:RSC granular cortex, c region (RSGc) and dysgranular (RSD)), dentate gyrus, dorsal (DGd), paraventricular thalamic nucleus, posterior part (PVP), lateral (LA)/basolateral (BL) complex of amygdala, caudate putamen (CPu) and accumbens nucleus, shell (AcbSh). Increases in c-Fos protein expression in the RSGc, RSD, DGd, PVP, LA/BL complex of amygdala and striatum (CPu, Acb Core (AcbC) and AcbSh) following Clz treatment in controls were found. Clz applied simultaneously with CSIS modulated neuronal activity in CPu, AcbC and AcbSh subregions compared to CSIS alone, increasing c-Fos protein expression. Furthermore, Clz revealed synergistic effects with CSIS in the CA1d and PVP. These identified neural circuits reflect brain subregions activated following CSIS and/or Clz administration. These data further contribute to the understanding of the effectiveness of Clz in the modulation of brain subregion activation in response to CSIS.

Liver Proteome of Mice with Distinct Genetic Susceptibilities to Fluorosis Treated with Different Concentrations of F in the Drinking Water

Appropriate doses of fluoride (F) have therapeutic action against dental caries, but higher levels can cause disturbances in soft and mineralized tissues. Interestingly, the susceptibility to the toxic effects of F is genetically determined. This study evaluated the effects of F on the liver proteome of mice susceptible (A/J) or resistant (129P3/J) to the effects of F. Weanling male A/J (n = 12) and 129P3/J (n = 12) mice were housed in pairs and assigned to two groups given low-F food and drinking water containing 15 or 50 ppm F for 6 weeks. Liver proteome profiles were examined using nano-LC-ESI-MS/MS. Difference in expression among the groups was determined using the PLGS software. Treatment with the lower F concentration provoked more pronounced alterations in fold change in liver proteins in comparison to the treatment with the higher F concentration. Interestingly, most of the proteins with fold change upon treatment with 15 ppm F were increased in the A/J mice compared with their 129P3/J counterparts, suggesting an attempt of the former to fight the deleterious effects of F. However, upon treatment with 50 ppm F, most proteins with fold change were decreased in the A/J mice compared with their 129P3/J counterparts, especially proteins related to oxidative stress and protein folding, which might be related to the higher susceptibility of the A/J animals to the deleterious effects of F. Our findings add light into the mechanisms underlying genetic susceptibility to fluorosis.

Potential Adverse Cardiovascular Effects of Treatment With Fluoxetine and Other Selective Serotonin Reuptake Inhibitors (SSRIs) in Patients With Geriatric Depression: Implications for Atherogenesis and Cerebromicrovascular Dysregulation

Late life depression is an important public health problem, which associates with increased risk of morbidity and mortality. Selective serotonin reuptake inhibitors (SSRIs), including fluoxetine, are often prescribed to treat geriatric depression. There is increasing evidence that fluoxetine and other SSRIs exert a wide range of cardiovascular side effects. Furthermore, there is evidence that aging may increase plasma level of SSRIs. In this overview, the potential role of side effects of treatment with fluoxetine and other SSRIs in the pathogenesis of age-related cardiovascular diseases, including atherogenesis, cardiac pathologies, and cerebromicrovascular impairment, is discussed.

Subregion-specific Protective Effects of Fluoxetine and Clozapine on Parvalbumin Expression in Medial Prefrontal Cortex of Chronically Isolated Rats

Dysregulation of GABAergic system is becoming increasingly associated with depression, psychiatric disorder that imposes severe clinical, social and economic burden. Special attention is paid to the fast-spiking parvalbumin-positive (PV+) interneurons, GABAergic neurons which are highly susceptible to redox dysregulation and oxidative stress and implicated in a variety of psychiatric diseases. Here we analyzed the number of PV+ and cleaved caspase-3-positive (CC3+) cells in the rat medial prefrontal cortical (mPFC) subregions following chronic social isolation (CSIS), an animal model of depression and schizophrenia. Also, we examined potential protective effects of antidepressant fluoxetine (FLX) and atypical antipsychotic clozapine (CLZ) on the number of these cells in mPFC subregions, when applied parallel with CSIS in doses that correspond to therapeutically effective ones in patients. Immunofluorescence analysis revealed decreased number of PV+ cells in cingulate cortex area 1, prelimbic area (PrL), infralimbic area (IL) and dorsal peduncular cortex of the mPFC in isolated rats, which coincided with depressive- and anxiety-like behaviors. In addition, CSIS-induced increase in the number of CC3+ cells was detected in aforementioned subregions of mPFC. Treatments with either FLX or CLZ prevented behavioral changes, decrease in PV+ and increase in CC3+ cell numbers in PrL and IL subregions in isolated rats. These results indicate the importance of intact GABAergic signaling in these areas for resistance against CSIS-induced behavioral changes, as well as subregion-specific protective effects of FLX and CLZ in mPFC of CSIS rats.

In vitro screening of cell bioenergetics to assess mitochondrial dysfunction in drug development

Drug-induced mitochondrial toxicity is considered as a common cellular mechanism that can induce a variety of organ toxicities. In the present manuscript, 17 in vitro mitochondrial toxic drugs, reported to induce Drug-Induced Liver Injury (DILI) and 6 non-mitochondrial toxic drugs (3 with DILI and 3 without DILI concern), were tested in HepG2 cells using a bioenergetics system. The 17 mitochondrial toxic drugs represent a wide variety of mitochondrial dysfunctions as well as DILI and include 4 pairs of drugs which are structurally related but associated with different DILI concerns in human. Cell bioenergetics were measured using the XF96e analyzer which simultaneous monitor oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), indirect measurements of oxidative phosphorylation and glycolysis, respectively. OCR associated with ATP production, maximal respiration, proton leak and spare respiratory capacity, were also assessed. Duplicate experiments resulted in a sensitivity of 82% (14/17) and specificity of 83% (5/6). The addition of stressors improved specificity considerably. Cut-offs, statistics and rules are clearly discussed to facilitate the use of this assay for screening purposes. Overall, the authors consider that this assay should be part of the battery of safety screening assays at early stages of drug development.

Olive oil and leaf extract prevent fluoxetine-induced hepatotoxicity by attenuating oxidative stress, inflammation and apoptosis

Olive oil and leaf extract have several health benefits; however, their beneficial effect against fluoxetine-induced liver injury has not been investigated. The present study aimed to scrutinize the impact of fluoxetine on the liver of rats and to evaluate the protective effects of olive oil and leaf extract. Rats received fluoxetine orally at dose of 10 mg/kg body weight for 7 consecutive days. The fluoxetine-induced rats were concurrently treated with olive oil or leaf extract. At the end of the experiment, blood and liver samples were collected for analysis. Fluoxetine administration significantly increased circulating ALT, AST, ALP and the pro-inflammatory cytokines TNF-α and IL-1β levels in rats. Histological analysis showed several alterations, such as inflammatory cells infiltration, hepatocyte vacuolation and dilated sinusoids in the liver of fluoxetine-induced rats. Concurrent supplementation of olive oil and olive leaf extract significantly reduced circulating liver function marker enzymes and pro-inflammatory cytokines, and prevented fluoxetine-induced histological alterations. Both olive oil and leaf extract significantly decreased liver lipid peroxidation and nitric oxide, and ameliorated liver glutathione, superoxide dismutase, catalase and glutathione peroxidase. In addition, olive oil and leaf extract prevented fluoxetine-induced apoptosis in the liver of rats as evidenced by decreased expression of Bax and caspase-3, and up-regulated expression of Bcl-2. In conclusion, olive oil and leaf extract protect against fluoxetine-induced liver injury in rats through attenuation of oxidative stress, inflammation and apoptosis.

Fluoxetine reverses behavior changes in socially isolated rats: role of the hippocampal GSH-dependent defense system and proinflammatory cytokines

Exposure of an organism to chronic social isolation (CSIS) has been shown to have an important role in depression. Fluoxetine (Flx) is a first-line treatment for depression; however, its downstream mechanisms of action beyond serotonergic signaling remain ill-defined. We investigated the effect of 3 weeks of Flx (15 mg/kg/day) treatment on behavioral changes and protein expression/activity of the GSH-dependent defense system, including reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GLR), and glutathione S-transferase (GST), as well as catalase (CAT), in the hippocampus of rats exposed to 6 weeks of CSIS. The subcellular distributions of nuclear factor-κB (NF-κB), as well as, cytosolic IL-1β and IL-6 protein expression, were also determined. CSIS induced depressive- and anxiety-like behaviors, evidenced by a decrease in sucrose preference and an increase in the number of buried marbles. Moreover, CSIS compromised redox homeostasis, targeting enzymes such as GPx, CAT, GST, and caused NF-κB nuclear translocation with a concomitant increase in IL-6 protein expression, without an effect on IL-1β. Flx treatment reversed CSIS-induced depressive- and anxiety-like behaviors, modulated GSH-dependent defense by increasing GLR and GST activity, and suppressed NF-κB activation and cytosolic IL-6 protein expression in socially isolated rats. The present study suggests that changes in the GSH-dependent defense system, NF-κB activation and increased IL-6 protein expression may have a role in social isolation-induced changes in a rat model of depression and anxiety, and contributes to our understanding of the mechanisms that underlie the antidepressant and anti-inflammatory activity of Flx in socially isolated rats.

Convergence of glycogen synthase kinase 3β and GR signaling in response to fluoxetine treatment in chronically stressed female and male rats

Accumulating evidence strongly suggest that impaired glucocorticoid receptor (GR) signaling is involved in stress-related mood disorders, and nominate GR as a potential target for antidepressants (ADs). It is known that different classes of ADs affects the GR action via modifying its phosphorylation, while the mechanism through which ADs alter GR phosphorylation targeted by GSK3β, a kinase modulated via serotonin neurotransmission, are unclear. On this basis, we investigated whether GSK3β-GR signaling could be a convergence point of fluoxetine action on brain function and behavior, by examining its effect on GSK3β targeted-GR phosphorylation on threonine 171 (pGR171), and expression of GR-regulated genes in the hippocampus of female and male rats exposed to chronic isolation stress. Stress induced sex-specific GSK3β-targeted phosphorylation of pGR171 in the nucleus of the hippocampus of stressed animals. Namely, while in females stress triggered coupled action of GSK3β-pGR171 signaling, in males changes in pGR171 levels did not correspond to GSK3β activity. On the other hand, fluoxetine managed to up-regulate this pathway in sex-unbiased manner. Furthermore, fluoxetine reverted stress-induced changes in most of the analyzed genes in males, CRH, 5-HT1a and p11, while in females its effect was limited to CRH. These data further suggest that pGR171 signaling affects cellular localization of GR in response to chronic stress and fluoxetine in both sexes. Collectively, our results describe a novel convergence point between GR signaling and GSK3β pathway in rat hippocampus in response to stress and fluoxetine in both sexes and its involvement in fluoxetine-regulated brain function in males.

Olanzapine alleviates oxidative stress in the liver of socially isolated rats

Olanzapine, an antipsychotic drug, is used to treat depressive disorder, but its effects on the liver, the main site of drug metabolism, still remain elusive. We studied the effects of 3 weeks of olanzapine treatment (7.5 mg/kg per day) on the malondialdehyde (MDA) and protein carbonyl (PCO) contents, protein expression of copper/zinc superoxide dismutase (CuZnSOD), and activity of total superoxide dismutase (SOD), as well as catalase (CAT) protein expression and activity levels in the liver cytosol of rats exposed to 6 weeks of chronic social isolation (CSIS), which causes depressive- and anxiety-like behaviors. Increased cytosolic MDA in CSIS rats (vehicle- or olanzapine-treated) indicated hepatic oxidative stress. Increase in PCO and CAT activity associated with unchanged total SOD activity following CSIS also confirm the presence of oxidative stress. Chronic olanzapine treatment in CSIS prevented increase in PCO without an effect on MDA content. Increased SOD activity in olanzapine-treated (controls and CSIS) groups compared with corresponding vehicle-treated groups and decreased CAT activity in olanzapine-treated CSIS rats compared with vehicle-treated CSIS group was found. The data suggest that chronic olanzapine treatment has a protective effect on hepatic protein oxidation and improves antioxidant defense. The beneficial effects of olanzapine may be due to its free radical scavenging properties and antioxidant activity.

Protective effects of melatonin on long-term administration of fluoxetine in rats

The degree and consequence of tissue injury are highly regarded during long-term exposure to selective antidepressant fluoxetine. Melatonin has been shown to palliate different lesions by scavenging free radicals, but its role in the reduction of the fluoxetine-induced injuries has been little known. Thirty-six mature male Wistar rats were randomly assigned into control and experimental groups. The experimental rats were included as following; 24mg/kg/bw fluoxetine for 4 weeks; 1mg/kg/bw melatonin for 4 weeks; fluoxetine+1-week melatonin, fluoxetine+2-week melatonin and fluoxetine+4-week melatonin. In the current experiment, we investigated weight gain, hematological and biochemical parameters, pathological injuries and oxidative status. We noted the positive effect of melatonin in weight loss of fluoxetine-treated rats (p<0.05). The significant reduction of superoxide dismutase, glutathione peroxidase, catalase activities in blood, liver, and kidneys and changes in serum total antioxidant capacity caused by fluoxetine were reversed by melatonin (p<0.05). Melatonin reduced the increased lipid peroxidation and transaminase activity in rats received fluoxetine (p<0.05). We also showed the potency of fluoxetine in inducing leukopenia, thrombocytopenia and hypochromic and macrocytic anemia which was blunted by melatonin. Both RBCs and platelets indices were also corrected. Rats received melatonin in combination with fluoxetine showed a reduction in the severity of degeneration and inflammatory changes in different tissues, brain, heart, liver, lungs, testes and kidneys as compared to the fluoxetine group. Therefore, melatonin fundamentally reversed the side effects of fluoxetine in the rat model which is comparable to human medicine.

Prefrontal cortical glutathione-dependent defense and proinflammatory mediators in chronically isolated rats: Modulation by fluoxetine or clozapine

Chronic psychosocial stress modulates brain antioxidant systems and causes neuroinflammation that plays a role in the pathophysiology of depression. Although the antidepressant fluoxetine (FLX) represents the first-line treatment for depression and the atypical antipsychotic clozapine (CLZ) is considered as a second-line treatment for psychotic disorders, the downstream mechanisms of action of these treatments, beyond serotonergic or dopaminergic signaling, remain elusive. We examined behavioral changes, glutathione (GSH)-dependent defense and levels of proinflammatory mediators in the prefrontal cortex (PFC) of adult male Wistar rats exposed to 21days of chronic social isolation (CSIS). We also tested the ability of FLX (15mg/kg/day) or CLZ (20mg/kg/day), applied during CSIS, to prevent stress-induced changes. CSIS caused depressive- and anxiety-like behaviors, compromised GSH-dependent defense, and induced nuclear factor-kappa B (NF-κB) activation with a concomitant increase in cytosolic levels of proinflammatory mediators cyclooxigenase-2, interleukin-1beta and tumor necrosis factor-alpha in the PFC. NF-κB activation and proinflammatory response in the PFC were not found in CSIS rats treated with FLX or CLZ. In contrast, only FLX preserved GSH content in CSIS rats. CLZ not only failed to protect against CSIS-induced GSH depletion, but it diminished its levels when applied to non-stressed rats. In conclusion, prefrontal cortical GSH depletion and the proinflammatory response underlying depressive- and anxiety-like states induced by CSIS were prevented by FLX. The protective effect of CLZ, which was equally effective as FLX on the behavioral level, was limited to proinflammatory components. Hence, different mechanisms underlie the protective effects of these two drugs in CSIS rats.

In vitro anti-Candida activity of selective serotonin reuptake inhibitors against fluconazole-resistant strains and their activity against biofilm-forming isolates

Recent research has shown broad antifungal activity of the classic antidepressants selective serotonin reuptake inhibitors (SSRIs). This fact, combined with the increased cross-resistance frequency of the genre Candida regarding the main treatment today, fluconazole, requires the development of novel therapeutic strategies. In that context, this study aimed to assess the antifungal potential of fluoxetine, sertraline, and paroxetine against fluconazole-resistant Candida spp. planktonic cells, as well as to assess the mechanism of action and the viability of biofilms treated with fluoxetine. After 24 h, the fluconazole-resistant Candida spp. strains showed minimum inhibitory concentration (MIC) in the ranges of 20-160 μg/mL for fluoxetine, 10-20 μg/mL for sertraline, and 10-100.8 μg/mL for paroxetine by the broth microdilution method (M27-A3). According to our data by flow cytometry, each of the SSRIs cause fungal death after damaging the plasma and mitochondrial membrane, which activates apoptotic signaling pathways and leads to dose-dependant cell viability loss. Regarding biofilm-forming isolates, the fluoxetine reduce mature biofilm of all the species tested. Therefore, it is concluded that SSRIs are capable of inhibit the growth in vitro of Candida spp., both in planktonic form, as biofilm, inducing cellular death by apoptosis.

Levels of nitric oxide, asymmetric dimethyl arginine, symmetric dimethyl arginine,and L-arginine in patients with obsessive-compulsive disorder

BACKGROUND/AIM

We aimed to investigate and compare to healthy controls the variations in the levels of nitric oxide (NO), asymmetric dimethyl arginine (ADMA), symmetric dimethyl arginine (SDMA), and L-arginine levels in patients with obsessive-compulsive disorder (OCD).

MATERIALS AND METHODS

We enrolled 30 patients with OCD and 30 healthy controls in the study consecutively. Diagnostic interviews of all participants were conducted with the Structured Clinical Interview for Axis I Disorders (SCID-I), and sociodemographic data of the participants were recorded. Patients scoring 10 points or more on the Yale-Brown Obsessive-Compulsive Scale were enrolled in the study.

RESULTS

The NO levels of patients with OCD were increased compared to the control group, but the increase was not statistically significant (P > 0.05). However, patients with OCD had significantly lower levels of ADMA, SDMA, and L-arginine compared with the controls (P < 0.001).

CONCLUSION

We found a significant decrease in ADMA, SDMA, and L-arginine as NO inhibitors between the groups, possibly because of an increase in NO. However, the insignificant increase in NO suggests that ADMA, SDMA, and L-arginine play direct and potentially important roles in OCD biology.

Protective Effects of Caffeic Acid Phenethyl Ester on Fluoxetine-Induced Hepatotoxicity: An Experimental Study

Background. The aim of the study was to analyse the effect of caffeic acid phenethyl ester (CAPE) on fluoxetine-induced hepatotoxicity in rats. Materials and Methods. Group I served as control. Group II received CAPE intraperitoneally. Group III received fluoxetine per orally. Group IV received fluoxetine and CAPE. The total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), and liver enzymes including paraoxonase-1 (PON-1), aspartate transaminase, and alanine transaminase levels were measured. Liver tissues were processed histopathologically for evaluation of liver injury and to validate the serum enzyme levels. Results. An increase in TOS and OSI and a decrease in TAC and PON-1 levels in serum and liver tissues of Group III were observed compared to Groups I and II. After treatment with CAPE, the level of TOS and OSI decreased while TAC and PON-1 increased in serum and liver in Group IV. Histopathological examination of the liver revealed hepatic injury after fluoxetine treatment and reduction of injury with CAPE treatment. Conclusion. Our results suggested that CAPE treatment provided protection against fluoxetine toxicity. Following CAPE treatment with fluoxetine-induced hepatotoxicity, TOS and OSI levels decreased, whereas PON-1 and TAC increased in the serum and liver.

Oxidative stress favours herpes virus infection in vertebrates: a meta-analysis

Herpes viruses are responsible for a variety of pathological effects in humans and in both wild and domestic animals. One mechanism that has been proposed to facilitate replication and activity of herpes viruses is oxidative stress (OS). We used meta-analytical techniques to test the hypotheses that (1) herpes virus infection causes OS and (2) supplementation of antioxidants reduces virus load, indicating that replication is favoured by a state of OS. Results based on studies on mammals, including humans, and birds show that (1) OS is indeed increased by herpes virus infection across multiple tissues and species, (2) biomarkers of OS may change differently between tissues, and (3) the effect size does not differ among different virus strains. In addition, the increase of oxidative damage in blood (tissue commonly available in ecological studies) was similar to that in the tissues most sensitive to the herpes virus. Our results also show that administration of antioxidants reduces virus yield, indicating that a condition of OS is favorable for the viral replication. In addition, some antioxidants may be more efficient than others in reducing herpes virus yield. Our results point to a potential mechanism linking herpes virus infection to individual health status.

The Role of Oxidative Stress and Antioxidants in Liver Diseases

A complex antioxidant system has been developed in mammals to relieve oxidative stress. However, excessive reactive species derived from oxygen and nitrogen may still lead to oxidative damage to tissue and organs. Oxidative stress has been considered as a conjoint pathological mechanism, and it contributes to initiation and progression of liver injury. A lot of risk factors, including alcohol, drugs, environmental pollutants and irradiation, may induce oxidative stress in liver, which in turn results in severe liver diseases, such as alcoholic liver disease and non-alcoholic steatohepatitis. Application of antioxidants signifies a rational curative strategy to prevent and cure liver diseases involving oxidative stress. Although conclusions drawn from clinical studies remain uncertain, animal studies have revealed the promising in vivo therapeutic effect of antioxidants on liver diseases. Natural antioxidants contained in edible or medicinal plants often possess strong antioxidant and free radical scavenging abilities as well as anti-inflammatory action, which are also supposed to be the basis of other bioactivities and health benefits. In this review, PubMed was extensively searched for literature research. The keywords for searching oxidative stress were free radicals, reactive oxygen, nitrogen species, anti-oxidative therapy, Chinese medicines, natural products, antioxidants and liver diseases. The literature, including ours, with studies on oxidative stress and anti-oxidative therapy in liver diseases were the focus. Various factors that cause oxidative stress in liver and effects of antioxidants in the prevention and treatment of liver diseases were summarized, questioned, and discussed.

Fluoride-induced oxidative stress is involved in the morphological damage and dysfunction of liver in female mice

Fluoride (F), one of the most toxic environmental and industrial pollutants, is known to exert hepatotoxicity. The contribution of oxidative stress to the F tolerance of liver remains largely unknown. In this study, the morphological and ultrastructural characteristics of liver were observed using hematoxylin and eosin staining and transmission electron microscopy (TEM), respectively. Oxidative-stress participations was analysed and the mRNA expression levels of catalase (Cat), glutathione peroxidase 1 (GSH-Px1), nitric oxide synthase 2 (NOS2), and superoxide dismutase 1 (SOD1) were investigated by real-time PCR. Changes in liver-function parameters were also detected. Results showed that the reactive content of reactive oxygen species increased significantly, whereas SOD and GSH-Px activities, as well as total anti-oxidising capability (T-AOC), decreased significantly, with increased nitric oxide (NO) and malondialdehyde (MDA) contents in liver and serum after 70days of F treatment. The mRNA expression levels of Cat, GSH-Px1, and SOD were significantly downregulated, whereas NOS2 mRNA expression level was up upregulated, after F treatment for 70days. Light microscopy also revealed that hepatocytes were fused into pieces; cell boundaries were unclear, and nuclei were lightly stained. TEM further showed that hepatocytes were characterised by vague nuclear and mitochondrial membranes, dilated endoplasmic reticulum, and aggravated vacuolar degeneration. Activities of alanine transaminase, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase, as well as the level of total bilirubin in serum increased. Overall, these results indicated that F interfered with the balance of antioxidase activity and morphological changes in liver, which were involved in mouse liver dysfunction.

Olanzapine modulation of hepatic oxidative stress and inflammation in socially isolated rats

Olanzapine, an atypical antipsychotic, is efficient in stress associated psychiatric diseases, but its effect on the liver, a primary organ for drug activation and detoxification, still remains unclear. The effect of olanzapine administration (7.5mg/kg/day), on rat hepatic glutathione (GSH)-dependent defense and proinflammatory cytokines following 6weeks of chronic social isolation (CSIS), which causes depressive- and anxiety-like behavior in adult male Wistar rats, was investigated. The subcellular distribution of nuclear factor-κB (NF-κB), cytosolic inducible nitric oxide synthase (iNOS) protein levels and hepatic histological alterations were also determined. Decreased GSH content and glutathione reductase activity associated with increased catalase and glutathione S-transferase activity following CSIS indicated hepatic oxidative stress. Moreover, CSIS caused NF-κB nuclear translocation and the concomitant increase in iNOS together with increase in interleukin-1beta and tumor necrosis factor alpha protein levels, but no effect on interleukin-6. Olanzapine treatment suppressed NF-κB activation and iNOS expression and caused modulation of GSH-dependent defense systems but failed to reverse CSIS-induced increase in hepatic proinflammatory cytokines. Portal inflammation, focal hepatocyte necrosis and an increased number of Kupffer cells in CSIS rats (vehicle- or olanzapine-treated) were found. Olanzapine-treated socially reared rats showed portal inflammation and focal hepatocyte necrosis. Data suggest that CSIS compromised GSH-dependent defense, triggered a proinflammatory response and histological alterations in rat liver. Olanzapine treatment partially reversed the alterations in hepatic GSH-dependent defense, but showed no anti-inflammatory effect suggesting that it may provide protective effect against hepatic CSIS-induced oxidative stress, but not against inflammation.

Effect of fluoxetine treatment on mitochondrial bioenergetics in central and peripheral rat tissues

Recent investigations have focused on the mitochondrion as a direct drug target in the treatment of metabolic diseases (obesity, metabolic syndrome). Relatively few studies, however, have explicitly investigated whether drug therapies aimed at changing behavior by altering central nervous system (CNS) function affect mitochondrial bioenergetics, and none has explored their effect during early neonatal development. The present study was designed to evaluate the effects of chronic treatment of newborn male rats with the selective serotonin reuptake inhibitor fluoxetine on the mitochondrial bioenergetics of the hypothalamus and skeletal muscle during the critical nursing period of development. Male Wistar rat pups received either fluoxetine (Fx group) or vehicle solution (Ct group) from the day of birth until 21 days of age. At 60 days of age, mitochondrial bioenergetics were evaluated. The Fx group showed increased oxygen consumption in several different respiratory states and reduced production of reactive oxygen species, but there was no change in mitochondrial permeability transition pore opening or oxidative stress in either the hypothalamus or skeletal muscle. We observed an increase in glutathione S-transferase activity only in the hypothalamus of the Fx group. Taken together, our results suggest that chronic exposure to fluoxetine during the nursing phase of early rat development results in a positive modulation of mitochondrial respiration in the hypothalamus and skeletal muscle that persists into adulthood. Such long-lasting alterations in mitochondrial activity in the CNS, especially in areas regulating appetite, may contribute to permanent changes in energy balance in treated animals.