A study of antioxidant activity in patients with schizophrenia taking atypical antipsychotics

Hyperhomocysteinemia in Treatment with Atypical Antipsychotics is Independent of Metabolic Syndrome

Strong association between homocysteine (Hcy) and metabolic syndrome (MetS) is documented in individuals with schizophrenia and it is suggested that alterations in Hcy levels might be secondary to metabolic changes induced by atypical antipsychotics (AA). Serum paraoxonase (PON-1) activity, which is negatively affected by increased Hcy concentrations are lower in schizophrenia, and this may impact the development of metabolic side effects. Forty-five subjects with schizophrenia and 43 healthy volunteers, matched according to age, gender, smoking habits, and MetS predictors, were enrolled in this study to examine how Hcy level, PON-1 activity, and MetS indicators influence each other in schizophrenic individuals on AA treatment. Serum Hcy concentrations were significantly higher (15 ± 8 μmol/L vs 12 ± 3 μmol/L), and PON activity tended to be impaired (182±82 U/L vs 216 ± 110 U/L) in schizophrenia. Serum Hcy concentrations were not different between subjects with and without metabolic syndrome in study (14±4 μmol/L and 16±9 μmol/L) and control groups (12±3 μmol/L and 13±7 μmol/L), respectively. Similarly, PON and aryl esterase (AE) activities were not different between subjects with and without metabolic syndrome in study (PON: 185±100 U/L and 181±76 U/L; AE: 84±34 kU/L and 89±20 kU/L) and control (PON: 215±111 U/L and 216±113 U/L; AE: 83±27 kU/L and 88±33 kU/L) groups, respectively. . Hcy levels and MetS predictors were not statistically correlated. Results indicate that schizophrenic subjects on AA treatment have increased levels of Hcy compared to healthy controls and this is not influenced by the presence of MetS.

Paraoxonase/Arylesterase Activity of Serum Paraoxonase-1 and Schizophrenia: A Systematic Review and Meta-Analysis

The presence of a pro-oxidant state in patients with schizophrenia may account for the increased risk of atherosclerosis and cardiovascular disease in this group and supports the potential utility of circulating biomarkers of oxidative stress for risk stratification and management. We investigated this issue by conducting a systematic review and meta-analysis of the association between the circulating concentrations of paraoxonase-1, an antioxidant calcium-dependent high-density lipoprotein (HDL)-associated esterase, with paraoxonase and arylesterase activity in schizophrenia. We searched electronic databases from inception to 31 May 2023 for studies investigating paraoxonase-1 in patients with schizophrenia and healthy controls and assessed the risk of bias and the certainty of evidence (PROSPERO registration number: CRD42023435442). Thirteen studies were identified for analysis. There were no significant between-group differences in paraoxonase (standard mean difference, SMD = 0.12, 95% CI -0.23 to 0.48, p = 0.50; extremely low certainty of evidence) or arylesterase activity (SMD = -0.08, 95% CI -0.39 to 0.23, p = 0.61; very low certainty of evidence). However, in meta-regression and subgroup analysis we observed significant associations between the SMD of paraoxonase and age (p = 0.003), HDL-cholesterol (p = 0.029), and study country (p = 0.04), and the SMD of arylesterase and age (p = 0.007), body mass index (p = 0.012), HDL-cholesterol (p = 0.002), and pharmacological treatment for schizophrenia (p < 0.001). In the absence of overall between-group differences, our systematic review and meta-analysis suggests that alterations in paraoxonase-1 may reflect a pro-oxidant state in specific subgroups of patients with schizophrenia that require further assessment in appropriately designed studies.

Obesity, antioxidants and negative symptom improvement in first-episode schizophrenia patients treated with risperidone

Negative symptoms remain a main therapeutic challenge in patients with schizophrenia (SZ). Obesity is associated with more severe negative symptoms after the first episode of psychosis. Oxidative stress caused by an impaired antioxidant defense system is involved in the pathophysiology of SZ. Yet, it is unclear regarding the role of obesity and antioxidants in negative symptom improvements in SZ. Therefore, this longitudinal study was designed to assess the impact of obesity on antioxidant defenses and negative symptom improvements in first-episode SZ patients. A total of 241 medication-naive and first-episode patients with SZ were treated with risperidone for 3 months. Outcome measures including symptoms, body weight, and total antioxidant status (TAS) levels were measured at baseline and the end of the third month. We found that after 12 weeks of treatment with risperidone, the body weight increased and clinical symptoms significantly improved. Baseline body mass index (BMI) was negatively correlated with negative symptom improvement after treatment and an increase in TAS was negatively associated with an increase in BMI only in the high BMI group. More importantly, the TAS × BMI interaction at baseline was an independent predictor of negative symptom improvement. Our longitudinal study indicates that the improvement in negative symptoms by risperidone was associated with baseline BMI and TAS levels in patients with SZ. Baseline BMI and TAS may be a predictor for negative improvement in SZ patients after risperidone treatment.

Risperidone ameliorated 1,2-Diacetylbenzene-induced cognitive impairments in mice via activating prolactin signaling pathways

Cognitive impairment and organic solvent exposure have been becoming public health concerns due to an increasingly aging population, increased life expectancy, urbanization, and industrialization. Converging evidence indicates the link between 1,2-diacetylbenzene (DAB), prolactin (PRL), risperidone, and cognitive impairment. However, these relationships remain unclear. We investigated the therapeutic properties of risperidone in DAB-induced cognitive impairment using both in vivo and in silico methods. Risperidone alleviated DAB-induced cognitive impairment in hippocampal mice, possibly by inhibiting GSK-3β, β-amyloid, CDK5, BACE, and tau hyperphosphorylation. Risperidone also attenuated the activation of TREM-1/DAP12/NLRP3/caspase-1/IL-1β, and TLR4/NF-κB pathways caused by DAB. Furthermore, risperidone inhibited DAB-induced oxidative stress, advanced glycation end products, and proinflammatory cytokines, as well as increased the expression of Nrf2, IL-10, Stat3, MDM2, and catalase activity. On the other hand, risperidone activated the expression of IRS1, PI3K, AKT, BDNF, Drd2, Scna5, and Trt as well as reduced the Bax/Bcl2 ratio and Caspase-3 levels. In silico analyses identified the prolactin signaling pathway, miR-155-5p, miR-34a-5p, and CEBPB as the main molecular mechanisms involved in the pathophysiology of DAB-induced cognitive impairment and targeted by risperidone. Our results suggest that risperidone could be used to treat cognitive impairment caused by organic solvents, especially DAB.

Relationship between Body Composition and Biochemical Parameters with Antioxidant Status in a Healthy Cohort of Postmenopausal Women

An adequate prooxidant–antioxidant balance—which may be influenced by body composition and biochemical status—is essential to maintain human health, especially in circumstances under which the antioxidant defense decreases, such as menopause. The present study aimed to examine the relationship between body composition and biochemical parameters with antioxidant status in a healthy cohort of postmenopausal women. This cross-sectional study was carried out in a cohort of 78 postmenopausal women aged 44–76 years. The body composition profile was assessed through bioelectrical impedance. The determination of the total antioxidant capacity and superoxide dismutase activity was conducted by the colorimetric method, and glutathione peroxidase activity was determined by the enzymatic immunological method. The vitamin D levels were measured by ultra-performance liquid chromatography–tandem mass spectrometry. The mineral status was assessed through flame atomic absorption spectrophotometry. The rest of the biochemical parameters were assessed through an immunoassay. The total antioxidant capacity and antioxidant gap were negatively influenced by body composition (all p ≤ 0.049) and positively related to protein metabolism parameters (all p ≤ 0.048), whereas circulating levels of different micronutrients (all p ≤ 0.048) and enzymes (all p ≤ 0.047) appeared to play an important role in the glutathione peroxidase and superoxide dismutase activities. In conclusion, the menopause-related antioxidant status changes may be influenced by key body composition and biochemical profiles. To confirm this statement, further trials aiming to evaluate the body composition and biochemical intervention-induced changes upon antioxidant defense are needed.

Effects of antipsychotics on antioxidant defence system in patients with schizophrenia: A meta-analysis

Theory of oxidative stress is suggested in the pathophysiology of schizophrenia. To determine the cause of impaired antioxidant defense system in schizophrenia, a meta-analysis was performed by selecting studies published from 1964 to 2021 from Pubmed and Scopus databases. Data were analysed using Comprehensive Meta-Analysis version 2 and calculated effect sizes were compared between unmedicated and medicated patients with schizophrenia and healthy controls. Heterogeneity, publication bias assessments and subgroup analyses of drug-free and drug-naïve patients, and patients treated with atypical and typical antipsychotics were conducted. Subgroup analysis of confounding factors including age, gender, illness duration and patient status was also conducted. We found that glutathione peroxidase (GPx) was significantly decreased in all patients. Significantly lower catalase (CAT), glutathione (GSH) and albumin (ALB) were found in unmedicated patients only. Both groups showed significantly weakened non-enzymatic antioxidant capacity. Subgroup analyses indicated that weakened non-enzymatic antioxidant capacity may be associated with schizophrenia. Antioxidant status was more impaired in drug-free patients compared with other subgroups. This indicated that antipsychotics may improve antioxidant defense system. Although effect sizes were smaller, future studies may focus on the effect of antipsychotic discontinuation. In overall, schizophrenia was associated with impaired antioxidant defense system especially the non-enzymatic antioxidant system.

Metabolic Effects of Aripiprazole and Olanzapine Multiple-Dose Treatment in a Randomised Crossover Clinical Trial in Healthy Volunteers: Association with Pharmacogenetics

Introduction

Aripiprazole and olanzapine are atypical antipsychotics. Both drugs can induce metabolic changes; however, the metabolic side effects produced by aripiprazole are more benign. The aim of the study was to evaluate if aripiprazole and olanzapine alter prolactin levels, lipid and glucose metabolism and hepatic, haematological, thyroid and renal function.

Methods

Twenty-four healthy volunteers received a daily oral dose of 10 mg aripiprazole and 5 mg olanzapine tablets for 5 days in a crossover randomised clinical trial and were genotyped for 51 polymorphisms in 18 genes by qPCR. Drug plasma concentrations were measured by LC–MS. The biochemical and haematological analyses were performed by enzymatic methods.

Results

Olanzapine induced hyperprolactinaemia but aripiprazole did not. Dopamine D3 receptor (DRD3) Ser/Gly and ATP binding cassette subfamily B member 1 (ABCB1) rs10280101, rs12720067 and rs11983225 polymorphisms and cytochrome P450 3A (CYP3A) phenotype had an impact on plasma prolactin levels. C-peptide concentrations were higher after aripiprazole administration and were influenced by catechol-O-methyltransferase (COMT) rs4680 and rs13306278 polymorphisms. Olanzapine and the UDP glucuronosyltransferase family 1 member A1 (UGT1A1) rs887829 polymorphism were associated with elevated glucose levels. CYP3A poor metabolizers had increased insulin levels. Volunteers’ weight decreased significantly during aripiprazole treatment and a tendency for weight gain was observed during olanzapine treatment. Triglyceride concentrations decreased as a result of olanzapine and aripiprazole treatment, and varied on the basis of CYP3A phenotypes and the apolipoprotein C-III (APOC3) rs4520 genotype. Cholesterol levels were also decreased and depended on 5-hydroxytryptamine receptor 2A (HTR2A) rs6314 polymorphism. All hepatic enzymes, platelet and albumin levels, and prothrombin time were altered during both treatments. Additionally, olanzapine reduced the leucocyte count, aripiprazole increased free T4 and both decreased uric acid concentrations.

Conclusions

Short-term treatment with aripiprazole and olanzapine had a significant influence on the metabolic parameters. However, it seems that aripiprazole provokes less severe metabolic changes.

Trial Registration

Clinical trial registration number (EUDRA-CT): 2018-000744-26

Graphical Abstract

Electronic Supplementary Material

The online version of this article (10.1007/s12325-020-01566-w) contains supplementary material, which is available to authorized users.

Comparative Study of the Effects of Atypical Antipsychotic Drugs on Plasma and Urine Biomarkers of Oxidative Stress in Schizophrenic Patients

PURPOSE

Evidence that antipsychotic drugs (ADs) can affect oxidative stress estimated with various biomarkers in schizophrenic patients is controversial and limited. Therefore, in the present study, we assessed the ability of six atypical ADs (clozapine, olanzapine, quetiapine, risperidone, aripiprazole, and ziprasidone) used in schizophrenia treatment to modulate oxidative damage to different biomolecules such as lipids and proteins.

PATIENTS AND METHODS

We measured the levels of oxidative stress markers in plasma and urine: total antioxidant capacity by FRAP (according to a modified method of Benzie & Strain), thiobarbituric acid reactive species - TBARS (spectrophotometric method), 4-hydroxy-2-nonenal (4-HNE) (OxiSelect™ HNE Adduct Competitive ELISA Kit), 3-nitrotyrosine (3-NT) (OxiSelect™ Nitrotyrosine ELISA Kit) in plasma, and F2-isoprostanes (BIOXYTECH^® Urinary 8-epi-Prostaglandin F2α) in the urine of 60 schizophrenic patients (before and after treatment) and in 30 healthy subjects.

RESULTS

Our results showed that in schizophrenic patients levels of lipid peroxidation markers (TBARS, F2-isoprostanes) were higher than in healthy subjects but FRAP in schizophrenic patients was lower than in healthy controls and increased after 4-week treatment with tested ADs. A 4-week treatment with ADs caused the improvement of psychopathology symptoms estimated by Positive and Negative Syndrome Scale (PANSS) that was accompanied by decreased lipid peroxidation (F2-isoprostanes, TBARS; p=2.9x10^-6, p=7.6x10^-5, respectively) and an increase in total antioxidative capacity (FRAP) (p=5.16x10^-16).

CONCLUSION

Atypical antipsychotics especially clozapine, olanzapine and quetiapine demonstrate the effective outcome of antipsychotic treatment, beneficial antioxidative action by reducing lipid peroxidation and increased total plasma antioxidant activity.

A Multi-Omics Analysis of PON1 Lactonase Activity in Relation to Human Health and Disease

Paraoxonase 1 (PON1) enzyme has antioxidative properties and is present in mammalian blood and several other body fluids. In blood, PON1 is usually integrated into the high-density lipoprotein (HDL) cholesterol. PON1 is a highly versatile enzyme displaying diverse functions such as arylesterase, lactonase, and paraoxonase, among others. PON1 activities are usually investigated with artificial substrates, for example, dihydrocoumarin and thiobutyl butyrolactone for lactonase activity. The PON1 enzyme activities measured with different substrates tend to be falsely assumed as being equivalent in the literature, although there are poor or weak correlations among the PON1 enzyme activities with different substrates. In addition, and despite our knowledge of the factors influencing PON1 paraoxonase and arylesterase activities, there is little knowledge of PON1 lactonase activity variations and attendant mechanisms. This is important considering further that the lactonase activity is the native activity of PON1. We report here a multi-omics analysis of PON1 lactonase activity. The influence of genetic variations, particularly of single nucleotide polymorphisms and epigenetic, proteomic, and lipidomic variations on PON1 lactonase activity are reviewed. In addition, the influence of various environmental, clinical, and demographic variables on PON1 lactonase activity is discussed. Finally, we examine the associations between PON1 lactonase activity and health states and common complex diseases such as atherosclerosis, dementias, obesity, and diabetes. To the best of our knowledge, this is the first multi-omics analysis of PON1 lactonase activity with an eye to future applications in basic life sciences and translational medicine and the nuances of critically interpreting PON1 function with lactones as substrates.

Why Should Psychiatrists and Neuroscientists Worry about Paraoxonase 1?

BACKGROUND

Nitro-oxidative stress (NOS) has been implicated in the pathophysiology of psychiatric disorders. The activity of the polymorphic antioxidant enzyme paraoxonase 1 (PON1) is altered in diseases where NOS is involved. PON1 activity may be estimated using different substrates some of which are influenced by PON1 polymorphisms.

OBJECTIVES

1) to review the association between PON1 activities and psychiatric diseases using a standardized PON1 substrate terminology in order to offer a state-of-the-art review; and 2) to review the efficacy of different strategies (nutrition, drugs, lifestyle) to enhance PON1 activities.

METHODS

The PubMed database was searched using the terms paraoxonase 1 and psychiatric diseases. Moreover, the database was also searched for clinical trials investigating strategies to enhance PON1 activity.

RESULTS

The studies support decreased PON1 activity as determined using phenylacetate (i.e., arylesterase or AREase) as a substrate, in depression, bipolar disorder, generalized anxiety disorder (GAD) and schizophrenia, especially in antipsychotic-free patients. PON1 activity as determined with paraoxon (i.e., POase activity) yields more controversial results, which can be explained by the lack of adjustment for the Q192R polymorphism. The few clinical trials investigating the influence of nutritional, lifestyle and drugs on PON1 activities in the general population suggest that some polyphenols, oleic acid, Mediterranean diet, no smoking, being physically active and statins may be effective strategies that increase PON1 activity.

CONCLUSION

Lowered PON1 activities appear to be a key component in the ongoing NOS processes that accompany affective disorders, GAD and schizophrenia. Treatments increasing attenuated PON1 activity could possibly be new drug targets for treating these disorders.

Obesity, altered oxidative stress, and clinical correlates in chronic schizophrenia patients

Antipsychotic pharmacotherapy is strongly obesogenic and is associated with increased oxidative stress in patients with schizophrenia. However, whether these changes reflect psychopathology, antipsychotic efficacy, or some other factor is not known. Our study aims to investigate the degree of oxidative stress in different BMI categories and to identify clinical symptomatology that may be paired with increased oxidative stress in a schizophrenia population. To this end, we performed a cross-sectional study and recruited 89 long-term inpatients with schizophrenia and collected the following variables: plasma malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), routine biochemical analysis, and psychopathology through the Positive and Negative Syndrome Scale (PANSS). The results indicate that the levels of the lipid peroxidation product, MDA, were significantly higher in the high BMI group than the low (normal) BMI group. As expected, high BMI was associated with an atherogenic lipid profile; however, it was also associated with fewer psychopathological symptoms. Multiple regression analysis found that MDA levels, the PANSS general psychopathology subscore, and triglyceride levels (all p < 0.05) were independent contributors to the BMI in patients. These results suggested that oxidative stress may play an important role in antipsychotic-induced weight gain. Further investigations using the longitudinal design in first-episode schizophrenia patients are needed to explore the beneficial effect of antioxidants on the abnormal lipid metabolism mediated by antipsychotic treatment.

Pretreatment With Risperidone Ameliorates Systemic LPS-Induced Oxidative Stress in the Cortex and Hippocampus

Risperidone (RIS), an atypical antipsychotic has been found to show anti-inflammatory effect against lipopolysaccharide (LPS)-induced inflammation. In vitro study has revealed that RIS inhibits the LPS-induced reactive oxygen species (ROS) formation. We investigated the antioxidant effects of RIS on LPS-induced oxidative stress markers in Swiss albino mice. Ten weeks old male Swiss albino mice (30 ± 2 g) were pretreated with either distilled water (control) or RIS (3 mg/kg) for 7 days. On day 8, animals were challenged with a single dose of LPS (0.8 mg/kg) while control animals received distilled water only. The animals were sacrificed after 24 h of LPS administration and tissue samples were collected. RIS administration significantly (p < 0.05) reduced the LPS-induced elevated levels of lipid peroxidation product malondialdehyde (MDA), advanced protein oxidation products, and nitric oxide (NO) in the cortex. Catalase (CAT) and superoxide dismutase (SOD) levels were also diminished while the level of glutathione (GSH) was enhanced. Hippocampus data showed that RIS significantly (p < 0.05) reduced the LPS-induced increased levels of MDA and NO, and SOD activity. Our results suggest that LPS-induced neuronal oxidative damage can be alleviated by the pretreatment with RIS and the effect is shown presumably by scavenging of the ROS by risperidone as an antioxidant.

Evaluation of antioxidant potencial of novel CaAl and NiAl layered double hydroxides loaded with olanzapine

Olanzapine (OLZ), is used in the treatment of bipolar disorder and schizophrenia, diseases that present oxidative stress in their physiopathology. It has low aqueous solubility, which may lead to low oral bioavailability. The search of new drug delivery systems (DDSs) that may increase dissolution rate of OLZ, associated with the investigation of the antioxidant potential of the loaded-systems become of major importance to understand improvement in bipolar disorder and schizophrenia therapy. Thus, this study aimed to evaluate the in vitro antioxidant potential of two different Layered Double Hydroxides (LDH) loaded with 5% of OLZ (CaAl and NiAl), by radical scavenging activity (2,2-Diphenyl-1-picrylhydrazyl and nitric oxid); radical cation scavenging activity (2,2'-azino-bis3-ethylbenzthiazoline-6-sulfonic acid ABTS) and evaluation of inhibition capacity of lipid peroxidation by thiobarbituric acid (TBARS). The results showed that both obtained LDH systems presented in vitro antioxidant capacity when associated with OLZ in all methods performed, and this activity is more pronounced with the systems containing OLZ compared to pure drug. The systems with CaAl was shown to have increased antioxidant potential, compared to NiAl, increasing the antioxidant activity up to 40,83%, 15,84% and 16,73%, as showed by the DPPH, nitric oxide and TBARS tests, respectively. The results revealed that the use of LDHs as a functional excipient may be promising in the pharmaceutical industry for bipolar disorder and schizophrenia therapy.

The Wnt Signaling Pathway Effector TCF7L2 Mediates Olanzapine-Induced Weight Gain and Insulin Resistance

Olanzapine is a widely used atypical antipsychotic medication for treatment of schizophrenia and is often associated with serious metabolic abnormalities including weight gain and impaired glucose tolerance. These metabolic side effects are severe clinical problems but the underpinning mechanism remains poorly understood. Recently, growing evidence suggests that Wnt signaling pathway has a critical role in the pathogenesis of schizophrenia and molecular cascades of antipsychotics action, of which Wnt signaling pathway key effector TCF7L2 is strongly associated with glucose homeostasis. In this study, we aim to explore the characteristics of metabolic disturbance induced by olanzapine and to elucidate the role of TCF7L2 in this process. C57BL/6 mice were subject to olanzapine (4 mg/kg/day), or olanzapine plus metformin (150 mg/kg/day), or saline, respectively, for 8 weeks. Metabolic indices and TCF7L2 expression levels in liver, skeletal muscle, adipose, and pancreatic tissues were closely monitored. Olanzapine challenge induced remarkably increased body weight, fasting insulin, homeostasis model assessment-insulin resistance index, and TCF7L2 protein expression in liver, skeletal muscle, and adipose tissues. Notably, these effects could be effectively ameliorated by metformin. In addition, we found that olanzapine-induced body weight gain and insulin resistance actively influence the expression of TCF7L2 in liver and skeletal muscle, and elevated level of insulin determines the increased expression of TCF7L2 in adipose tissue. Our results demonstrate that TCF7L2 participates in olanzapine-induced metabolic disturbance, which presents a novel mechanism for olanzapine-induced metabolic disturbance and a potential therapeutic target to prevent the associated metabolic side effects.

Oxidative stress in patients with refractory temporal lobe epilepsy and mesial temporal sclerosis: Possible association with major depressive disorder?

OBJECTIVE

The objective was to evaluate the genetic and biochemical profiles associated with oxidative stress (OS) in patients with temporal lobe epilepsy with mesial temporal sclerosis (TLE-MTS) and a healthy control group, and also to verify the possible existence of association between OS markers and psychiatric disorders (PD) in group with TLE-MTS.

METHODS

Forty-six patients with refractory TLE-MTS and 112 healthy controls were included. Psychiatric evaluation occurred through Diagnostical and Statistical Manual of Mental Disorders (DSM-5) criteria. A peripheral blood sample was collected for analysis of glutathione S-transferase (GST) T1/M1 polymorphisms and serum levels of malondialdehyde (MDA) and antioxidant capacity equivalent to the trolox (TEAC), serum markers of OS. Student's t-test, Fisher's exact test, Chi-square test, and Analysis of Variance (ANOVA) were used, with a significance level of P<0.05.

RESULTS

The PD were observed in 27 patients of the group with TLE-MTS (58.6%); major depressive disorder (MDD) was the most frequent. Serum levels of MDA (P<0.0001) and TEAC (P<0.0001) were higher in group with TLE-MTS. When patients with MDD were compared with patients without PD, significant differences were observed between MDA (P=0.002) and TEAC (P=0.003) serum levels. Patients with TLE-MTS and MDD presented higher levels when compared with patients with TLE-MTS without PD and with another PD except MDD.

CONCLUSIONS

The present study observed significantly higher serum levels of MDA and of TEAC in patients with refractory TLE-MTS in comparison with the control group. The MDD was observed as an important issue associated with higher OS levels in refractory TLE-MTS. Further studies are needed to investigate the association of OS, TLE-MTS, and PD.

Connecting Biology to Electronics: Molecular Communication via Redox Modality

Biology and electronics are both expert at for accessing, analyzing, and responding to information. Biology uses ions, small molecules, and macromolecules to receive, analyze, store, and transmit information, whereas electronic devices receive input in the form of electromagnetic radiation, process the information using electrons, and then transmit output as electromagnetic waves. Generating the capabilities to connect biology-electronic modalities offers exciting opportunities to shape the future of biosensors, point-of-care medicine, and wearable/implantable devices. Redox reactions offer unique opportunities for bio-device communication that spans the molecular modalities of biology and electrical modality of devices. Here, an approach to search for redox information through an interactive electrochemical probing that is analogous to sonar is adopted. The capabilities of this approach to access global chemical information as well as information of specific redox-active chemical entities are illustrated using recent examples. An example of the use of synthetic biology to recognize external molecular information, process this information through intracellular signal transduction pathways, and generate output responses that can be detected by electrical modalities is also provided. Finally, exciting results in the use of redox reactions to actuate biology are provided to illustrate that synthetic biology offers the potential to guide biological response through electrical cues.

Redox Probing for Chemical Information of Oxidative Stress

Oxidative stress is implicated in many diseases yet no simple, rapid, and robust measurement is available at the point-of-care to assist clinicians in detecting oxidative stress. Here, we report results from a discovery-based research approach in which a redox mediator is used to probe serum samples for chemical information relevant to oxidative stress. Specifically, we use an iridium salt (K2IrCl6) to probe serum for reducing activities that can transfer electrons to iridium and thus generate detectable optical and electrochemical signals. We show that this Ir-reducing assay can detect various biological reductants and is especially sensitive to glutathione (GSH) compared to alternative assays. We performed an initial clinical evaluation using serum from 10 people diagnosed with schizophrenia, a mental health disorder that is increasingly linked to oxidative stress. The measured Ir-reducing capacity was able to discriminate people with schizophrenia from healthy controls (p < 0.005), and correlations were observed between Ir-reducing capacity and independent measures of symptom severity.

Cardiovascular side effects of psychopharmacologic therapy

WHO defined in 1976 psychopharmaca as drugs affecting psychological functions, behaviour and self-perception. Psychopharmacology is the study of pharmacological agents that affect mental and emotional functions. Creative approach to psychopharmacotherapy reflects a transdisciplinary, integrative and person-centered psychiatry. Psychiatric disorders often occur in cardiac patients and can affect the clinical presentation and morbidity. Cardiovascular (CV) side effects (SE) caused by psychopharmaceutic agents require comprehensive attention. Therapeutic approach can increase placebo and decrease nocebo reactions. The main purpose of this review is to comprehend CV SE of psychotropic drugs (PD). Critical overview of CV SE of PD will be presented in this review. Search was directed but not limited to CV effects of psychopharmacological substances, namely antipsychotics, anxiolytics, hypnotics, sedatives, antidepressants and stimulants. Literature review was performed and data identified by searches of Medline and PubMed for period from 2004 to 2015. Only full articles and abstracts published in English were included. SE of PD are organized according to the following types of CV effects: cardiac and circulatory effects, abnormalities of cardiac repolarisation and arrhythmias and heart muscle disease. There is wide spectrum and various CV effects of PD. Results of this review are based on literature research. The reviewed data came largely from prevalence studies, case reports, and cross-sectional studies. Psychopharmacotherapy of psychiatric disorders is complex and when concomitantly present with CV disease, presentation of drug SEs can significantly contribute to illness course. Further development of creative psychopharmacotherapy is required to deal with CV effects of PD.

Levels of Red Blood Cell Fatty Acids in Patients With Psychosis, Their Unaffected Siblings, and Healthy Controls

BACKGROUND

Two recent meta-analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta-analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder.

METHODS

For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups.

RESULTS

Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings.

CONCLUSIONS

We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting stage of disorder, dietary patterns, medication use, and drug abuse are possible modifiers of FA, contributing to the heterogeneity in findings concerning FA in schizophrenia patients.

Oxidative stress in drug naïve first episode psychosis and antioxidant effects of risperidone

BACKGROUND

Schizophrenia is accompanied by increased lipid peroxidation and nitric oxide (NO) levels and by lowered antioxidant levels. However, the effect of antipsychotic agents on these processes remains unclear. The objective of this study is to determine the oxidative stress (OS) status in drug naïve first-episode psychotic patients (FEP) compared to healthy controls and to delineate the effects of risperidone on these biomarkers.

METHODS

51 drug naive FEP patients and 61 healthy controls were enrolled; FEP patients were reassessed 11 weeks after risperidone treatment. Three OS biomarkers, i.e. lipid hydroperoxides - LOOH, NO metabolites - NOx, and advanced oxidation protein products - AOPP, and two antioxidant biomarkers, i.e. total radical-trapping antioxidant parameter - TRAP, and paraoxonase 1 - PON1, were measured. The Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS) were used to measure symptoms severity.

RESULTS

Significantly lower PON1 activity and increased TRAP values were found in FEP patients. There were no significant associations between any of the OS/antioxidant biomarkers and clinical data. Risperidone treatment significantly increased PON1 activity and decreased LOOH levels. These effects of risperidone were not significantly associated with the clinical response and risperidone dosage.

DISCUSSION

Changes in antioxidant profile, but not in lipid or protein oxidation or increased NO production, were found in drug-naive FEP. Risperidone may have antioxidant effects by lowering lipid peroxidation and increasing the antioxidant defenses against lipid peroxidation related to PON1. None of the biomarkers predicted treatment outcome.

Lowered paraoxonase 1 (PON1) activity is associated with increased cytokine levels in drug naïve first episode psychosis

BACKGROUND

Activated immune-inflammatory pathways play an important role in the pathophysiology of schizophrenia. Paraoxonase 1 (PON1) activity is inversely associated with inflammatory responses in numerous clinical conditions. The aims of this study were to delineate serum arylesterase PON1 activity in drug-naïve first episode psychosis (FEP) patients and a healthy control group, and to assess whether there are inverse relationships between PON1 activity and cytokine levels.

METHODS

A total of 51 drug-naïve FEP patients and 61 healthy controls were enrolled in this study. Levels of interleukin (IL)-4, IL-10, IL-6, tumor necrosis factor (TNF)-α and activity of PON1 were quantified.

RESULTS

Compared to healthy controls, FEP patients showed lower serum PON1 activity and higher levels of IL-4, IL-10 and TNF-α. A significant inverse relationship between PON1 activity and IL-4, IL-6 and IL-10 levels was detected, but not for TNF-α. Subjects with very low PON1 activity (25th quartile) presented significantly higher levels of IL-6, IL-10 and IL-4 than those with higher PON1 activity (75th quartile).

CONCLUSION

The present study provides evidence that FEP is characterized by an inverse relationship between lowered activity of the anti-inflammatory/antioxidant enzyme PON1 and increased cytokine levels, including IL-6, IL-4 and IL-10. It is hypothesized that lowered PON1 activity may play a role in the immune-inflammatory response that accompanies FEP and that increased cytokine levels may further modulate PON1 activity.

Role of nitric oxide and related molecules in schizophrenia pathogenesis: biochemical, genetic and clinical aspects

Currently, schizophrenia is considered a multifactorial disease. Over the past 50 years, many investigators have considered the role of toxic free radicals in the etiology of schizophrenia. This is an area of active research which is still evolving. Here, we review the recent data and current concepts on the roles of nitric oxide (NO) and related molecules in the pathogenesis of schizophrenia. NO is involved in storage, uptake and release of mediators and neurotransmitters, including glutamate, acetylcholine, noradrenaline, GABA, taurine and glycine. In addition, NO diffuses across cell membranes and activates its own extrasynaptic receptors. Further, NO is involved in peroxidation and reactive oxidative stress. Investigations reveal significant disturbances in NO levels in the brain structures (cerebellum, hypothalamus, hippocampus, striatum) and fluids of subjects with schizophrenia. Given the roles of NO in central nervous system development, these changes may result in neurodevelopmental changes associated with schizophrenia. We describe here the recent literature on NOS gene polymorphisms on schizophrenia, which all point to consistent results. We also discuss how NO may be a new target for the therapy of mental disorders. Currently there have been 2 randomized double-blind placebo-controlled trials of L-lysine as an NOS inhibitor in the CNS.