Chronic Treatment with Nigella sativa Oil Exerts Antimanic Properties and Reduces Brain Inflammation in Rats

Nigella sativa (NS) is a native herb consumed habitually in several countries worldwide, possessing manifold therapeutic properties. Among them, anti-inflammatory features have been reported, presumably relating to mechanisms involved in the nuclear factor kappa-B pathway, among others. Given the observed association between neuroimmune factors and mental illness, the primary aim of the present study was to examine the effects of chronic NS use on manic-like behavior in rats, as well as analyze levels of brain inflammatory mediators following NS intake. Using male and female rats, baseline tests were performed; thereafter, rats were fed either regular food (control) or NS-containing food (treatment) for four weeks. Following intervention, behavioral tests were induced (an open field test, sucrose consumption test, three-chamber sociality test, and amphetamine-induced hyperactivity test). Subsequently, brain samples were extracted, and inflammatory mediators were evaluated, including interleukin-6, leukotriene B4, prostaglandin E2, tumor necrosis factor-α, and nuclear phosphorylated-p65. Our findings show NS to result in a marked antimanic-like effect, in tandem with a positive modulation of select inflammatory mediators among male and female rats. The findings reinforce the proposed therapeutic advantages relating to NS ingestion.

Factors Determining Plasticity of Responses to Drugs

The plasticity of responses to drugs is an ever-present confounding factor for all aspects of pharmacology, influencing drug discovery and development, clinical use and the expectations of the patient. As an introduction to this Special Issue of the journal IJMS on pharmacological plasticity, we address the various levels at which plasticity appears and how such variability can be controlled, describing the ways in which drug responses can be affected with examples. The various levels include the molecular structures of drugs and their receptors, expression of genes for drug receptors and enzymes involved in metabolism, plasticity of cells targeted by drugs, tissues and clinical variables affected by whole body processes, changes in geography and the environment, and the influence of time and duration of changes. The article provides a rarely considered bird’s eye view of the problem and is intended to emphasize the need for increased awareness of pharmacological plasticity and to encourage further debate.

Human macrophages stimulate expression of inflammatory mediators in adipocytes; effects of second-generation antipsychotics and glucocorticoids on cellular cross-talk

OBJECTIVE

Adipose tissue inflammation and distorted macrophage-adipocyte communication are positively associated with metabolic disturbances. Some pharmacological agents, such as second-generation antipsychotics (SGAs) and synthetic glucocorticoid (GC) dexamethasone, tend to induce adverse metabolic side effects and the underlying mechanisms are not fully understood. Our work aimed to study whether SGAs and dexamethasone affect macrophage phenotype and macrophage-adipocyte communication on gene expression level. We selected the model involving THP-1-derived macrophages, polarized into M0, M1, and M2 phenotypes, and primary human mature subcutaneous adipocytes.

METHODS

Abdominal subcutaneous adipose tissue needle biopsies were obtained from 6 healthy subjects (4F/2M; age: 22-64 yr; BMI: 21.7-27.6 kg/m2) followed by isolation of mature adipocytes. THP-1-human monocytic cell line was used for the study. THP-1 monocytes were differentiated and polarized into M0 (naïve), M1 (classically activated), and M2 (alternatively activated) macrophages. During and after polarization the macrophages were treated for 24 h without (control) or with therapeutic and supra-therapeutic concentrations of olanzapine (0.2 µM and 2.0 µM), aripiprazole (1.0 µM and 10 µM) and its active metabolite dehydroaripiprazole (0.4 µM and 4.0 µM). Isolated mature human adipocytes were co-incubated with THP-1-derived polarized macrophages pre-treated with SGAs after their polarization. Adipocytes and macrophages were collected before and after co-culture for mRNA expression analysis of genes involved in inflammation.

RESULTS

Co-incubation of mature human adipocytes with human macrophages, regardless of polarization, resulted in a marked induction of pro-inflammatory cytokines in adipocytes, including IL1B, IL6, TNFA, and IL10. Remarkably, it did not affect the expression of adipokines and genes involved in the regulation of energy, lipid, and glucose metabolism in adipocytes. Dexamethasone markedly reduced gene expression of pro-inflammatory cytokines in macrophages and prevented macrophage-induced inflammatory response in adipocytes. In contrast, SGAs did not affect macrophage-adipocyte communication and had a minute anti-inflammatory effect in macrophages at supra-therapeutic concentrations. Interestingly, the adipocytes co-incubated with M1 macrophages pre-treated with dexamethasone and SGAs particularly the supra-therapeutic concentration of olanzapine, reduced expression of LPL, LIPE, AKT1, and SLC2A4, suggesting that the expression of metabolic genes in adipocytes was dependent on the presence of pro-inflammatory M1 macrophages.

CONCLUSION

Together, these data suggest that macrophages induce expression of pro-inflammatory genes in human subcutaneous adipocytes without affecting the expression of adipokines or genes involved in energy regulation. Furthermore, our findings demonstrated that SGAs and dexamethasone had a mild effect on macrophage-adipocyte communication in M1 macrophage phenotype.

Interleukin-3, symptoms and cognitive deficits in first-episode drug-naïve and chronic medicated schizophrenia

Previous studies consistently showed that IL-3 signaling may be involved in the pathophysiology of schizophrenia. However, investigations of associations between IL-3 and the neurocognitive impairments are lacking, including the study of how this may vary with stage of illness. We recruited 45 first-episode drug-naïve (FE-Sz), 35 chronic medicated schizophrenia (Ch-Sz) and 40 healthy controls (HC) and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum IL-3. Altered serum IL-3 levels were found in both patient groups compared with HC group (both p < 0.001). There were significantly lower neurocognitive scores on the RBANS and nearly all of its five subscales, except for Visuospatial/Constructional index in both FE-Sz and Ch-Sz patients vs healthy controls. Moreover, a significant reduction in Immediate memory index (p = 0.021) and a trend-level reduction in RBANS total score (p = 0.094) in Ch-Sz than FE-Sz patients. Interestingly, there was a significant negative correlation between IL-3 and the Immediate memory index only in Ch-Sz patients (p = 0.03). Our findings showed that neurocognitive impairments present in schizophrenia emerge during the first episode with further diminished functioning with disease progression, and IL-3 may be involved in the immediate memory deficits in the chronic phase of schizophrenia.

Interleukin-6 in Schizophrenia-Is There a Therapeutic Relevance?

Renewing interest in immune aspects of schizophrenia and new findings about the brain-fat axis encourage us to discuss the possible role of interleukin-6 (IL-6) in schizophrenia. Previously, it was suggested that a primary alteration of the innate immune system may be relevant in schizophrenia. Functional dichotomy of IL-6 suggests that this chemical messenger may be responsible for regulating the balance between pro- and anti-inflammatory responses, with tissue-specific properties at the periphery and in the central nervous system. Specific phase of this chronic and deteriorating disorder must be considered, which can involve IL-6 in acute or possible chronic inflammation and/or autoimmunity. We give an overview of IL-6 role in the onset and progression of this disorder, also considering cognitive impairment and metabolic changes in patients with schizophrenia. Data suggest that decreased serum level of IL-6 following antipsychotic therapy could be predisposing factor for the development of obesity and obesity-related metabolic disorders in schizophrenia. As we reviewed, the IL-6 plays significant role in disease genesis and progression, so the use of specific inhibitors may not only be beneficial for exacerbation and alleviation of positive symptoms, but may attenuate cognitive impairment in patients with schizophrenia.

Changes in the cytokine profile in first-episode, drug-naïve patients with psychosis after short-term antipsychotic treatment

An increasing body of evidence suggests that antipsychotic medication can cause immunological changes that could be attributed to the amelioration of psychotic symptoms or the metabolic side effects of the drugs. So far, the results of the studies remain controversial. Our aim was to compare the levels of interleukin (IL) IL-2, IL-6 and transforming growth factor-β2 (TGF-β2) in drug-naïve, first-episode patients with psychosis before and after six weeks of antipsychotic medication. Thirty-nine first-episode patients with psychosis were enrolled in the study. Serum levels of IL-2, IL-6 and TGF-β2 were measured by enzyme linked immunosorbent assay (ELISA) before and six weeks after the initiation of antipsychotics. In addition, clinical psychopathology was assessed using Positive and Negative Syndrome Scale (PANSS) before and after treatment. Serum levels of IL-2 were significantly increased six weeks after the initiation of antipsychotic treatment (p <0.001) while TGF-β2 levels were decreased (p <0.001). IL-6 levels were overall increased (p <0.004), but this occurred in a non-linear way. These findings, although preliminary, provide further evidence that antipsychotic treatment in patients with psychosis may be correlated with immunological changes but further research is needed.

Inflammatory monocyte gene expression: trait or state marker in bipolar disorder?

Background

This study aimed to examine whether inflammatory gene expression was a trait or a state marker in patients with bipolar disorder (BD).

Methods

69 healthy controls (HC), 82 euthymic BD patients and 8 BD patients with a mood episode (7 depressed, 1 manic) were included from the MOODINFLAME study. Six of the eight patients who had a mood episode were also investigated when they were euthymic (6 of the 82 euthymic patients). Of these participants the expression of 35 inflammatory genes was determined in monocytes using quantitative-polymerase chain reaction, of which a total gene expression score was calculated as well as a gene expression score per sub-cluster.

Results

There were no significant differences in inflammatory monocyte gene expression between healthy controls and euthymic patients. Patients experiencing a mood episode, however, had a significantly higher total gene expression score (10.63 ± 2.58) compared to healthy controls (p = .004) and euthymic patients (p = .009), as well as when compared to their own scores when they were euthymic (p = .02). This applied in particular for the sub-cluster 1 gene expression score, but not for the sub-cluster 2 gene expression score.

Conclusions

Our study indicates that in BD inflammatory monocyte, gene expression is especially elevated while in a mood episode compared to being euthymic.

Regulation of interleukin-6 and leptin in schizophrenia patients: a preliminary analysis

Objective

Immune-inflammatory mediators play a pivotal role in brain signaling and have been increasingly associated with the pathophysiology of schizophrenia. Many studies have indicated an increased level of immune-inflammatory interleukin-6 (IL-6) in schizophrenia. IL-6 is a well-known chief stimulator of inflammation. Of late leptin has also been implicated in the inflammatory pathway of schizophrenia. In this study we measured and compared serum levels of IL-6 and leptin in patients with schizophrenia to healthy controls, and investigated the relationship between IL-6 and leptin.

Methods

Serum IL-6 and leptin were determined in 20 patients diagnosed with schizophrenia and in 19 healthy controls matched by gender, age and body mass index (BMI) using commercial Bioplex assays.

Results

Using Mann-Whitney U-test, significantly increased IL-6 levels were found in the patients but there was no significant difference in leptin levels though a trend towards higher leptin was observed in the patients. Spearman correlations did not show any correlation between IL-6 and clinical variables except antipsychotic dosage. Leptin significantly correlated with gender and BMI. A large effect size correlation was observed between IL-6 and leptin in the patients but not in the controls. Multiple regression analysis performed on patients, after adjusting for gender and BMI, revealed there was no significant association between IL-6 and leptin.

Conclusion

IL-6 and leptin levels may reflect the chronic inflammatory state associated with schizophrenia but further evaluation is required. Also, it is important to consider the confounding effects of obesity in any examination of relationships between groups with regard to cytokines and adipokines.

Therapeutic effect of aripiprazole in chronic schizophrenia is accompanied by anti-inflammatory activity

BACKGROUND

Weight gain and metabolic abnormalities occur in chronic schizophrenia patients treated with atypical antipsychotics. The purpose of the study was to evaluate changes in serum levels of C-reactive protein (CRP), insulin and cytokines (IL-6, TNF-α, IL-1β, IFN-γ, sTNF-R1, IL-12, IL-23, IL-1Ra, TGF-β1, IL-4, and IL-10) after switching to aripiprazole.

METHODS

Cytokine, hsCRP and insulin measurements were performed in patients (n=17) on day 0 and day 28 of the study using standard ELISA assays. The psychopathological status was assessed using PANSS. WC and BMI were measured and calculated, respectively.

RESULTS

We observed high clinical efficacy in aripiprazole linked to a 2.7% weight loss. There were statistically significant reductions in PANSS scores and body parameters (p<0.001). After 28 days we detected a significant reduction in hsCRP (p<0.001), insulin (p<0.001), IL-1β, IL-6, TNF-α, sTNF-R1, IL-12, IL-23, IL-1Ra, TGF-β1, IL-4 (p<0.001), IFN-γ (p<0.05) and a significant elevation of IL-10 (p<0.001). There was a significant negative correlation between IL-10 levels and PANSS positive, negative and total scores after the study (p=0.022, p=0.003, p=0.008, respectively).

CONCLUSIONS

Aripiprazole limits inflammatory processes by enhancing anti-inflammatory signaling. Aripiprazole also reduces the risk of metabolic abnormalities.

Antipsychotics' effects on blood levels of cytokines in schizophrenia: a meta-analysis

OBJECTIVES

Evidence-based medicine suggests that schizophrenia is associated with an inflammatory syndrome, but the extent to which this syndrome is normalized by antipsychotic treatment has yet to be determined.

METHODS

A systematic quantitative review of the effects of antipsychotics on peripheral cytokine levels in schizophrenia was performed, using follow-up studies providing in vivo cytokine assessments before and after treatment.

RESULTS

We retrieved 23 studies (total of 762 subjects) which showed that antipsychotic treatment significantly increases plasma levels of soluble interleukin-2 receptor and reduces the plasma levels of interleukin-1β and interferon-γ.

CONCLUSIONS

These results show that antipsychotics produce anti-inflammatory effects in schizophrenia.