Beneficial effect of aspirin against interferon-α-2b-induced depressive behavior in Sprague Dawley rats

Effect of Aspirin vs Placebo on the Prevention of Depression in Older People: A Randomized Clinical Trial

IMPORTANCE

Depression is associated with increased inflammation, which may precede its onset, especially in older people. Some preclinical data suggest potential antidepressant effects of aspirin, supported by limited observational data suggesting lower rates of depression in individuals treated with aspirin. There currently appears to be no evidence-based pharmacotherapies for the primary prevention of depression.

OBJECTIVE

To determine whether low-dose aspirin (100 mg) reduces the risk of depression in healthy older adults.

DESIGN, SETTING, AND PARTICIPANTS

This double-blinded, placebo-controlled randomized clinical trial was a substudy of the Aspirin in Reducing Events in the Elderly (ASPREE) trial, which examined if aspirin increased healthy life span, defined as survival free of dementia and disability. The prespecified secondary outcome was depression. Individuals of all races/ethnicities older than 70 years in Australia, as well as white individuals older than 70 years and black and Hispanic individuals older than 65 years in the United States, were included.

INTERVENTIONS

Participants were randomized to aspirin (100 mg daily) or placebo, with a median (interquartile range) follow-up of 4.7 (3.5-5.6) years.

MAIN OUTCOMES AND MEASURES

The primary outcome was a proxy measure of major depressive disorder defined as a score of 8 or more on the Center for Epidemiologic Studies Depression 10-item (CES-D-10) scale.

RESULTS

Of the 19 114 participants enrolled in the trial, 9525 received aspirin and 9589 received a placebo. The mean (SD) age was 75.2 (4.0) years in the aspirin group and 75.1 (4.5) years in the placebo group; 9531 (56.4%) were women. Participants' demographics and clinical characteristics at baseline were similar between groups. A total of 79 886 annual CES-D-10 measurements were taken, with a mean of 4.2 measurements per participant. There were no significant differences at annual visits in the proportions of CES-D-10 scores of 8 or more between the aspirin and placebo groups. The incidence rate of new CES-D-10 scores of 8 or more was 70.4 events per 1000 person-years in the aspirin group and 69.1 in the placebo group (hazard ratio, 1.02 [95% CI, 0.96-1.08]; P = .54).

CONCLUSIONS AND RELEVANCE

Low-dose aspirin did not prevent depression in this large-scale study of otherwise healthy older adults.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01038583.

Do We Build Similar Molecules for Comorbid Diseases? Tevarud in Drug Design, an Analysis for Depression and Inflammation

Tevarud designates two poets coincidently writing a same verse in the Ottoman Divan literature. This study aims to analyze the structural similarity of molecules independently designed for inflammation and depression to determine if coincidentally we are building similar molecules for comorbid diseases. For this purpose, a molecule library was first constituted with structures that were developed as anti-inflammatory (AI) and antidepressant (AD) agents these last decades. Then, the similarity of the structures was determined by calculating the Tanimoto and Cosine similarity coefficients for each AD/AI pair. The highest scores were obtained for two theophylline derivatives: AD17 (for which some AI activity was found to be mentioned) and AI42. The study also pointed out the similarity of some AD coumarins with some AI flavonoids interestingly found to be highly similar to some AI coumarins and AD flavonoids, respectively. Thus, our investigation demonstrated that structures independently developed as AD and AI derivatives can present extremely high structural similarity, a finding that can suggest mechanistic interconnection for these comorbid diseases and also guide for the design of novel bioactive compounds.

Celecoxib, a cyclooxygenase-2 inhibitor, offers chemoprevention against reproductive and neurobehavioural abnormalities induced by atrazine in male Wistar rats

The cyclooxygenase-2/prostanoid pathway (COX-2) serves as a potential therapeutic target in various pathological conditions. Thus, the modulatory effect of celecoxib (CXB), a COX-2 inhibitor, in atrazine-induced toxicity was investigated. Five groups (n = 6 rats per group) of adult male Wistar rats received corn oil (2 ml/kg), atrazine (ATZ, 300 mg/kg) and CXB (5.7 mg/kg) respectively and their combinations via the oral route. Results obtained showed reduced (p < 0.05) sperm motility (25.8%) and counts (27.6%), testosterone (29.9%), luteinizing (33%) and follicle stimulating hormones (78.7%) plus elevated total cholesterol (112.3%), triglyceride (115.7%), malondialdehyde levels respectively in ATZ-treated rats. Similarly, ATZ administration causes reduced locomotion (33.6%), spontaneous motor activity (46.6%) and catalepsy effects (157.3%) respectively. However, CXB divided doses moderately reverse reproductive abnormalities, modulate neurobehavioural deficits and slightly preserved COX-2 elevation following ATZ intoxication. Furthermore, histopathology of testis shows improvement in treated rats. Overall, our data suggest chemopreventive actions via pharmacological inhibition of COX-2 activity during ATZ toxicity.

Protective effect of aspirin treatment on mouse behavior in the acute phase of experimental infection with Trypanosoma cruzi

Chagas disease is a potentially fatal disease caused by the parasite Trypanosoma cruzi, which can in some cases affect the central nervous system. The objective was to evaluate the effect of aspirin (ASA) in the behavior of mice infected with T. cruzi during the acute phase. This was an experimental study with random assignation. Twenty four BALB/c mice were divided into four groups of six animals each as follows: only ASA (OA), ASA before infection (BI), ASA after infection (AI) and only infection (OI). The strain used for infection was M/HOM/Bra/53/Y. An ASA dose of 100 mg/kg per day was administered 72 h before infection to BI group and the same dose 48 h after infection to AI group. Mice behavior in the open field test, mortality, and brain histopathology was evaluated. Data were analyzed using ANOVA, chi square test, and Kaplan-Meier with long-rank for survival analysis. In the open field test, the OA group has similar results with the BI group, in the variables of immobility and escape. Also, the OA group displayed significantly higher rates of micturition (p < 0.001) and defecation (p < 0.001) compared to infected groups. Mortality was higher in BI group (p = 0.02). The presence of T. cruzi amastigotes were higher in brain tissues of the AI and OI groups (p = 0.008). In conclusion, the administration of ASA before infection seemed to prevent behavioral changes induced by the acute infection, but it led to accelerated mortality. The study highlighted the potential importance of the pathways inhibited by ASA in the early hours of acute infection with T. cruzi.

Visceral Inflammation and Immune Activation Stress the Brain

Stress refers to a dynamic process in which the homeostasis of an organism is challenged, the outcome depending on the type, severity, and duration of stressors involved, the stress responses triggered, and the stress resilience of the organism. Importantly, the relationship between stress and the immune system is bidirectional, as not only stressors have an impact on immune function, but alterations in immune function themselves can elicit stress responses. Such bidirectional interactions have been prominently identified to occur in the gastrointestinal tract in which there is a close cross-talk between the gut microbiota and the local immune system, governed by the permeability of the intestinal mucosa. External stressors disturb the homeostasis between microbiota and gut, these disturbances being signaled to the brain via multiple communication pathways constituting the gut-brain axis, ultimately eliciting stress responses and perturbations of brain function. In view of these relationships, the present article sets out to highlight some of the interactions between peripheral immune activation, especially in the visceral system, and brain function, behavior, and stress coping. These issues are exemplified by the way through which the intestinal microbiota as well as microbe-associated molecular patterns including lipopolysaccharide communicate with the immune system and brain, and the mechanisms whereby overt inflammation in the GI tract impacts on emotional-affective behavior, pain sensitivity, and stress coping. The interactions between the peripheral immune system and the brain take place along the gut-brain axis, the major communication pathways of which comprise microbial metabolites, gut hormones, immune mediators, and sensory neurons. Through these signaling systems, several transmitter and neuropeptide systems within the brain are altered under conditions of peripheral immune stress, enabling adaptive processes related to stress coping and resilience to take place. These aspects of the impact of immune stress on molecular and behavioral processes in the brain have a bearing on several disturbances of mental health and highlight novel opportunities of therapeutic intervention.

Pharmacotherapy in Generalized Anxiety Disorder: Novel Experimental Medicine Models and Emerging Drug Targets

Many pharmacological and psychological approaches have been found efficacious in patients with generalized anxiety disorder (GAD), but many treatment-seeking patients will not respond and others will relapse despite continuing with interventions that initially had beneficial effects. Other patients will respond but then stop treatment early because of untoward effects such as sexual dysfunction, drowsiness, and weight gain. There is much scope for the development of novel approaches that could have greater overall effectiveness or acceptability than currently available interventions or that have particular effectiveness in specific clinical subgroups. 'Experimental medicine' studies in healthy volunteers model disease states and represent a proof-of-concept approach for the development of novel therapeutic interventions: they determine whether to proceed to pivotal efficacy studies and so can reduce delays in translating innovations into clinical practice. Investigations in healthy volunteers challenged with the inhalation of air 'enriched' with 7.5% carbon dioxide (CO₂) indicate this technique provides a validated and robust experimental medicine model, mirroring the subjective, autonomic, and cognitive features of GAD. The anxiety response during CO₂ challenge probably involves both central noradrenergic neurotransmission and effects on acid-base sensitive receptors and so may stimulate development of novel agents targeted at central chemosensors. Increasing awareness of the potential role of altered cytokine balance in anxiety and the interplay of cytokines with monoaminergic mechanisms may also encourage the investigation of novel agents with modulating effects on immunological profiles. Although seemingly disparate, these two approaches to treatment development may pivot on a shared mechanism in exerting anxiolytic-like effects through pharmacological effects on acid-sensing ion channels.