Classics in Chemical Neuroscience: Amitriptyline

Amitriptyline nanoparticle repositioning prolongs the anti-allodynic effect of enhanced microglia targeting

Aim: Amitriptyline (AMI) has been used to treat neuropathic pain. However, the clinical outcomes remain unsatisfactory, presumably due to a limited understanding of the underlying molecular mechanisms. Here, we investigated a drug repositioning strategy using a low-dose of AMI encapsulated in poly (D, L lactic-co-glycolic acid) (PLGA) nanoparticles (AMI NPs) for neuropathic pain, since PLGA nanoparticles are known to enhance delivery to microglia.Methods: We evaluated the anti-allodynic effects of AMI and AMI NPs on neuropathic pain by assessing behaviors and inflammatory responses in a rat model of spinal nerve ligation (SNL). While the anti-allodynic effect of AMI (30 μg) drug injection on SNL-induced neuropathic pain persisted for 12 h, AMI NPs significantly alleviated mechanical allodynia for 3 days.Results: Histological and cytokine analyses showed AMI NPs facilitated the reduction of microglial activation and pro-inflammatory mediators in the spinal dorsal horn. This study suggests that AMI NPs can provide a sustained anti-allodynic effect by enhancing the targeting of microglia and regulating the release of pro-inflammatory cytokines from activated microglia.Conclusion: Our findings suggest that the use of microglial-targeted NPs continuously releasing AMI (2 μg) as a drug repositioning strategy offers long-term anti-allodynic effects.

FDA-approved drugs containing dimethylamine pharmacophore: a review of the last 50 years

Dimethylamine (DMA) derivatives represent a promising class of compounds with significant potential in the field of medicinal chemistry. DMA derivatives exhibit a diverse range of pharmacological activities, including antimicrobial, antihistaminic, anticancer, and analgesic properties. Their unique chemical structure allows for the modulation of various biological targets, making them valuable candidates for the treatment of numerous diseases. Synthetic strategies for the preparation of DMA derivatives vary depending on the desired biological activity and target molecule. Common synthetic routes involve the modification of the DMA scaffold through functional group manipulation, scaffold hopping, or combinatorial chemistry approaches. Therapeutically, DMA derivatives have shown promise in the treatment of infectious diseases, especially bacterial infections. Additionally, by focusing on particular biochemical pathways involved in tumor growth and metastasis, DMA-based drugs have shown anticancer activity. In addition to their direct pharmacological effects, DMA derivatives can serve as valuable tools in drug delivery systems, prodrug design, and molecular imaging techniques, enhancing their utility in medicinal chemistry research. Overall, DMA derivatives represent a versatile class of compounds with immense potential in medicinal chemistry. Further research and development efforts are warranted to explore their full therapeutic capabilities and optimize their clinical utility in the treatment of various diseases. This article outlines the pharmacological properties, synthetic strategies, and therapeutic applications of DMA derivatives of FDA approved drugs, highlighting their importance in drug discovery and development.

German Society of Neurology guidelines for the diagnosis and treatment of cognitive impairment and affective disorders in people with Parkinson's disease: new spotlights on diagnostic procedures and non-pharmacological interventions

BACKGROUND AND OBJECTIVE

Cognitive impairment and dementia as well as affective disorders are common and debilitating syndromes that develop in people with Parkinson's disease (PwPD). The authors summarized recommendations for the 2023 updated German guidelines on "Parkinson's disease" from the German Neurological Society (DGN), focusing on the diagnosis and treatment of these disorders.

METHODS

The recommendations were based on literature reviews, other relevant guidelines, and expert opinions.

RESULTS

Measurements to assess cognitive and affective states were reviewed for psychometric properties, use in routine clinical practice, and availability in German. To improve mild cognitive impairment, cognitive training and physical aerobic training are recommended. To treat Parkinson's disease (PD)-related dementia, cognitive stimulation (as a non-pharmacological intervention) and acetylcholinesterase inhibitors (AChEIs, i.e., rivastigmine) are recommended. Cognitive behavioral therapy is recommended to treat depression, anxiety, and fear of progression. Physical interventions are recommended to treat depression, fatigue, and apathy. Optimized dopaminergic treatment is the first-line pharmacological strategy recommended to manage depression, apathy, anhedonia, fatigue, and mood swings. Major depression can be additionally treated using venlafaxine or desipramine, while moderate depression can be treated pharmacologically according to its clinical phenotype (psychomotor retardation or agitation) and comorbidities (e.g., sleep disturbances, pain). Venlafaxine and nortriptyline can be used to treat anhedonia, while citalopram can be used for anxiety.

CONCLUSIONS

In addition to the updated pharmacological treatment options, new insights into recommendations for standardized diagnostics and non-pharmacological interventions were provided for the German health care system. However, more studies are needed to explore the full potential of non-pharmacological interventions to treat and prevent cognitive impairment and affective disorders.

Nanocarrier drug delivery system: promising platform for targeted depression therapy

Depression is a chronic mental disorder characterized by persistent low mood and loss of interest. Treatments for depression are varied but may not be sufficient cure. Drug-based treatment regimens have drawbacks such as slow onset of action, low bioavailability, and drug side effects. Nanocarrier Drug Delivery Systems (NDDS) has received increasing attention for brain drug delivery since it assists the drug through the blood-brain barrier and improves bioavailability, which may be beneficial for treating depression. Due to the particle size and physicochemical properties of nanocarriers, it presents a promise to improve the stability and solubility of antidepressants, thereby enhancing the drug concentration. Moreover, ligand-modified nanocarriers can be taken as a target direct medicines release system and reduce drug side effects. The purpose of the present review is to provide an up-to-date understanding of the Nanocarrier drug delivery system and relevant antidepressants in different routes of ingestion, to lay a foundation for the treatment of patients with depression.

Investigating the synergistic effects of amitriptyline and H. pylori eradication on depressive-like behaviors and inflammatory cytokines in mice

BACKGROUND

Recent research has highlighted the potential role of Helicobacter pylori in the pathogenesis of psychiatric disorders. This study aimed to evaluate the potential synergistic effects of an antidepressant drug and H. pylori eradication therapy in a mouse model.

METHODS

Male C57BL/6 mice were divided into four groups: control, H. pylori infection, antidepressant treatment, and combined treatment. H. pylori infection was induced by oral gavage with a clinically relevant strain, and the antidepressant drug was administered via intraperitoneal injections. Behavioral tests including the forced swim test, sucrose preference test, and open field test were conducted to assess depressive-like behaviors and locomotor activity.

RESULTS

The study demonstrated that H. pylori infection induced depressive-like behaviors in mice, as evidenced by increased immobility time in the forced swim test and reduced sucrose preference. Antidepressant treatment alone partially ameliorated these behavioral changes. Strikingly, the combined treatment of the antidepressant drug and H. pylori eradication therapy led to a significantly greater reduction in depressive-like behaviors compared to either treatment alone. Furthermore, the combined treatment group exhibited increased locomotor activity in the open field test, suggesting a potential improvement in overall psychomotor functioning. ELISA assays revealed alterations in inflammatory cytokines in the H. pylori-infected mice, which were partially attenuated by the combined treatment.

CONCLUSION

The study provides novel evidence for the potential synergistic effects of an antidepressant drug and H. pylori eradication therapy in alleviating depressive-like behaviors in a mouse model.

Identification of an Epoxide Metabolite of Amitriptyline In Vitro and In Vivo

Amitriptyline (ATL), a tricyclic antidepressant, has been reported to cause various adverse effects, particularly hepatotoxicity. The mechanisms of ATL-induced hepatotoxicity remain unknown. The study was performed to identify the olefin epoxidation metabolite of ATL and determine the possible toxicity mechanism. Two glutathione (GSH) conjugates (M1 and M2) and two N-acetylcysteine (NAC) conjugates (M3 and M4) were detected in rat liver microsomal incubations supplemented with GSH and NAC, respectively. Moreover, M1/M2 and M3/M4 were respectively found in ATL-treated rat primary hepatocytes and in bile and urine of rats given ATL. Recombinant P450 enzyme incubations demonstrated that CYP3A4 was the primary enzyme involved in the olefin epoxidation of ATL. Treatment of hepatocytes with ATL resulted in significant cell death. Inhibition of CYP3A attenuated the susceptibility to the observed cytotoxicity of ATL. The metabolic activation of ATL most likely participates in the cytotoxicity of ATL.

Refining the correction factor for a better monitoring of antidepressant use by wastewater-based epidemiology: A case study of amitriptyline

Wastewater-based epidemiology (WBE) is proposed as a cost-effective approach to objectively monitor the antidepressant use but it requires more accurate correction factors (CF) than what had been used in previous studies. Amitriptyline is a popular prescription medicine for treating depression and nerve pain, which could be prone to misuse and need monitoring. The CF of amitriptyline employed in previous WBE studies varied from 10 to 100, leading to substantial disparities between WBE estimates and expected mass of antidepressants in wastewater. Hence, this study aimed to take amitriptyline as a case study and refine the CF by correlating mass loads measured in wastewater from 12.2 million inhabitants collected during the 2016 Census with corresponding annual sales data. The triangulation of WBE data and sales data resulted in a newly-derived CF of 7, which is significantly different from the CF values used in previous studies. The newly derived CF was applied to a secondary, multi-year (2017 to 2020) WBE dataset for validation against sales data in the same period, demonstrating the estimated amitriptyline use (380 ± 320 mg/day/1000 inhabitants) is consistent with sales data (450 ± 190 mg/day/1000 inhabitants). When we applied the new CF to previous studies, the wastewater consumption loads matched better to prescription data than previous WBE estimations. The refined CF of amitriptyline can be used in future WBE studies to improve the accuracy of the consumption estimates.

Clinical effects of combined use of carbamazepine and amitriptyline in the treatment of diabetic neuropathy with concurrent diabetic foot

OBJECTIVE

This study aims to analyze the clinical effects of combining carbamazepine and amitriptyline in the treatment of diabetic neuropathy with concurrent diabetic foot.

METHODS

A total of 120 diabetic neuropathy patients treated at our hospital from June 2022 to November 2023 were included in the study. Patients meeting the inclusion criteria were registered, and their basic data were collected. The patients were randomly divided into two groups: the control group treated with amitriptyline and the study group treated with a combination of carbamazepine and amitriptyline.

RESULTS

The study group demonstrated significantly better clinical efficacy compared to the control group (p < 0.05). There were no significant differences in psychological status and pain perception before treatment between the two groups (p > 0.05). However, post-treatment, the study group showed improved psychological status, reduced pain perception, and overall better quality of life in both physiological and psychological dimensions compared to the control group (p < 0.05).

CONCLUSION

The combined use of carbamazepine and amitriptyline in the treatment of diabetic neuropathy with concurrent diabetic foot yields positive clinical outcomes. It effectively alleviates symptoms, improves psychological well-being, reduces pain sensation, and enhances overall quality of life. These findings can guide physicians in adopting a more evidence-based treatment approach and provide patients with more effective individualized treatment strategies.

An Overview of Degradation Strategies for Amitriptyline

Antidepressant drugs play a crucial role in the treatment of mental health disorders, but their efficacy and safety can be compromised by drug degradation. Recent reports point to several drugs found in concentrations ranging from the limit of detection (LOD) to hundreds of ng/L in wastewater plants around the globe; hence, antidepressants can be considered emerging pollutants with potential consequences for human health and wellbeing. Understanding and implementing effective degradation strategies are essential not only to ensure the stability and potency of these medications but also for their safe disposal in line with current environment remediation goals. This review provides an overview of degradation pathways for amitriptyline, a typical tricyclic antidepressant drug, by exploring chemical routes such as oxidation, hydrolysis, and photodegradation. Connex issues such as stability-enhancing approaches through formulation and packaging considerations, regulatory guidelines, and quality control measures are also briefly noted. Specific case studies of amitriptyline degradation pathways forecast the future perspectives and challenges in this field, helping researchers and pharmaceutical manufacturers to provide guidelines for the most effective degradation pathways employed for minimal environmental impact.

Core-Labeled Reverse Micelle-Based Supramolecular Solvents for Assisted Quick and Sensitive Determination of Amitriptyline in Wastewater

In recent years, the issue of pharmaceutical contaminants in water bodies has emerged as a significant environmental concern owing to the potential negative impacts on both aquatic ecosystems and human health. Consequently, the development of efficient and eco-friendly methods for their determination and removal is of paramount importance. In this context, the development of a surfactant ensemble sensor has been explored for hard-to-sense amphiphilic drug, i.e., amitriptyline. Herein, a pyrene-based amphiphile chemoreceptor was synthesized and characterized through various spectroscopic techniques such as 1H, 13C NMR, single-crystal XRD, FTIR, and ES-mass spectrometry. Then, dodecanoic acid (DA) and a pyrene-based receptor in a THF/water solvent system were used to generate reverse micelle-based self-aggregates of SUPRAS (SUPRAmolecular Solvent). The structural aspects, such as morphology and size, along with the stability of the SUPRAS aggregates were unfolded through spectroscopic and microscopic insights. The present investigation describes a synergistic approach that combines the unique properties of premicellar concentration of supramolecular solvent with the promising potential of pyrene-based receptor for enhanced amitriptyline extraction with simultaneous determination from water (LOD = 12 nM). To evaluate the effectiveness of the developed aggregates in real-world scenarios, experiments were conducted to determine the sensing efficiency among various pharmaceutical pollutants commonly found in water sources. The results reveal that the synergistic nanoensemble exhibits remarkable sensing ability, toward the amitriptyline (AMT) drug outperforming conventional methods.

Assessing Dose- and Sex-Dependent Antinociceptive Effects of Cannabidiol and Amitriptyline, Alone and in Combination, and Exploring Mechanism of Action Involving Serotonin 1A Receptors

Inflammatory pain is caused by tissue hypersensitization and is a component of rheumatic diseases, frequently causing chronic pain. Current guidelines use a multimodal approach to pain and sociocultural changes have renewed interest in cannabinoid use, particularly cannabidiol (CBD), for pain. The tricyclic antidepressant amitriptyline (AT) is approved for use in pain-related syndromes, alone and within a multimodal approach. Therefore, we investigated sex- and dose-dependent effects of CBD and AT antinociception in the 2.5% formalin inflammatory pain model. Male and female C57BL/6J mice were pretreated with either vehicle, CBD (0.3-100 mg/kg), or AT (0.1-30 mg/kg) prior to formalin testing. In the acute phase, CBD induced antinociception after administration of 30-100 mg/kg in males and 100 mg/kg in females and in the inflammatory phase at doses of 2.5-100 mg/kg in males and 10-100 mg/kg in females. In the acute phase, AT induced antinociception at 10 mg/kg for all mice, and at 0.3 mg/kg in males and 3 mg/kg in female mice in the inflammatory phase. Combining the calculated median effective doses of CBD and AT produced additive effects for all mice in the acute phase and for males only in the inflammatory phase. Use of selective serotonin 1A receptor antagonist N-[2-[4-(2-methoxyphenyl)-1 piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide (WAY-100635) maleate (0.1 mg/kg) before co-administration of CBD and AT reversed antinociception in the acute and partially reversed antinociception in the inflammatory phase. Administration of AT was found to enhance cannabinoid receptor type 1mRNA expression only in female mice. These results suggest a role for serotonin and sex in mediating cannabidiol and amitriptyline-induced antinociception in inflammatory pain. SIGNIFICANCE STATEMENT: Inflammatory pain is an important component of both acute and chronic pain. We have found that cannabidiol (CBD) and amitriptyline (AT) show dose-dependent, and that AT additionally shows sex-dependent, antinociceptive effects in an inflammatory pain model. Additionally, the combination of CBD and AT was found to have enhanced antinociceptive effects that is partially reliant of serotonin 1A receptors and supports the use of CBD within a multimodal approach to pain.

Dysorgasmia in women: Case report and preliminary assessment guide

Dysorgasmia in women is an infrequent reason for consulting a clinician. In this article, the authors describe the case of a woman with right-sided pelvic pain immediately after orgasm. Dysorgasmia is likely to negatively impact sexual health but is rarely discussed in medical literature. Furthermore, assessment and treatment guidelines for clinicians are currently lacking. Therefore, the authors conducted a literature review and created a preliminary assessment guide, considering both medical and gray literature. A brief flowchart was developed which can facilitate the assessment of dysorgasmia in women for clinicians and improve the quality of care for patients. Further research on the etiology and pathophysiology of dysorgasmia in women is warranted, as is a more proactive attitude of clinicians to discuss sexual health. More guidance on diagnosis and treatment is needed.

Stereoselective Unsymmetrical 1,1-Diborylation of Alkynes with a Neutral sp2 -sp3 Diboron Reagent

The incorporation of two distinct boryl groups at the same carbon center in organic molecules has attracted growing research interest due to its potential for facilitating controlled, precise synthesis through stepwise dual carbon-boron bond transformations. Here we report a method to access unsymmetrical 1,1-diborylalkene (UDBA) stereoselectively via the reaction of readily available alkynes with a neutral sp2 -sp3 diboron reagent (NHC)BH2 -Bpin (NHC=N-heterocyclic carbene). Attributing to the chemically easily distinguishable nature of the sp2 and sp3 boryl moieties, controllable stepwise derivatization of the resultant UDBAs is realized. This process leads to various multifunctionalized olefins and organoborons, such as acylboranes, which are difficult to prepare by other methods.

Growing Utilization of Radical Chemistry in the Synthesis of Pharmaceuticals

Our current unhealthy lifestyle and the exponential surge in the population getting affected by a variety of diseases have made pharmaceuticals or drugs an imperative part of life, making the development of innovative strategies for drug discovery or the introduction of refined, cost-effective and modern technologies for the synthesis of clinically used drugs, a need of the hour. Ever since their discovery, free radicals and radical cations or anions as reactive intermediates have captivated the chemists, resulting in an exceptional utilization of these moieties throughout the field of chemical synthesis, owing to their unprecedented and widespread reactivity. Sticking with the idea of not judging the book by its cover, despite the conventional thought process of radicals being unstable and difficult to control entities, scientists and academicians around the globe have done an appreciable amount of work utilizing both persistent as well as transient radicals for a variety of organic transformations, exemplifying them with the synthesis of significant biologically active pharmaceutical ingredients. This review truly accounts for the organic radical transformations including radical addition, radical cascade cyclization, radical/radical cross-coupling, coupling with metal-complexes and radical cations coupling with nucleophiles, that offers fascinating and unconventional approaches towards the construction of intricate structural frameworks of marketed APIs with high atom- and step-economy; complementing the otherwise employed traditional methods. This tutorial review presents a comprehensive package of diverse methods utilized for radical generation, featuring their reactivity to form critical bonds in pharmaceutical total synthesis or in building key starting materials or intermediates of their synthetic journey, acknowledging their excellence, downsides and underlying mechanisms, which are otherwise poorly highlighted in the literature. Despite great achievements over the past few decades in this area, many challenges and obstacles are yet to be unraveled to shorten the distance between the academics and the industry, which are all discussed in summary and outlook.

Is Fibromyalgia a Fashionable Diagnosis or a Medical Mystery?

Despite its prevalence, there is no clear-cut diagnostic path or treatment paradigm for fibromyalgia; this can lead to a multiplicity of symptoms and comorbid conditions that complicate care. "Overlapping symptoms" describe conditions that can occur concomitantly with fibromyalgia and include migraine, irritable bowel syndrome, obesity, and pelvic pain syndromes. A variety of pharmacologic and nonpharmacologic treatments are available for fibromyalgia, but treatment is best personalized for an individual and recognizes potential comorbidities. Opioids are not the recommended front-line treatment, cannabinoids hold promise but with limitations and nonpharmacologic options, such as aerobic or resistance exercise and cognitive behavior therapy, can play a very important but often underestimated role. Amitriptyline appears to be safe and effective in treating six of the main fibromyalgia domains: pain, disturbed sleep, fatigue, affective symptoms, functional limitations, and impaired cognition ("fibro fog"). Very low-dose naltrexone (2.5-4.5 mg) may offer analgesic and anti-inflammatory benefits to fibromyalgia patients, but further studies are needed. Fibromyalgia can be a devastating and debilitating condition for patients, and clinicians are challenged with its diagnosis and treatment as well. Further research as well as compassionate approaches to offering personalized care to those with fibromyalgia are required.

Dopaminergic and norepinephrinergic modulation of endogenous event-related potentials: A systematic review and meta-analysis

Event-related potentials (ERPs) represent the cortical processing of sensory, motor or cognitive functions invoked by particular events or stimuli. A current theory posits that the catecholaminergic neurotransmitters dopamine (DA) and norepinephrine (NE) modulate a number of endogenous ERPs during various cognitive processes. This manuscript aims to evaluate a leading neurotransmitter hypothesis with a systematic overview and meta-analysis of pharmacologic DA and NE manipulation of specific ERPs in healthy subjects during executive function. Specifically, the frontally-distributed P3a, N2, and Ne/ERN (or error-related negativity) are supposedly modulated primarily by DA, whereas the parietally-distributed P3b is thought to be modulated by NE. Based on preceding research, we refer to this distinction between frontally-distributed DA-sensitive and parietally-distributed NE-sensitive ERP components as the Extended Neurobiological Polich (ENP) hypothesis. Our systematic review and meta-analysis indicate that this distinction is too simplistic and many factors interact with DA and NE to influence these specific ERPs. These may include genetic factors, the specific cognitive processes engaged, or elements of study design, i.e. session or sequence effects or data-analysis strategies.

Global Research Trends and Hotspots Analysis of the Scientific Production of Amitriptyline: A Bibliometric Approach

Amitriptyline was first introduced as a medication to treat depression. Over time, this substance has been used to treat other conditions, such as gastrointestinal disorders, fibromyalgia, neuropathic pain, and analgesia, among others. However, there are no published studies that provide a broad view of the possible motivations that have led to changes in the use of amitriptyline. In this study, we have identified the landscape of use for amitriptyline based on knowledge mapping of the 100 most-cited articles about this drug. We searched Web of Science Core Collection without time and language restrictions. We obtained 14,446 results, but we only used the 100 most-cited articles that had amitriptyline as the object of study. We collected the following information from each article: authors, country of the corresponding authors, year of publication, citation count, citation density (number of citations per year), and keywords. In addition, we seek to map in the chosen articles study design and research findings. We found that since 1980, the use of amitriptyline has expanded beyond depression, moving to off-label use to treat a variety of diseases and conditions, including post-herpetic neuralgia, neuropathic pain, primary fibrosis, fibromyalgia, and migraine, can be considered a drug with more clinical applicability than its original clinical indication.

Electrochemical Chemically Based Sensors and Emerging Enzymatic Biosensors for Antidepressant Drug Detection: A Review

Major depressive disorder is a widespread condition with antidepressants as the main pharmacological treatment. However, some patients experience concerning adverse reactions or have an inadequate response to treatment. Analytical chromatographic techniques, among other techniques, are valuable tools for investigating medication complications, including those associated with antidepressants. Nevertheless, there is a growing need to address the limitations associated with these techniques. In recent years, electrochemical (bio)sensors have garnered significant attention due to their lower cost, portability, and precision. Electrochemical (bio)sensors can be used for various applications related to depression, such as monitoring the levels of antidepressants in biological and in environmental samples. They can provide accurate and rapid results, which could facilitate personalized treatment and improve patient outcomes. This state-of-the-art literature review aims to explore the latest advancements in the electrochemical detection of antidepressants. The review focuses on two types of electrochemical sensors: Chemically modified sensors and enzyme-based biosensors. The referred papers are carefully categorized according to their respective sensor type. The review examines the differences between the two sensing methods, highlights their unique features and limitations, and provides an in-depth analysis of each sensor.

Inhibition of Microglial Activation by Amitriptyline and Doxepin in Interferon-β Pre-Treated Astrocyte–Microglia Co-Culture Model of Inflammation

Depression may occur in patients with multiple sclerosis, especially during interferon-β (IFN-β) treatment, and therapy with antidepressants may be necessary. Interactions of IFN-β with antidepressants concerning glia-mediated inflammation have not yet been studied. Primary rat co-cultures of astrocytes containing 5% (M5, consistent with “physiological” conditions) or 30% (M30, consistent with “pathological, inflammatory” conditions) of microglia were incubated with 10 ng/mL amitriptyline or doxepin for 2 h, or with 2000 U/mL IFN-β for 22 h. To investigate the effects of antidepressants on IFN-β treatment, amitriptyline or doxepin was added to IFN-β pre-treated co-cultures. An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was performed to measure the glial cell viability, immunocytochemistry was performed to evaluate the microglial activation state, and ELISA was performed to measure pro-inflammatory TNF-α and IL-6 cytokine concentrations. Incubation of inflammatory astrocyte–microglia co-cultures with amitriptyline, doxepin or IFN-β alone, or co-incubation of IFN-β pre-treated co-cultures with both antidepressants, significantly reduced the extent of inflammation, with the inhibition of microglial activation. TNF-α and IL-6 levels were not affected. Accordingly, the two antidepressants did not interfere with the anti-inflammatory effect of IFN-β on astrocytes and microglia. Furthermore, no cytotoxic effects on glial cells were observed. This is the first in vitro study offering novel perspectives in IFN-β treatment and accompanying depression regarding glia.

TCA and SSRI Antidepressants Exert Selection Pressure for Efflux-Dependent Antibiotic Resistance Mechanisms in Escherichia coli

Microbial diversity is reduced in the gut microbiota of animals and humans treated with selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs). The mechanisms driving the changes in microbial composition, while largely unknown, is critical to understand considering that the gut microbiota plays important roles in drug metabolism and brain function. Using Escherichia coli, we show that the SSRI fluoxetine and the TCA amitriptyline exert strong selection pressure for enhanced efflux activity of the AcrAB-TolC pump, a member of the resistance-nodulation-cell division (RND) superfamily of transporters. Sequencing spontaneous fluoxetine- and amitriptyline-resistant mutants revealed mutations in marR and lon, negative regulators of AcrAB-TolC expression. In line with the broad specificity of AcrAB-TolC pumps these mutants conferred resistance to several classes of antibiotics. We show that the converse also occurs, as spontaneous chloramphenicol-resistant mutants displayed cross-resistance to SSRIs and TCAs. Chemical-genomic screens identified deletions in marR and lon, confirming the results observed for the spontaneous resistant mutants. In addition, deletions in 35 genes with no known role in drug resistance were identified that conferred cross-resistance to antibiotics and several displayed enhanced efflux activities. These results indicate that combinations of specific antidepressants and antibiotics may have important effects when both are used simultaneously or successively as they can impose selection for common mechanisms of resistance. Our work suggests that selection for enhanced efflux activities is an important factor to consider in understanding the microbial diversity changes associated with antidepressant treatments. IMPORTANCE Antidepressants are prescribed broadly for psychiatric conditions to alter neuronal levels of synaptic neurotransmitters such as serotonin and norepinephrine. Two categories of antidepressants are selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs); both are among the most prescribed drugs in the United States. While it is well-established that antidepressants inhibit reuptake of neurotransmitters there is evidence that they also impact microbial diversity in the gastrointestinal tract. However, the mechanisms and therefore biological and clinical effects remain obscure. We demonstrate antidepressants may influence microbial diversity through strong selection for mutant bacteria with increased AcrAB-TolC activity, an efflux pump that removes antibiotics from cells. Furthermore, we identify a new group of genes that contribute to cross-resistance between antidepressants and antibiotics, several act by regulating efflux activity, underscoring overlapping mechanisms. Overall, this work provides new insights into bacterial responses to antidepressants important for understanding antidepressant treatment effects.

Investigation of the performance of cross-linked poly(acrylic acid) and poly(methacrylic acid) as efficient adsorbents in SPE columns for simultaneous preconcentration of tricyclic antidepressants in water samples

A solid phase extraction-based (SPE) procedure for simultaneous preconcentration of five tricyclic antidepressants (TCAs), amitriptyline hydrochloride (AMT), nortriptyline hydrochloride (NOR), doxepin hydrochloride (DOX), imipramine hydrochloride (IMI), and clomipramine hydrochloride (CLO) from water samples with determination by HPLC-DAD is proposed. Polymers were characterized by FT-IR, SEM, and thermogravimetric analysis. SPE-based methods were carried out by the preconcentration of 320.0 mL of TCAs at pH 7.0 (buffered with 0.01 mol L^-1 phosphate buffer) through 70.0 mg of adsorbent packed into a SPE cartridge, followed by elution with 1.0 mL of ACN : MeOH : acetic acid solution (45 : 45 : 10% v/v). Higher preconcentration factors were obtained ranging from 117.9 to 372.2 and 207.1 to 396.1 by using poly(MAA-co-EGDMA) and poly(AA-co-EGDMA), respectively, yielding lower limits of detection (0.03 to 0.12 μg L^-1) and (0.03 to 0.15 μg L^-1). These outcomes show satisfactory detectability of SPE-based methods, with slightly better performance using poly(MAA-co-EGDMA). On the other hand, poly(AA-co-EGDMA) was able to preconcentrate TCAs in the presence of humic acid (7.0 mg L^-1) without interference. The precision of methods assessed as RSD (%) was very similar, ranging from 1.7% to 16.3% for poly(MAA-co-EGDMA) and 1.7% to 13.4% for poly(AA-co-EGDMA). SPE cartridges packed with the polymers showed high reusability (52 cycles of preconcentration and elution) without losing adsorption efficiency. The methods were applied to determine TCAs in tap, lake, and stream water samples and the accuracy was attested by addition and recovery tests (86.7-116.0%), with determined nortriptyline ranging from 0.48 to 0.52 μg L^-1 in lake water samples.