A hypothesis of monoamine (5-HT) – Glutamate/GABA long neural circuit: Aiming for fast-onset antidepressant discovery

Effect of pharmacogenomic testing on the clinical treatment of patients with depressive disorder: A randomized clinical trial

BACKGROUND

Pharmacotherapy is one of the primary treatment modalities for depression. However, there is considerable variability in the individual response to antidepressant medications. Personalized medicine guided by pharmacogenomic testing may hold promise in addressing this issue.

METHODS

In this study, 665 depressive patients were randomly enrolled into two groups: the pharmacogenomic testing group (n = 333) and the control group (n = 332). In the testing group, participants underwent pharmacogenomic testing, and clinicians customized the treatment plan with the result, while the control group relied solely on clinicians' experience. The primary outcomes were the proportion of remission and response, assessed with Hamilton Depression Rating Scale (HDRS). The secondary outcomes included changes in HDRS scores over time and frequency of adverse drug reactions by the participants.

RESULTS

At week 8, the pharmacogenomic testing group showed significantly higher remission rates (24.0 % v.s. 15.1 %; RR = 1.117; P = 0.007) and response rates (39.3 % v.s. 25.7 %; RR = 1.225; P < 0.001) compared to the control group. By week 12, the pharmacogenomic testing group continued to demonstrate significant advantages in remission (31.0 % v.s. 20.0 %; RR = 1.159; P = 0.003) and response (48.7 % v.s. 37.3 %; RR = 1.224; P = 0.006). Additionally, adverse drug reactions were less frequent in the pharmacogenomic testing group.

LIMITATIONS

This study is not blind to clinicians and it's a single-center study.

CONCLUSIONS

Pharmacogenomic testing-guided drug therapy can provide greater assistance in the treatment of depression.

Advances in biosensors for major depressive disorder diagnostic biomarkers

Depression is one of the most common mental disorders and is mainly characterized by low mood or lack of interest and pleasure. It can be accompanied by varying degrees of cognitive and behavioral changes and may lead to suicide risk in severe cases. Due to the subjectivity of diagnostic methods and the complexity of patients' conditions, the diagnosis of major depressive disorder (MDD) has always been a difficult problem in psychiatry. With the discovery of more diagnostic biomarkers associated with MDD in recent years, especially emerging non-coding RNAs (ncRNAs), it is possible to quantify the condition of patients with mental illness based on biomarker levels. Point-of-care biosensors have emerged due to their advantages of convenient sampling, rapid detection, miniaturization, and portability. After summarizing the pathogenesis of MDD, representative biomarkers, including proteins, hormones, and RNAs, are discussed. Furthermore, we analyzed recent advances in biosensors for detecting various types of biomarkers of MDD, highlighting representative electrochemical sensors. Future trends in terms of new biomarkers, new sample processing methods, and new detection modalities are expected to provide a complete reference for psychiatrists and biomedical engineers.

Astrocyte-specific inhibition of sigma-1 receptor leads to depressive-like behaviors in mice via activation of NF-κB-induced neuroinflammation

Major depressive disorder (MDD) is a global health burden characterized by persistent low mood, deprivation of pleasure, recurrent thoughts of death, and physical and cognitive deficits. The current understanding of the pathophysiology of MDD is lacking, resulting in few rapid and effective antidepressant therapies. Recent studies have pointed to the sigma-1 (σ-1) receptor as a potential rapid antidepressant target; σ-1 agonists have shown promise in a variety of preclinical depression models. Hypidone hydrochloride (YL-0919), an independently developed antidepressant by our institute with faster onset of action and low rate of side effects, has recently emerged as a highly selective σ-1 receptor agonist; however, its underlying astrocyte-specific mechanism is unknown. In this study, we investigated the effect of YL-0919 treatment on gene expression in the prefrontal cortex of depressive-like mice by single-cell RNA sequencing. Furthermore, we knocked down σ-1 receptors on astrocytes in the medial prefrontal cortex of mice to explore the effects of YL-0919 on depressive-like behavior and neuroinflammation in mice. Our results demonstrated that astrocyte-specific knockdown of σ-1 receptor resulted in depressive-like behavior in mice, which was reversed by YL-0919 administration. In addition, astrocytic σ-1 receptor deficiency led to activation of the NF-κB inflammatory pathway, and crosstalk between reactive astrocytes and activated microglia amplified neuroinflammation, exacerbating stress-induced neuronal apoptosis. Furthermore, the depressive-like behavior induced by astrocyte-specific knockdown of the σ-1 receptor was improved by a selective NF-κB inhibitor, JSH-23, in mice. Our study not only reaffirms the σ-1 receptor as a key target of the faster antidepressant effect of YL-0919, but also contributes to the development of astrocytic σ-1 receptor-based novel drugs.

Microdosing ketamine in Drosophila does not block serotonin reuptake, but causes complex behavioral changes mediated by glutamate and serotonin receptors

Microdosing ketamine is a novel antidepressant for treatment-resistant depression. Traditional antidepressants, like selective serotonin reuptake inhibitors (SSRIs), inhibit serotonin reuptake, but it is not clear if ketamine shows a similar mechanism. Here, we tested the effects of feeding ketamine and SSRIs to Drosophila melanogaster larvae, which has a similar serotonin system to mammals and is a good model to track depressive behaviors, such as locomotion and feeding. Fast-scan cyclic voltammetry (FSCV) was used to measure optogenetically stimulated serotonin changes, and locomotion tracking software and blue dye feeding to monitor behavior. We fed larvae various doses (1-100 mM) of antidepressants for 24 h and found that 1 mM ketamine did not affect serotonin, but increased locomotion and feeding. Low doses (≤10 mM) of escitalopram and fluoxetine inhibited dSERT and also increased feeding and locomotion behaviors. At 100 mM, ketamine inhibited dSERT and increased serotonin concentrations, but decreased locomotion and feeding because of its anesthetic properties. Since microdosing ketamine causes behavioral effects, we further investigated behavioral changes with a SERT16 mutant and low doses of other NMDA receptor antagonists and 5-HT1A and 2 agonists. Feeding and locomotion changes were similar to ketamine in the mutant, and we found NMDA receptor antagonism increased feeding, while serotonin receptor agonism increased locomotion, which could explain these effects with ketamine. Ultimately, this work shows that Drosophila is a good model to discern antidepressant mechanisms, and that ketamine does not work on dSERT like SSRIs, but effects behavior with other mechanisms that should be investigated further.

Psilocybin promotes neuroplasticity and induces rapid and sustained antidepressant-like effects in mice

BACKGROUND

Psilocybin offers new hope for treating mood disorders due to its rapid and sustained antidepressant effects, as standard medications require weeks or months to exert their effects. However, the mechanisms underlying this action of psilocybin have not been identified.

AIMS

To investigate whether psilocybin has rapid and sustained antidepressant-like effects in mice and investigate whether its potential mechanisms of action are related to promoted neuroplasticity.

METHODS

We first examined the antidepressant-like effects of psilocybin in normal mice by the forced swimming test and in chronic corticosterone (CORT)-exposed mice by the sucrose preference test and novelty-suppressed feeding test. Furthermore, to explore the role of neuroplasticity in mediating the antidepressant-like effects of psilocybin, we measured structural neuroplasticity and neuroplasticity-associated protein levels in the prefrontal cortex (PFC) and hippocampus.

RESULTS

We observed that a single dose of psilocybin had rapid and sustained antidepressant-like effects in both healthy mice and chronic CORT-exposed mice. Moreover, psilocybin ameliorated chronic CORT exposure-induced inhibition of neuroplasticity in the PFC and hippocampus, including by increasing neuroplasticity (total number of dendritic branches and dendritic spine density), synaptic protein (p-GluA1, PSD95 and synapsin-1) levels, BDNF-mTOR signalling pathway activation (BDNF, TrkB and mTOR levels), and promoting neurogenesis (number of DCX-positive cells).

CONCLUSIONS

Our results demonstrate that psilocybin elicits robust, rapid and sustained antidepressant-like effects which is accompanied by the promotion of neuroplasticity in the PFC and hippocampus.

Fasting mimicking diet extends lifespan and improves intestinal and cognitive health

Caloric restriction is an effective means of extending a healthy lifespan. Fasting mimicking diet (FMD) is a growing pattern of caloric restriction. We found that FMD significantly prolonged the lifespan of prematurely aging mice. In naturally aging mice, FMD improved cognitive and intestinal health. Through a series of behavioral experiments, we found that FMD relieved anxiety and enhanced cognition in aged mice. In the intestine, the FMD cycles enhanced the barrier function, reduced senescence markers, and maintained T cell naïve-memory balance in the lamina propria mucosa. To further explore the causes of immune alterations, we examined changes in the stool microbiota using 16S rRNA sequencing. We found that FMD remodeled gut bacterial composition and significantly expanded the abundance of Lactobacillus johnsonii. Our research revealed that FMD has in-depth investigative value as an anti-aging intervention for extending longevity and improving cognition, intestinal function, and gut microbiota composition.

Sigma-1 receptor activation mediates the sustained antidepressant effect of ketamine in mice via increasing BDNF levels

Sigma-1 receptor (S1R) is a unique multi-tasking chaperone protein in the endoplasmic reticulum. Since S1R agonists exhibit potent antidepressant-like activity, S1R has become a novel target for antidepression therapy. With a rapid and sustained antidepressant effect, ketamine may also interact with S1R. In this study, we investigated whether the antidepressant action of ketamine was related to S1R activation. Depression state was evaluated in the tail suspension test (TST) and a chronic corticosterone (CORT) procedure was used to induce despair-like behavior in mice. The neuronal activities and structural changes of pyramidal neurons in medial prefrontal cortex (mPFC) were assessed using fiber-optic recording and immunofluorescence staining, respectively. We showed that pharmacological manipulation of S1R modulated ketamine-induced behavioral effect. Furthermore, pretreatment with an S1R antagonist BD1047 (3 mg·kg-1·d-1, i.p., for 3 consecutive days) significantly weakened the structural and functional restoration of pyramidal neuron in mPFC caused by ketamine (10 mg·kg-1, i.p., once). Ketamine indirectly triggered the activation of S1R and subsequently increased the level of BDNF. Pretreatment with an S1R agonist SA4503 (1 mg·kg-1·d-1, i.p., for 3 consecutive days) enhanced the sustained antidepressant effect of ketamine, which was eliminated by knockdown of BDNF in mPFC. These results reveal a critical role of S1R in the sustained antidepressant effect of ketamine, and suggest that a combination of ketamine and S1R agonists may be more beneficial for depression patients.

Activation of σ-1 receptor mitigates estrogen withdrawal-induced anxiety/depressive-like behavior in mice via restoration of GABA/glutamate signaling and neuroplasticity in the hippocampus

Postpartum depression (PPD) is a significant contributor to maternal morbidity and mortality. The Sigma-1 (σ-1) receptor has received increasing attention in recent years because of its ability to link different signaling systems and exert its function in the brain through chaperone actions, especially in neuropsychiatric disorders. YL-0919, a novel σ-1 receptor agonist developed by our institute, has shown antidepressive and anxiolytic effects in a variety of animal models, but effects on PPD have not been revealed. In the present study, excitatory/inhibitory signaling in the hippocampus was reflected by GABA and glutamate and their associated excitatory-inhibitory receptor proteins, the HPA axis hormones in the hippocampus were assessed by ELISA. Finally, immunofluorescence for markers of newborn neuron were undertaken in the dentate gyri, along with dendritic spine staining and dendritic arborization tracing. YL-0919 rapidly improves anxiety and depressive-like behavior in PPD-like mice within one week, along with normalizing the excitation/inhibition signaling as well as the HPA axis activity. YL-0919 rescued the decrease in hippocampal dendritic complexity and spine density induced by estrogen withdrawal. The study results suggest that YL-0919 elicits a therapeutic effect on PPD-like mice; therefore, the σ-1 receptor may be a novel promising target for PPD treatment in the future.

Electrochemical and biosensor techniques to monitor neurotransmitter changes with depression

Depression is a common mental illness. However, its current treatments, like selective serotonin reuptake inhibitors (SSRIs) and micro-dosing ketamine, are extremely variable between patients and not well understood. Three neurotransmitters: serotonin, histamine, and glutamate, have been proposed to be key mediators of depression. This review focuses on analytical methods to quantify these neurotransmitters to better understand neurological mechanisms of depression and how they are altered during treatment. To quantitatively measure serotonin and histamine, electrochemical techniques such as chronoamperometry and fast-scan cyclic voltammetry (FSCV) have been improved to study how specific molecular targets, like transporters and receptors, change with antidepressants and inflammation. Specifically, these studies show that different SSRIs have unique effects on serotonin reuptake and release. Histamine is normally elevated during stress, and a new inflammation hypothesis of depression links histamine and cytokine release. Electrochemical measurements revealed that stress increases histamine, decreases serotonin, and leads to changes in cytokines, like interleukin-6. Biosensors can also measure non-electroactive neurotransmitters, including glutamate and cytokines. In particular, new genetic sensors have shown how glutamate changes with chronic stress, as well as with ketamine treatment. These techniques have been used to characterize how ketamine changes glutamate and serotonin, and to understand how it is different from SSRIs. This review briefly outlines how these electrochemical techniques work, but primarily highlights how they have been used to understand the mechanisms of depression. Future studies should explore multiplexing techniques and personalized medicine using biomarkers in order to investigate multi-analyte changes to antidepressants.

A rate-limiting step in antidepressants onset: Excitation of glutamatergic pyramidal neurons in medial prefrontal cortex of rodents

Although clinical antidepressants have varied mechanisms of action, it remains unclear whether they may have a common mechanism underlying their antidepressant effects. We investigated the behavioral effects of five different antidepressants (differing in target, chemical structure, and rate of onset) and their effects on the firing activities of glutamatergic pyramidal neurons in the medial prefrontal cortex (mPFC) using the forced swimming test (FST) and electrophysiological techniques (in vivo). We employed fiber photometry recordings to validate the effects of antidepressants on the firing activity of pyramidal neurons. Additionally, multichannel electrophysiological recordings were conducted in mice exhibiting depressive-like behaviors induced by chronic restraint stress (CRS) to investigate whether antidepressants exert similar effects on pyramidal neurons in depressed mice. Behavioral tests were utilized for evaluating the depression model. We found that fluoxetine, duloxetine, vilazodone, YL-0919, and ketamine all increase the firing activities of glutamatergic pyramidal neurons (at least 57%) while exerting their initial onset of antidepressant effects. Fiber photometry revealed an increase in the calcium activity of pyramidal neurons in the mPFC at the onset of antidepressant effects. Furthermore, a significant reduction was observed in the firing activity of pyramidal neurons in the mPFC of CRS-exposed mice, which was reversed by antidepressants. Taken together, our findings suggested that five pharmacologically distinct classes of antidepressants share the common ability to increase the firing activity of pyramidal neurons, just different time, which might be a rate-limiting step in antidepressants onset. The study contributes to the body of knowledge of the mechanisms underlying antidepressant effects and paves the way for developing rapid-acting antidepressants.

The therapeutic effects of saikosaponins on depression through the modulation of neuroplasticity: From molecular mechanisms to potential clinical applications

Depression is a major global health issue that urgently requires innovative and precise treatment options. In this context, saikosaponin has emerged as a promising candidate, offering a variety of therapeutic benefits that may be effective in combating depression. This review delves into the multifaceted potential of saikosaponins in alleviating depressive symptoms. We summarized the effects of saikosaponins on structural and functional neuroplasticity, elaborated the regulatory mechanism of saikosaponins in modulating key factors that affect neuroplasticity, such as inflammation, the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, and the brain-gut axis. Moreover, this paper highlights existing gaps in current researches and outlines directions for future studies. A detailed plan is provided for the future clinical application of saikosaponins, advocating for more targeted researches to speed up its transition from preclinical trials to clinical practice.

Transient Adenosine Modulates Serotonin Release Indirectly in the Dorsal Raphe Nuclei

Rapid adenosine transiently regulates dopamine and glutamate via A1 receptors, but other neurotransmitters, such as serotonin, have not been studied. In this study, we examined the rapid modulatory effect of adenosine on serotonin release in the dorsal raphe nuclei (DRN) of mouse brain slices by using fast-scan cyclic voltammetry. To mimic adenosine release during damage, a rapid microinjection of adenosine at 50 pmol was applied before electrical stimulation of serotonin release. Transient adenosine significantly reduced electrically evoked serotonin release in the first 20 s after application, but serotonin release recovered to baseline as adenosine was cleared from the slice. The continuous perfusion of adenosine did not change the evoked serotonin release. Surprisingly, the modulatory effects of adenosine were not regulated by A1 receptors as adenosine still inhibited serotonin release in A1KO mice and also after perfusion of an A1 antagonist (8-cyclopentyl-1,3-dipropyl xanthine). The inhibition was also not regulated by A3 receptors as perfusion of the A3 antagonist (MRS 1220) in A1KO brain slices did not eliminate the inhibitory effects of transient adenosine. In addition, adenosine also inhibited serotonin release in A2AKO mice, showing that A2A did not modulate serotonin. However, perfusion of a selective 5HT1A autoreceptor antagonist drug [(S)-WAY 100135 dihydrochloride] abolished the inhibitory effect of transient adenosine on serotonin release. Thus, the transient neuromodulatory effect of adenosine on DRN serotonin release is regulated by serotonin autoreceptors and not by adenosine receptors. Rapid, transient adenosine modulation of neurotransmitters such as serotonin may have important implications for diseases such as depression and brain injury.

Fluoxetine mitigates depressive-like behaviors in mice via anti-inflammation and enhancing neuroplasticity

Neuroplasticity and inflammation represent a common final pathway for effective antidepressant treatment. SSRIs are the most commonly prescribed medications for depression and have demonstrated efficacy in reducing depressive symptoms. However, the precise impact of SSRIs on neuroplasticity and inflammation remains unclear. In this study, we aimed to investigate the influence of long-term treatment with SSRIs on hippocampal neuron, inflammation, synaptic function and morphology. Our findings revealed that fluoxetine treatment significantly alleviated behavioral despair, anhedonia, and anxiety in reserpine-treated mice. Moreover, fluoxetine mitigated hippocampal neuron impairment, inhibited inflammatory release, and increased the expression of synaptic proteins markers (SYP and PSD95) in mice. Notably, fluoxetine also suppressed reserpine-induced synapse loss in the hippocampus. Based on these results, fluoxetine has been demonstrated effectively to ameliorate depressive mood and cognitive dysfunction, possibly through the enhancement of synaptic plasticity. Overall, our study contributes to a further understanding of the mechanisms underlying the therapeutic effects of fluoxetine and its potential role in improving depressive symptoms and cognitive impairments.

PI3K-AKT/mTOR Signaling in Psychiatric Disorders: A Valuable Target to Stimulate or Suppress?

Economic development and increased stress have considerably increased the prevalence of psychiatric disorders in recent years, which rank as some of the most prevalent diseases globally. Several factors, including chronic social stress, genetic inheritance, and autogenous diseases, lead to the development and progression of psychiatric disorders. Clinical treatments for psychiatric disorders include psychotherapy, chemotherapy, and electric shock therapy. Although various achievements have been made researching psychiatric disorders, the pathogenesis of these diseases has not been fully understood yet, and serious adverse effects and resistance to antipsychotics are major obstacles to treating patients with psychiatric disorders. Recent studies have shown that the mammalian target of rapamycin (mTOR) is a central signaling hub that functions in nerve growth, synapse formation, and plasticity. The PI3K-AKT/mTOR pathway is a critical target for mediating the rapid antidepressant effects of these pharmacological agents in clinical and preclinical research. Abnormal PI3K-AKT/mTOR signaling is closely associated with the pathogenesis of several neurodevelopmental disorders. In this review, we focused on the role of mTOR signaling and the related aberrant neurogenesis in psychiatric disorders. Elucidating the neurobiology of the PI3K-AKT/mTOR signaling pathway in psychiatric disorders and its actions in response to antidepressants will help us better understand brain development and quickly identify new therapeutic targets for the treatment of these mental illnesses.

Treatment of Depression with Acupuncture Based on Pathophysiological Mechanism

Depression is a prevalent mental disorder and has a profound impact on an individual's psychological and physical well-being. It is characterized by a persistently depressed mood, loss of interest, energy loss, and cognitive dysfunction. In recent years, more and more people have changed to mental diseases, such as depression, anxiety, mania and so on. In the incidence of depression, covering all ages, but still mainly young and middle-aged women. Traditional treatments for depression mainly rely on medication and psychotherapy, but these methods are not effective for all patients and are often accompanied by certain side effects. Therefore, finding safe and effective alternative or adjuvant treatments has become a priority. Here we highlight the research progress of acupuncture in the treatment of depression and to explore the mechanism of acupuncture in the treatment of depression. Acupuncture treatment of depression is an ancient and effective method, the mechanism involves multiple biological pathways, for example, by regulating neurotransmitter levels, regulating the neuroendocrine axis, improving neuroplasticity, anti-inflammatory and other effects, improving emotional state and play an antidepressant role. To provide evidence to support the widespread use of acupuncture in clinical practice. We hope to provide new treatment ideas and methods for patients with depression, and even reduce the incidence of depression.

The rapid antidepressant effect of acupuncture on two animal models of depression by inhibiting M1-Ach receptors regulates synaptic plasticity in the prefrontal cortex

BACKGROUND

It is unclear whether acupuncture has a rapid antidepressant effect and what is the main mechanism.

METHODS

In this study, forced swimming stress test (FST) in mice were divided into five groups: control group, acupuncture group, scopolamine group, arecoline group, and acupuncture + arecoline group. Chronic unpredictable mild stress (CUMS) model rats were divided into six groups: naïve (non-CUMS) group, CUMS group, acupuncture group, scopolamine group, arecoline group, and acupuncture + arecoline group. Twenty-four hours after the end of treatment, FST was conducted in mice and rats. The expression of M1-AchR, AMPA receptors (GluR1 and GluR2), BDNF, mTOR, p-mTOR, synapsin I, and PSD95 in the prefrontal cortex was determined by western blot. The spine density of neurons in the prefrontal cortex was detected by golgi staining.

RESULTS

The results showed that acupuncture reduced the immobility time of FST in two depression models. Acupuncture inhibited the expression of M1-AchR and promoted the expression of GluR1, GluR2, BDNF, p-mTOR, synapsin I, PSD95, and increased the density of neuron dendritic spine in the prefrontal cortex.

CONCLUSIONS

The rapid antidepressant effect of acupuncture may be activating the "glutamate tide" - AMPA receptor activation - BDNF release - mTORC1 pathway activation through inhibiting the expression of M1-AchR in the prefrontal cortex, thereby increasing the expression of synaptic proteins and regulating synaptic plasticity.

Interplay of G-proteins and Serotonin in the Neuroimmunoinflammatory Model of Chronic Stress and Depression: A Narrative Review

INTRODUCTION

This narrative review addresses the clinical challenges in stress-related disorders such as depression, focusing on the interplay between neuron-specific and pro-inflammatory mechanisms at the cellular, cerebral, and systemic levels.

OBJECTIVE

We aim to elucidate the molecular mechanisms linking chronic psychological stress with low-grade neuroinflammation in key brain regions, particularly focusing on the roles of G proteins and serotonin (5-HT) receptors.

METHODS

This comprehensive review of the literature employs systematic, narrative, and scoping review methodologies, combined with systemic approaches to general pathology. It synthesizes current research on shared signaling pathways involved in stress responses and neuroinflammation, including calcium-dependent mechanisms, mitogen-activated protein kinases, and key transcription factors like NF-κB and p53. The review also focuses on the role of G protein-coupled neurotransmitter receptors (GPCRs) in immune and pro-inflammatory responses, with a detailed analysis of how 13 of 14 types of human 5-HT receptors contribute to depression and neuroinflammation.

RESULTS

The review reveals a complex interaction between neurotransmitter signals and immunoinflammatory responses in stress-related pathologies. It highlights the role of GPCRs and canonical inflammatory mediators in influencing both pathological and physiological processes in nervous tissue.

CONCLUSION

The proposed Neuroimmunoinflammatory Stress Model (NIIS Model) suggests that proinflammatory signaling pathways, mediated by metabotropic and ionotropic neurotransmitter receptors, are crucial for maintaining neuronal homeostasis. Chronic mental stress can disrupt this balance, leading to increased pro-inflammatory states in the brain and contributing to neuropsychiatric and psychosomatic disorders, including depression. This model integrates traditional theories on depression pathogenesis, offering a comprehensive understanding of the multifaceted nature of the condition.

Preclinical evaluation of ZL006-05, a new antistroke drug with fast-onset antidepressant and anxiolytic effects

BACKGROUND

Poststroke depression and anxiety, independent predictor of poor functional outcomes, are common in the acute phase of stroke. Up to now, there is no fast-onset antidepressive and anxiolytic agents suitable for the management of acute stroke. ZL006-05, a dual-target analgesic we developed, dissociates nitric oxide synthase from postsynaptic density-95 while potentiates α2-containing γ-aminobutyric acid type A receptor. This study aims to determine whether ZL006-05 can be used as an antistroke agent with fast-onset antidepressant and anxiolytic effects.

METHODS

Photothrombotic stroke and transient middle cerebral artery occlusion were induced in rats and mice. Infarct size was measured by TTC(2,3,5-Triphenyltetrazolium chloride) staining or Nissl staining. Neurological defects were assessed by four-point scale neurological score or modified Neurological Severity Scores. Grid-walking, cylinder and modified adhesive removal tasks were conducted to assess sensorimotor functions. Spatial learning was assessed using Morris water maze task. Depression and anxiety were induced by unpredictable chronic mild stress. Depressive behaviours were assessed by tail suspension, forced swim and sucrose preference tests. Anxiety behaviours were assessed by novelty-suppressed feeding and elevated plus maze tests. Pharmacokinetics, toxicokinetics and long-term toxicity studies were performed in rats.

RESULTS

Administration of ZL006-05 in the acute phase of stroke attenuated transient and permanent ischaemic injury and ameliorated long-term functional impairments significantly, with a treatment window of 12 hours after ischemia, and reduced plasminogen activato-induced haemorrhagic transformation. ZL006-05 produced fast-onset antidepressant and anxiolytic effects with onset latency of 1 hour in the normal and CMS mice, had antidepressant and anxiolytic effects in stroke mice. ZL006-05 crossed the blood-brain barrier and distributed into the brain rapidly, and had a high safety profile in toxicokinetics and long-term toxicological studies.

CONCLUSION

ZL006-05 is a new neuroprotectant with fast-onset antidepressant and anxiolytic effects and has translational properties in terms of efficacy, safety and targeting of clinical issues.

Value of Chuanjin Qinggan decoction in improving the depressive state of patients with herpes zoster combined with depression

BACKGROUND

Western medicine is beneficial for the recovery of neurological function in patients with depression, but some patients experience side effects such as headaches, dizziness, nausea, gastrointestinal symptoms, insomnia, and cardiac dysfunction. In recent years, integrative medicine has achieved positive results in the treatment of various diseases.

AIM

To study Chuanjin Qinggan decoction combined with selective serotonin reuptake inhibitors (SSRIs) in patients with herpes zoster complicated by depression.

METHODS

Patients with herpes zoster complicated by depression who were treated at the Yantai Hospital of Traditional Chinese Medicine from January 2021 to December 2022 were retrospectively selected as research participants. Among them, 43 patients with herpes zoster complicated by depression who received SSRI treatment between January and December 2021 were assigned to the Western medicine group, while those who received combined treatment of traditional Chinese and Western medicine between January and December 2022 were assigned to the combined group. Both groups were treated for eight weeks. The degree of pain, effect of herpes zoster treatment, degree of improvement in depressive symptoms, serum neurotransmitter levels, sleep quality, and occurrence of adverse reactions were compared between the two groups.

RESULTS

We found that after eight weeks of drug treatment, the two treatment schemes achieved differing efficacy. In further comparison, we found that, compared with patients treated with SSRIs alone, patients treated with Chuanjin Qinggan decoction combined with SSRIs showed more significant improvement in depression and a greater increase in dopamine and 5-hydroxytryptamine levels after treatment (P < 0.05). Patients treated with Chuanjin Qinggan decoction combined with SSRIs also experienced lower pain, better treatment efficacy for herpes zoster, better sleep quality, and a lower incidence of adverse reactions compared to those treated with SSRIs alone (P < 0.05). All minor adverse reactions occurring during treatment were resolved after symptomatic treatment.

CONCLUSION

The treatment scheme of Chuanjin Qinggan decoction combined with SSRIs can improve the psychological state of patients with herpes zoster complicated by depression and alleviate adverse reactions.

Geraniol attenuates behavioral and neurochemical impairments by inhibitions of HPA-axis and oxido-inflammatory perturbations in mice exposed to post-traumatic stress disorder

Geraniol is an acyclic isoprenoid monoterpenoid analogue that has been shown to elicit neuroprotective functions, primarily through its ability to stimulate antioxidant and anti-inflammatory systems. An increase in inflammatory cytokines and oxidative stress exacerbate activation hypothalamic-pituitary-adrenal axis (HPA), leading to neurochemical dysfunction, which has important roles in the pathogenesis of post-traumatic disorder (PTSD), a mental health disorder characterized of post-trauma-induced intense fear. The aim of this study was to evaluate the anti-PTSD-like effects and underlying mechanisms of geraniol against single-prolonged-stress (SPS)-induced PTSD in mice. Following concomitant exposure to SPS (triple-paradigm traumatic events) and isolation for 7 days, mice (n = 9) were treated with geraniol (50 and 100 mg/kg, p.o.) or fluoxetine (10 mg/kg, p.o.) from days 8-21. Mice were assessed for behavioral changes. Neurochemical changes, inflammatory, oxido-nitrergic markers, adrenal weight, serum glucose and corticosterone concentrations were assayed. Geraniol inhibits SPS-induced anxiety- and depressive-like features as well as behavioral despair in the depression paradigms. SPS-induced locomotor and memory impairments were also abated by geraniol treatment similarly to fluoxetine. SPS-induced adrenal hypertrophy and increased blood glucose and corticosterone concentrations, were attenuated by the geraniol treatment. Elevated levels of TNF-α and IL-6, and malondialdehyde, nitrite, acetylcholinesterase enzyme were reduced by geraniol. Geraniol also increased glutathione, superoxide-dismutase, and catalase levels as well as dopamine, serotonin concentrations and GABAergic glutamic acid decarboxylase enzyme activity in the striatum, prefrontal cortex and hippocampus in the PTSD-mice relative to SPS control. In conclusion, geraniol attenuates behavioral impairments and neurochemical dysregulations by inhibitions of HPA-axis and oxido-inflammatory perturbations in mice exposed to PTSD.

Repeated reserpine treatment induces depressive-like behaviors accompanied with hippocampal impairment and synapse deficit in mice

Depression remains a significant public health concern, and current animal models of depression are limited in their ability to accurately mimic human depression. However, studying the new development of antidepressants requires the use of progressive animal models. In this study, the mice were exposed to a low dose of reserpine (0.5 mg/kg) once daily for 14 days, followed by a 14-day period to allow for the development of spontaneous depression. We have successfully established a repeated reserpine-induced depressive animal model, which was characterized by emotional symptoms (anhedonia), cognitive symptoms, and psychomotor agitation or retardation. Our study demonstrated that repeated treatment with low-dose reserpine increased immobility time in the TST and FST. It also decreased the sucrose consumption ratio and induced anxiety-like behaviors. These anxiety-like behaviors were evidenced by decreased time spent in the center zone, longer first latency to center zone, and fewer entries into the center zone in the open field test. These findings support the utility of the low-dose reserpine repeated injection animal model for studying the pathogenesis of depression and the development of novel antidepressant treatments. Additionally, this study provides valuable insights into the potential of low-dose reserpine as a tool for modeling chronic depression in animals. Furthermore, our findings suggest that prolonged low-dose reserpine treatment could result in chronic depression. These findings have significant implications for the use of reserpine as a therapeutic agent for various conditions and emphasize the importance of closely monitoring patients' mental health.

Microdosing ketamine in Drosophila does not inhibit SERT like SSRIs, but causes behavioral changes mediated by glutamate and serotonin receptors

Recently, the FDA approved microdosing ketamine for treatment resistant depression. Traditional antidepressants, like serotonin selective reuptake inhibitors (SSRIs), block serotonin reuptake, but it is not clear if ketamine blocks serotonin reuptake. Here, we tested the effects of feeding ketamine and SSRIs to Drosophila melanogaster larvae, which has a similar serotonin system to mammals, and is a good model to track depression behaviors, such as locomotion and feeding. Fast-scan cyclic voltammetry (FSCV) was used to measure optogenetically-stimulated serotonin changes, and locomotion tracking software and blue dye feeding to monitor behavior. We fed larvae various doses (1-100 mM) of antidepressants for 24 hours and found that 1 mM ketamine did not affect serotonin, but increased locomotion and feeding. Low doses (≤ 10 mM) of escitalopram and fluoxetine inhibited dSERT and also increased feeding and locomotion behaviors. At 100 mM, ketamine inhibited dSERT and increased serotonin concentrations, but decreased locomotion and feeding due to its anesthetic properties. Since microdosing ketamine causes behavioral effects, we also investigated behavior changes with low doses of other NMDA receptor antagonists and 5-HT1A and 2 agonists, which are other possible sites for ketamine action. NMDA receptor antagonism increased feeding, while serotonin receptor agonism increased locomotion, which could explain these effects with ketamine. Ultimately, this work shows that Drosophila is a good model to discern antidepressant mechanisms, and that ketamine does not work on dSERT like SSRIs at microdoses, but affects behavior with other mechanisms.

Recent Progress in Mass Spectrometry-Based Metabolomics in Major Depressive Disorder Research

Major depressive disorder (MDD) is a serious mental illness with a heavy social burden, but its underlying molecular mechanisms remain unclear. Mass spectrometry (MS)-based metabolomics is providing new insights into the heterogeneous pathophysiology, diagnosis, treatment, and prognosis of MDD by revealing multi-parametric biomarker signatures at the metabolite level. In this comprehensive review, recent developments of MS-based metabolomics in MDD research are summarized from the perspective of analytical platforms (liquid chromatography-MS, gas chromatography-MS, supercritical fluid chromatography-MS, etc.), strategies (untargeted, targeted, and pseudotargeted metabolomics), key metabolite changes (monoamine neurotransmitters, amino acids, lipids, etc.), and antidepressant treatments (both western and traditional Chinese medicines). Depression sub-phenotypes, comorbid depression, and multi-omics approaches are also highlighted to stimulate further advances in MS-based metabolomics in the field of MDD research.

Pathogenesis and treatment of depression: Role of diet in prevention and therapy

In recent years, there has been a significant increase in depression, which is related to, among other things, the COVID-19 pandemic. Depression can be fatal if not treated or if treated inappropriately. Depression is the leading cause of suicide attempts. The disease is multifactorial, and pharmacotherapy often fails to bring satisfactory results. Therefore, increasingly more importance is attached to the natural healing substances and nutrients in food, which can significantly affect the therapy process and prevention of depressive disorders. A proper diet is vital to preventing depression and can be a valuable addition to psychological and pharmacologic treatment. An inadequate diet may reduce the effectiveness of antidepressants or increase their side effects, leading to life-threatening symptoms. This study aimed to review the literature on the pathogenesis of the development and treatment of depression, with particular emphasis on dietary supplements and the role of nutrition in the prevention and treatment of depressive disorders.

Pharmacological evidence for glutamatergic pathway involvement in the antidepressant-like effects of 2-phenyl-3-(phenylselanyl)benzofuran in male Swiss mice

Depression is a multifactorial and heterogeneous disease with several neurobiological mechanisms underlying its pathophysiology, including dysfunctional glutamatergic neurotransmission, which makes the exploration of the glutamate pathway an interesting strategy for developing novel rapid-acting antidepressant treatments. In the present study, we aimed to evaluate the possible glutamatergic pathway relation in the antidepressant-like action of 2-phenyl-3-(phenylselanyl)benzofuran (SeBZF1) in Swiss mice employing the tail suspension test (TST). Male Swiss mice received drugs targeting glutamate receptors before acute SeBZF1 administration at effective (50 mg/kg) or subeffective (1 mg/kg) doses by intragastric route (ig). TST and the open-field test (OFT) were employed in all behavioral experiments. The pretreatment of mice with N-methyl-D-aspartate (NMDA) (0.1 pmol/site, intracerebroventricular, icv, a selective agonist of the NMDA receptors), D-serine (30 µg/site, icv, a co-agonist at the NMDA receptor), arcaine (1 mg/kg, intraperitoneal, ip, an antagonist of the polyamine-binding site at the NMDA receptor), and 6,7-dinitroquinoxaline-2,3-dione (DNQX) (2,5 µg/site, icv, an antagonist of the AMPA/kainate type of glutamate receptors) inhibited the antidepressant-like effects of SeBZF1 (50 mg/kg, ig) in the TST. Coadministration of a subeffective dose of SeBZF1 with low doses of MK-801 (0.001 mg/kg, ip, a non-competitive NMDA receptor antagonist) or ketamine (0.1 mg/kg, ip, a non-selective antagonist of the NMDA receptors) produced significant antidepressant-like effects (synergistic action). These findings suggest the involvement of the glutamatergic system, probably through modulation of ionotropic glutamate receptors, in the antidepressant-like action of SeBZF1 in mice and contribute to a better understanding of the mechanisms underlying its pharmacological effects.

The Role of the Adrenal-Gut-Brain Axis on Comorbid Depressive Disorder Development in Diabetes

Diabetic patients are more affected by depression than non-diabetics, and this is related to greater treatment resistance and associated with poorer outcomes. This increase in the prevalence of depression in diabetics is also related to hyperglycemia and hypercortisolism. In diabetics, the hyperactivity of the HPA axis occurs in parallel to gut dysbiosis, weakness of the intestinal permeability barrier, and high bacterial-product translocation into the bloodstream. Diabetes also induces an increase in the permeability of the blood-brain barrier (BBB) and Toll-like receptor 4 (TLR4) expression in the hippocampus. Furthermore, lipopolysaccharide (LPS)-induced depression behaviors and neuroinflammation are exacerbated in diabetic mice. In this context, we propose here that hypercortisolism, in association with gut dysbiosis, leads to an exacerbation of hippocampal neuroinflammation, glutamatergic transmission, and neuronal apoptosis, leading to the development and aggravation of depression and to resistance to treatment of this mood disorder in diabetic patients.

Integrated pathway and network analyses of metabolomic alterations in peripheral blood of patients with depression

Depression is a serious mental illness, but the molecular mechanisms of depression remain unclear. Previous research has reported metabolomic changes in the blood of patients with depression, while integrated analysis based on these altered metabolites was still lacking. The objective of this study was to integrate metabolomic changes to reveal the underlying molecular alternations of depression. We retrieved altered metabolites in the blood of patients with depression from the MENDA database. Pathway analysis was conducted to explore enriched pathways based on candidate metabolites. Pathway crosstalk analysis was performed to explore potential correlations of these enriched pathways, based on their shared candidate metabolites. Moreover, potential interactions of candidate metabolites with other biomolecules such as proteins were assessed by network analysis. A total of 854 differential metabolite entries were retrieved in peripheral blood of patients with depression, including 555 unique candidate metabolites. Pathway analysis identified 215 significantly enriched pathways, then pathway crosstalk analysis revealed that these pathways were clustered into four modules, including amino acid metabolism, nucleotide metabolism, energy metabolism and others. Additionally, eight molecular networks were identified in the molecular network analysis. The main functions of these networks involved amino acid metabolism, molecular transport, inflammatory responses and others. Based on integrated analysis, our study revealed pathway-based modules and molecular networks associated with depression. These results will contribute to the underlying knowledge of the molecular mechanisms in depression.

Under the umbrella of depression and Alzheimer's disease physiopathology: Can cannabinoids be a dual-pleiotropic therapy?

Depression and Alzheimer´s disease (AD) are two disorders highly prevalent worldwide. Depression affects more than 300 million people worldwide while AD affects 60-80% of the 55 million cases of dementia. Both diseases are affected by aging with high prevalence in elderly and share not only the main brain affected areas but also several physiopathological mechanisms. Depression disease is already ascribed as a risk factor to the development of AD. Despite the wide diversity of pharmacological treatments currently available in clinical practice for depression management, they remain associated to a slow recovery process and to treatment-resistant depression. On the other hand, AD treatment is essentially based in symptomatology relieve. Thus, the need for new multi-target treatments arises. Herein, we discuss the current state-of-art regarding the contribution of the endocannabinoid system (ECS) in synaptic transmission processes, synapses plasticity and neurogenesis and consequently the use of exogenous cannabinoids in the treatment of depression and on delaying the progression of AD. Besides the well-known imbalance of neurotransmitter levels, including serotonin, noradrenaline, dopamine and glutamate, recent scientific evidence highlights aberrant spine density, neuroinflammation, dysregulation of neurotrophic factor levels and formation of amyloid beta (Aβ) peptides, as the main physiopathological mechanisms compromised in depression and AD. The contribution of the ECS in these mechanisms is herein specified as well as the pleiotropic effects of phytocannabinoids. At the end, it became evident that Cannabinol, Cannabidiol, Cannabigerol, Cannabidivarin and Cannabichromene may act in novel therapeutic targets, presenting high potential in the pharmacotherapy of both diseases.

Research on Xiaoyao Powder in the treatment of depression based on epigenetics and quality markers

Depression has become one of the most common public health issues around the world, and the incidence has been increasing in recent years. A large amount of clinical investigations have proven that the treatment of depression is difficult. The prognosis is poor, and the fatality rate is high. At present, western medicine is the preferred treatment for depression, but it often causes adverse clinical reactions such as dry mouth, blurred vision, and memory loss, etc. The herbal compound Xiaoyao Powder is a traditional medicine for soothing the liver and relieving depression, strengthening the spleen, and nourishing the blood. It can reduce adverse reactions. It is effective in treating depression. In this study, we elucidate the function of Xiaoyao Powder in anti-depression from the perspective of clinical application and pharmacological mechanisms such as regulating epigenetic and chemical quality markers to provide empirical and experimental theoretical results that contribute to developing future depression therapy with Xiaoyao Powder.

Targeting Mitochondrial Homeostasis: The Role of Acupuncture in Depression Treatment

Background

Depression is a common mental health disorder characterized by persistent feelings of sadness, loss of interest or pleasure, and a range of physical and cognitive symptoms. It affects people of all ages and can significantly impact their daily functioning and quality of life. Mitochondrial homeostasis plays an important role in the pathogenesis of depression. Mitochondrial homeostasis includes mitophagy, mitochondrial oxidative stress, mitoptosis, mitochondrial biogenesis, and mitochondrial dynamics. The regulation of mitochondrial homeostasis is the key link in the prevention and treatment of depression.

Methods

In this article, we focus on the core link of depression-mitochondrial homeostasis and summarize the research progress of acupuncture targeting mitochondrial homeostasis in the treatment of depression in recent years, so as to provide ideas and experimental basis for the research and formulation of more appropriate depression treatment strategies.

Results

Acupuncture has been found to regulate mitochondrial homeostasis (by modulating mitochondrial autophagy, reducing mitochondrial oxidative stress, inhibiting mitochondrial fission, inducing mitochondrial biogenesis, and maintaining mitochondrial dynamics), alleviate depression-like behavior, and regulate signal pathways and key proteins.

Conclusion

Here, we highlight the role of acupuncture in the treatment of depression. A comprehensive exploration of the impact of acupuncture on mitochondrial homeostasis could potentially present a novel mechanism for treating depression and offer fresh perspectives for the treatment of patients with clinical depression.

Essential role of microglia in the fast antidepressant action of ketamine and hypidone hydrochloride (YL-0919)

Introduction: Intracerebral microglia play a vital role in mediating central immune response, neuronal repair and synaptic pruning, but its precise role and mechanism in fast action of antidepressants have remained unknown. In this study, we identified that the microglia contributed to the rapid action of antidepressants ketamine and YL-0919. Methods: The depletion of microglia was achieved with the diet containing the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 in mice. The tail suspension test (TST), forced swimming test (FST) and novelty suppressed feeding test (NSFT) were employed to evaluate the rapid acting antidepressant behavior of ketamine and YL-0919 in the microglia depletion model. The number of microglia in the prefrontal cortex (PFC) was assayed by the immunofluorescence staining. The expressions of synaptic proteins (synapsin-1, PSD-95, GluA1) and brain-derived neurotrophic factor (BDNF) in the PFC were tested by Western blot. Results: The immobility duration in FST and the latency to feed in NSFT were shortened 24 h after an intraperitoneal (i.p.) injection of ketamine (10 mg/kg). The microglial depletion of PLX3397 blocked the rapid antidepressant-like effect of ketamine in mice. In addition, the immobility time in TST and FST as well as latency to feed in NSFT were reduced 24 h after the intragastric (i.g.) administration of YL-0919 (2.5 mg/kg), and the rapid antidepressant effect of YL-0919 was also blocked by the microglial depletion using PLX5622. About 92% of microglia in the prefrontal cortex was depleted in PLX5622 diet-fed mice, while both ketamine and YL-0919 promoted proliferation on the remaining microglia. YL-0919 significantly increased the protein expressions of synapsin-1, PSD-95, GluA1 and BDNF in the PFC, all of which could be blocked by PLX5622. Conclusion: These results suggested the microglia underlying the rapid antidepressant-like effect of ketamine and YL-0919, and microglia would likely constitute in the rapid enhancing impact of synaptic plasticity in the prefrontal cortex by YL-0919.

Loganin improves chronic unpredictable mild stress-induced depressive-like behaviors and neurochemical dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE

Cornus officinalis Sieb. et Zucc., is a valuable herb commonly used in Chinese medicine clinics. Loganin is a major iridoid glycoside obtained from the traditional Chinese herb Corni Fructus. Loganin, which has been shown to improve depression-like behavior in mice exposed to acute stress, is probably a potential antidepressant candidate.

AIM OF THE STUDY

Loganin was evaluated for its effect on chronic unpredictable mild stress (CUMS) induced depressive-like mice, and its action mechanisms were explored.

MATERIALS AND METHODS

ICR mice were subjected to the CUMS stimulation method to induce depression. The therapeutic effect of loganin on depressive-like behavior was evaluated by a series of behavioral tests such as sucrose preference test (SPT), forced swim test (FST), tail suspension test (TST) and open-field test (OFT). In addition, the serum levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) were measured using ELISA. The levels of monoamine neurotransmitters were detected by high performance liquid chromatography-electrochemical detection (HPLC-ECD). The levels of brain-derived neurotrophic factor (BDNF) in the hippocampus were measured using western blot analysis.

RESULTS

The results showed that CUMS induced depressive-like behaviors in mice, as indicated by behavioral tests. Administration of loganin increased the sucrose preference in SPT, as well as decreased the immobility time in FST and TST. Loganin could also improve food intake, and increased crossing times in the OFT. In mechanism, loganin restored the secretion of monoamine neurotransmitters, ACTH and CORT to normal levels. In addition, loganin elevated the expression of BDNF in the hippocampus. In conclusion, loganin exerts antidepressant-like effects in CUMS model mice through modulating monoamine neurotransmitters, ACTH, CORT and BDNF.

CONCLUSION

Loganin effectively ameliorated depressive-like symptoms in CUMS-exposed mice by increasing 5-hydroxytryptamine (5-HT) and dopamine (DA) levels, alleviating hypothalamic-pituitary-adrenal (HPA) axis dysfunction, and increasing BDNF expression. In conclusion, the findings of the current study extensive evidence for the application of loganin in stress-associated disorders, specifically targeting depression.

Ferulic acid as a therapeutic agent in depression: Evidence from preclinical studies

Depression is a common but severe mood disorder with a very high prevalence across the general population. Depression is of global concern and poses a threat to human physical and mental health. Ferulic acid (FA) is a natural active ingredient that has antioxidative, anti-inflammatory, and free radical scavenging properties. Furthermore, studies have shown that FA can exert antidepressant effects through a variety of mechanisms. The aim of the review was to comprehensively elucidate the mechanisms in FA that alleviate depression using animal models. The in vivo (animal) studies on the mechanism of FA treatment of depression were searched in PubMed, Chinese National Knowledge Infrastructure, Baidu academic, and Wan fang databases. Thereafter, the literature conclusions were summarized accordingly. Ferulic acid was found to significantly improve the depressive-like behaviors of animal models, suggesting that FA is a potential natural product in the treatment of depression. The mechanisms are achieved by enhancing monoamine oxidase A (MOA) activity, inhibiting microglia activation and inflammatory factor release, anti-oxidative stress, promoting hippocampal nerve regeneration, increasing brain-derived neurotrophic factor secretion, regulating gut microbiome, and activating protein kinase B/collapsin response mediator protein 2 (AKT/CRMP2) signaling pathway. Ferulic acid produces significant antidepressant effects in animal depression models through various mechanisms, suggesting its potential value as a treatment of depression. However, clinical research trials involving FA are required further to provide a solid foundation for its clinical application.

Flavonols in Action: Targeting Oxidative Stress and Neuroinflammation in Major Depressive Disorder

Major depressive disorder is one of the most common mental illnesses that highly impairs quality of life. Pharmacological interventions are mainly focused on altered monoamine neurotransmission, which is considered the primary event underlying the disease's etiology. However, many other neuropathological mechanisms that contribute to the disease's progression and clinical symptoms have been identified. These include oxidative stress, neuroinflammation, hippocampal atrophy, reduced synaptic plasticity and neurogenesis, the depletion of neurotrophic factors, and the dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis. Current therapeutic options are often unsatisfactory and associated with adverse effects. This review highlights the most relevant findings concerning the role of flavonols, a ubiquitous class of flavonoids in the human diet, as potential antidepressant agents. In general, flavonols are considered to be both an effective and safe therapeutic option in the management of depression, which is largely based on their prominent antioxidative and anti-inflammatory effects. Moreover, preclinical studies have provided evidence that they are capable of restoring the neuroendocrine control of the HPA axis, promoting neurogenesis, and alleviating depressive-like behavior. Although these findings are promising, they are still far from being implemented in clinical practice. Hence, further studies are needed to more comprehensively evaluate the potential of flavonols with respect to the improvement of clinical signs of depression.

Astrocytes underlie a faster-onset antidepressant effect of hypidone hydrochloride (YL-0919)

Introduction: Major depression disorder (MDD) is a common and potentially life-threatening mental illness; however, data on its pathogenesis and effective therapeutic measures are lacking. Pathological changes in astrocytes play a pivotal role in MDD. While hypidone hydrochloride (YL-0919), an independently developed antidepressant, has shown rapid action with low side effects, its underlying astrocyte-specific mechanisms remain unclear.

Methods: In our study, mice were exposed to chronic restraint stress (CRS) for 14 days or concomitantly administered YL-0919/fluoxetine. Behavioral tests were applied to evaluate the depression model; immunofluorescence and immunohistochemistry staining were used to explore morphological changes in astrocytes; astrocyte-specific RNA sequencing (RNA-Seq) analysis was performed to capture transcriptome wide alterations; and ATP and oxygen consumption rate (OCR) levels of primary astrocytes were measured, followed by YL-0919 incubation to appraise the alteration of energy metabolism and mitochondrial oxidative phosphorylation (OXPHOS).

Results: YL-0919 alleviated CRS-induced depressive-like behaviors faster than fluoxetine and attenuated the number and morphologic deficits in the astrocytes of depressed mice. The changes of gene expression profile in astrocytes after CRS were partially reversed by YL-0919. Moreover, YL-0919 improved astrocyte energy metabolism and mitochondrial OXPHOS in astrocytes.

Conclusion: Our results provide evidence that YL-0919 exerted a faster-onset antidepressant effect on CRS-mice possibly via astrocyte structural remodeling and mitochondria functional restoration.

Prophylactic effect of Tongxieyaofang polysaccharide on depressive behavior in adolescent male mice with chronic unpredictable stress through the microbiome-gut-brain axis

Major depression disorder is more common among adolescents and is a primary reason for suicide in adolescents. Some antidepressants are ineffective and may possess side effects. Therefore, developing an adolescent antidepressant is the need of the hour. We designed the stress model of adolescent male mice induced by chronic unpredictable stress (CUS). The mice were treated using Tongxieyaofang neutral polysaccharide (TXYF-NP), Tongxieyaofang acidic polysaccharide (TXYF-AP), TXYF-AP + TXYF-NP and fructooligosaccharide + galactooligosaccharides to determine their body weight, behavior, and serum hormone levels. RT-qPCR was used to detect the gene expression of Crhr1, Nr3c1, and Nr3c2 in the hypothalamus and hippocampus and the gene expression of glutamic acid and γ-aminobutyric acid-related receptors in the hippocampus. RT-qPCR, Western blot, and ELISA detected tryptophan metabolism in the colon, serum, and hippocampus. 16s rDNA helped sequence colon microflora, and non-targeted metabolomics enabled the collection of metabolic profiles of colon microflora. In adolescent male mice, CUS induced depression-like behavior, hypothalamic-pituitary-adrenal axis hyperactivity, hippocampal tissue damage, abnormal expression of its related receptors, and dysregulation of tryptophan metabolism. The 16s rDNA and non-targeted metabolomics revealed that CUS led to colon microflora disorder and bile acid metabolism abnormality. Tongxieyaofang polysaccharide could improve the bacterial community and bile acid metabolism disorder by upregulating the relative abundance of Lactobacillus gasseri, Lachnospiraceae bacterium 28-4, Bacteroides and Ruminococcaceae UCG-014 while preventing CUS-induced changes. TXYF-P can inhibit depression-like behavior due to CUS by regulating colonic microflora and restoring bile acid metabolism disorder. Thus, based on the different comparisons, TXYF-NP possessed the best effect.

Sigma-1 receptor agonist properties that mediate the fast-onset antidepressant effect of hypidone hydrochloride (YL-0919)

The most intriguing characteristic of the sigma-1 receptor is its ability to regulate multiple functional proteins directly via protein-protein interactions, giving the sigma-1 receptor the powerful ability to regulate several survival and metabolic functions in cells, fine tune neuronal excitability, and regulate the transmission of information within brain circuits. This characteristic makes sigma-1 receptors attractive candidates for the development of new drugs. Hypidone hydrochloride (YL-0919), a novel structured antidepressant candidate developed in our laboratory, possess a selective sigma-1 receptor agonist profile, as evidenced by molecular docking, radioligand receptor binding assays, and receptor functional experiments. In vivo studies have revealed that YL-0919 elicits a fast-onset antidepressant activity (within one week) that can be attenuated with pretreatment of the selective sigma-1 receptor antagonist, BD-1047. Taken together, the findings of the current study suggest that YL-0919 activates the sigma-1 receptor to partially mediate the rapid onset antidepressant effects of YL-0919. Thus, YL-0919 is a promising candidate as a fast-onset antidepressant that targets the sigma-1 receptor.

Nomogram including indirect bilirubin for the prediction of post-stroke depression at 3 months after mild acute ischemic stroke onset

Background

Post-stroke depression (PSD) has been proven to be associated with stroke severity. Thus, we hypothesized that the prevalence of PSD would be lower in patients with mild stroke. We aim to explore predictors of depression at 3 months after mild acute ischemic stroke (MAIS) onset and to develop a practical and convenient prediction model for the early identification of patients at high risk.

Methods

A total of 519 patients with MAIS were consecutively recruited from three hospitals in Wuhan city, Hubei province. MAIS was defined as a National Institute of Health Stroke Scale (NIHSS) score of ≤5 at admission. Meeting the DSM-V diagnostic criteria and a 17-item Hamilton Rating Scale for Depression (HAMD-17) score of >7 at their 3-month follow-up were considered the primary outcomes. A multivariable logistic regression model was used to determine the factors adjusted for potential confounders, and all independent predictors were brought into the construction of a nomogram to predict PSD.

Results

The prevalence of PSD is up to 32% at 3 months after MAIS onset. After adjusting for potential confounders, indirect bilirubin (p = 0.029), physical activity (p = 0.001), smoking (p = 0.025), hospitalization days (p = 0.014), neuroticism (p < 0.001), and MMSE (p < 0.001) remained independently and significantly related with PSD. The concordance index (C-index) of the nomogram jointly constructed by the aforementioned six factors was 0.723 (95% CI: 0.678-0.768).

Conclusion

The prevalence of PSD seems equally high even if the ischemic stroke is mild, which calls for great concern from clinicians. In addition, our study found that a higher level of indirect bilirubin can lower the risk of PSD. This finding may provide a potential new approach to PSD treatment. Furthermore, the nomogram including bilirubin is convenient and practical to predict PSD after MAIS onset.

Fraxetin attenuates disrupted behavioral and central neurochemical activity in a model of chronic unpredictable stress

Purpose: Chronic unpredictable stress (CUS) induces long-term neuronal and synaptic plasticity with a neurohormonal disbalance leading to the development of co-existing anxiety, depression, and cognitive decline. The side effects and delayed onset of current clinically used antidepressants has prompted a quest for antidepressants with minimum drawbacks. Fraxetin is a natural coumarin derivative with documented antioxidant and neuroprotective activity though its effects on stress are unknown. This study therefore aimed to investigate any possible acute effect of fraxetin in behavioral tests including a CUS paradigm in correlation with brain regional neurochemical changes. Methods: Mice were subjected to a series of mild stressors for 14 days to induce CUS. Furthermore, behavioral performance in the open field test, forced swim test (FST), Y-maze and elevated plus-maze were evaluated. Postmortem frontal cortical, hippocampal and striatal tissues were analyzed via high-performance liquid chromatography (HPLC) for neurochemical changes. Result: Acute administration of fraxetin (20-60 mg/kg, orally) decreased depression-like behavior in the FST and behavioral anxiety in both the open field test and elevated plus-maze. Memory deficits induced during the CUS paradigm were markedly improved as reflected by enhanced Y maze performance. Concurrent biochemical and neurochemical analyses revealed that only the two higher fraxetin doses decreased elevated serum corticosterone levels while diminished serotonin levels in the frontal cortex, striatum and hippocampus were reversed, though noradrenaline was only raised in the striatum. Concomitantly, dopamine levels were restored by fraxetin at the highest dose exclusively in the frontal cortex. Conclusion: Acute treatment with fraxetin attenuated CUS-induced behavioral deficits, ameliorated the increased corticosterone level and restored altered regional neurotransmitter levels and this may indicate a potential application of fraxetin in the management of anxiety and depression modeled by CUS. However, further studies are warranted regarding the chronic effects of fraxetin behaviorally and neurochemically.

Tanshinone IIA ameliorates chronic unpredictable mild stress-induced depression-like behavior and cognitive impairment in rats through the BDNF/TrkB/GAT1 signaling pathway

BACKGROUND

Depression is a common disorder with a complex pathogenesis. Tanshinone IIA (TAN IIA) is a botanical agent with neuroprotective and antidepressant properties.

OBJECTIVE

To examine the effects of TAN IIA on chronic unpredictable mild stress (CUMS)-induced depression-like behavior and cognitive impairment in rats.

METHODS

Rats were exposed to CUMS for 4 weeks, followed by the oral administration of TAN IIA, Deanxit (DEAN), or normal saline for an additional 4 weeks. The control rats were fed with regular chow and administered with normal saline for 4 weeks. Behavioral tests were performed to assess the effects of TAN IIA on depression-like behavior and cognitive impairment in rats with CUMS. The morphology of dendrites was analyzed by Golgi staining. Immunofluorescence staining was performed to determine protein localization.

RESULTS

TAN IIA treatment ameliorated CUMS-induced depression-like behavior and cognitive impairment in rats. TAN IIA treatment also reversed the effects of CUMS on dendritic complexity and the levels of gamma-aminobutyric acid (GABA) in the hippocampus and prefrontal cortex. Rats with CUMS showed decreased levels of brain-derived neurotrophic factor (BDNF) and phosphorylated tropomyosin receptor kinase B (TrkB), upregulated expression of GABA transporter 1 (GAT1), and reduced expression of synaptic proteins in the hippocampus, while TAN IIA treatment significantly diminished the effects of CUMS exposure. In addition, GAT1 was colocalized with N-methyl-D-aspartate receptor 2B.

CONCLUSION

TAN IIA ameliorates CUMS-induced depression-like behavior and cognitive impairment in rats by regulating the BDNF/TrkB/GAT1 signaling pathway, suggesting that TAN IIA may be a candidate drug for the treatment of depression.

Involvement of regulation of the excitation:inhibition functional balance in the mPFC in the antidepressant-anxiolytic effect of YL-IPA08, a novel TSPO ligand

TSPO, an 18 kDa translocator protein, has received increased attention due to its antidepressant-anxiolytic effects. The balance between glutamatergic and GABAergic (E: I) in the medial prefrontal cortex (mPFC) is crucial for antidepressant-anxiolytic effects. However, no evidence is available to clarify the relationship between TSPO and E:I balance. In the present study, we used the TSPO global-knockout (KO) and TSPO wild-type (WT) mice to assess the effects of TSPO on antidepressant-anxiolytic effects of YL-IPA08 (a novel TSPO ligand) and the underlying neurobiological mechanism. Additionally, a multichannel electrophysiological technique was used to explore the effects of YL-IPA08 on pyramidal neurons and interneurons in mPFC. Open field test (OFT) and elevated plus maze (EPM) test revealed that a single dose of YL-IPA08 (0.3 mg/kg, i.p.) exhibited significant anxiolytic actions in WT mice except in KO mice. In only WT mice, significant antidepressant effects were observed in tail suspension test (TST) and forced swim test (FST). The multichannel electrophysiological technique demonstrated that YL-IPA08 significantly increased the firing rates of pyramidal neurons and decreased those of interneurons. Further studies illustrated that the firing rates of glutamatergic might be antagonized by PK11195 (a classic TSPO antagonist). Our results suggest that YL-IPA08 might regulate the E:I balance in mPFC, mediated by TSPO. In summary, TSPO regulates E:I functional balance in mPFC, play a critical role in antidepressant-anxiolytic effects of YL-IPA08, and provide a potential target site for the development of antidepressant and anxiolytic drugs.

Ferulic acid: An extraordinarily neuroprotective phenolic acid with anti-depressive properties

BACKGROUND

Depression, one of the most common mental illnesses and mood disorder syndromes, can seriously harm physical and mental health. As the pathophysiology of depression remains unclear, there is a need to find novel therapeutic agents. Ferulic acid (FA), a phenolic compound found in various Chinese herbal medicines, has anti-inflammatory and free radical scavenging properties as well as a wide range of therapeutic effects against depression.

PURPOSE

In this review, we appraised preclinical research to fully discuss the anti-depression capacity of FA and discussed FAs' holistic characteristics that can contribute to better management of depression.

STUDY DESIGN

We reviewed the results of in vitro and in vivo experiments using FA to treat depression and explored the possible antidepressant pharmacological mechanisms of FA for the clinical treatment of depression.

METHODS

Electronic databases, including PubMed, Google Scholar, and China National Knowledge Infrastructure, were searched from the beginning of the database creation to December 2021.

RESULTS

Studies on the antidepressant effects of FA show that it may exert such effects through various mechanisms. These include the following: the regulation of monoamine and non-monoamine neurotransmitter levels, inhibition of hypothalamic-pituitary-adrenal axis hyperfunction and neuroinflammation, promotion of hippocampal neurogenesis and upregulation brain-derived neurotrophic factor level, neuroprotection (inhibition of neuroinflammation, oxidative stress, mitochondrial dysfunction, and apoptosis), and downregulation of oxidative stress.

CONCLUSION

Preclinical studies on the antidepressant effects of FA were reviewed in this study, and research on the antidepressant mechanisms of FA was summarized, confirming that FA can exert antidepressant effects through various pharmacological mechanisms. However, more multicenter clinical case-control studies are needed to confirm the clinical efficacy of FA.

SSRI antidepressants differentially modulate serotonin reuptake and release in Drosophila

Selective serotonin reuptake inhibitor (SSRI) antidepressants are commonly prescribed treatments for depression, but their effects on serotonin reuptake and release are not well understood. Drosophila melanogaster, the fruit fly, expresses the serotonin transporter (dSERT), the major target of SSRIs, but real-time serotonin changes after SSRIs have not been characterized in this model. The goal of this study was to characterize effects of SSRIs on serotonin concentration and reuptake in Drosophila larvae. We applied various doses (0.1-100 μM) of fluoxetine (Prozac), escitalopram (Lexapro), citalopram (Celexa), and paroxetine (Paxil), to ventral nerve cord (VNC) tissue and measured optogenetically-stimulated serotonin release with fast-scan cyclic voltammetry (FSCV). Fluoxetine increased reuptake from 1 to 100 μM, but serotonin concentration only increased at 100 μM. Thus, fluoxetine occupies dSERT and slows clearance but does not affect concentration. Escitalopram and paroxetine increased serotonin concentrations at all doses, but escitalopram increased reuptake more. Citalopram showed lower concentration changes and faster reuptake profiles compared with escitalopram, so the racemic mixture of citalopram does not change reuptake as much as the S-isomer. Dose response curves were constructed to compare dSERT affinities and paroxetine showed the highest affinity and fluoxetine the lowest. These data demonstrate SSRI mechanisms are complex, with separate effects on reuptake or release. Furthermore, dynamic serotonin changes in Drosophila are similar to previous studies in mammals. This work establishes how antidepressants affect serotonin in real-time, which is useful for future studies that will investigate pharmacological effects of SSRIs with different genetic mutations in Drosophila.

The microbiota-gut-brain axis and its modulation in the therapy of depression: comparison of efficacy of conventional drugs and traditional Chinese medicine approaches

Depression is a common and severe mental disease that places a heavy burden on human society, which can lead to decreased cognitive function, energy loss, insomnia, and even suicide. Although medication plays an important role in improving the symptoms of depression, approximately one third of people with depression do not significantly benefit from medication and experience various adverse reactions. Recently, increasing evidence has shown that gut microbes play an important role in the occurrence and development of depression. There have been illuminating studies previously conducted on the relationship between antidepressant chemicals, traditional Chinese medicine, and the microbiota-gut-brain axis (MGBA). Therefore, in this review, we summarize the role of the MGBA in the occurrence and development of depression, especially the important role of the MGBA in the mechanism of action of antidepressants. Modulation of the MGBA is proposed to enhance the efficacy of antidepressant drugs and reduce their side effects and disease recurrence, so as to provide a new method for the treatment of depression.

Glioma‑neuronal interactions in tumor progression: Mechanism, therapeutic strategies and perspectives (Review)

An increasing body of evidence has become available to reveal the synaptic and functional integration of glioma into the brain network, facilitating tumor progression. The novel discovery of glioma-neuronal interactions has fundamentally challenged our understanding of this refractory disease. The present review aimed to provide an overview of how the neuronal activities function through synapses, neurotransmitters, ion channels, gap junctions, tumor microtubes and neuronal molecules to establish communications with glioma, as well as a simplified explanation of the reciprocal effects of crosstalk on neuronal pathophysiology. In addition, the current state of therapeutic avenues targeting critical factors involved in glioma-euronal interactions is discussed and an overview of clinical trial data for further investigation is provided. Finally, newly emerging technologies, including immunomodulation, a neural stem cell-based delivery system, optogenetics techniques and co-culture of neuron organoids and glioma, are proposed, which may pave a way towards gaining deeper insight into both the mechanisms associated with neuron- and glioma-communicating networks and the development of therapeutic strategies to target this currently lethal brain tumor.

New monoamine antidepressant, hypidone hydrochloride (YL-0919), enhances the excitability of medial prefrontal cortex in mice via a neural disinhibition mechanism

Hypidone hydrochloride (YL-0919) is a novel antidepressant in clinical phase II trial. Previous studies show that YL-0919 is a selective 5-HT (serotonin) reuptake inhibitor, 5-HT_1A receptor partial agonist, and 5-HT₆ receptor agonist, which exerts antidepressant effects in various animal models, but its effects on neural function remain unclear. Medial prefrontal cortex (mPFC), a highly evolved brain region, controls highest order cognitive functions and emotion regulation. In this study we investigated the effects of YL-0919 on the mPFC function, including the changes in neuronal activities using electrophysiological recordings. Extracellular recording (in vivo) showed that chronic administration of YL-0919 significantly increased the spontaneous discharges of mPFC neurons. In mouse mPFC slices, whole-cell recording revealed that perfusion of YL-0919 significantly increased the frequency of sEPSCs, but decreased the frequency of sIPSCs. Then we conducted whole-cell recording in mPFC slices of GAD67-GFP transgenic mice, and demonstrated that YL-0919 significantly inhibited the excitability of GABAergic neurons. In contrast, it did not alter the excitability of pyramidal neurons in mPFC slices of normal mice. Moreover, the inhibition of GABAergic neurons by YL-0919 was prevented by pre-treatment with 5-HT_1A receptor antagonist WAY 100635. Finally, chronic administration of YL-0919 significantly increased the phosphorylation levels of mTOR and GSK-3β in the mPFC as compared with vehicle. Taken together, our results demonstrate that YL-0919 enhances the excitability of mPFC via a disinhibition mechanism to fulfill its rapid antidepressant neural mechanism, which was accomplished by 5-HT_1A receptor-mediated inhibition of inhibitory GABAergic interneurons.

Sigma-1 Receptors in Depression: Mechanism and Therapeutic Development

Depression is the most common type of neuropsychiatric illness and has increasingly become a major cause of disability. Unfortunately, the recent global pandemic of COVID-19 has dramatically increased the incidence of depression and has significantly increased the burden of mental health care worldwide. Since full remission of the clinical symptoms of depression has not been achieved with current treatments, there is a constant need to discover new compounds that meet the major clinical needs. Recently, the roles of sigma receptors, especially the sigma-1 receptor subtype, have attracted increasing attention as potential new targets and target-specific drugs due to their translocation property that produces a broad spectrum of biological functions. Even clinical first-line antidepressants with or without affinity for sigma-1 receptors have different pharmacological profiles. Thus, the regulatory role of sigma-1 receptors might be useful in treating these central nervous system (CNS) diseases. In addition, long-term mental stress disrupts the homeostasis in the CNS. In this review, we discuss the topical literature concerning sigma-1 receptor antidepressant mechanism of action in the regulation of intracellular proteostasis, calcium homeostasis and especially the dynamic Excitatory/Inhibitory (E/I) balance in the brain. Furthermore, based on these discoveries, we discuss sigma-1 receptor ligands with respect to their promise as targets for fast-onset action drugs in treating depression.

Integrating Network Pharmacology and In Vivo Model to Investigate the Mechanism of Biheimaer in the Treatment of Functional Dyspepsia

Objective. Biheimaer (BHM) is a hospital formulation for clinical treatment of dyspepsia and acid reflux, based on Compatibility Theory of Traditional Chinese Medicine. This study anticipated to elucidate the molecular mechanism of BHM against Functional dyspepsia via combined network pharmacology prediction with experimental verification. Methods. Based on network pharmacology, the potential active components and targets of BHM in the treatment of functional dyspepsia were explored by prediction and molecular docking technology. The results of protein–protein interaction analysis, functional annotation, and pathway enrichment analysis further refined the main targets and pathways. The molecular mechanism of BHM improving functional dyspepsia mice induced by L-arginine + atropine was verified on the basis of network pharmacology. Results. In this study, 183 effective compounds were screened from BHM; moreover, 1007 compound-related predicted targets and 156 functional dyspepsia-related targets were found. The results of enrichment analysis and in vivo experiments showed that BHM could regulate intestinal smooth muscle contraction to play a therapeutic role in functional dyspepsia by reducing the expression of NOS3, SERT, TRPV1, and inhibiting the inflammatory cytokine (IL-1β, TNF-α) to intervene the inflammatory response in mice. Conclusions. This study revealed the molecular biological mechanisms of the Traditional Chinese Medicine formulation of BHM in functional dyspepsia by network pharmacology and experimental verification, meanwhile provided scientific support for subsequent clinical medication.