Geniposide protects depression through BTK/JAK2/STAT1 signaling pathway in lipopolysaccharide-induced depressive mice

The effects of Shaoma Zhijing granules and its main components on Tourette syndrome

BACKGROUND

Tourette syndrome (TS) represents a neurodevelopmental disorder characterized by an uncertain etiology and influencing factors. Frequently, it co-occurs with conditions such as attention deficit hyperactivity disorder, obsessive-compulsive disorder, and sleep disturbances, which have garnered substantial attention from the research community in recent years. Clinical trials have demonstrated that Shaoma Zhijing Granules (SMZJG, 5-ling granule, also known as TSupport or T92 under U.S. development), a traditional Chinese medicine compound, is an effective treatment for TS.

PURPOSE

To conduct scientometric analysis on developing trends, research countries and institutions, current status, hot spots of TS and discuss the underlying mechanisms of SMZJG and its main components on TS. The aim is to provide valuable reference for ongoing clinical and basic research on TS and SMZJG.

STUDY DESIGN & METHODS

Using Tourette syndrome, SMZJG and its main components along with their synonyms as keywords, we conducted a comprehensive search across major scientific databases including the Web of Science Core Collection, PubMed and China National Knowledge Infrastructure (CNKI) databases. A total of 5952 references and 99 patents were obtained. Among these, 5039 articles and reviews, as well as 54 patents were analyzed by Citespace and VOSviewer software.

RESULTS

The available evidence indicates that the SMZJG's components likely exert their mechanisms in treating TS by regulating the dopaminergic pathway system, neurotransmitter imbalances, reducing neuroinflammation, promoting the repair of nerve damage and improving sleep disorders.

CONCLUSION

This comprehensive analysis lays the foundation for an extensive exploration of the feasibility and clinical applications of SMZJG in TS treatment.

The miR-23b-3p from adipose-derived stem cell exosomes alleviate inflammation in mice experiencing kainic acid-induced epileptic seizures

Epilepsy is a common neurologic disorder. While a good clinical solution is still missing, studies have confirmed that exosomes (Exos) derived from adipose-derived stem cells (ADSCs) had a therapeutic effect on various diseases, including neurological diseases. Therefore, this study aimed to reveal whether ADSC-Exo treatment could improve kainic acid (KA)-induced seizures in epileptic mice. ADSCs and Exos were isolated. Mice were generated with KA-induced epileptic seizures. ELISA was used to detect inflammatory factor expression. Luciferase reporter analysis detection showed a relationship among miR-23b-3p, STAT1, and glyoxylate reductase 1 (GlyR1). ADSC-Exos had a protective effect on KA-induced seizures by inhibiting inflammatory factor expression and the M1 microglia phenotype. The result showed that miR-23b-3p played an important role in the Exo-mediated protective effect in KA-induced seizures in epileptic mice by regulating STAT1 and GlyR1. Luciferase reporter analysis confirmed that miR-23b-3p interacted with the 3'-UTR of STAT1 and GlyR1. The miR-23b-3p inhibited M1 microglia-mediated inflammatory factor expression in microglial cells by regulating STAT1 and GlyR1. The downregulation of miR-23b-3p decreased the protective effect of ADSC-Exos on KA-induced seizures in epileptic mice. The miR-23b-3p from ADSC-Exos alleviated inflammation in mice with KA-induced epileptic seizures.

Mitochondrial calcium uniporter knockdown in hippocampal neurons alleviates anxious and depressive behavior in the 3XTG Alzheimer's disease mouse model

Alzheimer's disease (AD) is a progressive and degenerative disorder accompanied by emotional disturbance, especially anxiety and depression. More and more evidence shows that the imbalance of mitochondrial Ca2+ (mCa2+) homeostasis has a close connection with the pathogenesis of anxiety and depression. The Mitochondrial Calcium Uniporter (MCU), a key channel of mCa2+ uptake, induces the imbalance of mCa2+ homeostasis and may be a therapeutic target for anxiety and depression of AD. In the present study, we revealed for the first time that MCU knockdown in hippocampal neurons alleviated anxious and depressive behaviors of APP/PS1/tau mice through elevated plus-maze (EPM), elevated zero maze (EZM), sucrose preference test (SPT) and tail suspension test (TST). Western blot analysis results demonstrated that MCU knockdown in hippocampal neurons increased levels of glutamate decarboxylase 67 (GAD67), vesicular GABA transporter (vGAT) and GABAA receptor α1 (GABRA1) and activated the PKA-CREB-BDNF signaling pathway. This study indicates that MCU inhibition has the potential to be developed as a novel therapy for anxiety and depression in AD.

Gastrodin ameliorates depressive-like behaviors via modulating gut microbiota in CUMS-induced mice

PURPOSE

Depression is a psychiatric disorder and the treatment of depression is an urgent problem that need to be solved. Gastrodin (GAS) is a Traditional Chinese Medicine from an orchid and is used for neurological diseases, including depressive disorders.

METHODS

To assess the effect of GAS on gut microbiota of depressive mice, we established a chronic unpredictable mild stress (CUMS)-induced mouse model, and GAS was administered to one group of the mice. Animal behavior experiments were used to detect depressive-like behaviors, and 16 S rRNA gene analysis was applied to detect the gut microbiota of each group. All raw sequences were deposited in the NCBI Sequence Read Archive under accession number SRP491061.

RESULTS

GAS treatment significantly improved depressive-like behaviors as well as the diversity and abundance of the gut microbiota. The depressive-like behaviors of the CUMS-GAS group were improved in different degrees compared with the CUMS group. The linear discriminant analysis (LDA) of the gut microbiota showed that the makeup of the gut microbiota in mice changed dramatically in the CUMS-GAS group, compared with the CUMS group, Bacteroides (LDA = 3.94, P < 0.05) were enriched in the CUMS-GAS group at the genus level. In comparison to the CUMS group, the CUMS-GAS group had a greater concentration numbers of Lactobacillus, Corynebacterium, Staphylococcus, Bacteroides, Psychrobacter, and Alistipes.

CONCLUSION

Our results suggested that GAS improved depressive-like behaviors in mice and impacted the microbial composition of the gut. Our research indicated that dysbiosis of the gut microbiota may be affected by GAS treatment, which improved depressive-like behaviors in the CUMS-induced mouse model of depression.

Targeting autophagy to counteract neuroinflammation: A novel antidepressant strategy

Depression is a common disease that affects physical and mental health and imposes a considerable burden on afflicted individuals and their families worldwide. Depression is associated with a high rate of disability and suicide. It causes a severe decline in productivity and quality of life. Unfortunately, the pathophysiological mechanisms underlying depression have not been fully elucidated, and the risk of its treatment is still presented. Studies have shown that the expression of autophagic markers in the brain and peripheral inflammatory mediators are dysregulated in depression. Autophagy-related genes regulate the level of autophagy and change the inflammatory response in depression. Depression is related to several aspects of immunity. The regulation of the immune system and inflammation by autophagy may lead to the development or deterioration of mental disorders. This review highlights the role of autophagy and neuroinflammation in the pathophysiology of depression, sumaries the autophagy-targeting small moleculars, and discusses a novel therapeutic strategy based on anti-inflammatory mechanisms that target autophagy to treat the disease.

Neuropharmacological insights into Gardenia jasminoides Ellis: Harnessing therapeutic potential for central nervous system disorders

BACKGROUND

In China, Gardenia jasminoides Ellis (GJE) has a longstanding history of application. The Ministry of Health has listed it as one of the first pharmaceutical or food resources. In ethnic, traditional, and folk medicine, GJE has been used to treat fever and cold and relieve nervous anxiety. Recent studies have confirmed the significant efficacy of GJE for treating central nervous system (CNS) disorders, including Alzheimer's disease, Parkinson's disease, and major depressive disorder; however, GJE has not been systematically evaluated.

PURPOSE

This research systematically summarizes global studies on the use of GJE for treating CNS disorders and explores the potential applications and underlying mechanisms via intestinal flora analysis and network pharmacology, aiming to establish a scientific basis for innovative CNS disorder treatment with GJE.

METHODS

The PRISMA guidelines were used, and electronic databases such as the Web of Science, PubMed, and China National Knowledge Infrastructure were searched using the following search terms: "Gardenia jasminoides Ellis" with "central nervous system disease," "neuroprotection," "Alzheimer's disease," "Parkinson's disease," "ischemic stroke," "Epilepsy," and "major depressive disorder." The published literature up to September 2023 was searched to obtain relevant information on the application of GJE for treating CNS disorders.

RESULTS

There has been an increase in research on the material formulation and mechanisms of action of GJE for treating CNS disorders, with marked effects on CNS disorder treatment in different countries and regions. We summarized the research results related to the role of GJE in vitro and in vivo via multitargeted interventions in response to the complex mechanisms of action of CNS disorders.

CONCLUSION

We systematically reviewed the research progress on traditional treatment for GJE and preclinical mechanisms of CNS disorders and explored the potential of optimizing network pharmacology strategies and intestinal flora analysis to elucidate the mechanisms of action of GJE. The remarkable therapeutic efficacy of GJE, an important resource in traditional medicine, has been well documented in the literature, highlighting its significant medicinal potential.

Geniposide improves depression-like behavior in prenatal stress male offspring through restoring HPA axis- and glucocorticoid receptor-associated dysfunction

AIMS

Prenatal stress (PS) has an important impact on the brain development of offspring, which can lead to attention deficits, anxiety and depression in offspring. Geniposide (GE) is a kind of iridoid glycoside extracted from Gardenia jasminoides Ellis. It has various pharmacological effects and has been proved that have antidepressant effects. The aim of this study was to investigate the effect of GE on depression-like behavior in PS-induced male offspring mice and explore the possible molecular mechanisms.

METHODS

We used a prenatal restraint stress model, focusing on male PS-induced offspring mice to study the effects of GE.

KEY FINDINGS

The results showed that GE administration for 4 weeks significantly improved the depression-like behavior in PS offspring mice, which was manifested by markedly increasing the sucrose preference of PS offspring and the activity in the open field test, and reducing the immobility time in the forced swimming test. In addition, GE significantly reduced the levels of hypothalamic-pituitary-adrenal (HPA) axis-related hormones and exceedingly increased the protein expression of MAP2 and GAP43 in PS offspring. Furthermore, GE increased Glucocorticoid receptors (GR) nuclear translocation in the hippocampus of PS offspring, and enhanced the expression of synaptic plasticity-related proteins.

CONCLUSION

The results of this study showed that GE exerts antidepressant effects in male PS offspring mice by regulating the HPA axis, GR function and proteins related to synaptic plasticity.

A comprehensive review of ethnopharmacology, chemical constituents, pharmacological effects, pharmacokinetics, toxicology, and quality control of gardeniae fructus

ETHNOPHARMACOLOGICAL RELEVANCE

Gardeniae Fructus (GF), the desiccative mature fruitage of Gardenia jasminoides J. Ellis (G. jasminoides), belongs to the Rubiaceae family. It has abundant medicinal value, such as purging fire and eliminating annoyance, clearing heat and diuresis, cooling blood, and detoxifying. GF is usually used in combination with other drugs to treat diseases such as fever and jaundice in damp heat syndrome in traditional Chinese medicines (TCMs) clinical practice.

THE AIM OF THE REVIEW

This review comprehensively summarizes the research progress in botany, traditional medical use, processing method, phytochemistry, pharmacological activity, quality control, pharmacokinetics, and toxicology, which aims to provide a scientific basis for the rational application and future research of GF.

MATERIALS AND METHODS

ScienceDirect, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), Embase, Scopus etc. databases were retrieved to gain the comprehensive information of GF.

RESULTS

At present, more than 215 compounds were isolated and identified from GF, including iridoids, diterpenes, triterpenoids, flavonoids, organic esters, and so on. The traditional application of GF mainly focused on clearing heat and detoxification. Pharmacological studies proved that GF had anti-inflammatory, antioxidation, antifatigue, antithrombotic, liver and gallbladder protection, and other pharmacological effects. In addition, many improved processing methods can alleviate the side effects and toxic reactions caused by long-term use of GF, so controlling its quality through multi-component content measurement has become an important means of research.

CONCLUSION

GF has a wide range of applications, the mechanisms by which some effective substances exert their pharmacological effects have not been clearly explained due to the complexity and diversity of its components. This review systematically elaborates on the traditional medical use, processing method, phytochemistry, pharmacological activity, quality control, and toxicology of GF, and it is expected to become a candidate drug for treating diseases, such as depression, pancreatitis, alcoholic or non-alcoholic fatty liver.

TREM2 regulates BV2 microglia activation and influences corticosterone-induced neuroinflammation in depressive disorders

Depressive disorders is a serious mental illness, and its underlying pathological mechanisms remain unclear. The overactivation of microglia and neuroinflammation are thought to play an essential role in the occurrence and development of depressive disorders. TREM2, an immune protein mainly expressed in microglia, is an important part of nerve cells involved in inflammatory response. Corticosterone (CORT) is often referred to as a stress hormone and plays a role in the immune system and stress response. Therefore, this study investigated the role of TREM2 in CORT-induced BV2 cell damage and preliminarily analyzed the effects of TREM2 on JAK2/STAT3 signaling pathway and microglia polarization. The cell model of CORT-induced depression in vitro was established, and the effect of CORT on the activity of BV2 microglia was detected by CCK8. Plasmid transfection was used to overexpress and interfere with TREM2 in BV2 cells cultured by CORT. Western blotting, PCR, and ELISA analyzed the expression of related proteins and inflammatory factors. The results showed that CORT could affect BV2 cell proliferation and TREM2 levels. In the presence of CORT, overexpression of TREM2 decreased the levels of TNF-α, IL-1β, and IL-6 and increased the levels of IL-10. Interference with TREM2 increased the levels of TNF-α, IL-1β, and IL-6 and decreased the levels of IL-10. TREM2 can affect the release of inflammatory factors through the JAK2/STAT3 signaling pathway and regulate the M1/M2 phenotypic transformation of microglia. TREM2 plays a role in regulating CORT-induced inflammatory responses, revealing the influence of TREM2 on the neuroinflammatory pathogenesis of depressive disorders and suggesting that TREM2 may be a new target for the prevention and treatment of depressive disorders.

DHA and EPA Alleviate Epileptic Depression in PTZ-Treated Young Mice Model by Inhibiting Neuroinflammation through Regulating Microglial M2 Polarization and Improving Mitochondrial Metabolism

Depression is the most common complication of childhood epilepsy, leading to a poor prognosis for seizure control and poor quality of life. However, the molecular mechanisms underlying epileptic depression have not been completely elucidated. Increasing evidence suggests that oxidative stress and neuroinflammation are major contributors to depression. The positive effects of dietary supplementation with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on depression have been previously reported. However, knowledge regarding the effects of EPA and DHA in managing depressive symptoms in pediatric patients with epilepsy is limited. Therefore, this study aims to investigate the effects of EPA and DHA on epileptic depression in a pentylenetetrazole (PTZ)-treated young mouse model. Three-week-old mice were fed a DHA- or EPA-enriched diet for 21 days and treated with PTZ (35 mg/kg, i.p.) every other day for a total of 10 times. EPA was more effective than DHA at alleviating PTZ-induced depressive symptoms. Pathological results revealed that DHA and EPA significantly improved neuronal degeneration in the hippocampus. Analysis of the mechanism revealed that DHA and EPA mitigated PTZ-induced myelin damage by increasing the protein levels of CNPase, Olig2, and MBP. Furthermore, both DHA and EPA reduced neuroinflammation by promoting microglial M2 polarization and suppressing the LCN2-NLRP3 inflammasome pathway. Notably, EPA polarized microglia towards the M2 phenotype. In addition, DHA and EPA decreased oxidative stress by inhibiting NOX2 and enhancing mitochondrial metabolism through the increased expression of mitochondrial respiratory chain complex I-V proteins. These findings suggest that DHA and EPA can be used as effective interventions to improve depression in children with epilepsy, with EPA being a particularly favorable option.

Sertraline associated with gold nanoparticles reduce cellular toxicity and induce sex-specific responses in behavior and neuroinflammation biomarkers in a mouse model of anxiety

This study aimed to evaluate the effects of sertraline associated with gold nanoparticles (AuNPs) in vitro cell viability and in vivo behavior and inflammatory biomarkers in a mouse model of anxiety. Sertraline associated with AuNPs were synthesized and characterized. For the in vitro study, NIH3T3 and HT-22 cells were treated with different doses of sertraline, AuNPs, and sertraline + AuNPs and their viability was evaluated using the MTT assay. For the in vivo study, pregnant Swiss mice were administered a single dose of lipopolysaccharide (LPS) on the ninth day of gestation. The female and male offspring were divided into five treatment groups on PND 60 and administered chronic treatment for 28 days. The animals were subjected to behavioral testing and were subsequently euthanized. Their brains were collected and analyzed for inflammatory biomarkers. Sertraline associated with AuNPs exhibited significant changes in surface characteristics and increased diameters. Different doses of sertraline + AuNPs showed higher cell viability in NIH3T3 and HT-22 cells compared with sertraline alone. The offspring of LPS-treated dams exhibited anxiety-like behavior and neuroinflammatory biomarker changes during adulthood, which were ameliorated via sertraline + AuNPs treatment. The treatment response was sex-dependent and brain region-specific. These results suggest that AuNPs, which demonstrate potential to bind to other molecules, low toxicity, and reduced inflammation, can be synergistically used with sertraline to improve drug efficacy and safety by decreasing neuroinflammation and sertraline toxicity.

Gardenia (Gardenia jasminoides Ellis) fruit: a critical review of its functional nutrients, processing methods, health-promoting effects, comprehensive application and future tendencies

Gardenia fruit (GF) is the mature fruit of Gardenia jasminoides Ellis, boasting a rich array of nutrients and phytochemicals. Over time, GF has been extensively utilized in both food and medicinal contexts. In recent years, numerous studies have delved into the chemical constituents of GF and their associated pharmacological activities, encompassing its phytochemical composition and health-promoting properties. This review aims to provide a critical and comprehensive summary of GF research, covering nutrient content, extraction technologies, and potential health benefits, offering new avenues for future investigations and highlighting its potential as an innovative food resource. Additionally, the review proposes novel industrial applications for GF, such as utilizing gardenia yellow/red/blue pigments in the food industry and incorporating it with other herbs in traditional Chinese medicine. By addressing current challenges in developing GF-related products, this work provides insights for potential applications in the cosmetics, food, and health products industries. Notably, there is a need for the development of more efficient extraction methods to harness the nutritional components of GF fully. Further research is needed to understand the specific molecular mechanisms underlying its bioactivities. Exploring advanced processing techniques to create innovative GF-derived products will show great promise for the future.

Preparative separation of iridoid glucosides and crocins from Gardeniae Fructus using sequential macroporous resin column chromatography and evaluation of their anti-inflammatory and antioxidant activities

Iridoid glycosides (geniposide (GP), genipin-1-gentiobioside (GB), etc.) and crocins (crocin Ⅰ (CR1), crocin Ⅱ(CR2), etc.) are two main bioactive components in Gardeniae Fructus (GF), which is a famous traditional Chinese medicine. Iridoid glycosides exhibit many activities and are used to manufacture gardenia blue pigment for the food industry. Crocins are rare natural water-soluble carotenoids that are often used as food colorants. A sequential macroporous resin column chromatography technology composed of HC-500B and HC-900B resins was developed to selectively separate iridoid glucosides and crocins from GF. The adsorption of GP on HC-900B resin was an exothermic process. The adsorption of CR1 on HC-500B resin was an endothermic process. The two kinds of components were completely separated by a sequential resin column. GB and GP were mainly found in product 1 (P1) with purities of 11.38% and 46.83%, respectively, while CR1 and CR2 were mainly found in product 2 (P2) with purities of 12.32% and 1.40%, respectively. The recovery yields of all the compounds were more than 80%. The above results showed that sequential resin column chromatography technology achieved high selectivity and recovery yields. GF extract, P1 and P2 could significantly inhibit the secretion of nitric oxide (NO), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-induced RAW264.7 cells, indicating that iridoid glycosides and crocins provide a greater contribution to the anti-inflammatory activity of GF. At the same time, compared to the GF extract and P1, P2 exhibited stronger scavenging activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, indicating that crocins may provide a significant contribution to the antioxidant activity of GF.

CD200 in dentate gyrus improves depressive-like behaviors of mice through enhancing hippocampal neurogenesis via alleviation of microglia hyperactivation

BACKGROUND

Neuroinflammation and microglia play critical roles in the development of depression. Cluster of differentiation 200 (CD200) is an anti-inflammatory glycoprotein that is mainly expressed in neurons, and its receptor CD200R1 is primarily in microglia. Although the CD200-CD200R1 pathway is necessary for microglial activation, its role in the pathophysiology of depression remains unknown.

METHODS

The chronic social defeat stress (CSDS) with behavioral tests were performed to investigate the effect of CD200 on the depressive-like behaviors. Viral vectors were used to overexpress or knockdown of CD200. The levels of CD200 and inflammatory cytokines were tested with molecular biological techniques. The status of microglia, the expression of BDNF and neurogenesis were detected with immunofluorescence imaging.

RESULTS

We found that the expression of CD200 was decreased in the dentate gyrus (DG) region of mice experienced CSDS. Overexpression of CD200 alleviated the depressive-like behaviors of stressed mice and inhibition of CD200 facilitated the susceptibility to stress. When CD200R1 receptors on microglia were knocked down, CD200 was unable to exert its role in alleviating depressive-like behavior. Microglia in the DG brain region were morphologically activated after exposure to CSDS. In contrast, exogenous administration of CD200 inhibited microglia hyperactivation, alleviated neuroinflammatory response in hippocampus, and increased the expression of BDNF, which in turn ameliorated adult hippocampal neurogenesis impairment in the DG induced by CSDS.

CONCLUSIONS

Taken together, these results suggest that CD200-mediated alleviation of microglia hyperactivation contributes to the antidepressant effect of neurogenesis in dentate gyrus in mice.

Lipopolysaccharide-induced depression-like model in mice: meta-analysis and systematic evaluation

Depression is a complex and biologically heterogeneous disorder. Recent studies have shown that central nervous system (CNS) inflammation plays a key role in the development of depression. Lipopolysaccharide (LPS)-induced depression-like model in mice is commonly used to studying the mechanisms of inflammation-associated depression and the therapeutic effects of drugs. Numerous LPS-induced depression-like models in mice exist and differ widely in animal characteristics and methodological parameters. Here, we systematically reviewed studies on PubMed from January 2017 to July 2022 and performed cardinal of 170 studies and meta-analyses of 61 studies to support finding suitable animal models for future experimental studies on inflammation-associated depression. Mouse strains, LPS administration, and behavioral outcomes of these models have been assessed. In the meta-analysis, forced swimming test (FST) was used to evaluate the effect size of different mouse strains and LPS doses. The results revealed large effect sizes in ICR and Swiss mice, but less heterogeneity in C57BL/6 mice. For LPS intraperitoneal dose, the difference did not affect behavioral outcomes in C57BL/6 mice. However, in ICR mice, the most significant effect on behavioral outcomes was observed after the injection of 0.5 mg/kg LPS. Our results suggests that mice strains and LPS administration play a key role in the evaluation of behavioral outcomes in such models.

Blocking coprophagy increases the levels of inflammation and depression in healthy mice as well as mice receiving fecal microbiota transplantation from disease model mice donors

Rodents have been extensively used as animal models in microbiome studies. However, all rodents have a habitual nature called coprophagy, a phenomenon that they self-reinoculate feces into their gastrointestinal tract. Recent studies have shown that blocking coprophagy can alter rodents' diversity of gut microbiota, metabolism, neurochemistry, and cognitive behavior. However, whether rodents' coprophagy behavior affects the levels of inflammation and depression is unclear. In order to address this problem, we first blocked coprophagy in healthy mice. It displayed an increase in the levels of depression, verified by depressive-like behaviors and mood-related indicators, and inflammation, verified by the increased levels of the pro-inflammatory cytokine, in coprophagy-blocked mice. Furthermore, we transplanted fecal microbiota from chronic restraint stress (CRS) depression model mice and lipopolysaccharide (LPS) inflammation model mice to healthy recipient mice, respectively. It showed that the disease-like phenotypes in the coprophagy-blocked group were worse than those in the coprophagy-unblocked group, including severer depressive symptoms and higher levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and IFN-γ) in serum, prefrontal cortex (PFC), and hippocampus (HIP). These findings showed that blocking coprophagy in mice not only increased the levels of inflammation and depression in healthy mice but also aggravated inflammation and depression induced by fecal microbiota from disease donors. The discovery may provide a vital reference for future research involving FMT in rodents.

Antidepressant-like effects of geniposide in chronic unpredictable mild stress-induced mice by regulating the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 networks

Evidence exists suggesting the anti-depressive activities of geniposide (GP), a major compound in Gardenia jasminoides Ellis. Accordingly, the present study attempts to explore the anti-depressive mechanism of GP in chronic unpredictable mild stress (CUMS)-induced depression-like behaviors of mice. CUMS-induced mice were given GP daily and subjected to behavioral tests to observe the effect of GP on the depression-like behaviors. It was noted that GP administration reduced depression-like behaviors in CUMS mice. Transcriptome sequencing was conducted in three control and three CUMS mice. Differentially expressed circRNAs, lncRNAs and mRNAs were then screened by bioinformatics analyses. Intersection analysis of the transcriptome sequencing results with the bioinformatics analysis results was followed to identify the candidate targets. We found that Gata2 alleviated depression-like behaviors via the metabolism- and synapse-related pathways. Gata2 was a target of miR-25-3p, which had binding sites to circ_0008405 and Oip5os1. circ_0008405 and Oip5os1 competitively bound to miR-25-3p to release the expression of Gata2. GP administration ameliorated depression-like behaviors in CUMS mice through regulation of the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 crosstalk networks. Taken together, GP may exert a potential antidepressant-like effect on CUMS mice, which is ascribed to regulation of the circ_0008405/miR-25-3p/Gata2 and Oip5os1/miR-25-3p/Gata2 crosstalk networks.

Quantitative proteomics reveals the therapeutic effects of RFAP against depression via pathway regulation of long-term depression and potentiation

Ethnopharmacological relevance

RFAP is a compound extraction complex of four Traditional Chinese Medicine (TCM), including the dry bark of Paeonia lactiflora Pall. (Radix Paeoniae Alba), Gardenia jasminoides J. Ellis (Fructus Gardeniae), Albizia julibrissin Durazz. (Albizia julibrissin Durazz), and Paeonia × suffruticosa Andrews (Peony bark). Not only RFAP but also the individual ingredients have been commonly used for the treatment of depression in the clinic. However, the underlying mechanism of pharmacology is difficult to interpret since its holistic and multidrug nature.

Aim of the study

This study aimed to elucidate the potential antidepressant mechanism of RFAP in the treatment of chronic unpredictable mild stress (CUMS) rats' model via the quantitative proteomics approach.

Materials and methods

We established the CUMS rats' model and evaluated the efficacy of RFAP using multiple behavior assays, including the sugar preference test, open field test, and forced swimming test. Then label-free quantitative proteomics analyses were performed to evaluate the integrated changes of proteome profiling in control, CUMS, RFAP low dose, and RFAP high dose groups. Finally, we validated the critical changed proteins in the pathways of long-term depression and potentiation via RT-PCR and Western blotting assays.

Results

We successfully established the CUMS rats' model. The behavior assays indicated that the rats demonstrated a tendency to behavioral despair after four weeks. Label-free quantitative proteomics showed that 107 proteins were significantly upregulated and 163 proteins were downregulated in the CUMS group compared to the control group. These differentially expressed proteins were involved in long-term potentiation, long-term depression, nervous system development, neuronal synaptic structural constituent of ribosome, ATP metabolic process, learning or memory, and cellular lipid metabolic process. RFAP treatment partially restored the differentially expressed protein profile. The protective effect of RFAP on behavioral assessment were consistent with the results of proteomics.

Conclusions

The results indicated that RFAP exerted a synergistic effect on CUMS by regulating long-term inhibition and potentiation-related proteins.

Melanin-like polydopamine nanoparticles mediating anti-inflammatory and rescuing synaptic loss for inflammatory depression therapy

Inflammatory depression is closely related to neuroinflammation. However, current anti-inflammatory drugs have low permeability to cross blood-brain barrier with difficulties reaching the central nervous system to provide therapeutic effectiveness. To overcome this limitation, the nano-based drug delivery technology was used to synthesize melanin-like polydopamine nanoparticles (PDA NPs) (~ 250 nm) which can cross the blood-brain barrier. Importantly, PDA NPs with abundant phenolic hydroxyl groups function as excellent free radical scavengers to attenuate cell damage caused by reactive oxygen species or acute inflammation. In vitro experiments revealed that PDA NPs exhibited excellent antioxidative properties. Next, we aimed to investigate the therapeutic effect of PDA NPs on inflammatory depression through intraperitoneal injection to the lipopolysaccharide-induced inflammatory depression model in mice. PDA NPs significantly reversed the depression-like behavior. PDA NPs was also found to reduce the peripheral and central inflammation induced by LPS, showing that alleviated splenomegaly, reduced serum inflammatory cytokines, inhibited microglial activation and restored synaptic loss. Various experiments also showed that PDA NPs had good biocompatibility both in vivo and in vitro. Our work suggested that PDA NPs may be biocompatible nano-drugs in treating inflammatory depression but their clinical application requires further study.

Glutathione S-Transferases Mediate In Vitro and In Vivo Inactivation of Genipin: Implications for an Underlying Detoxification Mechanism

Genipin (GP), the reactive metabolite of geniposide (GE), is responsible for GE-induced hepatotoxicity. As a potential detoxification pathway, the inactivation of GP by glutathione S-transferases (GSTs) has not yet been characterized. In this study, the thiol-GSH conjugates of GP, M532-1 and M532-2 were first identified and the catalytic activities of GSTs were investigated both in vitro and in vivo. GSTA1-1 and GSTA4-4 showed high activity in the formation of both thiol-GSH conjugates, whereas GSTA4-4 specifically catalyzed M532-2 formation in vitro. The active GST isoforms protect against alkylation of N-acetylcysteine (NAC), a classic model nucleophile. GST inhibition attenuated M532-1 formation in rat bile, confirming the in vivo catalytic role of GSTs. In conclusion, this study demonstrated the inactivation of GP by GSTs and implied that interindividual variability of GSTs may be a risk factor for susceptibility to GE-induced hepatotoxicity.

CRHR1 antagonist alleviates LPS-induced depression-like behaviour in mice

BACKGROUND

Maladaptation of the HPA (hypothalamic-pituitary-adrenal) axis plays an important role in depression-like behaviour, but the specific molecular mechanisms are unknown. Here, we determined the roles of CRHR1 (corticotrophin releasing hormone receptor 1) and nectin3 in LPS (lipopolysaccharide)-induced depression-like behaviour in mice.

METHODS

C57BL/6 male mice were intraperitoneally injected with LPS (0.83 g/kg), and the open field, novelty-suppressed feeding, forced swimming, and tail suspension tests were performed after intraperitoneal injections of saline or antalarmin (20 mg/kg). The hippocampal mRNA levels of CRHR1 and nectin3 were determined by quantitative reverse transcription-PCR. The hippocampal protein levels of CRHR1, nectin3, and calbindin were measured by western blotting. The CORT (corticosterone) levels in the blood were measured by ELISA kits.

RESULTS

Antalarmin alleviated LPS-induced depression-like behaviour in male mice. Furthermore, antalarmin significantly inhibited changes in CRHR1, nectin3 and calbindin levels in the hippocampus and reduced the increase in CORT levels in LPS-treated mice.

CONCLUSION

CRHR1antagonist showed antidepressant effects in LPS-induced depressive mice, and CRHR1/nectin3 signalling may play a crucial role in this process.

FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders

Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.

Therapeutic potential of plant iridoids in depression: a review

CONTEXT

Depression is a mental disorder characterized by low mood, reduced interest, impaired cognitive function, and vegetative symptoms such as sleep disturbances or poor appetite. Iridoids are the active constituents in several Chinese classical antidepressant formulae such as Yueju Pill, Zhi-Zi-Hou-Po Decoction, Zhi-Zi-Chi Decoction, and Baihe Dihuang Decoction. Parallel to their wide usages, iridoids are considered potential lead compounds for the treatment of neurological diseases.

OBJECTIVE

The review summarizes the therapeutic potential and molecular mechanisms of iridoids in the prevention or treatment of depression and contributes to identifying research gaps in iridoids as potential antidepressant medication.

METHODS

The following key phrases were sought in PubMed, Google Scholar, Web of Science, and China National Knowledge Internet (CNKI) without time limitation to search all relevant articles with in vivo or in vitro experimental studies as comprehensively as possible: ('iridoid' or 'seciridoid' or 'depression'). This review extracted the experimental data on the therapeutic potential and molecular mechanism of plant-derived iridoids for depression.

RESULTS

Plant iridoids (i.e., catalpol, geniposide, loganin), and secoiridoids (i.e., morroniside, gentiopicroside, oleuropein, swertiamarin), all showed significant improvement effects on depression.

DISCUSSION AND CONCLUSIONS

Iridoids exert antidepressant effects by elevating monoamine neurotransmitters, reducing pro-inflammatory factors, inhibiting hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, increasing brain-derived neurotrophic factor (BDNF) and its receptors, and elevating intestinal microbial abundance. Further detailed studies on the pharmacokinetics, bioavailability, and key molecular targets of iridoids are also required in future research, ultimately to provide improvements to current antidepressant medications.

Network pharmacology-based prediction and verification of the active ingredients and potential targets of Huagan Decoction for reflux esophagitis

ETHNOPHARMACOLOGICAL RELEVANCE

Huagan Decoction (HGD), a famous traditional Chinese medicine (TCM) formula, has been widely used in the treatment of reflux esophagitis (RE). However, its effective compounds, potential targets and molecular mechanism remain unclear.

AIM OF THE STUDY

To investigate effective compounds, potential targets and molecular mechanism of HGD against RE by using network pharmacology combined with in vitro validation, with the aims of observing the action of HGD and exploring new therapeutic strategies for RE treatment.

MATERIALS AND METHODS

Effective compounds and potential targets of HGD, as well as related genes of RE, were collected from public databases. Pharmacological clustering and Gene Ontology (GO) enrichment analysis were applied to find targets that involving in the anti-inflammatory module. The pathways were drawn using Cytoscape 3.8.0. Important ingredients, potential targets, and signaling pathways were determined through the construction of protein-protein interaction (PPI), GO and Kyoto Encyclopedia of Genes and Genomes (KEGG). Subsequently, cell experiments were carried out.

RESULTS

A total of 54 active ingredients and 240 RE-related gene targets of HGD were identified. The active compound-target network was visualized and pharmacological clustering further sorted 53 proteins that involve in the regulation of inflammatory responses. GO analysis confirmed the classification was statistically significant. Analysis of compound-target network revealed that quercetin and geniposide may be key ingredients for the anti-inflammatory effect of HGD against RE. The potential targets regulated by HGD are IL-6, IL-1β, PTGS2, AKT1, TNF-α, MAPK1, IL-8, IL-10, CCL2 and MAPK3. In vitro experiment showed that quercetin and geniposide could inhibit the inflammatory response of HET-1A cells through p38MAPK/NF-κB signaling pathway, which was consistent with the prediction by the network pharmacology approach.

CONCLUSIONS

Geniposide and quercetin could be effective therapeutic ingredients for the HGD against RE. They play anti-inflammatory effects via down-regulating the pro-inflammatory cytokines and the conduction of p38MAPK/NF-κB signal. This research provides a comprehensive study on the active components, potential targets, and molecular mechanisms of HGD against RE. Moreover, the study supplies a feasible approach to reveal the mechanisms of TCM formula.

Perspectives of herbs and their natural compounds, and herb formulas on treating diverse diseases through regulating complicated JAK/STAT signaling

JAK/STAT signaling pathways are closely associated with multiple biological processes involved in cell proliferation, apoptosis, inflammation, differentiation, immune response, and epigenetics. Abnormal activation of the STAT pathway can contribute to disease progressions under various conditions. Moreover, tofacitinib and baricitinib as the JAK/STAT inhibitors have been recently approved by the FDA for rheumatology disease treatment. Therefore, influences on the STAT signaling pathway have potential and perspective approaches for diverse diseases. Chinese herbs in traditional Chinese medicine (TCM), which are widespread throughout China, are the gold resources of China and have been extensively used for treating multiple diseases for thousands of years. However, Chinese herbs and herb formulas are characterized by complicated components, resulting in various targets and pathways in treating diseases, which limits their approval and applications. With the development of chemistry and pharmacology, active ingredients of TCM and herbs and underlying mechanisms have been further identified and confirmed by pharmacists and chemists, which improved, to some extent, awkward limitations, approval, and applications regarding TCM and herbs. In this review, we summarized various herbs, herb formulas, natural compounds, and phytochemicals isolated from herbs that have the potential for regulating multiple biological processes via modulation of the JAK/STAT signaling pathway based on the published work. Our study will provide support for revealing TCM, their active compounds that treat diseases, and the underlying mechanism, further improving the rapid spread of TCM to the world.

PLCγ2 impacts microglia-related effectors revealing variants and pathways important in Alzheimer’s disease

Alzheimer’s disease (AD) is an irreversible neurodegenerative disease mainly characterized by memory loss and cognitive decline. The etiology of AD is complex and remains incompletely understood. In recent years, genome-wide association studies (GWAS) have increasingly highlighted the central role of microglia in AD pathology. As a trans-membrane receptor specifically present on the microglia in the central nervous system, phosphatidylinositol-specific phospholipase C gamma 2 (PLCγ2) plays an important role in neuroinflammation. GWAS data and corresponding pathological research have explored the effects of PLCG2 variants on amyloid burden and tau pathologies that underline AD. The link between PLCγ2 and other AD-related effectors in human and mouse microglia has also been established, placing PLCγ2 downstream of the triggering receptor expressed on myeloid cells 2 (TREM2), toll-like receptor 4 (TLR4), Bruton’s tyrosine kinase (BTK), and colony-stimulating factor 1 receptor (CSF1R). Because the research on PLCγ2’s role in AD is still in its early stages, few articles have been published, therefore in this paper, we integrate the relevant research published to date, review the structural features, expression patterns, and related pathways of PLCγ2, and summarize the recent studies on important PLCG2 variants related to AD. Furthermore, the possibility and challenge of using PLCγ2 to develop therapeutic drugs for AD are also discussed.

Inhibition of Dyrk1A Attenuates LPS-Induced Neuroinflammation via the TLR4/NF-κB P65 Signaling Pathway

Dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A) is a highly conserved protein kinase, playing a key role in the regulation of physiological brain functions and pathological processes. In Alzheimer's disease (AD), Dyrk1A promotes hyperphosphorylation of tau protein and abnormal aggregation of amyloid-β protein (Aβ). This study investigated the role of Dyrk1A in regulating neuroinflammation, another critical factor that contributes to AD. In the present study, we used an immortalized murine BV2 microglia cell line induced by lipopolysaccharide (LPS) to study neuroinflammation. The expression and activity of Dyrk1A kinase were both increased by inflammation. Dyrk1A inhibition using harmine or siRNA silencing significantly reduced the production of proinflammatory factors in LPS-stimulated BV2 cells. Reactive oxygen species (ROS), tumor necrosis factor-α (TNF-α), and nitric oxide (NO), as well as the expression of the inflammatory proteins, cyclooxygenase 2 (COX2), and inducible nitric synthase (iNOS), were attenuated. In vivo, in ICR mice injected with LPS into the left lateral cerebral ventricle, harmine (20 mg/kg) administration decreased the expression of inflammatory proteins in the cortex and hippocampus of mice brain. In addition, immunohistochemical detection of ionized calcium-binding adapter molecule 1 (Iba1) and Nissl staining showed that harmine significantly attenuated microglia activation and neuronal damage in the CA1 region of hippocampus. Further mechanistic studies indicated that Dyrk1A suppression may be related to inhibition of the TLR4/NF-κB signaling pathway in LPS-induced neuroinflammation. Taken together, our studies suggest that Dyrk1A may be a novel target for the treatment of neurodegenerative diseases with an inflammatory component.

The protective effect of Palmatine on depressive like behavior by modulating microglia polarization in LPS-induced mice

The purpose of the present study was to evaluate the protective effect of Palmatine on LPS-induced depressive like behavior and explore its potential mechanism. The mice were intragastrically treated with Fluoxetine or Palmatine once daily for 1 week. After the last drug administration, the mice were intraperitoneally challenged with LPS and suffered for Sucrose preference test, Tail suspension test, Forced swimming test and Open field test. The pro-inflammatory biomarkers were measured by ELISA, qPCR, WB and immunofluorescence. As a result, the administration of Palmatine effectively lessened depressive-like behavior. Palmatine could decrease the levels of pro-inflammatory cytokines TNF-α, IL-6, the expressions of CD68, iNOS mRNA, as well as increase the levels of anti-inflammatory cytokines IL-4, IL-10, the expressions of CD206, Arg1 mRNA, Ym1 mRNA both in LPS-induced mice and in LPS-induced BV2 cells. The beneficial effect of Palmatine might be attributed to the suppression of M1 microglia polarization and the promotion of M2 microglia polarization via PDE4B/KLF4 signaling. The similar results were observed in CUMS-induced depressive mice. The transfection with PDE4B SiRNA or KLF4 SiRNA indicated that PDE4B and KLF4 were both involved in the Palmatine-mediated microglia polarization. Molecular docking indicated that Palmatine could interact with PDE4B. In conclusion, this research demonstrated that Palmatine attenuated depressive like behavior by modulating microglia polarization via PDE4B/KLF4 signaling.

Shanzhiside methylester protects against depression by inhibiting inflammation via the miRNA-155-5p/SOCS1 axis

Inflammation is a key player in the regulation of depression. Shanzhiside methylester (SM) is an iridoid glycoside with strong anti-inflammatory properties. However, the antidepressant effect of SM remains unknown. The present study aimed to investigate whether SM protects against depression by targeting inflammation. A chronic unpredictable mild stress (CUMS)-induced mouse model of depression was established to assess the antidepressant effect of SM in vivo. In addition, an LPS plus ATP-induced cellular model of inflammation was used to explore the related inflammatory mechanism. We found that both SM and miRNA-155-5p sponge markedly remedied CUMS-induced depression-like behaviors in the sucrose preference test (SPT), tail suspension test (TST), and forced swim test (FST), accompanied by decreased Iba1 expression and the production of TNF-α, IL-1β, and IL-6. Moreover, SM and miRNA-155-5p sponge upregulated the protein levels of SOCS1 and downregulated the protein expression of p-JAK2 and p-STAT3 in the hippocampus of CUMS-exposed mice. miRNA-155-5p expression was also decreased following SM and miRNA-155-5p sponge administration. Furthermore, SM repressed LPS- and ATP-induced inflammatory responses in BV2 cells by regulating the SOCS1/JAK2/STAT3 signaling pathway, which was similar to the anti-inflammatory effects induced by the miRNA-155-5p sponge. Collectively, these findings suggested that SM exerted antidepressant actions by targeting the miRNA-155-5p/SOCS1 axis.

Microglia in depression: an overview of microglia in the pathogenesis and treatment of depression

Major depressive disorder is a highly debilitating psychiatric disorder involving the dysfunction of different cell types in the brain. Microglia are the predominant resident immune cells in the brain and exhibit a critical role in depression. Recent studies have suggested that depression can be regarded as a microglial disease. Microglia regulate inflammation, synaptic plasticity, and the formation of neural networks, all of which affect depression. In this review, we highlighted the role of microglia in the pathology of depression. First, we described microglial activation in animal models and clinically depressed patients. Second, we emphasized the possible mechanisms by which microglia recognize depression-associated stress and regulate conditions. Third, we described how antidepressants (clinical medicines and natural products) affect microglial activation. Thus, this review aimed to objectively analyze the role of microglia in depression and focus on potential antidepressants. These data suggested that regulation of microglial actions might be a novel therapeutic strategy to counteract the adverse effects of devastating mental disorders.

Photoresponsive Vaccine-Like CAR-M System with High-Efficiency Central Immune Regulation for Inflammation-Related Depression

Increasing evidence suggests that activation of microglia-induced neuroinflammation plays a crucial role in the pathophysiology of depression. Consequently, targeting the central nervous system to reduce neuroinflammation holds great promise for the treatment of depression. However, few drugs can enter the brain via a circulatory route through the blood-brain barrier (BBB) to reach the central nervous system efficiently, which limits the pharmacological treatment for neuropsychiatric diseases. Herein, a light-responsive system named UZPM, consisting of blue-emitting NaYF₄ :Yb, Tm@zeolitic-imidazolate framework (UCNP@ZIF-8), photoacid (PA), and melatonin (MT) is developed to address the above issues. Meanwhile, UZPM is introduced into macrophages by functional liposomes fusion and modified with hydroxylamine groups on the cell surface. Aldehyde-modified cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) is used as a chimeric antigen receptor (CAR) targeting group to modify the surface of macrophages by aldehyde/hydroxylamine condensation to precisely target central M1-type microglia (CAR-M-UZPM). Both in vitro and in vivo experiments demonstrate that the CAR-M-UZPM drug delivery system can efficiently penetrate the BBB, targeting centrally activated microglia, and thus, inhibiting the M1-type polarization of microglia, producing continuous vaccine-like anti-inflammatory effects that prevent the occurrence and development of inflammation-related depression.

Magnolol attenuates depressive-like behaviors by polarizing microglia towards the M2 phenotype through the regulation of Nrf2/HO-1/NLRP3 signaling pathway

PURPOSE

Magnolol (MA) exhibits anti-depressant effect by inhibiting inflammation. However, its effect on microglia polarization remains not fully understood. Herein, our study was performed to evaluate the effect of MA on microglia polarization in chronic unpredictable mild stress (CUMS)-induced depression and explore its potential mechanism.

STUDY DESIGN

The CUMS procedure was conducted, and the mice were intragastrically treated with MA. BV2 cells were pretreated with MA prior to LPS/ATP challenge.

METHODS

The levels of TNF-α, IL-1β, IL-6 and IL-4, IL-10 in brain and BV2 cells were examined by ELISA. The mRNA expressions of Arg1, Ym1, Fizz1 and Klf4 in brains were measured. ROS content was determined using flow cytometry. Immunofluorescence was employed to evaluate Iba-1 level, Nrf2 nuclear translocation, Iba-1⁺CD16/32⁺ and Iba-1⁺CD206⁺ cell population. The protein expressions of Nrf2, HO-1, NLRP3, caspase-1 p20 and IL-1β in brains and BV2 cells were investigated by western blot. Nrf2 siRNA was induced in experiments to explore the role of Nrf2 in MA-mediated microglia polarization. The ubiquitination of Nrf2 was visualized by Co-IP.

RESULTS

The treatment with MA notably relieved depressive like behaviors, suppressed pro-inflammatory cytokines, promoted anti-inflammatory cytokines and the transcription of M2 phenotype microglia-specific indicators. MA upregulated the expression of Nrf2, HO-1, downregulated the expression of NLRP3, caspase-1 p20, IL-1β both in vivo and in vitro. MA also reduced ROS concentration, promoted Nrf2 nucleus translocation and prevented Nrf2 ubiquitination. Nrf2 Knockdown by siRNA abolished the MA-mediated microglia polarization.

CONCLUSION

The present research demonstrated that MA attenuated CUMS-stimulated depression by inhibiting M1 polarization and inducing M2 polarization via Nrf2/HO-1/NLRP3 signaling.

Baicalin ameliorates chronic unpredictable mild stress-induced depression through the BDNF/ERK/CREB signaling pathway

Brain-derived neurotrophic factor (BDNF) can activate the extracellular regulated protein kinase (ERK)/cAMP response element binding protein (CREB) cascade revealing an important role in antidepressant effects. Here, we studied the neuroprotective effect of baicalin (BA) in mice with chronic unpredictable mild stress (CUMS)-induced via a BDNF/ERK/CREB signaling pathway. Depression was induced via six weeks of CUMS in male ICR mice, and drug therapy was given simultaneously for the last three weeks. Cognitive dysfunctions were then evaluated via sucrose preference test (SPT), open field test (OFT), Morris water maze test (MWM), tail suspension test (TST), and novelty suppressed feeding test (NSF). Western blot and real-time PCR were then used to detect the relative expression of ERK, CREB, p-ERK, and p-CREB. Integrated optical density (IOD) tests of p-ERK and p-CREB were then evaluated via immunofluorescence. The behavior results showed that the cognitive dysfunctions increased in the CUMS group versus the control (CON) group (p < 0.01). There were decreases in fluoxetine (FLU) and BA groups (p < 0.05, p < 0.01). The protein ratios of p-ERK/ERK, p-CREB/CREB and ERK mRNA, and CREB mRNA expression decreased in the CUMS group (p < 0.01) and markedly increased in the FLU and BA groups (p < 0.05, p < 0.01). The IOD value of the p-ERK and p-CREB in the CUMS group was decreased versus the CON group (p < 0.01), and these changes were improved via BA and FLU treatment (p < 0.05, p < 0.01). This study indicated that BA can improve cognitive functions and has antidepressant effects in mice, which may be associated with activation of the BDNF/ERK/CREB signaling pathway in the hippocampus.