FGF-2 signaling activation in the hippocampus contributes to the behavioral and cellular responses to puerarin

Alleviating effect of vagus nerve cutting in Salmonella-induced gut infections and anxiety-like behavior via enhancing microbiota-derived GABA

The vagus nerve, a pivotal link within the gut-brain axis, plays a critical role in maintaining homeostasis and mediating communication between the gastrointestinal tract and the brain. It has been reported that gastrointestinal infection by Salmonella typhimurium (S. typhimurium) triggers gut inflammation and manifests as anxiety-like behaviors, yet the mechanistic involvement of the vagus nerve remains to be elucidated. In this study, we demonstrated that unilateral cervical vagotomy markedly attenuated anxiety-like behaviors induced by S. typhimurium SL1344 infection in C57BL/6 mice, as evidenced by the open field test and marble burying experiment. Furthermore, vagotomy significantly diminished neuronal activation within the nucleus of the solitary tract and amygdala, alongside mitigating aberrant glial cell activation in the hippocampus and amygdala. Additionally, vagotomy notably decreases serum endotoxin levels, counters the increase in splenic Salmonella concentration, and modulates the expression of inflammatory cytokines-including IL-6, IL-1β, and TNF-α-in both the gastrointestinal tract and brain, with a concurrent reduction in IL-22 and CXCL1 expression. This intervention also fostered the enrichment of beneficial gut microbiota, including Alistipes and Lactobacillus species, and augmented the production of gamma-aminobutyric acid (GABA) in the gut. Administration of GABA replicated the vagotomy's beneficial effects on reducing gut inflammation and anxiety-like behavior in infected mice. However, blockade of GABA receptors with picrotoxin abrogated the vagotomy's protective effects against gut inflammation, without influencing its impact on anxiety-like behaviors. Collectively, these findings suggest that vagotomy exerts a protective effect against infection by promoting GABA synthesis in the colon and alleviating anxiety-like behavior. This study underscores the critical role of the vagus nerve in relaying signals of gut infection to the brain and posits that targeting the gut-brain axis may offer a novel and efficacious approach to preventing gastrointestinal infections and associated behavioral abnormalities.

Optimization of the Zhou Tian Formula extraction technology based on AHP-CRITIC method and analysis of transfer efficiency of key components based on HPLC fingerprinting

INTRODUCTION

Zhou Tian Formula (ZTF) is an antidepressant traditional Chinese medicine utilized widely in clinical settings for the treatment of patients with depression. However, shortcomings persist in its extraction technology and quality control.

OBJECTIVE

This study aimed to propose a methodology for ZTF extraction technology based on the analytic hierarchy process (AHP)-criteria importance through intercriteria correlation (CRITIC) method and to establish a quality control framework for the efficient transfer of index components.

METHOD

Firstly, we analyzed the chemical components of ZTF and determined the optimal extraction technology. Secondly, we calculated the transfer efficiency of the index components during the conversion of water decoction to extract powder and subsequently to granules. Thirdly, we established HPLC fingerprints for 15 batches of ZTF water decoction, extract powder, and granules. We employed SIMCA software to analyze the chemicals responsible for variations in quality among different batches of ZTF granules.

RESULTS

We determined the optimal extraction process. The average transfer efficiency of ferulic acid, puerarin, mirificin, isoferulic acid, and calycosin during the conversion of water decoction to extract powder and subsequently to granules exceeded 41%. The HPLC fingerprints of ZTF exhibited a similarity exceeding 0.890. Variable importance in projection values indicated that calycosin, ferulic acid, and puerarin were the primary contributors to quality variations.

CONCLUSIONS

The AHP-CRITIC method, coupled with an orthogonal array design, could be used for exploring extraction technology. In addition, the rules governing the transfer of index components from water decoction to extract powder, and subsequently to granules, could be applied for the evaluation and quality assessment of ZTF.

Investigating the Potential Therapeutic Mechanisms of Puerarin in Neurological Diseases

Plants and their derived phytochemicals have a long history of treating a wide range of illnesses for several decades. They are believed to be the origin of a diverse array of medicinal compounds. One of the compounds found in kudzu root is puerarin, a isoflavone glycoside commonly used as an alternative medicine to treat various diseases. From a biological perspective, puerarin can be described as a white needle crystal with the chemical name of 7-hydroxy-3-(4-hydroxyphenyl)-1-benzopyran-4-one-8-D-glucopyranoside. Besides, puerarin is sparingly soluble in water and produces no color or light yellow solution. Multiple experimental and clinical studies have confirmed the significant therapeutic effects of puerarin. These effects span a wide range of pharmacological effects, including neuroprotection, hepatoprotection, cardioprotection, immunomodulation, anticancer properties, anti-diabetic properties, anti-osteoporosis properties, and more. Puerarin achieves these effects by interacting with various cellular and molecular pathways, such as MAPK, AMPK, NF-κB, mTOR, β-catenin, and PKB/Akt, as well as different receptors, enzymes, and growth factors. The current review highlights the molecular mechanism of puerarin as a neuroprotective agent in the treatment of various neurodegenerative and neurological diseases. Extensive cellular, animal, and clinical research has provided valuable insights into its effectiveness in conditions such as Alzheimer's disease, Parkinson's disease, epilepsy, cerebral stroke, depression, and more.

Puerarin prevents sepsis-associated encephalopathy by regulating the AKT1 pathway in microglia

BACKGROUND

Previous studies have reported that puerarin possesses cardioprotective, vasodilatory, anti-inflammatory, anti-apoptotic, and hypoglycemic properties. However, the impact of puerarin on sepsis-associated encephalopathy (SAE) remains unexplored. In this study, we explored whether puerarin can modulate microglia-mediated neuroinflammation for the treatment of SAE and delved into the underlying mechanisms.

METHODS

We established a murine model of SAE through intraperitoneal injection of lipopolysaccharide (LPS). The puerarin treatment group received pretreatment with puerarin. For in vitro experiments, BV2 cells were pre-incubated with puerarin for 2 h before LPS exposure. We employed network pharmacology, the Morris Water Maze (MWM) test, Novel Object Recognition (NOR) test, immunofluorescence staining, enzyme-linked immunosorbent assay (ELISA), Western blotting, and quantitative real-time PCR (qRT-PCR) to elucidate the molecular mechanism of underlying puerarin's effects in SAE treatment.

RESULTS

Our findings demonstrate that puerarin significantly reduced the production of inflammatory cytokines (TNF-α and IL-6) in the peripheral blood of LPS-treated mice. Moreover, puerarin treatment markedly ameliorated sepsis-associated cognitive impairment. Puerarin also exhibited inhibitory effects on the release of TNF-α and IL-6 from microglia, thereby preventing hippocampal neuronal cell death. Network pharmacology analysis identified AKT1 as a potential therapeutic target for puerarin in SAE treatment. Subsequently, we validated these results in both in vitro and in vitro experiments. Our study conclusively demonstrated that puerarin reduced LPS-induced phosphorylation of AKT1, with the AKT activator SC79 reversing puerarin's anti-inflammatory effects through the activation of the AKT1 signaling pathway.

CONCLUSION

Puerarin exerts an anti-neuroinflammatory effect against SAE by modulating the AKT1 pathway in microglia.

Puerarin alleviates depressive-like behaviors in high-fat diet-induced diabetic mice via modulating hippocampal GLP-1R/BDNF/TrkB signaling

OBJECTIVE

Depression is one of the most common complications in patients with diabetes. Our previous study demonstrated puerarin, a dietary isoflavone, improved glucose homeostasis and β-cell regeneration in high-fat diet (HFD)-induced diabetic mice. Here, we aim to evaluate the potential effect of puerarin on diabetes-induced depression.

METHODS

The co-occurrence of diabetes and depression with related biochemical alterations were confirmed in HFD mice and db/db mice, respectively using behavioral analysis, ELISA and western blotting assay. Furthermore, impacts of puerarin on depression-related symptoms and pathological changes were investigated in HFD mice.

RESULTS

The results showed that puerarin effectively alleviated the depression-like behaviors of HFD mice, down-regulated serum levels of corticosterone and IL-1β, while up-regulated the content of 5-hydroxytryptamine. Simultaneously, puerarin increased the number of hippocampal neurons in HFD mice, and suppressed the apoptosis of neurons to protect the hippocampal neuroplasticity. GLP-1R expression in hippocampus of HFD mice was enhanced by puerarin, which subsequently activated AMPK, CREB and BDNF/TrkB signaling to improve neuroplasticity. Importantly, our data indicated that puerarin had an advantage over fluoxetine or metformin in treating diabetes-induced depression.

CONCLUSION

Taken together, puerarin exerts anti-depressant-like effects on HFD diabetic mice, specifically by improving hippocampal neuroplasticity via GLP-1R/BDNF/TrkB signaling. Puerarin as a dietary supplement might be a potential candidate in intervention of diabetes with comorbid depression.

Puerarin: a potential natural neuroprotective agent for neurological disorders

Puerarin is an isoflavone compound derived from Pueraria lobata in traditional Chinese medicine. Accumulating evidence has indicated that puerarin demonstrates multiple pharmacological effects and exhibits treatment potential for various neurological disorders. Based on the latest research progress on puerarin as a neuroprotective agent, its pharmacological activity, molecular mechanism, and therapeutic application were systematically reviewed with emphasis on pre-clinical studies. The related information was extracted and compiled from major scientific databases, including PubMed, ScienceDirect, SpringerLink, and Chinese National Knowledge Infrastructure, using 'Puerarin', 'Neuroprotection', 'Apoptosis', 'Autophagy', 'Antioxidant', 'Mitochondria', 'Anti-inflammation' as keywords. This review complied with The Preferred Reporting Items for Systematic Reviews criteria. Forty-three articles met established inclusion and exclusion criteria. Puerarin has shown neuroprotective effects against a variety of neurological disorders, including ischemic cerebrovascular disease, subarachnoid hemorrhage, epilepsy, cognitive disorders, traumatic brain injury, Parkinson's disease, Alzheimer's disease, anxiety, depression, diabetic neuropathy, and neuroblastoma/glioblastoma. Puerarin demonstrates anti-apoptosis, proinflammatory mediator inhibitory, autophagy regulatory, anti-oxidative stress, mitochondria protection, Ca²⁺ influx inhibitory, and anti-neurodegenerative activities. Puerarin exerts noticeable neuroprotective effects on various models of neurological disorders in vivo (animal). This review will contribute to the development of puerarin as a novel clinical drug candidate for the treatment of neurological disorders. However, well-designed, high-quality, large-scale, multicenter randomized clinical studies are needed to determine the safety and clinical utility of puerarin in patients with neurological disorders.

Therapeutic potential of puerarin against cerebral diseases: From bench to bedside

The incidence of cerebral diseases is rapidly increasing worldwide, and they have become an important challenge for modern medicine. Most of the available chemical drugs used in the treatment of cerebral diseases are highly toxic and single-targeted. Therefore, novel drugs from natural resources have attracted much attention for their potential to manage cerebral diseases. Puerarin is a natural isoflavone isolated from the roots of Pueraria species such as P. lobata (Willd) Ohwi, P. thomsonii, and P. mirifica. Several authors have reported the beneficial effects of puerarin in cerebral ischemic disease, intracerebral hemorrhage, vascular dementia, Alzheimer's disease, Parkinson's disease, depression, anxiety, and traumatic brain injury. This review summarizes the brain pharmacokinetics, brain drug delivery system, clinical use (in cerebral diseases), toxicity, and the adverse clinical reactions of puerarin. We have systematically presented the pharmacological actions and the molecular mechanisms of puerarin in various cerebral diseases to provide a direction for future research on the therapeutic use of puerarin in cerebral diseases.

Inhibition of Microglial NLRP3 with MCC950 Attenuates Microglial Morphology and NLRP3/Caspase-1/IL-1β Signaling In Stress-induced Mice

Major depressive disorder is characterized by the deficiencies of monoamine neurotransmitters, neurotrophic factors and persistent neuroinflammation. Microglial activation has been associated with neuroinflammation-related mental diseases, accompanied by NLR family pyrin domain containing 3 (NLRP3) inflammasome. Here, we investigated the effect of NLRP3 inhibition by its small molecular inhibitor MCC950 on inflammatory activity and depressive-like mice induced by chronic unpredictable mild stress (CUMS), followed by the behavioral tests including sucrose preference test and forced swimming test. NLRP3/caspase-1/IL-1β signaling and microglial morphology in the prefrontal cortex were measured. The results showed that CUMS caused a decrease in sucrose preference and an increase in immobility time, which were reversed by NLRP3 inhibitor MCC950. In addition, NLRP3 inhibition decreased the number of microglia and changed the activated state of microglia to a resting state by morphology 3D reconstruction. Moreover, NLRP3 inhibition inactivated NLRP3/caspase-1/IL-1β signaling in the prefrontal cortex. The results from immunofluorescence demonstrated that NLRP3 and IL-1β expression was decreased in microglia in response to MCC950 treatment. Accordingly, proinflammatory cytokines were also decreased by NLRP3 inhibition. In conclusion, this study demonstrates that microglial NLRP3 inhibition prevents stress-induced neuroinflammation in the prefrontal cortex and suggests that microglial NLRP3 could be one of the potential therapeutic targets for depression treatment.

Pharmacological Activity, Pharmacokinetics, and Clinical Research Progress of Puerarin

As a kind of medicine and food homologous plant, kudzu root (Pueraria lobata (Willd.) Ohwi) is called an "official medicine" in Chinese folk medicine. Puerarin is the main active component extracted from kudzu root, and its structural formula is 8-β-D-grapes pyranose-4, 7-dihydroxy isoflavone, with a white needle crystal; it is slightly soluble in water, and its aqueous solution is colorless or light yellow. Puerarin is a natural antioxidant with high health value and has a series of biological activities such as antioxidation, anti-inflammation, anti-tumor effects, immunity improvement, and cardio-cerebrovascular and nerve cell protection. In particular, for the past few years, it has also been extensively used in clinical study. This review focuses on the antioxidant activity of puerarin, the therapy of diverse types of inflammatory diseases, various new drug delivery systems of puerarin, the "structure-activity relationship" of puerarin and its derivatives, and pharmacokinetic and clinical studies, which can provide a new perspective for the puerarin-related drug research and development, clinical application, and further development and utilization.

Sex differences in stress-induced alcohol intake: a review of preclinical studies focused on amygdala and inflammatory pathways

Clinical studies suggest that women are more likely than men to relapse to alcohol drinking in response to stress; however, the mechanisms underlying this sex difference are not well understood. A number of preclinical behavioral models have been used to study stress-induced alcohol intake. Here, we review paradigms used to study effects of stress on alcohol intake in rodents, focusing on findings relevant to sex differences. To date, studies of sex differences in stress-induced alcohol drinking have been somewhat limited; however, there is evidence that amygdala-centered circuits contribute to effects of stress on alcohol seeking. In addition, we present an overview of inflammatory pathways leading to microglial activation that may contribute to alcohol-dependent behaviors. We propose that sex differences in neuronal function and inflammatory signaling in circuits centered on the amygdala are involved in sex-dependent effects on stress-induced alcohol seeking and suggest that this is an important area for future studies.

IL-1R/C3aR signaling regulates synaptic pruning in the prefrontal cortex of depression

Background

Major depressive disorder is characterized by not only monoamine neurotransmitters deficiencies but also persistent neuroinflammation. The complement system is an attractive therapeutic target for various inflammation-related diseases due to its early activation in inflammatory processes.

Results

In the present study, the dynamic alteration of complement C3 and its receptor C3aR during the occurrence of depression and the mechanism of astrocyte-microglia IL-1R/C3/C3aR on synaptic pruning were investigated. The proteomic analysis firstly showed that chronic stress caused an elevation of C3. GO analysis indicated that complement system-mediated synaptic pruning signaling was involved in depression. The dynamic observation indicated that C3/C3aR was activated in the early onset and throughout the course of depression induced by lipopolysaccharide (LPS) and chronic stress. In contrast, C3aR blockade inhibited the hyperactivation of microglial APT2/DHHC7 palmitoylation cycle, which mediated the translocation of STAT3 and the expression of proinflammatory cytokines. Meanwhile, C3aR blockade also attenuated the synaptic pruning and enhanced the synaptogenesis in the prefrontal cortex of mice. Moreover, the blockade of IL-1R/NF-κB signaling pathway reduced the release of C3 from astrocyte.

Conclusions

The current study demonstrates that astrocyte-microglia IL-1R/C3/C3aR activation causes the abnormal synaptic pruning in depression, and suggests that the activation of complement C3/C3aR may be particularly helpful in predicting the onset stage of depression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00832-4.

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.

Scream Sound-induced Chronic Psychological Stress Results in Diminished Ovarian Reserve in Adult Female Rat

It is well established that chronic psychological stress (PS) induces female reproductive dysfunction. However, the studies on the consequences of chronic PS exposure precisely targeting ovarian reserve are lacking. In the present study, we employed a chronic scream sound-induced PS model to investigate the potential effect of pure psychosocial stressors on ovary reserve. Female rats were subjected to scream sound stress, white noise, or background for 3 weeks. Animals were euthanized by cervical dislocation after stress for collection of blood or ovaries. Sex hormones were analyzed by enzyme-linked immunosorbent assay. The follicle number was examined by histopathology. Granulosa cell apoptosis of the ovaries was examined by in situ cell death detection kit. Finally, rats were mated with proven fertile male rats to study fertility parameters. Female rats exposed to scream sound were presented with reduced weight gain and sucrose preference, while immobility time in forced swim test and serum corticosterone concentration were significantly increased. Scream sound stress sequentially decreased plasma anti-Müllerian hormone and estradiol concentration, induced primordial and preantral follicles loss, augmented granulosa cell apoptosis in ovarian growing follicles, and eventually decreased litter sizes. Based on these results, we suggest that chronic PS induced loss of ovarian reserve by accelerated primordial follicle activation and destruction of growing follicles, which results in follicle depletion and decreased fertility.

Evidence and Characteristics of Traditional Chinese Medicine for Coronary Heart Disease Patients With Anxiety or Depression: A Meta-Analysis and Systematic Review

Aims: The objective of this study was to assess the efficacy and potential mechanisms of Chinese herbal medicine (CHM) for treating coronary heart disease (CHD) patients with anxiety or depression.

Methods: A systematic literature search was performed. Screening studies, extracting data, and assessing article quality were carried out independently by two researchers. The active ingredients of CHM for the treatment of CHD with anxiety or depression were analyzed by the network pharmacology, and the main potential mechanisms were summarized by the database of Web of Science.

Results: A total of 32 studies were included. The results showed that compared with the blank control groups, CHM was more beneficial in treating anxiety or depression in patients with CHD [anxiety: OR = 3.22, 95% CI (1.94, 5.35), p < 0.00001, I2 = 0%; depression: OR = 3.27, 95% CI (1.67, 6.40), p = 0.0005, I2 = 0%], and the efficacy of CHM was not inferior to that of Western medicine (WM) [anxiety: OR = 1.58, 95%CI (0.39, 6.35), p = 0.52, I2 = 67%; depression: OR = 1.97, 95%CI (0.73, 5.28), p = 0.18, I2 = 33%,]. Additionally, CHM also showed a significant advantage in improving angina stability (AS) in CHD patients with anxiety or depression compared with blank groups [anxiety: SMD = 0.55, 95%CI (0.32, 0.79), p < 0.00001, I2 = 0%; depression: p = 0.004] and WM groups [anxiety: SMD = 1.14, 95%CI (0.80, 1.47), p < 0.00001, I2 = 0%; depression: SMD = 12.15, 95%CI (6.07, 18.23), p < 0.0001, I2 = 0%]. Angina frequency (AF) and electrocardiogram (ECG) analysis after using CHM demonstrated similar trends. Based on the network pharmacology, quercetin, kaempferol, luteolin, beta-sitosterol, puerarin, stigmasterol, isorhamnetin, baicalein, tanshinone IIa, and nobiletin were most closely and simultaneously related to the pathological targets of CHD, anxiety, and depression. The main underlying mechanisms might involve anti-damage/apoptosis, anti-inflammation, antioxidative stress, and maintaining neurotransmitter homeostasis.

Conclusion: CHM exhibited an obvious efficacy in treating CHD patients with anxiety or depression, especially for improving the symptom of angina pectoris. The most active compounds of CHM could simultaneously act on the pathological targets of CHD, anxiety, and depression. Multiple effective components and multiple targets were the advantages of CHM compared with WM.

Puerarin action on stem cell proliferation, differentiation and apoptosis: Therapeutic implications for geriatric diseases

BACKGROUND

Aging is associated with a decline in cognitive and physical functions and various geriatric diseases, such as cardiovascular and neurodegenerative diseases. Puerarin (Pue), one of the main active flavonoids of Radix Puerariae (R. pueraria), is reportedly effective in treating geriatric diseases, including cardiovascular disease and hypertension.

PURPOSE

This review aims to summarize and discuss the profound physiological impact of Pue on various stem cell populations and provide new insights into the use of Pue for the prevention and treatment of geriatric diseases.

METHODS

The literature was retrieved from the core collection of electronic databases, such as Web of Science, Google Scholar, PubMed, and Science Direct, using the following keywords and terms: Puerarin, Stem Cell, Proliferation, Differentiation, Apoptosis, and Geriatric diseases. These keywords were used in multiple overlapping combinations.

RESULTS

Pue is effective in the treatment and management of age-related diseases, such as cardiovascular disease, diabetes, hypertension, and cerebrovascular disease. Pue exerts significant physiological effects on various stem cell populations, including their self-renewal/proliferation, differentiation and apoptosis. Most importantly, it could improve the efficiency and accuracy of stem cell therapy for treating various geriatric diseases. Further studies are essential to improve our understanding of the underlying mechanisms and elucidate their significance for future clinical applications.

CONCLUSION

The effects of Pue on various stem cell populations and their regulatory mechanisms are discussed in detail to provide new insights into the use of Pue in the prevention and treatment of geriatric diseases.

Neuroprotective Mechanisms of Puerarin in Central Nervous System Diseases: Update

Due to global population aging and modern lifestyle changes, the incidence of central nervous system (CNS) disorders, such as neurodegenerative diseases, neuropsychiatric disorders, and cerebrovascular diseases, is increasing and has become a major public health challenge. Current medications commonly used in the clinic are far from satisfactory and may cause serious side effects. Therefore, the identification of novel drugs for the effective management of CNS diseases is very urgent. Puerarin, a highly bioactive ingredient isolated from Pueraria lobata, is known to possess a broad spectrum of pharmacological properties including anti-diabetic, anti-inflammatory, anti-antioxidant, neuroprotective, and cardioprotective features. However, its clinical application is limited due to its poor water solubility. Since puerarin has demonstrated a wide range of neuroprotective functions in various CNS diseases, such as Alzheimer’s disease, Parkinson’s disease, cerebral ischemia, depression, and spinal cord injury, it has been attracting increasingly intense attention worldwide. In this review, we intend to extensively summarize the research progress on neuroprotective mechanisms of puerarin in recent years and discuss the future directions of its application in CNS disease treatment.

Chinese Pharmacopoeia Revisited: A Review of Anti-Depression Herbal Sources

Depression, which can be accompanied by many fatal diseases and a low life quality, has become the leading cause of ill health and disability worldwide. However, Chinese Pharmacopoeia, the most authoritative and evidence-based encyclopedia of Traditional Chinese Medicine (TCM), could contain leads and insights into the development of new antidepressant drugs. In this work, nine herbal medicines with ‘dispel melancholy functions’ specifically documented in Chinese Pharmacopoeia have been comprehensively reviewed with respect to clinical trials, and phytochemical and pharmacological aspects. The nine drugs are Rosae Chinensis Flos, Croci Stigma, Albiziae Cortex and Flos, Roase Rugosae Flos, Curcumae Radix, Hyperici Perforati Herba, Cyperi Rhizoma and Bupleuri Radix. The mechanisms of action of their functional antidepressant compounds, including gallic acid, hypericin, kaempferol, crocetin, crocin, quercetin, luteolin, isorhamnetin, curcumin, hyperforin, adhyperforin, catechin, rutin, puerarin, and saikosaponins A and D, have been collected and discussed. These traditional Chinese herbs and their active compounds provide a promising resource to develop effective new antidepressant drugs in future. Moreover, mechanistic investigations, safety verification and large-scale clinical trials are still expected to finally transform such TCM-based antidepressant resources to new drugs for patients suffering from depression.

Botanical Drug Puerarin Ameliorates Liposaccharide-Induced Depressive Behaviors in Mice via Inhibiting RagA/mTOR/p70S6K Pathways

BACKGROUND

The depressive symptom hallmarks the progression of the neurodegenerative diseases, especially Alzheimer's disease. Bacterial infection is related to inflammation and depression. The present project thereby examined whether botanical drug puerarin could attenuate liposaccharide- (LPS-) induced depressive behaviors in mice.

METHODS

Adult male C57BL/6N mice were sequentially treated with LPS and puerarin and evaluated for the depressive behaviors by tail suspension test and forced swim test. The brain tissues were profiled for the molecular targets of puerarin by next-generation RNA sequencing technique. Candidate targets were further verified in LPS-treated mice, neural stem cells, and highly differentiated PC12 cell line.

RESULTS

Puerarin ameliorated LPS-induced depression in the mice. RNA sequencing profiles revealed that puerarin altered the expression of 16 genes while markedly downregulated Ras-related GTP-binding protein A (RagA) in LPS-treated mice. The effect of puerarin on RagA expression was confirmed by immunostaining, Western blot, and quantitative real-time PCR (qRT-PCR). Biochemical studies showed that puerarin inhibited RagA/mTOR/p70S6K pathway, attenuated the accumulation of mTORC1 in close proximity to lysosome, and reduced the production of proinflammatory cytokines.

CONCLUSIONS

Botanical drug puerarin attenuated inflammation and depressive behaviors in LPS-challenged mice by inhibiting RagA/mTOR/p70S6K pathways. Puerarin may be a lead compound for the new antidepressant drugs.

Screening and Identification of Antidepressant Active Ingredients from Puerariae Radix Extract and Study on Its Mechanism

Objective. Depression is a common mental disease with long course and high recurrence rate. Previous studies showed that Puerariae Radix and its extracts have powerful antidepressant effects in recent years. The study proposed an integrated strategy, combining network pharmacology and molecular pharmacology experiment to investigate the mechanisms of the antidepressant active ingredients from Puerariae Radix. Methods. TCMSP database, GeneCards database, Venny 2.1, UniProt database, STRING database, Cytoscape 3.7.2, and Metascape database were used to screen the active chemical components, antidepressant-related genes, and core targets, convert the abbreviated gene names in batch, search and predict the interaction between proteins, and construct the PPI network of Puerariae Radix. KEGG pathway and GO biological process enrichment and biological annotation were used to select antidepressant core gene targets. The MTT method was used to detect the effect of puerarin on the damage of PC12 cells induced by corticosterone. The DCFH-DA probe and ROS assay kit were utilized to detect the production of ROS in PC12 cells. PI/Annexin V was used to detect the apoptotic rate of puerarin on PC12 cells. Western blotting was used to verify the regulation of puerarin on the key targets of AKT1, FOS, CASP3, STAT3, and TNF-α in PC12 cells. Results and Conclusion. Eight main active components, 64 potential antidepressant gene targets, and 15 core antidepressant gene targets were obtained. 35 signaling pathways and 52 biological processes related to antidepressant effect of Puerariae Radix were identified. Puerarin was the active ingredient derived from Puerariae Radix which exhibited the antidepression effect by improving the viability of cell, reducing cell apoptosis, regulating ROS production, increasing protein expressions of AKT1 and FOS, and reducing protein expressions of CASP3, STAT3, and TNF-α. The study revealed the pharmacodynamic material basis and possible antidepressant mechanism of Puerariae Radix and provided new theoretical basis and ideas for antidepressant research.

Paeoniflorin exerts antidepressant-like effects through enhancing neuronal FGF-2 by microglial inactivation

Ethnopharmacological relevance Paeonia lactiflora is a famous Traditional Chinese medicine widely used for immunological regulation. Paeoniflorin, the main component of Paeonia lactiflora, exerts neuroprotective and antidepressant-like effects in rodents.

AIM OF THE STUDY

Fibroblast growth factor 2 (FGF-2) is essentially required in the central nervous system as it acts as both a neurotrophic factor and an anti-inflammatory factor participating in the regulation of proliferation, differentiation and apoptosis of neurons in the brain. However, it is unclear whether paeoniflorin could exert antidepressant effects via regulating FGF-2.

MATERIALS AND METHODS

In the present study, the effects of paeoniflorin were evaluated in depressive mice induced by the endotoxin lipopolysaccharide (LPS) injection.

RESULTS

The results showed that paeoniflorin markedly increased sucrose preference and reduced immobility time in LPS mice, indicating antidepressant effects. Consistent with the results from molecular docking showing paeoniflorin antagonizes TLR4, NF-κB and NLRP3, the biochemical analysis also indicated paeoniflorin inhibited TLR4/NF-κB/NLRP3 signaling, decreased proinflammatory cytokine levels and microglial activation in the hippocampus of LPS induced mice. In addition, the levels of neuronal FGF-2 and the density of dendritic spine were improved by paeoniflorin. More importantly, the FGFR1 inhibitor SU5402 prevented the antidepressant effects of paeoniflorin and blocked the neuroinflammatory and neurogenic regulatory effects of paeoniflorin, indicating that FGF-2/FGFR1 activation was required for the effects of paeoniflorin.

CONCLUSION

Taken together, the results demonstrate that paeoniflorin exhibits neuroprotective and antidepressant effects in mice, which may be mediated by activating neuronal FGF-2/FGFR1 signaling via the inhibition of microglial activation in the hippocampus.

Do changes in microglial status underlie neurogenesis impairments and depressive-like behaviours induced by psychological stress? A systematic review in animal models

Stress may have a negative effect on mental health and is the primary environmental risk factor in the aetiology of depression. Nevertheless, the neurobiological mechanisms underlying this mood disorder remain poorly characterized. The hippocampus is a target structure of the adverse effects of stress, and hippocampal neurogenesis plays a crucial role. However, we do not know the mechanisms by which stress impacts neurogenesis. Recent studies indicate that changes in neuroinflammation, primarily via microglial cells, may play an essential role in this process. However, the relationship between stress, microglial changes, and alterations in neurogenesis and their involvement in the development of depression is poorly characterized. For this reason, this systematic review aims to synthesise and evaluate current studies that have investigated the relationship between these variables. Taken together, the revised data, although not entirely conclusive, seem to suggest that microglial changes induced by psychological stress regulate neurogenesis and in turn may be responsible for the development of depressive-like behaviours, but other factors that influence these stressful experiences should not be dismissed.

Combined Extract of Leonurus japonicus Houtt, Eclipta prostrata L., and Pueraria lobata Ohwi Improved Hot Flashes and Depression in an Ovariectomized Rat Model of Menopause

Menopause leads to ovarian hormone loss, which causes symptoms such as weight gain, hot flashes, and depression. Exploring nutraceuticals is important for treating menopausal symptoms that extensively impact women's quality of life. We hypothesized that a combination of Leonurus japonicus Houtt, Eclipta prostrata L., and Pueraria lobata Ohwi (LEPE) would alleviate menopausal symptoms in an ovariectomized menopausal rat model. Bilateral ovariectomy was performed and animals were assigned to five groups: (1) Sham, (2) Vehicle, (-) Control, (3) LEPE (100 mg/kg bw), (4) LEPE (200 mg/kg bw), and (5) Estradiol (3 μg/kg bw). LEPE was orally administered daily for 12 weeks. LEPE supplementation did not affect growth performance (body weight and feed intake) or body composition (lean mass and fat in tissue). LEPE did not cause deviations in aspartate aminotransferase, alanine aminotransferase, estradiol, and follicle-stimulating hormone levels, indicating no hepatotoxicity or endocrine disturbance. LEPE decreased type I collagen (CTX-1) but did not affect bone mineral density or osteocalcin. LEPE decreased tail temperature and increased rectal temperature, improving menopause-related vasomotor symptoms. Furthermore, LEPE ameliorated depression-related behavior, including in forced swimming and tail suspension tests. Thus, LEPE may improve menopausal symptoms by enhancing vasomotor symptoms and depression in an ovariectomized rat menopause model.

Fibroblast growth factor 2 contributes to the effect of salidroside on dendritic and synaptic plasticity after cerebral ischemia/reperfusion injury

Ischemic stroke, a serious neurological disease, is associated with cell death, axonal and dendritic plasticity, and other activities. Anti-inflammatory, anti-apoptotic, promote dendritic and synaptic plasticity are critical therapeutic targets after ischemic stroke. Fibroblast growth factor-2 (FGF2), which is involved in the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/CAMP response element (CRE)-binding protein (CREB) pathway, has been shown to facilitate dendritic and synaptic plasticity. Salidroside (Sal) has been reported to have anti-inflammatory, anti-oxidative, and anti-apoptotic effects; however, the underlying mechanisms of Sal in promoting dendritic and synaptic plasticity remain unclear. Here, the anti-inflammatory, anti-apoptotic, dendritic and synaptic plasticity effects of Sal were investigated in vitro in PC12 cells under oxygen-glucose deprivation/reoxygenation (OGD/R) conditions and in vivo in rats with middle cerebral artery occlusion/reperfusion (MCAO/R). We investigated the role of Sal in promoting dendritic and synaptic plasticity in the ischemic penumbra and whether the FGF2-mediated cAMP/PKA/CREB pathway was involved in this process. The present study demonstrated that Sal could significantly inhibit inflammation and apoptosis, and promote dendritic and synaptic plasticity. Overall, our study suggests that Sal is an effective treatment for ischemic stroke that functions via the FGF2-mediated cAMP/PKA/CREB pathway to promote dendritic and synaptic plasticity.