Antidepressant-like effects of Z-ligustilide on chronic unpredictable mild stress-induced depression in rats

Quercetin attenuates brain apoptosis in mice with chronic unpredictable mild stress-induced depression

BACKGROUND

Depression is a common psychiatric disorder with limited effective treatments. Research suggests that depression involves apoptosis mechanisms. Quercetin (QUE) has been reported to have anti-apoptotic activities. In this study, we aimed to investigate the effects and mechanisms of QUE in chronic unpredictable mild stress (CUMS)-induced depression.

METHODS

After establishing mouse models of CUMS-induced depression, the mice were randomly assigned into four groups: control, CUMS, CUMS+QUE, and CUMS+Fluoxetine (FLX). The body weight of the mice was measured during the study. Then, depression-associated behaviors were evaluated using the sucrose preference test (SPT), novelty suppressed feeding test (NSFT), forced swim test (FST) and tail suspension test (TST). Apoptosis in the hippocampus and prefrontal cortex was determined using flow cytometry. Bcl-2 and Nrf2 protein expressions in the hippocampus and prefrontal cortex were also detected. Furthermore, Western blot was used to measure the protein levels of p-ERK, ERK, p-CREB, CREB, and Nrf2 in brain tissues.

RESULTS

QUE or FLX administration increased the body weight of the CUMS mice. Behavioral tests indicated that CUMS mice developed a state of depression, but QUE or FLX treatment improved their depression-associated behaviors. Meanwhile, QUE or FLX treatment decreased apoptosis in the hippocampus and prefrontal cortex. Furthermore, the decreased Nrf2 protein expression, ERK and CREB phosphorylation in CUMS group were enhanced by QUE or FLX administration.

CONCLUSION

QUE could attenuate brain apoptosis in mice with CUMS-induced depression, and the mechanism may be related to the ERK/Nrf2 pathway, indicating that QUE could be a potential treatment for depression.

The anti-depression effect and potential mechanism of the petroleum ether fraction of CDB: Integrated network pharmacology and metabolomics

The combination of Chaidangbo (CDB) is an antidepressant traditional Chinese medicine (TCM) prescription simplified by Xiaoyaosan (a classic antidepressant TCM prescription) through dismantling research, which has the effect of dispersing stagnated liver qi and nourishing blood in TCM theory. Although the antidepressant effect of CBD has been confirmed in animal studies, the material basis and possible molecular mechanism for antidepressant activity in CBD have not been clearly elucidated. Herein, we investigated the effects and potential mechanisms of CDB antidepressant fraction (petroleum ether fraction of CDB, PEFC) on chronic unpredictable mild stress (CUMS)-induced depression-like behavior in mice using network pharmacology and metabolomics. First, a UPLC-QE/MS was employed to identify the components of PEFC. To extract active ingredients, SwissADME screening was used to the real PEFC components that were found. Potential PEFC antidepressant targets were predicted based on a network pharmacology approach, and a pathway enrichment analysis was performed for the predicted targets. Afterward, a CUMS mouse depression model was established and LC-MS-based untargeted hippocampal metabolomics was performed to identify differential metabolites, and related metabolic pathways. Finally, the protein expressions in mouse hippocampi were determined by Western blot to validate the network pharmacology and metabolomics deduction. A total of 16 active compounds were screened in SwissADME that acted on 73 core targets of depression, including STAT3, MAPKs, and NR3C1; KEGG enrichment analysis showed that PEFC modulated signaling pathways such as PI3K-Akt signaling pathway, endocrine resistance, and MAPK to exert antidepressant effects. PEFC significantly reversed abnormalities of hippocampus metabolites in CUMS mice, mainly affecting the synthesis and metabolism of glycine, serine, and threonine, impacting catecholamine transfer and cholinergic synapses and regulating the activity of the mTOR signaling pathway. Furthermore, Western blot analysis confirmed that PEFC significantly influenced the main protein levels of the PI3K/Akt/mTOR signaling pathways in the hippocampus of mice subjected to CUMS. This study integrated metabolomics, network pharmacology and biological verification to explore the potential mechanism of PEFC in treating depression, which is related to the regulation of amino acid metabolism dysfunction and the activation of PI3K/Akt/mTOR signaling pathways in the hippocampus. The comprehensive strategy also provided a reasonable way for unveiling the pharmacodynamic mechanisms of multi-components, multi-targets, and multi-pathways in TCM with antidepressant effect.

Comprehensive multicomponent characterization and quality assessment of Xiaoyao Wan by UPLC-Q-Orbitrap-MS, HS-SPME-GC-MS and HS-GC-IMS

Xiaoyao Wan (XYW) is a prescription medicine of traditional Chinese medicine (TCM) with the effects of "soothing the liver and relieving depression," and "strengthening spleen and nourishing blood". XYW has been widely concerned in the treatment of depression and has become one of the commonly used classic formulas in clinical practice. However, the pharmacodynamic substance basis and the quality control studies of XYW are hitherto quite limited. Here, we aim to fully utilize an advanced ultra - performance liquid chromatography-quadrupole - Orbitrap mass spectrometry (UPLC-Q-Orbitrap-MS), headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) technique to deep characterization of the pharmacological substance basis and quantitatively evaluate the quality of XYW. Firstly, 299 compounds were identified or tentatively characterized, including 198 non-volatile organic compounds (n-VOCs) and 101 volatile organic compounds (VOCs). Secondly, principal component analysis (PCA) and hierarchical cluster analysis (HCA) was used to analyze quality differences in XYW at different manufacturers. Thirdly, a parallel reaction monitoring (PRM) method was established and validated to quantify the fourteen major effective substances in different manufacturers of XYW, which were chosen as the benchmarked substances to evaluate the quality of XYW. In conclusion, this study shows that the strategy provides a useful method for quality control of TCM and offers a practical workflow for exploring the quality consistency of TCM.

Protective effect of Baoyuan Jieyu formula on long-term spaceflight composite stress-induced depressive-like behavior and memory deficits through regulation of Ca2+ channel currents

Long-term spaceflight composite stress (LSCS) can cause adverse effects on human systems, especially the central nervous system. This study aimed to identify the underlying mechanisms of the protective effect of Baoyuan Jieyu Formula (BYJYF) on LSCS-induced depressive-like behavior and memory deficits. In this experiment, we simulated the real space station environment for a period of 42 days. Novel object recognition test and forced swimming test were used to assess the memory abilities and depression level of rats as well as test the therapeutic effects of BYJYF treatment. Results showed LSCS could induce depressive-like behavior and damage short-term memory in the behavioral level, and BYJYF could enhance the ability to resist LSCS. Meanwhile, LSCS increased the levels of CRH, ACTH, and CORT and induced HPA axis hyperactivity, which can be relieved by BYJYF. Further, we predicted and verified the potential signaling pathways of BYJYF. Results showed BYJYF may reverse the inhibition of LSCS on Ca2+ channel currents. And we also found that BYJYF may exert its medicinal effects via four main active components including saikosaponin A. Overall, BYJYF exhibited protective effects against LSCS-induced depressive-like behavior and memory deficits, which might be ascribed to the regulation of Ca2+ channel currents and four active components. And it might become a promising candidate medicine for diseases induced by LSCS.

The regulatory effect of Angelicae Sinensis Radix on neuroendocrine-immune network and sphingolipid metabolism in CUMS-induced model of depression

ETHNOPHARMACOLOGICAL RELEVANCE

Conventional antidepressants therapy remains unsatisfactory due to the disadvantages of delayed clinical onset of action and side effects. Traditional Chinese Medicine (TCM) with good efficacy and higher safety have received much attention. Angelicae Sinensis Radix (AS), a well-known TCM, has been proved to exhibit the efficacy of antidepression recently.

AIM OF THE STUDY

The purpose of this study was to investigate the potential anti-depressant mechanisms of AS based on chronic unpredictable mild stress (CUMS) rat model.

MATERIALS AND METHODS

In this study, behavioral experiments, molecular biology techniques, and ultra performance liquid chromatography-triple-time of flight mass spectrometer (UPLC-Triple-TOF/MS) were combined to explore the potential antidepressant mechanisms of AS based on CUMS rat model.

RESULTS

The results demonstrated that AS could reduce the contents of serum hypothalamic-pituitary-adrenal (HPA) axis hormones in CUMS rats, including corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and cortisol (CORT). In addition, AS regulated the percentage of CD4+ T lymphocytes, the ratio of CD4+/CD8+, and the levels of serum cytokines such as IL-1β, IL-4, IL-6, and TNF-α in CUMS rats. Lipidomics showed that 31 lipids were related to depression and AS could regulate the lipid metabolism alteration induced by CUMS, particularly sphingolipid metabolism. Finally, the key proteins in sphingolipid metabolic pathways in hippocampus of CUMS rats could be back-regulated by AS, including serine palmitoyl transferase (SPTLC2), ceramide synthase (CerS2), sphingomyelinase (SPHK1), and neutral sphingomyelinase (nSMase).

CONCLUSION

AS could alleviate NEI network disorder and restore the levels of sphingolipid metabolites and key proteins in CUMS rats. The underlying mechanism by which AS relieved depression-like behavior in CUMS rats may be through modulation of NEI and disturbances in sphingolipid metabolism.

A narrative review of potential neural repair poststroke: Decoction of Chinese angelica and peony in regulating microglia polarization through the neurosteroid pathway

Ischemic stroke is a major global health crisis, characterized by high morbidity and mortality rates. Although there have been significant advancements in treating the acute phase of this condition, there remains a pressing need for effective treatments that can facilitate the recovery of neurological functions. Danggui-Shaoyao-San (DSS), also known as the Decoction of Chinese Angelica and Peony, is a traditional Chinese herbal formula. It has demonstrated promising results in the regulation of microglial polarization and modulation of neurosteroid receptor expression, which may make it a potent strategy for promoting the recovery of neurological functions. Microglia, which plays a crucial role in neuroplasticity and functional reconstruction poststroke, is regulated by neurosteroids. This review posits that DSS could facilitate the recovery of neuronal function poststroke by influencing microglial polarization through the neurosteroid receptor pathway. We will further discuss the potential mechanisms by which DSS could enhance neural function in stroke, including the regulation of microglial activation, neurosteroid regulation, and other potential mechanisms.

Comprehensive quality evaluation of two different geography originated Angelica sinensis Radix based on potential production area development and resource protection

Angelica sinensis Radix (ASR) is mainly produced in the southern region of Gansu, China, and is a famous edible and medicinal herb. Noticeably, Aba region in Sichuan, China has similar geographical and climatic conditions to the southern region of Gansu, China, and has the potential to further develop the ASR planting industry chain. This study was the first to use an innovative method that combines GC-MS, HPLC-DAD fingerprints, and stoichiometric analysis to compare and explore the feasibility of using the Aba region as a source of high-quality ASR supplements. GC-MS analysis showed that the composition of ASR essential oil(AEO) in these two regions was highly similar (>99%). The HPLC data showed that the main sources of differences in ASR components between the two regions were coniferyl ferulate, E-ligustilide, Z-ligustilide, and Butylidenephthalide, which have great potential in anti-depression, regulating gut microbiota, and other aspects. The ASR in Aba region was rich in these components, and its biological activity might be higher to some extent than that in southern Gansu. This study confirmed the potential of the Aba region in Sichuan to become a high-quality production area for ASR, which was conducive to the expansion of ASR resources and the development of related industrial chains.

Screening the effective components of Suanzaoren decoction on the treatment of chronic restraint stress induced anxiety-like mice by integrated chinmedomics and network pharmacology

BACKGROUND

Suanzaoren decoction (SZRD) is a classical traditional Chinese prescription. It is widely used to treat mental disorders, including insomnia, anxiety, and depression, in China and other Asian countries. However, the effective components and mechanisms underlying SZRD remained unclear.

PURPOSE

We aimed to develop a new strategy to discover the effects and potential mechanisms of SZRD against anxiety and to further reveal the effective components of SZRD in treating anxiety.

STUDY DESIGN AND METHODS

First, the chronic restraint stress (CRS)-induced mouse model of anxiety was orally administered SZRD, and behavioral indicators and biochemical parameters were applied to assess efficacy. A chinmedomics strategy based on UHPLC-Q-TOF-MS technology and network pharmacology were then used to screen and explore potentially effective components and therapeutic mechanisms. Finally, molecular docking was applied to further confirm the effective components of SZRD, and a multivariate network for anxiolytic effects was constructed.

RESULTS

SZRD exerted anxiolytic effects by increasing the percentage of entries into open arms and the time spent in open arms; improving hippocampal 5-HT, GABA, and NE levels; and increasing serum corticosterone (CORT) and corticotropin-releasing hormone (CRH) levels caused by CRS challenge. Beside, SZRD exerted a sedative effect by decreasing sleep time and prolonging sleep latency with no muscle relaxation effect in CRS mice. A total of 110 components were identified in SZRD, 20 of which were absorbed in the blood. Twenty-one serum biomarkers involved in arachidonic acid, tryptophan, sphingolipid, and linoleic acid metabolism were identified after SZRD intervention. Finally, a multivariate network including prescription-effective components-targets-pathway of SZRD treating anxiety, including 11 effective components, 4 targets and 2 pathway was constructed.

CONCLUSION

The current study demonstrated that integrating chinmedomics and network pharmacology was a powerful approach to investigating the effective components and therapeutic mechanisms of SZRD and provided a solid basis for the quality marker (Q-marker) of SZRD.

Bioinformatics and computational chemistry approaches to explore the mechanism of the anti-depressive effect of ligustilide

Depression affects people with multiple adverse outcomes, and the side effects of antidepressants are troubling for depression sufferers. Aromatic drugs have been widely used to relieve symptoms of depression with fewer side effects. Ligustilide (LIG) is the main component of volatile oil in angelica sinensis, exhibiting an excellent anti-depressive effect. However, the mechanisms of the anti-depressive effect of LIG remain unclear. Therefore, this study aimed to explore the mechanisms of LIG exerting an anti-depressive effect. We obtained 12,969 depression-related genes and 204 LIG targets by a network pharmacology approach, which were intersected to get 150 LIG anti-depressive targets. Then, we identified core targets by MCODE, including MAPK3, EGF, MAPK14, CCND1, IL6, CASP3, IL2, MYC, TLR4, AKT1, ESR1, TP53, HIF1A, SRC, STAT3, AR, IL1B, and CREBBP. Functional enrichment analysis of core targets showed a significant association with PI3K/AKT and MAPK signaling pathways. Molecular docking showed strong affinities of LIG with AKT1, MAPK14, and ESR1. Finally, we validated the interactions between these proteins and LIG by molecular dynamics (MD) simulations. In conclusion, this study successfully predicted that LIG exerted an anti-depressive effect through multiple targets, including AKT1, MAPK14, and ESR1, and the pathways of PI3K/AKT and MAPK. The study provides a new strategy to explore the molecular mechanisms of LIG in treating depression.

Antidepressant effects of the traditional Chinese herbal formula Xiao-Yao-San and its bioactive ingredients

BACKGROUND

Depression is one of the most debilitating and severe psychiatric disorders and a serious public health concern. Currently, many treatments are indicated for depression, including traditional Chinese medicinal formulae such as Xiao-Yao-San (XYS), which has effective antidepressant effects in clinical and animal studies.

PURPOSE

To summarize current evidence of XYS in terms of the preclinical and clinical studies and to identify the multi-level, multi-approach, and multi-target potential antidepressant mechanisms of XYS and active components of XYS by a comprehensive search of the related electronic databases.

METHODS

The following electronic databases were searched from the beginning to April 2022: PubMed, MEDLINE, Web of Science, Google Scholar, and China National Knowledge Infrastructure.

RESULTS

This review summarizes the antidepressant mechanisms of XYS and its active ingredients, which are reportedly correlated with monoamine neurotransmitter regulation, synaptic plasticity, and hypothalamic-pituitary-adrenal axis, etc. CONCLUSION: XYS plays a critical role in the treatment of depression by the regulation of several factors, including the monoaminergic systems, hypothalamic-pituitary-adrenal axis, synaptic plasticity, inflammation, brain-derived neurotrophic factor levels, brain-gut axis, and other pathways. However, more clinical and animal studies should be conducted to further investigate the antidepressant function of XYS and provide more evidence and recommendations for its clinical application. Our review provides an overview of XYS and guidance for future research direction.

Dissecting the molecular mechanisms underlying the antidepressant activities of herbal medicines through the comprehensive review of the recent literatures

Depression is clinically defined as a mood disorder with persistent feeling of sadness, despair, fatigue, and loss of interest. The pathophysiology of depression is tightly regulated by the biosynthesis, transport and signaling of neurotransmitters [e.g., serotonin, norepinephrine, dopamine, or γ-aminobutyric acid (GABA)] in the central nervous system. The existing antidepressant drugs mainly target the dysfunctions of various neurotransmitters, while the efficacy of antidepressant therapeutics is undermined by different adverse side-effects. The present review aimed to dissect the molecular mechanisms underlying the antidepressant activities of herbal medicines toward the development of effective and safe antidepressant drugs. Our strategy involved comprehensive review and network pharmacology analysis for the active compounds and associated target proteins. As results, 45 different antidepressant herbal medicines were identified from various in vivo and in vitro studies. The antidepressant mechanisms might involve multiple signaling pathways that regulate neurotransmitters, neurogenesis, anti-inflammation, antioxidation, endocrine, and microbiota. Importantly, herbal medicines could modulate broader spectrum of the cellular pathways and processes to attenuate depression and avoid the side-effects of synthetic antidepressant drugs. The present review not only recognized the antidepressant potential of herbal medicines but also provided molecular insights for the development of novel antidepressant drugs.

Anti-depression effectiveness of essential oil from the fruits of Zanthoxylum bungeanum maxim. on chronic unpredictable mild stress-induced depression behavior in mice

The fruits of Zanthoxylum bungeanum Maxim. Was a popular traditional Chinese herbal medicine for pain relief, itching prevention, and diarrhea relief. The fruits of Zanthoxylum bungeanum Maxim. Essential oil (HEO) had an effect of improving anxiety and other emotional disorders. In this paper, we aim to systematically research the antidepressant effects of HEO on Chronic Mild Unpredictable Stimulation (CUMS) mice and explore the relevant molecular mechanisms. Experimental mice were exposed to CUMS for 8 weeks. Meanwhile, for 8 weeks, Sertraline hydrochloride (20 mg/kg/day) and HEO (50, 100, and 150 mg/kg/day) were administered by gavage. HEO treatment increased residence time of central zone in OFT and open-arm in EPM test but decreased immobility times in FST and TST. Moreover, HEO treatment improved the levels of 5-HT, DA, NE, and BDNF, but reduced CRF and CORT levels of the HPA axis in the hippocampus. Network pharmacology predicted the possible mechanisms for the antidepressant effects of HEO by regulation of PI3K/Akt signaling pathway. The mRNA expression of PI3K and Akt were increased, and immunofluorescence results in the hippocampus indicated that HEO treatment could increase the phosphorylation of PI3K and Akt. Besides, the viability of CORT-treated PC12 cells was significantly improved by HEO treatment. The AO-EB staining, MOMP analysis, and flow cytometry analysis results showed HEO inhibiting the CORT-induced apoptosis in PC12 cells significantly. Besides, the phosphorylation of PI3K and Akt in COTR-induced PC12 cells could increase by HEO treatment. In conclusion, HEO ameliorated depression behavior induced by CUMS, potentially via regulating HPA axis and activating PI3K/Akt signaling pathway to reduce neuronal apoptosis.

Medicine-food herb: Angelica sinensis, a potential therapeutic hope for Alzheimer's disease and related complications

Alzheimer's disease (AD) is a progressive neurodegenerative disease, which has brought a huge burden to the world. The current therapeutic approach of one-molecule-one-target strategy fails to address the issues of AD because of multiple pathological features of AD. Traditionally, the herb of Angelica sinensis (AS) comes from the root of an umbrella plant Angelica sinensis (Oliv.) Diels. As a typical medicine-food herb, studies have shown that AS can alleviate AD and AD-complications by multiple targets through the various foundations of pharmaceutical material and dietary supply basis. Therefore, this review summarizes the pharmacological effects of AS for the treatment of AD and AD-complications for the first time. AS contains many effective components, such as ligustilide, z-ligustilide, n-butylidenephthalide, α-pinene, p-cymene, myrcene, ferulic acid, vanillic acid and coniferyl ferulate. It is found that AS, AS-active compounds and AS-compound recipes mainly treat AD through neuroprotective, anti-inflammation, and anti-oxidant effects, improving mitochondrial dysfunction, anti-neuronal apoptosis, regulating autophagy, regulating intestinal flora and enhancing the central cholinergic system, which shows the multi-component and multi-target effect of AS. The role of dietary supplement components in AS for AD intervention is summarized, including vitamin B₁₂, folic acid, arginine, and oleic acid, which can improve the symptoms of AD. Besides, this review focuses on the safety and toxicity evaluation of AS, which provides a basis for its application. This review will provide further support for the research on AD and the application of medicine-food herb AS in a healthy lifestyle in the future.

Xiaoyaosan Ameliorates Chronic Restraint Stress-Induced Depression-Like Phenotype by Suppressing A2AR Signaling in the Rat Striatum

Depression is a common mental disorder characterized by pessimism and world-weariness. In our previous study, we found that Xiaoyaosan (XYS) could have antidepressive effects, however the underlying mechanisms remain unclear. Several studies have shown that adenosine A (2 A) receptor (A2AR) in the brain is a key point in the treatment of depression. Our present study aimed to investigate the effects of XYS on A2AR signaling in the striatum of rats exposed to chronic restraint stress (CRS). Ninety-six male Sprague–Dawley rats were randomly divided into 8 groups (control, model, negative control, XYS, A2AR antagonist, A2AR antagonist + XYS, A2AR agonist, A2AR agonist + XYS). The rats in the model group, XYS group, A2AR antagonist group and A2AR antagonist + XYS group were subjected to CRS for 3 h a day. The XYS decoction [2.224 g/(kg·d)] was intragastrical administered by oral gavage to the rats in the negative control group, XYS group, A2AR antagonist + XYS group, and A2AR agonist + XYS group. The rats in the A2AR antagonist group and A2AR antagonist + XYS group were treated with SCH 58261 [0.05 mg/(kg·d)], and the rats in the A2AR agonist and A2AR agonist + XYS group were treated with CGS 21680 [0.1 mg/(kg·d)]. These procedures were performed for 21 consecutive days. Behavioral studies including the open field test, elevated plus maze test, sucrose preference test and forced swimming test, were performed to examine depression-like phenotypes. Then, the effects of XYS on CRS- or A2AR agonist-induced striatal subcellular damage, microglial activation and A2AR signaling changes in the striatum were examined. Here, we report that XYS ameliorates depression-like phenotypes (such as body weight loss as well as depression- and anxiety-like behaviors) and improves synaptic survival and growth in the stratum of the CRS rats. Moreover, XYS reduces A2AR activity and suppresses hyper-activation of striatal microglia. The tissue and cellular effects of XYS were similar to those of the known A2AR antagonists. In conclusion, XYS alleviates depression in the CRS rats via inhibiting A2AR in the striatum.

Chinese Herbal Medicine in the Treatment of Depression in Parkinson’s Disease: From Molecules to Systems

Depression is one of the most common non-motor symptoms in patients with Parkinson’s disease (PD). Depression in PD (DPD) increases the disability rate and reduces the quality of life of PD patients and increases the caregiver burden. Although previous studies have explained the relationship between depression and PD through a variety of pathological mechanisms, whether depression is a precursor or an independent risk factor for PD remains unclear. Additionally, increasing evidence shows that conventional anti-PD drug therapy is not ideal for DPD. Chinese Herbal Medicine (CHM) prescriptions exhibit the characteristics of multi-target, multi-pathway, and multi-level treatment of DPD and may simultaneously improve the motor symptoms of PD patients through multiple mechanisms. However, the specific pharmacological mechanisms of these CHM prescriptions remain unelucidated. Here, we investigated the mechanisms of action of the active ingredients of single herbs predominantly used in CHM prescriptions for depression as well as the therapeutic effect of CHM prescriptions on DPD. This review may facilitate the design of new selective and effective treatment strategies for DPD.

Natural products for the treatment of stress-induced depression: Pharmacology, mechanism and traditional use

ETHNOPHARMACOLOGICAL RELEVANCE

Depression, one of the most common psychiatric disorders, is the fourth leading cause of long-term disability worldwide. A series of causes triggered depression, including psychological stress and conflict, as well as biological derangement, among which stress has a pivotal role in the development of depression. Traditional herbal medicine has been used for the treatment of various disorders including depression for a long history with multi-targets, multi-levels and multi-ways, attracting great attention from scholars. Recently, natural products have been commercialized as antidepressants which have become increasingly popular in the world health drug markets. Major research contributions in ethnopharmacology have generated and updated vast amount of data associated with natural products in antidepressant-like activity.

AIMS OF THE REVIEW

This review aims to briefly discuss the pathological mechanism, animal models of stress-induced depression, traditional use of herbal medicines and especially recapitulate the natural products with antidepressant activity and their pharmacological functions and mechanism of action, which may contribute to a better understanding of potential therapeutic effects of natural products and the development of promising drugs with high efficacy and low toxicity for the treatment of stress-induced depression.

MATERIALS AND METHODS

The contents of this review were sourced from electronic databases including PubMed, Sci Finder, Web of Science, Science Direct, Elsevier, Google Scholar, Chinese Knowledge On frastructure (CNKI), Wan Fang, Chinese Scientific and Technological Periodical Database (VIP) and Chinese Biomedical Database (CBM). Additional information was collected from Yao Zhi website (https://db.yaozh.com/). Data were obtained from April 1992 to June 2021. Only English language was applied to the search. The search terms were 'stress-induced depression', 'pathological mechanism' in the title and 'stress', 'depression', 'animal model' and 'natural products' in the whole text.

RESULTS

Stress-induced depression is related to the monoaminergic system, hypothalamic-pituitary-adrenal (HPA) axis, neuronal plasticity and a series of inflammatory factors. Four main types of animal models of stress-induced depression were represented. Fifty-eight bioactive phytochemical compounds, fifty-six herb medicines and five formulas from traditional Chinese medicine were highlighted, which exert antidepressant effects by inhibiting monoamine oxidase (MAO) reaction, alleviating dysfunction of the HPA axis and nerve injury, and possessing anti-inflammatory activities.

CONCLUSIONS

Natural products provide a large number of compounds with antidepressant-like effects, and their therapeutic impacts has been highlighted for a long time. This review summarized the pathological mechanism and animal models of stress-induced depression, and the natural products with antidepressant activity in particular, which will shed light on the action mechanism and clinical potential of these compounds. Natural products also have been a vital and promising source for future antidepressant drug discovery.