The therapeutic potential of traditional Chinese medicine in depression: Targeting adult hippocampal neurogenesis

Kaempferol improves depression-like behaviors through shifting microglia polarization and suppressing NLRP3 via tilting the balance of PPARγ and STAT1 signaling

BACKGROUND

The pathogenesis of depression is largely influenced by dyshomeostasis of neuroinflammation regulated by microglia M1/M2 polarization, and NLRP3 inflammasome acts critical roles in shifting microglia polarization. Kaempferol (Kae), a major flavonoid in edible plants, possesses anti-inflammation and anti-depression capacity, but its underlying cellular and molecular mechanisms of antidepressive effect have not yet fully explored.

METHODS

In vivo studies with lipopolysaccharide (LPS)-induced depressive mice were carried out to evaluate antidepressant effect of Kae. In vitro, BV2 microglia cell line stimulated by LPS along with IFN-γ to detect pharmacological effects of Kae on microglia polarization and NLRP3. Based on two depression-related GEO datasets (GSE54570 and GSE54568) and the potential targets of Kae obtained from GeneCards database, enrichment analysis and protein-protein interaction (PPI) network construction reveal potential therapeutic targets of Kae for depression. Then the precise antidepressant mechanisms of Kae were verified by western blot and immunofluorescent staining in vivo and vitro.

RESULTS

Our results showed that Kae significantly improves LPS-induced depressive behaviors and alleviates neuroinflammation in prefrontal cortex. Moreover, Kae obviously shifted microglia polarization to M2 phenotype, and also suppressed NLRP3 in prefrontal cortex and BV2. Enrichment analysis and PPI network construction suggested PPARγ and STAT1 signaling are related to regulation of NLRP3 in depression. Furtherly, Kae remarkably enhanced PPARγ activation and inhibited nuclear translocation of p-STAT1 in microglia of prefrontal cortex and BV2. Importantly, pre-incubation with PPARγ antagonist T0070907 or overexpression with CASTAT1 (constitutively active STAT1) both prevented pharmacologic effects of Kae on shifting microglia polarization and suppressing NLRP3 in BV2. Noteworthily, T0070907 significantly blocked the inhibitory effect of Kae on STAT1 while overexpression with CASTAT1 abolished the effect of Kae on PPARγ activation in BV2. Above results suggested that pharmacologic effects of Kae on microglia polarization and NLRP3 are dependent on the balance of counter-regulatory PPARγ and STAT1 signaling.

CONCLUSION

Our results indicated that the shifting microglia polarization and suppression of NLRP3 via tilting the balance of PPARγ and STAT1 signaling may be the antidepressant mechanism of Kae, which provides a novel perspective for elucidating antidepressive effect of Kae.

Natural products that alleviate depression: The putative role of autophagy

Major depressive disorder (MDD) is a common mental disorder that severely disrupts psychosocial function and decreases the quality of life. Although the pathophysiological mechanism underlying MDD is complex and remains unclear, emerging evidence suggests that autophagy dysfunction plays a role in MDD occurrence and progression. Natural products serve as a major source of drug discovery and exert tremendous potential in developing antidepressants. Recently published reports are paying more attention on the autophagy regulatory effect of antidepressant natural products. In this review, we comprehensively discuss the abnormal changes occurred in multiple autophagy stages in MDD patients, and animal and cell models of depression. Importantly, we emphasize the regulatory mechanism of antidepressant natural products on disturbed autophagy, including monomeric compounds, bioactive components, crude extracts, and traditional Chinese medicine formulae. Our comprehensive review suggests that enhancing autophagy might be a novel approach for MDD treatment, and natural products restore autophagy homeostasis to facilitate the renovation of mitochondria, impede neuroinflammation, and enhance neuroplasticity, thereby alleviating depression.

Reveal the potent antidepressant effects of Zhi-Zi-Hou-Pu Decoction based on integrated network pharmacology and DDI analysis by deep learning

Background and objective

The multi-targets and multi-components of Traditional Chinese medicine (TCM) coincide with the complex pathogenesis of depression. Zhi-Zi-Hou-Pu Decoction (ZZHPD) has been approved in clinical medication with good antidepression effects for centuries, while the mechanisms under the iceberg haven't been addressed systematically. This study explored its inner active ingredients - potent pharmacological mechanism - DDI to explore more comprehensively and deeply understanding of the complicated TCM in treatment.

Methods

This research utilized network pharmacology combined with molecular docking to identify pharmacological targets and molecular interactions between ZZHPD and depression. Verification of major active compounds was conducted through UPLC-Q-TOF-MS/MS and assays on LPS-induced neuroblastoma cells. Additionally, the DDIMDL model, a deep learning-based approach, was used to predict DDIs, focusing on serum concentration, metabolism, effectiveness, and adverse reactions.

Results

The antidepressant mechanisms of ZZHPD involve the serotonergic synapse, neuroactive ligand-receptor interaction, and dopaminergic synapse signaling pathways. Eighteen active compounds were identified, with honokiol and eriocitrin significantly modulating neuronal inflammation and promoting differentiation of neuroimmune cells through genes like COMT, PI3KCA, PTPN11, and MAPK1. DDI predictions indicated that eriocitrin's serum concentration increases when combined with hesperidin, while hesperetin's metabolism decreases with certain flavonoids. These findings provide crucial insights into the nervous system's effectiveness and potential cardiovascular or nervous system adverse reactions from core compound combinations.

Conclusions

This study provides insights into the TCM interpretation, drug compatibility or combined medication for further clinical application or potential drug pairs with a cost-effective method of integrated network pharmacology and deep learning.

NMR-based metabolomics approach to study the effect and related molecular mechanisms of Saffron essential oil against depression

Depression currently ranks as the fourth leading cause of disability globally, affecting approximately 20% of the world's population. we established a chronic restraint stress (CRS) induced depression model in mice and employed fluoxetine as a reference drug. We assessed the therapeutic potential of saffron essential oil (SEO) and elucidated its underlying mechanisms through behavioral indices and NMR-based metabolomic analysis. The findings indicate that SEO ameliorates behavioral symptoms of depression, such as the number of entries into the central area, fecal count, latency to immobility, and duration of immobility in both the Tail Suspension Test (TST) and the Forced Swim Test (FST), along with correcting the dysregulation of 5-serotonin. Metabolomic investigations identified sixteen potential biomarkers across the liver, spleen, and kidneys. SEO notably modulated nine of these biomarkers: dimethylglycine, glycerol, adenosine, β-glucose, α-glucose, uridine, mannose, sarcosine, and aspartate, with glycerol emerging as a common biomarker in both the liver and spleen. Pathway analysis suggests that these biomarkers participate in glycolysis, glycine serine threonine metabolism, and energy metabolism, potentially implicating a role in neural regulation. In summary, SEO effectively mitigates depressive-like behaviors in CRS mice, predominantly via modulation of glycolysis, amino acid metabolism, and energy metabolism, and potentially exerts antidepressant effects through neural regulation. Our study offers insights into small molecule metabolite alterations in CRS mice through a metabolomics lens, providing evidence for the antidepressant potential of plant essential oils and contributing to our understanding of the mechanisms of traditional Chinese medicine in treating depression.

Progress of research on the treatment of depression by traditional Chinese medicine prescriptions

Depression is a common psychiatric disorder that belongs to the category of "Depression Syndrome" in traditional Chinese medicine (TCM), and its etiology and pathogenesis are complex and unclear. It is characterized by high prevalence, high disability rate, and high recurrence rate, which seriously affect human health, and its treatment has become a research hotspot worldwide. At present, the antidepressants commonly used in the clinic are mainly Western medicine (WM), but there are problems such as frequent side effects and poor efficacy. Studies have found that the use of TCM prescriptions in the treatment of depression can achieve the same effect as WM; and when TCM prescriptions are combined with WM, the efficacy can be enhanced while the adverse effects of WM can be reduced. Pharmacological studies related to the treatment of depression with traditional Chinese medicine prescriptions (TCMPs) have focused on the neurobiochemical system, gut microbes, and energy metabolism in mitochondria. No one has yet reviewed the pharmacological mechanism of TCMPs for depression. So, this paper reviews the pharmacological mechanism of TCMPs for depression from the perspective of TCMPs, introduces the progress of research on classical TCMPs for depression and their antidepressant mechanism. This article aims to promote the application of TCMPs in the clinic and provide a new therapeutic idea for the clinical treatment of depression.

Du-moxibustion ameliorates depression-like behavior and neuroinflammation in chronic unpredictable mild stress-induced mice

BACKGROUND

Neuroinflammation is involved in the advancement of depression. Du-moxibustion can treat depression. Here, we explored whether Du-moxibustion could alleviate neuroglia-associated neuro-inflammatory process in chronic unpredictable mild stress (CUMS) mice.

METHODS

C57BL/6J mice were distributed into five groups. Except for the CON group, other four groups underwent CUMS for four consecutive weeks, and Du-moxibustion was given simultaneously after modeling. Behavioral tests were then carried out. Additionally, Western blot was conducted to measure the relative expression levels of high-mobility group box 1 (HMGB1), toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor-kappa B (NF-κB). Immunofluorescence was employed to evaluate the positive cells of ionized calcium binding adapter molecule 1 (Iba-1) and glial fibrillary acidic protein (GFAP). Furthermore, interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) were analyzed using an ELISA assay.

RESULTS

We found that CUMS induced depression-like behaviors, such as reduced sucrose preference ratio, decreased locomotor and exploratory activity, decreased the time in open arms and prolonged immobility. Furthermore, versus the CON group, the expression of HMGB1, TLR4, MyD88, NF-κB, positive cells of Iba-1, IL-1β and TNF-α were increased but positive cells of GFAP were decreased in CUMS group. However, the detrimental effects were ameliorated by treatment with CUMS+FLU and CUMS+DM.

LIMITATIONS

A shortage of this study is that only CUMS model of depression were used, while other depression model were not included.

CONCLUSIONS

Du-moxibustion alleviates depression-like behaviors in CUMS mice mainly by reducing neuroinflammation, which offers novel insights into the potential treatment of depression.

Network pharmacology and experimental evidence: ERK/CREB/BDNF signaling pathway is involved in the antidepressive roles of Kaiyu Zhishen decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Major Depressive Disorder (MDD) emerges as a complex psychosomatic condition, notable for its considerable suicidality and mortality rates. Increasing evidence suggests the efficacy of Chinese herbal medicine in mitigating depression symptoms and offsetting the adverse effects associated with conventional Western therapeutics. Notably, clinical trials have revealed the adjunctive antidepressant potential of Kaiyu Zhishen Decoction (KZD) alongside Western medication. However, the standalone antidepressant efficacy of KZD and its underlying mechanisms merit in-depth investigation.

AIM OF THE STUDY

This research aims to elucidate the impact of KZD on MDD and delineate its mechanistic pathways through integrated network pharmacological assessments and empirical in vitro and in vivo analyses.

MATERIALS AND METHODS

To ascertain the optimal antidepressant dosage and mechanism of KZD, a Chronic Unpredictable Mild Stress (CUMS)-induced depression model in mice was established to evaluate depressive behaviors. High-Performance Liquid Chromatography (HPLC) and network pharmacological approaches were employed to predict KZD's antidepressant mechanisms. Subsequently, hippocampal samples were subjected to 4D-DIA proteomic sequencing and validated through Western blot, immunofluorescence, Nissl staining, and pathway antagonist applications. Additionally, cortisol-stimulated PC12 cells were utilized to simulate neuronal damage, analyzing protein and mRNA levels of MAPK-related signals and cell proliferation markers.

RESULTS

The integration of network pharmacology and HPLC identified kaempferol and quercetin as KZD's principal active compounds for MDD treatment. Proteomic and network pharmacological KEGG pathway analyses indicated the MAPK signaling pathway as a critical regulatory mechanism for KZD's therapeutic effect on MDD. KZD was observed to mitigate CUMS-induced upregulation of p-ERK/ERK, CREB, and BDNF protein expressions in hippocampal cells by attenuating oxidative stress, thereby ameliorating neuronal damage and exerting antidepressant effects. The administration of PD98059 counteracted KZD's improvements in depression-like behaviors and downregulated p-ERK/ERK and BDNF protein expressions in the hippocampus.

CONCLUSIONS

This investigation corroborates KZD's pivotal, dose-dependent role in antidepressant activity. Both in vivo and in vitro experiments demonstrate KZD's capacity to modulate the ERK-CREB-BDNF signaling pathway by diminishing ROS expression induced by oxidative stress, enhancing neuronal repair, and thus, manifesting antidepressant properties. Accordingly, KZD represents a promising herbal candidate for further antidepressant research.

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

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

The antidepressive mechanism of Longya Lilium combined with Fluoxetine in mice with depression-like behaviors

Traditional Chinese medicine is one of the most commonly used complementary and alternative medicine therapies for depression. Integrated Chinese-western therapies have been extensively applied in numerous diseases due to their superior efficiency in individual treatment. We used the meta-analysis, network pharmacology, and bioinformatics studies to identify the putative role of Longya Lilium combined with Fluoxetine in depression. Depression-like behaviors were mimicked in mice after exposure to the chronic unpredictable mild stress (CUMS). The underlying potential mechanism of this combination therapy was further explored based on in vitro and in vivo experiments to analyze the expression of COX-2, PGE2, and IL-22, activation of microglial cells, and neuron viability and apoptosis in the hippocampus. The antidepressant effect was noted for the combination of Longya Lilium with Fluoxetine in mice compared to a single treatment. COX-2 was mainly expressed in hippocampal CA1 areas. Longya Lilium combined with Fluoxetine reduced the expression of COX-2 and thus alleviated depression-like behavior and neuroinflammation in mice. A decrease of COX-2 curtailed BV-2 microglial cell activation, inflammation, and neuron apoptosis by blunting the PGE2/IL-22 axis. Therefore, a combination of Longya Lilium with Fluoxetine inactivates the COX-2/PGE2/IL-22 axis, consequently relieving the neuroinflammatory response and the resultant depression.

MiR-182-5p: A Novel Biomarker in the Treatment of Depression in CSDS-Induced Mice

BACKGROUND

Depression is a neuropsychiatric disease with a high disability rate and mainly caused by the chronic stress or genetic factors. There is increasing evidence that microRNAs (miRNAs) play a critical role in the pathogenesis of depression. However, the underlying molecular mechanism for the pathophysiology of depression of miRNA remains entirely unclear so far.

METHODS

We first established a chronic social defeat stress (CSDS) mice model of depression, and depression-like behaviors of mice were evaluated by a series of behavioral tests. Next, we detected several abundantly expressive miRNAs suggested in previous reports to be involved in depression and found miR-182-5p was selected as a candidate for analysis in the hippocampus. Then western blotting and immunofluorescence were used together to examine whether adeno-associated virus (AAV)-siR-182-5p treatment alleviated chronic stress-induced decrease in hippocampal Akt/GSK3β/cAMP-response element binding protein (CREB) signaling pathway and increase in neurogenesis impairment and neuroinflammation. Furthermore, CREB inhibitor was adopted to examine if blockade of Akt/GSK3β/CREB signaling pathway abolished the antidepressant actions of AAV-siR-182-5p in mice.

RESULTS

Knockdown of miR-182-5p alleviated depression-like behaviors and impaired neurogenesis of CSDS-induced mice. Intriguingly, the usage of agomiR-182-5p produced significant increases in immobility times and aggravated neuronal neurogenesis damage of mice. More importantly, it suggested that 666-15 blocked the reversal effects of AAV-siR-182-5p on the CSDS-induced depressive-like behaviors in behavioral testing and neuronal neurogenesis within hippocampus of mice.

CONCLUSIONS

These findings indicated that hippocampal miR-182-5p/Akt/GSK3β/CREB signaling pathway participated in the pathogenesis of depression, and it might give more opportunities for new drug developments based on the miRNA target in the clinic.

What can traditional Chinese medicine do for adult neurogenesis?

Adult neurogenesis plays a crucial role in cognitive function and mood regulation, while aberrant adult neurogenesis contributes to various neurological and psychiatric diseases. With a better understanding of the significance of adult neurogenesis, the demand for improving adult neurogenesis is increasing. More and more research has shown that traditional Chinese medicine (TCM), including TCM prescriptions (TCMPs), Chinese herbal medicine, and bioactive components, has unique advantages in treating neurological and psychiatric diseases by regulating adult neurogenesis at various stages, including proliferation, differentiation, and maturation. In this review, we summarize the progress of TCM in improving adult neurogenesis and the key possible mechanisms by which TCM may benefit it. Finally, we suggest the possible strategies of TCM to improve adult neurogenesis in the treatment of neuropsychiatric disorders.

Neferine alleviates chronic stress-induced depression by regulating monoamine neurotransmitter secretion and gut microbiota structure

Neferine (Nef) might possess anti-depressive properties; however, its therapeutic effects are yet to be elucidated. Therefore, in this study, we aimed to explore the anti-depressant property of Nef using a mouse model of chronic stress-induced depression. Fifteen depression-prone mice were randomly selected and divided into three groups, namely, the model, Nef, and fluoxetine (Flu) groups. We observed that in tail suspension and forced swimming tests, the Nef and Flu treatments significantly decreased the immobility time of the depressed mice, and increased their sucrose preference indices. Moreover, both Nef and Flu treatments induced significant increases in the levels of anti-depressant neurotransmitters, including dopamine (DA), serotonin (5-HT), and norepinephrine (NE), and also reduced pathological damage to the hippocampus of the depressed mice. Incidentally, Illumina MiSeq sequencing analysis demonstrated that the relative abundance of Lactobacillus in the intestinal microbiota of depressed mice was restored after Nef/Flu treatment. Moreover, colonic Lactobacillus abundance was positively correlated with the levels of DA, 5-HT, and NE in the hippocampus of the mice. In conclusion, Nef improved monoamine neurotransmitter secretion and modulated the intestinal flora structure, particularly the abundance of Lactobacillus. Hence, it showed considerable anti-depressant potential, and might be a prospective anti-depressant therapeutic agent.

Antidepressant Potential of Quercetin and its Glycoside Derivatives: A Comprehensive Review and Update

Depression is a global health problem with growing prevalence rates and serious impacts on the daily life of patients. However, the side effects of currently used antidepressants greatly reduce the compliance of patients. Quercetin is a flavonol present in fruits, vegetables, and Traditional Chinese medicine (TCM) that has been proved to have various pharmacological effects such as anti-depressant, anti-cancer, antibacterial, antioxidant, anti-inflammatory, and neuroprotective. This review summarizes the evidence for the pharmacological application of quercetin to treat depression. We clarified the mechanisms of quercetin regulating the levels of neurotransmitters, promoting the regeneration of hippocampal neurons, improving hypothalamic-pituitary-adrenal (HPA) axis dysfunction, and reducing inflammatory states and anti-oxidative stress. We also summarized the antidepressant effects of some quercetin glycoside derivatives to provide a reference for further research and clinical application.

Non-linear association between Mediterranean diet and depressive symptom in U.S. adults: A cross-sectional study

The Mediterranean diet (MED), a dietary pattern rich in fruits and vegetables, whole grains, legumes, nuts, fish, and olive oil, has anti-oxidative and anti-inflammatory effects. Although some data suggest that MED adherence is associated with decreased manifestation of depressive symptoms, it remains necessary to further analyze this apparent non-linear association as well as the influence of different factors on the relationship between MED and depression. Here, we investigated associations between the alternate MED (aMED) score and depressive symptom via multivariate logistic regression, weighted generalized additive (GAM) and two-step linear regression models, analyzing data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES). The most important factor relevant to aMED score that contributed to the prevalence of depressive symptom was assessed using random forest. Furthermore, we examined whether the relationship between aMED score and depressive symptom differs by age, race, sex, socioeconomic variables, lifestyle- and health-related variables, and chronic medical conditions, via subgroup analyses. A total of 19,477 participants (20-80 years of age) were included in this cross-sectional study. In crude and adjusted (1-5) multivariate logistic regression models, increased aMED score was noted to associate with non-depressive status, as defined using the Patient Health Questionnaire-9 (P < 0.05). Data analyses via GAM and two-piecewise linear regression revealed a non-linear association between aMED and depressive symptom, which had an inflection point of 3. Random forest results revealed that vegetable score contributes greatest to the relationship between aMED and depressive symptom. Subgroup analyses revealed that aMED score is significantly negatively related with depressive symptom in most different populations (P < 0.05) with the exception of high annual income, diabetes, borderline blood glucose level and Parkinson's disease (PD) (P > 0.05). In conclusion, we observed a non-linear association between aMED score and depressive symptom. Further studies are needed to validate our results.