Research Progress on the Antidepressant Effects of Baicalin and Its Aglycone Baicalein: A Systematic Review of the Biological Mechanisms

Antidepressant activity of flavones from traditional Chinese medicine: a meta-analysis

CONTEXT

Flavones, the key active components in Traditional Chinese Medicine (TCM), have demonstrated antidepressant activity. Given the numerous animal studies conducted, a systematic analysis is essential to provide a valuable reference for future research.

OBJECT

This study investigated the antidepressant activity of flavones based on animal models and summarized the underlying mechanisms.

METHODS

We systematically searched 7 bibliographic Databases as of August 12, 2023, such as Web of Science, PubMed, China National Knowledge Infrastructure, etc. The meta-analysis was performed using either the random or fixed-effect model, supplemented by trial sequential analysis (TSA). The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to assess the quality of evidence.

RESULTS

A total of 25 studies involving 458 mice were included, identifying five flavones (baicalin, baicalein, apigenin, luteolin, vitexin) with antidepressant activity. Compared to the control group, flavones significantly reduced immobility time in forced swimming and tail suspension tests. Flavones also decreased serum and hippocampal levels of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α), reduced nuclear factor kappa B (NF-κB) levels, and increased brain-derived neurotrophic factor (BDNF) levels. Relative to the positive group, flavones raised IL-6, sucrose preference rate, and corticosterone (CORT) levels, with no significant differences in other factors. The TSA showed the efficacy of flavones for treating depression with adequate 'information size' for the primary outcome.

CONCLUSIONS

The results demonstrate that flavones exert protective effects against depression in mice, primarily by stimulating neurotrophic factors and modulating inflammatory pathways. These findings emphasize their potential as promising candidates for the development of novel antidepressant therapies.

The Effects of Combined Scutellaria and Saffron Supplementation on Mood Regulation in Participants with Mild-to-Moderate Depressive Symptoms: A Randomized, Double-Blind, Placebo-Controlled Study

Background/Objectives: The global prevalence of mental health disorders, particularly anxiety and depression, has increased significantly, with rates further elevated by the COVID-19 pandemic. Conventional pharmacological treatments, while effective, often lead to side effects that can impact patient adherence and quality of life. This has driven interest in safer, natural adjunctive therapies. Crocus sativus L. (Iridaceae) (saffron) and Scutellaria baicalensis Georgi (Lamiaceae) (scutellaria) have individually shown potential, in humans and animals, respectively, as mood regulators, with bioactive compounds that modulate neurotransmitter systems and possess anti-inflammatory and anxiolytic effects. This study aimed (1) to explore the efficacy and safety of scutellaria extracts in humans and (2) to test a possible synergistic effect when combining scutellaria and saffron on mood regulation in individuals experiencing mild-to-moderate depressive symptoms. Methods: In a randomized, double-blind, placebo-controlled trial, 180 participants with mild-to-moderate depressive symptoms were assigned to receive either scutellaria extract alone (SCUTELL'UP®), saffron extract alone (SAFFR'ACTIV®), a combination of scutellaria and saffron extracts (SAFFR'UP®), or a placebo for six weeks. The primary outcome was assessed using a standardized depression scale (Beck Depression Inventory). The secondary outcomes, including anxiety, emotional state, well-being level, and sleep quality, were all assessed using validated questionnaires. Safety and tolerability were evaluated throughout the study period. Results: The results confirmed the beneficial effects of saffron extract on depressive and anxious symptoms, as well as its role in improving sleep quality. For the first time in humans, scutellaria extract demonstrated a positive effect on mood regulation. Furthermore, a synergistic effect of the combination of these two extracts was identified, leading to enhanced improvements in depressive and anxious symptoms and emotional well-being among individuals with mild-to-moderate depression, compared to the placebo group. Minimal adverse effects were reported across all treatment groups. Conclusions: This natural adjunctive nutritional strategy offers a promising alternative for individuals seeking safer options for mental health support. Further research is warranted to exclude potential long-term side effects and to explore potential mechanisms of this combined supplementation.

Immune-related gene characterization and biological mechanisms in major depressive disorder revealed based on transcriptomics and network pharmacology

Background

Major depressive disorder (MDD) is a severe psychiatric disorder characterized by complex etiology, with genetic determinants that are not fully understood. The objective of this study was to investigate the pathogenesis of MDD and to explore its association with the immune system by identifying hub biomarkers using bioinformatics analyses and examining immune infiltrates in human autopsy samples.

Methods

Gene microarray data were obtained from the Gene Expression Omnibus (GEO) datasets GSE32280, GSE76826, GSE98793, and GSE39653. Our approach included differential expression analysis, weighted gene co-expression network analysis (WGCNA), and protein-protein interaction (PPI) network analysis to identify hub genes associated with MDD. Subsequently, gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Cytoscape plugin CluGO, and Gene Set Enrichment Analysis (GSEA) were utilized to identify immune-related genes. The final selection of immune-related hub genes was determined through the least absolute shrinkage and selection operator (Lasso) regression analysis and PPI analysis. Immune cell infiltration in MDD patients was analyzed using CIBERSORT, and correlation analysis was performed between key immune cells and genes. The diagnostic accuracy of the identified hub genes was evaluated using receiver operating characteristic (ROC) curve analysis. Furthermore, we conducted a study involving 10 MDD patients and 10 healthy controls (HCs) meeting specific criteria to assess the expression levels of these hub genes in their peripheral blood mononuclear cells (PBMCs). The Herbal Ingredient Target Database (HIT) was employed to screen for herbal components that target these genes, potentially identifying novel therapeutic agents.

Results

A total of 159 down-regulated and 51 up-regulated genes were identified for further analysis. WGCNA revealed 12 co-expression modules, with modules "darked", "darkurquoise" and "light yellow" showing significant positive associations with MDD. Functional enrichment pathway analysis indicated that these differential genes were associated with immune functions. Integration of differential and immune-related gene analysis identified 21 common genes. The Lasso algorithm confirmed 4 hub genes as potential biomarkers for MDD. GSEA analysis suggested that these genes may be involved in biological processes such as protein export, RNA degradation, and fc gamma r mediated cytotoxis. Pathway enrichment analysis identified three highly enriched immune-related pathways associated with the 4 hub genes. ROC curve analysis indicated that these hub genes possess good diagnostic value. Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) demonstrated significant expression differences of these hub genes in PBMCs between MDD patients and HCs. Immune infiltration analysis revealed significant correlations between immune cells, including Mast cells resting, T cells CD8, NK cells resting, and Neutrophils, which were significantly correlated with the hub genes expression. HIT identified one herb target related to IL7R and 14 targets related to TLR2.

Conclusions

The study identified four immune-related hub genes (TLR2, RETN, HP, and IL7R) in MDD that may impact the diagnosis and treatment of the disorder. By leveraging the GEO database, our findings contribute to the understanding of the relationship between MDD and immunity, presenting potential therapeutic targets.

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.

The effects of baicalin in depression: preclinical evidence construction based on meta-analysis

Background

Depression manifests as a mental disorder characterized by a low mood, suicidal tendencies, disturbances in sleep-wake cycles, psychomotor agitation, and pronounced feelings of hopelessness and anhedonia. Baicalin, a natural flavonoid compound, shows significant promise in alleviating depressive symptoms in animals. This study aims to assess the impact of baicalin on experimental models of depression.

Methods

A systematic search of electronic databases was conducted using the search terms "baicalin" AND "depression" OR "depressed" OR "anti-depression". Preclinical animal models representing experimental depression were included in the analysis. The risk of bias in the included studies was evaluated using the CAMARADES tools.

Results

Baicalin significantly increased sucrose preference test (SPT) [SMD= 21.31, 95%CI (16.32, 26.31), P < 0.00001]. mThe tail suspension test (TST) duration significantly decreased in the baicalin group compared to the model group [SMD = -39.3, 95%CI (-49.71, -28.89), P < 0.0001]. Furthermore, baicalin reduced immobility time in rats subjected to the forced swim test (FST) [SMD = -39.73, 95%CI (-48.77, -30.69) P < 0.0001]. Compared to the model group, baicalin treatment also significantly increased the frequency of crossings in the open field test (OFT) [SMD = 32.44, 95%CI (17.74, 47.13), P < 0.00001].

Conclusion

Baicalin significantly improves the manifestations of depressive symptoms. The effect of baicalin against depression is exerted through its anti-inflammatory actions, inhibition of oxidative stress, regulation of the HPA axis, and restoration of neuroplasticity. Future studies will be needed to further explore how these promising preclinical findings can be translated into clinical treatment for depression.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023472181.

Preparation, characterisation and in vitro anti-inflammatory activity of Baicalin microsponges

Baicalin, a flavonoid extracted from traditional Chinese medicine, Scutellaria baicalensis has significant anti-inflammatory effects. Microsponges are drug delivery systems that improve drug stability and slow the release rate. The combination of baicalin and the microsponges produced a new and stable system for its delivery, resulting in a novel formulation of baicalin. Baicalin microsponges (BM) were prepared using the quasi-emulsion solvent diffusion method. Effects of the mass ratio of the polymer (ethylcellulose) to baicalin, the concentration of the emulsifier polyvinyl alcohol (PVA), the stirring speed on the encapsulation efficiency (EE), and yield of the microsponges were investigated by combining the one-factor test and Box-Behnken design (BBD). The preparation process was standardised using 2.61:1 mass ratio of ethyl cellulose to baicalin, 2.17% concentration of PVA, with stirring at 794 rpm. Optimised BM formulations were evaluated for the parameters of EE (54.06 ± 3.02)% and yield of (70.37 ± 2.41)%, transmission electron microscopy (TEM), and in vitro cell evaluation. Results of the in vitro anti-inflammatory assay showed that baicalin microsponges-pretreated-lipopolysaccharide (LPS)-induced RAW264.7, mouse macrophages showed reduced inflammatory response, similar to that seen in baicalin-treated macrophages.

Flavonoids with Anti-Angiogenesis Function in Cancer

The formation of new blood vessels, known as angiogenesis, significantly impacts the development of multiple types of cancer. Consequently, researchers have focused on targeting this process to prevent and treat numerous disorders. However, most existing anti-angiogenic treatments rely on synthetic compounds and humanized monoclonal antibodies, often expensive or toxic, restricting patient access to these therapies. Hence, the pursuit of discovering new, affordable, less toxic, and efficient anti-angiogenic compounds is imperative. Numerous studies propose that natural plant-derived products exhibit these sought-after characteristics. The objective of this review is to delve into the anti-angiogenic properties exhibited by naturally derived flavonoids from plants, along with their underlying molecular mechanisms of action. Additionally, we summarize the structure, classification, and the relationship between flavonoids with their signaling pathways in plants as anti-angiogenic agents, including main HIF-1α/VEGF/VEGFR2/PI3K/AKT, Wnt/β-catenin, JNK1/STAT3, and MAPK/AP-1 pathways. Nonetheless, further research and innovative approaches are required to enhance their bioavailability for clinical application.

Antidepressant-like Effect of Oroxylum indicum Seed Extract in Mice Model of Unpredictable Chronic Mild Stress

Major depressive disorder (MDD) is one life-threatening disorder that is prevalent worldwide. The evident etiology of this disease is still poorly understood. Currently, herbal medicine is gaining more interest as an alternative antidepressant. Oroxylum indicum, which is used in traditional medicine and contains a potential antidepressive compound, baicalein, could have an antidepressive property. An in vitro monoamine oxidase-A (MAO-A) inhibitory assay was used to preliminarily screening for the antidepressant effect of O. indicum seed (OIS) extract. Mice were subjected to unpredictable chronic mild stress (UCMS) for 6 weeks, and the daily administration of OIS extract started from week 4. The mechanisms involved in the antidepressive activity were investigated. The OIS extract significantly alleviated anhedonia and despair behaviors in the UCMS-induced mouse model via two possible pathways: (i) it normalized the HPA axis function via the restoration of negative feedback (decreased FKBP5 and increased GR expressions) and the reduction in the glucocorticoid-related negative gene (SGK-1), and (ii) it improved neurogenesis via the escalation of BDNF and CREB expressions in the hippocampus and the frontal cortex. In addition, an HPLC analysis of the OIS extract showed the presence of baicalin, baicalein, and chrysin as major constituents. All of the results obtained from this study emphasize the potential of OIS extract containing baicalin and baicalein as an effective and novel alternative treatment for MDD.