The antidepressant effects of hesperidin on chronic unpredictable mild stress-induced mice

HMGB1: Different secretion pathways with pivotal role in epilepsy and major depressive disorder

High-mobility group box 1 (HMGB1) protein is a highly prevalent protein that, once it is translocated to an extracellular site, can contribute to the pathogenesis of autoimmune and inflammatory responses, including epilepsy and depression. The conditions needed for release are associated with the production of multiple isoforms, and this translocation may occur in response to both immune cell activation and cell death. HMGB1 has been shown to interact with different mediators, including exportin 1, notch receptors, mitogen-activated protein kinase, STAT, tumor protein 53, and inflammasomes. Furthermore, as a crucial inflammatory mediator, HMGB1 has demonstrated upregulated expression and a higher percentage of translocation from the nucleus to the cytoplasm, acting on downstream receptors such as toll-like receptor 4 and receptor for advanced glycation end products, thereby activating interleukin-1 beta and nuclear factor kappa-B, intensifying inflammatory responses. In this review, we aim to discuss the different molecular interactions for the secretion of HMGB1 along with its pivotal role in epilepsy and major depressive disorder.

A comprehensive review on the impact of polyphenol supplementation and exercise on depression and brain function parameters

The objective of this review study is to examine the combined antidepressant effects of exercise and polyphenol supplementation, with a focus on specific polyphenolic compounds such as crocin, curcumin, and quercetin, as well as different forms of physical exercise, including aerobic and resistance training. The research examines how these interventions influence depressive-like behaviors, cognitive function, and neurochemical markers in animal models and human participants. The findings demonstrate that both exercise and polyphenols independently contribute to mood enhancement, reduced anxiety, and improved cognitive function through mechanisms such as neurogenesis, neurotransmitter modulation, and anti-inflammatory effects. Notably, the combined interventions showed a synergistic effect, providing more significant benefits in reducing symptoms of depression and anxiety, enhancing cognitive performance, and supporting overall mental well-being. These results suggest that integrating exercise and polyphenol supplementation could be a promising non-pharmacological approach to managing depression and related disorders.

Exploring the association between BDNF related signaling pathways and depression: A literature review

Depression is a debilitating mental disease that inflicts significant harm upon individuals and society, yet effective treatment options remain elusive. At present, the pathogenesis of multiple depression is not fully clear, but its occurrence can be related to biological or environmental pathways, among which Brain-derived neurotrophic factor (BDNF) can unequivocally act on two downstream receptors, tyrosine kinase receptor (TrkB) and the p75 neurotrophin receptor (p75NTR), then affect the related signal pathways, affecting the occurrence and development of depression. Accumulating studies have revealed that BDNF-related pathways are critical in the pathophysiology of depression, and their interaction can further influence the efficacy of depression treatment. In this review, we mainly summarized the signaling pathways associated with BDNF and classified them according to different receptors and related molecules, providing promising insights and future directions in the treatment of depression.

Hesperidin alleviated dendritic spines through inhibiting ferritinophagy via HERC2-NCOA4 ubiquitination in CUMS mice

BACKGROUND

Depression has been linked to ferritinophagy-induced synaptic damage, which affects the emotional circuitry and can ultimately lead to depressive symptoms. It has been suggested that Hesperidin might improve depression disorders. However, the relationship between the therapeutic effects of the sympathetic nervous system in alleviating depression-like behaviors and ferritinophagy is still unknown.

PURPOSE

The objective of this study is to investigate the possible impact of Hesperidin in alleviating dendritic spines through the inhibition of ferritinophagy via HERC2-NCOA4 ubiquitination in mice exposed to chronic unpredictable mild stress (CUMS).

METHODS

C57BL/6 and NCOA4+/+ mice were exposed to CUMS for 42 days. During the last 3 weeks of the CUMS procedure, the mice were administered Hesperidin (50, 100, 200 g/kg/d) or fluoxetine (10 mg/kg/d) once daily. Following the behavioral tests, Golgi staining, tissue iron concentration test, and perls staining were conducted to assess the therapeutic effect of Hesperidin. Additionally, ultrahigh-performance liquid chromatography-high-resolution tandem mass spectrometry (UPLC-Q-TOF/MS) and ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was utilized to analyze the metabolic components of Hesperidin in both blood and brain tissue. To investigate mechanism of Hesperidin, the cells were subjected to different concentrations of Hesperidin (25, 50, 100 µM), its metabolites (Eriodictyol (10, 20, 50 µM), Homoeriodictyol (0.1, 0.5, 1 µM)) and si-HERC2. Furthermore, HERC2-NCOA4 ubiquitination, and ferritinophagy-related proteins was explored through techniques such as western blot, immunofluorescence, co-immunoprecipitation, and molecular docking.

RESULTS

Hesperidin has demonstrated the potential to alleviate symptoms of depression by regulating dendritic spines through the inhibition of NCOA4-ferritinophagy, while NCOA4 overexpression could reverse these results. Importantly, the content of Hesperidin metabolites (Homoeriodictyol and Eriodictyol) was relatively high in brain tissue. The Hesperidin and its metabolites, Eriodictyol and Homoeriodictyol, were able to regulate GluR2 and SYN protein expression. Additionally, they inhibited ferritinophagy involving NCOA4, P62, LC3, and FTH. but this phenomenon was reversed by si-HERC2 following Hesperidin and its metabolite administration. Furthermore, the binding of HERC2 and NCOA4 protein was found to be inhibited by Hesperidin and its metabolites.

CONCLUSIONS

Hesperidin alleviated dendritic spines through inhibiting ferritinophagy via HERC2-NCOA4 ubiquitination in CUMS mice.

Phytochemistry, pharmacological properties and pharmacokinetics of Citri Reticulatae Pericarpium: A systematic review

ETHNOPHARMACOLOGICAL RELEVANCE

Citri Reticulatae Pericarpium (CRP), known as Chen Pi in China, is the most commonly used medicine for regulating qi. As a traditional medicine, CRP has been extensively used in the clinical treatment of nausea, vomiting, cough and phlegm for thousands of years. It is mainly distributed in Guangdong, Sichuan, Fujian and Zhejiang in China. Due to its high frequency of use, many scholars have conducted a lot of research on it and the related chemical constituents it contains. In this review, the research progress on phytochemistry, pharmacology, pharmacokinetics and toxicology of CRP are summarized.

AIM OF THE REVIEW

The review aims to sort out the methods of extraction and purification, pharmacological activities and mechanisms of action, pharmacokinetics and toxicology of the chemical constituents in CRP, in order to elaborate the future research directions and challenges for the study of CRP and related chemical constituents.

MATERIALS AND METHODS

Valid and comprehensive relevant information was collected from China National Knowledge Infrastructure, Web of Science, PubMed and so on.

RESULTS

CRP contains a variety of compounds, of which terpenes, flavonoids and alkaloids are the main components, and they are also the primary bioactive components that play a pharmacological role. Flavonoids and terpenes are extracted and purified by aqueous and alcoholic extraction methods, assisted by ultrasonic and microwave extraction, in order to achieve higher yields with less resources. Pharmacological studies have shown that CRP possesses a variety of highly active chemical components and a wide range of pharmacological activities, including anti-tumor, anti-inflammatory, immunomodulatory, hepatoprotective, therapeutic for cardiovascular-related disorders, antioxidant, antibacterial, and neuroprotective effects.

CONCLUSIONS

There is a diversity in the chemical compositions of CRP, which have multiple biological activities and promising applications. However, the pharmacological activities of CRP are mainly dependent on the action of its chemical components, but the relationship between the structure of chemical components and the biological effects has not been thoroughly investigated, and therefore, the structure-activity relationship is an issue that needs to be elucidated urgently. In addition, the pharmacokinetic studies of the relevant components can be further deepened and the correlation studies between pharmacological effects and syndromes of TCM can be expanded to ensure the effectiveness and rationality of CRP for human use.

Flavonoids against depression: a comprehensive review of literature

Background

Depression is a state of low mood and aversion to activity, which affects a person's thoughts, behavior, motivation, feelings, and sense of wellbeing. Pharmacologic therapies are still the best effective treatment of depression. Still, most antidepressant drugs have low efficacy and delayed onset of therapeutic action, have different side effects, and even exacerbate depression. Such conditions make it possible to look for alternatives. Consequently, we decided to summarize the impact of flavonoids on depression in this review.

Methods

We searched scientific databases such as SCOPUS, PubMed, and Google Scholar to find relevant studies until July 2022.

Results

A wide variety of natural components have been shown to alleviate depression, one of which is flavonoids. Due to the growing tendency to use natural antidepressant drugs, scientific studies are increasingly being conducted on flavonoids. This study aims to review the latest scientific researches that indicate the antidepressant potential of flavonoids. Various mechanisms include neurotransmitter system modulation and dopaminergic, noradrenergic, and serotonergic pathways regulation in the central nervous system. Different compounds of flavonoids have antidepressant properties in vivo or in vitro experiments or clinical trials and can be used as alternative and complementary treatments for depression. In general, it was observed that there were no severe side effects.

Conclusion

Our study proves the antidepressant potential of flavonoids, and considering the limited side effects, they can be used as complementary medicine for depressed patients.

Vanillic Acid Protects PC12 Cells from Corticosterone-Induced Neurotoxicity via Regulating Immune and Metabolic Dysregulation Based on Computational Metabolomics

Vanillic acid is widely used in the food industry and exhibits an excellent neuroprotective effect. Nevertheless, the mechanisms underlying them are largely unexplored, especially the interactions between the neuroprotection effects of vanillic acid and inflammation-immunity-metabolism. A cell metabolomics-based mathematics algorithm was reported to interpret the potential mechanism of vanillic acid on corticosterone-induced PC12 cells by regulating immune and metabolic dysregulation. Our results showed that vanillic acid markedly inhibited the level of inflammatory factors in corticosterone-induced PC12 cells. Cell metabolomics results suggested that vanillic acid regulated the abnormality of corticosterone-induced PC12 cell metabolic profiles and markedly regulated 11 differential metabolites. Our designed scoring model base entropy weight algorithm showed that the core targets (IL2RB, IFNA13, etc.) and metabolites (lactate, ethanolamine, etc.) regulate the immunity-metabolism of vanillic acid. Furthermore, we demonstrated that vanillic acid inhibited IL2RB expression and modulated the related pathway, JAK1/STAT3 signaling. The JAK inhibitor ABT-494 was further applied to validate the effect of vanillic acid on the JAK/STAT pathway. Results indicate that vanillic acid regulates the abnormal interactions of inflammation-immunity-metabolism by repressing the IL2RB-JAK1-STAT3 pathway. Methodologically, this study contributes to the decoding of vanillic acid's antidepressive effect from the metabolism perspective combined with computer algorithms and mathematics models.

Natural products: A potential immunomodulators against inflammatory-related diseases

The incidence and prevalence of inflammatory-related diseases (IRDs) are increasing worldwide. Current approved treatments for IRDs in the clinic are combat against inhibiting the pro-inflammatory cytokines. Though significant development in the treatment in the IRDs has been achieved, the severe side effects and inefficiency of currently practicing treatments are endless challenge. Drug discovery from natural sources is efficacious over a resurgence and also natural products are leading than the synthetic molecules in both clinical trials and market. The use of natural products against IRDs is a conventional therapeutic approach since it is a reservoir of unique structural chemistry, accessibility and bioactivities with reduced side effects and low toxicity. In this review, we discuss the cause of IRDs, treatment of options for IRDs and the impact and adverse effects of currently practicing clinical drugs. As well, the significant role of natural products against various IRDs, the limitations in the clinical development of natural products and thus pave the way for development of natural products as immunomodulators against IRDs are also discussed.

The Impact of Hesperidin on Cognitive Deficit and Neurobehavioural Disorders: A Systematic Review and Meta-Analysis of Preclinical Individual Studies

Purpose of Review Experimental evidence suggests that flavonoids prevent neurodegeneration and improves cognitive function. In this study, we systematically reviewed the effect of hesperidin on cognitive deficits and neurobehavioural outcomes in in vivo studies.

Recent Findings: A systematic search of PubMed, EBSCOhost, Web of Science, Scopus and ProQuest was conducted. Meta-analysis was performed on the effect of hesperidin on cognitive and neurobehavioural parameters (Morris Water Maze, Y-Maze, elevated plus maze, rotarod test, locomotion activity, passive avoidance test, open field test and forced swimming test). The mixed effect model was used to compute the standard mean difference (SMD). A total of 1069 documents were retrieved. However, 46 studies were included in the systematic review and meta-analysis. Our findings revealed that hesperidin did not significantly affect cognitive performance in normal rats compared with placebo. Moreover, hesperidin improved memory and learning, sensorimotor function and locomotion activity in cognitive impaired rats. Hesperidin did not show any significant effect on anxiety-related outcomes in the diseased model.

Summary: Hesperidin improved cognitive function and neurocognitive effects could be associated with its neuroprotective effects against neuroinflammation, oxidative stress-induced neuronal damage, inhibition of cholinergic deficit and mitochondrial dysfunction. These results correlate with available scientific evidence on the effect of hesperidin on cognitive dysfunction and neurobehavioural deficits in cognitive-impaired rats.

Jiawei Dachaihu decoction protects against mitochondrial dysfunction in atherosclerosis (AS) mice with chronic unpredictable mild stress (CUMS) via SIRT1/PGC-1α/TFAM/LON signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

JiaWei DaChaiHu is composed of Bupleurum chinense, Scutellaria baicalensis, Pinellia ternata, Paeonia lactiflora, Zingiber officinaleRoscoe, Poncirus tuifoliata, Rheum palmatum L., Curcumae Radix, Herba Lysimachiae, Ziziphus. JiaWei DaChaiHu is one of the most common traditional Chinese medicines for the treatment of depression.

AIM OF THE STUDY

The chronic unpredictable mild stress (CUMS) has been shown to promote atherosclerosis (AS). Dachaihu has been widely used in traditional Chinese medicine and has been known to exert distinct pharmacological effects. This investigation aims to examine the therapeutic effect of Jiawei Dachaihu extract on AS animal models with CUMS.

METHODS

AS-CUMS mice model was established by Apoe-/- mice. Mice were treated with Jiawei Dachaihu. Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C) levels were measured using ELISA kits. Aortic tissue pathologic changes detected by oil red O staining. Mice behavioral changes detected by sucrose preference test and sucrose preference test. The relative mRNA expression levels of CRH, ND1, and TFAM were determined by qRT-PCR. 5-HT1A, BDNF, LON, TFAM, PGC-1α, and SIRT1 protein expression determined by western blotting. ATP content detected by ATP kits.

RESULTS

The treatment with Jiawei Dachaihu extract alleviated the veins plaque and reduced stress signs in vitro and in vivo. It increased the ATP and HDL-C levels while decreased the TC, TG, LDL-C levels. Jiawei Dachaihu extract treatment upregulated Lon, SIRT1, TFAM, PGC-1α, BDNF, and 5-HT1A protein expression and regained mitochondrial function.

CONCLUSION

Jiawei Dachaihu extract could alleviate AS and reduce CUMS by upregulating the SIRT1/PGC-1α signaling and promoted its crosstalk with Lon protein to maintain mitochondrial stability.

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.

Chronic Stress-Induced Neuroinflammation: Relevance of Rodent Models to Human Disease

The brain is the central organ of adaptation to stress because it perceives and determines threats that induce behavioral, physiological, and molecular responses. In humans, chronic stress manifests as an enduring consistent feeling of pressure and being overwhelmed for an extended duration. This can result in a persistent proinflammatory response in the peripheral and central nervous system (CNS), resulting in cellular, physiological, and behavioral effects. Compounding stressors may increase the risk of chronic-stress-induced inflammation, which can yield serious health consequences, including mental health disorders. This review summarizes the current knowledge surrounding the neuroinflammatory response in rodent models of chronic stress-a relationship that is continually being defined. Many studies investigating the effects of chronic stress on neuroinflammation in rodent models have identified significant changes in inflammatory modulators, including nuclear factor-κB (NF-κB) and toll-like receptors (TLRs), and cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6. This suggests that these are key inflammatory factors in the chronic stress response, which may contribute to the establishment of anxiety and depression-like symptoms. The behavioral and neurological effects of modulating inflammatory factors through gene knockdown (KD) and knockout (KO), and conventional and alternative medicine approaches, are discussed.

Immunoregulatory role of hesperidin against ovalbumin (OVA)-induced bronchial asthma and depression in rats

Links between bronchial asthma and depression have recently become a great subject of interest. The present study was carried out to assess the protective role of hesperidin against ovalbumin (OVA)-induced bronchial asthma that is associated with depression in rats, for this purpose, four groups. Rats were sensitized with intraperitoneal administration of 200 μg OVA/10 mg aluminum hydroxide (Al (OH) 3 for 3 consecutive days then at day 11 followed by intranasal challenge with OVA (1.5 mg/kg) at days 19, 20, and 21. Rats were pretreated with hesperidin (100 & 200 mg/kg) 1h before OVA challenge. At the end of the study, behavioral tests, biochemical indices, and histopathological architectures of lung and brain tissues were evaluated. Our findings showed that hesperidin significantly ameliorated the reduction in motor activity, motor coordination, forced swimming, CD4, CD25 and foxp3, interleukin-10 (IL-10), dopamine, serotonin, and neurotrophin-3 (NT3) as well as alleviated the elevation in transforming growth factor-beta (TGF-β), tumor necrosis factor-alpha (TNF-α), iL-5, and immunoglobulin E (IgE). In addition, hesperidin reduced cellular infiltration, alveolar sacs damage, the bronchioles wall disruption, and nuclei pyknosis in neuron cells. Finally, hesperidin may provide protection against OVA-induced asthma and depression. This impact could be mediated in part by its anti-inflammatory and immunoregulatory properties.

Hesperidin reduces depressive symptoms in post-coronary artery bypass graft patients with mild depression

Previous studies have shown that hesperidin may have beneficial effects on depression; however, to the best of our knowledge, no clinical trial has yet been conducted in this area. The aim of the present study was, therefore, to determine the effects of hesperidin on depression, serum brain-derived neurotrophic factor (BDNF), and serum cortisol levels in post-coronary artery bypass graft (CABG) patients. Toward this goal, 73 post-CABG patients with depression symptoms were enrolled. The participants were randomly divided into two groups to receive either 200 mg/day hesperidin (n = 38) or placebo (n = 35) for 12 weeks. Depressive symptoms, serum BDNF, and cortisol levels were then assessed at the baseline and after intervention. Beck Depression Inventory-II (BDI-II) was also used to determine the severity of depression. Sixty-six patients completed the trial. Hesperidin decreased depression severity after 12 weeks, as compared to placebo (p = .004), but serum BDNF and cortisol were not statistically significantly different in the two groups after the intervention. Subgroup analyses also showed that, while in the patients with mild depression, the score of BDI-II was significantly different in the hesperidin and placebo groups after intervention; there was no difference in the severity of depression between the two groups in patients with moderate-to-severe depression. To conclude, a dose of 200 mg/day hesperidin may reduce depressive symptoms after 12 weeks in post-CABG patients with mild depression.

Role of BDNF-TrkB signaling in the antidepressant-like actions of loganin, the main active compound of Corni Fructus

AIMS

Corni Fructus (CF) and some CF-contained prescriptions are commonly used in clinical treatment of depression. This investigation aims to evaluate the main active compound of CF in antidepressant properties and its key target.

METHODS

Firstly, this study established a behavioral despair model and used high-performance liquid chromatography method to evaluate the antidepressant-like effects of water extract, 20%, 50%, and 80% ethanol extracts of CF, and its main active compound. Then, this study created chronic unpredictable mild stress (CUMS) model to assess loganin's antidepressant-like properties, and its target was evaluated by quantitative real-time polymerase chain reaction, Western blot, Immunofluorescence, enzyme-linked immunosorbent assay, and tyrosine receptor kinase B (TrkB) inhibitor.

RESULTS

Results showed that the different extracts of CF significantly shortened the immobility time in forced swimming and tail suspension tests. Moreover, loganin alleviated CUMS-induced depression-like behavior, promoted neurotrophy and neurogenesis, and inhibited neuroinflammation. Furthermore, K252a blocked the improvement of loganin on depression-like behavior, and eliminated the enhancement of neurotrophy and neurogenesis and the inhibition of neuroinflammation.

CONCLUSION

Overall, these results indicated that loganin could be used as a major active compound of CF for the antidepressant-like properties and exerted antidepressant-like actions by regulating brain derived neurotrophic factor (BDNF)-TrkB signaling, and TrkB could be used as key target for itsantidepressant-like actions.

Polyphenols in edible herbal medicine: targeting gut-brain interactions in depression-associated neuroinflammation

Supplementing with edible herbal medicine is an important strategy because of its role in nutrition. Many polyphenols, which are universal components in edible herbal medicines, have low bioavailability. Therefore, gut microbiota is a key determinant of polyphenol bioactivity. Polyphenols can alter the abundance of flora associated with neuroinflammation by reversing intestinal microbiota dysbiosis. Intestinal flora-mediated chemical modification of polyphenols can result in their conversion into active secondary metabolites. The current review summarizes the main edible medicines used in anti-depression and details the interactions between polyphenols and gut microbiota; in addition, it provides insights into the mechanisms underlying the possible suppression of neuroinflammation associated with depression, by polyphenols in edible herbal medicine. A better understanding of polyphenols with bioactivities that are crucial in edible herbal medicine may facilitate their use in the prevention and treatment of neuroinflammation associated with depression.

Novel bisdemethoxycurcumin@phytomicelle ophthalmic solution: In vitro formulation appraisal and in vivo prompting rapid corneal wound healing evaluations

A simple and novel phytochemical-based nano-ophthalmic solution was developed for the treatment of eye diseases. This nanoformulation was produced from the mixture of the phytochemicals glycyrrhizin and alpha-glycosyl hesperidin, which serve as the phytonanomaterials that solubilize bisdemethoxycurcumin (BDMC), a promising phytochemical with strong pharmacological activities but with poor water solubility. This novel nanoformulation is a clear solution named as BDMC@phytomicelle ophthalmic solution, which was formulated using a simple preparation process. The BDMC@phytomicelles were characterized by a BDMC encapsulation efficiency of 98.37% ± 2.26%, a small phytomicelle size of 4.06 ± 0.22 nm, and a small polydispersity index of 0.25 ± 0.04. With the optimization of the BDMC@phytomicelles, the apparent solubility of BDMC (i.e., the loading of BDMC in the phytomicelles) in the simulated lacrimal fluid was 3.19 ± 0.02 mg/ml. The BDMC@phytomicelle ophthalmic solution demonstrated a good storage stability. Moreover, it did not cause irritations in rabbit eyes, and it facilitated the excellent corneal permeation of BDMC in mice. The BDMC@phytomicelles demonstrated a marked effect on the in vivo induction of corneal wound healing both in healthy and denervated corneas, as seen in the induction of corneal epithelial wound healing, recovery of corneal sensitivity, and increase in corneal subbasal nerve fiber density. These strong pharmacological activities involve the inhibition of hmgb1 signaling and the induction of VIP signaling. Overall, the BDMC@phytomicelle ophthalmic solution is a novel and promising simple ocular nano-formulation of BDMC with significantly improved in vivo profiles.

Serum levels of high mobility group box-1 protein (HMGB1) and soluble receptors of advanced glycation end-products (RAGE) in depressed patients treated with electroconvulsive therapy

AIMS

High mobility group box-1 (HMGB1) is one of the damage-associated molecular patterns produced by stress and induces inflammatory responses mediated by receptors of advanced glycation end-products (RAGE) on the cell surface. Meanwhile, soluble RAGE (sRAGE) exhibits an anti-inflammatory effect by capturing HMGB1. Animal models have shown upregulation of HMGB1 and RAGE in the brain or blood, suggesting the involvement of these proteins in depression pathophysiology. However, there have been no reports using blood from depressed patients, nor ones focusing on HMGB1 and sRAGE changes associated with treatment and their relationship to depressive symptoms.

METHODS

Serum HMGB1 and sRAGE concentrations were measured by enzyme-linked immunosorbent assay in a group of patients with severe major depressive disorder (MDD) (11 males and 14 females) who required treatment with electroconvulsive therapy (ECT), and also in a group of 25 age- and gender-matched healthy subjects. HMGB1 and sRAGE concentrations were also measured before and after a course of ECT. Depressive symptoms were assessed using the Hamilton Rating Scale for Depression (HAMD).

RESULTS

There was no significant difference in HMGB1 and sRAGE concentrations in the MDD group compared to healthy subjects. Although ECT significantly improved depressive symptoms, there was no significant change in HMGB1 and sRAGE concentrations before and after treatment. There was also no significant correlation between HMGB1 and sRAGE concentrations and the HAMD total score or subitem scores.

CONCLUSION

There were no changes in HMGB1 and sRAGE in the peripheral blood of severely depressed patients, and concentrations had no relationship with symptoms or ECT.

Glucosyl hesperidin exhibits more potent anxiolytic activity than hesperidin accompanied by the attenuation of noradrenaline induction in a zebrafish model

Anxiety is a symptom of various mental disorders, including depression. Severe anxiety can significantly affect the quality of life. Hesperidin (Hes), a flavonoid found in the peel of citrus fruits, reportedly has various functional properties, one of which is its ability to relieve acute and chronic stress. However, Hes is insoluble in water, resulting in a low absorption rate in the body and low bioavailability. Glucosyl hesperidin (GHes) is produced by adding one glucose molecule to hesperidin. Its water solubility is significantly higher than that of Hes, which is expected to improve its absorption into the body and enhance its effects. However, its efficacy in alleviating anxiety has not yet been investigated. Therefore, in this study, the anxiolytic effects of GHes were examined in a zebrafish model of anxiety. Long-term administration of diets supplemented with GHes did not cause any toxicity in the zebrafish. In the novel tank test, zebrafish in the control condition exhibited an anxious behavior called freezing, which was significantly suppressed in GHes-fed zebrafish. In the black-white preference test, which also induces visual stress, GHes-fed zebrafish showed significantly increased swimming time in the white side area. Furthermore, in tactile (low water-level stress) and olfactory-mediated stress (alarm substance administration test) tests, GHes suppressed anxious behavior, and these effects were stronger than those of Hes. Increased noradrenaline levels in the brain generally cause freezing; however, in zebrafish treated with GHes, the amount of noradrenaline after stress was lower than that in the control group. Activation of c-fos/ERK/Th, which is upstream of the noradrenaline synthesis pathway, was also suppressed, while activation of the CREB/BDNF system, which is vital for neuroprotective effects, was significantly increased. These results indicate that GHes has a more potent anxiolytic effect than Hes in vivo, which may have potential applications in drug discovery and functional food development.

HMGB1 in depression: An overview of microglial HMBG1 in the pathogenesis of depression

Depression is a prevalent psychiatric disorder with elusive pathogenesis. Studies have proposed that enhancement and persistence of aseptic inflammation in the central nervous system (CNS) may be closely associated with the development of depressive disorder. High mobility group box 1 (HMGB1) has obtained significant attention as an evoking and regulating factor in various inflammation-related diseases. It is a non-histone DNA-binding protein that can be released as a pro-inflammatory cytokine by glial cells and neurons in the CNS. Microglia, as the immune cell of the brain, interacts with HMGB1 and induces neuroinflammation and neurodegeneration in the CNS. Therefore, in the current review, we aim to investigate the role of microglial HMGB1 in the pathogenetic process of depression.

Polyphenols as novel interventions for depression: exploring the efficacy, mechanisms of action, and implications for future research

Numerous animal and human studies have assessed the relationship between polyphenols and outcomes related to depression. However, no comprehensive synthesis of the main findings has been conducted. The aim of this manuscript was to systematically review the available evidence from animal and human studies on the association and the effects of dietary polyphenols on depression and provide recommendations for future research. We based our review on 163 preclinical animal, 16 observational and 44 intervention articles assessing the relationship between polyphenols and outcomes related to depression. Most animal studies demonstrated that exposure to polyphenols alleviated behaviours reported to be associated with depression. However, human studies are less clear, with some studies reporting and inverse relationship between the intake of some polyphenols, and polyphenol rich foods and depression risk and symptoms, while others reporting no association or effect. Hence, while there has been extensive research conducted in animals and there is some supporting evidence in humans, further human studies are required, particularly in younger and clinical populations.

Prophylactic effect of Tongxieyaofang polysaccharide on depressive behavior in adolescent male mice with chronic unpredictable stress through the microbiome-gut-brain axis

Major depression disorder is more common among adolescents and is a primary reason for suicide in adolescents. Some antidepressants are ineffective and may possess side effects. Therefore, developing an adolescent antidepressant is the need of the hour. We designed the stress model of adolescent male mice induced by chronic unpredictable stress (CUS). The mice were treated using Tongxieyaofang neutral polysaccharide (TXYF-NP), Tongxieyaofang acidic polysaccharide (TXYF-AP), TXYF-AP + TXYF-NP and fructooligosaccharide + galactooligosaccharides to determine their body weight, behavior, and serum hormone levels. RT-qPCR was used to detect the gene expression of Crhr1, Nr3c1, and Nr3c2 in the hypothalamus and hippocampus and the gene expression of glutamic acid and γ-aminobutyric acid-related receptors in the hippocampus. RT-qPCR, Western blot, and ELISA detected tryptophan metabolism in the colon, serum, and hippocampus. 16s rDNA helped sequence colon microflora, and non-targeted metabolomics enabled the collection of metabolic profiles of colon microflora. In adolescent male mice, CUS induced depression-like behavior, hypothalamic-pituitary-adrenal axis hyperactivity, hippocampal tissue damage, abnormal expression of its related receptors, and dysregulation of tryptophan metabolism. The 16s rDNA and non-targeted metabolomics revealed that CUS led to colon microflora disorder and bile acid metabolism abnormality. Tongxieyaofang polysaccharide could improve the bacterial community and bile acid metabolism disorder by upregulating the relative abundance of Lactobacillus gasseri, Lachnospiraceae bacterium 28-4, Bacteroides and Ruminococcaceae UCG-014 while preventing CUS-induced changes. TXYF-P can inhibit depression-like behavior due to CUS by regulating colonic microflora and restoring bile acid metabolism disorder. Thus, based on the different comparisons, TXYF-NP possessed the best effect.

Exploring the multifocal role of phytoconstituents as antidepressants

Depression is the most prevalent and devastating neuropsychiatric disorder. There are several conventional antidepressants used for the treatment of depression. But due to their undesired adverse effects, patient compliance is very poor. Thus, developing novel medications for the treatment of depression is a critical strategic priority for meeting therapeutic demands. Current research is looking for alternatives to traditional antidepressants to reduce undesired side effects and increase efficacy. Phytoconstituents provide a wide research range in antidepressant treatments. In the present article, we have conducted a comprehensive assessment of neurological evidence, which supports the usefulness of phytoconstituents in the treatment of the depressive disorder. Secondary plant metabolites including alkaloids, polyphenols, glycosides, saponins, and terpenoids were found to exhibit antidepressant action. Most of the phytoconstituents were found to mediate their antidepressant effect through the upregulation of brain-derived neurotrophic factor (BDNF), serotonin, noradrenaline, and dopamine. Some were also found to exert antidepressant effects by inhibiting the monoamine oxidase (MAO) activity and hypothalamic-pituitary-adrenal (HPA) axis overactivity.

Bullatine A has an antidepressant effect in chronic social defeat stress mice; Implication of microglial inflammasome

Inflammatory microglia and P2X7R are involved in the development of stress-induced depression. Endoplasmic reticulum (ER) stress and mitochondrial damage play an important role in depression and microglial activation. Bullatine A (BLA) has anti-inflammatory and anti-rheumatic effects, and can be used as a P2X7R antagonist. We found that Bullatine A can effectively inhibit the calcium overload of mitochondria and the increase of ER and mitochondrial colocalization caused by eATP (extracellular ATP) in BV2-cells. Bullatine A can also inhibit the activation of PERK-elF-2α unfolded protein response (UPR), lysosome production and the increase of NLRP3 inflammasome protein expression in BV2-cells Both intragastric administration and intra-hippocampal microinjection of Bullatine A can significantly improve the despair behavior but not anhedonia of Chronic chronic social defeat stress (CSDS) mice. Bullatine A may have a beneficial therapeutic effect in treating diseases related to stress stimulation, such as depression.

Phytochemicals That Act on Synaptic Plasticity as Potential Prophylaxis against Stress-Induced Depressive Disorder

Depression is a neuropsychiatric disorder associated with persistent stress and disruption of neuronal function. Persistent stress causes neuronal atrophy, including loss of synapses and reduced size of the hippocampus and prefrontal cortex. These alterations are associated with neural dysfunction, including mood disturbances, cognitive impairment, and behavioral changes. Synaptic plasticity is the fundamental function of neural networks in response to various stimuli and acts by reorganizing neuronal structure, function, and connections from the molecular to the behavioral level. In this review, we describe the alterations in synaptic plasticity as underlying pathological mechanisms for depression in animal models and humans. We further elaborate on the significance of phytochemicals as bioactive agents that can positively modulate stress-induced, aberrant synaptic activity. Bioactive agents, including flavonoids, terpenes, saponins, and lignans, have been reported to upregulate brain-derived neurotrophic factor expression and release, suppress neuronal loss, and activate the relevant signaling pathways, including TrkB, ERK, Akt, and mTOR pathways, resulting in increased spine maturation and synaptic numbers in the neuronal cells and in the brains of stressed animals. In clinical trials, phytochemical usage is regarded as safe and well-tolerated for suppressing stress-related parameters in patients with depression. Thus, intake of phytochemicals with safe and active effects on synaptic plasticity may be a strategy for preventing neuronal damage and alleviating depression in a stressful life.

The benefits of hesperidin in central nervous system disorders, based on the neuroprotective effect

Disorders of central nervous system (CNS) disorders are considered serious health issues. The most common CNS diseases include neurodegenerative diseases, mental disorders, demyelinating disease, ischemia-reperfusion injury, and neuroinflammation. As a natural phenolic compound, hesperidin is a flavanone glycoside with various biological effects. Increasing evidence show that the growth of CNS diseases is hindered by hesperidin. Here, we have reviewed the related literature on neuropharmacological mechanisms for the preventive and therapeutic effects of hesperidin on CNS diseases. Several cellular and animal models have been developed to evaluate the underlying neuropharmacological mechanisms of hesperidin. Additionally, clinical evidence has confirmed its neuroprotective function. Hesperidin exerts its neuroprotective properties by decreasing neuro-inflammatory and apoptotic pathways. Hesperidin function has been studied in preclinical models for CNS diseases, but little is known about its definite effect in humans. Hesperidin can effectively alleviate depression and improve cognition and memory. It is urgent to explore and discover clinical trials for further confirmation of the neuroprotective efficacy of hesperidin and to evaluate its safety profile.

Neuroprotective Potentials of Flavonoids: Experimental Studies and Mechanisms of Action

Neurological and neurodegenerative diseases, particularly those related to aging, are on the rise, but drug therapies are rarely curative. Functional disorders and the organic degeneration of nervous tissue often have complex causes, in which phenomena of oxidative stress, inflammation and cytotoxicity are intertwined. For these reasons, the search for natural substances that can slow down or counteract these pathologies has increased rapidly over the last two decades. In this paper, studies on the neuroprotective effects of flavonoids (especially the two most widely used, hesperidin and quercetin) on animal models of depression, neurotoxicity, Alzheimer's disease (AD) and Parkinson's disease are reviewed. The literature on these topics amounts to a few hundred publications on in vitro and in vivo models (notably in rodents) and provides us with a very detailed picture of the action mechanisms and targets of these substances. These include the decrease in enzymes that produce reactive oxygen and ferroptosis, the inhibition of mono-amine oxidases, the stimulation of the Nrf2/ARE system, the induction of brain-derived neurotrophic factor production and, in the case of AD, the prevention of amyloid-beta aggregation. The inhibition of neuroinflammatory processes has been documented as a decrease in cytokine formation (mainly TNF-alpha and IL-1beta) by microglia and astrocytes, by modulating a number of regulatory proteins such as Nf-kB and NLRP3/inflammasome. Although clinical trials on humans are still scarce, preclinical studies allow us to consider hesperidin, quercetin, and other flavonoids as very interesting and safe dietary molecules to be further investigated as complementary treatments in order to prevent neurodegenerative diseases or to moderate their deleterious effects.

Hepatoprotective and cognitive-enhancing effects of hesperidin against thioacetamide-induced hepatic encephalopathy in rats

Hepatic encephalopathy (HE) is a serious neurological disorder which might occur in both acute and chronic liver injury.

AIMS

This study was carried out to explore the protective effects of hesperidin against experimentally induced HE.

MAIN METHODS

Rats were sorted into four groups each of six; Normal group, TAA group: rats were administered 350 mg/kg of TAA i.p. from day 5 to day 7. TAA+ Hesp 100 group: rats were administered hesperidin 100 mg/kg/day orally for 7 days along with i.p TAA injection 350 mg/kg from day 5 to 7. TAA+ Hesp 200 group: rats were administered hesperidin 200 mg/kg/day orally for 7 days along with i.p TAA injection 350 mg/kg from day 5 to 7. Liver function, oxidative stress biomarkers, behavioral tests in addition to histopathological examination were assessed.

KEY FINDINGS

Hesperidin efficiently mitigated TAA-induced HE as evidenced by significant reduction in liver enzymes, bile and ammonia levels in serum. Moreover, hesperidin restored oxidant/antioxidant balance as manifested by reduction in MDA content in both cerebral and hepatic tissues. Additionally, hesperidin improved motor and cognitive abilities besides tissues' architecture as demonstrated by behavioral tests and histopathology results, respectively. Hesperidin also decreased levels of NLRP3 and increased levels of Sirt1 and FOXO in both cerebral and hepatic tissues. Finally, hesperidin markedly decreased the expression of IL-1β and caspase-1 as shown by immunohistochemical results.

SIGNIFICANCE

Taken together, the hepatoprotective impact of hesperidin and its ameliorative effect on the progression of HE appear to be mediated by its modulatory influence on NLRP3/Sirt1/FOXO signaling.

Antidepressive Effect of Natural Products and Their Derivatives Targeting BDNF-TrkB in Gut-Brain Axis

Modern neurological approaches enable detailed studies on the pathophysiology and treatment of depression. An imbalance in the microbiota-gut-brain axis contributes to the pathogenesis of depression. This extensive review aimed to elucidate the antidepressive effects of brain-derived neurotrophic factor (BDNF)-targeting therapeutic natural products and their derivatives on the gut-brain axis. This information could facilitate the development of novel antidepressant drugs. BDNF is crucial for neuronal genesis, growth, differentiation, survival, plasticity, and synaptic transmission. Signaling via BDNF and its receptor tropomyosin receptor kinase B (TrkB) plays a vital role in the etiopathogenesis of depression and the therapeutic mechanism of antidepressants. This comprehensive review provides information to researchers and scientists for the identification of novel therapeutic approaches for neuropsychiatric disorders, especially depression and stress. Future research should aim to determine the possible causative role of BDNF-TrkB in the gut-brain axis in depression, which will require further animal and clinical research as well as the development of analytical approaches.

Neurological disorders of COVID-19: insights to applications of natural products from plants and microorganisms

In addition to the typical respiratory manifestations, various disorders including involvement of the nerve system have been detected in COVID-19 ranging from 22 to 36%. Although growing records are focusing on neurological aspects of COVID-19, the pathophysiological mechanisms and related therapeutic methods remain obscure. Considering the increased concerns of SARS-CoV-2 potential for more serious neuroinvasion conditions, the present review attempts to focus on the neuroprotective effects of natural compounds as the principle source of therapeutics inhibiting multiple steps of the SARS-CoV-2 infection cycle. The great majority of the natural products with anti-SARS-CoV-2 activity mainly inhibit the attachment, entry and gene expression rather than the replication, assembly, or release. Although microbial-derived natural products comprise 38.5% of the known natural products with neuroprotective effects following viral infection, the neuroprotective potential of the majority of microorganisms is still undiscovered. Among natural products, chrysin, huperzine A, ginsenoside Rg1, pterostilbene, and terrein have shown potent in vitro neuroprotective activity and can be promising for new or repurpose drugs for neurological complications of SARS-CoV-2.

Mixture of Tomato and Lemon Extracts Synergistically Prevents PC12 Cell Death from Oxidative Stress and Improves Hippocampal Neurogenesis in Aged Mice

Dietary habits have a great impact on one's health, especially in cognitive decline. Tomato and lemon contain diverse bioactive compounds and possess various effects, including the enhancement of cognitive function. We observed the protective effect of tomato, lemon extract and the mixture of them on H2O2-induced cytotoxicity of PC12 cells. To measure the in vivo effect in a murine model, each extract was orally administered to forty 1-year-old mice for 6 weeks, and a novel object recognition (NOR) test was performed to observe cognitive function, and hippocampal neurogenesis was observed through a doublecortin (DCX) stain. PC12 cell death by oxidative stress was reduced by pretreating with each extract, and a synergistic reduction was observed in the mixture. Newly generated DCX-positive neurons were synergistically increased in the hippocampus by the mixture. NOR test showed a tendency to significantly improve age-related cognitive dysfunction by consuming the mixture of tomato and lemon. In conclusion, tomato and lemon extracts can reduce cellular oxidative stress and increase NOR, likely due to enhanced neurogenesis, while the mixture of the two showed synergistic anti-oxidative effects and hippocampal neurogenesis.

Beneficial effects of natural flavonoids on neuroinflammation

Neuroinflammation is the fundamental immune response against multiple factors in the central nervous system and is characterized by the production of inflammatory mediators, activated microglia and astrocytes, and the recruitment of innate and adaptive immune cells to inflammatory sites, that contributes to the pathological process of related brain diseases, such as Alzheimer’s disease, Parkinson’s disease, depression, and stroke. Flavonoids, as a species of important natural compounds, have been widely revealed to alleviate neuroinflammation by inhibiting the production of pro-inflammatory mediators, elevating the secretion of anti-inflammatory factors, and modulating the polarization of microglia and astrocyte, mainly via suppressing the activation of NLRP3 inflammasome, as well as NF-κB, MAPK, and JAK/STAT pathways, promoting Nrf2, AMPK, BDNF/CREB, Wnt/β-Catenin, PI3k/Akt signals and SIRT1-mediated HMGB1 deacetylation. This review will provide the latest and comprehensive knowledge on the therapeutic benefits and mechanisms of natural flavonoids in neuroinflammation, and the natural flavonoids might be developed into food supplements or lead compounds for neuroinflammation-associated brain disorders.

Effect of Sopoongsan on Skin Inflammation and Hyperlocomotion in Socially Isolated Mice with Atopic Dermatitis

Psychological stress is a major exacerbating factor of atopic dermatitis (AD), a chronic inflammatory skin disease. Sopoongsan (SPS), a traditional herbal formula, has been indicated for the treatment of various skin disorders, including AD. This study investigated the effects of SPS on a 2,4-dinitrochlorobenzene- (DNCB-) induced AD mice model exposed to social isolation (SI) stress. The severity of the AD symptoms and behavioral abnormalities was evaluated. SPS reduced the clinical skin score as evaluated with the SCORing Atopic Dermatitis (SCORAD) index and suppressed the cutaneous infiltration of T-lymphocyte cells, mast cells, and eosinophils in SI-AD mice. The SPS treatment decreased the total distance and mean speed and increased resting time in the open field test (OFT) for these mice. In addition, the time spent in the social zone in the social interaction test also improved when SPS treatment was given. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in the prefrontal cortex (PFC) in the SI-AD mice were reduced by the oral administration of SPS. HaCaT and BV2 cells were used for the in vitro experiments. The pretreatment with SPS reduced the protein levels of the thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) in the HaCaT cells stimulated with TNF-α and interferon-gamma (IFN-γ) (TI). SPS also suppressed TNF-α and IL-6 secretion in lipopolysaccharide- (LPS-) stimulated BV2 cells. These results imply that SPS could be a promising candidate for the treatment of AD in patients under stress conditions and at risk of exacerbation.

Potential Psychoactive Effects of Microalgal Bioactive Compounds for the Case of Sleep and Mood Regulation: Opportunities and Challenges

Sleep deficiency is now considered an emerging global epidemic associated with many serious health problems, and a major cause of financial and social burdens. Sleep and mental health are closely connected, further exacerbating the negative impact of sleep deficiency on overall health and well-being. A major drawback of conventional treatments is the wide range of undesirable side-effects typically associated with benzodiazepines and antidepressants, which can be more debilitating than the initial disorder. It is therefore valuable to explore the efficiency of other remedies for complementarity and synergism with existing conventional treatments, leading to possible reduction in undesirable side-effects. This review explores the relevance of microalgae bioactives as a sustainable source of valuable phytochemicals that can contribute positively to mood and sleep disorders. Microalgae species producing these compounds are also catalogued, thus creating a useful reference of the state of the art for further exploration of this proposed approach. While we highlight possibilities awaiting investigation, we also identify the associated issues, including minimum dose for therapeutic effect, bioavailability, possible interactions with conventional treatments and the ability to cross the blood brain barrier. We conclude that physical and biological functionalization of microalgae bioactives can have potential in overcoming some of these challenges.

Multi-strain Probiotic Formulation Reverses Maternal Separation and Chronic Unpredictable Mild Stress-Generated Anxiety- and Depression-like Phenotypes by Modulating Gut Microbiome-Brain Activity in Rats

Depression is a debilitating mental disorder that affects >322 million people worldwide. Despite the availability of several antidepressant agents, many patients remain treatment refractory. A growing literature study has indicated the role of gut microbiota in neuropsychiatric disorders. Herein, we examined the psychobiotic-like activity of multi-strain probiotic formulation in maternal separation (MS) and chronic unpredictable mild stress (CUMS) models of anxiety- and depression-like phenotypes in Sprague-Dawley rats. Early- and late-life stress was employed in both male and female rats by exposing them to MS and CUMS. The multi-strain probiotic formulation (Cognisol) containing Bacillus coagulans Unique IS-2, Lactobacillus plantarum UBLP-40, Lactobacillus rhamnosus UBLR-58, Bifidobacterium lactis UBBLa-70, Bifidobacterium breve UBBr-01, and Bifidobacterium infantis UBBI-01 at a total strength of 10 billion cfu along with l-glutamine was administered for 6 weeks via drinking water. Neurobehavioral assessment was done using the forced swim test (FST), sucrose preference test (SPT), elevated plus maze (EPM), and open field test (OFT). Animals were sacrificed after behavioral assessment, and blood, brain, and intestine samples were collected to analyze the levels of cytokines, metabolites, and neurotransmitters and histology. Animals exposed to stress showed increased passivity, consumed less sucrose solution, and minimally explored the open arms in the FST, SPT, and EPM, respectively. Administration of multi-strain probiotics along with l-glutamine for 6 weeks ameliorated the behavioral abnormalities. The locomotor activity of animals in the OFT and their body weight remained unchanged across the groups. Cognisol treatment reversed the decreased BDNF and serotonin levels and increased CRP, TNF-α, and dopamine levels in the hippocampus and/or frontal cortex. Administration of Cognisol also restored the plasma levels of l-tryptophan, l-kynurenine, kynurenic-acid, and 3-hydroxyanthranilic acid; the Firmicutes-to-Bacteroides ratio; the levels of acetate, propionate, and butyrate in fecal samples; the villi/crypt ratio; and the goblet cell count, which manifested in the restoration of intestinal functions. We suggest that the multi-strain probiotic and glutamine formulation (Cognisol) ameliorated the MS + UCMS-generated anxiety- and depression-like phenotypes by reshaping the gut microbiome-brain activity in both sexes.

Role of high mobility group box protein 1 in depression: A mechanistic and therapeutic perspective

As a common and serious psychiatric disorder, depression significantly affects psychosocial functioning and quality of life. However, the mechanism of depression is still enigmatic and perplexing, which limits its precise and effective therapeutic methods. Recent studies demonstrated that neuroinflammation activation plays an important role in the pathophysiology of depression. In this respect, high mobility group box 1 (HMGB1) may be a possible signaling inducer of neuroinflammation and can be a potential mechanistic and therapeutic target for depression. Herein, we review recent studies on the mechanistic and therapeutic targets of HMGB1 in depression and propose potential perspectives on this topic.

Inhibition of Connexin 36 attenuates HMGB1-mediated depressive-like behaviors induced by chronic unpredictable mild stress

BACKGROUND

High mobility group box 1 (HMGB1) released by neurons and microglia was demonstrated to be an important mediator in depressive-like behaviors induced by chronic unpredictable mild stress (CUMS), which could lead to the imbalance of two different metabolic approaches in kynurenine pathway (KP), thus enhancing glutamate transmission and exacerbating depressive-like behaviors. Evidence showed that HMGB1 signaling might be regulated by Connexin (Cx) 36 in inflammatory diseases of central nervous system (CNS). Our study aimed to further explore the role of Cx36 in depressive-like behaviors and its relationship with HMGB1.

METHODS

After 4-week chronic stress, behavioral tests were conducted to evaluate depressive-like behaviors, including sucrose preference test (SPT), tail suspension test (TST), forced swimming test (FST), and open field test (OFT). Western blot analysis and immunofluorescence staining were used to observe the expression and location of Cx36. Enzyme-linked immunosorbent assay (ELISA) was adopted to detect the concentrations of inflammatory cytokines. And the excitability and inward currents of hippocampal neurons were recorded by whole-cell patch clamping.

RESULTS

The expression of Cx36 was significantly increased in hippocampal neurons of mice exposed to CUMS, while treatment with glycyrrhizinic acid (GZA) or quinine could both down-regulate Cx36 and alleviate depressive-like behaviors. The proinflammatory cytokines like HMGB1, tumor necrosis factor alpha (TNF-α), and interleukin-1β (IL-1β) were all elevated by CUMS, and application of GZA and quinine could decrease them. In addition, the enhanced excitability and inward currents of hippocampal neurons induced by lipopolysaccharide (LPS) could be reduced by either GZA or quinine.

CONCLUSIONS

Inhibition of Cx36 in hippocampal neurons might attenuates HMGB1-mediated depressive-like behaviors induced by CUMS through down-regulation of the proinflammatory cytokines and reduction of the excitability and intracellular ion overload.

Neuroinflammation and Mitochondrial Dysfunction Link Social Stress to Depression

Major depressive disorder is a debilitating mental illness and a leading cause of global disease burden. While many etiological factors have been identified, social stress is a highly prevalent causative factor for the onset of depression. Unfortunately, rates of depression continue to increase around the world, and the recent COVID-19 pandemic has further exacerbated this mental health crisis. Though several therapeutic strategies are available, nearly 50% of patients who receive treatment never reach remission. The exact mechanisms by which social stress exposure promotes the development of depression are unclear, making it challenging to develop novel and more effective therapeutics. However, accumulating evidence points to a role for stress-induced neuroinflammation, particularly in treatment-resistant patients. Moreover, recent evidence has expanded the concept of the pathogenesis of depression to mitochondrial dysfunction, suggesting that the combined effects of social stress on mitochondria and inflammation may synergize to facilitate stress-related depression. In this chapter, we review evidence for neuroinflammation and mitochondrial dysfunction in the pathogenesis of social stress-induced depression and discuss these in the context of novel therapeutic targets for the treatment of depression.

Saxagliptin ameliorated the depressive-like behavior induced by chronic unpredictable mild stress in rats: Impact on incretins and AKT/PI3K pathway

Depression is a widespread, withering illness, resulting in a massive personal suffering and economic loss. The chronic exposure to stress may be involved in the etiology of human psychiatric disorders; such as depression. In the current study, the animals were subjected to chronic unpredictable mild stress (CUMS) for 14 days. Saxagliptin (SAXA) is a member of dipeptidyl peptidase-4 (DPP-4) inhibitors class. The current study was the first one to examine the anti-depressive effect of SAXA in an experimental model of CUMS-induced depression in rats and the possible underlying mechanisms. Animals were orally treated with SAXA (0.5, 1 and 2 mg/kg) for 14 days. SAXA treatment reversed the CUMS-induced alterations in the behavioral, biochemical as well as histopathological parameters. Moreover, it hindered the CUMS-induced increase in the oxidative stress, inflammatory, and apoptotic markers. On the other hand, it increased the monoamines levels and the neurogenic brain derived neurotrophic factor (BDNF). In addition, SAXA treatment increased the incretin hormones, glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), which are linked to the activation of protein kinase B (AKT)/phosphatidylinositol3-kinase (PI3K) pathway. In conclusion, the current study revealed that the modulation of the interplay between the key events involved in depression, including oxidative stress, inflammation, and GLP-1/PI3K/AKT signaling pathway, can explain the anti-depressant activity of SAXA.

Cerebrospinal fluid proteomics reveal potential protein targets of JiaWeiSiNiSan in preventing chronic psychological stress damage

CONTEXT

Chinese herbal formula JiaWeiSiNiSan (JWSNS) has been widely used to prevent stress-induced neuropsychiatric ailments in clinics and proven to have therapeutic anti-stress effects on rats. However, the mechanism remains unclear.

OBJECTIVE

Based on the proteomics of cerebrospinal fluid (CSF), this study explores the possible mechanism and target proteins of JiaWeiSiNiSan raising stress resilience and preventing stress damage.

MATERIALS AND METHODS

A 6-week Chronic Unpredictable Mild Stress (CUMS) model was applied on adult Wistar male rats to observe the effects of JWSNS on improving mental stress resilience. Tandem Mass Tag (TMT) proteomics and bioinformatics analysis were used to screen and analyze differentially expressed proteins (DEPs) in CSF. Parallel Reaction Monitoring (PRM) was used to validate target DEPs.

RESULTS

Significantly decreased sucrose preference, locomotion activity level and accuracy of T-maze, as well as increased immobility time, were observed in CUMS rats compared to CON rats while JWSNS improved above depression-like behaviours. The quantitative proteomics and bioinformatics analysis showed that JWSNS decreased the expression of Rps4x, HSP90AA1, Rps12, Uba1, Rsp14, Tuba1b in CUMS rats CSF (p < 0.05, FDR < 0.5). Immunofluorescence results showed that the number of BrdU/DCX positive cells (p < 0.01) and the relative number of neurons (p < 0.01) in the hippocampus dentate gyrus (DG) of the JSWNS group significantly increased, compared with the CUMS group.

CONCLUSIONS

JWSNS could increase mental stress resilience and prevent stress damage by regulating proteins in CSF. This study provides a scientific basis for further study on Chinese formulas preventing mental illness.

Theacrine, a Potent Antidepressant Purine Alkaloid from a Special Chinese Tea, Promotes Adult Hippocampal Neurogenesis in Stressed Mice

Daily intake of tea has been known to relate to a low risk of depression. In this study, we report that a special variety of tea in China, Camellia assamica var. kucha (kucha), possesses antidepressant effects but with less adverse effects as compared to traditional tea Camellia sinensis. This action of kucha is related to its high amount of theacrine, a purine alkaloid structurally similar to caffeine. We investigated the antidepressant-like effects and mechanisms of theacrine in chronic water immersion restraint stress and chronic unpredictable mild stress mice models. PC12 cells and primary hippocampal neural stem cells were treated with stress hormone corticosterone (CORT) to reveal the potential antidepression mechanism of theacrine from the perspective of adult hippocampus neurogenesis. Results of behavioral and neurotransmitter analysis showed that intragastric administration of theacrine significantly counteracted chronic stress-induced depression-like disorders and abnormal 5-hydroxytryptamine (5-HT) metabolism with less central excitability. Further investigation from both in vivo and in vitro experiments indicated that the antidepressant mechanism of theacrine was associated with promoting adult hippocampal neurogenesis, via the modulation of the phosphodiesterase-4 (PDE4)/cyclic adenosine monophosphate (cAMP)/cAMP response-element binding (CREB)/brain-derived neurotrophic factor (BDNF)/tropomyosin-related kinase B (TrkB) pathway. Collectively, our findings could promote the prevalence of kucha as a common beverage with uses for health care and contribute to the development of theacrine as a potential novel antidepressant medicine.

Expression of ghrelin or growth hormone secretagogue receptor in the brain of postpartum stress mice

Postpartum depression is one of the most common mental diseases that occur in women after childbirth; this disorder is extremely painful for women and represents a major burden on the society. Therefore, we designed this study to explore the possible material basis of the disease, and provide potential novel antidepressants therapy using a mouse model. We established a postpartum immobilization stress model. Maternal body weight changes and food intake were recorded for half a month after delivery, and levels of ghrelin and its receptor, growth hormone secretagogue receptor (GHSR) were measured. The mice in the immobilization stress group showed stress activity as well as low body weight and low feeding status. Ghrelin expression was elevated in blood whereas ghrelin or GHSR expression decreased in the hippocampus and prefrontal cortex of the immobilization stress mice, and the number of ghrelin-active and GHSR cells reduced.

Fecal microbiota transplantation ameliorates stress-induced depression-like behaviors associated with the inhibition of glial and NLRP3 inflammasome in rat brain

BACKGROUND

Evidence from previous studies has demonstrated that the gut-microbiota-brain axis is vital in regulating of behavior and neuroinflammation in the central nervous system. Considering the putative connection among gut microbiota, neural function, and behavior, the present study investigated the potential signaling of gut microbiota to modulate depression-like behaviors and neuroinflammation.

METHODS

Rats showing depression-like behaviors induced by chronic unpredictable mild stress received fecal microbiota treatment or vehicle for 14 days, and alterations in behavior and neuroinflammation were assessed. ELISA, immunofluorescence staining and Western blot were used to analysis the activation of glial cells and NLRP3 inflammasome.

RESULTS

Treatment with fecal microbiota transplantation ameliorated depression-like behaviors. 5-Hydroxytryptamine decreased in the chronic unpredictable mild stress rat model but significantly increased after fecal microbiota transplantation. The treatment with fecal microbiota transplantation decreased the production of IL-1β and TNF-α. Moreover, fecal microbiota transplantation administration suppressed the activation of Iba1 positive microglia cells and GFAP positive astrocytes cells and reduced the expression of NLRP3, ASC, Caspase-1, and IL-1β pathway in the prefrontal cortex and hippocampus.

CONCLUSIONS

Fecal microbiota transplantation can improve depression-like behaviors induced by chronic unpredictable mild stress. The anti-depression effects of fecal microbiota transplantation were associated with the suppressed activation of glial cells and NLRP3 inflammasome in the brain.

Global survey of medicinal plants during lactation and postpartum recovery: Evolutionary perspectives and contemporary health implications

ETHNOPHARMACOLOGICAL RELEVANCE

Cross-cultural comparison of plants used during lactation and the postpartum period offers insight into a largely overlooked area of ethnopharmacological research. Potential roles of phytochemicals in emerging models of interaction among immunity, inflammation, microbiome and nervous system effects on perinatal development have relevance for the life-long health of individuals and of populations in both traditional and contemporary contexts.

AIM OF THE STUDY

Delineate and interpret patterns of traditional and contemporary global use of medicinal plants ingested by mothers during the postpartum period relative to phytochemical activity on immune development and gastrointestinal microbiome of breastfed infants, and on maternal health.

MATERIALS AND METHODS

Published reviews and surveys on galactagogues and postpartum recovery practices plus ethnobotanical studies from around the world were used to identify and rank plants, and ascertain regional use patterns. Scientific literature for 20 most-cited plants based on frequency of publication was assessed for antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, antidepressant, analgesic, galactagogic and safety properties.

RESULTS

From compilation of 4418 use reports related to 1948 species, 105 plant taxa were recorded ≥7 times, with the most frequently cited species, Foeniculum vulgare, Trigonella foenum-graecum, Pimpinella anisum, Euphorbia hirta and Asparagus racemosus, 81, 64, 42, 40 and 38 times, respectively. Species and use vary globally, illustrated by the pattern of aromatic plants of culinary importance versus latex-producing plants utilized in North Africa/Middle East and Sub-Saharan Africa with opposing predominance. For 18/20 of the plants a risk/benefit perspective supports assessment that positive immunomodulation and related potential exceed any safety concerns. Published evidence does not support a lactation-enhancing effect for nearly all the most-cited plants while antidepressant data for the majority of plants are predominately limited to animal studies.

CONCLUSIONS

Within a biocultural context traditional postpartum plant use serves adaptive functions for the mother-infant dyad and contributes phytochemicals absent in most contemporary diets and patterns of ingestion, with potential impacts on allergic, inflammatory and other conditions. Polyphenolics and other phytochemicals are widely immunologically active, present in breast milk and predominately non-toxic. Systematic analysis of phytochemicals in human milk, infant lumen and plasma, and immunomodulatory studies that differentiate maternal ingestion during lactation from pregnancy, are needed. Potential herb-drug interaction and other adverse effects should remain central to obstetric advising, but unless a plant is specifically shown as harmful, considering potential contributions to health of individuals and populations, blanket advisories against postpartum herbal use during lactation appear empirically unwarranted.

Citrus Polyphenols in Brain Health and Disease: Current Perspectives

In addition to essential micronutrients such as vitamin C, citrus fruits represent a considerably rich source of non-essential bioactive compounds, in particular flavanones which form a sub-set of the flavonoid group. Preclinical studies have demonstrated the neuroprotective potential of citrus flavonoids and have highlighted both the well-established (anti-inflammatory and anti-oxidative properties), and newly emerging (influence upon blood-brain barrier function/integrity) mechanistic actions by which these neurological effects are mediated. Encouragingly, results from human studies, although limited in number, appear to support this preclinical basis, with improvements in cognitive performance and disease risk observed across healthy and disease states. Therefore, citrus fruits - both as whole fruit and 100% juices - should be encouraged within the diet for their potential neurological benefit. In addition, there should be further exploration of citrus polyphenols to establish therapeutic efficacy, particularly in the context of well-designed human interventions.

Molecular insights into the therapeutic promise of targeting HMGB1 in depression

Depression is a common psychiatric disorder, the exact pathogenesis of which is still elusive. Studies have proposed that immunity disproportion and enhancement in proinflammatory cytokines might be linked with the development of depression. HMGB1 (High-mobility group box (1) protein has obtained more interest as an essential factor in inherent immune reactions and a regulating factor in various inflammation-related diseases. HMGB1 is a ubiquitous chromatin protein and is constitutively expressed in nucleated mammalian cells. HMGB1 is released by glial cells and neurons upon inflammasome activation and act as a pro-inflammatory cytokine. HMGB1 is a late mediator of inflammation and has been indicated as a major mediator in various neuroinflammatory diseases. Microglia, which is the brain immune cell, is stimulated by HMGB1 and released inflammatory mediators and induces chronic neurodegeneration in the CNS (central nervous system). In the current review, we aimed to investigate the role of HMGB1 in the pathogenesis of depression. The studies found that HMGB1 functions as proinflammatory cytokines primarily via binding receptors like RAGE (receptor for advanced glycation end product), TLR2 and TLR4 (Toll-like receptor 2 and 4). Further, HMGB1 added to the preparing impacts of stress-pretreatment and assumed a major function in neurodegenerative conditions through moderating neuroinflammation. Studies demonstrated that neuroinflammation played a major role in the development of depression. The patients of depression generally exhibited an elevated amount of proinflammatory cytokines in the serum, microglia activation and neuronal deficit in the CNS.

Modulatory action of environmental enrichment on hormonal and behavioral responses induced by chronic stress in rats: Hypothalamic renin-angiotensin system components

Environmental enrichment (EE) has been studied as a protocol that can improve brain plasticity and may protect against negative insults such as chronic stress. The aim of this study was to evaluate the effects of EE on the hormonal and behavioral responses induced by chronic mild unpredictable stress (CMS) in rats, considering the involvement of the renin-angiotensin system. Male adult rats were divided into 4 groups: control, CMS, EE, and CMS + EE, and the experimental protocol lasted for 7 weeks. EE was performed during 7 weeks, 5 days per week, 2 h per day. CMS was applied during weeks 3, 4, and 5. After the CMS (week 6), depression-like behavior was evaluated by forced swimming and sucrose consumption tests, anxiety level was evaluated using the elevated plus-maze test, and memory was evaluated using the Y-maze test. On week 7, the animals were euthanized and basal plasma levels of corticosterone and catecholamines were determined. The hypothalamus was isolated and tissue levels of angiotensin peptides were evaluated. CMS increased plasma corticosterone, norepinephrine, and epinephrine basal concentrations, induced depression-like behaviors, impaired memory, and increased hypothalamic angiotensin I, II, and IV concentrations. EE decreased stress hormones secretion, depression-like behaviors, memory impairment, and hypothalamic angiotensin II induced by stress. Reductions of anxiety-like behavior and norepinephrine secretion were observed in both stressed and unstressed groups. The results indicated that EE seemed to protect adult rats against hormonal and behavioral CMS effects, and that the reduction of angiotensin II could contribute to these effects.