The effects of EGb761 on lipopolysaccharide-induced depressive-like behaviour in C57BL/6J mice

Anti-Neuroinflammatory Effects of Ginkgo biloba Extract EGb 761 in LPS-Activated BV2 Microglial Cells

Inflammatory processes in the brain can exert important neuroprotective functions. However, in neurological and psychiatric disorders, it is often detrimental due to chronic microglial over-activation and the dysregulation of cytokines and chemokines. Growing evidence indicates the emerging yet prominent pathophysiological role of neuroinflammation in the development and progression of these disorders. Despite recent advances, there is still a pressing need for effective therapies, and targeting neuroinflammation is a promising approach. Therefore, in this study, we investigated the anti-neuroinflammatory potential of a marketed and quantified proprietary herbal extract of Ginkgo biloba leaves called EGb 761 (10-500 µg/mL) in BV2 microglial cells stimulated by LPS (10 ng/mL). Our results demonstrate significant inhibition of LPS-induced expression and release of cytokines tumor necrosis factor-α (TNF-α) and Interleukin 6 (IL-6) and chemokines C-X-C motif chemokine ligand 2 (CXCL2), CXCL10, c-c motif chemokine ligand 2 (CCL2) and CCL3 in BV2 microglial cells. The observed effects are possibly mediated by the mitogen-activated protein kinases (MAPK), p38 MAPK and ERK1/2, as well as the protein kinase C (PKC) and the nuclear factor (NF)-κB signaling cascades. The findings of this in vitro study highlight the anti-inflammatory properties of EGb 761 and its therapeutic potential, making it an emerging candidate for the treatment of neuroinflammatory diseases and warranting further research in pre-clinical and clinical settings.

Effect of Shenqi Jieyu formula on inflammatory response pathway in hippocampus of postpartum depression rats

Aim

To investigate whether SJF functions in similar manner as the key substance in the inflammatory process, soluble epoxide hydrolase (sEH) inhibitor, to inhibit the arachidonic acid metabolic pathway and nuclear factor kappa-B(NF-κB) signal path in the hippocampi of postpartum depression rats.

Methods

The rats were subcutaneous injected estradiol benzoate and progesterone to build PPD rat model. SJF, paroxetine hydrochloride and sEH inhibitor (AUDA) were used to treat PPD rats for 3 weeks. Then the morphological changes of hippocampi and various proteins were observed after that behavioral test were conducted in all 36 SD rats in six group: SJF, paroxetine, AUDA, PPD, sham and normal group.

Results

Weight, results of sucrose preference, upright times, total and center squares crossing decreased significantly (P < 0.01), whereas immobility time increased (P < 0.01). Results above were reversed in animals that in the SJF, paroxetine and AUDA groups. Hippocampal neurons in PPD rats partially degenerated with narrowed nuclei, increased autophagy and mitochondria bound to lysosomes were visible while the autophagy of hippocampal neurons in the paroxetine and AUDA group decreased, with a small amount of lysosomes. sEH, COX-2, 5-LOX, TNF-α, IL-1, IL-6, NF-κB p65, and Cor increased in hippocampi of PPD rats while EETs and 5-HT decreased. Protein expressions of Ibal, GFAP, p-IκBα, p65, and p-p65(S536)increased in PPD animals. Those changes were reversed by SJF, paroxetine and AUDA. Gene expressions of TNF-α, IL-1β, IL-6, 5-LOX, COX-2 and p65 increased in PPD rats and the changes of expression in these genes were reversed by paroxetine and AUDA. SJF reversed the gene expression changes of COX-2, TNF-α, and IL-1β.

Conclusion

SJF may have an analogous effect as sEH inhibitor to relieve depressive symptoms by suppressing inflammatory signaling pathways in hippocampi of PPD rats, which involves AA metabolic pathway and NF-κB signal pathway.

Multi-target drugs for the treatment of cognitive impairment and fatigue in post-COVID syndrome: focus on Ginkgo biloba and Rhodiola rosea

Cognitive impairment, depression and (mental) fatigue represent the most frequent neuropsychiatric symptoms of the post-COVID syndrome. Neuroinflammation, oxidative stress and mitochondrial dysfunction have been identified as common pathophysiological mechanisms underlying these symptoms. Attempts to treat post-COVID-associated cognitive impairment and fatigue with different drugs available for other diseases have not yet been successful. One probable explanation could be that these drugs work by one specific mechanism of action only and not in a broad multi-target way. Therefore, they will not address the broad pathophysiological spectrum possibly responsible for cognitive impairment, depression and fatigue in post-COVID syndrome. Notably, nearly all drugs currently under investigation for fatigue in post-COVID syndrome are rather addressing one single target instead of the several pathomechanisms underlying this condition. Contrary to this approach, herbal drugs often consist of many different ingredients with different pharmacological properties and pharmacological targets. Therefore, these drugs might be a promising approach for the treatment of the broad symptomatic presentation and the pathophysiological mechanisms of cognitive impairment and fatigue following a SARS-CoV-2 infection. Of these herbal drugs, extracts of Ginkgo biloba and Rhodiola rosea probably are the best investigated candidates. Their broad pharmacological spectrum in vitro and in vivo includes anti-oxidative, anti-inflammatory, antidepressant as well as properties reducing cognitive impairment and fatigue. In several studies, both drugs showed positive effects on physical and mental fatigue and impaired cognition. Moreover, depressive symptoms were also reduced in some studies. However, even if these results are promising, the data are still preliminary and require additional proof by further studies.

Loureirin B protects against cerebral ischemia/reperfusion injury through modulating M1/M2 microglial polarization via STAT6 / NF-kappaB signaling pathway

The latest research indicates that modulating microglial polarization from M1 to M2 phenotype may be a coping therapy for ischemic stroke. The present study thereby evaluated the effects of loureirin B (LB), a monomer compound extracted from Sanguis Draconis flavones (SDF), on cerebral ischemic injury and the potential mechanisms. The middle cerebral artery occlusion (MCAO) model was established in male Sprague-Dawley rats to induce cerebral ischemia/reperfusion (I/R) injury in vivo, and BV2 cells were exposed to oxygen-glucose deprivation and reintroduction (OGD/R) to mimic cerebral I/R injury in vitro. The results showed that LB significantly reduced infarct volume, neurological deficits and neurobehavioral deficits, apparently improved histopathological changes and neuronal loss in cortex and hippocampus of MCAO/R rats, markedly decreased the proportion of M1 microglia cells and the level of pro-inflammatory cytokines, and increased the proportion of M2 microglia and the level of anti-inflammatory cytokines both in vivo and in vitro. In addition, LB evidently improved the p-STAT6 expression and reduced the NF-κB (p-p65) expression after cerebral I/R injury in vivo and in vitro. IL-4 (a STAT6 agonist) exhibited a similar impact to that of LB, while AS1517499 (a STAT6 inhibitor) significantly reversed the effect of LB on BV-2 cells after OGD/R. These findings point to the protection of LB against cerebral I/R injury by modulating M1/M2 polarization of microglia via the STAT6/NF-κB signaling pathway, hence LB may be a viable treatment option for ischemic stroke.

Extracellular Vesicles: Emerging Roles in Developing Therapeutic Approach and Delivery Tool of Chinese Herbal Medicine for the Treatment of Depressive Disorder

Extracellular vesicles (EVs) are lipid bilayer-delimited particles released by cells, which play an essential role in intercellular communication by delivering cellular components including DNA, RNA, lipids, metabolites, cytoplasm, and cell surface proteins into recipient cells. EVs play a vital role in the pathogenesis of depression by transporting miRNA and effector molecules such as BDNF, IL34. Considering that some herbal therapies exhibit antidepressant effects, EVs might be a practical delivery approach for herbal medicine. Since EVs can cross the blood-brain barrier (BBB), one of the advantages of EV-mediated herbal drug delivery for treating depression with Chinese herbal medicine (CHM) is that EVs can transfer herbal medicine into the brain cells. This review focuses on discussing the roles of EVs in the pathophysiology of depression and outlines the emerging application of EVs in delivering CHM for the treatment of depression.

T helper cells in depression: central role of Th17 cells

Depression is one of the most common neuropsychiatric disorders in the world. While conventional pharmaceutical therapy targets monoaminergic pathway dysfunction, it has not been totally successful in terms of positive outcomes, remission, and preventing relapses. There is an increasing amount of evidence that neuroinflammation may play a significant part in the pathophysiology of depression. Among the key components of the neuroinflammatory pathways already known to be active are the T helper (Th) cells, especially Th17 cells. While various preclinical and clinical studies have reported increased levels of Th17 cells in both serum and brain tissue of laboratory model animals, contradictory results have argued against a pertinent role of Th17 cells in depression. Recent studies have also revealed a role for more pathogenic and inflammatory subsets of Th17 in depression, as well as IL-17A and Th17 cells in non-responsiveness to conventional antidepressant therapy. Despite recent advances, there is still a significant knowledge gap concerning the exact mechanism by which Th17 cells influence neuroinflammation in depression. This review first provides a short introduction to the major findings that led to the discovery of the role of Th cells in depression. The major subsets of Th cells known to be involved in neuroimmunology of depression, such as Th1, Th17, and T regulatory cells, are subsequently described, with an in-depth discussion on current knowledge about Th17 cells in depression.

An Antagonistic Peptide of Gpr1 Ameliorates LPS-Induced Depression through the Hypothalamic-Pituitary-Ovarian Axis

Depression affects the reproductive axis at the hypothalamus and pituitary levels, which has a significant impact on female fertility. It has been reported that G protein-coupled receptor 1 (Gpr1) mRNA is expressed in both the hypothalamus and ovaries. However, it is unclear whether there is a relationship between Gpr1 and depression, and its role in ovarian function is unknown. Here, the expression of Gpr1 was recorded in the hypothalamus of normal female mice, and co-localized with gonadotrophin-releasing hormone (GnRH) and corticotropin-releasing factor (CRF). We established a depression mouse model to evaluate the antidepressant effect of G5, an antagonistic peptide of Gpr1. The results show that an intraperitoneal injection of G5 improves depressant–like behaviors remarkably, including increased sucrose intake in the sucrose preference test and decreased immobility time in the forced swimming tests. Moreover, G5 treatment increased the release of reproductive hormone and the expression of ovarian gene caused by depression. Together, our findings reveal a link between depression and reproductive diseases through Gpr1 signaling, and suggest antagonistic peptide of Gpr1 as a potential therapeutic application for hormone-modulated depression in women.

An Antagonistic Peptide of Gpr1 Ameliorates LPS-Induced Depression through the Hypothalamic-Pituitary-Ovarian Axis

Depression affects the reproductive axis at the hypothalamus and pituitary levels, which has a significant impact on female fertility. It has been reported that G protein-coupled receptor 1 (Gpr1) mRNA is expressed in both the hypothalamus and ovaries. However, it is unclear whether there is a relationship between Gpr1 and depression, and its role in ovarian function is unknown. Here, the expression of Gpr1 was recorded in the hypothalamus of normal female mice, and co-localized with gonadotrophin-releasing hormone (GnRH) and corticotropin-releasing factor (CRF). We established a depression mouse model to evaluate the antidepressant effect of G5, an antagonistic peptide of Gpr1. The results show that an intraperitoneal injection of G5 improves depressant-like behaviors remarkably, including increased sucrose intake in the sucrose preference test and decreased immobility time in the forced swimming tests. Moreover, G5 treatment increased the release of reproductive hormone and the expression of ovarian gene caused by depression. Together, our findings reveal a link between depression and reproductive diseases through Gpr1 signaling, and suggest antagonistic peptide of Gpr1 as a potential therapeutic application for hormone-modulated depression in women.

Evidence that Ginkgo Biloba could use in the influenza and coronavirus COVID-19 infections

Coronavirus COVID-19 pandemic invades the world. Public health evaluates the incidence of infections and death, which should be reduced and need desperately quarantines for infected individuals. This article review refers to the roles of Ginkgo Biloba to reduce the risk of infection in the respiratory tract, the details on the epidemiology of corona COVID-19 and influenza, and it highlights how the Ginko Biloba could have been used as a novel treatment.Ginkgo Biloba can reduce the risk of infection by several mechanisms; these mechanisms involve Ginkgo Biloba contains quercetin and other constituents, which have anti-inflammatory and immune modulator effects by reducing pro-inflammatory cytokines concentrations. Cytokines cause inflammation which have been induced the injuries in lung lining.Some observational studies confirmed that Ginkgo Biloba reduced the risk of asthma, sepsis and another respiratory disease as well as it reduced the risk of cigarette smoking on respiratory symptoms. While other evidences suggested the characters of Ginkgo Biloba as an antivirus agent through several mechanisms. Ginkgolic acid (GA) can inhibit the fusion and synthesis of viral proteins, thus, it inhibit the Herpes Simplex Virus type1 (HSV-1), genome replication in Human Cytomegalovirus (HCMV) and the infections of the Zika Virus (ZIKV). Also, it inhibits the wide spectrum of fusion by inhibiting the three types of proteins that have been induced fusion as (Influenza A Virus [IAV], Epstein Barr Virus [EBV], HIV and Ebola Virus [EBOV]).The secondary mechanism of GA targeting inhibition of the DNA and protein synthesis in virus, greatly have been related to its strong effects, even afterward the beginning of the infection, therefore, it potentially treats the acute viral contaminations like (Measles and Coronavirus COVID-19). Additionally, it has been used topically as an effective agent on vigorous lesions including (varicella-zoster virus [VZV], HSV-1 and HSV-2). Ginkgo Biloba may be useful for treating the infected people with coronavirus COVID-19 through its beneficial effect. To assess those recommendations should be conducted with random control trials and extensive population studies.

Chinese Herbal Medicine for the Treatment of Depression: Effects on the Neuroendocrine-Immune Network

The neuroimmune and neuroendocrine systems are two critical biological systems in the pathogenesis of depression. Clinical and preclinical studies have demonstrated that the activation of the neuroinflammatory response of the immune system and hyperactivity of the hypothalamus–pituitary–adrenal (HPA) axis of the neuroendocrine system commonly coexist in patients with depression and that these two systems bidirectionally regulate one another through neural, immunological, and humoral intersystem interactions. The neuroendocrine-immune network poses difficulties associated with the development of antidepressant agents directed toward these biological systems for the effective treatment of depression. On the other hand, multidrug and multitarget Chinese Herbal Medicine (CHM) has great potential to assist in the development of novel medications for the systematic pharmacotherapy of depression. In this narrative essay, we conclusively analyze the mechanisms of action of CHM antidepressant constituents and formulas, specifically through the modulation of the neuroendocrine-immune network, by reviewing recent preclinical studies conducted using depressive animal models. Some CHM herbal constituents and formulas are highlighted as examples, and their mechanisms of action at both the molecular and systems levels are discussed. Furthermore, we discuss the crosstalk of these two biological systems and the systems pharmacology approach for understanding the system-wide mechanism of action of CHM on the neuroendocrine-immune network in depression treatment. The holistic, multidrug, and multitarget nature of CHM represents an excellent example of systems medicine in the effective treatment of depression.

Jmjd3 is involved in the susceptibility to depression induced by maternal separation via enhancing the neuroinflammation in the prefrontal cortex and hippocampus of male rats

Adverse childhood experience is a major risk factor for the onset of depression in adulthood. Neuroinflammation characterized by microglial activation and cytokine secretion is involved in susceptibility to depression induced by early life stress. Jumonji domain-containing protein 3 (Jmjd3), a trimethylated lysine 27 in histone 3 (H3K27me3) demethylase, can be activated by nuclear factor-kappa B (NF-κB), further regulating the expression of pro-inflammatory cytokines and resulting in neuroinflammation. However, its involvement in susceptibility to early life stress-related depression is unknown. In the current study, maternal separation (MS) was utilized as a model of early life stress and systemic lipopolysaccharide (LPS) administration in adulthood was used as a later-life challenge. Depressive- and anxiety-like behaviors and memory impairment were detected by behavioral tests. Microglial activation, pro-inflammatory cytokine expression, and NF-κB, Jmjd3, and H3K27me3 expression were detected in the prefrontal cortex and hippocampus in both infant and adult rats. Meanwhile, the Jmjd3 inhibitor GSK-J4 was used as an intervention in vivo and in vitro. Our results showed that MS induced depression-like behaviors and synchronously caused microglial activation, pro-inflammatory cytokine over-expression, NF-κB and Jmjd3 over-expression, and decreased H3K27me3 expression in infant rats. All these alterations could also be detected in adulthood. Seven-day LPS administration in adult rats induced similar changes of behaviors and biomarkers. Interestingly, compared with rats not exposed to MS, MS-exposed rats receiving LPS administration developed more severe depression-like behaviors and neuroinflammatory status, higher levels of NF-κB and Jmjd3 expression, and lower levels of H3K27me3 expression. In addition, LPS induced microglial activation, pro-inflammatory cytokine expression and increased Jmjd3 expression in vitro. Furthermore, GSK-J4 treatment alleviated these alterations in vivo and in vitro. Thus, our data indicate that Jmjd3 is involved in the susceptibility to depression induced by MS via enhancement of neuroinflammation in the prefrontal cortex and hippocampus of rats.

Anti-inflammatory and immune-modulatory properties of anemoside B4 isolated from Pulsatilla chinensis in vivo

BACKGROUND

Pulsatilla chinensis is commonly used for the treatment of cancers and inflammatory disorders in China. Our recent studies showed that anemoside B4, its major ingredient, possessed notable antioxidant and protected cisplatin-induced acute kidney injury in vivo. Furthermore, we found the protective effect might be involved its anti-inflammation activities. However, its anti-inflammatory mechanisms are not clear.

PURPOSE

In the present study, we extensively investigated the anti-inflammatory and immune-modulatory properties of anemoside B4 in vivo.

METHODS

To carry out this work, the xylene-induced ear edema and LPS-induced systemic inflammation of mice model was also used to evaluate the anti-inflammatory activity. Then, anti-inflammatory mechanism of anemoside B4 was further determined by pro-inflammatory cytokines production using enzyme-linked immunosorbent assay (ELISA) and nuclear factor-κ-gene binding (NF-κB) pathway activation by Western blot. At last, immuno-modulatory effects were observed by splenocyte proliferation assay, delayed type hypersensitivity assay (DTH) and T cell subtype assay in mice.

RESULTS

12.5-50 mg/kg anemoside B4 significantly suppressed xylene-induced mice ear edema. Furthermore, it ameliorated LPS-induced kidney and lung inflammation damage, which inhibited pro-inflammatory response by NF-κB pathway in mice. In addition, anemoside B4 decreased CD4⁺/CD8⁺ ratio, inhibited splenic lymphocyte proliferation and decreased DNFB-induced changes of ear thickness.

CONCLUSION

From these data, it can be concluded that anemoside B4 presented anti-inflammatory and immune-modulatory activities in vivo, and potentially be a novel natural anti-inflammatory drug candidate for treating inflammatory disorder.

Evaluation of the anti-inflammatory properties of the active constituents in Ginkgo biloba for the treatment of pulmonary diseases

Ginkgo biloba has long been used in ancient China for the treatment of cough, asthma, and other lung diseases. However, the active constituents in G. biloba for pulmonary disease treatment remain unclear. The objective of this study was to evaluate the anti-inflammatory active constituents in G. biloba and clarify their associated molecular mechanisms. The biological effects of different G. biloba extracts were evaluated in an ovalbumin-induced allergic mouse model. Anti-inflammatory compounds were present in the ethyl acetate phase of the extract, which were analysed by HPLC-MS. Biflavones were identified as the main compounds, which were further evaluated by docking calculations. Leukocyte elastase showed a high fit score with ginkgetin, one of the identified biflavones. The lowest binding free energy was -6.69 kcal mol-1. The effects of biflavones were investigated in vivo and in vitro. Ginkgetin markedly suppressed the abnormal expression of the Akt and p38 pathways in human neutrophil elastase (HNE)-stimulated A549 cells. Biflavones also decreased MUC5AC mRNA expression in HNE-stimulated A549 cells and the allergic mouse model. Inflammatory cells (neutrophils) and cytokines (IL-8) also decreased in mice treated with biflavones. The results suggest that G. biloba biflavones could inhibit the activity of leukocyte elastase. This in turn implicates G. biloba as a functional food for the treatment of airway inflammation.

Botanicals as modulators of depression and mechanisms involved

Depression is the most disastrous mood disorder affecting the health of individuals. Conventional treatments with chemical compounds for depression have limitations, while herbal medicine has unique therapeutic effects. This paper introduces the pharmacological basis and biological mechanisms underlying the botanical antidepressants over the past 5 years. Based upon the specific therapeutic targets or mechanisms, we analyzed the pathological roles of monoamine neurotransmitters, the hypothalamic-pituitary-adrenal axis, inflammation, oxidative stress, synaptic plasticity performed in antidepressant of the botanicals. In addition, gut flora and neurogenesis were also preferentially discussed as treatment approaches. Based on the complex pathogenesis of depression, we suggested that mixed use of botanicals, namely prescription would be more suitable for treatment of depression. In addition, neural circuit affected by botanicals or active components should also attract attention as the botanicals have potential to be developed into fast-acting antidepressants. Finally, gut flora might be a new systemic target for the treatment of depression by botanicals. This review would strength botanical medicine as the antidepressant and also provides an overview of the potential mechanisms involved.

Ameliorative effect of fisetin against lipopolysaccharide and restraint stress-induced behavioral deficits via modulation of NF-κB and IDO-1

BACKGROUND

Fisetin, a plant active polyphenol, is well known for its antioxidant and free radical scavenging activities. The present study was designed to explore the detailed molecular mechanism underlying its neuroprotective effects.

METHODS

The young male mice were either administered a single dose of lipopolysaccharide (0.83 mg/kg) or subjected to restraint stress (6 h per day for 28 days) to induce behavioral deficits in different groups. Fisetin (15 mg/kg) was orally administered for the last 14 days of the study.

RESULTS

Lipopolysaccharide (LPS) as well as restraint stress (RS) exposure caused behavioral alterations (anxiety and depressive-like behavior). Gene expression analysis showed upregulation of nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) and indoleamine 2,3-dioxygenase (IDO)-1 gene expression along with downregulation of Nrf-2 (nuclear factor erythroid 2-related factor 2), HO-1 (heme oxygenase-1), and ChAT (choline acetyltransferase) gene expression level in RS and RS+LPS groups. Fisetin administration significantly ameliorated behavioral and neurochemical deficits in LPS, RS, and RS+LPS groups.

CONCLUSION

These findings clearly indicated that fisetin administration improved behavioral functions and suppressed the NF-κB and IDO-1 (indoleamine 2,3-dioxygenase) activation along with their antioxidant effect, suggesting fisetin as an intriguing nutraceutical for the management of inflammation-associated neurological disorders.

Endogenous Omega (n)-3 Fatty Acids in Fat-1 Mice Attenuated Depression-Like Behavior, Imbalance between Microglial M1 and M2 Phenotypes, and Dysfunction of Neurotrophins Induced by Lipopolysaccharide Administration

n-3 polyunsaturated fatty acids (PUFAs) have been reported to improve depression. However, PUFA purities, caloric content, and ratios in different diets may affect the results. By using Fat-1 mice which convert n-6 to n-3 PUFAs in the brain, this study further evaluated anti-depressant mechanisms of n-3 PUFAs in a lipopolysaccharide (LPS)-induced model. Adult male Fat-1 and wild-type (WT) mice were fed soybean oil diet for 8 weeks. Depression-like behaviors were measured 24 h after saline or LPS central administration. In WT littermates, LPS reduced sucrose intake, but increased immobility in forced-swimming and tail suspension tests. Microglial M1 phenotype CD11b expression and concentrations of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-17 were elevated, while M2 phenotype-related IL-4, IL-10, and transforming growth factor (TGF)-β1 were decreased. LPS also reduced the expression of brain-derived neurotrophic factor (BDNF) and tyrosine receptor kinase B (Trk B), while increasing glial fibrillary acidic protein expression and pro-BDNF, p75, NO, and iNOS levels. In Fat-1 mice, LPS-induced behavioral changes were attenuated, which were associated with decreased pro-inflammatory cytokines and reversed changes in p75, NO, iNOS, and BDNF. Gas chromatography assay confirmed increased n-3 PUFA levels and n-3/n-6 ratios in the brains of Fat-1 mice. In conclusion, endogenous n-3 PUFAs may improve LPS-induced depression-like behavior through balancing M1 and M2-phenotypes and normalizing BDNF function.

Anhedonia as a clinical correlate of inflammation in adolescents across psychiatric conditions

Objectives: Peripheral inflammation has been associated with multiple psychiatric disorders, particularly with depression. However, findings remain inconsistent and unreproducible, most likely due to the disorder's heterogeneity in phenotypic presentation. Therefore, in the present study, in an effort to account for inter-individual differences in symptom severity, we utilised a dimensional approach to assess the relationships between a broad panel of inflammatory cytokines and key psychiatric symptoms (i.e. depression, anhedonia, anxiety, fatigue and suicidality) in adolescents across psychiatric disorders. We hypothesised that only anhedonia (reflecting deficits of reward function) will be associated with inflammation.Methods: Participants were 54 psychotropic medication-free adolescents with diverse psychiatric conditions and 22 healthy control (HC) adolescents, aged 12-20. We measured 41 cytokines after in vitro lipopolysaccharide stimulation. Mann-Whitney U and Spearman correlation tests examined group comparison and associations, respectively, while accounting for multiple comparisons and confounds, including depression severity adolescent.Results: There were no group differences in cytokine levels. However, as hypothesised, within the psychiatric group, only anhedonia was associated with 19 cytokines, including haematopoietic growth factors, chemokines, pro-inflammatory cytokines, and anti-inflammatory cytokines.Conclusions: Our findings suggest that general inflammation may induce reward dysfunction, which plays a salient role across psychiatric conditions, rather than be specific to one categorical psychiatric disorder.

TLR4-NF-κB Signal Involved in Depressive-Like Behaviors and Cytokine Expression of Frontal Cortex and Hippocampus in Stressed C57BL/6 and ob/ob Mice

Studies found that elevated levels of cytokines such as interleukin- (IL-) 1β, IL-6, and tumor necrosis factor-α (TNF-α) are closely associated with the pathogenesis of depression. Obesity providing a low-grade inflammation state was proposed to be implicated in susceptibility to depression in obesity. However, the alterations of cytokines and the TLR4-NF-κB signal in the brain of normal-weight and obese mice under stress have not been fully elucidated. This study used chronic unpredictable mild stress (CUMS) to induce a depressive-like behavior in an animal model and examine depressive-like behaviors, memory changes, and serum corticosterone levels, as well as the expressions of cytokines and NF-κB in the frontal cortex and hippocampus. We aimed to observe the role of neuroinflammation in susceptibility to depression in obesity under CUMS. In addition, we investigated the protective effect of inhibiting the TLR4-NF-κB signal. Our results demonstrated that CUMS induced depressive-like behavior and spatial memory damage, higher level of serum corticosterone, and overexpression of cytokines and NF-κB in the frontal cortex and hippocampus in both C57BL/6 and ob/ob mice. ob/ob mice displayed serious behavioral disorder and higher levels of IL-1β, IL-6, TNF-α, and NF-κB. Our results concluded that a hyperactive TLR4-NF-κB signal and higher level of cytokines are involved in susceptibility to depression in stressed obese mice.

[Cerebral insulin resistance: current concepts of the pathogenesis and possible therapeutic strategies]

The review presents current concepts about the problem of cerebral insulin resistance (IR). It has now been established that cerebral IR plays a key role in the pathogenesis of degenerative and metabolic diseases of the brain. Based on literature data and own clinical experience, the authors recommend to use the standardized extract of ginkgo biloba EGb761 as a cellular protector, which increases insulin sensitivity of cells and reduces atherogenesis, in order to improve cognitive functions and quality of life in patients with diabetes mellitus.

The Dopamine Receptor D3 Regulates Lipopolysaccharide-Induced Depressive-Like Behavior in Mice

BACKGROUND

The altered expression and function of dopamine receptor D3 (D3R) in patients and animal models have been correlated with depression disease severity. However, the morphological alterations and biological effects of D3R in the brain after inflammation-induced depressive-like behavior remain elusive.

METHODS

In the present study, we ascertained the changes of D3R expression in the brain regions after depressive-like behavior induced by peripheral administration of lipopolysaccharide (LPS). Protein levels of proinflammatory cytokines, brain-derived neurotrophic factor (BDNF), and extracellular signal-regulated kinase (ERK1/2)-cAMP-response element-binding protein (CREB) signaling pathway after activation or inhibition of D3R in the brain of depressive mice were also investigated.

RESULTS

LPS caused a significant reduction of D3R in the ventral tegmental area (VTA), medial prefrontal cortex (mPFC), and nucleus accumbens (NAc), which are areas related to the mesolimbic dopaminergic system. Pretreatment with pramipexole (PPX), a preferential D3R agonist, showed antidepressant effects on LPS-induced depression-like behavior through preventing changes in LPS-induced proinflammatory cytokines (tumour necrosis factor-α, interleukin-1β, and interleukin-6), BDNF, and ERK1/2-CREB signaling pathway in the VTA and NAc. In opposition, treatment with a D3R selective antagonist NGB 2904 alone made mice susceptible to depression-like effects and caused changes in accordance with the LPS-induced alterations in proinflammatory cytokines, BDNF, and the ERK1/2-CREB signaling pathway in the mPFC and NAc.

CONCLUSIONS

These findings provide a relevant mechanism for D3R in LPS-induced depressive-like behavior via its mediation of proinflammatory cytokines and potential cross-effects between BDNF and the ERK1/2-CREB signaling pathway.

Dynamic Effects of Early Adolescent Stress on Depressive-Like Behaviors and Expression of Cytokines and JMJD3 in the Prefrontal Cortex and Hippocampus of Rats

Aims: Expression of inflammatory cytokines in the brain has been reported to be involved in the pathogenesis of and susceptibility to depression. Jumonji domain-containing 3 (Jmjd3), which is a histone H3 lysine 27 (H3K27) demethylase and can regulate microglial activation, has been regarded as a crucial element in the expression of inflammatory cytokines. Furthermore, recent studies highlighted the fact that lipopolysaccharides induce depressive-like behaviors and higher Jmjd3 expression and lower H3K27me3 expression in the brain. However, whether the process of Jmjd3 mediating inflammatory cytokines was involved in the susceptibility to depression due to early-life stress remained elusive. Methods: Rats exposed to chronic unpredictable mild stress (CUMS) in adolescence were used in order to detect dynamic alterations in depressive-like behaviors and expression of cytokines, Jmjd3, and H3K27me3 in the prefrontal cortex and hippocampus. Moreover, minocycline, an inhibitor of microglial activation, was employed to observe the protective effects. Results: Our results showed that CUMS during the adolescent period induced depressive-like behaviors, over-expression of cytokines, and increased Jmjd3 and decreased H3K27me3 expression in the prefrontal cortex and hippocampus of both adolescent and adult rats. However, minocycline relieved all the alterations. Conclusion: The study revealed that Jmjd3 might be involved in the susceptibility to depressive-like behaviors by modulating H3K27me3 and pro-inflammatory cytokine expression in the prefrontal cortex and hippocampus of rats that had been stressed during early adolescence.

Metabolite-related antidepressant action of diterpene ginkgolides in the prefrontal cortex

PURPOSE

Ginkgo biloba extract (GBE) contains diterpene ginkgolides (DGs), which have been shown to have neuroprotective effects by a number of previous studies. We previously demonstrated part of the action of DG. However, the impact of DG on the prefrontal cortex (PFC) remains unclear. Here, we evaluated the effects of DG and venlafaxine (for comparison) on behavioral and metabolite changes in the PFC using mice models and gas chromatography-mass spectrometry-based metabolomics.

MATERIALS AND METHODS

Mice were randomly divided into control (saline), DG (12.18 mg/kg) and venlafaxine (16 mg/kg) groups. After 2 weeks of treatment, depression and anxiety-related behavioral tests were performed. Metabolic profiles of the PFC were detected by gas chromatography-mass spectrometry.

RESULTS

The DG group exhibited positive effects in the sucrose preference test. The differential metabolites were mainly related to amino acid metabolism, energy metabolism and lipid metabolism. The results indicated that the DG group exhibited perturbed lipid metabolism, molecular transport and small-molecule biochemistry in the PFC. Compared with the control group, pathway analysis indicated that venlafaxine and DG had similar effects on alanine, aspartate and glutamate metabolism.

CONCLUSION

These findings demonstrate that DG has antidepressant-like, but not anxiolytic-like, effects in mice, suggesting that it might have therapeutic potential for the treatment of major depressive disorder.

Botanicals as Modulators of Neuroplasticity: Focus on BDNF

The involvement of brain-derived neurotrophic factor (BDNF) in different central nervous system (CNS) diseases suggests that this neurotrophin may represent an interesting and reliable therapeutic target. Accordingly, the search for new compounds, also from natural sources, able to modulate BDNF has been increasingly explored. The present review considers the literature on the effects of botanicals on BDNF. Botanicals considered were Bacopa monnieri (L.) Pennell, Coffea arabica L., Crocus sativus L., Eleutherococcus senticosus Maxim., Camellia sinensis (L.) Kuntze (green tea), Ginkgo biloba L., Hypericum perforatum L., Olea europaea L. (olive oil), Panax ginseng C.A. Meyer, Rhodiola rosea L., Salvia miltiorrhiza Bunge, Vitis vinifera L., Withania somnifera (L.) Dunal, and Perilla frutescens (L.) Britton. The effect of the active principles responsible for the efficacy of the extracts is reviewed and discussed as well. The high number of articles published (more than one hundred manuscripts for 14 botanicals) supports the growing interest in the use of natural products as BDNF modulators. The studies reported strengthen the hypothesis that botanicals may be considered useful modulators of BDNF in CNS diseases, without high side effects. Further clinical studies are mandatory to confirm botanicals as preventive agents or as useful adjuvant to the pharmacological treatment.

Hesperidin Alleviates Lipopolysaccharide-Induced Neuroinflammation in Mice by Promoting the miRNA-132 Pathway

Previous studies have demonstrated that hesperidin, a flavanone glycoside from citrus fruits, produces antidepressant-like effects in both mice and rats. However, whether these effects are mediated by pro-inflammatory cytokines remains unknown. In the present study, we attempted to investigate the effects of hesperidin on the depressive-like behavior; the serum corticosterone concentrations; and the interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α) levels in lipopolysaccharide (LPS)-induced depression-like mice. In particular, we evaluated the miRNA-132 expression after LPS and hesperidin treatment. We found that LPS injection not only decreased the sucrose preference and increased the serum corticosterone levels but also elevated IL-1β, IL-6, and TNF-α in the prefrontal cortex. More importantly, LPS down-regulated the expression of miRNA-132. Pre-treatment with hesperidin (25, 50, 100 mg/kg) for 7 days prevented these abnormalities induced by LPS injection. In contrast, this effect of hesperidin was abolished by a miRNA-132 antagomir. Taken together, these results suggest that the antidepressant-like mechanisms of hesperidin are at least partially related to decreased pro-inflammatory cytokine levels via the miRNA-132 pathway in the brain.

EGb761 attenuates depressive-like behaviours induced by long-term light deprivation in C57BL/6J mice through inhibition of NF-κB-IL-6 signalling pathway

Our previous investigation found that Ginkgo extract EGb761 could attenuate the depressive-like behaviours induced by a single injection of lipopolysaccharide in mice. However, it has not been investigated whether EGb761 is effective on depressive-like behaviours induced by long-term light deprivation and whether its effects are associated with the inhibition of NF-κB-IL-6 signalling pathway. In this study, three groups (vehicle group, EGb761 low-dose group, and EGb761 high-dose group) of C57BL/6J male mice were exposed to constant darkness for four weeks. The control mice remained on a 12 : 12 light-dark cycle. Depressive-like behaviours were evaluated by tail suspension test (TST), forced swim test (FST), and sucrose preference test (SPT). Spontaneous locomotor activity was evaluated by open field test (OFT). Levels of IL-6, IL-6 mRNA, NF-κB p65, phospho-NF-κB p65, IκBα, and phospho-IκBα were measured using Elisa, western blotting, or PCR assays. NF-κB p65 DNA binding activity was evaluated using Chemi Transcription Factor Assay Kit. Results showed long-term light deprivation prolonged the immobile time in TST and FST, shortened the latency to immobility in FST, reduced spontaneous locomotor activity in OFT, decreased sucrose preference in SPT, and increased levels of IL-6, IL-6 mRNA, NF-κB p65, phospho-NF-κB p65, and phospho-IκBα in hippocampal tissue. EGb761 dose-dependently reversed the changes of the above parameters induced by long-term light deprivation, without affecting spontaneous locomotor activity. We conclude that EGb761 could attenuate the depressive-like behaviours and inhibit the NF-κB-IL-6 signalling pathway in a light-deprivation-induced mouse model of depression.

GC-MS-based metabolomic study on the antidepressant-like effects of diterpene ginkgolides in mouse hippocampus

Ginkgo biloba extract (GBE), including EGb-761, have been suggested to have antidepressant activity based on previous behavioral and biochemical analyses. However, because GBE contain many constituents, the mechanisms underlying this suggested antidepressant activity are unclear. Here, we investigated the antidepressant-like effects of diterpene ginkgolides (DG), an important class of constituents in GBE, and studied their effects in the mouse hippocampus using a GC-MS-based metabolomics approach. Mice were randomly divided into five groups and injected daily until testing with 0.9% NaCl solution, one of three doses of DG (4.06, 12.18, and 36.54mg/kg), or venlafaxine. Sucrose preference (SPT) and tail suspension (TST) tests were then performed to evaluate depressive-like behaviors in mice. DG (12.18 and 36.54mg/kg) and venlafaxine (VLX) administration significantly increased hedonic behavior in mice in the SPT. DG (12.18mg/kg) treatment also shortened immobility time in the TST, suggestive of antidepressant-like effects. Significant differences in the metabolic profile in the DG (12.18mg/kg) compared with the control or VLX group indicative of an antidepressant-like effect were observed using multivariate analysis. Eighteen differential hippocampal metabolites were identified that discriminated the DG (12.18mg/kg) and control groups. These biochemical changes involved neurotransmitter metabolism, oxidative stress, glutathione metabolism, lipid metabolism, energy metabolism, and kynurenic acid, providing clues to the therapeutic mechanisms of DG. Thus, this study showed that DG has antidepressant-like activities in mice and shed light on the biological mechanisms underlying the effects of diterpene ginkgolides on behavior, providing an important drug candidate for the treatment of depression.

A murine model of peripheral irradiation-induced fatigue

PURPOSE

Fatigue is the most ubiquitous side effect of cancer treatment, but its etiology remains elusive. Further investigations into cancer-related fatigue pathobiology necessitate the expanded use of animal models. This study describes the development of a murine model of radiation-induced fatigue.

METHODS

Voluntary wheel running activity measured fatigue in 5-8 week-old, male C57BL/6 mice before and after γ irradiation totaling 2400cGy (3 consecutive days×800cGy daily fractionated doses) to the lower abdominal areas. Three trials confirmed fatigue behavior at this dose. Anhedonia, body weight, and hemoglobin were also measured. Gastrointestinal, skeletal muscle, and bone marrow tissue samples were evaluated for signs of damage.

RESULTS

In two validation trials, irradiated mice (trial 1, n=8; trial 2, n=8) covered less cumulative distance in kilometers post-irradiation (trial 1, mean=115.3±12.3; trial 2, mean=113.6±21.8) than sham controls (trial 1, n=5, mean=126.3±5.7, p=0.05; trial 2, n=8, mean=140.9±25.4, p=0.02). Decreased mean daily running distance and speed were observed during the last four hours of the dark cycle in irradiated mice compared to controls for two weeks post-irradiation. There were no differences in saccharin preference or hemoglobin levels between groups, no effect of changes in body weight or hemoglobin on wheel running distance, additionally, histology showed no damage to muscle, bone marrow, or gastrointestinal integrity, with the latter confirmed by ELISA.

CONCLUSION

We characterized a novel mouse model of fatigue caused by peripheral radiation and not associated with anemia, weight changes, or anhedonia. This model provides opportunities for detailed study of the mechanisms of radiation-induced fatigue.