(+)-Sesamin attenuates chronic unpredictable mild stress-induced depressive-like behaviors and memory deficits via suppression of neuroinflammation

Synbiotic therapy with Clostridium sporogenes and xylan promotes gut-derived indole-3-propionic acid and improves cognitive impairments in an Alzheimer's disease mouse model

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized primarily by cognitive impairment. Recent investigations have highlighted the potential of nutritional interventions that target the gut-brain axis, such as probiotics and prebiotics, in forestalling the onset of AD. In this study, whole-genome sequencing was employed to identify xylan as the optimal carbon source for the tryptophan metabolism regulating probiotic Clostridium sporogenes (C. sporogenes). Subsequent in vivo studies demonstrated that administration of a synbiotic formulation comprising C. sporogenes (1 × 1010 CFU per day) and xylan (1%, w/w) over a duration of 30 days markedly enhanced cognitive performance and spatial memory faculties in the 5xFAD transgenic AD mouse model. The synbiotic treatment significantly reduced amyloid-β (Aβ) accumulation in the cortex and hippocampus of the brain. Importantly, synbiotic therapy substantially restored the synaptic ultrastructure in AD mice and suppressed neuroinflammatory responses. Moreover, the intervention escalated levels of the microbial metabolite indole-3-propionic acid (IPA) and augmented the relative prevalence of IPA-synthesizing bacteria, Lachnospira and Clostridium, while reducing the dominant bacteria in AD, such as Aquabacterium, Corynebacterium, and Romboutsia. Notably, synbiotic treatment also prevented the disruption of gut barrier integrity. Correlation analysis indicated a strong positive association between gut microbiota-generated IPA levels and behavioral changes. In conclusion, this study demonstrates that synbiotic supplementation significantly improves cognitive and intellectual deficits in 5xFAD mice, which could be partly attributed to enhanced IPA production by gut microbiota. These findings provide a theoretical basis for considering synbiotic therapy as a novel microbiota-targeted approach for the treatment of metabolic and neurodegenerative diseases.

Sesamin ameliorates nonalcoholic hepatic steatosis by inhibiting CD36-mediated hepatocyte lipid accumulation in vitro and in vivo

Hepatic steatosis is a critical factor in the development of nonalcoholic steatohepatitis (NASH). Sesamin (Ses), a functional lignan isolated from Sesamum indicum, possesses hypolipidemic, liver-protective, anti-hypertensive, and anti-tumor properties. Ses has been found to improve hepatic steatosis, but the exact mechanisms through which Ses achieves this are not well understood. In this study, we observed the anti-hepatic steatosis effects of Ses in palmitate/oleate (PA/OA)-incubated primary mouse hepatocytes, AML12 hepatocytes, and HepG2 cells, as well as in high-fat, high-cholesterol diet-induced NASH mice. RNA sequencing analysis revealed that cluster of differentiation 36 (CD36), a free fatty acid (FA) transport protein, was involved in the Ses-mediated inhibition of hepatic fat accumulation. Moreover, the overexpression of CD36 significantly increased hepatic steatosis in both Ses-treated PA/OA-incubated HepG2 cells and NASH mice. Furthermore, Ses treatment suppressed insulin-induced de novo lipogenesis in HepG2 cells, which was reversed by CD36 overexpression. Mechanistically, we found that Ses ameliorated NASH by inhibiting CD36-mediated FA uptake and upregulation of lipogenic genes, including FA synthase, stearoyl-CoA desaturase 1, and sterol regulatory element-binding protein 1. The findings of our study provide novel insights into the potential therapeutic applications of Ses in the treatment of NASH.

Bergamot essential oil improves CUMS-induced depression-like behaviour in rats by protecting the plasticity of hippocampal neurons

Bergamot essential oil (BEO) is an extract of the bergamot fruit with significant neuroprotective effect. This study was to investigate the effects and the underlying mechanism of BEO in mitigating depression. GC-MS were used to identify its constituents. Antidepressive properties of BEO were evaluated by sucrose preference test (SPT), force swimming test (FST) and open field test (OFT). Nissl staining was used to determine the number of Nissl bodies in hippocampus (HIPP) of rats. Changes in HIPP dendritic length and dendritic spine density were detected by Golgi-Cox staining. Immunohistochemistry and Western blot were used to detect the postsynaptic density protein-95 (PSD-95) and synaptophysin (SYP) in the HIPP of rats. The enzyme-linked immunosorbent assay was used to determine the 5-hydroxytryptamine (5-HT), insulin-like growth factor 1 (IGF-1) and interleukin-1β (IL-1β) in the HIPP, serum and cerebrospinal fluid (CSF) of rats. Inhaled BEO significantly improved depressive behaviour in chronic unpredictable mild stress (CUMS) rats. BEO increased Nissl bodies, dendritic length and spine density, PSD-95 and SYP protein in the HIPP. Additionally, BEO upregulated serum 5-HT, serum and CSF IGF-1, while downregulating serum IL-1β. Collectively, inhaled BEO mitigates depression by protecting the plasticity of hippocampal neurons, hence, providing novel insights into treatment of depression.

Targeting autophagy to counteract neuroinflammation: A novel antidepressant strategy

Depression is a common disease that affects physical and mental health and imposes a considerable burden on afflicted individuals and their families worldwide. Depression is associated with a high rate of disability and suicide. It causes a severe decline in productivity and quality of life. Unfortunately, the pathophysiological mechanisms underlying depression have not been fully elucidated, and the risk of its treatment is still presented. Studies have shown that the expression of autophagic markers in the brain and peripheral inflammatory mediators are dysregulated in depression. Autophagy-related genes regulate the level of autophagy and change the inflammatory response in depression. Depression is related to several aspects of immunity. The regulation of the immune system and inflammation by autophagy may lead to the development or deterioration of mental disorders. This review highlights the role of autophagy and neuroinflammation in the pathophysiology of depression, sumaries the autophagy-targeting small moleculars, and discusses a novel therapeutic strategy based on anti-inflammatory mechanisms that target autophagy to treat the disease.

Effects of the ApoE genotype on cognitive function in aging mice fed with a high-fat diet and the protective potential of n-3 polyunsaturated fatty acids

The ApoE4 allele is the strongest genetic determinant for Alzheimer's disease (AD), while obesity is a strong environmental risk for AD. The modulatory effect of the ApoE genotype on aging-related cognitive function in tandem with a high-fat diet (HFD) remains uncertain. This study aimed to elucidate the effects of ApoE3/ApoE4 genotypes in aged mice exposed to a HFD, and the benefits of n-3 polyunsaturated fatty acids (PUFAs) from fish oil. Remarkably, the HFD led to weight gain and lipid accumulation, more pronounced in ApoE3 mice, while ApoE4 mice experienced exacerbated cerebral insulin resistance, neuroinflammation, and oxidative stress. Critically, n-3 PUFAs modulated the cerebral insulin signaling via the IRS-1/AKT/GLUT4 pathway, mitigated microglial hyperactivity, and reduced IL-6 and MDA levels, thereby counteracting cognitive deficits. These findings highlight the contrasting impacts of ApoE genotypes on aging mice exposed to a HFD, supporting n-3 PUFAs as a strategic nutritional intervention for brain health, especially for ApoE4 carriers.

Negative Association of Lignan and Phytosterol Intake with Stress Perception during the COVID-19 Pandemic-A Polish Study on Young Adults

BACKGROUND

There has been an increasing global prevalence of depression and other psychiatric diseases in recent years. Perceived stress has been proven to be associated with psychiatric and somatic symptoms. Some animal and human studies have suggested that consuming foods abundant in lignans and phytosterols may be associated with lower levels of stress, depression, and anxiety. Still, the evidence is not yet strong enough to draw firm conclusions. Thus, we investigated the association between dietary intake of these phytochemicals and the level of stress experienced by adult individuals.

METHODS

Diet was assessed using self-reported 7-day dietary records. The intakes of lignans and phytosterols were estimated using databases with their content in various food products. The Perceived Stress Scale (PSS) was implemented to measure the level of perceived stress. A logistic regression analysis was used to test for associations.

RESULTS

The odds of elevated PSS were negatively associated with dietary intake of total phytosterols, stigmasterol, and β-sitosterol, with evidence of a decreasing trend across tertiles of phytochemicals. The analysis for doubling the intake reinforced the aforementioned relationships and found protective effects against PSS for total lignans, pinoresinol, and campesterol.

CONCLUSIONS

Habitual inclusion of lignans and phytosterols in the diet may play a role in psychological health. To address the global outbreak of depression and other mental health issues triggered by stress, it is important to take a holistic approach. There is a need to develop effective strategies for prevention and treatment, among which certain dietary interventions such as consumption of products abundant in lignans and phytosterols may play a substantial role.

Sesamin ameliorates nonalcoholic steatohepatitis through inhibiting hepatocyte pyroptosis in vivo and in vitro

Sesamin (Ses) is a natural lignan abundantly present in sesame and sesame oil. Pyroptosis, a newly identified type of pro-inflammatory programmed necrosis, contributes to the development of non-alcoholic steatohepatitis (NASH) when hepatocyte pyroptosis is excessive. In this study, Ses treatment demonstrated an improvement in hepatic damage in mice with high-fat, high-cholesterol diet-induced NASH and palmitate (PA)-treated mouse primary hepatocytes. Notably, we discovered, for the first time, that Ses could alleviate hepatocyte pyroptosis both in vivo and in vitro. Furthermore, treatment with phorbol myristate acetate, a protein kinase Cδ (PKCδ) agonist, increased PKCδ phosphorylation and attenuated the protective effects of Ses against pyroptosis in PA-treated mouse primary hepatocytes. Mechanistically, Ses treatment alleviated hepatocyte pyroptosis in NASH, which was associated with the regulation of the PKCδ/nod-like receptor family CARD domain-containing protein 4/caspase-1 axis. This study introduces a novel concept and target, suggesting the potential use of functional factors in food to alleviate liver damage caused by NASH.

Preparation and characterization of brain-targeted polymeric nanocarriers (Frankincense-PMBN-lactoferrin) and in-vivo evaluation on an Alzheimer's disease-like rat model induced by scopolamine

Experiments have demonstrated that frankincense may offer protection against scopolamine-induced Alzheimer's disease by mitigating cholinergic dysfunction and inhibiting inflammatory mediators. Nevertheless, its instability and limited water solubility lead to diminished medicinal efficacy. In this study, we utilized PMBN (poly [MPC-co-(BMA)-co-(MEONP)]) as a nanocarrier for targeted brain drug delivery of frankincense, employing lactoferrin as a ligand for precise targeting. Characterization of nanoparticle properties was conducted through FTIR and FESEM analysis, and the in-vitro drug release percentage from the nanoparticles was quantified. To induce Alzheimer's-like dementia in rats, scopolamine was intraperitoneally administered at a dose of 1 mg/kg/day for 14 days. Subsequently, behavioral assessments (Y-maze, passive avoidance test, tail suspension test) were performed, followed by evaluations of acetylcholinesterase (AChE), reduced glutathione (GSH), catalase (CAT), and brain histopathology at the conclusion of the treatment period. The results revealed that the nanoparticles had a size of 106.6 nm and a zeta potential of -3.8 mV. The maximum release of frankincense in the PBS environment from PMBN nanoparticles was 18.2 %, in accordance with the Peppas model. Behavioral tests indicated that targeted drug nanoparticles (F-PMBN-Lf) exhibited the capability to alleviate stress and depression while enhancing short-term memory in scopolamine-induced animals. Additionally, F-PMBN-Lf counteracted the scopolamine-induced elevation of AChE activity and GSH levels. However, it resulted in decreased activity of the antioxidant enzyme CAT compared to the scopolamine group. Histological analysis of brain tissue suggested that F-PMBN-Lf exerted a notable neuroprotective effect, preserving neuronal cells in contrast to the scopolamine-induced group. It appears that the polymer nanoparticles containing this plant extract have introduced a novel neuroprotective approach for the treatment of Alzheimer's disease.

Sesamin mitigates lead-induced behavioral deficits in male rats: The role of oxidative stress

Lead (Pb) is a well-known toxic pollutant that has negative effects on behavioral functions. Sesamin, a phytonutrient of the lignan class, has shown neuroprotective effects in various neurological disorder models. The present study was undertaken to evaluate the putative protective effects of sesamin against Pb-induced behavioral deficits and to identify the role of oxidative stress in male rats. The rats were exposed to 500 ppm of Pb acetate in their drinking water and simultaneously treated orally with sesamin at a dose of 30 mg/kg/day for eight consecutive weeks. Standard behavioral paradigms were used to assess the behavioral functions of the animals during the eighth week of the study. Subsequently, oxidative stress factors were evaluated in both the cerebral cortex and hippocampal regions of the rats. The results of this study showed that Pb exposure triggered anxiety-/depression-like behaviors and impaired object recognition memory, but locomotor activity was indistinguishable from the normal control rats. These behavioral deficiencies were associated with suppressed enzymatic and non-enzymatic antioxidant levels, and enhanced lipid peroxidation in the investigated brain regions. Notably, correlations were detected between behavioral deficits and oxidative stress generation in the Pb-exposed rats. Interestingly, sesamin treatment mitigated anxio-depressive-like behaviors, ameliorated object recognition memory impairment, and modulated oxidative-antioxidative status in the rats exposed to Pb. The results suggest that the anti-oxidative properties of sesamin may be one of the underlying mechanisms behind its beneficial effect in ameliorating behavioral deficits associated with Pb exposure.

Lignans as multi-targeted natural products in neurodegenerative diseases and depression: Recent perspectives

As the global population ages, the treatment of neurodegenerative diseases is becoming more and more important. There is an urgent need to discover novel drugs that are effective in treating neurological diseases. In recent years, natural products and their biological activities have gained widespread attention. Lignans are a class of metabolites extensively present in Chinese herbal medicine and possess good pharmacological effects. Latest studies have demonstrated their neuroprotective pharmacological activity in preventing acute/chronic neurodegenerative diseases and depression. In this review, the pharmacological effects of these disorders, the pharmacokinetics, safety, and clinical trials of lignans were summarized according to the scientific literature. These results proved that lignans mainly exert antioxidant and anti-inflammatory activities. Anti-apoptosis, regulation of nervous system functions, and modulation of synaptic signals are also potential effects. Despite the substantial evidence of the neuroprotective potential of lignans, it is not sufficient to support their use in the clinical management. Our study suggests that lignans can be used as prospective agents for the treatment of neurodegenerative diseases and depression, with a view to informing their further development and utilization.

Frizzled 6 mutation regulates reserpine-induced depression-like behavior and Wnt signaling pathway in mice

BACKGROUND

Frizzled 6 (Fzd6) is involved in the development of various disorders; however, its role in the etiology of depression remains unclear. We aimed to determine the potential regulatory mechanisms of Fzd6 as a Wnt receptor in depression.

METHODS

Mice were divided into four groups: wild-type control (Fzd6WT-control), Fzd6 mutant control (Fzd6Q152E-control), wild-type reserpine (Fzd6WT-reserpine), and Fzd6 mutant reserpine (Fzd6Q152E-reserpine). Reserpine (0.5 mg/kg) was injected intraperitoneally for 10 days. Four behavioral experiments were performed to assess the effects of Fzd6Q152E on depression-like behaviors in the reserpine-treated mice. Blood samples were collected for an enzyme-linked immunosorbent assay (ELISA). Gene expression in the hippocampus was quantified using quantitative real-time polymerase chain reaction (qRT-PCR), and protein expression levels in the hippocampus were identified using western blotting.

RESULTS

The Fzd6 mutation affected reserpine-induced depression-like behavioral changes in mice. ELISA revealed significantly reduced serum levels of 5-hydroxytryptamine (5-HT), brain-derived neurotrophic factor (BDNF), and norepinephrine in both Fzd6Q152E-reserpine and Fzd6WT-reserpine mice, with a more pronounced decrease in Fzd6Q152E-reserpine mice, especially in norepinephrine expression. The qRT-PCR results showed significantly decreased Fzd6 expression in Fzd6Q152E-reserpine mice and altered expression of Dkk2, Gsk-3β, Lrp6, Wnt2, Wnt3, and Wnt3a in the Wnt pathway. Western blotting revealed decreased Fzd6 protein expression in Fzd6Q152E-control mice compared to Fzd6WT-control mice, whereas Fzd6 protein expression was restored in Fzd6Q152E-reserpine mice, and Gsk-3β expression was significantly changed.

CONCLUSION

Fzd6 potentially influences reserpine-induced depressive behavioral changes and serum depressive factor alterations and modulates the expression of the Wnt signaling pathway in the hippocampus of depressed mice.

Antidepressant-like Effects of Representative Types of Food and Their Possible Mechanisms

Depression is a mental disorder characterized by low mood, lack of motivation, negative cognitive outlook, and sleep problems. Suicide may occur in severe cases, although suicidal thoughts are not seen in all cases. Globally, an estimated 350 million individuals grapple with depression, as reported by the World Health Organization. At present, drug and psychological treatments are the main treatments, but they produce insufficient responses in many patients and fail to work at all in many others. Consequently, treating depression has long been an important topic in society. Given the escalating prevalence of depression, a comprehensive strategy for managing its symptoms and impacts has garnered significant attention. In this context, nutritional psychiatry emerges as a promising avenue. Extensive research has underscored the potential benefits of a well-rounded diet rich in fruits, vegetables, fish, and meat in alleviating depressive symptoms. However, the intricate mechanisms linking dietary interventions to brain function alterations remain largely unexplored. This review delves into the intricate relationship between dietary patterns and depression, while exploring the plausible mechanisms underlying the impact of dietary interventions on depression management. As we endeavor to unveil the pathways through which nutrition influences mental well-being, a holistic perspective that encompasses multidisciplinary strategies gains prominence, potentially reshaping how we approach and address depression.

The Effects of Chronic Unpredictable Mild Stress and Semi-Pure Diets on the Brain, Gut and Adrenal Medulla in C57BL6 Mice

Chronic stress is known to perturb serotonergic regulation in the brain, leading to mood, learning and memory impairments and increasing the risk of developing mood disorders. The influence of the gut microbiota on serotonergic regulation in the brain has received increased attention recently, justifying the investigation of the role of diet on the gut and the brain in mood disorders. Here, using a 4-week chronic unpredictable mild stress (CUMS) model in mice, we aimed to investigate the effects of a high-fat high-glycaemic index (HFD) and high-fibre fruit & vegetable "superfood" (SUP) modifications of a semi-pure AIN93M diet on behaviour, serotonin synthesis and metabolism pathway regulation in the brain and the gut, as well as the gut microbiota and the peripheral adrenal medullary system. CUMS induced anxiety-like behaviour, dysregulated the tryptophan and serotonin metabolic pathways in the hippocampus, prefrontal cortex, and colon, and altered the composition of the gut microbiota. CUMS reduced the catecholamine synthetic capacity of the adrenal glands. Differential effects were found in these parameters in the HFD and SUP diet. Thus, dietary modifications may profoundly affect the multiple dynamic systems involved in mood disorders.

Rosiglitazone attenuates amyloid beta and glial fibrillary acidic protein in the hippocampus and neuroinflammation associated learning and memory impairments in rats

OBJECTIVE

The aim of the current study was to investigate the beneficial effects of rosiglitazone (Rosi) on amyloid beta(Aβ) and glial fibrillary acidic protein (GFAP) in the hippocampus and neuroinflammation-associated learning and memory impairments in rats.

MATERIALS AND METHODS

The rats were grouped and treated as follows: (1) Control in which saline and vehicle were administered instead of LPS and Rosi respectively. (2) Lipopolysaccharide (LPS) group in which LPS was dissolved in saline and injected (1 mg/kg) intraperitoneally. Vehicle was administered instead of Rosi in this group. (3-5) LPS+ Rosi 1, LPS+ Rosi 3, and LPS+ Rosi 5 groups in them 1, 3, or 5 mg/kg of Rosi respectively was administered 30 min before LPS. The treatments were done for two weeks. In the first week, Rosi or its vehicle was injected 30 min before LPS. In the second week, the treatments were the same as the first week and behavioral tests were also carried out in the second week. The hippocampal tissues were finally detached for biochemical assessment.

RESULTS

The results showed that Rosi reversed increased levels of Aβ, GFAP, interleukin (IL)- 6, tumor necrosis factor-α (TNF-α), nitric oxide (NO) metabolites, and malondialdehyde (MDA) due to LPS injection. Rosi also reversed attenuating effects of LPS on IL-10 and thiol concentration and activities of catalase (CAT) and superoxide dismutase (SOD). In the Morris water maze test, the LPS group had a longer latency to find the platform while spent a shorter time spent in the target quadrant in the probe trial than the control group. In the passive avoidance test, the animals of the LPS group had a shorter delay to enter the dark chamber than the animals of the control group. Treatment with Rosi reversed these parameters.

CONCLUSION

The findings showed Rosi attenuated Aβ, GFAP, and oxidative stress in the hippocampus and neuroinflammation-associated learning and memory impairments in rats.

Effects of sesame (Sesamum indicum L.) and bioactive compounds (sesamin and sesamolin) on inflammation and atherosclerosis: A review

Inflammation, oxidative stress, obesity, infection, hyperlipidemia, hypertension, and diabetes are the main causes of atherosclerosis, which in the long term lead to hardening of the arteries. In the current study, we reviewed recent findings of the mechanism of sesame and its active compounds of sesamin and sesamolin regulates on atherosclerosis. Sesame can decrease the lipid peroxidation and affect the enzymes, which control the balance of oxidative status in the body. Besides modulating the inflammatory cytokines, sesame regulates the main mediators of the signaling pathways in the process of inflammation, such as prostaglandin E2 (PGE2), nuclear factor kappa light-chain enhancer of activated B cells (NF-kB) and peroxisome proliferator-activated receptor gamma (PPAR-γ). Sesame decreases the growth of different pathogens. It fights against obesity and helps to reduce weight, body mass index (BMI), waist circumference, and lipid count of serum and liver. In addition to lowering fasting blood sugar (FBS), it decreases the hemoglobin A1c (HbA1c) and glucose levels and improves insulin function. With high content of linoleic acid, α-linolenic acid, and total polyunsaturated fatty acid (PUFA), sesame efficiently controls the blood plasma lipids and changes the lipid profile. In the case of hypertension, it maintains the health of endothelium through multiple mechanisms and conserves the response of the arteries to vasodilation. PUFA in sesame suppresses blood clotting and fibrinogen activity. All the mentioned properties combat atherosclerosis and hardening of blood vessels, which are detailed in the present review for sesame.

Soy protein increases cognitive level in mice by modifying hippocampal nerve growth, oxidative stress, and intestinal microbiota

BACKGROUND

Three kinds of diet containing chicken protein isolate (CPI), bovine milk protein isolate (BMPI), and soy protein isolate (SPI), respectively, were designed to investigate the influences of proteins on cognitive levels and related mechanisms in mice.

RESULTS

A Morris water maze (MWM) test showed that the SPI group had a higher cognitive level than the BMPI group. Immunohistochemical staining and chemical analysis of the hippocampus showed that the SPI group had higher synaptophysin expression, doublecortin-positive cell proportion, superoxide dismutase activity, and lower malondialdehyde content compared with the BMPI group. The same parameters in the CPI group were between those of the BMPI and SPI groups. Microbiome sequencing indicated that the three groups differed significantly at the phylum, genus, and species levels, with higher microbial alpha diversity in the CPI and SPI groups. The association of intestinal microbiota with cognitive improvement was also assessed. The present study suggests that soy protein may increase cognitive function by the gut-brain axis.

CONCLUSION

In contrast with CPI and BMPI, SPI had a better effect on improving the cognitive level in mice, which was achieved through the regulation of hippocampal neural growth, oxidative stress, and intestinal microbiota. © 2022 Society of Chemical Industry.

Areca catechu L. ameliorates chronic unpredictable mild stress-induced depression behavior in rats by the promotion of the BDNF signaling pathway

OBJECTIVES

In this study, we have investigated the anti-depressant effects of the fruit Areca catechu L. (ACL) and elucidated its potential underlying mechanism using a rat model of chronic unpredictable mild stress (CUMS).

METHODS

CUMS was induced in rats to establish a depression animal model for 28 days. According to the baseline sucrose preference, the male rats were divided into 6 different groups. They were treated with paroxetine hydrochloride, ACL, and water once a day until the behavioral tests were performed. The levels of corticosterone (CORT), malondialdehyde (MDA), catalase (CAT), and total superoxide dismutase (T-SOD) in serum were detected using a commercial kit, and the concentrations of 5-hydroxytryptamine (5-HT) and dopamine (DA) monoamine neurotransmitters in the brain tissues were detected by liquid chromatography-tandem mass spectrometry. doublecortin (DCX) expression in the hippocampal dentate gyrus (DG) was determined by immunofluorescence, and the relative abundance of brain-derived neurotrophic factor (BDNF), TrkB, PI3K, p-AKT/AKT, PSD-95, and p-GSK-3β/GSK-3β of brain tissues were assayed by western blot.

RESULTS

ACL markedly increased sucrose preference, decreased the immobility time, and shortened the feeding latency of CUMS-induced rats. CUMS induction resulted in marked changes in the contents of the monoamine neurotransmitters (5-HT and DA) in the hippocampus and cortex of brain tissues and the levels of CORT, MDA, CAT, and T-SOD in serum, whereas ACL administration alleviated these considerable changes. ACL promoted DCX expression in DG and increased the protein levels of BDNF, TrkB, PI3K, p-AKT/AKT, PSD-95, and p-GSK-3β/GSK-3β in the brains of CUMS-induced rats.

CONCLUSIONS

Our results indicated that ACL may improve depression-like behaviors in CUMS-induced rats by decreasing the hyperfunction and oxidative stress of the hypothalamic-pituitary-adrenal axis, stimulating hippocampal neurogenesis, and activating the BDNF signaling pathway.

Lignan-Rich Sesame (Sesamum indicum L.) Cultivar Exhibits In Vitro Anti-Cholinesterase Activity, Anti-Neurotoxicity in Amyloid-β Induced SH-SY5Y Cells, and Produces an In Vivo Nootropic Effect in Scopolamine-Induced Memory Impaired Mice

Alzheimer's disease, a major cause of dementia, is characterized by impaired cholinergic function, increased oxidative stress, and amyloid cascade induction. Sesame lignans have attracted considerable attention owing to their beneficial effects on brain health. This study investigated the neuroprotective potential of lignan-rich sesame cultivars. Among the 10 sesame varieties studied, Milyang 74 (M74) extracts exhibited the highest total lignan content (17.71 mg/g) and in vitro acetylcholinesterase (AChE) inhibitory activity (66.17%, 0.4 mg/mL). M74 extracts were the most effective in improving cell viability and inhibiting reactive oxygen species (ROS) and malondialdehyde (MDA) generation in amyloid-β_25-35 fragment-treated SH-SY5Y cells. Thus, M74 was used to evaluate the nootropic effects of sesame extracts and oil on scopolamine (2 mg/kg)-induced memory impairment in mice compared to the control cultivar (Goenback). Pretreatment with the M74 extract (250 and 500 mg/kg) and oil (1 and 2 mL/kg) effectively improved memory disorder in mice (demonstrated by the passive avoidance test), inhibited AChE, and enhanced acetylcholine (Ach) levels. Moreover, immunohistochemistry and Western blot results showed that the M74 extract and oil reversed the scopolamine-induced increase in APP, BACE-1, and presenilin expression levels in the amyloid cascade and decreased BDNF and NGF expression levels in neuronal regeneration.

SARS-CoV-2 envelope protein triggers depression-like behaviors and dysosmia via TLR2-mediated neuroinflammation in mice

BACKGROUND

Depression and dysosmia have been regarded as primary neurological symptoms in COVID-19 patients, the mechanism of which remains unclear. Current studies have demonstrated that the SARS-CoV-2 envelope (E) protein is a pro-inflammatory factor sensed by Toll-like receptor 2 (TLR2), suggesting the pathological feature of E protein is independent of viral infection. In this study, we aim to ascertain the role of E protein in depression, dysosmia and associated neuroinflammation in the central nervous system (CNS).

METHODS

Depression-like behaviors and olfactory function were observed in both female and male mice receiving intracisternal injection of E protein. Immunohistochemistry was applied in conjunction with RT-PCR to evaluate glial activation, blood-brain barrier status and mediators synthesis in the cortex, hippocampus and olfactory bulb. TLR2 was pharmacologically blocked to determine its role in E protein-related depression-like behaviors and dysosmia in mice.

RESULTS

Intracisternal injection of E protein evoked depression-like behaviors and dysosmia in both female and male mice. Immunohistochemistry suggested that the E protein upregulated IBA1 and GFAP in the cortex, hippocampus and olfactory bulb, while ZO-1 was downregulated. Moreover, IL-1β, TNF-α, IL-6, CCL2, MMP2 and CSF1 were upregulated in both cortex and hippocampus, whereas IL-1β, IL-6 and CCL2 were upregulated in the olfactory bulb. Furtherly, inhibiting microglia, rather than astrocytes, alleviated depression-like behaviors and dysosmia induced by E protein. Finally, RT-PCR and immunohistochemistry suggested that TLR2 was upregulated in the cortex, hippocampus and olfactory bulb, the blocking of which mitigated depression-like behaviors and dysosmia induced by E protein.

CONCLUSIONS

Our study demonstrates that envelope protein could directly induce depression-like behaviors, dysosmia, and obvious neuroinflammation in CNS. TLR2 mediated depression-like behaviors and dysosmia induced by envelope protein, which could serve as a promising therapeutic target for neurological manifestation in COVID-19 patients.

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.

Memory impairments in rodent depression models: A link with depression theories

More than 80% of depressed patients struggle with learning new tasks, remembering positive events, or concentrating on a single topic. These neurocognitive deficits accompanying depression may be linked to functional and structural changes in the prefrontal cortex and hippocampus. However, their mechanisms are not yet completely understood. We conducted a narrative review of articles regarding animal studies to assess the state of knowledge. First, we argue the contribution of changes in neurotransmitters and hormone levels in the pathomechanism of cognitive dysfunction in animal depression models. Then, we used numerous neuroinflammation studies to explore its possible implication in cognitive decline. Encouragingly, we also observed a positive correlation between increased oxidative stress and a depressive-like state with concomitant memory deficits. Finally, we discuss the undeniable role of neurotrophin deficits in developing cognitive decline in animal models of depression. This review reveals the complexity of depression-related memory impairments and highlights the potential clinical importance of gathered findings for developing more reliable animal models and designing novel antidepressants with procognitive properties.

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms

Cognitive, mood and sleep disorders are common and intractable disorders of the central nervous system, causing great inconvenience to the lives of those affected. The gut-brain axis plays a vital role in studying neurological disorders such as neurodegenerative diseases by acting as a channel for a bidirectional information exchange between the gut microbiota and the nervous system. Dietary polyphenols have received widespread attention because of their excellent biological activity and their wide range of sources, structural diversity and low toxicity. Dietary intervention through the increased intake of dietary polyphenols is an emerging strategy for improving circadian rhythms and treating metabolic disorders. Dietary polyphenols have been shown to play an essential role in regulating intestinal flora, mainly by maintaining the balance of the intestinal flora and enhancing host immunity, thereby suppressing neurodegenerative pathologies. This paper reviewed the bidirectional interactions between the gut microbiota and the brain and their effects on the central nervous system, focusing on dietary polyphenols that regulate circadian rhythms and maintain the health of the central nervous system through the gut-brain axis.

Could peripheral 5-HT level be used as a biomarker for depression diagnosis and treatment? A narrative minireview

The serotonin hypothesis of depression is still influential, but the relationship between peripheral 5-HT levels and depression is still unknown. This review aimed to verify whether peripheral 5-HT levels could be used as a biomarker for depression diagnosis and treatment. PubMed and EMBASE were searched using terms appropriate to the area of research. Articles from 1957 to 2022 in the following terms were identified: depression, 5-HT, serotonin and peripheral (serum, plasma, blood platelets). 33 studies were included: seven clinical trials about periphery 5-HT levels in depressive patients compared to normal subjects, 15 clinical trials about changes of peripheral 5-HT levels in patients with depression after drug treatment and 11 animal experiments about peripheral 5-HT levels in animal models of depression. Peripheral 5-HT levels presented three different outcomes before and after antidepressant treatments: increased, decreased and no significant change. In conclusion, changes in peripheral 5-HT levels did not show consistent results among these studies. Peripheral 5-HT level could not be used as a biomarker both for depression diagnosis and for antidepressant efficacy evaluation.

Ameliorative effect of sesame oil on experimentally induced polycystic ovary syndrome: A cross-link between XBP-1/PPAR-1, regulatory proteins for lipogenesis/steroids

Polycystic ovary syndrome (PCOS) is a mixed endocrine/metabolic/reproductive disorder in women of reproductive age. Sesame oil (SO) contains sesame lignans & vitamin E with broad-spectrum antioxidant and anti-inflammatory effects. This study investigates the ameliorative effect of SO on experimentally induced PCOS and elucidates the possible molecular mechanisms with a deeper focus on the different signaling pathways involved. The study was carried out on 28 nonpregnant female Wister albino rats that were divided into four equal groups; Group I (control group) received oral 0.5% wt/vol carboxymethyl cellulose daily. Group II (SO group): orally administered SO (2 mL/kg body wt./day) for 21 days. Group III (PCOS group) received letrozole daily, 1 mg/kg, for 21 days. Group IV (PCOS + SO group): concomitantly administered letrozole and SO for 21 days. The serum hormonal and metabolic panel and the homogenate ATF-1, StAR, MAPK, PKA, and PI3K levels of the ovarian tissue were calorimetrically evaluated. However, endoplasmic reticulum (ER) stress was evaluated by ovarian XBP1 and PPAR-γ messenger RNA expression level using the qRT-PCR technique. Ovarian COX-2 was detected immunohistochemically. The results suggest that SO-treated PCOS rats showed a significantly improved hormonal, metabolic panel, inflammatory, and ER stress status with concomitant decreases in ATF-1, StAR, MAPK, PKA, and PI3K in ovarian rats compared to the correspondent values in PCOS without treatment. CONCLUSIONS: The protective effects of SO against PCOS are triggered by ameliorating regulatory proteins of ER stress, lipogenesis, and steroidogenesis through the PI3K/PKA and MAPK/ERK2 signaling cascades. SIGNIFICANCE STATEMENT: Polycystic ovary syndrome (PCOS) is the most common mixed endocrine-metabolic dysfunction among women within the reproductive period, with an estimated prevalence of 5%-26% worldwide. Doctors traditionally recommend metformin for PCOS patients. However, metformin is known to be associated with significant adverse effects and contraindications. This work aimed at shedding light on the ameliorative effect of sesame oil (SO), natural polyunsaturated fatty acids-rich oil, on the induced PCOS model. SO proved to have a marvelous effect on the metabolic and endocrine derangements in the PCOS rat model. We hoped to provide a valuable alternative treatment for PCOS patients to avoid the side effects of metformin and to help PCOS patients for whom metformin is contraindicated.

Effects of sesamin on Aβ1-42-induced oxidative stress and LTP impairment in a rat model of Alzheimer's disease

The present study examined the protective effect of sesamin (Ses) on β-amyloid (Aβ)-induced long-term potentiation (LTP) impairment at the PP-DG synapses in male rats. Wistar rats were randomly assigned to seven groups: control, sham, Aβ; ICV Aβ_1-42 microinjection, Ses, Aβ + Ses; first, ICV Aβ injections and then receiving Ses, Ses + Aβ: four weeks of pretreatment with Ses and then Aβ injection, and Ses + Aβ + Ses: pre (four weeks) and post (four weeks) treatment with Ses. Ses-treated groups received 30 mg/kg of Ses once a day by oral gavage for four weeks. After the treatment period, the animals were positioned in a stereotaxic device for surgery and field potential recording. The population spike (PS) amplitude and slope of excitatory postsynaptic potentials (EPSP) were evaluated in the DG region. Serum oxidative stress biomarkers (total oxidant status (TOS) and total antioxidant capacity (TAC)) were measured. Aβ impaired LTP induction at the PP-DG synapses evidenced by a decrease in EPSP slope and PS amplitude of LTP. In Aβ rats, Ses increased EPSP slope and PS amplitude of LTP in the DG granular cells. Also, an increase in TOS and a reduction in TAC caused by Aβ were significantly corrected by Ses. Ses could prevent Aβ-induced LTP impairment at the PP-DG synapses in male rats, which can be due to its preventive effects on oxidative stress.

Resequencing of 410 Sesame Accessions Identifies SINST1 as the Major Underlying Gene for Lignans Variation

Sesame is a promising oilseed crop that produces specific lignans of clinical importance. Hence, a molecular description of the regulatory mechanisms of lignan biosynthesis is essential for crop improvement. Here, we resequence 410 sesame accessions and identify 5.38 and 1.16 million SNPs (single nucleotide polymorphisms) and InDels, respectively. Population genomic analyses reveal that sesame has evolved a geographic pattern categorized into northern (NC), middle (MC), and southern (SC) groups, with potential origin in the southern region and subsequent introduction to the other regions. Selective sweeps analysis uncovers 120 and 75 significant selected genomic regions in MC and NC groups, respectively. By screening these genomic regions, we unveiled 184 common genes positively selected in these subpopulations for exploitation in sesame improvement. Genome-wide association study identifies 17 and 72 SNP loci for sesamin and sesamolin variation, respectively, and 11 candidate causative genes. The major pleiotropic SNP^C/A locus for lignans variation is located in the exon of the gene SiNST1. Further analyses revealed that this locus was positively selected in higher lignan content sesame accessions, and the "C" allele is favorable for a higher accumulation of lignans. Overexpression of SiNST1^C in sesame hairy roots significantly up-regulated the expression of SiMYB58, SiMYB209, SiMYB134, SiMYB276, and most of the monolignol biosynthetic genes. Consequently, the lignans content was significantly increased, and the lignin content was slightly increased. Our findings provide insights into lignans and lignin regulation in sesame and will facilitate molecular breeding of elite varieties and marker-traits association studies.

Fermented Perilla frutescens Ameliorates Depression-like Behavior in Sleep-Deprivation-Induced Stress Model

Excessive stress plays a critical role in the pathogenesis of mood disorders such as depression. Fermented natural products have recently attracted attention because of their health benefits. We evaluated the antidepressant-like efficacy of fermented Perilla frutescens (FPF), and its underlying mechanisms, in sleep deprivation (SD)-induced stress mice. SD-stressed mice revealed a remarkable increase in the immobility time in both forced swimming test and tail suspension test; this increase was ameliorated by treatment with FPF at doses of 100 and 150 mg/kg. FPF treatment also reduced the level of stress hormones such as corticosterone and adrenocorticotropic hormone. Additionally, FPF increased the levels of serotonin and dopamine which were significantly decreased in the brain tissues of SD-stressed mice. The increased expression of proinflammatory cytokines, such as TNF-α and IL1β, and the decreased expression of brain-derived neurotrophic factor (BDNF) in the stressed mice were significantly reversed by FPF treatment. Furthermore, FPF also increased phosphorylation of tropomyosin receptor kinase B (TrkB), extracellular regulated protein kinase (ERK), and cAMP response element binding protein (CREB). Among the six components isolated from FPF, protocatechuic acid and luteolin-7-O-glucuronide exhibited significant antidepressant-like effects, suggesting that they are major active components. These findings suggest that FPF has therapeutic potential for SD-induced stress, by correcting dysfunction of hypothalamic-pituitary-adrenal axis and modulating the BDNF/TrkB/ERK/CREB signaling pathway.

Effects of methionine intake on cognitive function in mild cognitive impairment patients and APP/PS1 Alzheimer's Disease model mice: Role of the cystathionine-β-synthase/H2S pathway

As a dietary intervention, methionine restriction (MR) has been reported to increase longevity and improve metabolism disorders. However, the effects of MR on alleviating neurodegenerative diseases such as Alzheimer's disease (AD) are largely unexplored. Here we sought to investigate the neuroprotective effects of low methionine intake in mild cognitive impairment (MCI) patients and APP/PS1 AD model mice, and to uncover the underlying mechanisms. In a cohort composed of 45 individuals diagnosed with MCI and 61 healthy controls without cognitive impairment, methionine intake was found to be positively associated with the increased risk of MCI, where no sex differences were observed. We further conducted a 16-week MR intervention (0.17% methionine, w/w) on APP/PS1 AD model mice. Although MR reduced Aβ accumulation in the brain of both male and female APP/PS1 mice, MR improved cognitive function only in male mice, as assessed by the Morris water maze test. Consistently, MR restored synapse ultrastructure and alleviated mitochondrial dysfunction by enhancing mitochondrial biogenesis in the brain of male APP/PS1 mice. Importantly, MR effectively balanced the redox status and activated cystathionine-β-synthase (CBS)/H₂S pathway in the brain of male APP/PS1 mice. Together, our study indicated that lower dietary methionine intake is associated with improved cognitive function, in which CBS/H₂S pathway plays an essential role. MR could be a promising nutritional intervention for preventing AD development.

Antioxidant, Anti-Inflammatory, Anti-Menopausal, and Anti-Cancer Effects of Lignans and Their Metabolites

Since chronic inflammation can be seen in severe, long-lasting diseases such as cancer, there is a high demand for effective methods to modulate inflammatory responses. Among many therapeutic candidates, lignans, absorbed from various plant sources, represent a type of phytoestrogen classified into secoisolariciresionol (Seco), pinoresinol (Pino), matairesinol (Mat), medioresinol (Med), sesamin (Ses), syringaresinol (Syr), and lariciresinol (Lari). Lignans consumed by humans can be further modified into END or ENL by the activities of gut microbiota. Lignans are known to exert antioxidant and anti-inflammatory activities, together with activity in estrogen receptor-dependent pathways. Lignans may have therapeutic potential for postmenopausal symptoms, including cardiovascular disease, osteoporosis, and psychological disorders. Moreover, the antitumor efficacy of lignans has been demonstrated in various cancer cell lines, including hormone-dependent breast cancer and prostate cancer, as well as colorectal cancer. Interestingly, the molecular mechanisms of lignans in these diseases involve the inhibition of inflammatory signals, including the nuclear factor (NF)-κB pathway. Therefore, we summarize the recent in vitro and in vivo studies evaluating the biological effects of various lignans, focusing on their values as effective anti-inflammatory agents.

Possible Effects and Mechanisms of Dietary Natural Products and Nutrients on Depression and Anxiety: A Narrative Review

Depression and anxiety are severe public health problems and have attracted more and more attention from researchers of food science and nutrition. Dietary natural products and nutrients, such as fish, coffee, tea, n-3 PUFA, lycopene, and dietary fiber, could play a vital role in the prevention and management of these diseases. The potential mechanisms of action mainly include inhibiting inflammation, ameliorating oxidative stress, modulating the microbiota-gut-brain axis, suppressing hypothalamic-pituitary-adrenal axis hyperactivity, and regulating the levels of monoamine neurotransmitters. In this narrative review, we summarize the most recent advancements regarding the effects of dietary natural products and nutrients on depression and anxiety, and their underlying mechanisms are discussed. We hope that this paper can provide a better understanding of the anti-depressive and anxiolytic action of dietary natural products, and that it is also helpful for developing dietary natural products for functional food, dietary supplements, or auxiliary agents for the prevention and management of these diseases.

Sesamol Attenuates Scopolamine-Induced Cholinergic Disorders, Neuroinflammation, and Cognitive Deficits in Mice

Alzheimer's disease (AD) is a neurodegenerative disease, characterized by memory loss and cognitive deficits accompanied by neuronal damage and cholinergic disorders. Sesamol, a lignan component in sesame oil, has been proven to have neuroprotective effects. This research aimed to investigate the preventive effects of sesamol on scopolamine (SCOP)-induced cholinergic disorders in C57BL/6 mice. The mice were pretreated with sesamol (100 mg/kg/d, p.o.) for 30 days. Behavioral tests indicated that sesamol supplement prevented SCOP-induced cognitive deficits. Sesamol enhanced the expression of neurotrophic factors and postsynaptic density (PSD) in SCOP-treated mice, reversing neuronal damage and synaptic dysfunction. Importantly, sesamol could balance the cholinergic system by suppressing the AChE activity and increasing the ChAT activity and M1 mAChR expression. Sesamol treatment also inhibited the expression of inflammatory factors and overactivation of microglia in SCOP-treated mice. Meanwhile, sesamol improved the antioxidant enzyme activity and suppressed oxidative stress in SCOP-treated mice and ameliorated the oxidized cellular status and mitochondrial dysfunction in SCOP-treated SH-SY5Y cells. In conclusion, these results indicated that sesamol attenuated SCOP-induced cognitive dysfunction via balancing the cholinergic system and reducing neuroinflammation and oxidative stress.

Food and nutraceutical functions of sesame oil: An underutilized crop for nutritional and health benefits

Sesame is the oldest oilseed crop known to humanity, though it contributes a small share in the global vegetable oil production. Sesame oil contains nutrients, including lignans, tocopherols, phytosterols, natural antioxidants, and bioactive compounds. It provides various health benefits such as anti-lipogenic, hypo-cholesterolemic, anti-degenerative, and neural health-promoting properties. Being an under-utilized minor crop, it has not received enough research attention for its food and nutraceutical potential. The sesame crop is a potential candidate to maintain the diversity of food oils and harness its benefits for improving human health. The present review will provide detailed research on sesame oil contents, health effects, nutraceuticals, oil quality, and value addition strategies. Also, the sesame oil nutritional quality was compared with other vegetable oils, highlighting the potential health and nutrition-related benefits. The way forward for further sesame improvement through value addition traits was also discussed.

Potential Mechanisms of Shu Gan Jie Yu Capsule in the Treatment of Mild to Moderate Depression Based on Systemic Pharmacology and Current Evidence

Background

Shu Gan Jie Yu (SGJY) capsule has a good effect on relieving depressive symptoms in China. However, the mechanism of action is still unclear. Therefore, systemic pharmacology and molecular docking approaches were used to clarify its corresponding antidepressant mechanisms.

Methods

Traditional Chinese Medicine Database and Analysis Platform (TCMSP), the Encyclopedia of Traditional Chinese Medicine (ETCM), and Swiss Target Prediction servers were used to screen and predict the bioactive components of the SGJY capsule and their antidepressive targets. Mild to moderate depression (MMD) related genes were obtained from GeneCards and DisGeNET databases. A network of bioactive components-therapeutic targets of the SGJY capsule was established by STRING 11.5 and Cytoscape 3.9.0 software. Gene function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed by utilizing Database for Annotation, Visualization, and Integrated Discovery (DAVID) platform. Active components were taken to dock with the hypothetical proteins by iGEMDOCK and SwissDock, and the docking details were visually displayed by UCSF Chimera software. Then, the related research literature of the SGJY capsule was reviewed, summarized, sorted, and analyzed, including experimental evidence and clinical experience.

Results

Seven active components and 45 intersection targets were included in the study. PPI network had genuinely uncovered the potential therapeutic targets, such as AKT1, HSP90AA1, ESR1, EGFR, and PTGS2. KEGG pathway analysis showed that the mechanism of the SGJY capsule on MMD was mainly involved in the PI3K-Akt signaling pathway.

Conclusions

In this study, we have successfully predicted the biochemically active constituents, potential therapeutic targets, and comprehensively predicted the related drug-gene interaction of the SGJY capsule for treating MMD and provided a basis for subsequent experiments.

Construction of Fzd6Q152E mice through CRISPR/Cas9 technology and their reproduction and identification

BACKGROUND

The CRISPR/Cas9 system is widely used for genome editing in human, rat and mouse cells. In this study, we established Fzd6 mutant mice using CRISPR/Cas9 technology, and obtained Fzd6 homozygous mutant (Fzd6^Q152E) mice through breeding. Fzd6 plays a role in depression, but there are few related reports. We used this model to investigate the mechanism of Fzd6 involved in depression, and build a solid foundation for subsequent in-depth studies.

METHODS AND RESULTS

The target of Fzd6 mutation was obtained by CRISPR/Cas9 technology and hippocampal tissue was collected for Nissl staining and histological analysis. Blood was collected for enzyme linked immunosorbent assay (ELISA); The gene expression of Fzd6 and the related genes expression in wnt pathway was quantified by quantitative real-time PCR (qRT-PCR), and then expression of Fzd6 and proteins in the Wnt pathway were identified by western blotting. ELISA results showed that the expression levels of brain derived neurotrophic factor (BDNF), 5-hydroxytryptamine (5-HT), and Noradrenaline (NE) in serum were significantly decreased in Fzd6^Q152E mice, whereas the mRNA expression of Lrp5, Lrp6, and Dkk2 is increased. The western blotting revealed that the expression of Fzd6 and Lrp6 is decreased, although the expression of Dkk2 and Gsk-3β increased.

CONCLUSION

Our study successfully established homozygous Fzd6 mutant mice model. The relationship between Fzd6-Wnt and depression was preliminarily clarified, which provides an ideal animal model for subsequent research on diseases induced by the Fzd6 mutation.

A Comprehensive Review on Distribution, Pharmacological Properties, and Mechanisms of Action of Sesamin

Sesamin is a kind of fat-soluble lignan extracted from sesame seeds or other plants. It has attracted more and more attention because of its extensive pharmacological activities. In this study, we systematically summarized the pharmacological activities of sesamin including antioxidant, anti-inflammatory, anticancer, protection of liver and kidney, prevention of diabetes, hypertension, and atherosclerosis. Studies focus on the abilities of sesamin to attenuate oxidative stress by reducing the levels of ROS and MDA, to inhibit the release of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, etc.), and to induce apoptosis and autophagy in cancer cells through a variety of signaling pathways such as NF-κB, JNK, p38 MAPK, PI3K/AKT, caspase-3, and p53. By inhibiting the production of ROS, sesamin can also enhance the biological activities of NO in blood vessels, improve endothelial dysfunction and hypertension, and change the process of atherosclerotic lesion formation. In line with this, the various pharmacological properties of sesamin have been discussed in this review so that we can have a deeper understanding of the pharmacological activities of sesamin and clear the future development direction of sesamin.

Noise Induced Depression-Like Behavior, Neuroinflammation and Synaptic Plasticity Impairments: The Protective Effects of Luteolin

Noise is a kind of sound that causes agitation and harms human health. Studies have shown that noise can lead to neuroinflammation, damage to synaptic plasticity and altered levels of neurotransmitters that may result in depression. The present study demonstrated that luteolin exerted antidepressant-like effects by improving neuroinflammation in a mouse model of noise-induced depression. Luteolin significantly alleviated noise-induced depression-like behavior. Notably, luteolin treatment not only remarkably ameliorated noise-induced inflammation in the hippocampus and prefrontal cortex, but also increased synapsin. Furthermore, luteolin treatment significantly increased the contents of serum 5-hydroxytryptamine and norepinephrine in noise-induced mice. In sum, luteolin exerts antidepressant effects indepression-like mice caused by noise, which can serve as a potential agent for the treatment of chronic noise-induced depression.

Sesamin protects against neurotoxicity via inhibition of microglial activation under high glucose circumstances through modulating p38 and JNK signaling pathways

Diabetes mellitus (DM), one of the principal causes of morbidity and mortality worldwide, is implicated in the progression of age-related neurodegenerative diseases (NDDs), in which microglial activation is a crucial mediator. Sesamin, a kind of phytochemical, shows inhibitory effects on microglial activation. The present study studied whether sesamin protects against neurotoxicity triggered by high glucose-induced microglial activation. We firstly demonstrated that high doses of glucose, which mimics hyperglycemia in DM, did induce the activation of murine BV2 microglial cells, increasing inflammatory responses such as the production of ROS or inflammatory mediators like IL-1β, TNF-⍺, and nitric oxide, through activation of p38 and JNK signaling pathways. Next, conditioned medium (CM) collected from high glucose-activated BV2 cell culture was used to show aggravated neurotoxicity in differentiated PC12 cells, indicating that high glucose-activated microglia could induce neurotoxicity. Interestingly, pretreatment of BV2 cells with sesamin diminished high glucose-induced microglia activation and inflammatory responses. Moreover, neurotoxicity in PC12 cells was found to be decreased in the group treated with CM from the sesamin-pretreated BV2 cell culture, suggesting sesamin inhibited microglial activation, thereby protecting neurons from activated microglia-mediated neurotoxicity. Thus, sesamin might be a potential compound to use in the prevention of diabetic-induced NDDs.

Sesamin: Insights into its protective effects against lead-induced learning and memory deficits in rats

BACKGROUND

Lead (Pb) is one of the most hazardous pollutants that induce a wide spectrum of neurological changes such as learning and memory deficits. Sesamin, a phytonutrient of the lignan class, exhibits anti-inflammatory, anti-apoptotic, and neuroprotective properties. The present study was designed to investigate the effects of sesamin against Pb-induced learning and memory deficits, disruption of hippocampal theta and gamma rhythms, inflammatory response, inhibition of blood δ-aminolevulinic acid dehydratase (δ-ALA-D) activity, Pb accumulation, and neuronal loss in rats.

METHODS

Sesamin treatment (30 mg/kg/day; P.O.) was started simultaneously with Pb acetate exposure (500 ppm in standard drinking water) in rats, and they continued for eight consecutive weeks.

RESULTS

The results showed that chronic exposure to Pb disrupted the learning and memory functions in both passive-avoidance and water-maze tests, which was accompanied by increase in spectral theta power and theta/gamma ratio, and a decrease in spectral gamma power in the hippocampus. Additionally, Pb exposure resulted in an enhanced tumor necrosis factor-alpha (TNF-α) content, decreased interleukin-10 (IL-10) production, inhibited blood δ-ALA-D activity, increased Pb accumulation, and neuronal loss of rats. In contrast, sesamin treatment improved all the above-mentioned Pb-induced pathological changes.

CONCLUSION

This data suggests that sesamin could improve Pb-induced learning and memory deficits, possibly through amelioration of hippocampal theta and gamma rhythms, modulation of inflammatory status, restoration of the blood δ-ALA-D activity, reduction of Pb accumulation in the blood and the brain tissues, and prevention of neuronal loss.

Sesamin Activates Skeletal Muscle FNDC5 Expression and Increases Irisin Secretion via the SIRT1 Signaling Pathway

Sesamin, a major lignin mainly found in sesame (Sesamum indicum) oil and sesame seeds, has been demonstrated to possess lipoclasis-promoting, antiobesity, and antidiabetic effects. Irisin is a newly discovered myokine that has attracted great interest as a key target to prevent/treat obesity and its related metabolic diseases. However, the effect and potential mechanism of sesamin on FNDC5/irisin are still vacant. In this study, we showed that sesamin treatment increased FNDC5/irisin activation and regulated SIRT1, PGC-1α, and p-SMAD3/SMAD3 expression in C2C12 cells. By using specific inhibitors and lentivirus in C2C12 cells, we found that the SIRT1/SMAD3 axis plays an important role in sesamin regulated FNDC5/irisin activation. We also found that sesamin treatment activated FNDC5 expression and regulated the SIRT1/SMAD3 signaling axis in mice's skeletal muscle. What is more, by the high-fat diet induced obese model, we further showed that sesamin improved the high-fat diet induced decrease in irisin production and secretion, which results in an improvement of body weight gain and skeletal muscle dysfunction. Our results suggested that sesamin could activate FNDC5 expression and stimulate irisin secretion through the SIRT1 pathway both in vitro and in vivo, which may provide a new strategy for preventing and improving irisin deficiency related diseases.

Alleviation of cognitive deficits via upregulation of chondroitin sulfate biosynthesis by lignan sesamin in a mouse model of neuroinflammation

Lignans are plant-derived compounds that act as partial estrogen agonists. Chondroitin sulfate proteoglycans (CSPGs) represent one of the major components of the extracellular matrix (ECM). Here we aimed to understand the role of sesamin (SES), a major lignan compound, in the biosynthesis and degradation of CSPGs in the mouse hippocampus because CSPGs play a key role in the regulation of cognitive functions through the promotion of adult neurogenesis. The expression of the pro-inflammatory cytokine interleukin-1β was decreased by SES administration in the hippocampus of lipopolysaccharide (LPS)-treated mice, a model of neuroinflammation-induced cognitive deficits. The expression of genes related to biosynthesis and degradation of CSPGs in the hippocampus of LPS-treated mice was both increased and decreased by SES administration. Further, the diffuse ECM labeling of CSPGs by Wisteria floribunda agglutinin (WFA) in the hippocampus of LPS-treated mice was increased by SES administration. The densities of neural stem cells, late transit-amplifying cells, and newborn-granule cells in the hippocampus of LPS-treated mice were also increased by SES administration. Moreover, SES-induced alterations in gene expression, WFA labeling, and adult neurogenesis in LPS-treated mice were more evident in the dorsal hippocampus (center of cognition) than in the ventral hippocampus (center of emotion). Neither LPS nor SES administration affected locomotor activity, anxiety-like behavior, and depression-related behavior. However, impairments in contextual memory and sensorimotor gating in LPS-treated mice were recovered by SES administration. Our results show that SES can promote adult hippocampal neurogenesis through the upregulation of CSPGs, which may alleviate cognitive deficits induced by neuroinflammation.

Melatonergic Receptors (Mt1/Mt2) as a Potential Additional Target of Novel Drugs for Depression

A complex pathogenesis involving several physiological systems is theorized to underline the development of depressive disorders. Depression is accompanied by circadian regulation disruption and interaction with the functioning of both central and peripheral oscillators. Many aspects of melatonin function unite these systems. The use of drugs for circadian rhythm disorders could inspire a potential treatment strategy for depression. Melatonin plays an essential role in the regulation of circadian rhythms. It exerts effect by activating two types of melatonin receptors, type 1A (MT1) and 1B (MT2). These are G-protein-coupled receptors, predominantly located in the central nervous system. MT1/MT2 agonists could be a useful treatment approach according to all three prevalent theories of the pathogenesis of depression involving either monoamines, synaptic remodeling, or immune/inflammatory events. MT1/MT2 receptors can be a potential target for novel antidepressants with impact on concentrations of neurotrophins or neurotransmitters, and reducing levels of pro-inflammatory cytokines. There is an interesting cross-talk mediated via the physical association of melatonin and serotonin receptors into functional heteromers. The antidepressive and neurogenetic effects of MT1/MT2 agonists can also be caused by the inhibition of the acid sphingomyelinase, leading to reduced ceramide, or increasing monoamine oxidase A levels in the hippocampus. Compounds targeting MT1 and MT2 receptors could have potential for new anti-depressants that may improve the quality of therapeutic interventions in treating depression and relieving symptoms. In particular, a combined effect on MT1 and/or MT2 receptors and neurotransmitter systems may be useful, since the normalization of the circadian rhythm through the melatonergic system will probably contribute to improved treatment. In this review, we discuss melatonergic receptors as a potential additional target for novel drugs for depression.

Microglia in depression: an overview of microglia in the pathogenesis and treatment of depression

Major depressive disorder is a highly debilitating psychiatric disorder involving the dysfunction of different cell types in the brain. Microglia are the predominant resident immune cells in the brain and exhibit a critical role in depression. Recent studies have suggested that depression can be regarded as a microglial disease. Microglia regulate inflammation, synaptic plasticity, and the formation of neural networks, all of which affect depression. In this review, we highlighted the role of microglia in the pathology of depression. First, we described microglial activation in animal models and clinically depressed patients. Second, we emphasized the possible mechanisms by which microglia recognize depression-associated stress and regulate conditions. Third, we described how antidepressants (clinical medicines and natural products) affect microglial activation. Thus, this review aimed to objectively analyze the role of microglia in depression and focus on potential antidepressants. These data suggested that regulation of microglial actions might be a novel therapeutic strategy to counteract the adverse effects of devastating mental disorders.

Bone marrow mononuclear cell transplant prevents rat depression and modulates inflammatory and neurogenic molecules

INTRODUCTION

Major depressive disorder is associated with chronic inflammation and deficient production of brain-derived neurotrophic factor (BDNF). Bone marrow mononuclear cell (BMMC) transplantation has an anti-inflammatory effect and has been proven effective in restoring non-depressive behavior. This study investigated whether BMMC transplantation can prevent the development of depression or anxiety in chronic mild stress (CMS), as well as its effect on inflammatory and neurogenic molecules.

METHOD

Three groups of animals were compared: BMMC-transplanted animals subjected to CMS for 45 days, CMS non-transplanted rats, and control animals. After the CMS period, the three groups underwent the following behavioral tests: sucrose preference test (SPT), eating-related depression test (ERDT), social avoidance test (SAT), social interaction test (SIT), and elevated plus maze test (EPMT). Transplanted cell tracking and measurement of the expression of high-mobility group box 1 (HMGB1), interleukin-1β (IL-1β), tumor necrosis factor (TNFα), and BDNF were performed on brain and spleen tissues.

RESULTS

BMMC transplantation prevented the effects of CMS in the SPT, ERDT, SAT, and SIT, while prevention was less pronounced in the EPMT. It was found to prevent increased HMGB-1 expression induced by CMS in the hippocampus and spleen, increase BDNF expression in both tissues, and prevent increased IL-1β expression in the hippocampus alone, while no effect of the transplant was observed in the TNFα expression. In addition, no transplanted cells were found in either the brain or spleen.

CONCLUSIONS

BMMC transplantation prevents the development of depression and anxiety-like behavior triggered by CMS. It could prevent increased HMGB-1 and IL-1β expression in the hippocampus and increased BDNF expression in the same tissue. Cell treatment represents a further perspective in the research and treatment of depression and possible mood disorders.

Microglia and HPA axis in depression: An overview of participation and relationship

Objectives: This narrative review article provides an overview on the involvement of microglia and the hypothalamic-pituitary-adrenal (HPA) axis in the pathophysiology of depression, as well investigates the mutual relationship between these two entities: how microglial activation can contribute to the dysregulation of the HPA axis, and vice versa.Methods: Relevant studies and reviews already published in the Pubmed electronic database involving the themes microglia, HPA axis and depression were used to meet the objectives.Results: Exposition to stressful events is considered a common factor in the mechanisms proposed to explain the depressive disorder. Stress can activate microglial cells, important immune components of the central nervous system (CNS). Moreover, another system involved in the physiological response to stressors is the hypothalamic-pituitary-adrenal (HPA) axis, the main stress response system responsible for the production of the glucocorticoid hormone (GC). Also, mediators released after microglial activation can stimulate the HPA axis, inducing production of GC. Likewise, high levels of GCs are also capable of activating microglia, generating a vicious cycle.Conclusion: Immune and neuroendocrine systems seems to work in a coordinated manner and that their dysregulation may be involved in the pathophysiology of depression since neuroinflammation and hypercortisolism are often observed in this disorder.

Electroacupuncture ameliorates neuroinflammation in animal models

Background:

Neuroinflammation refers to a wide range of immune responses occurring in the brain or spinal cord. It is closely related to a variety of neurodegenerative diseases, for which it potentially represents a new direction for treatment. Electroacupuncture (EA) is one method of acupuncture treatment, which can be used as an adjuvant therapy for many diseases. This review focuses on molecular mechanisms of EA in the reduction of neuroinflammation, summarizes relevant basic research and outlines future directions for investigation.

Findings:

A growing body of basic research has shown that EA can ameliorate neuroinflammation centrally (in animal models of ischemic stroke, Alzheimer’s disease, traumatic brain injury, spinal cord injury, Parkinson’s disease and vascular dementia) and peripherally (e.g. after a surgical insult or injection of lipopolysaccharide) and that its effects involve different molecular mechanisms, including activation of the α7 nicotinic acetylcholine receptor signaling pathway and P2 type purinergic receptors, inhibition of nuclear factor κB, and mitigation of damage secondary to oxidative stress and NOD-like receptor protein 3 inflammasome activation.

Conclusions:

EA is capable of regulating multiple cell signal transduction pathways to alleviate neuroinflammation in animal models. Although the findings of animal studies are encouraging, further prospective clinical trials are needed to verify the efficacy of EA for the treatment of neuroinflammation.

Pharmacological Properties to Pharmacological Insight of Sesamin in Breast Cancer Treatment: A Literature-Based Review Study

The use of dietary phytochemical rather than conventional therapies to treat numerous cancers is now a well-known approach in medical science. Easily available and less toxic dietary phytochemicals present in plants should be introduced in the list of phytochemical-based treatment areas. Sesamin, a natural phytochemical, may be a promising chemopreventive agent aiming to manage breast cancer. In this study, we discussed the pharmacological properties of sesamin that determine its therapeutics opportunity to be used in breast cancer treatment and other diseases. Sesamin is available in medicinal plants, especially in Sesamum indicum, and is easily metabolized by the liver. To better understand the antibreast cancer consequence of sesamin, we postulate some putative pathways related to the antibreast cancer mechanism: (1) regulation of estrogen receptor (ER-α and ER-β) activities, (2) suppressing programmed death-ligand 1 (PD-L1) overexpression, (3) growth factor receptor inhibition, and (4) some tyrosine kinase pathways. Targeting these pathways, sesamin can modulate cell proliferation, cell cycle arrest, cell growth and viability, metastasis, angiogenesis, apoptosis, and oncogene inactivation in various in vitro and animal models. Although the actual tumor intrinsic signaling mechanism targeted by sesamin in cancer treatment is still unknown, this review summarized that this phytoestrogen suppressed NF-κB, STAT, MAPK, and PIK/AKT signaling pathways and activated some tumor suppressor protein in numerous breast cancer models. Cotreatment with γ-tocotrienol, conventional drugs, and several drug carriers systems increased the anticancer potentiality of sesamin. Furthermore, sesamin exhibited promising pharmacokinetics properties with less toxicity in the bodies. Overall, the shreds of evidence highlight that sesamin can be a potent candidate to design drugs against breast cancer. So, like other phytochemicals, sesamin can be consumed for better therapeutic advantages due to having the ability to target a plethora of molecular pathways until clinically trialed standard drugs are not available in pharma markets.

Links Between Gut Dysbiosis and Neurotransmitter Disturbance in Chronic Restraint Stress-Induced Depressive Behaviours: the Role of Inflammation

Accumulating evidence has shown that inflammation, the gut microbiota, and neurotransmitters are closely associated with the pathophysiology of depression. However, the links between the gut microbiota and neurotransmitter metabolism remain poorly understood. The present study aimed to investigate the neuroinflammatory reactions in chronic restraint stress (CRS)-induced depression and to delineate the potential links between the gut microbiota and neurotransmitter metabolism. C57BL/6 mice were subjected to chronic restraint stress for 5 weeks, followed by behavioural tests (the sucrose preference test, forced swim test, open field test, and elevated plus maze) and analysis. The results showed that CRS significantly increased interleukin-1 beta (IL-1β), interleukin-2 (IL-2), interleukin-6 (IL-6), and tumour necrosis factor α (TNFα) levels and decreased brain-derived neurotrophic factor (BDNF) expression, accompanied by the activation of IkappaB-alpha-phosphorylation-nuclear factor kappa-B (IκBα-p-NF-κB) signalling in the mouse hippocampus. In addition, the neurotransmitter metabolomics results showed that CRS resulted in decreased levels of plasma 5-hydroxytryptamine (5-HT), dopamine (DA), and noradrenaline (NE) and their corresponding metabolites, and gut microbiota faecal metabolites with the 16S rRNA gene sequencing indicated that CRS caused marked microbiota dysbiosis in mice, with a significant increase in Helicobacter, Lactobacillus, and Oscillibacter and a decrease in Parabacteroides, Ruminococcus, and Prevotella. Notably, CRS-induced depressive behaviours and the disturbance of neurotransmitter metabolism and microbiota dysbiosis can be substantially restored by dexamethasone (DXMS) administration. Furthermore, a Pearson heatmap focusing on correlations between the microbiota, behaviours, and neurotransmitters showed that Helicobacter, Lactobacillus, and Oscillibacter were positively correlated with depressive behaviours but were negatively correlated with neurotransmitter metabolism, and Parabacteroides and Ruminococcus were negatively correlated with depressive behaviours but were positively correlated with neurotransmitter metabolism. Taken together, the results suggest that inflammation is involved in microbiota dysbiosis and the disturbance of neurotransmitter metabolism in CRS-induced depressive changes, and the delineation of the potential links between the microbiota and neurotransmitter metabolism will provide novel strategies for depression treatment.

Sesamol Attenuates Amyloid Peptide Accumulation and Cognitive Deficits in APP/PS1 Mice: The Mediating Role of the Gut-Brain Axis

Alzheimer's disease (AD), a neurodegenerative disease, is the leading cause of dementia. Sesamol is a lignan extracted from sesame oil and has been found to exert neuroprotective effects. The present study aimed to investigate the neuroprotective effects of sesamol on APPswe/PS1dE9 transgenic AD mice. The AD mice were fed with a diet supplemented with sesamol (0.075 w/w %). Sesamol treatment improved spatial memory and learning ability in AD mice, improved neuronal damage, and decreased Aβ accumulation. Sesamol protected the synaptic ultrastructure and inhibited neuroinflammatory responses in the brain of AD mice. Sesamol also significantly inhibited the overactivated microglia and reduced the overexpression of TNF-α and IL-1β in the brain of AD mice. Notably, sesamol reshaped gut microbiota by significantly decreasing the relative abundance of Helicobacter hepaticus, Clostridium, and Bacillaceae, enhancing the relative abundance of Rikenellaceae and Bifidobacterium in AD mice. It has been found that sesamol protected the gut barrier integrity and prevented the LPS leakage into the serum. Importantly, sesamol remarkably enhanced the content of SCFAs, including acetate, propionate, isobutyrate, butyrate, and valerate, in AD mice. Correlation analysis indicated that there was a strong correlation between the levels of SCFAs and cognitive functions. These results demonstrated that sesamol attenuated AD-related cognitive dysfunction and neuroinflammatory responses, which could be partly explained by its role in mediating the gut microbe-SCFA-brain axis. Thus, sesamol is a promising nutritional intervention strategy to prevent AD via the microbiota-gut-brain axis.

COVID-19, cytokines, inflammation, and spices: How are they related?

BACKGROUND

Cytokine storm is the exaggerated immune response often observed in viral infections. It is also intimately linked with the progression of COVID-19 disease as well as associated complications and mortality. Therefore, targeting the cytokine storm might help in reducing COVID-19-associated health complications. The number of COVID-19 associated deaths (as of January 15, 2021; https://www.worldometers.info/coronavirus/) in the USA is high (1199/million) as compared to countries like India (110/million). Although the reason behind this is not clear, spices may have some role in explaining this difference. Spices and herbs are used in different traditional medicines, especially in countries such as India to treat various chronic diseases due to their potent antioxidant and anti-inflammatory properties.

AIM

To evaluate the literature available on the anti-inflammatory properties of spices which might prove beneficial in the prevention and treatment of COVID-19 associated cytokine storm.

METHOD

A detailed literature search has been conducted on PubMed for collecting information pertaining to the COVID-19; the history, origin, key structural features, and mechanism of infection of SARS-CoV-2; the repurposed drugs in use for the management of COVID-19, and the anti-inflammatory role of spices to combat COVID-19 associated cytokine storm.

KEY FINDINGS

The literature search resulted in numerous in vitro, in vivo and clinical trials that have reported the potency of spices to exert anti-inflammatory effects by regulating crucial molecular targets for inflammation.

SIGNIFICANCE

As spices are derived from Mother Nature and are inexpensive, they are relatively safer to consume. Therefore, their anti-inflammatory property can be exploited to combat the cytokine storm in COVID-19 patients. This review thus focuses on the current knowledge on the role of spices for the treatment of COVID-19 through suppression of inflammation-linked cytokine storm.