Effects of curcumin on learning and memory deficits, BDNF, and ERK protein expression in rats exposed to chronic unpredictable stress

Nutritional practices to manage menstrual cycle related symptoms: a systematic review

Certain nutritional practices may reduce menstrual-related symptoms, but there is no current consensus on what foods/supplements are sufficiently evidenced to warrant promotion to reduce menstrual symptoms of naturally menstruating individuals. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Two online databases were searched for published experimental studies that investigated the effects of foods/supplements on menstrual-related symptoms in eumenorrhoeic women. Extracted data and study characteristics were tabulated and grouped on the basis of food/supplement intervention and dosage compared with UK dietary reference values (DRV) and safe upper limits. In total, twenty-eight studies and twenty-one different foods/supplement interventions were included in the review. None of the studies reported a negative effect on symptoms, twenty-three reported a positive effect and five had no effect. Eighteen different ways of measuring menstrual-related symptoms were described across the studies. The results indicate a lack of consistency in studies to confidently provide information to eumenorrheic, naturally menstruating women regarding the use of foods/supplements to reduce menstrual symptoms. Determination of menstrual-related symptoms varied along with dose and duration of food or supplements provided. These data provide some evidence for the use of vitamin D, calcium, zinc and curcumin to reduce menstrual-related symptoms of non-hormonal contraceptive users, on an individual basis; however, further investigation is required prior to implementation with a focus on robust protocols to determine and measure changes in menstrual symptoms, with interventions adhering to DRV and safe upper limits.

Curcumin: A Golden Approach to Healthy Aging: A Systematic Review of the Evidence

Aging-related disorders pose significant challenges due to their complex interplay of physiological and metabolic factors, including inflammation, oxidative stress, and mitochondrial dysfunction. Curcumin, a natural compound with potent antioxidant and anti-inflammatory properties, has emerged as a promising candidate for mitigating these age-related processes. However, gaps in understanding the precise mechanisms of curcumin's effects and the optimal dosages for different conditions necessitate further investigation. This systematic review synthesizes current evidence on curcumin's potential in addressing age-related disorders, emphasizing its impact on cognitive function, neurodegeneration, and muscle health in older adults. By evaluating the safety, efficacy, and mechanisms of action of curcumin supplementation, this review aims to provide insights into its therapeutic potential for promoting healthy aging. A systematic search across three databases using specific keywords yielded 2256 documents, leading to the selection of 15 clinical trials for synthesis. Here, we highlight the promising potential of curcumin as a multifaceted therapeutic agent in combating age-related disorders. The findings of this review suggest that curcumin could offer a natural and effective approach to enhancing the quality of life of aging individuals. Further research and well-designed clinical trials are essential to validate these findings and optimize the use of curcumin in personalized medicine approaches for age-related conditions.

Impact of social isolation on corticosterone release and recovery after stroke in aged rats: A behavioral and biochemical analysis

Social isolation (SI) after stroke reduces recovery. The aim of this study was to evaluate the effects of SI on corticosterone release and recovery after stroke in aged rats. A total of 64 male Wistar rats (aged 24 months) were used in the present study. All rats were housed in pairs for two weeks. After two weeks, rats were randomly assigned to one of four groups: (1) rats underwent sham surgery and kept socially isolated (control/social isolated (CO/SI) group); (2) rats underwent sham surgery and kept pair housed (control/pair housed (CO/PH) group); (3) rats underwent middle cerebral artery occlusion (MCAO) surgery and kept socially isolated (stroke/isolated (ST/SI) group); (4) rats underwent MCAO surgery and kept pair housed (stroke/pair housed (ST/PH)) group. Behaviors were assessed using the adhesive removal test, rotarod test and social interaction test at 1st, 7th, 14th and 21st days after stroke. Serum biochemical analysis was also performed on the behavioral testing days. Results showed THAT serum corticosterone and MDA levels in CO/PH group were significantly lower than CO/SI group. Serum BDNF levels in CO/PH group was significantly higher than CO/SI group. Serum corticosterone and MDA levels in ST/PH group were lower than ST/SI group. In ST/PH group, serum Total antioxidant capacity (TAC) and BDNF levels were significantly higher than ST/SI group. Biochemical analysis of certain regions of the brain (hippocampus, striatum and cerebral cortex) was performed on 21st day after stroke. In the hippocampus of CO/PH group, BDNF and TAC levels were significantly higher than CO/SI group. The hippocampal MDA level of CO/PH group were significantly lower than CO/SI group. BDNF and TAC levels in the hippocampus, striatum and cerebral cortex of ST/PH group were significantly higher and MDA level was significantly lower as compared with ST/SI group. Both ischemic groups showed sensorimotor recovery over a 21-day period, but recovery of ST/PH group was significantly greater than ST/SI group. Total social interaction time in ST/PH group was significantly longer than ST/SI group. Based on the results of this study, social interaction after stroke enhances histologic and sensorimotor recovery through reduction of HPA activity and corticosterone release, leading to increased TAC and BDNF levels.

Curcumin attenuates brain aging by reducing apoptosis and oxidative stress

Brain aging is a physiological event, and oxidative stress and apoptosis are involved in the natural aging process of the brain. Curcumin is a natural antioxidant with potent anti-aging and neuroprotective properties. Therefore, we investigated the protective effects of curcumin on brain apoptosis and oxidative stress, brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF) in aged rats. Old female Wistar rats were randomly divided into three groups (n = 7); as follows: (1) control; (2); saline and (3) curcumin (received 30 mg/kg of curcumin, 5 days/week for 8 weeks, intraperitoneally). Our results indicated that treatment with curcumin in aged rats attenuates brain lipid peroxidation, which was accompanied by a significant increase in the BDNF, VEGF, superoxide dismutase (SOD) activity, and anti-apoptotic protein BCl-2. No significant change in brain anti-apoptotic Bax protein levels was observed after curcumin treatment. The study indicates that curcumin could alleviate brain aging which may be due to attenuating oxidative stress, inhibiting apoptosis, and up-regulating SOD activity, which in turn enhances VEGF and BDNF. Therefore, curcumin has potential therapeutic value in the treatment of neurological apoptosis, neurogenesis, and angiogenesis changes caused by brain aging.

The Effects of Curcumin on Brain-Derived Neurotrophic Factor Expression in Neurodegenerative Disorders

Brain-Derived Neurotrophic Factor (BDNF) is a crucial molecule implicated in plastic modifications related to learning and memory. The expression of BDNF is highly regulated, which can lead to significant variability in BDNF levels in healthy subjects. Changes in BDNF expression might be associated with neuropsychiatric diseases, particularly in structures important for memory processes, including the hippocampus and parahippocampal areas. Curcumin is a natural polyphenolic compound that has great potential for the prevention and treatment of age-related disorders by regulating and activating the expression of neural protective proteins such as BDNF. This review discusses and analyzes the available scientific literature on the effects of curcumin on BDNF production and function in both in vitro and in vivo models of disease.

Adult neurogenesis research in China

Neural stem cells are multipotent stem cells that generate functional newborn neurons through a process called neurogenesis. Neurogenesis in the adult brain is tightly regulated and plays a pivotal role in the maintenance of brain function. Disruption of adult neurogenesis impairs cognitive function and is correlated with numerous neurologic disorders. Deciphering the mechanisms underlying adult neurogenesis not only advances our understanding of how the brain functions, but also offers new insight into neurologic diseases and potentially contributes to the development of effective treatments. The field of adult neurogenesis is experiencing significant growth in China. Chinese researchers have demonstrated a multitude of factors governing adult neurogenesis and revealed the underlying mechanisms of and correlations between adult neurogenesis and neurologic disorders. Here, we provide an overview of recent advancements in the field of adult neurogenesis due to Chinese scientists.

Antidepressive mechanisms of rhynchophylline in mice with chronic unpredictable stress-induced depression

ETHNOPHARMACOLOGICAL RELEVANCE

Uncaria rhynchophylla ([Mi] Jack) (gouteng) exerts antidepressive effects. Rhynchophylline (RH), a major component of U. rhynchophylla, exerts similar pharmacological effects to those of gouteng. Thus, RH may have antidepressive effects.

AIM OF THE STUDY

To investigate the anti-depressive effects of RH in chronic unpredictable mild stress (CUMS)-induced depressive mice. The anti-depressive mechanism of RH determined by measuring the 5-HT levels, the expressions of cAMP-response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in cortex and hippocampus.

MATERIALS AND METHODS

The behaviors of CUMS-induced depressive mice were measured using an open field test (OFT), forced swimming test (FST), and tail suspension test (TST). 5-HT levels were measured using an ELISA kits. The expressions of BDNF and CREB were determined using western blot test.

RESULTS

RH increased the frequency of rearing and grooming in the OFT and decreased the immobility time in the FST and TST. RH effectively increased the 5-HT level and BDNF and CREB expressions in the cortex and hippocampus.

CONCLUSION

Our findings indicate that the antidepressive mechanism of RH is related to increased levels of 5-HT from regulating CREB and BDNF expressions in cortex and hippocampus.

Efficacy of Curcumin on Cognitive Function Scores in Women with Premenstrual Syndrome and Dysmenorrhea: A Triple-Blind, Placebo-Controlled Clinical Trial

OBJECTIVE

To assess the efficacy of a curcumin supplementation on cognitive abilities in women suffering from premenstrual syndrome (PMS) and dysmenorrhea.

METHODS

A randomized, triple-blind, placebo-controlled trial was conducted from December 2019 to March 2020. A total of 124 women who had both PMS and dysmenorrhea were enrolled, and were equally and randomly assigned to the curcumin group or placebo group, 62 cases in each. Each subject received either a capsule containing 500 mg of curcuminoid, or a placebo daily, for 10 days (7 days before and until 3 days after the onset of menstrual bleeding) over 3 menstrual cycles. The cognitive abilities questionnaire was used to measures cognitive functions in 7 specific areas. Adverse reactions were monitored during and after the trial in both groups.

RESULTS

Administration of curcumin was associated with a significant increase in memory score (P=0.002), inhibitory control and selective attention (P=0.020), and total cognitive ability task (P=0.024). In addition, significant increments were found in scores of memory (3.5±3.1 vs. 0.4±3.8 in the curcumin and placebo groups, respectively; P=0.035), inhibitory control and selective attention (3.0±3.7 vs. 0.4±3.7; P=0.027) and total cognitive abilities (8.3±12.3 vs. 2.2±12.4; P=0.025) in the curcumin group versus placebo groups. Curcumin was safe and well-tolerable in current clinical trial.

CONCLUSION

Curcumin has a beneficial efficacy on cognitive function scores in women with PMS and dysmenorrhea, with improvements in memory, inhibitory control and selective attention. (Registration No. IRCT20191112045424N1, available at: https://www.irct.ir ).

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.

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

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

Schizophrenia, Curcumin and Minimizing Side Effects of Antipsychotic Drugs: Possible Mechanisms

Schizophrenia is a mental disorder characterized by episodes of psychosis; major symptoms include hallucinations, delusions, and disorganized thinking. More recent theories focus on particular disorders of interneurons, dysfunctions in the immune system, abnormalities in the formation of myelin, and augmented oxidative stress that lead to alterations in brain structure. Decreased dopaminergic activity and increased phospholipid metabolism in the prefrontal cortex might be involved in schizophrenia. Antipsychotic drugs used to treat schizophrenia have many side effects. Alternative therapy such as curcumin (CUR) can reduce the severity of symptoms without significant side effects. CUR has important therapeutic properties such as antioxidant, anti-mutagenic, anti-inflammatory, and antimicrobial functions and protection of the nervous system. Also, the ability of CUR to pass the blood-brain barrier raises new hopes for neuroprotection. CUR can improve and prevent further probable neurological and behavioral disorders in patients with schizophrenia. It decreases the side effects of neuroleptics and retains lipid homeostasis. CUR increases the level of brain-derived neurotrophic factor and improves hyperkinetic movement disorders. CUR may act as an added counteraction mechanism to retain cell integrity and defense against free radical injury. Thus it appears to have therapeutic potential for improvement of schizophrenia. In this study, we review several properties of CUR and its ability to improve schizophrenia and minimize the side effects of antipsychotic drugs, and we explore the underlying mechanisms by which CUR affects schizophrenia and its symptoms.

Ageing, Metabolic Dysfunction, and the Therapeutic Role of Antioxidants

The gradual ageing of the world population has been accompanied by a dramatic increase in the prevalence of obesity and metabolic diseases, especially type 2 diabetes. The adipose tissue dysfunction associated with ageing and obesity shares many common physiological features, including increased oxidative stress and inflammation. Understanding the mechanisms responsible for adipose tissue dysfunction in obesity may help elucidate the processes that contribute to the metabolic disturbances that occur with ageing. This, in turn, may help identify therapeutic targets for the treatment of obesity and age-related metabolic disorders. Because oxidative stress plays a critical role in these pathological processes, antioxidant dietary interventions could be of therapeutic value for the prevention and/or treatment of age-related diseases and obesity and their complications. In this chapter, we review the molecular and cellular mechanisms by which obesity predisposes individuals to accelerated ageing. Additionally, we critically review the potential of antioxidant dietary interventions to counteract obesity and ageing.

Case report: Alexander's disease with "head drop" as the main symptom and literature review

Alexander's disease (AxD) is a rare autosomal dominant hereditary disorder that is caused by the mutations in the GFAP gene, which encodes the glial fibrillary acidic protein (GFAP). This neurogenerative disease has many clinical manifestations, and the onset of disease spans a wide range of ages, from newborns to children, adults, and even the elderly. An overaccumulation of the expression of GFAP has a close causal relationship with the pathogenesis of Alexander's disease. Usually, the disease has severe morbidity and high mortality, and can be divided into three distinct subgroups that are based on the age of clinical presentation: infantile (0-2 years), juvenile (2-13 years), and adult (>13 years). Children often present with epilepsy, macrocephaly, and psychomotor retardation, while adolescents and adults mainly present with muscle weakness, spasticity, and bulbar symptoms. Atonic seizures are a type of epilepsy that often appears in the Lennox-Gastaut syndrome and myoclonic-astatic epilepsy in early childhood; however, the prognosis is often poor. Atonic episodes are characterized by a sudden or frequent reduction in muscle tone that can be local (such as head, neck, or limb) or generalized. Here, we report a 4-year-old girl whose main symptoms were intermittent head drop movements, which could break the frontal frame and even bleed in severe conditions. A video-encephalography (VEEG) showed that the nodding movements were atonic seizures. A head magnetic resonance imaging (MRI) revealed abnormal signals in the bilateral paraventricular and bilateral subfrontal cortex. The gene detection analyses indicated that the GFAP gene exon 1 c.262 C>T was caused by a heterozygous mutation, as both her parents were of the wild-type. The girl had no other abnormal manifestations except atonic seizures. She could communicate normally and go to kindergarten. After an oral administration of sodium valproate, there were no atonic attacks. Although epilepsy is a common symptom of Alexander's disease, atonic seizures have not been reported to date. Therefore, we report a case of Alexander's disease with atonic seizures as the main symptom and provide a review of the literature.

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

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

Protection against Morphine-Induced Inhibitory Avoidance Memory Impairment in Rat by Curcumin: Possible Role of Nitric Oxide/ cAMP-Response Element Binding Protein Pathway

BACKGROUND

Although a substantial body of research suggests curcumin (CUR) has the preventive potential in memory impairment, the mechanism by which CUR prevents memory loss is still being investigated. This study employs an inhibitory avoidance (IA) model to investigate whether CUR can prevent morphine (Mor)-induced memory impairment as well as the possible role of cAMP-response element binding (CREB) protein, and nitric oxide (NO) signaling in this mechanism.

METHODS

This experimental study was conducted at the Animal Lab of the Physiology Research Center, Kashan University of Medical Sciences (Kashan, Iran) in 2018. Forty rats were randomly divided into four groups: control, CUR (pretreatment gavage of CUR [10 mg/Kg] for 35 days), Mor (7.5 mg/Kg, i.p.), and CUR+Mor (n=10 per group). Following the evaluation of the IA memory and locomotor activity of the animals, the CREB protein expression in the hippocampus and NO metabolites (NOx) level in the brain tissue were also investigated. The data were analyzed using Sigmaplot software (version 14.0) by using the ANOVA, Kruskal-Wallis, Holm-Sidak, and Dunn's post hoc tests. P<0.05 was considered to be statistically significant.

RESULTS

In the Mor group, the IA memory of the rats was significantly impaired (P=0.001). CUR prevented the Mor-induced IA memory impairment (P=0.075). While the Mor treatment decreased the phosphorylated CREB (p-CREB) expression, the CUR+Mor cotreatment increased p-CREB expression (P=0.010). Nevertheless, the Mor treatment increased the total CREB expression (P=0.010). The NOx concentration in the brain tissue was decreased following the Mor treatment (P=0.500) but increased after the CUR+Mor cotreatment (P=0.001).

CONCLUSION

The present findings suggest that CUR prevents the memory impairment of rats, possibly through NO and its downstream CREB signaling.

Molecular and functional characterization of an evolutionarily conserved CREB-binding protein in the Lymnaea CNS

In eukaryotes, CREB-binding protein (CBP), a coactivator of CREB, functions both as a platform for recruiting other components of the transcriptional machinery and as a histone acetyltransferase (HAT) that alters chromatin structure. We previously showed that the transcriptional activity of cAMP-responsive element binding protein (CREB) plays a crucial role in neuronal plasticity in the pond snail Lymnaea stagnalis. However, there is no information on the molecular structure and HAT activity of CBP in the Lymnaea central nervous system (CNS), hindering an investigation of its postulated role in long-term memory (LTM). Here, we characterize the Lymnaea CBP (LymCBP) gene and identify a conserved domain of LymCBP as a functional HAT. Like CBPs of other species, LymCBP possesses functional domains, such as the KIX domain, which is essential for interaction with CREB and was shown to regulate LTM. In-situ hybridization showed that the staining patterns of LymCBP mRNA in CNS are very similar to those of Lymnaea CREB1. A particularly strong LymCBP mRNA signal was observed in the cerebral giant cell (CGC), an identified extrinsic modulatory interneuron of the feeding circuit, the key to both appetitive and aversive LTM for taste. Biochemical experiments using the recombinant protein of the LymCBP HAT domain showed that its enzymatic activity was blocked by classical HAT inhibitors. Preincubation of the CNS with such inhibitors blocked cAMP-induced synaptic facilitation between the CGC and an identified follower motoneuron of the feeding system. Taken together, our findings suggest a role for the HAT activity of LymCBP in synaptic plasticity in the feeding circuitry.

A behavioral and molecular study; ameliorated anxiety-like behavior and cognitive dysfunction in a rat model of chronic unpredictable stress treated with oregano extract

OBJECTIVE

Chronic stress is considered a severe risk factor leading to various disorders, including anxiety and cognitive decline. The present study aimed to investigate the effects of Origanum vulgare (oregano) extract on improving anxiety-like behavior and learning and memory defection caused by chronic unpredictable stress (CUS).

METHOD

A 10-day CUS protocol was executed on male rats, and on day 10, their anxiety, learning, and memory status were evaluated. After that, in addition to the CUS, the rats were treated with the oregano extract for 2 weeks. Then, the expression of BDNF, TrkB, and TLR2/4 genes in the hippocampus and prefrontal cortex of the rats was evaluated. Also, the liver- and kidney-related serum parameters, including triglycerides, total cholesterol, HDL, LDL, creatinine, urea, serum glucose, alanine aminotransferase, and aspartate aminotransferase were assessed. Further, the extract's lethal effect and its impact on animals' body weight were investigated.

RESULTS

Behavioral tests confirmed the anxiety-like behavior and learning-memory function impairment caused by CUS. In contrast, the administration of the extract could significantly alleviate the mental deficiencies and diminished anxiety-like behaviors. Molecular assessments showed that CUS could markedly decrease the BDNF and TrkB genes' expression levels while increasing that of TLR2 and TLR4. In contrast, in extract-treated animals, mRNA levels of BDNF and TrkB considerably increased, yet TLR2 and TLR4 mRNA levels reduced. Additionally, consumption of the extract caused weight gain, while having no lethality and detrimental effect on the liver and kidneys functions.

CONCLUSIONS

These findings indicate the anxiolytic properties of the extract and its improving effect on cognitive dysfunction.

Curcumin can improve Parkinson's disease via activating BDNF/PI3k/Akt signaling pathways

Parkinson's disease is a common progressive neurodegenerative disease, and presently has no curative agent. Curcumin, as one of the natural polyphenols, has great potential in neurodegenerative diseases and other different pathological settings. The brain-derived neurotrophic factor (BDNF) and phosphatidylinositol 3 kinase (PI3k)/protein kinase B (Akt) signaling pathways are significantly involved nerve regeneration and anti-apoptotic activities. Currently, relevant studies have confirmed that curcumin has an optimistic impact on neuroprotection via regulating BDNF and PI3k/Akt signaling pathways in neurodegenerative disease. Here, we summarized the relationship between BDNF and PI3k/Akt signaling pathway, the main biological functions and neuroprotective effects of curcumin via activating BDNF and PI3k/Akt signaling pathways in Parkinson's disease. This paper illustrates that curcumin, as a neuroprotective agent, can delay the progression of Parkinson's disease by protecting nerve cells.

Therapeutic role of curcumin in adult neurogenesis for management of psychiatric and neurological disorders: a scientometric study to an in-depth review

Aberrant neurogenesis is a major factor in psychiatric and neurological disorders that have significantly attracted the attention of neuroscientists. Curcumin is a primary constituent of curcuminoid that exerts several positive pharmacological effects on aberrant neurogenesis. First, it is important to understand the different processes of neurogenesis, and whether their dysfunction promotes etiology as well as the development of many psychiatric and neurological disorders; then investigate mechanisms by which curcumin affects neurogenesis as an active participant in pathophysiological events. Based on scientometric studies and additional extensive research, we explore the mechanisms by which curcumin regulates adult neurogenesis and in turn affects psychiatric diseases, i.e., depression and neurological disorders among them traumatic brain injury (TBI), stroke, Alzheimer's disease (AD), Gulf War Illness (GWI) and Fragile X syndrome (FXS). This review aims to elucidate the therapeutic effects and mechanisms of curcumin on adult neurogenesis in various psychiatric and neurological disorders. Specifically, we discuss the regulatory role of curcumin in different activities of neural stem cells (NSCs), including proliferation, differentiation, and migration of NSCs. This is geared toward providing novel application prospects of curcumin in treating psychiatric and neurological disorders by regulating adult neurogenesis.

An Update on the Exploratory Use of Curcumin in Neuropsychiatric Disorders

Curcumin is a polyphenol extracted from the rhizome of the turmeric plant. Beyond its common use as a culinary spice in Eastern Asia, curcumin has been proposed as a therapeutic compound due to its antioxidant, anti-inflammatory and neuroprotective properties. Thus, its efficacy has been evaluated in various inflammatory-based psychiatric disorders, such as schizophrenia, depression, or autism. Our aim is to review those preclinical and clinical studies carried out in psychiatric disorders whose therapeutic approach has involved the use of curcumin and, therefore, to discern the possible positive effect of curcumin in these disorders. Preclinical studies and completed clinical trials of curcumin for psychiatric disorders published from January 2005 to October 2021 were identified through searching relevant databases until 31st October 2021. Sixty-five preclinical studies and 15 clinical trials and open-label studies were selected. Results showed a bias toward studies in depression and, to a lesser extent, schizophrenia. In all disorders, the results were positive in reducing psychiatric deficits. Despite the considerable number of beneficial outcomes reported, the small number of trials and the heterogeneity of protocols make it difficult to draw solid conclusions about the real potency of curcumin in psychiatric disorders.

Phytochemicals as inhibitors of tumor necrosis factor alpha and neuroinflammatory responses in neurodegenerative diseases

Inflammatory processes and proinflammatory cytokines have a key role in the cellular processes of neurodegenerative diseases and are linked to the pathogenesis of functional and mental health disorders. Tumor necrosis factor alpha has been reported to play a major role in the central nervous system in Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis and many other neurodegenerative diseases. Therefore, a potent proinflammatory/proapoptotic tumor necrosis factor alpha could be a strong candidate for targeted therapy. Plant derivatives have now become promising candidates as therapeutic agents because of their antioxidant and chemical characteristics, and anti-inflammatory features. Recently, phytochemicals including flavonoids, terpenoids, alkaloids, and lignans have generated interest as tumor necrosis factor alpha inhibitor candidates for a number of diseases involving inflammation within the nervous system. In this review, we discuss how phytochemicals as tumor necrosis factor alpha inhibitors are a therapeutic strategy targeting neurodegeneration.

Mitragynine improves cognitive performance in morphine-withdrawn rats

RATIONALE

The treatment of opiate addiction is an unmet medical need. Repeated exposure to opiates disrupts cognitive performance. Opioid substitution therapy, with, e.g., methadone, may further exacerbate the cognitive deficits. Growing evidence suggests that mitragynine, the primary alkaloid from the Kratom (Mitragyna speciosa) leaves, may serve as a promising alternative therapy for opiate addiction. However, the knowledge of its health consequences is still limited.

OBJECTIVES

We aimed to examine the cognitive effects of mitragynine substitution in morphine-withdrawn rats. Furthermore, we asked whether neuronal addiction markers like the brain-derived neurotrophic factor (BDNF) and Ca²⁺/calmodulin-dependent kinase II alpha (αCaMKII) might mediate the observed effects.

METHODS

Male Sprague-Dawley rats were given morphine at escalating doses before treatment was discontinued to induce a spontaneous morphine withdrawal. Then, vehicle or mitragynine (5 mg/kg, 15 mg/kg, or 30 mg/kg) substitution was given for 3 days. A vehicle-treated group was used as a control. Withdrawal signs were scored after 24 h, 48 h, and 72 h, while novel object recognition (NOR) and attentional set-shifting (ASST) were tested during the substitution period.

RESULTS

Discontinuation of morphine significantly induced morphine withdrawal signs and cognitive deficit in the ASST. The substitution with mitragynine was able to alleviate the withdrawal signs. Mitragynine did not affect the recognition memory in the NOR but significantly improved the reversal learning deficit in the morphine-withdrawn rats.

CONCLUSIONS

These data support the idea that mitragynine could be used as safe medication therapy to treat opiate addiction with beneficial effects on cognitive deficits.

Potential Role of Curcumin for the Treatment of Major Depressive Disorder

Curcumin is the major biologically active polyphenolic constituent in the turmeric plant (Curcuma longa) that has been shown to have antioxidant, anti-inflammatory, neuroprotective, anticancer, antimicrobial, and cardioprotective effects. Interest in curcumin as a treatment for mental health conditions has increased and there is an expanding body of preclinical and clinical research examining its antidepressant and anxiolytic effects. In this narrative review, human trials investigating the effects of curcumin for the treatment of depression or depressive symptoms are summarised. Using findings from in vitro, animal, and human trials, possible biological mechanisms associated with the antidepressant effects of curcumin are also explored. To increase the understanding of curcumin for the treatment of depression, directions for future research are proposed.

Herbal Plethora for Management of Neurodegenerative Disorders: An Invigorating Outlook

Objective:

Oxidative stress, proteasomal impairment, mitochondrial dysfunction, and accumulation of abnormal protein aggregates have shovelled a major section of the senior population towards neurodegenerative disorders. Although age, genetic and environmental factors are thought to play a significant role, drug abuse is considered to be a potent trigger in Parkinsonism among the young generation. The present study is a critical examination of herbal resources for attenuation of neurodegeneration.

Materials and Methods:

The following electronic databases have been used to search for literature: MEDLINE, Scopus, PubMed, and EMBASE

Results :

Paying heed to the prevalence of neurodegenerative disorders such as Alzheimer’s and Parkinson’s, the current review encompasses the pathogenesis of neurodegeneration at the cellular level and possible prospects to overcome the challenge sailing through the ocean of herbal boon. The United States’s Alzheimer’s Association states that deaths attributable to heart disease in the country fell by 11% between 2000 and 2015, while deaths from neurodegenerative diseases increased by a staggering 123% making it, the world’s sixth-leading cause of death. The irreversible pathological damage amounts to cognitive loss, dementia, Amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD) Alzheimer’s disease (AD). Various herbal drugs like Brahmi, Shankhpushpi, and Amla are reported to be rich in phytoconstituents like flavonoids, glycosides, alkaloids, fatty acids, sterols, tannins, saponins, and terpenes that have remarkable antioxidant potential and could be explored for the same to prevent neuronal necrosis.

Conclusion:

It is also believed that herbal medicines are more effective and less toxic than synthetic drugs.

Beneficial Effect of Phenytoin and Carbamazepine on GFAP Gene Expression and Mutant GFAP Folding in a Cellular Model of Alexander's Disease

Alexander’s disease (AxD) is a rare, usually relentlessly progressive disorder of astroglial cells in the central nervous system related to mutations in the gene encoding the type III intermediate filament protein, glial fibrillary acidic protein (GFAP). The pathophysiology of AxD is only partially understood. Available data indicate that an excessive GFAP gene expression may play a role. In particular, a “threshold hypothesis” has been reported, suggesting that mutant GFAP representing about 20% of the total cellular GFAP should be sufficient to cause disease. Thus, strategies based on reducing cellular mutant GFAP protein levels and/or activating biological processes involved in the correct protein folding could be effective in counteracting the toxic effect of misfolded GFAP. Considering that clomipramine (CLM), which has been selected by a wide small molecules screening as the greatest inhibitory potential drug against GFAP expression, is contraindicated because of its proconvulsant activity in the infantile form of AxD, which is also characterized by the occurrence of epileptic seizures, two powerful antiepileptic agents, carbamazepine (CBZ) and phenytoin (PHT), which share specific stereochemical features in common with CLM, were taken into consideration in a reliable in vitro model of AxD. In the present work, we document for the first time that CBZ and PHT have a definite inhibitory effect on pathological GFAP cellular expression and folding. Moreover, we confirm previous results of a similar beneficial effect of CLM. In addition, we have demonstrated that CBZ and CLM play a refolding effect on mutant GFAP proteins, likely ascribed at the induction of CRYAB expression, resulting in the decrease of mutant GFAP aggregates formation. As CBZ and PHT are currently approved for use in humans, their documented effects on pathological GFAP cellular expression and folding may indicate a potential therapeutic role as disease-modifying agents of these drugs in the clinical management of AxD, particularly in AxD patients with focal epilepsy with and without secondary generalization.

Chinese Pharmacopoeia Revisited: A Review of Anti-Depression Herbal Sources

Depression, which can be accompanied by many fatal diseases and a low life quality, has become the leading cause of ill health and disability worldwide. However, Chinese Pharmacopoeia, the most authoritative and evidence-based encyclopedia of Traditional Chinese Medicine (TCM), could contain leads and insights into the development of new antidepressant drugs. In this work, nine herbal medicines with ‘dispel melancholy functions’ specifically documented in Chinese Pharmacopoeia have been comprehensively reviewed with respect to clinical trials, and phytochemical and pharmacological aspects. The nine drugs are Rosae Chinensis Flos, Croci Stigma, Albiziae Cortex and Flos, Roase Rugosae Flos, Curcumae Radix, Hyperici Perforati Herba, Cyperi Rhizoma and Bupleuri Radix. The mechanisms of action of their functional antidepressant compounds, including gallic acid, hypericin, kaempferol, crocetin, crocin, quercetin, luteolin, isorhamnetin, curcumin, hyperforin, adhyperforin, catechin, rutin, puerarin, and saikosaponins A and D, have been collected and discussed. These traditional Chinese herbs and their active compounds provide a promising resource to develop effective new antidepressant drugs in future. Moreover, mechanistic investigations, safety verification and large-scale clinical trials are still expected to finally transform such TCM-based antidepressant resources to new drugs for patients suffering from depression.

An overview of the behavioral, neurobiological and morphological effects of topiramate in rats exposed to chronic unpredictable mild stress

The environmental psychological stress causes depressive disorders. Stress causes many neurobiological, neurodegenerative changes in brain. Topiramate (TPM) is used in the treatment of epilepsy and psychiatric diseases. However, there are conflicting findings that TPM disrupts cognitive functions. We aimed to investigate the effects of TPM on depression, anxiety, learning and memory as well as neurobiological, morphological changes in rats exposed to chronic unpredictable mild stress (CUMS). After CUMS was formed by random application of nine mild stressors for 45 days, TPM (at doses of 0.1, 1, 10, 100 mg/kg) was administered for 21 days. Sucrose preference, locomotor activity, forced swimming, elevated plus maze and Morris water maze tests were performed. Corticosterone, BDNF (Brain-derived neurotrophic factor) and glutamate levels and volumes of hippocampus were evaluated. Body weights of the rats were measured. Immobilization time increased in CUMS, CUMS + TPM0.1 in forced swimming test and time spent in platform quadrant increased in Control + TPM1, CUMS, CUMS + TPM0.1, CUMS + TPM1 in Morris water maze test. Control + TPM1 decreased distance to platform in Morris water maze while CUMS + TPM100 increased. Learning is impaired in CUMS + TPM100 while it is improved in Control + TPM1. BDNF levels increased in CUMS and glutamate levels increased in CUMS, CUMS + TPM10. Body weight decreased in CUMS, CUMS + TPM0.1, CUMS + TPM1, CUMS + TPM100. Hippocampus volumes increased in CUMS. In conclusion, CUMS improved cognition and this finding was supported by the increase of BDNF levels and volume of hippocampus. TPM 1 mg/kg improved cognition in non-stressed rats. TPM 0.1 and 1 mg/kg improved while TPM 100 mg/kg impaired memory in rats exposed to stress.

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

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

Dietary biomolecules as promising regenerative agents for peripheral nerve injury: An emerging nutraceutical-based therapeutic approach

Peripheral nerve damage is a debilitating condition that can result in partial or complete functional loss as a result of axonal degeneration, as well as lifelong dependence. Many therapies have been imbued with a plethora of positive features while posing little risks. It is worth noting that these biomolecules work by activating several intrinsic pathways that are known to be important in peripheral nerve regeneration. Although the underlying mechanism is used for accurate and speedy functional recovery, none of them are without side effects. As a result, it is believed that effective therapy is currently lacking. The dietary biomolecules-based intervention, among other ways, is appealing, safe, and effective. Upregulation of transcription factors, neurotrophic factors, and growth factors such as NGF, GDNF, BDNF, and CTNF may occur as a result of these substances' dietary intake. Upregulation of the signaling pathways ERK, JNK, p38, and PKA has also been seen, which aids in axonal regeneration. Although several mechanistic approaches to understanding their involvement have been suggested, more work is needed to reveal the amazing properties of these biomolecules. We have discussed in this article that how different dietary biomolecules can help with functional recovery and regeneration after an injury. PRACTICAL APPLICATIONS: Based on the information known to date, we may conclude that treatment techniques for peripheral nerve injury have downsides, such as complications, donor shortages, adverse effects, unaffordability, and a lack of precision in efficacy. These difficulties cast doubt on their efficacy and raise severe concerns about the prescription. In this situation, the need for safe and effective therapeutic techniques is unavoidable, and dietary biomolecules appear to be a safe, cost-efficient, and effective way to promote nerve regeneration following an injury. The information on these biomolecules has been summarized here. Upregulation of transcription factors, neurotrophic factors, and growth factors, such as NGF, GDNF, BDNF, and CTNF, as well as the ERK, JNK, p38, and PKA, signaling pathways, may stimulate axonal regeneration.

Chronic light deprivation induces different effects on spatial and fear memory and hippocampal BDNF/TRKB expression during light and dark phases of rat diurnal rhythm

Disruptions in light/dark cycle have been associated with an altered ability to form and retrieve memory in human and animals. Animal studies have shown that chronic light deprivation disrupts the light/dark cycle and alters the neural connections that mediate hippocampal memory formation. In order to better understand how light deprivation affects the formation and retrieval of memory in adult rats, we examined the effect of total darkness on spatial and auditory fear learning and memory formation and BDNF/TRKB protein levels during the light and dark phases of the rat circadian cycle. Male Wistar rats (n = 60), were randomly divided into two main groups: normal rearing (NR, 12 h light/dark cycle for 3 weeks) and dark rearing (DR, kept in constant darkness for 3 weeks); and each of these groups had a "light (day)" and "dark (night)" sub-group. After 3 weeks, the Morris Water maze and auditory fear conditioning were used to assess spatial and fear memory acquisition and retrieval, respectively. BDNF and TRKB protein levels in the hippocampus of rats from the four sub-groups were measured by Western blot, at the completion of the 3 week constant darkness exposure and after the behavioral experiments. These studies revealed that DR for 3 weeks impaired spatial memory retrieval and enhanced extinction of auditory fear memory specifically during the light (day) phase. DR also eliminated the normal fluctuations in BDNF/TRKB levels observed in the hippocampus across the light/dark cycle.

Neuroprotective Role of Polyphenols in Treatment of Neurological Disorders: A Review

: The most frequent illnesses characterized by the gradual malfunctioning of brain neurons are neurodegenerative disorders (NDs). Genetic mutations and a range of biological processes can produce NDs. Alzheimer's disease (AD), Parkinson's disease (PD), and Multiple Sclerosis (MS) are all related to oxidative stress (OS). Reduced brain activity has become a greater health threat with a growing elderly population. It causes some pathophysiological alterations and is an important risk factor for a range of neurodegenerative illnesses. An increase in reactive oxygen species (ROS) can cause neuronal cell death, and it is thus essential to control ROS levels to maintain normal neuronal activity. Synthetic medicines are often used to treat neurological disorders; however, harmful effects have been reported. Multiple bodies of research have shown the effectiveness of polyphenols in the treatment of various NDs due to their negligible side effects. This review article describes the neuroprotection effects of polyphenols such as resveratrol, epigallocatechin-3-gallate, curcumin, and quercetin, as well as the signaling pathways and immune response controls through polyphenols.

Therapeutic Potential of Curcumin in Reversing the Depression and Associated Pseudodementia via Modulating Stress Hormone, Hippocampal Neurotransmitters, and BDNF Levels in Rats

Depressive state adversely affects the memory functions, especially in the geriatric population. The initial stage of memory deficits associated with depression is particularly called as pseudodementia. It is the starting point of memory disturbance before dementia. The purpose of this research was to study depression and its consequent pseudodementia. For this purpose 24 male albino Wistar rats were divided into four groups. Depression was induced by 14 days of chronic restraint stress (CRS) daily for 4 h. After developing a depression model, pattern separation test was conducted to monitor pseudodementia in rats. Morris water maze test (MWM) was also performed to observe spatial memory. It was observed that model animals displayed impaired pattern separation and spatial memory. Treatment was started after the development of pseudodementia in rats. Curcumin at a dose of 200 mg/kg was given to model rats for one week along with the stress procedure. Following the treatment with curcumin, rats were again subjected to the aforementioned behavioral tests before decapitation. Corticosterone levels, brain derived neurotrophic factor (BDNF) and neurochemical analysis were conducted. Model rats showed depressogenic behavior and impaired memory performance. In addition to this, high corticosterone levels and decreased hippocampal BDNF, 5-HT, dopamine (DA), and acetylcholine (ACh) levels were also observed in depressed animals. These behavioral biochemical and neurochemical changes were effectively restored following treatment with curcumin. Hence, it is suggested from this study that pseudodementia can be reversed unlike true dementia by controlling the factors such as depression which induce memory impairment.

Baicalin ameliorates chronic unpredictable mild stress-induced depression through the BDNF/ERK/CREB signaling pathway

Brain-derived neurotrophic factor (BDNF) can activate the extracellular regulated protein kinase (ERK)/cAMP response element binding protein (CREB) cascade revealing an important role in antidepressant effects. Here, we studied the neuroprotective effect of baicalin (BA) in mice with chronic unpredictable mild stress (CUMS)-induced via a BDNF/ERK/CREB signaling pathway. Depression was induced via six weeks of CUMS in male ICR mice, and drug therapy was given simultaneously for the last three weeks. Cognitive dysfunctions were then evaluated via sucrose preference test (SPT), open field test (OFT), Morris water maze test (MWM), tail suspension test (TST), and novelty suppressed feeding test (NSF). Western blot and real-time PCR were then used to detect the relative expression of ERK, CREB, p-ERK, and p-CREB. Integrated optical density (IOD) tests of p-ERK and p-CREB were then evaluated via immunofluorescence. The behavior results showed that the cognitive dysfunctions increased in the CUMS group versus the control (CON) group (p < 0.01). There were decreases in fluoxetine (FLU) and BA groups (p < 0.05, p < 0.01). The protein ratios of p-ERK/ERK, p-CREB/CREB and ERK mRNA, and CREB mRNA expression decreased in the CUMS group (p < 0.01) and markedly increased in the FLU and BA groups (p < 0.05, p < 0.01). The IOD value of the p-ERK and p-CREB in the CUMS group was decreased versus the CON group (p < 0.01), and these changes were improved via BA and FLU treatment (p < 0.05, p < 0.01). This study indicated that BA can improve cognitive functions and has antidepressant effects in mice, which may be associated with activation of the BDNF/ERK/CREB signaling pathway in the hippocampus.

The efficacy and acceptability of curcumin for the treatment of depression or depressive symptoms: A systematic review and meta-analysis

INTRODUCTION

Curcumin, a potential natural substance is a promising complementary and alternative therapeutic intervention for depression or depressive symptoms. We undertook a systematic review and meta-analysis to evaluate the efficacy and acceptability.

METHODS

PubMed, EMBASE, PsycInfo, Web of Science, Cochrane Library and ClinicalTrials.gov were searched from the inception up until March 4, 2020. The Outcomes were depressive symptoms, response rates, drop-out rates, and adverse effects.

RESULTS

A total of 594 patients from ten trials were subjected to meta-analysis. Three trials were judged to be at high risk of bias, four at unclear risk of bias and three at low risk of bias. Most of the domains for risk of bias were at low risk or unclear risks and three domains at high risks. The pooling results suggested a significant difference in depression or depressive symptoms(SMD= -0.32, 95% CI: -0.50 to -0.13, I²=15%, n=594) and response rates (OR=3.20, 95% CI: 1.28-7.99, I²=35%, n=271). However, there was no difference between drop-out rates (OR=1.06, 95% CI: 0.58-1.93, I²=0%, n=594), digestive symptoms (OR=1.27, 95% CI: 0.69-2.32, I²=0%, n=284) and neurological symptoms (OR=1.08, 95% CI: 0.49-2.36, I²=0%, n=284). Subgroup analysis showed depression was associated with a reduction(SMD= -0.35, 95% CI: -0.56 to -0.15, I²=7%, n=432) but depressive symptoms were not (SMD= -0.17, 95% CI: -0.61 to 0.26, I²=40%, n=162).

CONCLUSIONS

The evidence quality is low, indicating that there is great uncertainty about the efficacy and acceptability of curcumin for the treatment of depression or depressive symptoms.

Core prescription pattern of Chinese herbal medicine for depressive disorders in Taiwan: a nationwide population-based study

Background

Depressive disorders (DD) affect not only mood and behavior but also various physical functions. Traditional Chinese medicine (TCM) has been shown to have some benefits in treating DD. However, one formula or one single herb might be not show high efficacy when used to treat depression. Thus, this study aimed to examine the core prescription pattern of Chinese herbal medicine (CHM) among patients with DD in Taiwan as a reference for related research and clinical applications.

Methods

All patients, who had been diagnosed with major depressive disorder or minor depression or dysthymia without any other baseline diseases and had at least one CHM outpatient clinical visit from 2002 to 2011, were extracted from three randomly sampled cohorts, namely the 2000, 2005 and 2010 cohorts of the National Health Insurance Research Database (NHIRD) of Taiwan. The collected data was analyzed to explore the patterns of herbal products.

Results

There were 197,146 patients with a diagnosis of DD and of these 1806 subjects had only a diagnosis of DD and utilized CHM. The most common formula was Gan-Mai-Da-Zao-Tang (12.19%), while Suan-Zao-Ren (3.99%) was the most commonly prescribed single herb. The core pattern of prescriptions consisted of a combination of Gan-Mai-Da-Zao-Tang, Jia-Wei-Xiao-Yao-San, Chai-Hu-Jia-Long-Gu-Mu-Li-Tang, He-Huan-Pi, Yuan-Zhi and Shi-Chang-Pu.

Conclusions

This study describes the CHM core prescription pattern used to treat patients in Taiwan with DD and it is a potential candidate for study in future pharmacological or clinical trials targeting DD.

Curcumin mitigates neurotoxic and neurobehavioral changes of gentamicin and sodium salicylate in rats by adjusting oxidative stress and apoptosis

Currently, antibiotics and salicylates are the most highly consumed medications worldwide. The side effects of these pharmaceuticals on the nervous system have been little investigated. Thus, this study aimed to examine the influence of the gentamicin (GM) and sodium salicylates (SS) on neurobehavioral functions, including locomotors function, memory, and sensorimotor functions together with gamma-aminobutyric acid (GABA) neurotransmitter levels. Also, oxidative stress, lipid peroxidation, and apoptotic indicators of brain tissue were assessed. Additionally, the histopathological architecture of brain tissues was investigated. This study also evaluated the curcumin (CUR) efficacy to counteract the GM or SS induced neurotoxic impacts in rats. For this purpose, seven groups were administered physiological saline (1 ml/rat; orally), olive oil (1 ml/rat; orally), CUR (50 mg/kg bwt; orally), GM (120 mg/kg bwt; intraperitoneally), SS (300 mg /kg bwt; intraperitoneally), CUR + GM, or CUR + SS for consecutive 15 days. The results revealed that GM and SS exposure evoked impaired memory, sensorimotor deficit functions, and depressive-like behavior together with the depletion of GABA. GM and SS exposure elevated malondialdehyde and Caspase-3 levels, but total antioxidant capacity and Bcl-2 levels were reduced. Besides, GM and SS exposure induced distinct pathological perturbations in cerebral cortices and hippocampus tissues. CUR significantly reversed the GM and SS harmful impacts. In conclusion, these findings verified that CUR could be a biologically efficient protective intervention against GM and SS induced neurotoxic impacts and neurobehavioral aberrations.

AMPA receptors mediate the pro-cognitive effects of electrical and optogenetic stimulation of the medial prefrontal cortex in antidepressant non-responsive Wistar-Kyoto rats

BACKGROUND

The chronic mild stress (CMS) procedure is a widely used animal model of depression, and its application in Wistar-Kyoto (WKY) rats has been validated as a model of antidepressant-refractory depression. While not responding to chronic treatment with antidepressant drugs, WKY rats do respond to acute deep brain stimulation (DBS) of the medial prefrontal cortex (mPFC). In antidepressant-responsive strains there is evidence suggesting a role for AMPA subtype of glutamate receptor in the action mechanism of both antidepressants and DBS.

METHODS

Animals were subjected to CMS for 6 to 8 weeks; sucrose intake was monitored weekly and novel object recognition (NOR) test was conducted following recovery from CMS. Wistars were treated chronically with venlafaxine (VEN), while WKY were treated acutely with either DBS, optogenetic stimulation (OGS) of virally-transduced (AAV5-hSyn-ChR2-EYFP) mPFC or ventral hippocampus, or acute intra-mPFC injection of the AMPA receptor positive allosteric modulator CX-516. The AMPA receptor antagonist NBQX was administered, at identical sites in mPFC, immediately following the exposure trial in the NOR.

RESULTS

Sucrose intake and NOR were suppressed by CMS, and restored by VEN in Wistars and by DBS, OGS, or CX-516 in WKY. However, OGS of the ventral hippocampal afferents to mPFC was ineffective. A low dose of NBQX selectively blocked the procognitive effect of VEN, DBS and OGS.

CONCLUSIONS

These results suggest that activation of AMPA receptors in the mPFC represents a common pathway for the antidepressant effects of both conventional (VEN) and novel (DBS, OGS) antidepressant modalities, in both antidepressant responsive (Wistar) and antidepressant-resistant (WKY) rats.

Evaluation of the Effect of Hypericum triquetrifolium Turra on Memory Impairment Induced by Chronic Psychosocial Stress in Rats: Role of BDNF

BACKGROUND

Chronic psychosocial stress impairs memory function and leads to a depression-like phenotype induced by a persistent status of oxidative stress. Hypericum perforatum L. (St. John's wort) is widely used to relieve symptoms of anxiety and depression; however, its long-term use is associated with adverse effects. Hypericum triquetrifolium Turra is closely related to H. perforatum. Both plants belong to Hypericaceae family and share many biologically active compounds. Previous work by our group showed that methanolic extracts of H. triquetrifolium have potent antioxidant activity as well as high hypericin content, a component that proved to have stress-relieving and antidepressant effects by other studies. Therefore, we hypothesized that H. triquetrifolium would reduce stress-induced cognitive impairment in a rat model of chronic stress.

OBJECTIVE

To determine whether chronic treatment with H. triquetrifolium protects against stress-associated memory deficits and to investigate a possible mechanism.

METHODS

The radial arm water maze (RAWM) was used to test learning and memory in rats exposed to daily stress using the resident-intruder paradigm. Stressed and unstressed rats received chronic H. triquetrifolium or vehicle. We also measured levels of brain-derived neurotrophic factor (BDNF) in the hippocampus, cortex and cerebellum.

RESULTS

Neither chronic stress nor chronic H. triquetrifolium administration affected performance during acquisition. However, memory tests in the RAWM showed that chronic stress impaired different post-encoding memory stages. H. triquetrifolium prevented this impairment. Furthermore, hippocampal BDNF levels were markedly lower in stressed animals than in unstressed animals, and chronic administration of H triquetrifolium chronic administration protected against this reduction. No significant difference was observed in the effects of chronic stress and/or H. triquetrifolium treatment on BDNF levels in the cerebellum and cortex.

CONCLUSION

H. triquetrifolium extract can oppose stress-associated hippocampus-dependent memory deficits in a mechanism that may involve BDNF in the hippocampus.

Vitamin C protects against chronic social isolation stress-induced weight gain and depressive-like behavior in adult male rats

Objective. Considering the importance of ghrelin in stress-induced hyperphagia and a role of antioxidants in decreasing body weight, in the present study, the effect of vitamin C (VitC) on ghrelin secretion and food intake following chronic social isolation (CIS) was evaluated in rats.Methods. Thirty two male Wistar rats (200-220g) were randomly divided into: control, VitC, CIS, and CIS + VitC groups. Animals received VitC (500 mg/kg/day)/saline by gavage for 3 weeks. For 24 h cumulative and post 18-20 h fasting food intake, fasting plasma ghrelin level, and body weight were measured. Gastric histopathology was also evaluated.Results. Results showed a marked increase in fasting plasma ghrelin and food intake in stressed rats compared to controls. VitC prevented the increases in stressed rats. Histological assessment indicated a positive effect of VitC on gastric glandular cells compared to control, an effect that might partially be a reason of significant increase of plasma ghrelin levels in VitC rats. Elevated plasma ghrelin in VitC group was even higher than that one in stressed group, whereas there were no significant changes in the food intake. Assessment of the percentage of changes in body weight during 21 days showed a significant increase in stressed rats compared to controls. Vitamin C treatment prevented this increase. Stressed rats also displayed depression-like behavior as indicated by sucrose test, whereas VitC ameliorated it.Conclusions. The data of the present study indicate that VitC may overcome ghrelin-induced hyperphagia and improve the abnormal feeding and depressive behavior in CIS rats.

Honey protects against chronic unpredictable mild stress induced- intestinal barrier disintegration and hepatic inflammation

Chronic stress is linked to liver injury by increasing intestinal permeability to lipopolysaccharide (LPS), which in turn can result in systemic and liver inflammation and damage. Beneficial effect of honey in the prevention of liver injury has been shown in previous studies, but mechanisms underlying are still less known. Here, we examined the therapeutic impacts of honey on intestinal nuclear factor-κB (NF-κB; an important regulator of stress-induced immune and inflammatory responses) and ileal tight junction (TJ) proteins of claudin-1 and ZO-1, serum LPS, liver inflammation and oxidative markers of malondialdehyde (MDA), nitric oxide (NO), (erythroid-derived 2)-like 2 (Nrf2), tumor necrosis factor (TNF)-α and total antioxidant capacity (TAC) following chronic unpredictable mild stress (CUMS) using Western blotting, ELISA kit and spectrophotometry. Male rats were subjected to CUMS for 28 consecutive days. Honey (0.2 and 2 g/kg/day, by gavage) was administered pretreatment (10 days) and during stress. Honey reduced stress-induced LPS elevation by preventing reduction in the intestinal TJ proteins of claudin-1 and ZO-1, while did not affect NF-kB levels. In liver, honey significantly suppressed stress-induced increase in MDA, NO, TNF-α and Nrf2 expression and normalized TAC. Noteworthy, honey high-dose provoked a greater decrease in TNF-α, Nrf2 and LPS levels than honey low-dose. Together, our study indicated that honey protects against stress-induced liver damage by modulating at least two pathways; intestinal barrier protection via increased TJ protein complex expression, and hepatic TAC protection that may be involved in the inhibition of MDA, NO, TNF-α and Nrf2 expression.

Xiaoyao Pills Attenuate Inflammation and Nerve Injury Induced by Lipopolysaccharide in Hippocampal Neurons In Vitro

Lipopolysaccharides (LPS) are proinflammation mediators that can induce the inflammatory model of the hippocampal neuron, and neuroinflammation participates in the pathophysiology of depression. Xiaoyao Pill is a classical Chinese medicine formula that has been used for the treatment of mental disorders such as depression in China since the Song dynasty. We established a hippocampal neuronal cell inflammation model by LPS and investigate the intervention effect and mechanism of Xiaoyao Pills. The expression levels of IL-6, TNF-α, IDO, 5-HT, brain-derived neurotrophic factor, and β-nerve growth factor were detected by enzyme-linked immunosorbent assay. mRNA levels of IL-6, TNF-α, 5-HT1A, IDO-1, brain-derived neurotrophic factor, nerve growth factor, tropomyosin receptor kinase B, tropomyosin receptor kinase A, and cAMP response element-binding protein were detected by reverse transcription-polymerase chain reaction. To further validate, protein expression was determined by western blot and immunofluorescence. Lipopolysaccharide-induced neuroinflammatory state resulted in the release of IL-6, TNF-α, and IDO and a decrease of BDNF, NGF, TrkB, TrkA, CREB, p-CREB, p-CREB/CREB, and SYP and inhibited hippocampal neurogenesis in the hippocampal neuron. Xiaoyao Pills significantly decreased the levels of IL-6, TNF-α, and IDO in cell supernatant and increased the expression of BDNF, NGF, TrkB, TrkA, CREB, p-CREB, p-CREB/CREB, and SYP as well as the average optical density of BrdU/NeuN double-labelled positive cells. Our study shows that lipopolysaccharides induce inflammation and nerve damage in hippocampal neurons, which are closely related to the pathological mechanism of depression. Xiaoyao Pills (XYW) play an important neuroprotective effect, which is related to its inhibition of neuronal inflammation and promoting the recovery of nerve injury. These results provide a pharmacologic basis for the treatment of depression of XYW in clinical application.

Boosting the autophagy-lysosomal pathway by phytochemicals: A potential therapeutic strategy against Alzheimer's disease

The lysosome is a membrane-enclosed organelle in eukaryotic cells, which has basic pattern recognition for nutrient-dependent signal transduction. In Alzheimer's disease, the already declining autophagy-lysosomal function is exacerbated by an increased need for clearance of damaged proteins and organelles in aged cells. Recent evidence suggests that numerous diseases are linked to impaired autophagy upstream of lysosomes. In this way, a comprehensive survey on the pathophysiology of the disease seems necessary. Hence, in the first section of this review, we will discuss the ultimate findings in lysosomal signaling functions and how they affect cellular metabolism and trafficking under neurodegenerative conditions, specifically Alzheimer's disease. In the second section, we focus on how natural products and their derivatives are involved in the regulation of inflammation and lysosomal dysfunction pathways, including how these should be considered a crucial target for Alzheimer's disease therapeutics.

Foods with Potential Prooxidant and Antioxidant Effects Involved in Parkinson's Disease

Oxidative stress plays a fundamental role in the pathogenesis of Parkinson's disease (PD). Oxidative stress appears to be responsible for the gradual dysfunction that manifests via numerous cellular pathways throughout PD progression. This review will describe the prooxidant effect of excessive consumption of processed food. Processed meat can affect health due to its high sodium content, advanced lipid oxidation end-products, cholesterol, and free fatty acids. During cooking, lipids can react with proteins to form advanced end-products of lipid oxidation. Excessive consumption of different types of carbohydrates is a risk factor for PD. The antioxidant effects of some foods in the regular diet provide an inconclusive interpretation of the environment's mechanisms with the modulation of oxidation stress-induced PD. Some antioxidant molecules are known whose primary mechanism is the neuroprotective effect. The melatonin mechanism consists of neutralizing reactive oxygen species (ROS) and inducing antioxidant enzyme's expression and activity. N-acetylcysteine protects against the development of PD by restoring levels of brain glutathione. The balanced administration of vitamin B3, ascorbic acid, vitamin D and the intake of caffeine every day seem beneficial for brain health in PD. Excessive chocolate intake could have adverse effects in PD patients. The findings reported to date do not provide clear benefits for a possible efficient therapeutic intervention by consuming the nutrients that are consumed regularly.

Special bioactive compounds and functional foods may exhibit neuroprotective effects in patients with dementia (Review)

Dementia is a failure of cognitive ability characterized by severe neurodegeneration in select neural systems, and Alzheimer's disease (AD) is the most common type of neurodegenerative disease. Although numerous studies have provided insights into the pathogenesis of AD, the underlying signaling and molecular pathways mediating the progressive decline of cognitive function remain poorly understood. Recent progress in molecular biology has provided an improved understanding of the importance of molecular pathogenesis of AD, and has proposed an association between DNA repair mechanisms and AD. In particular, the fundamental roles of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) and breast cancer gene 1 (BRCA1) tumor suppressors have been shown to regulate the pathogenesis of neurodegeneration. Consequently, onset of neurodegenerative diseases may be deferred with the use of dietary neuroprotective agents which alter the signaling mediated by the aforementioned tumor suppressors. In a healthy neuron, homeostasis of key intracellular molecules is of great importance, and preventing neuronal apoptosis is one of the primary goals of treatments designed for dementia-associated diseases. In the present review, progress into the understanding of dietary regulation for preventing or limiting development of dementia is discussed with a focus on the modulatory roles of PTEN and BRCA1 signaling.

Cigarette smoke promotes chronic obstructive pulmonary disease (COPD) through the miR-130a/Wnt1 axis

Cigarette smoke (CS) is a crucial factor in chronic obstructive pulmonary disease (COPD). Wnt/β-catenin signaling deregulation may further contribute to COPD progression. The deregulation and dysfunction of miRNAs in COPD have been reported. Investigating the deregulated miRNAs and their potential role in COPD progression may provide novel strategies for COPD treatment. In the present study, we analyzed significantly differentially-expressed miRNAs in COPD according to GSE44531 and miR-130a was selected. We revealed the upregulation of miR-130a in COPD, both in cigarette smoke extract (CSE)-treated BEAS-2B cells and CS-exposed mice. MiR-130a negatively regulated three critical factors in Wnt/β-catenin signaling, Wnt1, β-Catenin, and LEF1. MiR-130a inhibition rescued CSE-blocked activation of Wnt/β-catenin signaling in vitro. MiR-130a targets WNT1 3'UTR to inhibit its expression. Moreover, in CSE-stimulated BEAS-2B cells, miR-130a overexpression aggravated, while miR-130a inhibition partially attenuated CSE-caused suppression on cell migration and proliferation. MiR-130a aggravates CSE-induced cellular injury in BEAS-2B cells by targeting Wnt signaling. In summary, miR-130a has a pathogenetic role in CS-induced COPD and regulates Wnt/β-catenin signaling via targeting Wnt1. Our findings indicate that miR-130a is a potential therapeutic target for the treatment of CS-induced COPD.