The ethanolic extract of Aralia continentalis ameliorates cognitive deficits via modifications of BDNF expression and anti-inflammatory effects in a rat model of post-traumatic stress disorder

A Comprehensive Review of Traditional Medicinal Uses, Geographical Distribution, Botanical Characterization, Phytochemistry, and Pharmacology of Aralia continentalis Kitag

Aralia continentalis Kitag. (A. continentalis) holds significant medicinal value among the Aralia genus. It has traditionally been employed in ethnomedicine to address a wide range of conditions, including wind-cold-dampness arthralgia; rheumatic pain in the waist and lower extremities; lumbar muscular strain; injuries resulting from falls, fractures, contusions, and strains; headache; toothache; and abscesses. Modern pharmacological research has validated its therapeutic potential, encompassing anti-inflammatory, analgesic, antioxidant, antimicrobial, insecticidal, hepatoprotective, anti-diabetic, and cytotoxic properties, among other pharmacological effects. To compile comprehensive knowledge on A. continentalis, a rigorous literature search was undertaken utilizing databases like SciFinder, PubMed, and Web of Science. This review seeks to delve into the plant's traditional applications, geographical distribution, botanical characteristics, phytochemistry, and pharmacology. The objective is to lay a foundation and propose novel research directions for exploring the plant's potential applications. Currently, one hundred and fifty-nine compounds have been isolated and identified from A. continentalis, encompassing diterpenoids, steroids, triterpenoids, volatile components, phenolics, vitamins, trace elements, and other compounds. Notably, diterpenoids, steroids, triterpenoids, volatile components, and phenolics have exhibited pronounced pharmacological effects, such as anti-inflammatory, analgesic, antioxidant, hepatoprotective, antidiabetic, and antimicrobial activities. However, despite the extensive research conducted, further studies are imperative to unravel new components and mechanisms of action, necessitating more in-depth investigations. This comprehensive exploration could pave the way for advancing and harnessing the potential of A. continentalis.

Medicinal cannabis oil improves anxiety-like and depressive-like behaviors in CCS mice via the BDNF/TRPC6 signaling pathway

BACKGROUND

Post-traumatic stress disorder (PTSD) refers to a chronic impairing psychiatric disorder occurring after exposure to the severe traumatic event. Studies have demonstrated that medicinal cannabis oil plays an important role in neuroprotection, but the mechanism by which it exerts anti-PTSD effects remains unclear.

METHODS

The chronic complex stress (CCS) simulating the conditions of long voyage stress for 4 weeks was used to establish the PTSD mice model. After that, behavioral tests were used to evaluate PTSD-like behaviors in mice. Mouse brain tissue index was detected and hematoxylin-eosin staining was used to assess pathological changes in the hippocampus. The indicators of cell apoptosis and the BDNF/TRPC6 signaling activation in the mice hippocampus were detected by western blotting or real-time quantitative reverse transcription PCR experiments.

RESULTS

We established the PTSD mice model induced by CCS, which exhibited significant PTSD-like phenotypes, including increased anxiety-like and depression-like behaviors. Medicinal cannabis oil treatment significantly ameliorated PTSD-like behaviors and improved brain histomorphological abnormalities in CCS mice. Mechanistically, medicinal cannabis oil reduced CCS-induced cell apoptosis and enhanced the activation of BDNF/TRPC6 signaling pathway.

CONCLUSIONS

We constructed a PTSD model with CCS and medicinal cannabis oil that significantly improved anxiety-like and depressive-like behaviors in CCS mice, which may play an anti-PTSD role by stimulating the BDNF/TRPC6 signaling pathway.

Aralia continentalis Root Enhances Non-Rapid Eye Movement Sleep by Activating GABAA Receptors

Aralia continentalis exhibits various biological activities; however, their sleep-promoting effects have not been previously reported. In this study, we evaluated the hypnotic effects and sleep-wake profiles of A. continentalis root (KS-126) using a pentobarbital-induced sleep-acceleration test and polysomnographic recordings. Additionally, we investigated the molecular mechanism of KS-126 through patch-clamp electrophysiology. Our polysomnographic recordings revealed that KS-126 not only accelerated the onset of non-rapid eye movement sleep (NREMS) but also extends its duration. Considering the temporal dynamics of the sleep-wake stages, during the initial and subsequent periods KS-126 extended NREMS duration and decreased wakefulness, thereby enhancing sleep-promoting effects. Furthermore, the assessment of sleep quality via analysis of electroencephalogram power density indicated that KS-126 did not significantly alter sleep intensity. Finally, we found that KS-126 enhanced GABAA receptor-mediated synaptic responses in primary hippocampal neurons, leading to an increase in the percentage of the GABA current. This effect was not affected by the selective benzodiazepine receptor antagonist flumazenil, but was entirely inhibited by the GABAA receptor antagonist bicuculline. In conclusion, KS-126 extends the duration of NREMS without altering its intensity by prolonging GABAergic synaptic transmission, which modulates GABAA receptor function.

Phytochemical interventions for post-traumatic stress disorder: A cluster co-occurrence network analysis using CiteSpace

OBJECTIVE

This study investigated trends in the study of phytochemical treatment of post-traumatic stress disorder (PTSD).

METHODS

The Web of Science database (2007-2022) was searched using the search terms "phytochemicals" and "PTSD," and relevant literature was compiled. Network clustering co-occurrence analysis and qualitative narrative review were conducted.

RESULTS

Three hundred and one articles were included in the analysis of published research, which has surged since 2015 with nearly half of all relevant articles coming from North America. The category is dominated by neuroscience and neurology, with two journals, Addictive Behaviors and Drug and Alcohol Dependence, publishing the greatest number of papers on these topics. Most studies focused on psychedelic intervention for PTSD. Three timelines show an "ebb and flow" phenomenon between "substance use/marijuana abuse" and "psychedelic medicine/medicinal cannabis." Other phytochemicals account for a small proportion of the research and focus on topics like neurosteroid turnover, serotonin levels, and brain-derived neurotrophic factor expression.

CONCLUSION

Research on phytochemicals and PTSD is unevenly distributed across countries/regions, disciplines, and journals. Since 2015, the research paradigm shifted to constitute the mainstream of psychedelic research thus far, leading to the exploration of botanical active ingredients and molecular mechanisms. Other studies focus on anti-oxidative stress and anti-inflammation. Please cite this article as: Gao B, Qu YC, Cai MY, Zhang YY, Lu HT, Li HX, Tang YX, Shen H. Phytochemical interventions for post-traumatic stress disorder: A cluster co-occurrence network analysis using CiteSpace. J Integr Med. 2023; Epub ahead of print.

Analysis of Structure and Antioxidant Activity of Polysaccharides from Aralia continentalis

We extracted, purified, and characterized three neutral and three acidic polysaccharides from the roots, stems, and leaves of Aralia continentalis Kitigawa. The results of the analysis of monosaccharide composition indicated that the polysaccharides from the roots and stems were more similar to each other than they were to the polysaccharides from the leaves. The in vitro antioxidant results demonstrated that the acidic polysaccharides had stronger antioxidant activity than the neutral fractions. Therefore, we investigated the primary purified acidic polysaccharide fractions (WACP(R)-A-c, WACP(S)-A-c, and WACP(L)-A-d) by NMR and enzymatic analysis. The structural analytical results indicated that WACP(R)-A-c contained homogalacturonan (HG); WACP(S)-A-c contained HG and rhamnogalacturonan II (RG-II), and WACP(L)-A-d contained HG, RG-II, and rhamnogalacturonan I (RG-I) domains. Our findings offer insights into the screening of natural polysaccharide-based antioxidants and provide a theoretical basis for the application of A. continentalis.

Anti-Inflammatory Effects of Aralia elata Extract Against Dextran Sodium Sulfate-Induced Colitis in Mice and Raw 264.7 Macrophage Cells Exposed to Lipopolysaccharide: First Report

Aralia elata (AE) is an anti-inflammatory, polyphenolic containing medicinal plant. However, little is known about AE and its application to ulcerative colitis (UC). This study aimed to confirm AE extract's antioxidant and anti-inflammatory effects in vivo and in vitro. The in vitro antioxidant activity was evaluated by measuring total polyphenol and flavonoid content in AE extract. AE extract (10 000 mg/L) contained 186.8 mg GAE/g polyphenol and 81.9 mg QE/g flavonoid. Mice were divided into 6 groups, including control, which received normal saline, and treatment groups, which received dextran sodium sulfate (DSS) with or without AE extract (250, 500, and 1000 mg/kg). RAW 264.7 macrophage cells were divided into 2 groups: control and treatment. RAW 264.7 macrophage cells treated with sterile double distilled water, 1 mg/L lipopolysaccharide (LPS), and AE extracts (25, 50, 75, 100 µg/mL) were used to assess the cytotoxicity and anti-inflammatory activity. High-performance liquid chromatography, enzyme-linked immunosorbent assay (ELISA) kits, and histology were employed to analyze the AE extract contents, nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6, as oxidative stress markers. In addition, the disease activity index (DAI) and cytotoxicity were determined in mice and cells, respectively. High-performance liquid chromatography analysis revealed that AE extract is rich in chlorogenic acid (96 ± 0.01 mg/g). DSS increased the DAI and levels of TNF-α, IL-1β, and immune cell infiltration compared with those of the control animals. Furthermore, LPS eventually reduced cell viability and increased the levels of NO, TNF-α, IL-1β, and IL-6 in contrast to control cells. After treatment, a noticeable reduction was observed in the levels of DAI, NO, TNF-α, IL-1β, and IL-6 compared to those without AE treatments. Overall, AE extract is safe and had anti-inflammatory properties. Therefore, AE extract can be considered a potential pre-treatment supplement for UC.

Nutraceutical Interventions for Post-Traumatic Stress Disorder in Animal Models: A Focus on the Hypothalamic–Pituitary–Adrenal Axis

Post-traumatic stress disorder (PTSD) occurs after exposure to traumatic events and is characterized by overwhelming fear and anxiety. Disturbances in the hypothalamic–pituitary–adrenal (HPA) axis are involved in the pathogenesis of mood disorders, including anxiety, PTSD, and major depressive disorders. Studies have demonstrated the relationship between the HPA axis response and stress vulnerability, indicating that the HPA axis regulates the immune system, fear memory, and neurotransmission. The selective serotonin reuptake inhibitors (SSRIs), sertraline and paroxetine, are the only drugs that have been approved by the United States Food and Drug Administration for the treatment of PTSD. However, SSRIs require long treatment times and are associated with lower response and remission rates; therefore, additional pharmacological interventions are required. Complementary and alternative medicine therapies ameliorate HPA axis disturbances through regulation of gut dysbiosis, insomnia, chronic stress, and depression. We have described the cellular and molecular mechanisms through which the HPA axis is involved in PTSD pathogenesis and have evaluated the potential of herbal medicines for PTSD treatment. Herbal medicines could comprise a good therapeutic strategy for HPA axis regulation and can simultaneously improve PTSD-related symptoms. Finally, herbal medicines may lead to novel biologically driven approaches for the treatment and prevention of PTSD.

Tanshinone IIA improves contextual fear- and anxiety-like behaviors in mice via the CREB/BDNF/TrkB signaling pathway

Posttraumatic stress disorder (PTSD) is one of the most common psychiatric diseases, which is characterized by the typical symptoms such as re-experience, avoidance, and hyperarousal. However, there are few drugs for PTSD treatment. In this study, conditioned fear and single-prolonged stress were employed to establish PTSD mouse model, and we investigated the effects of Tanshinone IIA (TanIIA), a natural product isolated from traditional Chinese herbal Salvia miltiorrhiza, as well as the underlying mechanisms in mice. The results showed that the double stress exposure induced obvious PTSD-like symptoms, and TanIIA administration significantly decreased freezing time in contextual fear test and relieved anxiety-like behavior in open field and elevated plus maze tests. Moreover, TanIIA increased the spine density and upregulated synaptic plasticity-related proteins as well as activated CREB/BDNF/TrkB signaling pathway in the hippocampus. Blockage of CREB remarkably abolished the effects of TanIIA in PTSD model mice and reversed the upregulations of p-CREB, BDNF, TrkB, and synaptic plasticity-related protein induced by TanIIA. The molecular docking simulation indicated that TanIIA could interact with the CREB-binding protein. These findings indicate that TanIIA ameliorates PTSD-like behaviors in mice by activating the CREB/BDNF/TrkB pathway, which provides a basis for PTSD treatment.

Role of CRF and the hypothalamic-pituitary-adrenal axis in stroke: revisiting temporal considerations and targeting a new generation of therapeutics

Ischaemic neurovascular stroke represents a leading cause of death in the developed world. Preclinical and human epidemiological evidence implicates the corticotropin-releasing factor (CRF) family of neuropeptides as mediators of acute neurovascular injury pathology. Preclinical investigations of the role of CRF, CRF receptors and CRF-dependent activation of the hypothalamic-pituitary-adrenal (HPA) axis have pointed toward a tissue-specific and temporal relationship between activation of these pathways and physiological outcomes. Based on the literature, the major phases of ischaemic stroke aetiology may be separated into an acute phase in which CRF and anti-inflammatory stress signalling are beneficial and a chronic phase in which these contribute to neural degeneration, toxicity and apoptotic signalling. Significant gaps in knowledge remain regarding the pathway, temporality and systemic impact of CRF signalling and stress biology in neurovascular injury progression. Heterogeneity among experimental designs poses a challenge to defining the apparent reciprocal relationship between neurological injury and stress metabolism. Despite these challenges, it is our opinion that the elucidated temporality may be best matched with an antibody against CRF with a half-life of days to weeks as opposed to minutes to hours as with small-molecule CRF receptor antagonists. This state-of-the-art review will take a multipronged approach to explore the expected potential benefit of a CRF antibody by modulating CRF and corticotropin-releasing factor receptor 1 signalling, glucocorticoids and autonomic nervous system activity. Additionally, this review compares the modulation of CRF and HPA axis activity in neuropsychiatric diseases and their counterpart outcomes post-stroke and assess lessons learned from antibody therapies in neurodegenerative diseases.

A prognostic study on the effect of post-traumatic stress disorder on cerebral ischaemia reperfusion-induced stroke

OBJECTIVES

Previous studies have been established that persons who experienced a stroke are soon likely to develop several anxiety disorders. In which one of the major anxiety disorders is Post-traumatic Stress Disorder (PTSD). Yet, the likelihood of PTSD in conjunction with cerebral stroke has not been well described. Hence, we evaluated the impact of PTSD on cerebral stroke in rodents subjected to single prolonged stress (SPS) and bilateral common carotid artery occlusion (BCCAo), respectively.

METHODS

The relation between PTSD and cerebral stroke is evaluated by performing behavioural, biochemical, histopathological, and brain lesion area measurement studies.

RESULTS

Interestingly, SPS + BCCAo induction increased behavioural abnormalities like cognitive impairment and anxiety-like behaviour compared to SPS and BCCAo groups alone. Motor impairment was also observed in SPS + BCCAo rats compared to SPS rats, whereas no change with BCCAo rats. Furthermore, increased brain tissue MDA, acetylcholinesterase, and decreased SOD, catalase, and GSH were observed in SPS + BCCAo subjected rats compared to SPS and BCCAo rats alone. Additionally, SPS + BCCAo induction considerably increased the plasma corticosterone levels and caused severe neurotransmitter alterations. The SPS + BCCAo exposure significantly increased the brain lesion area in comparison with BCCAo rats. Moreover, severe histopathological alterations were observed in the hippocampus (CA1) of SPS + BCCAo rats compared to SPS and BCCAo rats alone.

CONCLUSIONS

In conclusion, our study results suggested that SPS-induced PTSD may aggravate the BCCAo induced cerebral ischaemia-reperfusion injury.

Anticancer Activity of Continentalic Acid in B-Cell Lymphoma

Aralia continentalis has been used in Korea as a folk remedy for arthralgia, rheumatism, and inflammation. However, its anti-lymphoma effect remains uncharacterized. Here, we demonstrate that A. continentalis extract and its three diterpenes efficiently kill B-lymphoma cells. Our in vitro and in vivo results suggest that the cytotoxic activities of continentalic acid, a major diterpene from A. continentalis extract, are specific towards cancer cells while leaving normal murine cells and tissues unharmed. Mechanistically, continentalic acid represses the expression of pro-survival Bcl-2 family members, such as Mcl-1 and Bcl-xL. It dissociates the mitochondrial membrane potential, leading to the stimulation of effector caspase 3/7 activities and, ultimately, cell death. Intriguingly, this agent therapeutically synergizes with roflumilast, a pan-PDE4 inhibitor that has been successfully repurposed for the treatment of aggressive B-cell malignancies in recent clinical tests. Our findings unveiled that A. continentalis extract and three of the plant’s diterpenes exhibit anti-cancer activities. We also demonstrate the synergistic inhibitory effect of continentalic acid on the survival of B-lymphoma cells when combined with roflumilast. Taken in conjunction, continentalic acid may hold significant potential for the treatment of B-cell lymphoma.

Neuroprotective effect of Korean red ginseng against single prolonged stress-induced memory impairments and inflammation in the rat brain associated with BDNF expression

Background

Post-traumatic stress disorder (PTSD) is a psychiatric disease that develops following exposure to a traumatic event and is a stress-associated mental disorder characterized by an imbalance of neuroinflammation. Korean Red Ginseng (KRG) is the herbal supplement that is known to be involved in a variety of pharmacological activities. We aimed to investigate the effects of KRG on neuroinflammation as a potential mechanism involved in single prolonged stress (SPS) that negatively influences memory formation and consolidation and leads to cognitive and spatial impairment by regulating BDNF signaling, synaptic proteins, and the activation of NF-kB.

Methods

We analyzed the cognitive and spatial memory, and inflammatory cytokine levels during the SPS procedure. SPS model rats were injected intraperitoneally with 20, 50, or 100 mg/kg/day KRG for 14 days.

Results

KRG administration significantly attenuated the cognitive and spatial memory deficits, as well as the inflammatory reaction in the hippocampus associated with activation of NF-κB in the hippocampus induced by SPS. Moreover, the effects of KRG were equivalent to those exerted by paroxetine. In addition, KRG improved the expression of BDNF mRNA and the synaptic protein PSD-95 in the hippocampus. Taken together, these findings demonstrate that KRG exerts memory-improving actions by regulating anti-inflammatory activities and the NF-κB and neurotrophic pathway.

Conclusion

Our findings suggest that KRG is a potential functional ingredient for protecting against memory deficits in mental diseases, such as PTSD.

Augmented Buyang Huanwu Decoction facilitates axonal regeneration after peripheral nerve transection through the regulation of inflammatory cytokine production

ETHNOPHARMACOLOGICAL RELEVANCE

Herbal formulation Buyang Huanwu Decoction (BYHWD) has been used to treat cardiovascular disorders including cerebral ischemia. Recent studies showed its effects on promoting axonal regeneration after nerve injury. However, compositional reformulation supplemented with herbal components that regulates inflammation may increase its efficacy for nerve repair.

AIM OF THE STUDY

We prepared a new herbal decoction by adding selected herbal components to BYHWD (augmented BYHWD; ABHD) and investigated the effect of ABHD on the production of inflammatory cytokines and axonal regeneration using an animal model of nerve transection and coaptation (NTC).

MATERIALS AND METHODS

A rat model of NTC was performed on the sciatic nerve. The sciatic nerve and dorsal root ganglion (DRG) were isolated and used for immunofluorescence staining and western blot analysis. DRG tissue was also used to prepare primary neuron culture and the length of neurites was analyzed. Sensorimotor nerve activities were assessed by rotarod and von Frey tests.

RESULTS

Three herbal components that facilitated neurite outgrowth were chosen to formulate ABHD. ABHD administration into the sciatic nerve 1 week or 3 months after NTC facilitated axonal regeneration. Cell division cycle 2 (Cdc2) and brain-derived neurotrophic factor (BDNF) proteins were induced from the reconnected distal portion of the sciatic nerve and the levels were further elevated by in vivo administration of ABHD. Phospho-Erk1/2 level was increased by ABHD treatment as well, implying its role in mediating retrograde transport of BDNF signals into the neuronal cell body. Production of inflammatory cytokines IL-1β and TNF-α was induced in the reconnected nerve but attenuated by ABHD treatment. Behavioral tests revealed that ABHD treatment improved functional recovery of sensorimotor activities.

CONCLUSIONS

A newly formulated ABHD is effective at regulating the production of inflammatory cytokines and promoting axonal regeneration after nerve transection and may be considered to develop therapeutic strategies for peripheral nerve injury disorders.

Long-Term Effect of Post-traumatic Stress in Adolescence on Dendrite Development and H3K9me2/BDNF Expression in Male Rat Hippocampus and Prefrontal Cortex

Exposure to a harsh environment in early life increases in the risk of post-traumatic stress disorder (PTSD) of an individual. Brain derived neurotrophic factor (BDNF) plays an important role in neurodevelopment in developmental stages. Both chronic and traumatic stresses induce a decrease in the level of BDNF and reduce neural plasticity, which is linked to the pathogenesis of PTSD. Also, studies have shown that stress alters the epigenetic marker H3K9me2, which can bind to the promoter region of the Bdnf gene and reduce BDNF protein level. However, the long-term effects of traumatic stress during adolescence on H3K9me2, BDNF expression and dendrite development are not well-known. The present study established a model of PTSD in adolescent rats using an inescapable foot shock (IFS) procedure. Anxiety-like behaviors, social interaction behavior and memory function were assessed by the open field test, elevated plus maze test, three-chamber sociability test and Morris water maze test. In addition, neuronal development and H3K9me2/BDNF expression in hippocampus (HIP) and prefrontal cortex (PFC) were evaluated by Golgi staining, western blotting, qRT-PCR analysis and CHIP-qPCR analysis. Additionally, the Unc0642, a small molecule inhibitor of histone methyltransferase (EHMT2) was used for intervention. The results showed that the IFS procedure induced the PTSD-like behaviors in rats, resulted in fewer dendrite branches and shorter dendrite length in CA1 of HIP and PFC, increased H3K9me2 level and decreased BDNF expression in HIP and PFC. Also, although all the changes can persist to adulthood, Unc0642 administration relieved most of alterations. Our study suggests that traumatic stress in adolescence leads to immediate and long-term mental disorders, neuronal morphological changes, lower BDNF level and increased H3K9me2 level in the HIP and PFC, indicating that H3K9me2/BDNF dysfunction plays a key role in pathogenesis of PTSD.

Effect of alcohol tincture of Aralia elata on the organism of rats and their gut microbiota against the background of excessive fat diet

Pharmacological effects of the medicinal plant Aralia elata (Miq.) Seem. 1868 (Araliaceae) are related to presence of over 150 secondary metabolites, including flavonoids, sterols, polysaccharides, terpenoid saponins and terpenoid acids, though the main biologically active substances of A. elata are saponins and flavonoids. Some clinical tests and experimental studies have proved the influence of A. elata on the organism through increase in physical work capacity, exerting an anti-stress effect against a broad range of harmful factors, including stress from cold, immobilization, ultraviolet radiation and low pressure. The literature also reports the anti-ulcer, anti-secretory, antifungal, anti-tumour, and antimicrobial activity of preparations from this plant. In our laboratory experiment, we determined that ethanolic tincture of A. elata has no effect on the intensity of growth of body weight of young rats against the background of excessive content of fat in their diet. Excessive fat-feeding of male rats leads mostly to disorders in the functioning of the liver and development of steatosis. This was accompanied by reduction in relative mass of the liver, increase in activity of hepatic enzymes, dysproteinemia, increase in the level of bilirubin and decrease in the level of urea. Additional use of 0.1% ethanol led to impaired functioning of the kidneys, reduction of their relative mass, signs of dehydration, increase in the level of creatinine and total calcium in the blood. Use of ethanolic tincture of A. elata mitigates negative excess of fat, is accompanied by normalization of indices of mass of the organs, less notable dysproteinemia, impairment in the level of creatinine, glucose, urea, cholesterol, bilirubin and total calcium. Ethanolic tincture of A. elata has a low immunosuppressive action, against the background of a high fat diet it leads to increase in the amount of typical Escherichia сoli, decrease in Еnterococcus spp. and Enterobacter spp., significant decrease and in high concentrations (0.1% ethanolic tincture of A. elata) elimination of bacteria of Clostridium and Klebsiella genera, and also various yeast fungi in the intestine. In the examined male rats, against the background of excess of fat in the diet, no serious changes in the composition of the normal gut microbiota (Bifidobacterium spp., Lactobacillus spp., Proteus spp., Staphylococcus spp., Candida spp.) was observed, nor were any lactose-negative enterobacteria (Citrobacter genus) found. Perspectives of further research include determining histological, histochemical and immune-histological changes in the organs of laboratory animals under the effect of ethanolic tincture of A. elata following excessive accumulation of fat.

Involvement of calcineurin/NFATc4 pathway in a single-prolonged stress-based rat model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a mental disease associated with the exposure of traumatic stress, and results in the structural and functional changes of hippocampus. Calcineurin (CaN), a calcium/calmodulin-regulated protein phosphatase ubiquitously expressed in brain, has a very important role in the fear extinction, neuronal structure and neuronal excitability. With CaN activation, its down target nuclear factor of activated T cells (NFATs) dephosphorylated and then translocated from the cytoplasm to the nucleus to affect neuronal function, resulting in the function changes of brain structure such as hippocampus. Increasing evidence has suggested that CaN/NFATs signaling are involved in the regulation of mental disorders like Alzheimer's disease, depression, while little is known about its effects on the molecular mechanisms on PTSD. This study seek to know the relationship between PTSD and CaN/NFATc4 pathway, and to detect whether CaN/NFATc4 pathway are involved in the hippocampus dysfunctions in a single-prolonged stress (SPS)-based rat model of PTSD. Our results have showed that after 4 days exposed to SPS, the protein expression of CaN up-regulated and the NFATc4 dephosphorylated and imported into the nucleus; while at the 7 and 14 day exposed to SPS, with the down-regulation of CaN, the expression of phosphorylate-NFATc4 increased. Our results show that CaN/NFATc4 pathway were involved in the development of PTSD model, which suggested that the changes of CaN/NFATc4 pathway may be one of the pathological molecular mechanism in the dysfunction of hippocampus in PTSD.