Ginsenoside Rg3 modulates spatial memory and fear memory extinction by the HPA axis and BDNF-TrkB pathway in a rat post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a serious mental disorder that can develop after exposure to extreme stress. Korean red ginseng, whose major active component is ginsenoside Rg3 (Rg3), is a widely used traditional antioxidant that has anti-inflammatory, anti-apoptotic and anxiolytics effects. This study investigated whether the administration of Rg3 ameliorated the memory deficit induced by a single prolonged stress (SPS) in rats. Male rats were dosed with Rg3 (25 or 50 mg/kg) once daily for 14 days after exposure to SPS. Rg3 administration improved fear memory and spatial memory might be involved in modulating the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and monoamine imbalance in the medial prefrontal cortex and hippocampus. It also increased the reduction in the brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) mRNAs expression, and the ratio of p-Akt/Akt in the hippocampus. Thus, Rg3 exerted memory-improving actions might be involved in regulating HPA axis and activating BDNF-TrkB pathway. Our findings suggest that Rg3 could be useful for preventing traumatic stress, such as PTSD.

Myricetin Inhibited Fear and Anxiety-Like Behaviors by HPA Axis Regulation and Activation of the BDNF-ERK Signaling Pathway in Posttraumatic Stress Disorder Rats.

Posttraumatic stress disorder (PTSD) is a stress-related psychiatric or mental disorder characterized by experiencing a traumatic stress. The cause of such PTSD is dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and imbalance of monoamines. Myricetin (MYR) is a common natural flavonoid that has various pharmacological activities. We investigated the effects of MYR on fear, depression, and anxiety following monoamine imbalance and hyperactivation of HPA axis in rats exposed to a single prolonged stress (SPS). Male rats were dosed with MYR (10 and 20 mg/kg, i.p.) once daily for 14 days after exposure to SPS. Administration of MYR reduced freezing responses to extinction recall, depression, and anxiety-like behaviors and decreased increase of plasma corticosterone and adrenocorticotropic hormone levels. Also, administration of MYR restored decreased serotonin and increased norepinephrine in the fear circuit regions, medial prefrontal cortex, and hippocampus. It also increased the reduction in the brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B mRNA expression and the ratio of p-ERK/extracellular signal-regulated kinase (ERK) in the hippocampus. Thus, MYR exerted antidepressant and anxiolytic effects by regulation of HPA axis and activation of the BDNF-ERK signaling pathway. Finally, we suggest that MYR could be a useful therapeutic agent to prevent traumatic stress such as PTSD.

The Anxiolytic-Like Effects of Protocatechuic Acid in an Animal Model of Post-Traumatic Stress Disorder.

Post-traumatic stress disorder (PTSD) is a serious psychiatric disorder characterized by impaired fear extinction, depression, and anxiety caused by dysregulation of the hypothalamic-pituitary-adrenal axis and an imbalance of monoamines. Protocatechuic acid (PCA; 3,4-dihydroxybenzoic acid), a major polyphenol metabolite, has various pharmacological effects, such as anti-inflammatory, antioxidant, anti-apoptotic, and neuroprotective activities. In this study, the efficacy of PCA for fear extinction, antidepressant, and anxiolytic effects in PTSD-mediated psychiatric disorders, were evaluated by exposing rats to single prolonged stress (SPS). Male rats were administered PCA (100 or 200 mg/kg) once daily for 14 days after exposure to SPS. PCA significantly decreased situational fear, depressive and anxiety-like behaviors, and corticosterone levels. In addition, PCA regulated the imbalance of serotonin and norepinephrine in the fear circuit region (i.e., the medial prefrontal cortex and hippocampus [Hipp]), and suppressed the decrease in brain-derived neurotrophic factor mRNA expression in the Hipp. The results showed that PCA administration improves freezing behavior and has antidepressant and anti-anxiety effects through modulation of the serotonergic nervous system and monoamines in rats. These results indicated that PCA may be useful as a food ingredient to prevent PTSD.

Antidepressant-Like Effects of Hesperidin in Animal Model of Post-Traumatic Stress Disorder.

OBJECTIVE: Post-traumatic stress disorder (PTSD) is a psychiatric disorder characterized by depression and anxiety, that arises due to an imbalance of neurotransmitters in response to excessive stress. Hesperidin (HSD) is a naturally occurring flavonoid shown to exert a variety of biological activities, including antioxidant, anti-inflammatory, and neuroprotective effects. METHODS: This study was used the open field test (OFT) and forced swimming test (FST) to examine the effects of HSD on the depression-like response of rats after exposure to a single prolonged stress (SPS) leading to the dysregulation of the serotonergic activation system. Male rats were given HSD (20, 50, and 100 mg/kg, intraperitoneal injection, n=6-7 per group) once daily for 14 days after exposure to SPS. The influence of administration of HSD on SPS-induced behavioral responses and concentrations of serotonin (5-HT), 5-hydroxyindoleacetic acid (5-HIAA), and monoamine oxidase-A (MAO-A) in the rat brain were also investigated using enzyme-linked immunoassays (ELISAs). RESULTS: Daily HSD administration signifificantly improved depression-like behaviors in the FST (P0.05), increased the number of lines crossed in the central zone of the OFT (P0.01), and reduced freezing behavior both in contextual and cued fear conditioning. HSD treatment also attenuated the reduction in SPS-induced 5-HT concentrations in the hippocampus and amygdala. This increase in 5-HT concentrations during HSD treatment was partially attributed to a decrease in the 5-HIAA/5-HT ratio in the hippocampus of rats with PTSD. Furthermore, HSD treatment inhibited activity of MAO-A and decreases of tryptophan hydroxylase-1 expression in the hippocampus. CONCLUSION: HSD was shown to exert antidepressant effects in rats exposed to SPS, suggesting that this natural flflavonoid may be an effective medicine for PTSD.

Korean Red Ginseng prevents posttraumatic stress disorder-triggered depression-like behaviors in rats via activation of the serotonergic system.

BACKGROUND: Posttraumatic stress disorder (PTSD), a mental disorder induced by traumatic stress and often accompanied by depression and/or anxiety, may involve an imbalance in the neurotransmitters associated with the fear response. Korean Red Ginseng (KRG) has long been used as a traditional medicine and is known to be involved in a variety of pharmacological activities. We used the open field test and forced swimming test to examine the effects of KRG on the depression-like response of rats after exposure to single prolonged stress (SPS), leading to activation of the serotonergic system. METHODS: Male rats received KRG (30, 50, and 100 mg/kg, intraperitoneal injection) once daily for 14 days after exposure to SPS. RESULTS: Daily KRG administration significantly improved depression-like behaviors in the forced swimming test, increased the number of lines crossed and time spent in the central zone in the open field test, and decreased freezing behavior in contextual and cued fear conditioning. KRG treatment attenuated SPS-induced decreases in serotonin (5-HT) tissue concentrations in the hippocampus and medial prefrontal cortex. The increased 5-HT concentration during KRG treatment may be partially attributable to the 5-hydroxyindoleacetic acid/5-HT ratio in the hippocampus of rats with PTSD. These effects may be caused by the activation of hippocampal genes encoding tryptophan hydroxylase-1 and 2 mRNA levels. CONCLUSION: Our findings suggest that KRG has an antidepressant effect in rats subjected to SPS and may represent an effective use of traditional medicine for the treatment of PTSD.

Inhibition of Carrageenan/Kaolin-Induced Arthritis in Rats and of Inflammatory Cytokine Expressions in Human IL-1ß-Stimulated Fibroblast-like Synoviocytes by a Benzylideneacetophenone Derivative.

The benzylideneacetophenone derivative JC3 [(2E)-3-(4-hydroxy-3-methoxyphenyl)phenylpro-2-en-l-one] (JC3) was synthesized by modifying yakuchinone B obtained from the seeds of Alpinia oxyphylla, a member of the ginger family (Zingiberaceae), which are widely used as a folk remedy and as an anti-inflammatory. The aim of this study was to investigate the anti-arthritic effects of JC3 in rat models of carrageenan-induced paw pain and carrageenan/kaolin-induced knee arthritis. The anti-nociceptive effect of JC3 was assessed by measuring paw withdrawal pressure thresholds using an analgesy-meter. Arthritic symptoms in our monoarthritic rat model were evaluated using weight distribution ratios (WDR), paw thicknesses, and serum prostaglandin E2 (PGE2), tumor necrosis factor (TNF)-α, interleukin (IL)-6, and vascular endothelial growth factor (VEGF) levels (determined by ELISA). Histological analyses of knee joints were performed after injecting JC3 intraperitoneally into rats before carrageenan treatment at 5 or 10 mg/kg/day for 6 days. The anti-inflammatory effects of JC3 were investigated in vitro using interleukin-1beta (IL-1ß)-stimulated fibroblast-like synoviocytes (FLS) derived from arthritis patients. PGE2, IL-6, and IL-8 levels were measured after treating FLS with JC3. In arthritis-induced rats, JC3 treatment significantly decreased nociceptive and arthritic symptoms at days 5 to 6 after carrageenan/kaolin injection. Histological staining of knee tissue showed that JC3 significantly reduced inflammatory areas in the knee joints. Furthermore, JC3 inhibited the expressions of IL-6 and IL-8 in FLS cells at concentrations of 5-10 µg/ml and decreased PGE2 levels in FLS cells. These findings suggest JC3 has anti-arthritic effects in in vivo and in vitro, and that it might be useful for the treatment of arthritis.

Anti-inflammatory and anti-arthritic effects of the ethanolic extract of Aralia continentalis Kitag. in IL-1ß-stimulated human fibroblast-like synoviocytes and rodent models of polyarthritis and nociception.

BACKGROUND: Blocking the formation and invasive growth of pannus and its secretion of inflammatory cytokines and MMPs is important for treating rheumatoid arthritis. HYPOTHESIS/PURPOSE: Anti-arthritic activity of Aralia continentalis Kitag., an oriental herbal medicine, and the underlying mechanisms involved were investigated. STUDY DESIGN: Anti-inflammatory and anti-nocicpetive activities of the ethanolic extract (50% v/v) of Aralia continentalis Kitag. harvested from Imsil, Korea (ACI) were investigated in IL-1ß-stimulated human fibroblast-like synoviocyte (FLS) cells and rodent models of collagen-induced polyarthritis and carrageenan-induced acute paw pain. METHODS: In IL-1ß-stimulated FLS cells derived from rheumatoid arthritis patients, the anti-inflammatory activity of ACI was examined by analyzing the expression levels of inflammatory mediators such as TNF-α, IL-6, IL-8, MMP-1, MMP-3, MMP-13, PGE2, and COX-2 using ELISA and RT-PCR analysis. The anti-arthritic activity of ACI was investigated by measuring body weight, squeaking score, paw volume, and arthritis index in collagen-induced polyarthritis mice. The anti-nociceptive activity of ACI was examined in the paw-pressure test and Tail-flick latency test in rats. RESULTS: The ethanolic extract (50% v/v) of ACI reduced the levels of TNF-α, IL-6, IL-8, MMP-1, and MMP-13 secreted by IL-1ß-stimulated FLS cells, whereas MMP-3, COX-2, and PGE2 were not significantly affected. ACI inhibited the migration of NF-κB into the nucleus through the inhibition of ERK- and JNK-dependent MAP kinase pathways in IL-1ß-stimulated FLS cells. In collagen-induced polyarthritis mice, oral administration of ACI extract (200 mg/kg) significantly alleviated arthritic behaviors. Histological observations of arthritic mouse knees were consistent with their behaviors. The anti-arthritic and anti-inflammatory activities of 200 mg/kg ACI extract were comparable to those of 10 mg/kg prednisolone when administered to mice. However, ACI administration did not significantly affect carrageenan-induced hyperalgesia or thermal nociception in rats. CONCLUSION: These results suggest that the ethanolic extract of ACI have significant anti-inflammatory and anti-arthritic effects in a rodent arthritis model and in IL-1ß-stimulated FLS cells. Thus, ACI may be a useful candidate for developing pharmaceuticals or dietary supplements for the treatment of inflammatory arthritis.

Extract of Polygala tenuifolia Alleviates Stress-Exacerbated Atopy-Like Skin Dermatitis through the Modulation of Protein Kinase A and p38 Mitogen-Activated Protein Kinase Signaling Pathway.

Atopic dermatitis (AD) and stress create a vicious cycle: stress exacerbates atopic symptoms, and atopic disease elicits stress and anxiety. Targeting multiple pathways including stress and allergic inflammation is, therefore, important for treating AD. In this study, we investigated the remedial value of Polygala tenuifolia Willd. (PTW) for treating immobilization (IMO) stress-exacerbated atopy-like skin dermatitis and its underlying mechanism. Trimellitic anhydride (TMA) was applied to dorsal skin for sensitization and subsequently both ears for eliciting T-cell-dependent contact hypersensitivity in mice, which underwent 2 h-IMO stress and PTW administration for the latter 6 and 9 days in the ear exposure period of TMA, respectively. To elicit in vitro degranulation of human mast cell line-1 (HMC-1), 10 µM substance P (SP) and 200 nM corticotrophin-releasing factor (CRF) were sequentially added with 48 h-interval. PTW extract (500 µg/mL) was added 30 min before CRF treatment. IMO stress exacerbated TMA-induced scratching behavior by 252%, and increased their blood corticosterone levels by two-fold. Treatment with 250 mg/kg PTW significantly restored IMO stress-exacerbated scratching behavior and other indicators such as skin inflammation and water content, lymph node weights, and serum histamine and immunoglobulin E (lgE) levels. Furthermore, it also reversed TMA-stimulated expression of tumor necrosis factor (TNF)-α and interleukin (IL)-4 mRNAs in ear tissues. PTW significantly inhibited SP/CRF-stimulated degranulation of HMC-1 cells, subsequent tryptase secretion, and protein kinase A (PKA) activity. PTW also selectively inhibited p38 mitogen-activated protein kinase (MAPK) phosphorylation in SP/CRF-treated HMC-1 cells. PTW significantly inhibited HMC-1 cell degranulation and alleviated IMO stress-exacerbated atopic dermatitis symptoms by modulating the PKA/p38 MAPK signaling pathway.

Gastrodin reversed the traumatic stress-induced depressed-like symptoms in rats.

Exposure to severe stress can lead to the development of neuropsychiatric disorders such as depression and post-traumatic stress disorder (PTSD) in at-risk individuals. Gastrodin (GAS), a primary constituent of an Oriental herbal medicine, has been shown to effectively treat various mood disorders. Thus, the present study aimed to determine whether GAS would ameliorate stress-associated depression-like behaviors in a rat model of single prolonged stress (SPS)-induced PTSD. Following the SPS procedure, rats received intraperitoneal administration of GAS (20, 50, or 100 mg/kg) once daily for 2 weeks. Subsequently, the rats performed the forced swimming test, and norepinephrine (NE) levels in the hippocampus were measured. Daily GAS (100 mg/kg) significantly reversed depression-like behaviors and restored SPS-induced increases in hippocampal NE concentrations as well as tyrosine hydroxylase expression in the locus coeruleus. Furthermore, the administration of GAS attenuated SPS-induced decreases in the hypothalamic expression of neuropeptide Y and the hippocampal mRNA expression of brain-derived neurotrophic factor. These findings indicate that GAS possesses antidepressant effects in the PTSD and may be an effective herbal preparation for the treatment of PTSD.

Bee venom acupuncture alleviates trimellitic anhydride-induced atopic dermatitis-like skin lesions in mice.

BACKGROUND: Bee venom acupuncture (BVA), a novel type of acupuncture therapy in which purified bee venom is injected into the specific acupuncture point on the diseased part of the body, is used primarily for relieving pain and other musculoskeletal symptoms. In the present study, therapeutic potential of BVA to improve atopic dermatitis, a representative allergic dysfunction, was evaluated in the mouse model of trimellitic anhydride (TMA)-induced skin impairment. METHODS: Mice were treated with 5% TMA on the dorsal flank for sensitization and subsequently treated with 2% TMA on the dorsum of both ears for an additional 12 days after a 3-day interval. From the 7(th) day of 2% TMA treatment, bilateral subcutaneous injection of BV (BV, 0.3 mg/kg) was performed daily at BL40 acupuncture points (located behind the knee) 1 h before 2% TMA treatment for 5 days. RESULTS: BVA treatment markedly inhibited the expression levels of both T helper cell type 1 (Th1) and Th2 cytokines in ear skin and lymph nodes of TMA-treated mice. Clinical features of AD-like symptoms such as ear skin symptom severity and thickness, inflammation, and lymph node weight were significantly alleviated by BV treatment. BV treatment also inhibited the proliferation and infiltration of T cells, the production of Th1 and Th2 cytokines, and the synthesis of interleukin (IL)-4 and immunoglobulin E (IgE)-typical allergic Th2 responses in blood. The inhibitory effect of BVA was more pronounced at BL40 acupoint than non-acupuncture point located at the base of the tail. CONCLUSIONS: These results indicate that BV injection at specific acupuncture points effectively alleviates AD-like skin lesions by inhibiting inflammatory and allergic responses in a TMA-induced contact hypersensitivity mouse model.

Ginsenoside Rb1 rescues anxiety-like responses in a rat model of post-traumatic stress disorder.

Single prolonged stress (SPS), a rat model of post-traumatic stress disorder (PTSD), induces alterations in the hypothalamic-pituitary-adrenal axis. Korean red ginseng, whose major active component is ginsenoside Rb1 (GRb1), is one of the widely used traditional anxiolytics. However, the efficacy of GRb1 in alleviating PTSD-associated anxiety-like abnormalities has not been investigated. The present study used several behavioral tests to examine the effects of GRb1 on symptoms of anxiety in rats after SPS exposure and on the central noradrenergic system. Male Sprague-Dawley rats received GRb1 (10 or 30 mg/kg, i.p., once daily) during 14 days of SPS. Daily GRb1 (30 mg/kg) administration significantly increased the number and duration of open-arm visits in the elevated plus maze (EPM) test, reduced the anxiety index, increased the risk assessment, reduced grooming behaviors in the EPM test, and increased the total number of line crossings of an open field after SPS. The higher dose of GRb1 also blocked SPS-induced decreases in hypothalamic neuropeptide Y expression, increases in locus coeruleus tyrosine hydroxylase expression, and decreases in hippocampal mRNA expression of brain-derived neurotrophic factor. These findings suggest that GRb1 has anxiolytic-like effects on both behavioral and biochemical symptoms similar to those observed in patients with PTSD.

Effect of Beta-Asarone on Impairment of Spatial Working Memory and Apoptosis in the Hippocampus of Rats Exposed to Chronic Corticosterone Administration.

ß-asarone (BAS) is an active component of Acori graminei rhizoma, a traditional medicine used clinically in treating dementia and chronic stress in Korea. However, the cognitive effects of BAS and its mechanism of action have remained elusive. The purpose of this study was to examine whether BAS improved spatial cognitive impairment induced in rats following chronic corticosterone (CORT) administration. CORT administration (40 mg/kg, i.p., 21 days) resulted in cognitive impairment in the avoidance conditioning test (AAT) and the Morris water maze (MWM) test that was reversed by BAS (200 mg/kg, i.p). Additionally, as assessed by immunohistochemistry and RT-PCR analysis, the administration of BAS significantly alleviated memory-associated decreases in the expression levels of brain-derived neurotrophic factor (BDNF) and cAMP-response element-binding protein (CREB) proteins and mRNAs in the hippocampus. Also, BAS administration significantly restored the expression of Bax and Bcl-2 mRNAs in the hippocampus. Thus, BAS may be an effective therapeutic for learning and memory disturbances, and its neuroprotective effect was mediated, in part, by normalizing the CORT response, resulting in regulation of BDNF and CREB functions and anti-apoptosis in rats.

Angelica gigas ameliorate depression-like symptoms in rats following chronic corticosterone injection.

BACKGROUND: Repeated injection of corticosterone (CORT) induces dysregulation in the hypothalamic-pituitary-adrenal (HPA) axis, resulting in depression. We examined the effects of Angelica gigas extract (AGN) treatment in a rat model of depressive and anxiety-like behaviors, induced by chronic CORT exposure. METHODS: Male rats received 10, 20, or 50 mg/kg AGN (i.p.) 30 min prior to a daily injection of CORT for 21 consecutive days. Activation of the HPA axis in response to the repeated CORT injections was confirmed by measuring serum levels of CORT and the expression of corticotropin-releasing factor in the hypothalamus. RESULTS: Daily AGN administration significantly reversed the depression and anxiety-like behavioral abnormalities. It also blocked increases in tyrosine hydroxylase expression in the locus coeruleus, and suppressed the decreased expression levels of brain-derived neurotrophic factor (BDNF) and its receptor TrkB mRNAs in the hippocampus. CONCLUSIONS: These findings indicate that administration of AGN prior to high-dose exogenous CORT significantly improved helpless behaviors, possibly by modulating the central noradrenergic system and regulation of BDNF expression in rats. Thus, AGN may be a useful agent for the treatment or alleviation of psychiatric disorders associated with depression and anxiety disorders.

Acupuncture stimulation improves scopolamine-induced cognitive impairment via activation of cholinergic system and regulation of BDNF and CREB expressions in rats.

BACKGROUND: Acupuncture is an alternative therapy that is widely used to treat various neurodegenerative diseases and effectively improve cognitive and memory impairment. The aim of this study was to examine whether acupuncture stimulation at the Baihui (GV20) acupoint improves memory defects caused by scopolamine (SCO) administration in rats. We also investigated the effects of acupuncture stimulation at GV20 on the cholinergic system as well as the expression of brain-derived neurotrophic factor (BDNF) and cAMP-response element-binding protein (CREB) in the hippocampus. METHODS: SCO (2 mg/kg, i.p.) was administered to male rats once daily for 14 days. Acupuncture stimulation at GV20 was performed for 5 min before SCO injection. After inducing cognitive impairment via SCO administration, we conducted a passive avoidance test (PAT) and the Morris water maze (MWM) test to assess behavior. RESULTS: Acupuncture stimulation at GV20 improved memory impairment as measured by the PAT and reduced the escape latency for finding the platform in the MWM test. Acupuncture stimulation at GV20 significantly alleviated memory-associated decreases in the levels of choline acetyltransferase (ChAT), BDNF and CREB proteins in the hippocampus. Additionally, acupuncture stimulation at GV20 significantly restored the expression of choline transporter 1 (CHT1), vesicular acetylcholine transporter (VAChT), BDNF and CREB mRNA in the hippocampus. These results demonstrate that acupuncture stimulation at GV20 exerts significant neuroprotective effects against SCO-induced neuronal impairment and memory dysfunction in rats. CONCLUSIONS: These findings suggest that acupuncture stimulation at GV20 might be useful in various neurodegenerative diseases to improve cognitive functioning via stimulating cholinergic enzyme activities and regulating BDNF and CREB expression in the brain.

Acupuncture Stimulation Attenuates Impaired Emotional-Like Behaviors and Activation of the Noradrenergic System during Protracted Abstinence following Chronic Morphine Exposure in Rats.

The purpose of this study was to evaluate whether acupuncture stimulation attenuates withdrawal-induced behaviors in the rats during protracted abstinence following chronic morphine exposure. To do this, male rats were first exposed to morphine gradually from 20 to 100 mg/kg for 5 days, and subsequently naloxone was injected once to extend despair-related withdrawal behaviors for 4 weeks. Acupuncture stimulation was performed once at the SP6 (Sanyinjiao) acupoint on rat's; hind leg for 5 min during protracted abstinence from morphine. The acupuncture stimulation significantly decreased despair-like behavior deficits in the forced swimming test and low sociability in the open-field test as well as increased open-arm exploration in the elevated plus maze test in the last week of 4-week withdrawal period. Also the acupuncture stimulation significantly suppressed the increase in the hypothalamic corticotropin-releasing factor (CRF) expression, the decrease in the tyrosine hydroxylase expression in the locus coeruleus, and the decrease in the hippocampal brain-derived neurotrophic factor mRNA expression, induced by repeated injection of morphine. Taken together, these findings demonstrate that the acupuncture stimulation of SP6 significantly reduces withdrawal-induced behaviors, induced by repeated administration of morphine in rats, possibly through the modulation of hypothalamic CRF and the central noradrenergic system.

Baicalin improves chronic corticosterone-induced learning and memory deficits via the enhancement of impaired hippocampal brain-derived neurotrophic factor and cAMP response element-binding protein expression in the rat.

The purpose of this study was to examine whether baicalin (BAI) improves spatial cognitive impairments induced in rats following the repeated administration of the exogenous stress hormone corticosterone (CORT). The effect of BAI on the hippocampal expression of brain-derived neurotrophic factor (BDNF) and cAMP response element-binding protein (CREB) was also investigated. For 21 days, male rats received daily doses of BAI (20, 50, and 100 mg/kg, i.p.) 1 h prior to a CORT (40 mg/kg) injection. The daily administration of BAI improved memory impairment as measured by the passive avoidance test and reduced the escape latency for finding the platform in the Morris water maze test. Additionally, as assessed by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis, the administration of BAI also significantly alleviated memory-associated decreases in the expression levels of BDNF and CREB proteins and mRNAs in the hippocampus. These results demonstrate that the administration of BAI prior to high-dose exogenous CORT results in significant neuroprotective activity against neuronal impairment and memory dysfunction in rats. Thus, these findings suggest that BAI might be useful as a therapeutic agent in various neurodegenerative diseases for the improvement of cognitive function. This likely occurs through the regulation of BDNF and CREB expression.

Phosphatidylserine inhibits inflammatory responses in interleukin-1ß-stimulated fibroblast-like synoviocytes and alleviates carrageenan-induced arthritis in rat.

Recently, phosphatidylserine (PS) has received attention for its anti-inflammatory effect; however, the molecular mechanisms of its action have not been fully understood. Thus, we hypothesized that PS might have antiarthritic and anti-inflammatory effects. To test this hypothesis, the in vitro anti-inflammatory effect of soybean-derived PS was tested on interleukin (IL)-1ß-stimulated fibroblast-like synoviocytes from rheumatoid arthritis patients (RA-FLS) by measuring the levels of IL-6, IL-8, prostaglandin E(2), and vascular endothelial growth factor by enzyme-linked immunosorbent assay. The analgesic and antiarthritic activities of PS were investigated in rat models of carrageenan-induced acute paw pain and arthritis. The former was evaluated with a paw pressure test; the latter, by measuring paw volume and weight distribution ratio. In addition, the participation of mitogen-activated protein kinase signaling in the anti-inflammatory and antiarthritic effects of PS was investigated in RA-FLS. Phosphatidylserine inhibited the production of inflammatory mediators IL-6; IL-8; vascular endothelial growth factor; and, in particular, prostaglandin E(2) in IL-1ß-stimulated RA-FLS. These effects were associated with abrogation of inhibitor of nuclear factor-κBα phosphorylation and suppression of p38 and c-jun amino terminal kinase but not extracellular signal-regulated kinase 1/2 phosphorylation. In rats, PS also showed a significant inhibitory effect on arthritic and nociceptive symptoms induced by carrageenan. These findings suggest that PS has anti-inflammatory and antiarthritic effects in vitro and in in vivo animal models; thus, PS should be further studied to determine its potential use as either a pharmaceutical or dietary supplement for alleviating arthritic symptoms.

Modulatory effects of acupuncture on murine depression-like behavior following chronic systemic inflammation.

Depression associated with inflammatory immune responses may be an important medical problem from the perspective of quality of life in old age because chronic inflammation is recognized to have a close connection with the aging process. Activated proinflammatory cytokines induce depression-like behavior by stimulating the expression of indoleamine-2,3-dioxygenase, an enzyme catalyzing the conversion of tryptophan to kynurenine, and by reducing brain synaptic activities of serotonin and dopamine. Experimental inoculation of Bacillus Calmette-Guérin vaccine (BCG) in the mouse gradually and continuously elicits chronic inflammation-associated depression-like behavior. Despite extensive use of acupuncture therapy for treating various psychosomatic disorders in the Oriental medicine, an experimental study showing antidepressant-like activity of acupuncture stimulation has not been performed in the inflammation-associated depression-like animal behavior yet. In the present study, the antidepressant-like activity of acupuncture and its mechanism of action were investigated in BCG-inoculated mice. We confirmed that acupuncture stimulation significantly reduced depression-like behavior and that it lowered the kynurenine/tryptophan ratio and raised the serum kynurenic acid/3-hydroxykynurenine ratio. Acupuncture also relieved the hippocampal dopamine level that was lowered by BCG inoculation. Taken together, these findings may indicate that acupuncture has antidepressant-like effects on murine chronic inflammation-associated depression-like behavior due to its modulatory effects on tryptophan-kynurenine metabolism and dopamine metabolism in the brain.

Acupuncture stimulation alleviates corticosterone-induced impairments of spatial memory and cholinergic neurons in rats.

The purpose of this study was to examine whether acupuncture improves spatial cognitive impairment induced by repeated corticosterone (CORT) administration in rats. The effect of acupuncture on the acetylcholinergic system was also investigated in the hippocampus. Male rats were subcutaneously injected with CORT (5 mg/kg) once daily for 21 days. Acupuncture stimulation was performed at the HT7 (Sinmun) acupoint for 5 min before CORT injection. HT7 acupoint is located at the end of transverse crease of ulnar wrist of forepaw. In CORT-treated rats, reduced spatial cognitive function was associated with significant increases in plasma CORT level (+36%) and hippocampal CORT level (+204%) compared with saline-treated rats. Acupuncture stimulation improved the escape latency for finding the platform in the Morris water maze. Consistently, the acupuncture significantly alleviated memory-associated decreases in cholinergic immunoreactivity and mRNA expression of BDNF and CREB in the hippocampus. These findings demonstrate that stimulation of HT7 acupoint produced significant neuroprotective activity against the neuronal impairment and memory dysfunction.

Krill phosphatidylserine improves learning and memory in Morris water maze in aged rats.

The ameliorating effect of phosphatidylserine (PS) isolated from krill (KR-PS) on the learning and memory deficits associated with normal aging in rats was investigated, as compared with soybean PS (SOY-PS). Rats were orally administered with KR-PS (20, 50 mg kg-1) and SOY-PS (50 mg kg-1) daily, for 7 days, 30 min before behavioral assessment using the Morris water maze (MWM). Changes in the cholinergic system were examined by measuring choline acetyltransferase (ChAT) and acetylcholinesterase (AchE) immunoreactivity in the hippocampus. The daily administration of KR-PS produced a significant improvement in the escape latency for finding the platform in the MWM, as compared with SOY-PS. Consistent with the behavioral results, KR-PS treatments significantly alleviated age-associated losses of cholinergic immunoreactivity, and muscarinic acetylcholine receptor type 1 (mAChR-M1) and choline transporter (CHT) mRNA expression in the hippocampus. These findings demonstrate that KR-PS showed significant neuroprotective activity against the neuronal and cognitive impairments that occur with normal aging in rats; comparable results were obtained with SOY-PS. These data indicate that oral administration of PS derived from marine life could substitute for bovine cerebral cortex PS (BC-PS) as therapy for the improvement of diminished memory function in elderly people.