Naoxinqing tablet protects against cerebral ischemic/reperfusion injury by regulating ampkα/NAMPT/SIRT1/PGC-1α pathway.

AIM OF THE STUDY: Naoxinqing (NXQ) tablets are derived from persimmon leaves and are widely used in China for promoting blood circulation and removing blood stasis in China. We aimed to explore whether NXQ has the therapeutic effect on ischemic stroke and explored its possible mechanism. MATERIALS AND METHODS: The cerebral artery occlusion/reperfusion (MCAO/R) surgery was used to establish the cerebral ischemic/reperfusion rat model. NXQ (60 mg/kg and 120 mg/kg) were administered orally. The TTC staining, whole brain water content, histopathology staining, immunofluorescent staining, enzyme-linked immunosorbent assay (ELISA) and Western blot analyses were performed to determine the therapeutical effect of NXQ on MCAO/R rats. RESULTS: The study demonstrated that NXQ reduced the cerebral infarction volumes and neurologic deficits in MCAO/R rats. The neuroprotective effects of NXQ were accompanied by inhibited oxidative stress and inflammation. The nerve regeneration effects of NXQ were related to regulating the AMPKα/NAMPT/SIRT1/PGC-1α pathway. CONCLUSION: In summary, our results revealed that NXQ had a significant protective effect on cerebral ischemia-reperfusion injury in rats. This study broadens the therapeutic scope of NXQ tablets and provides new neuroprotective mechanisms of NXQ as an anti-stroke therapeutic agent.

Protective effect of Xinmai'an tablets via mediation of the AMPK/SIRT1/PGC-1α signaling pathway on myocardial ischemia-reperfusion injury in rats.

BACKGROUND: Xinmai'an tablets are a compound Chinese medicine comprising six traditional Chinese medicines that have been clinically applied to treat cardiovascular diseases such as premature ventricular contractions for many years. However, pharmacological effects and underlying mechanisms of Xinmai'an tablet in protecting against myocardial ischemia-reperfusion injury (MIRI) were barely ever studied. PURPOSE: To investigate the cardioprotective properties of Xinmai'an tablet against MIRI and the underlying molecular mechanism in rats. METHODS: We initially established the UHPLC-QTRAP-MS/MS analysis method to ensure the controllable quality of Xinmai'an tablet. We further identified the cardioprotective effects of Xinmai'an tablet against MIRI using TTC staining, hematoxylin and eosin, echocardiography, the transmission electron microscope analysis, biochemical analysis, and ELISA. We then investigated whether the safeguarding effect of Xinmai'an tablet on MIRI model rats was related to AMPK/SIRT1/PGC-1α pathway via western blotting. RESULTS: Xinmai'an tablet decreased myocardial infarct size; ameliorated cardiac function; alleviated myocardial and mitochondrial damage; and suppressed oxidative stress injury, vascular endothelial damage, and apoptosis response in MIRI model rats. Mechanistically, our results showed that Xinmai'an tablet can dramatically activate the AMPK/SIRT1/PGC-1αpathway and subsequently diminish mitochondrial oxidative stress damage. This was evidenced by increased ATP, Na+-K+-ATPase, and Ca2+-Mg2+-ATPase levels, upregulation of GLUT4, p-AMPK, SIRT1, and PGC-1α protein levels; and reduced GLUT1 protein level. CONCLUSION: To the knowledge of the author of this article, this study is the first report of Xinmai'an tablet attenuating MIRI, potentially associated with the activation of the AMPK/SIRT1/PGC-1α pathway and subsequent reduction of mitochondrial oxidative stress damage. These findings reveal a novel pharmacological effect and mechanism of action of Xinmai'an tablet and highlight a promising therapeutic drug for ischemic cardiovascular diseases.

MS/MS molecular networking-guided in-depth profiling of triterpenoid saponins from the fruit of Eleutherococcus senticosus and their neuroprotectivity evaluation.

INTRODUCTION: Eleutherococcus senticosus fruit (ESF) is a natural health supplement resource that has been extensively applied as a tonic for the nervous system. The structures and neural bioactivities of triterpenoid saponins (TS), which are the major constituents of ESF, have not been comprehensively analyzed thus far. OBJECTIVE: We conducted a complete in-depth MS/MS molecular networking (MN)-based targeted analysis of TS from the crude extract of ESF and investigated its neuroprotective value. METHODS: An MS/MS MN-guided strategy was used to rapidly present a series of precursor ions (PIs) of TS in a compound cluster as TS-targeted information used in the discovery and characterization of TS. In addition, a prepared TS-rich fraction of ESF was assayed for its restraining effects on ß-amyloid-induced inhibition of neurite outgrowth. RESULTS: A total of 87 TS were discovered using a PI tracking strategy, 28 of which were characterized as potentially undescribed structures according to their high-resolution MS values. Furthermore, the TS-rich fraction can significantly reduce ß-amyloid-induced damage to neural networks by promoting the outgrowth of neurites and axons. CONCLUSION: Our findings reveal the richness of TS in ESF and will accelerate their application in the treatment of neurodegenerative diseases.

Identification and localization of morphological feature-specific metabolites in Reynoutria multiflora roots.

Reynoutria multiflora roots are a classical herbal medicine with unique nourishing therapeutic effects. Anomalous vascular bundle (AVB) forming "cloudy brocade patterns" is a typical morphological feature of R. multiflora roots and has been empirically linked to its quality classification. However, scientific evidence, especially for AVB-specific specialised metabolites, has not been comprehensively revealed thus far. Herein, desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) analysis was applied to carry out an in situ analysis of specialised metabolites distributed specifically at the AVB and cork of R. multiflora roots. To enlarge the scope of compounds by DESI detection, various solvent systems including acetone, acetonitrile, methanol, and water were used to assist in the discoveries of 40 specialised metabolites with determined localization. A series of bioactive constituents including stilbenes, flavonoids, anthraquinones, alkaloids, and naphthalenes were found specifically around the brocade patterns. Notably, phospholipids were detected from R. multiflora roots by in situ analysis for the first time and were found mainly in the phloem of AVB (PAB). This is the first study to use gradient solvent systems in DESI-MSI analysis to locate the specialised metabolites distribution. The discovery of feature-specific compounds will bridge the empirical identification to precision quality control of R. multiflora roots.

Persimmon leaf extract alleviates chronic social defeat stress-induced depressive-like behaviors by preventing dendritic spine loss via inhibition of serotonin reuptake in mice.

BACKGROUND: Fresh or dried Persimmon leaves (Diospyros kaki Thunb.) exhibit preventive effects on cardiovascular and cerebrovascular diseases. However, their antidepressant effects and underlying mechanisms are unclear. Thus, we investigated mechanisms responsible for Persimmon leaf extract (PLE) activity on chronic social defeat stress (CSDS)-induced depressive-like behaviors in mice. METHODS: CSDS was used as a mouse model of depression. We performed the sucrose preference test (SPT), forced swim test (FST), and tail suspension test (TST) to identify depressive-like behavior. Spine density and dendritic morphology were assessed using Golgi staining. Neurochemicals were quantified by microdialysis, doublecortin by immunofluorescence, and cAMP using an ELISA kit. Finally, the levels of cortical proteins of phosphorylated cAMP-response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), postsynaptic density synapsin-1 and protein 95 (PSD95) were quantified by western blot. 16S rRNA gene sequencing was used to detect fecal microbiota. RESULTS: Treatment of CSDS-subjected mice with PLE (30.0-60.0 mg/kg, i.g.) enhanced sucrose preference, decreased immobility times in the TST and FST but did not affect locomotor activity. Furthermore, persistent social defeat stress decreased dendritic spine density and dendritic length in the brain, as well as decreased PSD95 and synapsin-1 expression. PLE, interestingly, inhibited dendritic spine loss and increased synaptic protein levels. PLE also increased brain levels of 5-HT, cAMP, phosphorylated (p)-CREB, BDNF, PSD95, and synapsin-1 in mice subjected to CSDS. Furthermore, PLE increased their doublecortin-positive cell count in the hippocampal dentate gyrus. CSDS mice represented a distinct fecal microbiota cluster which differed compared with normal C57BL/6J mice, and the phenotype was rescued by PLE. CONCLUSIONS: PLE alleviated CSDS-induced depressive behaviors and spinal damage by suppressing serotonin reuptake and activating the cAMP/CREB/BDNF signaling pathway. Simultaneously, PLE influenced the composition of the fecal microbiota in CSDS-subjected mice.

Rabdosia serra alleviates dextran sulfate sodium salt-induced colitis in mice through anti-inflammation, regulating Th17/Treg balance, maintaining intestinal barrier integrity, and modulating gut microbiota.

Rabdosia serra (R. serra), an important component of Chinese herbal tea, has traditionally been used to treat hepatitis, jaundice, cholecystitis, and colitis. However, the chemical composition of R. serra and its effect against colitis remain unclear. In this study, the chemical composition of the water extract of R. serra was analyzed using ultra performance liquid chromatography coupled with a hybrid linear ion trap quadrupole-orbitrap mass spectrometer (UPLC-LTQ-Orbitrap-MS). A total of 46 compounds, comprising ent-kaurane diterpenoids, flavonoids, phenolic acids, and steroids, were identified in the water extract of R. serra, and the extract could significantly alleviate dextran sulfate sodium salt-induced colitis by improving colon length, upregulating anti-inflammatory factors, downregulating proinflammatory factors, and restoring the balance of T helper 17/T regulatory cells. R. serra also preserved intestinal barrier function by increasing the level of tight junction proteins (zonula occludens 1 and occludin) in mouse colonic tissue. In addition, R. serra modulated the gut microbiota composition by increasing bacterial richness and diversity, increasing the abundance of beneficial bacteria (Muribaculaceae, Bacteroides, Lactobacillus, and Prevotellaceae_UCG-001), and decreasing the abundance of pathogenic bacteria (Turicibacter, Eubacterium_fissicatena_group, and Eubacterium_xylanophilum_group). Gut microbiota depletion by antibiotics further confirmed that R. serra alleviated colitis in a microbiota-dependent manner. Overall, our findings provide chemical and biological evidence for the potential application of R. serra in the management of colitis.

Anti-hyperlipidemic effects of the compound Danshen tablet: roles of antioxidation, anti-inflammation, anticoagulation, and anti-apoptosis.

BACKGROUND: Hyperlipidemia could cause some serious harm to human health diseases, such as atherosclerosis, coronary heart disease. This study sought to investigate the effects of the compound Danshen tablet (CDT) on hyperlipidemia induced by a high-fat diet in ApoE-/- mice and related antioxidation, anti-inflammation, anticoagulation, and anti-apoptosis mechanisms. METHODS: The control group (Group 1) comprised 15 male C57BL/6N mice, and the other 5 groups (Groups 2-6) comprised 75 male ApoE-/- mice. These 75 mice were randomly divided into 1 of the following 5 groups: Group 2, a model group; Groups 3-5, the CDT groups, each of which was administered 375, 750, or 1,500 mg/kg of CDT; and Group 6, an atorvastatin group, which was administered 5.2 mg/kg of atorvastatin. All the mice were fed a high-fat diet for 16 weeks and intragastrically administered with CDT or atorvastatin once a day according to their body weight. After 16 weeks, serum was collected, the aorta was isolated, and blood lipid levels were detected. An enzyme-linked immunosorbent assay was used to detect the serum levels of 4-hydroxynonenal (4-HNE), 8-hydroxy-2'-deoxyguanosine (8-OHdG), intercellular adhesion molecule 1 (ICAM-1), monocyte chemoattractant protein 1 (MCP-1), thromboxane B2 (TXB2), tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1). The thickness of the aortic wall was measured by ultrasonography. Atherosclerotic plaque and endothelial cell apoptosis in the aortic root were evaluated using oil red O staining and terminal dUTP nick-end labeling (TUNEL) assays, respectively. RESULTS: A comparison of mice in the CDT group and mice in the model group showed that CDT significantly inhibited mice's weight gain. CDT reduced the levels of the inflammatory factor ICAM-1 and the oxidative damage molecule 4-HNE. In the coagulation system, CDT significantly increased tPA levels and reduced TXB2 and PAI-1 levels. Ultrasonography showed that CDT increased the thickness of the aortic wall. The oil red O staining results revealed that CDT significantly ameliorated lipid accumulation in the aortic valve. TUNEL assays indicated that CDT reduced the number of TUNEL-positive cells in the aortic valve. CONCLUSIONS: CDT has a certain protective effect on hyperlipidemia. The mechanism of CDT may be related to antioxidation, anti-inflammation, anticoagulation, and anti-apoptosis.

Danhong Huayu Koufuye prevents venous thrombosis through antiinflammation via Sirtuin 1/NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Danhong Huayu Koufuye (DHK), a compound traditional Chinese medicine, is composed of Salvia miltiorrhiza radix (Salvia miltiorrhiza Bge.), Angelicae Sinensis radix (Angelicae Sinensis (Oliv.) Diels.), Chuanxiong rhizoma (Ligusticum chuanxiong Hort.), Persicae semen (Prunus persica (L.) Batsch), Carthami flos (Carthamus tinctorius L.), Bupleuri radix (Bupleurum chinense DC.) and Aurantii fructus (Citrus aurantium L.). DHK prevents deep vein thrombosis (DVT) through antiinflammation. However, the antiinflammatory mechanism of DHK is still unknown. OBJECTIVE: The aim of this study was to evaluate whether DHK prevented venous thrombosis through antiinflammation via Sirtuin 1 (SIRT1)/NF-κB signaling pathway. METHODS: Inferior vena cava (IVC) stenosis-induced DVT rat model was established. Rats were administered with DHK (1.6, 3.2 or 6.4 mL/kg/d, p.o.), heparin (200 U/kg/d, i.v.), clopidogrel (25 mg/kg/d, p.o.), resveratrol (50 mg/kg/d, p.o.) or vehicle (p.o.) once daily for two days. Blood coagulation, blood fibrinolysis, blood viscosity, blood cell counts and platelet activity were evaluated. Serum levels of inflammatory cytokines were analyzed by enzyme-linked immunosorbent assay. Pathological changes were observed by hematoxylin-eosin (HE) staining. Protein expressions in thrombosed IVCs were evaluated by Western blot and/or immunofluorescence analyses. SIRT1 mRNA expression was analyzed by real-time quantitative polymerase chain reaction. Besides, SIRT1-specific inhibitor EX527 was pretreated to confirm the role of SIRT1/NF-κB signaling pathway in the antithrombotic effect of DHK. RESULTS: DHK remarkably prevented DVT. DHK had no effects on blood coagulation, blood fibrinolysis, blood viscosity, blood cell counts or platelet activity. But DHK significantly up-regulated protein and mRNA expressions of SIRT1, and reduced leukocytes infiltration into thrombus and vein wall, serum levels of inflammatory cytokines, and protein expressions of acetylated p65 (Ace-p65), phosphorylated p65 (p-p65) and tissue factor (TF). Moreover, the antithrombotic effect of DHK was significantly abolished by EX527. CONCLUSION: DHK may prevent DVT by inhibiting inflammation via SIRT1/NF-κB signaling pathway.

Novel Phosphodiesterase 4 Inhibitor FCPR03 Alleviates Lipopolysaccharide-Induced Neuroinflammation by Regulation of the cAMP/PKA/CREB Signaling Pathway and NF-κB Inhibition.

Overactivation of microglia contributes to the induction of neuroinflammation, which is highly involved in the pathology of many neurodegenerative diseases. Phosphodiesterase 4 (PDE4) represents a promising therapeutic target for anti-inflammation; however, the dose-limiting side effects, such as nausea and emesis, have impeded their clinic application. FCPR03, a novel selective PDE4 inhibitor synthesized in our laboratory, shows little or no emetic potency; however, the anti-inflammatory activities of FCPR03 in vitro and in vivo and the molecular mechanisms are still not clearly understood. This study was undertaken to delineate the anti-inflammatory effects of FCPR03 both in vitro and in vivo and explore whether these effects are regulated by PDE4-mediated signaling pathway. BV-2 microglial cells stimulated by lipopolysaccharide (LPS) and mice injected i.p. with LPS were established as in vitro and in vivo models of inflammation. Our results showed that FCPR03 dose dependently suppressed the production of tumor necrosis factor α, interleukin-1ß, and iinterleukin-6 in BV-2 microglial cells treated with LPS. The role of FCPR03 in the production of proinflammatory factors was reversed by pretreatment with protein kinase A (PKA) inhibitor H89. In addition, FCPR03 reduced the levels of proinflammatory factors in the hippocampus and cortex of mice injected with LPS. Our results further demonstrated that FCPR03 effectively increased the production of cAMP, promoted cAMP response element binding protein (CREB) phosphorylation, and inhibited nuclear factor κB (NF-κB) activation both in vitro and in vivo. Our findings suggest that FCPR03 inhibits the neuroinflammatory response through the activation of cAMP/PKA/CREB signaling pathway and NF-κB inhibition.

FFPM, a PDE4 inhibitor, reverses learning and memory deficits in APP/PS1 transgenic mice via cAMP/PKA/CREB signaling and anti-inflammatory effects.

Thus far, phosphodiesterase-4 (PDE4) inhibitors have not been approved for application in Alzheimer's disease (AD) in a clinical setting due to severe side effects, such as nausea and vomiting. In this study, we investigated the effect of FFPM, a novel PDE4 inhibitor, on learning and memory abilities, as well as the underlying mechanism in the APP/PS1 mouse model of AD. Pharmacokinetic studies have revealed that FFPM efficiently permeates into the brain, and reached peak values in plasma 2 h after orally dosing. A 3-week treatment with FFPM, at doses of 0.25 mg/kg and 0.5 mg/kg, significantly improved the learning and memory abilities of APP/PS1 transgenic mice in the Morris water maze and the Step-down passive avoidance task. Interestingly, we found that while rolipram (0.5 mg/kg) reduced the duration of the α2 adrenergic receptor-mediated anesthesia induced by xylazine/ketamine, FFPM (0.5 mg/kg) or the vehicle did not have an evident effect. FFPM increased the cAMP, PKA and CREB phosphorylation and BDNF levels, and reduced the NF-κB p65, iNOS, TNF-α and IL-1ß levels in the hippocampi of APP/PS1 trangenic mice, as observed by ELISA and Western blot analysis. Taken together, our data demonstrated that the reversal effect of FFPM on cognitive deficits in APP/PS1 transgenic mice might be related to stimulation of the cAMP/PKA/CREB/BDNF pathway and anti-inflammatory effects. Moreover, FFPM appears to have potential as an effective PDE4 inhibitor in AD treatment with little emetic potential.

Inhibition of phosphodiesterase-4 reverses the cognitive dysfunction and oxidative stress induced by Aß25-35 in rats.

Phosphodiesterase-4 (PDE4) inhibitors prevent the breakdown of the second messenger cAMP and have been demonstrated to improve learning in several animal models of cognition. In this study, we explored the antioxidative effects of rolipram in Alzheimer's disease (AD) by using bilateral Aß25-35 injection into the hippocampus of rats, which were used as an AD model. Rats received 3 intraperitoneal (i.p.) doses of rolipram (0.1, 0.5 and 1.25 mg/kg) daily after the injection of Aß25-35 for 25 days. Chronic administration of rolipram prevented the memory impairments induced by Aß25-35, as assessed using the passive avoidance test and the Morris water maze test. Furthermore, rolipram significantly reduced the oxidative stress induced by Aß25-35, as evidenced by the decrease in the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and restored the reduced GSH levels and superoxide dismutase (SOD) activity. Moreover, western blotting and real-time reverse transcription polymerase chain reaction (RT-PCR) analysis showed that rolipram remarkably upregulated thioredoxin (Trx) and inhibited the inducible nitric oxide synthase/nitric oxide (iNOS/NO) pathway in the hippocampus. These results demonstrated that rolipram improved the learning and memory abilities in an Aß25-35-induced AD rat model. The mechanism underlying these effects may be due to the noticeable antioxidative effects of rolipram.

cAMP/PKA/CREB/GLT1 signaling involved in the antidepressant-like effects of phosphodiesterase 4D inhibitor (GEBR-7b) in rats.

OBJECTIVES: GEBR-7b, a potential phosphodiesterase 4D inhibitor, has been shown to have memory-enhancing effects in rodents. However, it is still unknown whether GEBR-7b also has the antidepressant-like effects in rats. Herein, we examined the potential of GEBR-7b to attenuate depression-like behaviors in the rat model of depression induced by chronic unpredictable stress (CUS). Next, we also investigated the alterations of cyclic adenosine monophosphate (cAMP), protein kinase A (PKA) catalytic subunit (PKAca), cAMP response element-binding (CREB), and glutamate transporter 1 (GLT1) levels produced by GEBR-7b in the rats model of depression. METHODS: Effects of GEBR-7b on CUS (35 days)-induced depression-like behaviors were examined by measuring immobility time in the forced swimming test (FST). Hippocampal cAMP levels were examined by enzyme-linked immunosorbent assay, whereas PKAca, phosphorylation of CREB (pCREB), CREB, and GLT1 in the hippocampus of rats were subjected to Western blot analysis. RESULTS: CUS exposure caused a depression-like behavior evidenced by the increased immobility time in FST. Depression-like behavior induced by CUS was accompanied by a significant increased GLT, decreased cAMP, PKAca, pCREB activities in hippocampus. However, repeated GEBR-7b administration significantly reversed CUS-induced depression-like behavior and changes of cAMP/PKA/CREB/GLT1 signaling. No alteration was observed in locomotor activity in open field test. CONCLUSION: These findings indicate that GEBR-7b reversed the depression-like behaviors induced by CUS in rats, which is at least in part mediated by modulating cAMP, PKAca, pCREB, and GLT1 levels in the hippocampus of rats, supporting its neuroprotective potential against behavioral and biochemical dysfunctions induced by CUS.

Determination of a novel phosphodiesterase-4 inhibitor chlorbipram in mouse plasma and brain by UFLC-MS/MS: Application in pharmacokinetic studies after intravenous administration.

In this study, we evaluated a simple and sensitive method for determination of a novel phosphodiesterase-4 (PDE4) inhibitor, chlorbipram, in mouse plasma and brain using ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS). Separation was achieved using an Acquity UPLC BEH C18 column (50mm×2.1mm, particle size 1.7µm) with a gradient mobile phase consisting of water and methanol at a flow rate of 0.25ml/min. Detection was performed in the multiple reaction monitoring (MRM) mode using electrospray ionization (ESI) in the positive ion mode. The liquid-liquid extraction method with ethyl acetate was used for both pretreatment of plasma and brain homogenates. The calibration curves of chlorbipram showed good linearity over the concentration range of 0.5-200ng/ml (R(2)>0.994) for mouse plasma and over the range of 0.25-100ng/ml (R(2)>0.994) for mouse brain homogenate. The extraction recovery was in the range of 78.3-84.8% for chlorbipram and the internal standard (IS) ZXI14 in two different biological matrices. The intra- and inter-day precision values were less than 13.0% and the accuracy ranged from 97.8% to 106.0% for quality control samples. No noteworthy matrix effects and instability were observed for chlorbipram. This validated method was successfully applied to a pharmacokinetic study of chlorbipram in mice after intravenous administration. The results show that this novel drug crosses the blood-brain barrier and provides the basis for further studies on chlorbipram.

Cognitive improvement of compound danshen in an Aß25-35 peptide-induced rat model of Alzheimer's disease.

BACKGROUND: Senile dementia mainly includes Alzheimer' s disease (AD) and vascular dementia (VD). AD is a progressive and irreversible neurodegenerative disorder that is accompanied with a great deal of social burden. The aim of this study was to investigate the effect of Compound Danshen (CDS) on learning and memory of alzheimer's disease (AD) rat model, as well as to explore the possible connection between CDS and the associated molecules of amyloid beta (Aß). METHODS: Rats were injected with Aß25-35 peptide intracerebroventricularly and CDS were subsequently administered once daily for 23 days. Rats' behavior was monitored using Morris water maze and passive avoidance. Real time PCR and Western blotting were used in determining amyloid precursor protein (APP), ß-site APP cleaved enzyme-1(BACE1), Presenilin-1 (PS1), Insulin-degrading enzyme (IDE) and neprilysin (NEP) in hippocampus. RESULTS: The AD model group presented with spatial learning and memory impairments. CDS and donepezil administration significantly ameliorated the Aß25-35 peptide-induced memory impairment in both Morris water maze (P < 0.05) and passive avoidance task (P < 0.01) compared to the AD model group. Real time PCR results suggested that CDS significantly decreased APP mRNA, PS1 mRNA and increased IDE and NEP mRNA levels. Western blotting analyses showed that CDS decreased the protein expression of APP and PS1 and increased IDE expression. CONCLUSION: CDS improved spatial learning and memory by down-regulating APP, PS1 levels and up-regulating IDE. In future, CDS may have significant therapeutic potential in the treatment of AD patients.

C-Reactive Protein Induces Tau Hyperphosphorylation via GSK3ß Signaling Pathway in SH-SY5Y Cells.

Amyloid plaques and neurofibrillary tangles are the key pathological features of Alzheimer's disease (AD). Studies have shown that C-reactive protein (CRP) increases during inflammatory reactions and, therefore, has been associated with AD. However, there is no published report relating the impact of CRP to the regulation of tau phosphorylation. In the present study, we investigated the effects of CRP on the phosphorylation of tau protein in SH-SY5Y cells. Treatment of cells with CRP (5, 10, 20 µg/ml) resulted in neurotoxicity and apoptosis, as was observed by MTT assay and Hoechst staining, respectively. Western blot analysis showed that CRP, in a time- and concentration-dependent manner, induced the phosphorylation of tau at Ser202 and ser396 in SH-SY5Y cells. Phosphorylation of Akt (Ser473) and GSK3ß (Ser9) were decreased by CRP treatment, whereas phosphorylation of ERK and p38 were not affected. Pharmacological inhibition of GSK3ß reversed the effects induced by CRP, viz., cytotoxicity, apoptosis, and tau phosphorylation. Herein, we present a novel mechanism of cell death following CRP insult, which activates tau hyperphosphorylation by regulating GSK3ß activity. CRP could potentially be used as an important pathological factor for the therapeutic intervention of AD.

Neuroprotection, learning and memory improvement of a standardized extract from Renshen Shouwu against neuronal injury and vascular dementia in rats with brain ischemia.

ETHNOPHARMACOLOGICAL RELEVANCE: The Renshen Shouwu capsule (RSSW) is a patented Traditional Chinese Medicine (TCM), that has been proven to improve memory and is widely used in China to apoplexy syndrome and memory deficits. To investigate the neuroprotective and therapeutic effect of the Renshen Shouwu standardized extract (RSSW) on ischemic brain neuronal injury and impairment of learning and memory related to Vascular Dementia (VD) induced by a focal and global cerebral ischemia-reperfusion injury in rats. MATERIAL AND METHODS: Using in vivo rat models of both focal ischemia/reperfusion (I/R) injuries induced by a middle cerebral artery occlusion (MCAO), and VD with transient global brain I/R neuronal injuries induced by a four-vessel occlusion (4-VO) in Sprague-Dawley (SD) rats, RSSW (50,100, and 200 mg kg(-1) body weights) and Egb761® (80 mg kg(-1)) were administered orally for 20 days (preventively 6 days+therapeutically 14 days) in 4-VO rats, and for 7 days (3 days preventively+4 days therapeutically) in MCAO rats. Learning and memory behavioral performance was assayed using a Morris water maze test including a place navigation trial and a spatial probe trial. Brain histochemical morphology and hippocampal neuron survival was quantified using microscope assay of a puffin brain/hippocampus slice with cresyl violet staining. RESULTS: MCAO ischemia/reperfusion caused infarct damage in rat brain tissue. 4-VO ischemia/reperfusion caused a hippocampal neuronal lesion and learning and memory deficits in rats. Administration of RSSW (50, 100, and 200mg/kg) or EGb761 significantly reduced the size of the insulted brain hemisphere lesion and improved the neurological behavior of MCAO rats. In addition, RSSW markedly reduced an increase in the brain infarct volume from an I/R-induced MCAO and reduced the cerebral water content in a dose-dependent way. Administration of RSSW also increased the pyramidal neuronal density in the hippocampus of surviving rats after transient global brain ischemia and improved the learning and memory ability of rats with 4-VO induced vascular dementia in a dose-dependent manner. CONCLUSIONS: The in vivo results suggested that RSSW has significant neuroprotective effects against MCAO and 4-VO I/R injury and a therapeutic effect on cognitive disorders in VD rats. RSSW also improved the learning and memory ability of VD rats. These results convincingly demonstrated that RSSW may be useful to prevent and treat ischemia/reperfusion injury and vascular dementia disease.

Involvement of norepinephrine and serotonin system in antidepressant-like effects of hederagenin in the rat model of unpredictable chronic mild stress-induced depression.

CONTEXT: Previous studies from our laboratory indicated that both acute and subchronic administration of Fructus Akebiae (FAE) [the fruit of Akebiae quinata (Thunb.) Decne, (Lardizabalaceae)] produce antidepressant-like effects in animal depressive behavior tests. FAE contains approximately 70% of hederagenin (HG) as its main chemical component. OBJECTIVE: This study compared the antidepressant ability of FAE with that of HG in mice and further investigated the antidepressant-like effects and potential mechanisms of HG in rats subjected to unpredictable chronic mild stress (UCMS). MATERIALS AND METHODS: Mice received FAE (50 mg/kg) and HG (20 mg/kg) once a day via intragastric administration (i.g.) for 3 weeks. The anxiolytic and antidepressant activities of FAE and HG were compared using elevated plus maze (EPM) and behavioral despair tests including tail suspension test (TST) and forced swimming test (FST), respectively. Antidepressant effects of HG (5 mg/kg) were assessed using the UCMS depressive rat model. Moreover, the levels of monoamine neurotransmitters and relevant gene expression in UCMS rats' hippocampi were determined through high-performance liquid chromatography with electrochemical detection and real-time polymerase chain reaction techniques. RESULTS: The results of our preliminary screening test suggest that HG at 20 mg/kg, while not FAE at 50 mg/kg, significantly decreased the immobility in both TST and FST compared with the vehicle group when administered chronically; however, there were no significant differences observed between the HG and the FAE group. Chronic administration of HG failed to significantly reverse the altered crossing and rearing behavioral performance, time spent in the open arm and closed entries in the EPM, even if they showed an increased tendency, but HG significantly increased the percent of sucrose preference in the sucrose preference test (SPT) and decreased the immobility time in the FST. HG showed that significant increases of norepinephrine and serotonin levels and exhibited a tendency to increase the expression of 5-hydroxytryptamine (serotonin) 1A receptor mRNA, and to significantly decrease the expression of the mRNA for the serotonin transporter (5-HTT). However, there were no significant differences in the expression of the brain-derived neurotrophic factor. CONCLUSION: These findings confirm the antidepressant-like effects of HG in a behavioral despair test and UCMS rat model, which may be associated with monoamine neurotransmitters and 5-HTT mRNA expression.