Qifu-yin activates the Keap1/Nrf2/ARE signaling and ameliorates synaptic injury and oxidative stress in APP/PS1 mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The traditional medicinal formulation, Qifu-yin (QFY), has been widely prescribed for Alzheimer's disease (AD) treatment in China, yet the comprehensive mechanisms through which QFY mitigates AD pathology remain to be fully delineated. AIM OF THE STUDY: This study aimed to explore the therapeutic implications of QFY on the synaptic injury and oxidative stress in the hippocampus of APPswe/PS1dE9 (APP/PS1) mice, with a concerted effort to elucidate the molecular mechanisms related to synaptic preservation and memory improvement. MATERIALS AND METHODS: The components of QFY were identified by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The neuroprotective effects of QFY was evaluated using six-month-old male APP/PS1 mice. Subsequent to a 15 days of QFY regimen, spatial memory was assessed utilizing the Morris water maze (MWM) test. Amyloid-beta (Aß) aggregation was detected via immunostaining, while the quantification of Aß1-40 and Aß1-42 was achieved through enzyme-linked immunosorbent assay (ELISA). Transmission electron microscopy (TEM) was used to investigate the synaptic structure and mitochondrial morphology. Golgi staining was applied to examine dendritic spine density. Reactive oxygen species (ROS), 3-nitrotyrosine (3-NT) and 4-hydroxy-nonenal (4-HNE) assays were employed to assess oxidative stress. The expression profiles of Aß metabolism-associated enzymes and the Keap1/Nrf2/ARE signaling pathway were determined by Western blot. RESULTS: A total of 20 principal compounds in QFY were identified. QFY mitigated memory deficits of APP/PS1 mice, including reducing escape latency and search distance and increasing the time and distance spent in the target quadrant. In addition, QFY increased platform crossings of APP/PS1 mice in the probe trial of MWM tests. TEM analysis showed that QFY increased synapse number in the CA1 region of APP/PS1 mice. Further studies indicated that QFY elevated the expression levels of Post synaptic density protein 95 (PSD95) and synaptophysin, and mitigated the loss of dendritic spine density in the hippocampus of APP/PS1 mice. QFY has been shown to ameliorated the structural abnormalities of mitochondria, including mitochondrial dissolution and degradation, up-regulate ATP synthesis and membrane potential in the hippocampus of APP/PS1 mice. Moreover, QFY activated the Keap1/Nrf2/ARE signaling pathway in the hippocampus of APP/PS1 mice, which might contribute to the neuroprotective effects of QFY. CONCLUSION: QFY activates the Keap1/Nrf2/ARE signaling, and protects against synaptic and mitochondrial dysfunction in APP/PS1 mice, proposing a potential alternative therapeutic strategy for AD management.

Protective Effect of Compound Tongluo Decoction on Brain Vascular Endothelial Cells after Ischemia-Reperfusion by Inhibition of Ferroptosis Through Regulating Nrf2/ARE/SLC7A11 Signaling Pathway.

Cerebral infarction is one of the most common diseases for aged people. Compound Tongluo Decoction (CTLD), a classic traditional Chinese Medicine prescription, has been widely used in the treatment of ischemic cerebral infarction. Transient middle cerebral artery occlusion (tMCAO) rat model is established for the animal experiment and oxygen-glucose deprivation and reperfusion (OGD/R) human umbilical vein endothelial cells (HUVECs) model are established for the cell experiment. This also use Nrf2-/- rats to detect the role of nuclear factor erythroid 2-related factor 2 (Nrf2). Longa score, Evans blue staining, brain water content measurement, and histological observation are done. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and other ferroptosis-related components are detected respectively. In the vivo experiment, CTLD relieved ischemia-reperfusion (IR) injury symptoms and attenuated IR injury in brain tissues of tMCAO rats by relieving peroxidation injury in brain tissues and inhibiting ferroptosis in tMCAO rats. Moreover, CTLD reversed OGD/R-induced oxidative damage of endothelial cells via suppressing ferroptosis. After knocking out the Nrf2 gene, the protective effect of CTLD is sharply reduced. This study put forward that CTLD can inhibit ferroptosis in I/R-injured vascular endothelium by regulating Nrf2/ARE/SLC7A11 signaling to improve the relative symptoms of rats after cerebral I/R injury, thus providing a viable treatment option for cerebrovascular disease.

Compound Tongluo Decoction inhibits endoplasmic reticulum stress-induced ferroptosis and promoted angiogenesis by activating the Sonic Hedgehog pathway in cerebral infarction.

ETHNOPHARMACOLOGICAL RELEVANCE: Cerebral infarction is one of the most common types of cerebrovascular diseases that threaten people's health. Compound Tongluo Decoction (CTLD), a traditional Chinese medicine formula, has various pharmacological activities, including the alleviation of cerebral infarction symptoms. AIM OF THE STUDY: This study aims to explore the potential mechanism by which CTLD alleviates cerebral infarction. MATERIAL AND METHODS: Middle cerebral artery occlusion (MCAO) rat model and oxygen-glucose deprivation and reperfusion (OGD/R) cell model were established for research. The expression of proteins related to endoplasmic reticulum (ER) stress, ferroptosis, Sonic Hedgehog (SHH) pathway and angiogenesis was analyzed by Western blot analysis. The expression of CD31 was detected by immunofluorescence to investigate angiogenesis. In addition, the expression of GRP78 and XBP-1 in brain tissues was investigated by immunohistochemistry. With the application of Prussian blue staining, iron deposition in brain tissue was detected. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD) were detected using ELISA kits. The angiogenesis was analyzed by tube formation assay. RESULTS: The results presented in this research showed that CTLD and 4-phenyl butyric acid (4-PBA; the inhibitor of ER stress) could alleviate cerebral infarction. Mechanistically, CTLD and 4-PBA rescued ER stress and ferroptosis, but promoted SHH signaling in rats with cerebral infarction. In addition, cerebral infarction exhibited a high level of angiogenesis, which was aggravated by CTLD but suppressed by 4-PBA. Furthermore, CTLD inhibited ER stress and ferroptosis, but promoted SHH signaling and angiogenesis in OGD/R-induced PC12 cells, which was partly abolished by SANT-1, an antagonist of SHH signaling. CONCLUSION: In conclusion, this study revealed that CTLD might inhibit ferroptosis induced by endoplasmic reticulum stress and promote angiogenesis by activating the Sonic Hedgehog pathway in rats with cerebral infarction.

The proteomics analysis of the effects of Zhishi Rhubarb soup on ischaemic stroke.

BACKGROUND: Stroke has always been a major threat worldwide but is most severe in China, with 2.5 million new stroke cases each year and 7.5 million stroke survivors, placing a heavy burden on the social and national health care systems. Zhishi Rhubarb Soup (ZRS) is a traditional Chinese medicine (TCM) that has been used clinically for many years in China. To explore the potential mechanism of ZRS in the treatment of stroke, liquid chromatography with mass spectrometry (LC-MS) was performed. METHODS: In this study, a quantitative proteomic method with LC-MS was used to analyse the proteomic differences between MACO samples treated with ZRS and those without ZRS treatment. RESULTS: Liquid chromatography with mass spectrometry (LC-MS) analysis led to the identification of 35,006 peptides, with 5160.0 proteins identified and 4094.0 quantified. Significantly differentially expressed proteins were identified through data analysis, and the difference was found to be more than 1.2 times (P < 0.05). The Gene Ontology (GO) analysis provided a summary of the dysregulated protein expression in the biological process (BP), cell component (CC), and molecular function (MF) categories. Proteins related to brain repair, including BDNF, IL-10, IL-6, and TGF-ß, were found to change significantly, partially demonstrating the effectiveness of ZRS to attenuate tissue injury. CONCLUSION: In this study, LC-MS/MS was performed to assess the effects of ZRS on differentially expressed proteins in rats with cerebral infarction. These promising results could help to improve the understanding of the effects of drugs on stroke.

Cerebral arterial fenestration associated with stroke and other cerebrovascular diseases.

BACKGROUND: Cerebral arterial fenestration is a rare vascular malformation that has not been fully understood. Whether it is related to cerebrovascular diseases remains to be determined. In this study, we aimed to investigate the imaging characteristics of cerebral fenestrations, the clinical characteristics of fenestrations complicated with cerebrovascular diseases, and the correlation between fenestrations and cerebrovascular diseases. METHODS: We reviewed the magnetic resonance imaging and computed tomography (CT) imaging findings of patients with cerebrovascular fenestrations in the Third Affiliated Hospital of Soochow University from January 2016 to December 2020, mainly focused on the shape and location of fenestrations. According to the location of fenestrated arteries, patients were divided into the internal carotid arterial system (ICAS) group and the vertebrobasilar arterial system (VAS) group. For patients complicated with cerebrovascular diseases, detailed data about the demographics and clinical characteristics were recorded. Stroke patients with injured lesions located in the territories of fenestrated arteries were further screened out and analyzed. Moreover, the proportions of cerebrovascular diseases including stroke between the ICAS group and the VAS group were compared. RESULTS: A total of 280 cerebrovascular fenestrations were found in 274 patients (six patients had two fenestrations). The most frequently involved vessels were the anterior cerebral artery (123/280), the basilar artery (76/280) and the vertebral artery (35/280). As to the shape of fenestrations, slit-like fenestrations accounted for 63.2% (177/280), followed by convex-lens-like type 26.1% (73/280) and duplicated type 10.7% (30/280). A total of 70 patients were complicated with cerebrovascular diseases, including ischemic stroke 64.3% (45/70), hemorrhagic stroke 22.9% (16/70), aneurysm 10% (7/70), arteriovenous malformation 1.4% (1/70) and cavernous hemangioma 1.4% (1/70). There were no significant differences between the ICAS group and the VAS group in terms of the demographics and clinical characteristics. Furthermore, among the 61 patients complicated with stroke, 16 patients' stroke lesions were located in the territories of fenestrated arteries, including 12.5% (2/16) in the ICAS and 87.5% (14/16) in the VAS. In addition, compared with the ICAS group, the proportions of cerebrovascular diseases including stroke in patients with fenestrations were higher in the VAS group (P < 0.05). CONCLUSIONS: Cerebral arterial fenestrations are most commonly found in the anterior cerebral artery, the basilar artery and the vertebral artery. Vertebrobasilar fenestrations are more related to cerebrovascular diseases, especially stroke.

Neuroprotective Effects and Related Mechanisms of Echinacoside in MPTP-Induced PD Mice.

OBJECTIVE: To explore the neuroprotective effect and the related mechanisms of echinacoside (ECH) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) mice. METHODS: Parkinson's disease is induced in mice by MPTP and the neurobehaviors of mice in different groups are observed. Then, immunohistochemistry and Western blot analysis are adopted to measure the expression of tyrosine hydroxylase (TH) and α-synuclein in the substantia nigra (SN). The content of dopamine (DA) and other neurotransmitters in the brain is detected by high-performance liquid chromatography. The expression of nerve growth factors and inflammatory factors in SN in mice in each group is measured by quantitative polymerase chain reaction. Finally, the expression of oxidative stress-related parameters in each group is measured. RESULTS: Compared with the model group, the pole-climbing time among mice in the moderate and high-dose ECH groups is significantly reduced (P < 0.01). The rotarod staying time, as well as fore and hind-limb strides, shows a significant increase (P < 0.01), as does spontaneous activity (P < 0.01). Moreover, the expression levels of TH, DA, glial cell line-derived neurotrophic factor, and brain-derived neurotrophic factor in SN in mice show significant increases in these two groups (P < 0.01). The content of superoxide dismutase, catalase, and glutathione peroxidase indicates significant increases in the low, moderate, and high-dose ECH groups (P < 0.01), and the content of MDA was reduced (P < 0.01). In the high-dose ECH group, the expression of interleukin (IL) 6 and tumor necrosis factor-α is significantly reduced (P < 0.01), while the expression of IL-10 shows a marked increase (P < 0.01) alongside a decrease in the expression of α-synuclein (P < 0.01). CONCLUSION: Echinacoside improves neurobehavioral symptoms in PD mice and significantly increases the expression of TH and DA. The neuroprotective effect potentially correlates with anti-inflammation and anti-oxidation actions, promotes the expression of nerve growth factor, and reduces the accumulation of α-synuclein.

Mechanism of Autophagy Regulation in MPTP-Induced PD Mice via the mTOR Signaling Pathway by Echinacoside.

OBJECTIVE: The present study aimed to investigate the effect of echinacoside on autophagy-related indicators through the mTOR signaling pathway, especially the effect on the clearance of autophagy substrate P62 and α-synuclein, the core pathological products of Parkinson's disease (PD), to provide new strategies for the treatment of PD. METHODS: A mouse model of subacute PD was established by the intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). First, the neurobehavioral symptoms in mice of each group were evaluated, and the monoamine neurotransmitters in the striatum in each group were measured with a high-performance liquid phase. Immunofluorescence double staining was adopted to observe the expression of tyrosine hydroxylase (TH), α-synuclein, and LC3. The transmission electron microscope was used to observe the changes of ultrastructure in substantia nigra and the formation of autophagosomes. Then, the expressions of TH, α-synuclein, Beclin 1, LC3, P62, mTOR, and the up-stream protein AKT were detected by Western blot. RESULTS: When compared with the model group, the neurobehavioral function significantly improved in the echinacoside group (P < 0.01), together with increased expression of TH, DA, and DOPAC in the brain (P < 0.01). In the echinacoside group, while the expressions of Beclin 1 and LC3-II increased (P < 0.01), the expression levels of P62 and α-synuclein decreased significantly (P < 0.01). Echinacoside could up-regulate the expression level of the survival signal p-AKT/AKT and decrease the expression of mTOR. CONCLUSION: Echinacoside could increase autophagy by inhibiting the expression of mTOR, thereby promoting the clearance of α-synuclein and the degradation of the autophagy substrate P62 and exerting the neuroprotective effect.

Huatuo Zaizao pill ameliorates cognitive impairment of APP/PS1 transgenic mice by improving synaptic plasticity and reducing Aß deposition.

BACKGROUND: It is well known that Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory deficits and cognitive decline. Amyloid-ß (Aß) deposition and synaptic dysfunction play important roles in the pathophysiology of Alzheimer's disease (AD). The Huatuo Zaizao pill (HT) is a Traditional Chinese Medicine (TCM) that has been used clinically for many years in China, mainly for post-stroke rehabilitation and cognitive decline; however, the mechanism of cognitive function is not clear. In this study, we investigated the effect of HT on hippocampal synaptic function, Amyloid-ß (Aß) deposition in APP/PS1 AD transgenic mice. METHOD: Six-month-old APP/PS1 transgenic (Tg) mice were randomly divided into control, HT-treated, and memantine (MEM)-treated groups. Then, these groups were orally administered vehicle (for the control), HT (0.25 g/kg) and MEM (5 mg/kg) respectively for 4 weeks. The Morris water maze, Novel Object Recognition, and Open field tests were used to assess cognitive behavioral changes. We evaluated the effects of HT on neuronal excitability, membrane ion channel activity, and synaptic plasticity in acute hippocampal slices by combining electrophysiological extracellular tests. Synaptic morphology in the hippocampus was investigated by electron microscopy. Western blotting was used to assess synaptic-associated protein and Aß production and degrading levels. Immunofluorescence staining was used to determine the relative integrated density. RESULTS: HT can ameliorate hippocampus-dependent memory deficits and improve synaptic dysfunction by reversing LTP impairment in APP/PS1 transgenic mice. Moreover, HT reduces amyloid plaque deposition by regulating α-secretase and γ-secretase levels. CONCLUSION: HT can improve the learning and memory function of APP/PS1 transgenic mice by improving synaptic function and reducing amyloid plaque deposition.

HDAC3 negatively regulates spatial memory in a mouse model of Alzheimer's disease.

The accumulation and deposition of beta-amyloid (Aß) is a key neuropathological hallmark of Alzheimer's disease (AD). Histone deacetylases (HDACs) are promising therapeutic targets for the treatment of AD, while the specific HDAC isoforms associated with cognitive improvement are poorly understood. In this study, we investigate the role of HDAC3 in the pathogenesis of AD. Nuclear HDAC3 is significantly increased in the hippocampus of 6- and 9-month-old APPswe/PS1dE9 (APP/PS1) mice compared with that in age-matched wild-type C57BL/6 (B6) mice. Lentivirus -mediated inhibition or overexpression of HDAC3 was used in the hippocampus of APP/PS1 mice to investigate the role of HDAC3 in spatial memory, amyloid burden, dendritic spine density, glial activation and tau phosphorylation. Inhibition of HDAC3 in the hippocampus attenuates spatial memory deficits, as indicated in the Morris water maze test, and decreases amyloid plaque load and Aß levels in the brains of APP/PS1 mice. Dendritic spine density is increased, while microglial activation is alleviated after HDAC3 inhibition in the hippocampus of 9-month-old APP/PS1 mice. Furthermore, HDAC3 overexpression in the hippocampus increases Aß levels, activates microglia, and decreases dendritic spine density in 6-month-old APP/PS1 mice. In conclusion, our results indicate that HDAC3 negatively regulates spatial memory in APP/PS1 mice and HDAC3 inhibition might represent a potential therapy for the treatment of AD.

CART modulates beta-amyloid metabolism-associated enzymes and attenuates memory deficits in APP/PS1 mice.

INTRODUCTION: Cocaine- and amphetamine-regulated transcript (CART) peptide has been demonstrated to exert neuroprotective effects in stroke and some neurodegeneration diseases. In current study, we investigated the protective effects and underlying mechanisms of CART in APP/PS1 mice. METHODS: The protein levels of CART, soluble Aß1-40 and Aß1-42 were measured in the hippocampus of APP/PS1 mice by enzyme-linked immunosorbent assay. We determined the mRNA and protein levels of Aß metabolism-associated enzymes including neprilysin (NEP), insulin-degrading enzyme (IDE), receptor for advanced glycation end products (RAGE), and low-density lipoprotein receptor-related protein 1 (LRP-1) in the hippocampus of APP/PS1 mice using real-time PCR and western blotting. Spatial memory was measured in APP/PS1 mice using the Morris water maze. The phosphorylation of AKT, ERK, p38, and JNK was determined using western blotting. RESULTS: The levels of soluble Aß1-40 and Aß1-42 were significantly decreased in the hippocampus of APP/PS1 mice after CART treatment. CART modulated the levels of NEP, IDE, RAGE, and LRP-1. In addition, CART inhibited the MAPK pathways and activated the AKT pathway, whereas inhibition of the AKT pathway decreased the levels of IDE and LRP-1. Furthermore, CART attenuated spatial memory deficits in the APP/PS1 mice. CONCLUSION: CART decreases the levels of soluble Aß in the hippocampus of APP/PS1 mice by modulating the expression of Aß metabolism-associated enzymes, which may be associated with the MAPK and AKT pathways.

Panaxatriol saponins promotes angiogenesis and enhances cerebral perfusion after ischemic stroke in rats.

BACKGROUND: Panaxatriol saponins (PTS), an extract from the traditional Chinese herb Panax notoginseng, which has been used to treat ischemic stroke for many years in China. However, the mechanism underlying the effects of PTS remains unclear. This study aimed to determine whether PTS can protect against ischemic brain injury by promoting angiogenesis and to explore the possible mechanism by which it promotes angiogenesis. METHODS: Middle cerebral artery occlusion (MCAO) was induced in rats, and neurological deficit scores and brain infarct volumes were assessed. Micro-Positron emission tomography (PET) was adopted to assess cerebral perfusion, and real-time PCR and western blotting were used to evaluate vascular growth factor and Sonic hedgehog (Shh) pathway component levels. Immunofluorescence staining was used to determine capillary densities in ischemic penumbrae. RESULTS: We showed that PTS improved neurological function and reduced infarct volumes in MCAO rats. Micro-PET indicated that PTS can significantly increase 18F-fluorodeoxyglucose (18F-PDG) uptake by ischemic brain tissue and enhance cerebral perfusion after MCAO surgery. Moreover, PTS was able to increase capillary densities and enhance angiogenesis in ischemic boundary zones and up-regulate vascular endothelial growth factor (VEGF) and Angiopoietin-1 (Ang-1) expression by activating the Shh signaling pathway. CONCLUSION: These findings indicate that PTS exerts protective effects against cerebral ischemic injury by enhancing angiogenesis and improving microperfusion.

Malibatol A enhances alternative activation of microglia by inhibiting phosphorylation of Mammalian Ste20-like kinase1 in OGD-BV-2 cells.

OBJECTIVE: To investigate the polarization effect of Malibatol A on oxygen-glucose deprivation (OGD)-BV-2 cells, and the possible molecular mechanism involved in c-Abl-MST signaling pathway. METHOD: The OGD BV-2 cell model was established. BV-2 cells were exposed to OGD for 8 h followed by reperfusion for 15 h with Malibatol A at different concentration of 0.5, 1, 2, 4, 8, 16 µM or without it. And then cells, mRNA and protein were harvested respectively. The cell viability and apoptosis were measured by MTT assay and flow cytometry. The mRNA of classical activated microglia (M1) markers (MCP-1, IL-1 and TNF-α) and alternatively activated microglia (M2) markers (Ym-1, CD206, IL-10, TGF-ß) in BV-2 cells were measured by RT-PCR. Meanwhile, the proteins of Ym-1 and CD206 was assayed by flow cytometry. Furthermore, the expression of c-Abl and MST was measured by Western blot. RESULT: Malibatol A significantly decreased apoptosis and increased viability of OGD BV-2 cells in a dose-dependent manner. In the presence of Malibatol A, the mRNA levels of Ym-1, CD206, IL-10 and TGF-ß mRNA was significantly increased in OGD-BV-2 cells, while the mRNA levels of MCP-1, IL-1 and TNF-α was obviously down-regulated. Meanwhile, the proteins of Ym-1 and CD206 was raised in OGD BV-2 cells with Malibatol A. Besides, Malibatol A also inhibited OGD-induced p-MST1(Y433) in BV-2 cells. CONCLUSION: Malibatol A could attenuate OGD-induced BV-2 cell injury and promote M2 microglia polarization. The mechanism may be related to inhibition of MST1 phosphorylation at Y433.

Oridonin Attenuates Synaptic Loss and Cognitive Deficits in an Aß1-42-Induced Mouse Model of Alzheimer's Disease.

Synaptic loss induced by beta-amyloid (Aß) plays a critical role in the pathophysiology of Alzheimer's disease (AD), but the mechanisms underlying this process remain unknown. In this study, we found that oridonin (Ori) rescued synaptic loss induced by Aß1-42 in vivo and in vitro and attenuated the alterations in dendritic structure and spine density observed in the hippocampus of AD mice. In addition, Ori increased the expression of PSD-95 and synaptophysin and promoted mitochondrial activity in the synaptosomes of AD mice. Ori also activated the BDNF/TrkB/CREB signaling pathway in the hippocampus of AD mice. Furthermore, in the Morris water maze test, Ori reduced latency and searching distance and increased the number of platform crosses in AD mice. These data suggest that Ori might prevent synaptic loss and improve behavioral symptoms in Aß1-42-induced AD mice.

Esculentoside A suppresses Aß(1-42)-induced neuroinflammation by down-regulating MAPKs pathways in vivo.

INTRODUCTION: Esculentoside A (EsA) is a saponin isolated from the roots of Phytolacca esculenta. Previous studies have demonstrated that EsA exerts strong anti-inflammatory effects in peripheral immune inflammation. This study is to determine whether EsA is effective in inflammation-related neurodegenerative diseases, such as Alzheimer's disease (AD). METHODS: Male C57BL/6(B6) mice were divided into three groups of six mice as follows: (1) control group; (2) AD model group (Aß(1-42)-induced AD mice with saline); (3) EsA group (Aß(1-42)-induced AD mice with EsA, 5  mg/kg/day, i.p. for 15 days). Behavioural testing was performed after 15  days of EsA treatment. Real time PCR and Western blot were used to assess the level of inflammation factors and mitogen-activated protein kinases (MAPKs). Immunostaining was used to determine the level of activated microglia and astrocyte. RESULTS: The results showed that EsA attenuated memory deficits in Aß(1-42)-induced AD mice. Esculentoside A decreased the pro-inflammatory factors and microglia and astrocyte activation in the hippocampi of Aß(1-42)-induced AD mice. Moreover, Aß(1-42) activated phosphorylation of ERK, JNK and p38 MAPKs in the hippocampi of mice in the AD model group, while EsA significantly decreased the phosphorylation levels. CONCLUSION: These findings indicate that EsA provides protective effects against neuroinflammation triggered by ß-amyloid.

Orientin alleviates cognitive deficits and oxidative stress in Aß1-42-induced mouse model of Alzheimer's disease.

AIMS: ß-Amyloid (Aß)-mediated neurotoxicity plays a critical role in the pathogenesis of Alzheimer's disease (AD), possibly including Aß-induced mitochondrial dysfunction and oxidative stress. Previous studies have demonstrated that orientin (Ori) possesses antioxidation capabilities in vitro. Therefore, current study is to demonstrate that Ori can activate Nrf2/HO-1 signaling and alleviate apoptosis induced by Aß1-42, and ameliorate cognitive deficits in AD mice. MAIN METHODS: AD models were made by injecting Aß1-42 into the bilateral hippocampus of mice. The mice were randomly assigned to three groups: the normal mice and Aß1-42-induced AD mice with saline, and Aß1-42-induced AD mice with Ori (5mg/kg), and were injected intraperitoneally once a day for 15 days. After the Morris Water Maze (MWM) test, mice were sacrificed and brains were harvested for biochemical analysis. KEY FINDINGS: Results indicated that Ori could ameliorate cognitive deficits in AD mice. Levels of oxidative stress, indicated by production of reactive oxygen species (ROS), 3-nitrotyrosine (3-NT), 4-hydroxy-nonenal (4-HNE) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), were significantly decreased after Ori treatment. In addition, the current study showed that Ori could attenuate mitochondrial dysfunction induced by Aß1-42, and subsequently inhibited the mitochondrial apoptotic pathway. Ori induced the nuclear translocation of Nrf2, which enhanced the expression of HO-1 and activation of the redox signaling pathway. SIGNIFICANCE: Ori might alleviate cognitive deficits and oxidative stress in AD mice, which might be a potential therapeutic drug for AD.

Oridonin attenuates Aß1-42-induced neuroinflammation and inhibits NF-κB pathway.

Neuroinflammation induced by beta-amyloid (Aß) plays a critical role in the pathogenesis of Alzheimer's disease (AD), and inhibiting Aß-induced neuroinflammation serves as a potential strategy for the treatment of AD. Oridonin (Ori), a compound of Rabdosia rubescens, has been shown to exert anti-inflammatory effects. In this study, we demonstrated that Ori inhibited glial activation and decreased the release of inflammatory cytokines in the hippocampus of Aß1-42-induced AD mice. In addition, Ori inhibited the NF-κB pathway and Aß1-42-induced apoptosis. Furthermore, Ori could attenuate memory deficits in Aß1-42-induced AD mice. In conclusion, our study demonstrated that Ori inhibited the neuroinflammation and attenuated memory deficits induced by Aß1-42, suggesting that Ori might be a promising candidate for AD treatment.

TL-2 attenuates ß-amyloid induced neuronal apoptosis through the AKT/GSK-3ß/ß-catenin pathway.

ß-amyloid (Aß)-mediated neuronal apoptosis contributes to the progression of Alzheimer's disease (AD), although the exact mechanism remains unclear. This study aimed to investigate whether Dalesconol B (TL-2), a potent immunosuppressive agent with an unusual carbon skeleton, could inhibit Aß-induced apoptosis in vitro and in vivo and to explore the underlying mechanisms. Aß(1-42) was injected to bilateral hippocampus of mice to make the AD models in vivo. TL-2 was able to cross the blood-brain barrier and attenuate memory deficits in the AD mice. TL-2 also inhibited Aß(1-42)-induced neuronal apoptosis in vitro and in vivo. In addition, TL-2 could activate the AKT/GSK-3ß pathway, and inhibition of AKT and activation of GSK-3ß partially eliminated the neuroprotective effects of TL-2. Furthermore, TL-2 induced the nuclear translocation of ß-catenin and enhanced its transcriptional activity through the AKT/GSK-3ß pathway to promote neuronal survival. These results suggest that TL-2 might be a potential drug for AD treatment.

Diammonium glycyrrhizinate attenuates Aß(1-42) -induced neuroinflammation and regulates MAPK and NF-κB pathways in vitro and in vivo.

BACKGROUND AND PURPOSE: Beta-amyloid (Aß)-mediated inflammation contributes to the progression and chronicity of Alzheimer's disease (AD), although the exact mechanism remains unclear. This study aimed to investigate whether diammonium glycyrrhizinate (DG) could inhibit Aß-induced inflammation in vitro and in vivo and to explore the underlying mechanisms. METHODS: Aß(1-42) was injected to bilateral hippocampus of mice to make the AD models in vivo. The levels of mRNA and protein of inflammatory cytokines were measured by real-time PCR and Western blotting, respectively. The viability of SH-SY5Y and HT-22 cells was determined by MTT. NF-κB p65 translocation was analyzed by Western blotting and immunostaining. Phosphorylation of ERK, p38, and JNK was tested by Western blotting. RESULTS: DG suppressed Aß(1-42) -induced activation of microglia and inflammation in vitro and in vivo. The media from Aß(1-42) -activated microglia decreased the viability of SH-SY5Y and HT-22 cells, but it was rescued when pretreated with DG. DG could inhibit the activation of MAPK and NF-κB signaling pathways and attenuate the memory deficits in Aß(1-42) -induced AD mice. CONCLUSIONS: DG protects Aß(1-42) -induced AD models in vitro and in vivo through reducing activation of microglia and inflammation, which may be involved in MAPK and NF-κB pathways.