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Objective:To investigate the effect of analgecine (AGC) on inflammatory response in the cell model of ischemic stroke and its mechanism. Methods:Sodium hydrosulfite (Na2S2O2) combined with sugar-free culture-medium was used to stimulate the model of ischemic stroke in vitro. BV2 cells were divided into six groups: control group, control with 0.5 U/ml AGC group, oxygen deprivation and recovery (OGD/R) group, OGD/R with AGC (0.25 U/ml, 0.5 U/ml, 1 U/ml) groups. After oxygen and glucose deprivation for 1.5 hours, they were changed to normal medium and given different concentrations of AGC in OGD/R with AGC groups. After co-incubation for three hours, the cells were treated. The content of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the supernatant was detected. The expression of M1-type microglia marker CD16+CD32 and M2-type microglia marker CD206 were detected with immunofluorescent staining. BV2 cells were divided into seven groups: control group, control with 0.5 U/ml AGC group, IL-4 group, IL-4 + lipopolysaccharide (LPS) + interferon (IFN)-γ group, IL-4 + LPS + IFN-γ with AGC (0.25 U/ml, 0.5 U/ml, 1 U/ml) groups. After 24 hours of IL-4 treatment, LPS + IFN-γ were added for 18 hours, they were changed to normal medium and given different concentrations of AGC for 24 hours, the expression of CD16+CD32 and CD206 were observed by flow cytometry. Results:Compared with the control group, the IL-6 and TNF-α level increased (P < 0.01), the number of CD16++CD32+ increased and the number of CD206+ decreased in OGD/R group. Compared with the OGD/R group, the IL-6 and TNF-α level decreased (P < 0.01), the number of CD16++CD32+ decreased and the number of CD206+ increased in AGC groups. Compared with the control group, the number of CD206 tended to increase, and the number of CD16+CD32 tended to decrease in IL-4 group; compared with IL-4 group, the number of CD16+CD32 tended to increase, and the number of CD206 tended to decrease in IL-4 + LPS + IFN-γ group; compared with IL-4 + LPS + IFN-γ group, the number of CD16+CD32 tended to decrease, and the number of CD206 tended to increase in IL-4 + LPS + IFN-γ + 0.25 U/ml AGC group and IL-4 + LPS + IFN-γ + 0.5 U/ml AGC group, while the number of CD206 increased in IL-4 + LPS + IFN-γ + 1.0 U/ml AGC group (P < 0.05). Conclusion:AGC could inhibit the secretion of inflammation factors by promoting the polarization of microglia from M1 phenotype to M2 phenotype.
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Alzheimer's disease (AD) is one of the most common neurodegenerative diseases, which is characterized by cognitive and memory dysfunction. Calpain is widely activated in cells. Disturbance of calpain is currently thought to a main cause of hyperphosphorylation and abnormal cleavage of tau protein in AD pathology. Calpain affects the activities of glycogen synthase kinase 3 and protein phosphatase 2A, which causes abnormal hyperphosphorylation of multiple sites of tau protein, and mediates truncation of tau protein monomers, and induces neurodegeneration. Calpain is expected to be a potential target for drug therapy of AD.
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Objective: Alzheimer's disease (AD) is along with cognitive decline due to amyloid-β (Aβ) plaques, tau hyperphosphorylation, and neuron loss. Shenqi Xingnao Granules (SQXN), a traditional Chinese medicine, significantly ameliorated the cognitive function and daily living abilities of patients with AD. However, till date, no study has investigated the mechanism of action of SQXN on AD. The present study aimed to verify the effects of SQXN treatment on cognitive impairments and AD-like pathologies in APP/PS1 mice. Methods: Four-month-old APP/PS1 transgenic (Tg) mice were randomly divided into a model group and SQXN-treated (3.5, 7, 14 g/kg per day) groups. Learning-memory abilities were determined by Morris water maze and object recognition test. All mice were sacrificed and the brain samples were collected after 75 d. The soluble Aβ contents were detected by Elisa kit; The levels of expression of NeuN, APP, phosphorylated tau and related protein were measured by Western blotting; The inflammation factors were detected by the proinflammatory panel kit. Results: Four-month-old APP/PS1 mice were administered SQXN by oral gavage for 2.5 months. Using the Morris water maze tests and Novel object recognition, we found that SQXN restored behavioral deficits in the experimental group of Tg mice when compared with the controls. SQXN also inhibited neuronal loss (NeuN marker). SQXN treatment decreased soluble Aβ42 through inhibiting the expression of sAPPβ and BACE-1 without regulating full-length amyloid precursor protein (FL APP). Insulin degrading enzyme (IDE), the Aβ degrading enzyme, were increased by SQXN. In addition, SQXN reduced hyperphosphorylated tau protein levels and prevented excessive activation of p-GSK-3β in the brain of APP/PS1 mice. Compared with APP/PS1 transgenic negative mice, IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-12p70, KC/GRO and TNF-α were not obviously changed in the brain of 6.5-month-old APP/PS1 transgenic (Tg) mice. However, SQXN could inhibited the expression of IL-2. Conclusion: These results demonstrate that SQXN ameliorates the cognitive impairments in APP/PS1 mice. The possible mechanisms involve its inhibition of neuronal loss, soluble Aβ deposition, tau hyperphosphorylation and inflammation.
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Objective To investigate the effects of cornel iridoid glycoside (CIG) on the learning-memory ability and pathological changes in the brain of vascular dementia (VD) rats; To discuss relevant mechanism of action. Methods SD rats were randomly divided into sham-operation group, model group, positive medicine group, CIG groups low-, medium- and high-dose groups. The animal model of VD was replicated by permanent bilateral common carotid artery occlusion (2VO) in rats. Drugs were intragastrically administered 6 h after surgery and then once a day for 3 months. Morris water maze test was used to detect spatial learning-memory ability, and recognition memory was measured by the object recognition test. Immunohistochemical staining was used to detect the neuronal survival and the expression of choline acetyltransferase (ChAT) in the brain. Results Three months after permanent 2VO operation, the model rats showed a longer escape latency in Morris water maze, a lower discrimination index in the object recognition test, and a decrease in NeuN positive neuronal survival and ChAT expression in the hippocampus and cerebral cortex. Compared with the model group, intragastric administration of CIG for 3 months shortened the escape latency in Morris water maze, elevated the discrimination index in the object recognition test, and increased the NeuN positive neuronal survival in the hippocampus and cerebral cortex and ChAT expression of 2VO rats. Conclusion CIG can improve the cognitive impairment of VD model rats through protecting neurons and promoting ChAT expression.
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Objective To observe the effects of Shenqi Xingnao Prescription on learning and memory ability, contents of choline acetyltransferase (ChAT) and acetylcholine esterase (AChE) in brain tissue in mice models with scopolamine-induced Alzheimer disease (AD); To investigate its mechanism for prevention and treatment for AD. Methods Totally 110 ICR mice were randomly divided into control group, control+Shenqi Xingnao Prescription high-dose group,model group,donepezil group,model+Shenqi Xingnao Prescription high-,medium-,and low-dose groups. The control and model group were given distilled water for gavage, and the other groups were given the corresponding medicine for gavage, once a day, for 14 days. On the 15th day, Morris water maze test and object recognition test were used to evaluate the learning and memory ability of each group. The model mice of memory impairment induced by intraperitoneal injection of scopolamine was established 20 minutes before the behavioral test. The expressions of ChAT and AChE in cortex and hippocampus were detected by Western blot. Results The results of Morris water maze test showed that compared with the control group, the model group had significant longer escape latency(P<0.05);Compared with the model group,Shenqi Xingnao Prescription medium-and high-dose groups could shorten the escape latency (P<0.05). The results of the object recognition test showed that compared with the control group, the ability of the model group to explore new things decreased and the discrimination index (DI) decreased (P<0.001);Compared with the model group,Shenqi Xingnao Prescription groups could increase the DI of model mice (P<0.05, P<0.01, P<0.001). The results of Western blot showed that the expression of AChE protein in the cortex and hippocampus of the model group was significantly higher than the control group (P<0.01); Compared with the model group, Shenqi Xingnao Prescription low- and medium-dose groups could decrease the expression of AChE in the cortex in different degrees(P<0.01);Shenqi Xingnao Prescription groups could decreaed the expression of AChE in the hippocampus (P<0.001); There was no significant statistical significance in the expression of ChAT in the cortex and hippocampus in each group.Conclusion Shenqi Xingnao Prescription can significantly improve the learning and memory ability of AD model mice induced by scopolamine, which may be related to the descent expression of AChE protein in the cortex and hippocampus of the model mice.
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Alzheimer's disease (AD) is the most common neurodegenerative disease in the aging population. Abnormal hyperphosphorylation of tau is the main cause of AD. Protein phosphatases 2A (PP2A) can increase the hyperphosphorylation of tau. Cornel iridoid glycoside (CIG) is one of the main components extracted from Cornus of ficinalis. The aim of the present study was to investigate the effects and the underlying mechanisms of CIG on enhancing PP2A activity. SK-N-SH cells were exposed to 20 nmol·L-1 okadaic acid (OA, an inhibitor of PP2A) for 6 h to induce the hyper-phosphorylation of tau, in order to define the effect of CIG on the activity of PP2A and posttranslational modification of PP2A catalytic subunit C (PP2Ac). We found that OA significantly decreased PP2A activity, increased the phosphorylation of PP2Ac, and enhanced tau hyper-phosphorylation. Pre-incubation of CIG significantly attenuated the OA-induced tau hyper-phosphorylation at Ser 199/202 and Ser 396, and recovered the activity of PP2A. CIG inhibited PP2Ac phosphorylation at Tyr 307 and increased Src phosphorylation. In conclusion, the mechanism of CIG inhibition of tau hyper-phosphorylation was activation of PP2A to reduce the level of p-Src for a reduction of PP2Ac phosphorylation at Tyr307.
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@#Objective To observe the effects of 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glycoside (TSG) on formation of senile plaques and beta amyloid (Aβ), as well as activation of microglia and astrocytes, in cortex and hippocampus of APP/PS1 double transgenic mice. Methods A total of 64 five-month-old APP/PS1 mice were randomly divided into model group (n=16), low-dose TSG (0.05 g/kg) group (n=16), high-dose TSG (0.1 g/kg) group (n=16), and donepezil group (n=16); other 32 same age wild type (WT) mice were randomly divided into normal control group (n=16) and high-dose TSG (0.1 g/kg) WT group (n=16). The normal control group and model group were given distilled water, and the other groups were given the corresponding drugs intragastrically. The mice were tested with object recognition test, the deposi-tion of plaques in brain was detected with Congo red staining, and the expression of Aβ40/42, ionized calcium bind-ing adapter molecule 1 (Iba1) and glial fibrillary acidic protein (GFAP) with immunohistochemistry after seven months of treatment (twelve-month-old). Results Compared with the model group, the discrimination index significantly increased (P<0.01), the deposition of plaques decreased in brain (P<0.05), and the expression of Aβ40/42, Iba1 and GFAP all significantly decreased in each treatment group (P<0.05). Conclusion TSG can improve learning and memory of APP/PS1 transgenic mice, reduce Aβ deposition and senile plaques, and reduce the inflammatory response, even in low-dose, which is similar to that of donepezil.