Effect of GAPT extract on expression of tau protein and its phosphorylation related enzymes in hippocampal neurons of APPV717I transgenic mice / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of GAPT, an extract mixture from Radix Ginseng, Rhizoma Acor tatarinowii, Radix Polygalae and Radix Curcuma (containing ingredient of turmeric), etc. on expression of tau protein and its phosphorylation related enzyme in hippocampal neurons of APPV717I transgenic mice.</p><p><b>METHODS</b>Sixty three-month-old APPV717I transgenic mice were randomly divided into model group, donepezil group [0.92 mg/(kg•d)], the low, medium and high dosage of GAPT groups [0.075, 0.15, 0.30 g/(kg•d), 12 in each group], and 12 three-month-old C57BL/6J mice were set as a normal control group, treatments were administered orally once a day respectively, and both the normal group and model group were given 0.5% sodium carboxymethyl cellulose solution. Immunohistochemistry (IHC) and Western blot analysis were used to detect the expression of total tau protein (Tau-5), cyclin-dependent kinase 5 (CDK5) and protein phosphatase 2A (PP2A) in hippocampal neurons of experimental mice after 8-month drug administration (11 months old).</p><p><b>RESULTS</b>In the model group, the expression of Tau-5 and CDK5 were increased, whereas the expression of PP2A was decreased in hippocampal neurons, which were signifificantly different compared with that in the normal group (all P<0.01). IHC test indicated the number and area of either Tau-5 or CDK5 positive cells were decreased with a dose-depended way in GAPT groups, and an increase of PP2A. Compared with the model group, the changes were signifificant in GAPT groups (P<0.05 or P<0.01). Similar results were shown by Western blot.</p><p><b>CONCLUSION</b>GAPT could attenuate abnormal hyperphosphorylation of tau protein in hippocampal neurons of APPV717I transgenic mice via inhibiting the expression of CDK5 and activating the expression of PP2A.</p>

Neuroprotective effect of curcumin to Aβ of double transgenic mice with Alzheimer's disease / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the changes in Aβ40, Aβ42 and ADDLs in brains of 3 month-old APPswe/PS1dE9 double transgenic mice after six-month intervention with curcumin, in order to discuss the neuroprotective effect of curcumin.</p><p><b>METHOD</b>APPswe/PS1dE9dtg mice were randomly divided into the model group, the Rosiglitazone group (10 mg x kg(-1) x d(-1)) and curcumin high (400 mg x kg9-1) x d(-1)), medium (200 mg x kg(-1) x d(-1)) and low (100 mg x kg(-1) x d(-1)) dosage groups, with C57/BL6J mice of the same age and the same background in the normal control group. After 6 months, the immunohistochemical staining (IHC) and the Western blot method were used to observe the changes in positive cell of Aβ40, Aβ42 and ADDLs in hippocampal CA1 area, their distribution and protein expressions.</p><p><b>RESULT</b>Both of the immunohistochemical staining and the Western blot method showed more positive cell of Aβ40, Aβ42 and ADDLs in hippocampal CA1 area and higher protein expressions in the model group than the normal group (P < 0.01). IHC showed a lower result in the Rosiglitazone group than the model group (P < 0.05), while Western blot showed a much lower result (P < 0.01). The number of Aβ40, Aβ42 and ADDLs positive cells and the protein expressions decreased in the curcumin high group, the medium group showed a significant decrease (P < 0.01), and the low dose group also showed reductions in the protein expressions of Aβ40 and Aβ42.</p><p><b>CONCLUSION</b>The six-month intervention with curcumin can significantly reduce the expressions of hippocampal Aβ40, Aβ42 and ADDLs in brains of APPswe/PS1dE9 double transgenic mice. Whether curcumin can impact Aβ cascade reaction by down-regulating expressions of Aβ40, Aβ42 and ADDLs and show the neuroprotective effect needs further studies.</p>

Effect of curcumin on expression of AKT and p-AKT in hippocampus CA1 area of App/PS1 double transgenic mice / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of curcumin on the expressions of AKT (serine-threonine kinase, AKT, also known as PKB) and p-AKT (phosphated serine-threonine kinase, p-AKT) in APP/PS1 double transgenic mice of the AD model.</p><p><b>METHOD</b>Three-month-old APP/PS1 double transgenic mice were randomly divided into the model group, the rosiglitazone (10 mg kg-1 . d-1) group, and high (400 mg . kg-1 d-1), medium (200 mg . kg-1 d-1) and low (100 mg kg-1 d-1) dosecurcumin groups. Non-transgenic mice of the same age and background were selected as the control group ( n = 12). After all of the six groups were intragastrically administered for consecutively three months, the protein expressions of AKT and p-AKT in hippocampus CA1 area were detected by immunohistochemistry and Western blot.</p><p><b>RESULT</b>The results of immunohistochemistry showed that the expression of AKT and p-AKT positive cells in hippocampus CA1 area significantly decreased in the model group (P <0. 05 and P < 0. 01). Compared with the model group, AKT and p-AKT positive cells of hippocampus CA1 area increased obviously in the rosiglitazone group and high and medium dose curcumin group (P <0.05 or P <0.01) ,especially the medium dose group (P <0.01). The results of Western blot were consistent with that of immunohistochemistry.</p><p><b>CONCLUSION</b>Curcumin can recover the decreased AKT and p-AKT cells in hippocampus CAl area of APP/PS1 double transgenic mice of the AD model, suggesting that curcumin may regulate AKT and its phosphorylation process, as well as PI3K/AKT insulin signal transduction pathway, and show the anti-AD effect.</p>

Effect of curcumin on hippocampal IRS-1 and p-IRS-1 expressions in APP/PS1 double transgenic mice / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of curcumin on the expressions of insulin receptor substrate-1 (IRS-1) and phosphated insulin receptor substrate-1 (p-IRS-1I) in APP/PS1 double transgenic mice of the AD model.</p><p><b>METHOD</b>Three-month-old APP/ PSI double transgenic mice were randomly divided into the model group, the positive rosiglitazone control group and curcumin high (400 mg . kg-1 . d-1), medium (200 mg . kg-1 . d-1) and low (100 mg . kg-1 . d-1) dose groups. The normal group was composed of non-transgenic mice under the same background. After they were orally administered for three months, they were detected with immunohistochemistry, Western blot and RT-PCR.</p><p><b>RESULT</b>According to IRS-1 and p-IRS-1 immumohistochemical staining, the expression of IRS-1 positive cells in hippocampus CA1 area in model mice was significantly higher than that of the normal control group (P<0. 01). Compared with the model group, the number of IRS-1 positive cells in hippocampus CA1 area decreased (P <0. 05 or P <0. 01) and the number of p-IRS-1 positive cells in hippocampus CA1 area increased in all of curcumin intervention groups. Western blot results were consistent with IRS-1 and p-IRS-1 protein expressions and immunohistochemistry results. RT-PCR test showed opposite IRS-1 mRNA expression results with immunohistochemistry and Western blot results.</p><p><b>CONCLUSION</b>Curcumin can recover increased IRS-1 and decreased p-IRS-1 in hippocampus of APP/PS1 double transgenic mice, increase IRS-1 mRNA expression, and improve the insulin-signaling transduction in APP/PS1 double transgenic mice. This suggests that curcumin can regulate the insulin-signaling transduction mechanism and show an anti-AD effect.</p>

Effects of curcumin on expression of PI3K and p-pI3K in hippocampus of AD mice / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effect of curcumin on the expression of PI3K (phosphatidylinositol-3-kinase, PI3K) and p-P3 K (phosphated phosphatidylinositol-3-kinase, p-PI3K) in the hippocampus of Alzheimer's disease (AD) model (APP/PS1 double transgenic) mice.</p><p><b>METHOD</b>A total of 60 three-month-old APP/PS1 double transgenic mice were randomly divided into model group, rosiglitazone group(10 mg . kg-1 . d-1) and curcumin large(400 mg . kg-1 . d-1), medium(200 mg- kg-1 . d-1) and small(100 mg . kg-1 . d-1) dose group. Twelve C57BL/6J mice in the same age and genetic background as APP/PS1 double transgenic mice were used as normal control group. All the 6 groups of mice were intragastrically administered for 3 months. After 3 months, the expression of PI3K and p-PI3K were detected by immunohistochemistry and Western blot.</p><p><b>RESULT</b>The expression of PI3K and p-PI3K positive cells in hippocampus CA1 region significantly decreased in model group compared with normal control group (P < 0. 05) , while compared with model group, PI3K and p-PI3K positive cells of all the curcumin intervention groups increased to varying degrees in hippocampus CA1 region,especially the middle dose group(P <0. 01). Besides,Western blot results of the curcumin high dose group were also increased obviously (P <0. 05).</p><p><b>CONCLUSION</b>Curcumin can recover the decreased PI3K and p-PI3K and improve the insulin-signaling transmission in the hippocampus of APP/PS1 double transgenic mice. The mechanism of curcumin maybe by regulating the insulin signal transduction to treat AD.</p>

Dynamic effect of curcumin on urine concentration of neuronal thread protein in AD mice / 中国中药杂志

<p><b>OBJECTIVE</b>Through the dynamic detection of the concentration change of the urine Alzheimer-associated neuronal thread protein (AD7C-NTP) in the curcumin treated Alzheimer's disease (AD) model (APP/PS1 double transgenic) mice, the therapeutic effect of curcumin in AD was determined.</p><p><b>METHOD</b>Thirty three-month-old APP /PS1 double transgenic mice were randomly divided into 5 groups, 6 in each group, the model group, rosiglitazone group(10 mg . kg-1 . d-1) , high(400 mg . kg -1 . d-1) , medium(200 mg . kg-1. d-1) and low(100 mg . kg-1 . d-1) dose curcumin groups. Six C57BL/6J mice in the same age and genetic background were used as normal control group. All the 6 groups of mice were intragastrically administered for 6 months. Urine samples were collected on 4 month, 5 month and 6 month after intragastric administration, respectively. The changes of urinary AD7C-NTP concentration were detected by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULT</b>The concentration of AD7C-NTP of each group was compared at the same time point, the concentration of model group is higher than normal control group (P <0.05) ; the concentration of other groups is lower than model group. The concentration of high curcumin dose group with 4 months treatment, has no statistical difference compared with model group. The AD7C-NTP concentration of each group was elevated with the age growth, and all concentrations of the treatment groups were lower than the model group at the same period. With the treatment of 4, 5 and 6 months, the concentration of the normal control group has significant difference with the treatment groups(P <0. 01). There have no statistical difference between all the groups with the treatment of 6 months compared with 5 months.</p><p><b>CONCLUSION</b>With the progression of the disease in AD mice, there are fluctuations in urinary AD7C-NTP concentration, the compound curcumin from traditional Chinese medicine can delay the progression of AD.</p>