ABSTRACT
This study was aimed to investigate the effect of Chrysophanol (CHR) on Alzheimer's disease. We also attempted to understand the potential mechanisms. An Alzheimer's disease rat model was established using an intraperitoneal injection of d-galactose combined with an intracerebral injection of amyloid-ß peptide (25-35), and the effect of CHR on the learning and memory ability, the hippocampal neurons change, the ultrastructure of the hippocampal CA1 region, the protein levels of CaM, CaMKK, CaMKIV, p-CaMKIV and p-tau in the hippocampus of rats were studied. The results showed that CHR significantly improved the cognitive deficits, alleviated hippocampal neurons damage, prevented the ultrastructure alteration of neurons in hippocampal CA1 region, and reduced the protein levels of CaM, CaMKK, p-CaMKIV and p-tau in the hippocampus of AD rats. These results suggested that Chrysophanol could improve memory ability of Alzheimer's disease rat by inhibiting tau hyperphosphorylation and the CaM-CaMKIV signal pathway.
ABSTRACT
Genistein is a kind of isoflavone compoundsï¼ also called phytoestrogensï¼ with clinical effects on cardiovascular diseaseï¼ cancer and postmenopausal-related gynecological diseasesï¼ and also has the potentiality in the prevention and treatment of Alzheimer's disease(AD). In this studyï¼ the protective effect of genistein on Aß25â35-induced PC12 cell injury and effect on CaM-CaMKIV signaling pathway were observed to investigate its mechanism for AD. PC12 cells were cultured in vitro and then the safe concentration of genistein and the modeling concentration and optimal time point of administration of Aß25â35 were screened by MTT assay. After being pretreated with different concentrations of genistein(25ï¼ 50ï¼ 100 µmol·L⻹) on PC12 cellsï¼ the AD model of PC12 cells was induced by Aß25â35. Then the survival rate of cells was detected by MTT assay; morphological change of cells was observed under the inverted microscopeï¼ and apoptosis of cells was assessed by AO/EB fluorescence staining; the neuroprotective effects of genistein on AD cell model were observed and the optimal concentration of genistein was determined. Expressions of mRNA and protein levels of CaMï¼ CaMKKï¼ CaMKIV and tau were detected by qRT-PCR and Western blot assayï¼ respectively. The results showed that as compared with the blank groupï¼ the cell survival rate was decreased; the cell damage and apoptosis were increased; and the expressions of mRNA and protein levels of CaMï¼ CaMKKï¼ CaMKIV and tau were increased in AD model group. Genistein could significantly improve the cell survival rateï¼ reduce the cell damage and apoptosis of AD cell modelï¼ and significantly down-regulate the expressions of mRNA and protein levels of CaMï¼ CaMKKï¼ CaMKIV and tau of AD cell model. These results indicated that genistein has obviously neuroprotective effect on the AD cell model induced by Aß25â35ï¼ and the mechanism may be related to the down-regulation of CaM-CaMKIV signaling pathway and Tau protein expression.
Subject(s)
Amyloid beta-Peptides , Calcium-Calmodulin-Dependent Protein Kinase Type 4/metabolism , Calmodulin/metabolism , Genistein/pharmacology , Peptide Fragments , Protective Agents/pharmacology , Signal Transduction/drug effects , Animals , Apoptosis , Cell Survival , PC12 Cells , RatsABSTRACT
Genistein is a kind of isoflavone compounds, also called phytoestrogens, with clinical effects on cardiovascular disease, cancer and postmenopausal-related gynecological diseases, and also has the potentiality in the prevention and treatment of Alzheimer's disease(AD). In this study, the protective effect of genistein on Aβ₂₅₋₃₅-induced PC12 cell injury and effect on CaM-CaMKIV signaling pathway were observed to investigate its mechanism for AD. PC12 cells were cultured and then the safe concentration of genistein and the modeling concentration and optimal time point of administration of Aβ₂₅₋₃₅ were screened by MTT assay. After being pretreated with different concentrations of genistein(25, 50, 100 μmol·L⁻¹) on PC12 cells, the AD model of PC12 cells was induced by Aβ₂₅₋₃₅. Then the survival rate of cells was detected by MTT assay; morphological change of cells was observed under the inverted microscope, and apoptosis of cells was assessed by AO/EB fluorescence staining; the neuroprotective effects of genistein on AD cell model were observed and the optimal concentration of genistein was determined. Expressions of mRNA and protein levels of CaM, CaMKK, CaMKIV and tau were detected by qRT-PCR and Western blot assay, respectively. The results showed that as compared with the blank group, the cell survival rate was decreased; the cell damage and apoptosis were increased; and the expressions of mRNA and protein levels of CaM, CaMKK, CaMKIV and tau were increased in AD model group. Genistein could significantly improve the cell survival rate, reduce the cell damage and apoptosis of AD cell model, and significantly down-regulate the expressions of mRNA and protein levels of CaM, CaMKK, CaMKIV and tau of AD cell model. These results indicated that genistein has obviously neuroprotective effect on the AD cell model induced by Aβ₂₅₋₃₅, and the mechanism may be related to the down-regulation of CaM-CaMKIV signaling pathway and Tau protein expression.