The Effect Of Dendrobium Nobile Lindl.Alkaloids On Aβ And Its Related Secretase In The Hippocampus

Objective: To investigate effects of Dendrobium nobile Lindl.alkaloids(DNLA)on α,β and γ-secretase of hippocampal neurons in SD Rat.Methods: Primary hippocampal neurons of rat were cultured till the 8th day.Neurons purity was detected by immunofluorescence technique.The neurons were exposed to DNLA(0.35、3.5、35、350、700 ng/m L,respectively),then cultured for another 48 h and used for further detection.The cell viability was measured by methylthiazoldiphenyl tetrazolium(MTT)assay.Western Blot measured the protein expression of APP,α-secretase(ADAM10 and ADAM17),β-secretase(BACE1),γ-secretase(PS1)and Aβ42.Results: Neurons purity was,at least,84.5%.The cell viability of hippocampal neurons was not changed significantly after the treatment with DNLA.DNLA reduced the protein expression of APP,ADAM10,BACE1 and Aβ42 of hippocampal neurons,increased the protein expression of ADAM17 and PS1,but the PS1 not significantly.Conclusion: Under the experimental conditions,DNLA reduced the protein expression of APP,ADAM10,BACE1 of hippocampal neurons in rat,increased the protein expression of ADAM17.And then reduced the protein expression of Aβ42.Objective: To investigate the effects of Dendrobium nobile Lindl.Alkaloids(DNLA)on the protein expression of APP,BACE1 and Aβ42 of hippocampus in db/db mice.Methods: Male C57BL/Ks J mice were control group.And male db/db mice were devided randomly into four groups: model,DNLA-L(20 mg/kg),DNLA-M(40 mg/kg)and DNLAH(80 mg/kg).After mice were treated with different concentration DNLA by gavaged for 17 weeks,the protein expression of amyloid precursor protein(APP),β-site amyloid precursor protein-cleaving enzyme 1(BACE1)and β-amyloid 42(Aβ42)were examined by Western Blotting.Results: Compared with control group,the protein expression of APP,BACE1 and Aβ42 was significantly increased in hippocampus of model group.Moreover,DNLA decreased significantly the protein expression of APP,BACE1 and Aβ42 of hippocampus in db/db mice compared with model group,and decreased with a dose-dependent manner.Conclusion: Under the experimental conditions,DNLA can decrease the protein expressions of Aβ42 of hippocampus in db/db mice.The mechanism may be involved the decrease of BACE1 and APP.