Methods of reducing beta-amyloid polypeptides

Abstract

The invention features methods of reducing the level of a β-amyloid (Aβ) polypeptide using an Cimicifuga extract. The invention also features methods of producing an active fraction from an extract of Cimicifuga. The invention further features a composition containing an active fraction of a Cimicifuga extract and an article of manufacture containing such a composition.

What is claimed is:  
     
         1 . A method of reducing the level of a β-amyloid (Aβ) polypeptide in or secreted from a cell, said method comprising contacting said cell with an amount of a Cimicifuga extract or of an active fraction thereof effective for reducing the level of said Aβ polypeptide in or secreted from said cell and monitoring the level of said Aβ polypeptide in or secreted from said cell.  
     
     
         2 . The method of  claim 1 , wherein said Cimicifuga extract or active fraction thereof is from  C. racemosa.    
     
     
         3 . The method of  claim 2 , wherein said  C. racemosa  extract or active fraction thereof is obtained from the root or rhizome of a  C. racemosa  plant.  
     
     
         4 . The method of  claim 2 , wherein said  C. racemosa  extract is an ethanolic extract or an aqueous extract.  
     
     
         5 . The method of  claim 2 , wherein an active component within said active fraction is soluble in a solvent selected from the group consisting of methylene dichloride, ethyl acetate and n-butanol.  
     
     
         6 . The method of  claim 5 , wherein said active component is lipophilic.  
     
     
         7 . The method of  claim 2 , wherein an active component within said active fraction has a molecular weight of less than 10 kD.  
     
     
         8 . The method of  claim 1 , wherein said cell is selected from the group consisting of H4 cells, M17 cells, 293 cells, Chinese hamster ovary (CHO) cells, primary fibroblasts, C6, primary neuronal, primary mixed brain cultures, Daoy, SK-N-SH, SK-N-AS and SK-NFI.  
     
     
         9 . The method of  claim 1 , wherein said reduction in the level of said Aβ polypeptide is due to decreased production of said Aβ polypeptide or increased catabolism of said Aβ polypeptide.  
     
     
         10 . The method of  claim 1 , wherein said level of said Aβ polypeptide is reduced by at least 10% compared to the level of said Aβ polypeptide in or secreted from a corresponding cell not contacted with said extract or active fraction thereof.  
     
     
         11 . The method of  claim 1 , wherein said level of said Aβ polypeptide is reduced by at least 25% compared to the level of said Aβ polypeptide in or secreted from a corresponding cell not contacted with said extract or active fraction thereof.  
     
     
         12 . The method of  claim 1 , wherein said level of said Aβ polypeptide is reduced by at least 50% compared to the level of said Aβ polypeptide in or secreted from a corresponding cell not contacted with said extract or active fraction thereof.  
     
     
         13 . The method of  claim 1 , wherein said level of said Aβ polypeptide is reduced by at least 80% compared to the level of said Aβ polypeptide in or secreted from a corresponding cell not contacted with said extract or active fraction thereof.  
     
     
         14 . The method of  claim 1 , wherein said Aβ polypeptide is Aβ40.  
     
     
         15 . The method of  claim 1 , wherein said Aβ polypeptide is Aβ42.  
     
     
         16 . The method of  claim 1 , wherein said reduction is preferential for Aβ42.  
     
     
         17 . The method of  claim 1 , wherein said extract or active fraction thereof has no significant effect on the level of one or more of APP, CTFα, CTFβ, or sAPPα.  
     
     
         18 . A method for reducing the level of an Aβ polypeptide in a mammal, said method comprising administering an amount of a Cimicifuga extract or an active fraction thereof to said mammal effective for reducing the level of said Aβ polypeptide and monitoring the level of said Aβ polypeptide in said mammal.  
     
     
         19 . The method of  claim 18 , wherein said extract or active fraction thereof is administered to said mammal orally, intravenously, intracranially, intracerebrally, subcutaneously, intramuscularly, intranasally or intraperitoneally.  
     
     
         20 . The method of  claim 18 , wherein said mammal is a rodent.  
     
     
         21 . The method of  claim 20 , wherein said rodent is a mouse.  
     
     
         22 . The method of  claim 21 , wherein said mouse expresses an APP carrying a Swedish mutation.  
     
     
         23 . The method of  claim 22 , wherein said mouse is a Tg2576 mouse.  
     
     
         24 . A method of treating a mammal having AD or at risk to develop AD, said method comprising administering an amount of a Cimicifuga extract or an active fraction thereof to said mammal effective for treating or preventing AD in said mammal.  
     
     
         25 . A method of producing an active fraction of a Cimicifuga extract, wherein said active fraction reduces the level of an Aβ polypeptide upon contact with a cell producing said Aβ polypeptide, said method comprising: 
 obtaining an extract of Cimicifuga plant material;  
 size-fractionating said extract through a filter to obtain an active fraction, wherein said active fraction comprises active components having a molecular weight of less than about 10 kD; and  
 testing said active fraction to confirm that said active fraction reduces the level of said Aβ polypeptide upon contact with said cell producing said Aβ polypeptide.  
 
     
     
         26 . A method of producing an active fraction of a Cimicifuga extract, wherein said active fraction reduces the level of an Aβ polypeptide upon contact with a cell producing said Aβ polypeptide, said method comprising: 
 obtaining an extract of Cimicifuga plant material;  
 extracting said Cimicifuga extract with hexane, thereby producing a hexane-soluble fraction and a hexane-insoluble fraction; and  
 testing said hexane-insoluble fraction to confirm that said hexane-insoluble fraction reduces the level of said Aβ polypeptide upon contact with said cell producing said Aβ polypeptide.  
 
     
     
         27 . The method of  claim 26 , wherein said hexane is n-hexane.  
     
     
         28 . The method of  claim 26 , further comprising: 
 extracting said hexane-insoluble fraction with a dichloroalkane, thereby producing a dichloroalkane-soluble fraction and a dichloroalkane-insoluble fraction, 
 wherein said dichloroalkane-soluble fraction reduces the level of said Aβ polypeptide upon contact with said cell producing said Aβ polypeptide.  
   
     
     
         29 . The method of  claim 28 , wherein said dichloroalkane is methylene dichloride.  
     
     
         30 . The method of  claim 28 , further comprising: 
 extracting said dichloroalkane-soluble fraction with an alkylacetate, thereby producing an alkylacetate-soluble fraction and an alkylacetate-insoluble fraction, 
 wherein said alkylacetate-soluble fraction reduces the level of said Aβ polypeptide upon contact with said cell producing said Aβ polypeptide.  
   
     
     
         31 . The method of  claim 30 , wherein said alkylacetate is ethyl acetate.  
     
     
         32 . The method of  claim 30 , further comprising: 
 extracting said alkylacetate-soluble fraction with an alcohol, thereby producing an alcohol-soluble fraction and an alcohol-insoluble fraction, 
 wherein said alcohol-soluble fraction reduces the level of said Aβ polypeptide upon contact with said cell producing said Aβ polypeptide.  
   
     
     
         33 . The method of  claim 32 , wherein said alcohol is n-butanol.  
     
     
         34 . The method of  claim 26 , further comprising concentrating said Cimicifuga extract prior to said extraction with hexane, wherein said concentrating comprises lyophilizing said Cimicifuga extract.  
     
     
         35 . A composition, said composition comprising: 
 an active fraction of a Cimicifuga extract and a pharmaceutically acceptable carrier, wherein said active fraction reduces the level of an Aβ polypeptide upon contact with a cell producing said Aβ polypeptide.    
     
     
         36 . An article of manufacture, said article comprising: 
 an active fraction of a Cimicifuga extract, wherein said active fraction reduces the level of an Aβ polypeptide upon contact with a cell producing said Aβ polypeptide;    a pharmaceutically acceptable carrier; and    packaging material, wherein said packaging material contains a label or package insert indicating that said composition is effective for reducing the level of an Aβ polypeptide.