English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/17955
Title: Neuroprotective effect of H. perforatum extracts on β-amyloid-induced neurotoxicity
Authors: Silva, Bruno A.; Dias, Alberto C. P.; Ferreres, Federico; Malva, João O.; Oliveira, Catarina R.
Keywords: Alzheimer’s disease
Hypericum perforatum
Amyloid β(25–35)
Hippocampal neurons
Issue Date: Jan-2004
Publisher: Springer
Citation: Neurotoxicity Research 6(2): 119-130 (2004)
Abstract: In the present study we assessed the neuroprotective role of aHypericum perforatum ethanolic extract and obtained fractions in amyloid-β peptide (Aβ)(25–35)-induced cell death in rat cultured hippocampal neurons. Lipid peroxidation was used as a marker of oxidative stress by following the formation of TBARS in rat cortical synaptosomes, after incubation with ascorbate/Fe2+, alone or in the presence of EC97 effective concentrations ofH. perforatum fractions. Induced lipid peroxidation was significantly inhibited by fractions containing flavonol glycosides, flavonol and biflavone aglycones, and by a fraction containing several phenols, mainly chlorogenic acid-type phenolics (21%,77%and 98%, respectively). Lipid peroxidation evaluated after incubation with 25 μM Aβ(25–35), was significantly inhibited byH. perforatum extract. Cell viability was assessed by use of the Syto-13/PI assay. The total ethanolic extract (TE) and fractions containing flavonol glycosides, flavonol and biflavone aglycones, reduced Aβ(25–35)-induced cell death (65%,58%and 59%,respectively). These results were further supported by morphological analysis of cells stained with cresyl violet. Peptide β-amyloid(25–35) induced a decrease in cell volume, chromatin condensation and nuclear fragmentation, alterations not evident in the presence of the TE and fractions containing hypericins (hypericin concentration = 11.02 μM), or fractions containing flavonoids (quercetin concentration = 21.13 μM). Dendritic lesion,an evidence of neurodegeneration, was observed by neuronal staining with cobalt following insult with Aβ(25–35), but prevented after exposure to the peptide plus the fractions referred above. The results of the present paper suggest thatH. perforatum extracts may be endowed with neuroprotective compounds able to prevent Aβ(25–35)-induced toxicity.
Description: 12 pages, 6 figures, 1 table.
Publisher version (URL): http://dx.doi.org/10.1007/BF03033214
URI: http://hdl.handle.net/10261/17955
DOI: 10.1007/BF03033214
ISSN: 1029-8428 (Print)
1476-3524 (Online)
Appears in Collections:(CEBAS) Artículos
Files in This Item:
There are no files associated with this item.
Show full item record

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.