Author(s):
Vieira, Pedro Miguel de Sousa 
; Marques, Belém Sampaio ; Ludovico, Paula ; Dias, Alberto Carlos Pires
Date: 2011
Persistent ID: http://hdl.handle.net/1822/18579
Origin: RepositóriUM - Universidade do Minho
Subject(s): Hypericum perforatum; Toxicity; α-synuclein
Description
Parkinson’s disease (PD), first described by James Parkinson in 1817, is a chronic,
progressive neurodegenerative disorder. The pathologic hallmark is a deterioration of
the substantia nigra of yet unknown causes, resulting in a deficiency of dopamine, an
important neurotransmitter for the basal ganglia circuit and the presence of cytoplasmic
eosinophilic inclusions named Lewy bodies, in which α-synuclein is the major
constituent. Recent work implicates abnormal protein accumulation, protein
phosphorylation, mitochondrial dysfunction and oxidative stress as common pathways
implicated in PD pathogenesis. Polyphenolic compounds are commonly found in both
edible and medicinal plants, and they have been reported to have multiple biological
effects, including antioxidant activity. The budding yeast Saccharomyces cerevisiae has
been used as a model to study several neurodegenerative diseases, including biological
function of α-synuclein, as well as its toxicity. The heterologous expression of wild-type
and A53T mutant form of α-synuclein causes toxicity in cells. Therefore, the aim of this
study was to evaluate the possible protective effect of Hypericum perforatum phenolic
compounds (quercetin, kaempferol and biapigenine), in the toxicity induced by the
heterologous expression of α-synuclein, using the yeast Saccharomyces cerevisiae as a
model. Preliminary results indicate that the presence of these phenolic compounds
decrease the protein accumulation in cells expressing α-synuclein. We concluded that
these phenolic compounds apparently have beneficial biological properties that
consequently could have a potential use in preventing Parkinson’s disease.
