TY - JOUR
T1 - Protective effects of baicalein against excess L-DOPA-induced dopamine quinone neurotoxicity
AU - Takeshima, Mika
AU - Murata, Maiko
AU - Urasoe, Natsuho
AU - Murakami, Shinki
AU - Miyazaki, Ikuko
AU - Asanuma, Masato
AU - Kita, Taizo
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2011/12
Y1 - 2011/12
N2 - Objectives: Baicalein, a flavonoid derived from the root of Scutelaria baicalensis Georgi, possesses antioxidative properties including reactive oxygen species scavenging and lipid peroxidation inhibiting activities. The present study was undertaken to investigate the neuroprotective effect of baicalein against dopamine (DA) neurotoxicity induced by exposure to a synthetic DA precursor, L-3,4-dihydroxyphenylalanine (L-DOPA), in cultured dopaminergic CATH.a cells. Methods and results: Exposure to L-DOPA for 24 hours reduced the number of viable cells and enhanced protein-bound quinone (quinoprotein) formation in the cell. Both effects were prevented by simultaneous treatment with baicalein. In addition, baicalein prevented the formation of DA semiquinone radicals from DA in an in vitro cell-free system. Long-term baicalein treatment for 96 hours also protected against excess LDOPA-induced cell death, and also increased glutathione (GSH) levels in CATH.a cells. Discussion: Our results indicate that baicalein has neuroprotective properties against excess L-DOPAinduced DA neurotoxicity through the suppression of DA quinone formation. Furthermore, the long-term treatment of baicalein upregulates intracellular GSH contents, which may also exert neuroprotective effects against oxidative stress-induced neuronal damage.
AB - Objectives: Baicalein, a flavonoid derived from the root of Scutelaria baicalensis Georgi, possesses antioxidative properties including reactive oxygen species scavenging and lipid peroxidation inhibiting activities. The present study was undertaken to investigate the neuroprotective effect of baicalein against dopamine (DA) neurotoxicity induced by exposure to a synthetic DA precursor, L-3,4-dihydroxyphenylalanine (L-DOPA), in cultured dopaminergic CATH.a cells. Methods and results: Exposure to L-DOPA for 24 hours reduced the number of viable cells and enhanced protein-bound quinone (quinoprotein) formation in the cell. Both effects were prevented by simultaneous treatment with baicalein. In addition, baicalein prevented the formation of DA semiquinone radicals from DA in an in vitro cell-free system. Long-term baicalein treatment for 96 hours also protected against excess LDOPA-induced cell death, and also increased glutathione (GSH) levels in CATH.a cells. Discussion: Our results indicate that baicalein has neuroprotective properties against excess L-DOPAinduced DA neurotoxicity through the suppression of DA quinone formation. Furthermore, the long-term treatment of baicalein upregulates intracellular GSH contents, which may also exert neuroprotective effects against oxidative stress-induced neuronal damage.
KW - Baicalein
KW - Dopamine quinone
KW - Dopamine-induced neurotoxicity
KW - Flavonoids
KW - L-DOPA
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U2 - 10.1179/1743132811Y.0000000032
DO - 10.1179/1743132811Y.0000000032
M3 - Article
C2 - 22196758
AN - SCOPUS:84555203792
VL - 33
SP - 1050
EP - 1056
JO - Neurological Research
JF - Neurological Research
SN - 0161-6412
IS - 10
ER -