Exp Mol Med.  2007 Jun;39(3):316-326.

Protective effects of fustin, a flavonoid from Rhus verniciflua tokes, on 6-hydroxydopamine-induced neuronal cell death

• Park BC
• Lee YS
• Park HJ
• Kwak MK
• Yoo BK
• Kim JY
• Kim JA

Abstract

6-Hydroxydopamine (6-OHDA) is a neurotoxin and is commonly used to generate experimental models of Parkinson's disease (PD). In this study, we investigated the signaling molecules involved in the 6-OHDA-induced cell death using a neuronal catecholaminergic cell line (SK-N-SH cells), and the protective effect of fustin, a flavonoid from Rhus verniciflua Stokes, on 6-OHDA-induced neuronal death. 6-OHDA significantly increased levels of reactive oxygen species (ROS), intracellular Ca2+ ([Ca2+](i)), and p38 phosphorylation. In addition, this ROS increase by 6-OHDA was reduced by pretreatment with N-acetylcysteine (NAC), a free radical scavenger, but not by bis-(o-aminophenoxy)-ethane-N,N,N,N-tetraacetic acid (BAPTA), a Ca2+ chelator. However, the [Ca2+](i) increase induced by 6-OHDA was suppressed by NAC. Moreover, pretreatment with NAC or BAPTA significantly prevented the 6-OHDA-induced increases in p38 phosphorylation, Bax/Bcl-2 ratio, and caspase-3 activity. Although 6-OHDA-increased phosphorylation of p38 was prevented by NAC or BAPTA, inhibition of p38 by SB203580 did not suppress ROS, Bax/Bcl-2 ratio, or caspase-3 activity increases, and only partially prevented 6-OHDA-induced cell death, thus demonstrating that p38 activation is a component of a signaling pathway leading to the initiation of 6-OHDA-induced cell death, which acts in parallel with an ROS-Ca2+ -Bcl-2-caspase-3 pathway. Moreover, fustin not only suppressed 6-OHDA-induced cell death in a concentration-dependent manner but also blocked 6-OHDA-induced increases in ROS, [Ca2+](i), Bax/Bcl-2 ratio, caspase-3 activity, and p38 phosphorylation. These results suggest that fustin exerts neuroprotection against 6-OHDA-induced cell death.

Keyword

calcium; caspase-3; cell death; oxidopamine; p38 mitogen-activated protein kinases; Parkinson disease; reactive oxygen species

MeSH Terms

Acetylcysteine/pharmacology
Apoptosis
Calcium/metabolism
Caspase 3/metabolism
Cell Death/drug effects
Cell Line, Tumor
Cytoprotection
Egtazic Acid/analogs & derivatives/pharmacology
Enzyme Activation
Flavonoids/*pharmacology
Humans
Imidazoles/pharmacology
Neurons/cytology/*drug effects
Oxidopamine/*toxicity
Phosphorylation
Proto-Oncogene Proteins c-bcl-2/metabolism
Pyridines/pharmacology
Reactive Oxygen Species/metabolism
Rhus/*chemistry
Signal Transduction
p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism