Research Article
CNB-001 a Novel Curcumin Derivative, Guards Dopamine
Neurons in MPTP Model of Parkinson’s Disease
Richard L. Jayaraj,
1
Namasivayam Elangovan,
1
Krishnan Manigandan,
1
Sonu Singh,
2
and Shubha Shukla
2
1
Department of Biotechnology, Periyar University, Salem, Tamilnadu 636011, India
2
Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh 226031, India
Correspondence should be addressed to Namasivayam Elangovan; elangovannn@gmail.com
Received 27 February 2014; Accepted 14 May 2014; Published 17 June 2014
Academic Editor: Arianna Scuteri
Copyright © 2014 Richard L. Jayaraj et al. Tis is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
Copious experimental and postmortem studies have shown that oxidative stress mediated degeneration of nigrostriatal
dopaminergic neurons underlies Parkinson’s disease (PD) pathology. CNB-001, a novel pyrazole derivative of curcumin, has recently
been reported to possess various neuroprotective properties. Tis study was designed to investigate the neuroprotective mechanism
of CNB-001 in a subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) rodent model of PD. Administration of MPTP
(30 mg/kg for four consecutive days) exacerbated oxidative stress and motor impairment and reduced tyrosine hydroxylase (TH),
dopamine transporter, and vesicular monoamine transporter 2 (VMAT2) expressions. Moreover, MPTP induced ultrastructural
changes such as distorted cristae and mitochondrial enlargement in substantia nigra and striatum region. Pretreatment with CNB-
001 (24 mg/kg) not only ameliorated behavioral anomalies but also synergistically enhanced monoamine transporter expressions
and cosseted mitochondria by virtue of its antioxidant action. Tese fndings support the neuroprotective property of CNB-001
which may have strong therapeutic potential for treatment of PD.
1. Introduction
Parkinson’s disease (PD), a progressive neurodegenerative
disorder, is characterized by degeneration of dopaminergic
(DA-ergic) neurons in substantia nigra pars compacta (SNpc)
and resultant loss of dopamine (DA) in the striatum (motor
loci). Clinical diagnosis reports have shown that cardinal
behavioral features of PD include rigidity, dyskinesia, gait
imbalance, and tremor at rest [1]. Tough the etiology of
PD remains obscure, various experimental studies have
reported the involvement of oxidative stress, mitochondria
dysfunction, apoptosis, and infammation either separately
or cooperatively to induce neurodegeneration [2]. DA, a
vital neurotransmitter (important for motor coordination),
is synthesized in nigrostriatal pathway and undergoes
autooxidation to form toxic reactive oxygen species (ROS)
and quinone molecules which in turn initiates pathological
response [3]. Apart from DA depletion, a profound reduction
in specifc neurochemical markers such as tyrosine
hydrolase (TH), DA transporter (DAT), and vesicular
monoamine transporter 2 (VMAT2) has been reported
in PD [4, 5]. In idiopathic PD, mitochondrial complex I
impairment leading to free radical generation which evokes
respiratory chain defcits is very well documented [6]. Hence,
various mitochondrial complex I inhibitors such as MPTP
(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), rotenone,
isoquinoline, paraquat, and 6-OHDA (6-hydroxydopamine)
are used to create PD models to get insights into precise
mechanisms underlying neurodegeneration in PD [7].
MPTP, a catecholamine neurotoxin, selectively degenerates
dopaminergic neurons via monoamine oxidase-B- (MAO-B-
) mediated conversion of MPTP to its toxic/active metabolite
MPP
+
. Further MPP
+
is taken into dopaminergic neurons
via DA transporter and sequestered in mitochondria and
inhibits complex I of electron transport chain resulting in
enhanced ROS formation and decreased ATP production.
Moreover, MPP
+
is also taken into the cytosol through
vesicular monoamine transporter 2 (VMAT2) and supports
lethality [8]. Hence, assessment of DAT and VMAT2
reveals a greater picture regarding DA integrity and
Hindawi Publishing Corporation
BioMed Research International
Volume 2014, Article ID 236182, 11 pages
http://dx.doi.org/10.1155/2014/236182