Research Article Open Access
Saraswathy et al., J Mol Biomark Diagn 2014, 6:4
DOI: 10.4172/2155-9929.1000241
Volume 6 • Issue 4 • 1000241
J Mol Biomark Diagn
ISSN:2155-9929 JMBD an open access journal
*Corresponding author: Dr. Saraswathy G.R., Department of Pharmacology,
M.S. Ramaiah University of Applied Sciences, Bangalore, Karnataka, India, Tel:
08123230400; Fax: 080-23607488; E-mail: saraswathypradish@gmail.com
Received July 08, 2015; Accepted July 28, 2015; Published July 31, 2015
Citation: Saraswathy GR, Maheswari E, Santhrani T (2015) Protective Effect of
Alpha Lipoic Acid against Phenytoin Induced Behavioral Abnormalities in Rats. J
Mol Biomark Diagn 5: 241. doi:10.4172/2155-9929.1000241
Copyright: © 2015 Saraswathy GR, et al. This is an open-access article
distributed under the terms of the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium, provided
the original author and source are credited
Keywords: Phenytoin; Alpha lipoic acid; Oxidative stress; Behavioral
abnormalities
Introduction
Epileptic disorders afect approximately 0.5-1% of human
population [1]. Te main goal in the treatment of epilepsy is to attain
a complete control over seizures without potential side efects to
improve the quality of life. Phenytoin is a most common and efective
antiepileptic drug (AED) prescribed for a prolonged period to achieve
seizure control in all types of generalized as well as partial seizures
and status epilepticus [2]. Phenytoin causes several serious side efects
notably neurotoxicity [3]. Tis drug generates reactive oxygen species
during its metabolism leading to severe oxidative stress which in turn
results in neuro-degeneration. Long term phenytoin therapy causes
cerebellar degeneration [4] resulting in cognitive impairment [5],
ataxia, nystagmus and slurred speech [6].
Alpha-lipoic acid (ALA) also known as thioctic acid (TA), is
essential for the function of diferent enzymes of oxidative metabolism
[7,8]. ALA was initially used in the treatment of acute poisoning with
amanita phalloides, deadly poison followed by its application in treating
neuropathic complaints [9]. It is believed that ALA or its reduced form,
dihydrolipoic acid (DHLA) possess a number of biochemical functions
acting as biological antioxidants, as metal chelators, reducing the
oxidized forms of other antioxidant agents such as vitamin C and E
and glutathione (GSH). ALA has also shown to improve endothelial
dysfunction [10] and to reduce oxidative stress post exercise training
[11]. It also protects against the development of atherosclerosis and
inhibits the progression of an already established atherosclerosis
plaque [12,13]. Tese above-mentioned benefts have insisted the use
of ALA as a potential therapeutic agent for many chronic diseases with
great epidemiological as well as economic and social impact such as
diabetes mellitus (DM) and its complications [14,15], hypertension
[16], Alzheimer’s disease (AD) [17], Down syndrome [18], cognitive
dysfunction and some types of cancer [19]. ALA is recommended as a
dietary supplement in medical and nutritional management of patients.
Te therapeutic or toxic efects of phenytoin depend on its serum
concentration. Te serum levels of phenytoin were estimated at the
end of the study period afer the steady state of the drug was achieved
to investigate if there were any pharmacokinetic interactions between
phenytoin and ALA. Pharmacodynamic interference of ALA over
antiepileptic protection ofered by phenytoin was also studied.
Our work is a preliminary study to assess the ameliorative efect of
ALA against phenytoin induced behavioral abnormalities. Phenytoin
and its metabolites are reported to induce oxidative stress in brain
regions leading to behavioral abnormalities. Hence, we explored the
ameliorative efect of ALA against phenytoin induced behavioral
abnormalities like impaired cognition, exploratory behavior,
spontaneous motor activity and locomotor activity in addition to the
estimation of regional brain lipid peroxidation and acetyl cholinesterase
Protective Effect of Alpha Lipoic Acid against Phenytoin Induced
Behavioral Abnormalities in Rats
Saraswathy GR
1
*, Maheswari E
2
and Santhrani T
3
1
Department of Pharmacology, M.S. Ramaiah University of Applied Sciences, Karnataka, India
2
Department of Pharmacy Practice, M.S. Ramaiah University of Applied Sciences, Karnataka, India
3
Department of Pharmacology, Institute of Pharmaceutical Technology, Sri Padmavathi Mahila Visvavidyalayam, Andhra Pradesh, India
Abstract
Background: Long term administration of antiepileptic drug phenytoin is reported to cause behavioral
abnormalities mediated via oxidative stress. The effect of an antioxidant alpha lipoic acid (ALA) against phenytoin
induced behavioral abnormalities was investigated.
Methods: The study was carried out in albino wistar rats. The rats were divided into fve groups of six animals
each. Group 1 received 0.2% carboxy methyl cellulose (CMC, p.o), group 2 received 20 mg/kg phenytoin (p.o),
groups 3,4 and 5 received 50, 100 and 200 mg/kg (p.o) of ALA in 0.2% CMC, respectively 1 h prior to phenytoin for
45 days. Motor coordination, exploratory behavior, memory and spontaneous motor activity were evaluated by Rota
rod, Hole board, Elevated plus maze and Actophotometer respectively. On day 45, regional brain lipid peroxidation
and acetylcholinesterase (ACh E) activity along with brain histopathological investigation were performed after
euthanasia. In addition, pharmacokinetic and pharmacodynamic drug interactions between phenytoin and ALA were
also studied. Results: Long term administration of phenytoin showed behavioral abnormalities, increased regional
brain malondialdehyde (MDA) and ACh E activity. The histopathological investigation showed congested and
damaged cells in brain regions. ALA substantially reversed phenytoin induced behavioral abnormalities, oxidative
stress and alleviated the histopathological abnormalities. There were no signifcant differences in the serum levels of
phenytoin and the degree of protection offered by phenytoin in ALA supplemented groups revealing that there were
no pharmacokinetic and pharmacodynamic interactions between phenytoin and ALA.
Conclusion: This study reports the effectiveness of ALA against phenytoin induced behavioral abnormalities
and oxidative stress in rats without altering the bioavailability of phenytoin and its therapeutic effect.
Journal of Molecular Biomarkers
& Diagnosis
J
o
u
r
n
a
l
o
f
M
o
l
e
c
u
l
a
r
B
i
o
m
a
r
k
e
r
s
&
D
i
a
g
n
o
s
i
s
ISSN: 2155-9929