Biology Reference
In-Depth Information
Chapter 20
Comparative Evaluation of the Effects
of Taurine and Thiotaurine on Alterations
of the Cellular Redox Status and Activities
of Antioxidant and Glutathione-Related
Enzymes by Acetaminophen in the Rat
Miteshkumar Acharya and Cesar A. Lau-Cam
Abstract
The present study was carried out to ascertain the impact of replacing the
sulfonate group of TAU with thiosulfonate, as present in thiotaurine (TTAU), on the
protective actions of TAU against hepatocellular damage and biochemical altera-
tions related to oxidative stress and glutathione redox cycling, synthesis, and utiliza-
tion caused by a high dose of acetaminophen (APAP). To this end, male
Sprague-Dawley rats, 225-250 g, were intraperitoneally treated with a 2.4 mmol/kg
dose of TAU (or TTAU), followed 30 min later by 800 mg/kg of APAP. A reference
group received 2.4 mmol/kg of
N
-acetylcysteine (NAC) prior to APAP. Naive rats
served as controls. The animals were sacrificed 6 h after receiving APAP and their
blood and livers were collected. Plasma and liver homogenates were analyzed for
indices of cell damage (plasma transaminases, plasma lactate dehydrogenase),
oxidative stress (malondialdehyde = MDA, reduced glutathione = GSH, glutathione
disulfide = GSSG, catalase, glutathione peroxidase, superoxide dismutase), glutathi-
one cycling (glutathione reductase), utilization (glutathione S-transferase), and syn-
thesis (
-glutamylcysteine synthetase) activities. APAP increased MDA formation
and lowered the GSH/GSSG ratio and all enzyme activities, especially those of
antioxidant enzymes. In general, TTAU was equipotent with NAC and more potent
than TAU in protecting the liver. Taken into account the results of a previous study
comparing the actions of TAU and hypotaurine (HTAU), the sulfinate analog of
TAU, it appears that the sulfinate and thiosulfonate analogs are somewhat more
effective than the parent sulfonate TAU in counteracting APAP-induced hepatic
alterations in the liver and plasma.
γ
M. Acharya C. A. Lau-Cam (
*
)
Department of Pharmaceutical Sciences, College of Pharmacy
and Allied Health Professions, St. John's University,
Jamaica , NY 11439 , USA
e-mail: claucam@usa.net
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