Background: Exposure to diazinon (DZN) as an organophosphorus insecticide is
associated with reducing the antioxidant capacity of cells. N-acetyl cysteine (NAC) is widely
used in clinics to treat several diseases related to oxidative stress.
Objective: The current study was aimed to evaluate the prophylactic and therapeutic roles of
NAC on biochemical and oxidative changes induced by acute poisoning of DZN in various
tissues of male Wistar rats.
Methods: Thirty rats were divided into five groups: control group received corn oil as DZN
solvent; DZN group received 100 mg/kg of DZN; NAC group received 160 mg/kg of NAC;
NAC-DZN and DZN-NAC groups received 160 mg/kg of NAC before and after 100 mg/kg
of DZN injection, respectively. Plasma and various tissues were prepared and evaluated for
the measurement of the biochemical parameters and oxidative stress biomarkers.
Results: Both prophylactic and therapeutic treatments by NAC ameliorated the increased
lipid peroxidation and decreased glutathione level and superoxide dismutase, catalase and
glutathione S-transferase activities in tissues (P<0.05). Moreover, treatment with the NAC
caused a significant reduction in DZN-induced high levels of plasma biochemical parameters.
Furthermore, acetylcholinesterase activity was positively correlated with both LDH
(P=0.000) activity and GSH (P=0.001) level and negatively correlated with MDA (P=0.009)
level in the brain.
Conclusion: Results suggest that NAC could effectively ameliorate the DZN-induced oxidative
stress and cholinergic hyperactivity in various tissues especially in the brain, through
free radicals scavenging and GSH synthesis. Prophylactic approach exerted a stronger protective
effect compared to a therapeutic treatment.