Abstract
Objectives: Organophosphate (OP) pesticides inhibit both red blood cell (RBC) and plasma cholinesterases (ChEs). Oximes, especially pralidoxime (2-PAM), are widely used as antidotes to treat OP poisoning. In addition, N-acetylcysteine (NAC) is sometimes used as an adjuvant antidote. The current study aimed to assess the feasibility of using NAC as a single therapeutic agent for OP poisoning in comparison to in vitro 2-PAM. Methods:This study was carried out at the Razi Drug Research Center of Iran University of Medical Sciences, Tehran, Iran, between April and September 2014. A total of 22 healthy human subjects were recruited and 8 mL citrated blood samples were drawn from each subject. Dichlorvos-inhibited blood samples were separately exposed to low and high doses (final concentrations of 300 and 600 μmol.L-1, respectively) of 2-PAM, NAC and cysteine. Plasma and RBCs were then separated by centrifugation and their ChE activity was measured using spectrophotometry. Results: Although cysteine—and not NAC—increased the ChE activity of both plasma and RBCs over those of dichlorvos, it did not increase them over those of a high dose of 2-PAM. Conclusion:These results suggest that the direct reactions of 2-PAM and cysteine with dichlorvos and the reactivation of phosphorylated ChEs occurr via an associative stepwise addition-elimination process. High therapeutic blood concentrations of cysteine are needed for the elevation of ChE activity in plasma and RBCs; however, both this agent and NAC may still be effective in the reactivation of plasma and RBC ChEs.
Publication details
- DOI
- 10.18295/squmj.2017.17.03.006
- Journal
- Sultan Qaboos University Medical Journal, 17(3), 293-300
- Publisher
- Sultan Qaboos University
- Open access
- Gold open access
- License
- CC BY-ND 4.0
Cite this article
APA 7
Mohammadi, H., Jalilian, J., Shetab-Boushehri, M. Y., & V., S. (2025). In Vitro Cysteine Reactivates Organophosphate Insecticide Dichlorvos-Inhibited Human Cholinesterases. Sultan Qaboos University Medical Journal, 17(3), 293-300. https://doi.org/10.18295/squmj.2017.17.03.006
MLA 9
Mohammadi, Hamidreza, et al. "In Vitro Cysteine Reactivates Organophosphate Insecticide Dichlorvos-Inhibited Human Cholinesterases." Sultan Qaboos University Medical Journal, vol. 17, no. 3, 2025, pp. 293-300. https://doi.org/10.18295/squmj.2017.17.03.006.
Chicago (author–date)
Mohammadi, Hamidreza, Jafar Jalilian, Mohammad Y. Shetab-Boushehri, and Seyed V. 2025. "In Vitro Cysteine Reactivates Organophosphate Insecticide Dichlorvos-Inhibited Human Cholinesterases." Sultan Qaboos University Medical Journal 17 (3): 293-300. https://doi.org/10.18295/squmj.2017.17.03.006.
Harvard
Mohammadi, H., Jalilian, J., Shetab-Boushehri, M. Y. and V., S. (2025) 'In Vitro Cysteine Reactivates Organophosphate Insecticide Dichlorvos-Inhibited Human Cholinesterases', Sultan Qaboos University Medical Journal, 17(3), pp. 293-300. doi:10.18295/squmj.2017.17.03.006.
Vancouver
Mohammadi H, Jalilian J, Shetab-Boushehri MY, V. S. In Vitro Cysteine Reactivates Organophosphate Insecticide Dichlorvos-Inhibited Human Cholinesterases. Sultan Qaboos University Medical Journal. 2025;17(3):293-300. doi:10.18295/squmj.2017.17.03.006
IEEE
H. Mohammadi, J. Jalilian, M. Y. Shetab-Boushehri, and S. V., "In Vitro Cysteine Reactivates Organophosphate Insecticide Dichlorvos-Inhibited Human Cholinesterases," Sultan Qaboos University Medical Journal, vol. 17, no. 3, pp. 293-300, 2025, doi: 10.18295/squmj.2017.17.03.006.