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Effect of several new and currently available oxime cholinesterase reactivators on tabun-intoxicated rats

Jana Zdarova Karasova1, Jiri Kassa1, Young-Sik Jung2

  • 1Department of Toxicology, Faculty of Military Health Sciences, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic.

International Journal of Molecular Sciences
|March 31, 2009
PubMed

Insights

Eleven oxime reactivators were tested against tabun poisoning in rats. Trimedoxime and new compound K127 showed the best efficacy in reactivating acetylcholinesterase and butyrylcholinesterase enzymes.

Area of Science:

  • Toxicology
  • Pharmacology
  • Neuroscience

Background:

  • Organophosphate poisoning, like that from tabun, inhibits acetylcholinesterase (AChE) and butyrylcholinesterase (BChE).
  • Oxime reactivators are crucial antidotes for organophosphate intoxication.
  • Evaluating novel oximes alongside existing ones is vital for improving treatment efficacy.

Purpose of the Study:

  • To compare the in vivo therapeutic efficacies of eleven oxime-based acetylcholinesterase reactivators.
  • To assess the effectiveness of these oximes in treating tabun intoxication in a rat model.
  • To identify superior reactivators for potential clinical use.

Main Methods:

  • An in vivo study using a rat model was conducted.
  • Eleven oxime compounds, including known drugs (obidoxime, trimedoxime, HI-6) and novel syntheses, were administered.
  • Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) reactivation in blood, plasma, and brain were measured.

Main Results:

  • Trimedoxime (16%) and K127 (25%) demonstrated the highest AChE reactivation in blood among existing oximes.
  • Trimedoxime, K117, and K127 showed the best plasma BChE reactivation (approx. 30%).
  • Trimedoxime and obidoxime provided partial protection of brain AChE (20% and 12%) and BChE (30% and 16%) against tabun.

Conclusions:

  • Novel oxime K127 exhibits promising acetylcholinesterase and butyrylcholinesterase reactivation potential.
  • Trimedoxime remains an effective option, showing good reactivation and partial neuroprotection.
  • Further research into K127 and similar novel oximes is warranted for tabun poisoning treatment.
Keywords:
Acetylcholinesterasebutyrylcholinesteraseoximespretreatmentreactivators

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