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Combined Pre- and Posttreatment of Paraoxon Exposure. Molecules 2020; 25:molecules25071521. [PMID: 32230733 PMCID: PMC7180863 DOI: 10.3390/molecules25071521] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/19/2020] [Accepted: 03/25/2020] [Indexed: 02/01/2023] Open
Abstract
AIMS Organophosphates (OPCs), useful agents as pesticides, also represent a serious health hazard. Standard therapy with atropine and established oxime-type enzyme reactivators is unsatisfactory. Experimental data indicate that superior therapeutic results can be obtained when reversible cholinesterase inhibitors are administered before OPC exposure. Comparing the protective efficacy of five such cholinesterase inhibitors (physostigmine, pyridostigmine, ranitidine, tacrine, or K-27), we observed best protection for the experimental oxime K-27. The present study was undertaken in order to determine if additional administration of K-27 immediately after OPC (paraoxon) exposure can improve the outcome. METHODS Therapeutic efficacy was assessed in rats by determining the relative risk of death (RR) by Cox survival analysis over a period of 48 h. Animals that received only pretreatment and paraoxon were compared with those that had received pretreatment and paraoxon followed by K-27 immediately after paraoxon exposure. RESULTS Best protection from paraoxon-induced mortality was observed after pretreatment with physostigmine (RR = 0.30) and K-27 (RR = 0.34). Both substances were significantly more efficacious than tacrine (RR = 0.67), ranitidine (RR = 0.72), and pyridostigmine (RR = 0.76), which were less efficacious but still significantly reduced the RR compared to the no-treatment group (paraoxon only). Additional administration of K-27 immediately after paraoxon exposure (posttreatment) did not further reduce mortality. Statistical analysis between pretreatment before paraoxon exposure alone and pretreatment plus K-27 posttreatment did not show any significant difference for any of the pretreatment regimens. CONCLUSIONS Best outcome is achieved if physostigmine or K-27 are administered prophylactically before exposure to sublethal paraoxon dosages. Therapeutic outcome is not further improved by additional oxime therapy immediately thereafter.
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Lorke DE, Nurulain SM, Hasan MY, Kuča K, Petroianu GA. Oximes as pretreatment before acute exposure to paraoxon. J Appl Toxicol 2019; 39:1506-1515. [PMID: 31264735 DOI: 10.1002/jat.3835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 11/11/2022]
Abstract
Organophosphates, useful agents as pesticides, also represent a serious danger due to their high acute toxicity. There is indication that oximes, when administered before organophosphate exposure, can protect from these toxic effects. We have tested at equitoxic dosage (25% of LD01 ) the prophylactic efficacy of five experimental (K-48, K-53, K-74, K-75, K-203) and two established oximes (pralidoxime and obidoxime) to protect from mortality induced by the organophosphate paraoxon. Mortalities were quantified by Cox analysis and compared with those observed after pretreatment with a strong acetylcholinesterase inhibitor (10-methylacridine) and after the FDA-approved pretreatment compound pyridostigmine. All nine tested substances statistically significantly reduced paraoxon-induced mortality. Best protection was conferred by the experimental oxime K-48, reducing the relative risk of death (RR) to 0.10, which was statistically significantly superior to pyridostigmine (RR = 0.31). The other oximes reduced the RR to 0.13 (obidoxime), 0.20 (K-203), 0.21 (K-74), 0.24 (K-75) and 0.26 (pralidoxime), which were significantly more efficacious than 10-methylacridine (RR = 0.65). These data support the hypothesis that protective efficacy is not primarily due to cholinesterase inhibition and indicate that the tested experimental oximes may be considered promising alternatives to the established pretreatment compound pyridostigmine.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, University Park GL 495 D, Florida International University, Miami, Florida.,College of Medicine and Health Sciences, Department of Anatomy and Cellular Biology, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Syed M Nurulain
- Department of Bio Science, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Mohamed Y Hasan
- Department of Pharmacology & Therapeutics, College of Medicine and Health Sciences, UAE University, United Arab Emirates
| | - Kamil Kuča
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Georg A Petroianu
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, University Park GL 495 D, Florida International University, Miami, Florida
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Abstract
Standard therapy of Organophosphorus Compound (OPC) poisoning with
oxime-type acetylcholinesterase (AChE) reactivators is unsatisfactory. New bispyridinium
oximes have therefore been synthesized. This review summarizes in vitro characteristics
of established (pralidoxime, obidoxime, trimedoxime, HI-6) and experimental (K-)oximes,
and compares their protective efficacy in vivo, when administered shortly after exposure
to Diisopropylfluorophosphate (DFP) and three OPC pesticides (ethyl-paraoxon, methylparaoxon,
azinphos-methyl) in the same experimental setting.
In addition to reactivating cholinesterase, oximes also inhibit this enzyme; strongest
AChE inhibition (IC50 rat blood: 1-9 µM) is observed in vitro for the oximes with a xylene
linker (K-107, K-108, K-113). AChE inhibition is weakest for K-27, K-48 and HI-6 (IC50
>500 µM). Intrinsic AChE inhibition of oximes in vitro (IC50, rat) is strongly correlated with their LD50 (rat):
oximes with a high IC50 (K-27, K-48, pralidoxime, obidoxime) also show a high LD50, making them relatively
non-toxic, whereas oximes K-107, K-108 and K-113 (low IC50 and LD50) are far more toxic.
When given in vivo after OP exposure, best protection is conferred by K-27, reducing the relative risk of death
to 16-58% of controls, which is significantly superior to pralidoxime in DFP-, ethyl-paraoxon- and methylparaoxon-
exposure, and to obidoxime in ethyl-paraoxon- and methyl-paraoxon-exposure. Marked reduction in
mortality is also achieved by K-48, K-53, K-74 and K-75, whereas K-107, K-108 and K-113 have no or only a
very weak mortality-reducing effect. K-27 is the most promising K-oxime due to its strong reactivation potency,
weak cholinesterase inhibition and high LD50, allowing administration in large, very efficacious dosages.
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Affiliation(s)
- Dietrich E. Lorke
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, University Park GL 495 D, 11200 SW 8th St, Miami 33199, Florida , United States
| | - Georg A. Petroianu
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, University Park GL 495 D, 11200 SW 8th St, Miami 33199, Florida , United States
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Lorke DE, Petroianu GA. The Experimental Oxime K027-A Promising Protector From Organophosphate Pesticide Poisoning. A Review Comparing K027, K048, Pralidoxime, and Obidoxime. Front Neurosci 2019; 13:427. [PMID: 31191210 PMCID: PMC6547910 DOI: 10.3389/fnins.2019.00427] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/15/2019] [Indexed: 11/13/2022] Open
Abstract
Poisoning with organophosphorus compounds (OPCs) is a major problem worldwide. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. In search of more efficacious broad-spectrum oximes, new bispyridinium (K-) oximes have been synthesized, with K027 being among the most promising. This review summarizes pharmacokinetic characteristics of K027, its toxicity and in vivo efficacy to protect from OPC toxicity and compares this oxime with another experimental bisquaternary asymmetric pyridinium aldoxime (K048) and two established oximes (pralidoxime, obidoxime). After intramuscular (i.m.) injection, K027 reaches maximum plasma concentration within ∼30 min; only ∼2% enter the brain. Its intrinsic cholinesterase inhibitory activity is low, making it relatively non-toxic. In vitro reactivation potency is high for ethyl-paraoxon-, methyl-paraoxon-, dichlorvos-, diisopropylfluorophosphate (DFP)- and tabun-inhibited cholinesterase. When administered in vivo after exposure to the same OPCs, K027 is comparable or more efficacious than pralidoxime and obidoxime. When given as a pretreatment before exposure to ethyl-paraoxon, methyl-paraoxon, DFP, or azinphos-methyl, it is superior to the Food and Drug Administration-approved compound pyridostigmine and comparable to physostigmine, which because of its entry into the brain may cause unwanted behavioral effects. Because of its low toxicity, K027 can be given in high dosages, making it a very efficacious oxime not only for postexposure treatment but also for prophylactic administration, especially when brain penetration is undesirable.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States.,Department of Anatomy and Cellular Biology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Georg A Petroianu
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
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Lorke DE, Petroianu GA. Reversible cholinesterase inhibitors as pretreatment for exposure to organophosphates. A review. J Appl Toxicol 2018; 39:101-116. [PMID: 30027640 DOI: 10.1002/jat.3662] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/06/2018] [Indexed: 01/04/2023]
Abstract
Organophosphorus compounds (OPCs), inhibitors of acetylcholinesterase (AChE), are useful agents as pesticides, but also represent a serious health hazard. Standard therapy with atropine and established oxime-type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. Better therapeutic results are obtained, when reversible AChE inhibitors are administered before OPC exposure. This review summarizes the history of such a pretreatment approach and sums up a set of experiments undertaken in search of compounds that are efficacious when given before a broad range of OPCs. The prophylactic efficacy of 10 known AChE inhibitors, either already used clinically for different indications (physostigmine, pyridostigmine, ranitidine, tiapride, tacrine, amiloride, metoclopramide, methylene blue) or developed for possible therapeutic use in the future (7-methoxytacrine, K-27) was compared, when administered before exposure to six chemically diverse OPCs in the same experimental setting: ethyl-paraoxon, methyl-paraoxon, diisopropylfluorophosphate, terbufos sulfone, azinphos-methyl and dicrotophos. The experimental oxime K-27 was the most efficacious compound, affording best protection, when administered before terbufos sulfone, azinphos-methyl and dicrotophos, second best before ethyl- and methyl-paraoxon exposure and third best before diisopropylfluorophosphate administration. This ranking was similar to that of physostigmine, which was superior to the Food and Drug Administration-approved pretreatment for soman with pyridostigmine. Tiapride, amiloride, metoclopramide, methylene blue and 7-methoxytacrine did not achieve protection. No correlation was observed between the IC50 of the reversible AChE inhibitors and their protective efficacy. These studies indicate that K-27 can be considered a very promising broad-spectrum prophylactic agent in case of imminent organophosphate exposure, which may be related to its AChE reactivating activity rather than its AChE inhibition.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Georg A Petroianu
- Department of Cellular Biology & Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
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Kassa J, Misik J, Hatlapatkova J, Zdarova Karasova J. A comparison of neuroprotective efficacy of two novel reactivators of acetylcholinesterase called K920 and K923 with the oxime K203 and trimedoxime in tabun-poisoned rats. Toxicol Mech Methods 2017; 27:236-243. [DOI: 10.1080/15376516.2016.1275907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Jiri Kassa
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
| | - Jan Misik
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
| | - Jana Hatlapatkova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
| | - Jana Zdarova Karasova
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czech Republic
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Kuca K, Korabecny J, Dolezal R, Nepovimova E, Soukup O, Gorecki L, Musilek K. Tetroxime: reactivation potency – in vitro and in silico study. RSC Adv 2017. [DOI: 10.1039/c6ra16499d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tetroxime – a unique bisquaternary compound with four oxime groups.
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Affiliation(s)
- K. Kuca
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Chemistry
- Faculty of Science
| | - J. Korabecny
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Toxicology and Military Pharmacy
- Faculty of Military Health Sciences
| | - R. Dolezal
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
| | - E. Nepovimova
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Toxicology and Military Pharmacy
- Faculty of Military Health Sciences
| | - O. Soukup
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
| | - L. Gorecki
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Toxicology and Military Pharmacy
- Faculty of Military Health Sciences
| | - K. Musilek
- Biomedical Research Center
- University Hospital Hradec Kralove
- Czech Republic
- Department of Chemistry
- Faculty of Science
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Kassa J, Sepsova V, Horova A, Musilek K. A comparison of the reactivating and therapeutic efficacy of two novel bispyridinium oximes (K920, K923) with the oxime K203 and trimedoxime in tabun-poisoned rats and mice. J Appl Biomed 2015. [DOI: 10.1016/j.jab.2015.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Kassa J, Karasová JZ, Pavlíková R, Caisberger F, Bajgar J. The Ability of Oxime Mixtures to Increase the Reactivating and Therapeutic Efficacy of Antidotal Treatment of Cyclosarin Poisoning in Rats and Mice. ACTA MEDICA (HRADEC KRÁLOVÉ) 2015; 55:27-31. [DOI: 10.14712/18059694.2015.71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The reactivating and therapeutic efficacy of two combinations of oximes (HI‑6 + trimedoxime and HI‑6 + K203) was compared with the effectiveness of antidotal treatment involving single oxime (HI‑6, trimedoxime, K203) using in vivo methods. In vivo determined percentage of reactivation of cyclosarin‑inhibited blood and tissue acetylcholinesterase in poisoned rats showed that the reactivating efficacy of both combinations of oximes is slightly higher than the reactivating efficacy of the most effective individual oxime in blood, diaphragm as well as in brain. Moreover, both combinations of oximes were found to be slightly more efficacious in the reduction of acute lethal toxic effects in cyclosarin‑poisoned mice than the antidotal treatment involving single oxime. Based on the obtained data, we can conclude that the antidotal treatment involving chosen combinations of oximes brings a beneficial effect for its ability to counteract the acute poisoning with cyclosarin.
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Nurulain SM, Ojha S, Tekes K, Shafiullah M, Kalasz H, Adem A. Efficacy of N-Acetylcysteine, Glutathione, and Ascorbic Acid in Acute Toxicity of Paraoxon to Wistar Rats: Survival Study. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:329306. [PMID: 26167240 PMCID: PMC4488549 DOI: 10.1155/2015/329306] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/16/2015] [Indexed: 12/31/2022]
Abstract
There are a great number of reports with assertions that oxidative stress is produced by organophosphorus compound (OPC) poisoning and is a cofactor of mortality and morbidity in OPC toxicity. In addition, antioxidants have been suggested as adjuncts to standard therapy. However, there is no substantial evidence for the benefit of the use of antioxidants in survival after acute intoxication of OPCs. The present study was conducted to assess the effectiveness of three non-enzymatic antioxidants (NEAOs), N-acetylcysteine (NAC), glutathione (GSH), and ascorbic acid (AA), in acute intoxication of adult male Wister rats with paraoxon. The efficacy of the antioxidants was estimated as both a pretreatment and a concurrent application along with the standard oxime, pralidoxime (2-PAM). Relative risk of death after 48 hours of application was estimated by Cox regression analysis. The results revealed no benefit of either tested NEAO to the improvement in survival of experimental rats. The application of these antioxidants was found to be deleterious when administered along with pralidoxime compared to the treatment with pralidoxime alone. It has been concluded that the tested non-enzymatic antioxidants are not useful in acute toxicity for improving survival rates. However, the individual toxic dynamics of diversified OPCs should not be overlooked and further studies with different OPCs are suggested.
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Affiliation(s)
- Syed M. Nurulain
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
| | - Shreesh Ojha
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
| | - Kornelia Tekes
- Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary
| | - Mohammad Shafiullah
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
| | - Huba Kalasz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary
| | - Abdu Adem
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
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Kassa J, Hatlapatková J, Žďárová Karasová J. The Evaluation of the Potency of Newly Developed Oximes (K727, K733) and Trimedoxime to Counteract Acute Neurotoxic Effects of Tabun in Rats. ACTA MEDICA (HRADEC KRÁLOVÉ) 2015; 58:135-43. [PMID: 26960827 DOI: 10.14712/18059694.2016.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AIM The ability of two newly developed oximes (K727, K733) to reduce tabun-induced acute neurotoxic signs and symptoms was evaluated and compared with currently available trimedoxime in rats. METHODS The neuroprotective effects of the oximes studied combined with atropine on Wistar rats poisoned with tabun at a lethal dose (380 µg/kg i.m.; 90% of LD50 value) were evaluated. Tabun-induced neurotoxicity was monitored by the functional observational battery consisting of 38 measurements of sensory, motor and autonomic nervous functions at 2 hours following tabun challenge. RESULTS All tested oximes combined with atropine enable tabun-poisoned rats to survive till the end of experiment. Both newly developed oximes (K727, K733) combined with atropine were able to decrease tabun-induced neurotoxicity in the case of lethal poisoning although they did not eliminate all tabun-induced acute neurotoxic signs and symptoms. CONCLUSION The ability of both novel bispyridinium oximes to decrease tabun-induced acute neurotoxicity was slightly lower than that of trimedoxime. Therefore, the newly developed oximes are not suitable for the replacement of commonly used oximes such as trimedoxime in the treatment of acute tabun poisonings.
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Affiliation(s)
- Jiří Kassa
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic.
| | - Jana Hatlapatková
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic
| | - Jana Žďárová Karasová
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defense, Hradec Králové, Czech Republic
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Kassa J, Sepsova V, Tumova M, Horova A, Musilek K. A Comparison of the Reactivating and Therapeutic Efficacy of Two Newly Developed Oximes (K727 and K733) with Oxime K203 and Trimedoxime in Tabun-Poisoned Rats and Mice. Basic Clin Pharmacol Toxicol 2014; 116:367-71. [DOI: 10.1111/bcpt.12327] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/08/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Jiri Kassa
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Vendula Sepsova
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Martina Tumova
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Anna Horova
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
| | - Kamil Musilek
- Department of Toxicology and Military Pharmacy; Faculty of Military Health Sciences; Hradec Kralove Czech Republic
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Kalász H, Nurulain SM, Veress G, Antus S, Darvas F, Adeghate E, Adem A, Hashemi F, Tekes K. Mini review on blood-brain barrier penetration of pyridinium aldoximes. J Appl Toxicol 2014; 35:116-23. [PMID: 25291712 DOI: 10.1002/jat.3048] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/14/2014] [Accepted: 06/16/2014] [Indexed: 01/27/2023]
Abstract
This paper reviews the blood-brain barrier (BBB) penetration of newly developed pyridinium aldoximes. Pyridinium aldoximes are highly charged hydrophilic compounds used in the treatment of subjects exposed to organophosphonates because they are effective as acetylcholinesterase reactivators. Pyridinium aldoximes have antidotal effects against poisoning with cholinesterase inhibitors, a frequent problem affecting people working with organophosphate-based insecticides and pesticides. Toxic organophosphonate products such as sarin and tabun can be used by terrorists as chemical warfare agents. This poses a severe challenge to all innocent and peace-loving people worldwide. This review gives a brief summary of BBB transporters and description of the current in vitro and in vivo methods for the characterization of BBB penetration of established and novel pyridinium aldoximes. The authors provide a putative mechanism of penetration, outline some future ways of formulation and discuss the possible advantages and disadvantages of increasing BBB penetration.
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Affiliation(s)
- H Kalász
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089, Budapest, Nagyvárad tér 4, Hungary; Department of Pharmacology and Therapeutics, CMHS, United Arab Emirates University, Al Ain, P.O.Box 17666, United Arab Emirates
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Petroianu GA, Athauda G, Darvas F, Kalasz H, Lorke DE. K-OXIME (K-27): PHOSPHYLATION-INDUCED CHANGES IN LOGP. ACTA ACUST UNITED AC 2014. [DOI: 10.31482/mmsl.2014.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Janockova J, Gulasova Z, Plsikova J, Musilek K, Kuca K, Mikes J, Culka L, Fedorocko P, Kozurkova M. Interaction of cholinesterase modulators with DNA and their cytotoxic activity. Int J Biol Macromol 2013; 64:53-62. [PMID: 24296409 DOI: 10.1016/j.ijbiomac.2013.11.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 11/22/2013] [Accepted: 11/25/2013] [Indexed: 11/16/2022]
Abstract
This research was focused on a study of the binding properties of a series of cholinesterase reactivators compounds K075 (1), K027 (2) and inhibitors compounds K524, K009 and 7-MEOTA (3-5) with calf thymus DNA. The nature of the interactions between compounds 1-5 and DNA were studied using spectroscopic techniques (UV-vis, fluorescence spectroscopy and circular dichroism). The binding constants for complexes of cholinesterase modulators with DNA were determined from UV-vis spectroscopic titrations (K=0.5 × 10(4)-8.9 × 10(5)M(-1)). The ability of the prepared analogues to relax topoisomerase I was studied with electrophoretic techniques and it was proved that ligands 4 and 5 inhibited this enzyme at a concentration of 30 μM. The biological activity of the novel compounds was assessed through an examination of changes in cell cycle distribution, mitochondrial membrane potential and cellular viability. Inhibitors 3-5 exhibited a cytotoxic effect on HL-60 (human acute promyelocytic leukaemia) cell culture, demonstrated a tendency to affect mitochondrial physiology and viability, and also forced cells to accumulate in the G1/G0-phase of the cell cycle. The cholinesterase reactivators 1 and 2 were found relatively save from the point of view of DNA binding, whereas cholinesterase inhibitors 3-5 resulted as strong DNA binding agents that limit their plausible use.
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Affiliation(s)
- Jana Janockova
- Institute of Chemistry, Department of Biochemistry, P. J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
| | - Zuzana Gulasova
- Institute of Chemistry, Department of Biochemistry, P. J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
| | - Jana Plsikova
- Institute of Chemistry, Department of Biochemistry, P. J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
| | - Kamil Musilek
- University of Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 50003 Hradec Kralove, Czech Republic
| | - Kamil Kuca
- University Hospital, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jaromir Mikes
- Institute of Biology and Ecology, Department of Cellular Biology, P. J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
| | - Lubomir Culka
- Institute of Biology and Ecology, Department of Cellular Biology, P. J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
| | - Peter Fedorocko
- Institute of Biology and Ecology, Department of Cellular Biology, P. J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
| | - Maria Kozurkova
- Institute of Chemistry, Department of Biochemistry, P. J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic.
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Janockova J, Gulasova Z, Musilek K, Kuca K, Kozurkova M. Novel cholinesterase modulators and their ability to interact with DNA. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 115:364-369. [PMID: 23851179 DOI: 10.1016/j.saa.2013.06.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/23/2013] [Accepted: 06/04/2013] [Indexed: 06/02/2023]
Abstract
In the present work, an interaction of four cholinesterase modulators (1-4) with calf thymus DNA was studied via spectroscopic techniques (UV-Vis, fluorescent spectroscopy and circular dichroism). From UV-Vis spectroscopic analysis, the binding constants for DNA-pyridinium oximes complexes were calculated (K=3.5×10(4) to 1.4×10(5)M(-1)). All these measurements indicated that the compounds behave as effective DNA-interacting agents. Electrophoretic techniques proved that ligand 2 inhibited topoisomerase I at a concentration 5μM.
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Affiliation(s)
- Jana Janockova
- Institute of Chemistry, Department of Biochemistry, P.J. Šafárik University, Faculty of Science, Moyzesova 11, 04001 Kosice, Slovak Republic
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Lorke DE, Nurulain SM, Hasan MY, Kuča K, Petroianu GA. Prophylactic administration of non-organophosphate cholinesterase inhibitors before acute exposure to organophosphates: assessment using terbufos sulfone. J Appl Toxicol 2013; 34:1096-103. [PMID: 24136594 DOI: 10.1002/jat.2939] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/04/2013] [Accepted: 09/04/2013] [Indexed: 01/03/2023]
Abstract
Poisoning with organophosphorus compounds (OPCs) poses a serious threat worldwide. OPC-induced mortality can be significantly reduced by prophylactic administration of reversible acetylcholinesterase (AChE) inhibitors. The only American Food and Drug Administration (FDA)-approved substance for such pre-treatment (to soman exposure) is presently pyridostigmine, although its efficacy is controversial. In search for more efficacious and broad-spectrum alternatives, we have assessed in vivo the mortality-reducing efficacy of a group of five compounds with known AChE inhibitory activity (pyridostigmine, physostigmine, ranitidine, tacrine and K-27), when given in equitoxic dosage (25% of LD01 ) 30 min before exposure to the OPC terbufos sulfone. Protection was quantified in rats by determining the relative risk of death (RR) using Cox analysis, with RR = 1 for animals given only terbufos sulfone, but no pre-treatment. All tested AChE inhibitors reduced terbufos sulfone-induced mortality significantly (p ≤ 0.05) as compared with the non-treatment group (RR = 1: terbufos sulfone only). Best in vivo protection from terbufos sulfone-induced mortality was achieved, when K-27 was given before terbufos sulfone exposure (RR = 0.06), which was significantly (P ≤ 0.05) superior to the pre-treatment with all other tested compounds, for example tacrine (RR = 0.21), pyridostigmine (RR = 0.28), physostigmine (RR = 0.29) and ranitidine (RR = 0.33). The differences in efficacy between tacrine, pyridostigmine, physostigmine and ranitidine were not statistically significant. Prophylactic administration of an oxime (such as K-27) in case of imminent OPC exposure may be a viable option.
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Affiliation(s)
- Dietrich E Lorke
- Department of Cellular Biology & Pharmacology, Florida International University, Miami, Florida, USA; Department of Anatomy, FMHS, UAE University, Al Ain, United Arab Emirates
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18
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Gupta B, Sharma R, Singh N, Kuca K, Acharya JR, Ghosh KK. In vitro reactivation kinetics of paraoxon- and DFP-inhibited electric eel AChE using mono- and bis-pyridinium oximes. Arch Toxicol 2013; 88:381-90. [PMID: 24065055 DOI: 10.1007/s00204-013-1136-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 09/12/2013] [Indexed: 11/25/2022]
Abstract
Oxime-assisted reactivation of organophosphate (OP)-inhibited acetylcholinesterase (AChE) is a crucial step in the post-inhibitory treatment of OP intoxication. The limited efficacy of oxime reactivators for all OP nerve agents and pesticides led to the development of various novel oximes and their thorough kinetic investigations. Hence, in the present investigation, we have tested 10 structurally different pyridinium oxime-based reactivators for their in vitro potency to reactivate paraoxon- and DFP-inhibited electric eel AChE. From structure activity relationship point of view, various oximes such as mono-quaternary (2-PAM, K100, K024) and bis-quaternary symmetric (obidoxime, TMB-4) and asymmetric (K027, K048, K203, K618, K628) oximes bearing different connecting linkers (oxybismethylene, trimethylene, propane, butane, butene, and xylene) have been studied. The observed kinetic data demonstrate that not only the position of oxime group is decisive for the increased reactivation ability of oximes, but the role of connecting linker is also significant. Oximes with aliphatic linkers are superior reactivators than the oximes with unsaturated and aromatic linkers. The optimal chain length for plausible reactivation ability for paraoxon- and DFP-inhibited AChE is 3 or 4 carbon-carbon connecting linker between prydinium rings.
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Affiliation(s)
- Bhanushree Gupta
- School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur, 492010, CG, India
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19
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Pharmacokinetics of acetylcholinesterase reactivator K203 and consequent evaluation of low molecular weight antioxidants/markers of oxidative stress. J Appl Biomed 2012. [DOI: 10.2478/v10136-011-0015-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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20
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Petroianu GA, Nurulain SM, Shafiullah M, Hasan MY, Kuča K, Lorke DE. Usefulness of administration of non-organophosphate cholinesterase inhibitors before acute exposure to organophosphates: assessment using paraoxon. J Appl Toxicol 2012; 33:894-900. [PMID: 22611016 DOI: 10.1002/jat.2760] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 02/28/2012] [Accepted: 02/28/2012] [Indexed: 11/11/2022]
Abstract
Reversible acetylcholinesterase (AChE) inhibitors can protect against the lethal effects of irreversible organophosphorus AChE inhibitors (OPCs), when administered before OPC exposure. We have assessed in vivo the mortality-reducing efficacy of a group of known AChE inhibitors, when given in equitoxic dosage before exposure to the OPC paraoxon. Protection was quantified in rats by determining the relative risk (RR) of death. Best in vivo protection from paraoxon-induced mortality was observed after prophylactic administration of physostigmine (RR = 0.30) or the oxime K-27 (RR = 0.34); both treatments were significantly superior to the pre-treatment with all other tested compounds, including the established substance pyridostigmine. Tacrine (RR = 0.67), ranitidine (RR = 0.72), pyridostigmine (RR = 0.76), tiapride (RR = 0.80) and 7-MEOTA (RR = 0.86) also significantly reduced the relative risk of paraoxon-induced death, but to a lesser degree. Methylene blue, amiloride and metoclopramide had an unfavorable effect (RR ≥ 1), significantly increasing mortality. When CNS penetration by prophylactic is undesirable K-27 is a promising alternative to pyridostigmine.
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Affiliation(s)
- Georg A Petroianu
- Department of Cellular Biology & Pharmacology, Florida International University, Miami, FL 33199, USA.
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21
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Kassa J, Karasova JZ, Sepsova V, Caisberger F, Bajgar J. A comparison of the reactivating and therapeutic efficacy of chosen combinations of oximes with individual oximes against VX in rats and mice. Int J Toxicol 2012; 30:562-7. [PMID: 22013137 DOI: 10.1177/1091581811415294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The ability of 2 combinations of oximes (HI-6 + trimedoxime and HI-6 + K203) to reactivate VX-inhibited acetylcholinesterase and reduce acute toxicity of VX was compared with the reactivating and therapeutic efficacy of antidotal treatment involving a single oxime (HI-6, trimedoxime, K203) in rats and mice. Our results showed that the reactivating efficacy of both combinations of oximes studied in rats is significantly higher than the reactivating efficacy of all individual oximes in diaphragm and roughly corresponds to the most effective individual oxime in blood and brain. Both combinations of oximes were found to be more effective in the reduction of acute lethal toxicity of VX in mice than the antidotal treatment involving the most efficacious individual oxime although the difference is not significant. Based on the obtained data, we can conclude that the antidotal treatment involving the chosen combinations of oximes brings benefit for the reactivation of VX-inhibited acetylcholinesterase in rats and for the antidotal treatment of VX-induced acute poisoning in mice.
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Affiliation(s)
- Jiri Kassa
- Department of Toxicology, Faculty of Military Health Sciences, Hradec Kralove, Czech Republic.
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22
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Mehretie S, Losada J, Tessema M, Admassie S, Solomon T, Perez-Pariente J, Díaz I. Stripping voltammetric determination of pyridine-2-aldoxime methochloride at the iron(iii) doped zeolite modified glassy carbon electrode. Analyst 2012; 137:5625-31. [DOI: 10.1039/c2an35851d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Musilek K, Komloova M, Holas O, Horova A, Pohanka M, Gunn-Moore F, Dohnal V, Dolezal M, Kuca K. Mono-oxime bisquaternary acetylcholinesterase reactivators with prop-1,3-diyl linkage—Preparation, in vitro screening and molecular docking. Bioorg Med Chem 2011; 19:754-62. [DOI: 10.1016/j.bmc.2010.12.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 12/05/2010] [Accepted: 12/07/2010] [Indexed: 11/30/2022]
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Lorke DE, Hasan MY, Nurulain SM, Shafiullah M, Kuča K, Petroianu GA. Pretreatment for acute exposure to diisopropylfluorophosphate: in vivo efficacy of various acetylcholinesterase inhibitors. J Appl Toxicol 2010; 31:515-23. [PMID: 20981864 DOI: 10.1002/jat.1589] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 08/18/2010] [Accepted: 08/19/2010] [Indexed: 11/06/2022]
Abstract
Prophylactic administration of reversible acetylcholinesterase (AChE) inhibitors before exposure to organophosphorus compounds (OPCs) can reduce OPC-induced mortality. Pyridostigmine is the only FDA-approved substance for such use. The AChE-inhibitory activity of known AChE inhibitors was quantified in vitro and their in vivo mortality-reducing efficacy was compared, when given prophylactically before the exposure to the OPC diisopropylfluorophosphate (DFP). The IC50 was measured in vitro for the known AChE inhibitors pyridostigmine, physostigmine, ranitidine, tiapride, tacrine, 7-methoxytacrine, amiloride, metoclopramide, methylene blue and the experimental oxime K-27. Their in vivo efficacy, when given as pretreatment, to protect rats from DFP-induced mortality was quantified by determining the relative risk of death (RR) by Cox analysis, with RR = 1 for animals given only DFP, but no pretreatment. Physostigmine was the strongest in vitro AChE-inhibitor (IC50 = 0.012 µ m), followed by 7-methoxytacrine, tacrine, pyridostigmine and methylene blue. Ranitidine (IC50 = 2.5 µ m), metoclopramide and amiloride were in the mid-range. Tiapride (IC50 = 256 µ m) and K-27 (IC50 = 414 µ m) only weakly inhibited RBC AChE activity. Best in vivo protection from DFP-induced mortality was achieved when physostigmine (RR = 0.02) or tacrine (RR = 0.05) was given before DFP exposure, which was significantly superior to the pretreatment with all other tested compounds, except K-27 (RR = 0.18). The mortality-reducing effect of pyridostigmine, ranitidine and 7-methoxytacrine was inferior, but still significant. Tiapride, methylene blue, metoclopramide and amiloride did not significantly improve DFP-induced mortality. K-27 may be a more efficacious alternative to pyridostigmine, when passage into the brain precludes administration of physostigmine or tacrine.
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Affiliation(s)
- Dietrich E Lorke
- Department of Anatomy, FMHS, UAE University, Al Ain, UAE; Department of Cellular Biology and Pharmacology, Florida International University, Miami, FL, USA
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Kuca K, Musilek K, Jun D, Pohanka M, Ghosh KK, Hrabinova M. Oxime K027: novel low-toxic candidate for the universal reactivator of nerve agent- and pesticide-inhibited acetylcholinesterase. J Enzyme Inhib Med Chem 2010; 25:509-12. [PMID: 20192902 DOI: 10.3109/14756360903357569] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Oxime K027 is a low-toxic bisquaternary compound originally developed as a reactivator of acetylcholinesterase (AChE) inhibited by nerve agents. The reactivation potency of K027 has been tested as a potential reactivator of AChE inhibited by tabun, sarin, cyclosarin, soman, VX, Russian VX, paraoxon, methylchlorpyrifos, and DDVP. The results show that oxime K027 reactivated AChE inhibited by almost all tested inhibitors to more than 10%, which is believed to be enough for saving the lives of intoxicated organisms. In the case of cyclosarin- and soman-inhibited AChE, oxime K027 did not reach sufficient reactivation potency.
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Affiliation(s)
- Kamil Kuca
- Center of Advanced Studies, Faculty of Military Health Sciences, University of Defense, Trebesska, Hradec Kralove, Czech Republic.
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Musilek K, Holas O, Misik J, Pohanka M, Novotny L, Dohnal V, Opletalova V, Kuca K. Monooxime-monocarbamoyl Bispyridinium Xylene-Linked Reactivators of Acetylcholinesterase-Synthesis, In vitro and Toxicity Evaluation, and Docking Studies. ChemMedChem 2010; 5:247-54. [DOI: 10.1002/cmdc.200900455] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Musilek K, Dolezal M, Gunn-Moore F, Kuca K. Design, evaluation and structure-activity relationship studies of the AChE reactivators against organophosphorus pesticides. Med Res Rev 2009; 31:548-75. [PMID: 20027669 DOI: 10.1002/med.20192] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Organophosphate pesticides (OPPs; e.g. chlorpyrifos, diazinon, paraoxon) are a wide and heterogeneous group of organophosphorus compounds. Their biological activity of inhibiting acetylcholinesterase (AChE) or butyrylcholinesterase (BChE) ranks them as life endangering agents. The necessary treatment after OPP exposure involves the use of parasympatolytics (e.g. atropine), oxime reactivators (e.g. obidoxime), and anticonvulsive drugs (e.g. diazepam). Therefore, the reactivators of AChE are essential compounds in the treatment of OPP intoxications. Commercial AChE reactivators (e.g. pralidoxime, HI-6, obidoxime, trimedoxime, methoxime) were originally developed for other members of the organophosphate family, such as nerve agents (e.g. sarin, soman, tabun, VX). Pralidoxime, HI-6, and methoxime were found to be weak reactivators of OPP-inhibited AChE. Obidoxime and trimedoxime showed satisfactory reactivation against various OPPs with minor toxicity issues. During the last two decades, the treatment of OPP exposure has become more widely discussed because of growing agricultural production, industrialization, and harmful social issues (e.g. suicides). In this review is the summarized design, evaluation, and structure-activity relationship studies of recently produced AChE reactivators. Since pralidoxime, over 300 oximes have been produced or tested against OPP poisoning, and several novel compounds show very promising abilities as comparable (or higher) to commercial oximes. Some of these are highlighted for their further testing of OPP exposure and, additionally, the main structure-activity relationship of AChE reactivators against OPP is discussed.
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Affiliation(s)
- Kamil Musilek
- Department of Toxicology, Trebesska, Hradec Kralove, Czech Republic.
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Lorke DE, Petroianu GA. Minireview: does in-vitro testing of oximes help predict their in-vivo action after paraoxon exposure? J Appl Toxicol 2009; 29:459-69. [PMID: 19603416 DOI: 10.1002/jat.1457] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
K-oximes have recently been developed in the search for efficacious broad-band reactivators of acetylcholinesterase (AChE) inhibited by organophosphorus compounds (OPC). Before clinical use, their toxicity and efficacy need to be assessed, and there is clear demand for simple in vitro tests that can predict in vivo performance. This article summarizes our in vitro data obtained for conventional and experimental oximes in human and rat blood exposed to the OPC paraoxon and correlates them with our in vivo results. The intrinsic AChE inhibitory activity of oximes, as reflected by their in vitro IC(50), is strongly correlated with their LD(50) (rat): oximes with a high IC(50) (K-27, K-48, pralidoxime and obidoxime) also show a high LD(50) and are thus relatively non-toxic, whereas oximes K-105, K-108 and K-113 have a low IC(50), a low LD(50) and are far more toxic. The IC(50) is also correlated with the in vivo capacity to protect from paraoxon-induced mortality: oximes with a higher IC(50) reduce the relative risk of death more. In contrast, the protective ability as assessed in vitro by the slope of the IC(50) shift (tanalpha), is not correlated with in vivo protection from paraoxon-induced mortality: the best in vivo protectors (K-27 and K-48) show a much lower tanalpha value (around 2) than K-110 and K-113 (tanalpha around 10), which hardly reduce the relative risk of death after paraoxon exposure. The partition coefficient logP of the individual oximes is inversely correlated with their IC(50) and with their LD(50) and is therefore an indicator of toxicity: strongly hydrophilic oximes tend to be less toxic than less hydrophilic ones. These data highlight the good predictive value of in vitro IC(50) testing for in vivo toxicity and the limited practical significance of in vitro assessment of protective potency.
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Affiliation(s)
- D E Lorke
- Department of Anatomy, FMHS, UAE University, Al Ain, UAE
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Kassa J, Karasova JZ, Caisberger F, Bajgar J. The influence of combinations of oximes on the reactivating and therapeutic efficacy of antidotal treatment of soman poisoning in rats and mice. Toxicol Mech Methods 2009; 19:547-51. [DOI: 10.3109/15376510903350371] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kuča K, Musílek K, Jun D, Pohanka M, Žďárová Karasová J, Novotný L, Musilová L. Could oxime HI-6 really be considered as "broad-spectrum" antidote? J Appl Biomed 2009. [DOI: 10.32725/jab.2009.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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