Enzymatic detoxification of organophosphorus pesticides and related toxicants

Abstract

Millions of cases of pesticide intoxication occur yearly and represent a public health problem. In addition, pesticide poisoning is the preferred suicidal method in rural areas. The use of enzymes for the treatment of intoxication due to organophosphorus pesticides was proposed decades ago. Several enzymes are able to transform organophosphorus compounds such as pesticides and nerve agents. Some specific enzymatic treatments have been proposed, including direct enzyme injection, liposome and erythrocytes carriers, PEGylated preparations and extracorporeal enzymatic treatments. Nevertheless, no enzymatic treatments are currently available. In this work, the use of enzymes for treating of organophosphorus pesticide intoxication is critically reviewed and the remaining challenges are discussed.

Microbial Phosphotriesterase: Structure, Function, and Biotechnological Applications

“…Currently, PTE and other OPH enzymes have emerged as one of the biocatalyst candidates for bioremediation purposes and the detoxification of agricultural pesticides as well as chemical warfare agents [3,34,39]. Since the OPs are not toxic to bacteria and some species of bacteria are also able to utilize OPs as a nutrient and carbon source, OPH bacteria like Pseudomonas, Aspergillus, Arthrobacter, and Chlorella have been used as organophosphate-degrading microorganisms [15,37,52,53].…”

“…The enzyme must be environmentally friendly, have activity/stability over broad pH and temperature ranges, and be stable in the presence of harsh solvents, metals, detergents, and/or denaturants (DTRA 2008) [8,56]. Contamination can occur in the air, water and soil [3,13,15]. As OP compounds can easily seep or dissolve into water, Istamboulie and his coworkers have tried to detoxify water using a PTE enzyme as the detoxification agent.…”

“…Contamination by these compounds may occur because of terrorist attacks, unsafe disposal methods, and spillage from poor handling by agricultural workers [2]. OP compounds are known to inhibit mammalian acetylcholinesterases (AChE) [3][4][5]. Acetylcholinesterase (AChE) is an enzyme that hydrolyzes the neurotransmitter acetylcholine (ACh) and serves as a regulator of neurotransmission [3].…”

“…OP compounds are known to inhibit mammalian acetylcholinesterases (AChE) [3][4][5]. Acetylcholinesterase (AChE) is an enzyme that hydrolyzes the neurotransmitter acetylcholine (ACh) and serves as a regulator of neurotransmission [3]. The most terrifying fact of its action is that the inhibition process is naturally irreversible, whereby the enzyme can no longer hydrolyze acetylcholine resulting in paralysis of muscles, seizures, difficulty in breathing and death by suffocation.…”

“…Unfortunately, most of these methods are expensive and may not suitable or even safe for the decontamination of human beings [7]. They may be very harsh and may not be very specific [3]. Currently, using enzymes is one of the more promising and safer ways to solve this problem.…”