Question

Which of the following is a cholinesterase inhibitor?

• A. Aldrin
• B. Malathion
• C. Endosulfan
• D. $\beta$-hexachlorocyclohexane

Answer 1

The correct option is B Malathion

Malathion is an organophosphate parasympathomimetic, which binds irreversibly to cholinesterase. Malathion is an insecticide of relatively low human toxicity. Malathion is a parasympathomimetic organophosphate compound that is used as an insecticide for the treatment of head lice. It inhibits acetylcholinesterase activity of most eukaryotes. Malathion is toxic to aquatic organisms, but has a relatively low toxicity for birds and mammals.

Cholinesterases catalyze the hydrolysis of the neurotransmitter acetylcholine into choline and acetic acid, a reaction necessary to allow a cholinergic neuron to return to its resting state after activation. Because of its essential function, chemicals that interfere with the action of cholinesterase are potent neurotoxins, causing muscle spasms and ultimately death. Thus, the correct answer is option B.