The neurotoxic mechanism of Jack Bean Urease in insects involves the interplay between octopaminergic and dopaminergic pathways

• Published in: Pesticide biochemistry and physiology Vol. 189; p. 105290
• Main Authors: Barreto, Yuri Correia, Oliveira, Raquel Soares, Borges, Bruna Trindade, Rosa, Maria Eduarda, Zanatta, Ana Paula, de Almeida, Carlos Gabriel Moreira, Vinadé, Lúcia, Carlini, Celia Regina, Belo, Cháriston André Dal
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2023
• Subjects: Animals; Cockroaches; Jack bean urease; Mianserin - pharmacology; Monoaminergic pathways; Natural insecticides; Nauphoeta cinerea cockroaches; Neurolocomotor disturbance; Phentolamine - pharmacology; Reserpine - pharmacology; Urease - pharmacology; Nauphoeta cinerea cockroaches; Neurolocomotor disturbance; Monoaminergic pathways; Natural insecticides; Jack bean urease
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1016/j.pestbp.2022.105290

In the last decades, the entomotoxicity of JBU and its derived peptides became an object of study, due mainly to the ubiquitous interaction of these compounds with different species of insects and their potential as natural insecticides. In this work, we investigated the neurotoxic effects of JBU in Nauphoeta cinerea cockroaches by dissecting pharmacologically the monoaminergic pathways involved. Selective pharmacological modulators for monoaminergic pathways in in vivo and ex vivo experimental models were employed. Thus, the analysis of N. cinerea neurolocomotory behavior demonstrated that JBU (1.5 and 3 μg/g) induces a significant decrease in the exploratory activity. In these assays, pretreatment of animals with phentolamine, SCH23390 or reserpine, interfered significantly with the response of JBU. Using in vivo abductor metathoracic preparations JBU (1.5 μg/g) induced progressive neuromuscular blockade, in 120 min recordings. In this set of experiments, the previous treatment of the animals with phentolamine, SCH23390 or reserpine, completely inhibited JBU-induced neuromuscular blockade. The recordings of spontaneous compound neural action potentials in N. cinerea legs showed that JBU, only in the smallest dose, significantly decreased the number of potentials in 60 min recordings. When the animals were pretreated with phentolamine, SCH23390, or reserpine, but not with mianserin, there was a significant prevention of the JBU-inhibitory responses on the action potentials firing. Meanwhile, the treatment of the animals with mianserin did not affect JBU's inhibitory activity. The data presented in this work strongly suggest that the neurotoxic response of JBU in N. cinerea involves a cross talking between OCTOPAMIN-ergic and DOPAMIN-ergic nerve systems, but not the SEROTONIN-ergic neurotransmission. Further molecular biology studies with expression of insect receptors associated with voltage clamp techniques will help to discriminate the selectivity of JBU over the monoaminergic transmission. [Display omitted] •The entomotoxicity of Jack Bean Ureases involves locomotory deficits in insects;•The entomotoxicity of Jack Bean Ureases induces central and peripheral neurotoxicity;•Jack Bean Urease impairs Nauphoeta cinerea neuromuscular function;•Jack Bean Urease reduce the mechanoreption in Nauphoeta cinerea cockoraches;•The neurotoxic activity must be related to a octopaminergic-dopaminergic transduction.