Effects of 4‐hexylresorcinol on the phenoloxidase from Hyphantria cunea (Lepidoptera: Arctiidae): In vivo and in vitro studies. (29th September 2014)

• Record Type: Journal Article
• Authors: Sharifi, Mahboobeh; Ghadamyari, Mohammad; Sajedi, Reza H.; Mahmoodi, Nosrat O.
• Is Part Of: Insect science. Volume 22:Number 5(2015:Oct.)
• Page Start: 639
• Page End: 650
• Publication Date: 2014-09-29
• Subjects: Insects -- Periodicals; Entomology -- Periodicals; 595.705
• DOI: 10.1111/1744-7917.12154
• Languages: English
• ISSNs: 1672-9609

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>Insecticidal effects of 4‐hexylresorcinol, a phenoloxidase (PO) inhibitor, were determined on <italic>Hyphantria cunea</italic> (Drury) under laboratory conditions. The LC<sub>50</sub> for the 15‐d‐old larvae was estimated to be 2.95 g/L after 96 h exposure. The activities of glutathione <italic>S</italic>‐transferase (GST) and PO showed a decrease in larvae treated with 4‐hexylresorcinol, and the IC<sub>50</sub> of GST and PO were estimated to be 0.8 and 0.43 g/L, respectively, 24 h after treatment. The PO from the hemolymph of fall webworm was purified by ammonium sulfate precipitation, gel‐filtration, and ion‐exchange chromatography, and then enzymatic characteristics and the mechanism of inhibition were determined using L‐dihydroxyphenylalanine (L‐DOPA) as the substrate. The purified PO showed a single band on SDS‐PAGE with a molecular weight of about 70 kDa. The optimum pH for PO activity was observed at pH 7.0, optimum temperature was found to be 45 °C, and PO activity was strongly inhibited by Zn<sup>2+</sup>. IC<sub>50</sub> values were estimated to be 8.2, 19.14, and 24.04 μmol/L for 4‐hexylresorsinol, kojic acid, and quercetin, respectively. The inhibitory potencies (i.e., I<sub>50</sub> of each compound/I<sub>50</sub> of 4‐hexylresorcinol) of kojic acid and quercetin on <italic>H. cunea</italic> PO were estimated to be 1.87 and 2.89, respectively. 4‐hexylresorcinol was determined to be a competitive inhibitor, and kojic acid and quercetin were determined to be mixed inhibitors. PO is one of the most important enzymes in an insect's immune system, and the use of PO inhibitors seems to be a promising approach for pest control due to their potential safety for humans.</p> </abstract>