In vitro inhibition of glutathione S-transferases by several insecticides and allelochemicals in two moth species

Abstract

Glutathione S-transferases (GSTs) are important detoxification enzymes in insects. This study examined the inhibitory effects of five insecticides (beta-cypermethrin, fenpropathrin, phoxim, abamectin, acetamiprid) and two plant-derived allelochemicals (quercetin, tannic acid) on GST activity in Micromelalopha troglodyta (Graeser) and Clostera anachoreta (Fabricius). GST activities were suppressed by all the insecticides and allelochemicals tested; the two allelochemicals were the most potent inhibitors, reducing GST activity in vitro in a dosage-dependent manner. Kinetic analyses of GST inhibition by quercetin and tannic acid in M. troglodyta and C. anachoreta suggested biochemical differences in their GSTs.

Keywords:

• allelochemicals
• Clostera anachoreta (Fabricius)
• glutathione S-transferase
• insecticides
• Micromelalopha troglodyta (Graeser)

Acknowledgements

This research was supported by the National Natural Science Foundation of China [Contract No. 30600476, 30972376 and 31370652], a General Financial Grant from the China Postdoctoral Science Foundation [2013M530262] and the Priority Academic Program Development Fund of Jiangsu Higher Education Institutions. We thank Dr. Joe Zhou of Kentucky University and Dr. Steve Chambers, Metro Editor of The Star-Ledger “Daily News” for a critical reading of the English manuscript, and Youhui Gong in China Agricultural University and Xianghua Xu in Nanjing University of Information Science and Technology for the statistical analysis.