Effects of piperonyl butoxide on the toxicity of the organophosphate temephos and the role of esterases in the insecticide resistance of Aedes aegypti

• Published in: Revista da Sociedade Brasileira de Medicina Tropical
• Main Authors: Boscolli Barbosa Pereira, Jean Ezequiel Limongi, Edimar Olegário de Campos Júnior, Denis Prudencio Luiz, Warwick Estevam Kerr
• Format: Article in Journal/Newspaper
• Language: English
• Published: Sociedade Brasileira de Medicina Tropical (SBMT) 2014
• Subjects: Temephos; Insecticide resistance; Aedes aegypti; Esterases; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doi.org/10.1590/0037-8682-0195-2014; https://doaj.org/article/10106f53215043ab9cce30c488e83a6a

Introduction The effects of piperonyl butoxide (PBO) on the toxicity of the organophosphate temephos (TE) and the role of esterases in the resistance of Aedes aegypti to this insecticide were evaluated. Methods A. aegypti L4 larvae susceptible and resistant to TE were pre-treated with PBO solutions in acetone at concentrations of 0.125, 0.25, 0.5, 1, and 2% for 24h and subsequently exposed to a diagnostic concentration of 0.02mg/L aqueous TE solution. The esterase activity of the larvae extracts pre-treated with varying PBO concentrations and exposed to TE for three time periods was determined. Results At concentrations of 0.25, 0.5, 1, and 2%, PBO showed a significant synergistic effect with TE toxicity. High levels of esterase activity were associated with the survival of A. aegypti L4 larvae exposed to TE only. Conclusions The results of the biochemical assays suggest that PBO has a significant inhibitory effect on the total esterase activity in A. aegypti larvae.