Acetylcholinesterase inhibitory potential of scorpion venom in Aedes aegypti (Diptera: Culicidae)

Potencial inibidor da acetilcolinesterase do veneno de escorpião em Aedes aegypti (Diptera: Culicidae)

Abstract

Scorpion venom contains a variety of neurotoxins which interact with ion channels and affect their activities. The present study was designed to evaluate the potential of scorpion venom as acetylcholinesterase (AChE) inhibitor by using Aedes aegypti as model organism. Venoms of two species, Hottentota tamulus (Fabricus, 1798) and Androctonus finitimus (Pocock, 1897) were selected for this study. Two peptides (36 kDa from H. tamulus and 54 kDa from A. finitimus) were separated from scorpion venom by using HPLC. Selected peptides caused significantly higher mortality in larvae and adults of Aedes aegypti than control (no mortalities were observed in control groups). Significant acetylcholinesterase (AChE) inhibitory potential of both peptides was recorded by spectrophotometer. The peptide of A. finitimus caused significantly higher mortality (95±1.53% in larvae and 100% in adults) than the peptide of H. tamulus (84.33±2.33% in larvae and 95.37±1.45% in adults). While H. tamulus peptide was more efficient in reducing AChE activity (0.029±0.012 in larvae and 0.03±0.003 in adults) than the peptide of A. finitimus (0.049±0.005 in larvae and 0.047±0.001 in adults). It was concluded that H. tamulus venom peptide was more efficiently reducing AChE activity, thus it could be a potential bio-insecticide which can be synthesized at industrial scale for the control of harmful insects.

Keywords:
scorpions; peptides; HPLC; AChE activity; Aedes aegypti