Neurotoxic Mechanism of Bruceine A Biolarvicide Against Aedes aegypti Linnaeus Larvae

Abstract

Abstract: Background and Objectives: Aedes aegypti Linnaeus is a mosquito species that plays an important role as a vector of diseases in tropical and subtropical regions. Aedes aegypti (L.) resistance against temephos and pyrethroid has been widely reported in several countries including Indonesia. This study aimed to examine the neurotoxic mechanism of bruceine A biolarvicide and to determine the inhibitory activity of the enzyme acetylcholinesterase and gene Voltage-Gated Sodium Channel (VGSC) on A. aegypti (L.) larvae. Materials and Methods: Bruceine A was obtained by extraction and isolation of Makassar fruit’s seeds. Test of inhibition of acetylcholinesterase activity was based on Ellman method. Voltage-Gated Sodium Channel gene inhibitor was tested using PCR. The statistical analysis of inhibition of the enzyme acetylcholinesterase was performed by using Kruskal Wallis test followed by Mann Whitney. The data from observation on behavior response and VGSC gene were descriptively analyzed. Results: Bruceine A could inhibit the action of the enzyme acetylcholinesterase as much as 45.083±0.003%, with symptoms of a neurotoxic that is excitation, convulsions, tremors and paralysis. The result of fragment amplification of VGSC gene and electrophoresis on agarose gel 2% generated in a specific band with the size of the fragment bands of 336 bp on samples of larvae that were still sensitive to bruceine A and cypermethrin. Conclusion: Bruceine A isolated from the seeds of Brucea javanica (L.) Merr. has been demonstrated as biolarvicide against larvae of A. aegypti (L.), through its neurotoxic properties. The mechanism of neurotoxicity is mediated through inhibition of enzyme acetylcholinesterase and VGSC gene.