title: Insecticidal activity of an essential oil of Tagetes patula L. (Asteraceae) on common bed bug Cimex lectularius L. and molecular docking of major compounds at the catalytic site of ClAChE1.
abstract: Emerging resistance to insecticides has influenced pharmaceutical research and the search for alternatives to control the common bed bug Cimex lectularius. In this sense, natural products can play a major role. Tagetes patula, popularly known as dwarf marigold, is a plant native to North America with biocide potential. The aim of this work was to evaluate the biological activity of T. patula essential oil (EO) against adult common bed bugs via exposure to dry residues by the Impregnated Paper Disk Test (IPDT) using cypermethrin as a positive control. We selected the enzyme acetylcholinesterase as a target for modeling studies, with the intent of investigating the molecular basis of any biological activity of the EO. Chemical analysis of the EO was performed using gas chromatography coupled to mass spectrometry (GC-MS). Additionally, oral and dermal acute toxicity tests were performed according to Organization for Economic Cooperation and Development (OECD) guidelines. The sulforhodamine B assay (SRB) was performed to verify the cytotoxicity of EO to HaCaT cells. The EO eliminated 100 % of the bed bugs at 100 mg mL-1with an LC50value of 15.85 mg mL-1. GC-MS analysis identified α-terpinolene, limonene, piperitenone, and piperitone as major components of the mixture. Molecular modeling studies of these major compounds suggested that they are acetylcholinesterase inhibitors with good steric and electronic complementarity. The in vitro cytotoxicity evaluation revealed a LC50= 37.06 μg mL-1and in vivo acute toxicity showed an LC50>4000 mg kg-1, indicating that the EO presents low risk of toxic side effects in humans. The T. patula essential oil components provide a promising strategy for controlling bed bug populations with low mammalian toxicity. These findings pave the way for further in vivo studies aimed at developing a safe and effective insecticide.
authors.affiliation: Department of Organic Chemistry, Institute of Chemistry, University Estadual Paulista-UNESP, Rua Prof. Francisco Degni 55, Quitandinha, Araraquara, SP, CEP 14800-060, Brazil. flaviopoliti@hotmail.com.
authors.forename: Flávio Augusto Sanches
authors.initials: FA
authors.lastname: Politi
authors.affiliation: Faculdade de Ciências Farmacêuticas, University Estadual Paulista-UNESP, Rod. Araraquara-Jaú Km 01, Araraquara, SP, 14801-902, Brazil.
authors.forename: Juliana Damieli
authors.initials: JD
authors.lastname: Nascimento
authors.affiliation: Department of Organic Chemistry, Institute of Chemistry, University Estadual Paulista-UNESP, Rua Prof. Francisco Degni 55, Quitandinha, Araraquara, SP, CEP 14800-060, Brazil.
authors.forename: Alexander Alves
authors.initials: AA
authors.lastname: da Silva
authors.affiliation: Faculdade de Ciências Farmacêuticas, University Estadual Paulista-UNESP, Rod. Araraquara-Jaú Km 01, Araraquara, SP, 14801-902, Brazil.
authors.forename: Isabela Jacob
authors.initials: IJ
authors.lastname: Moro
authors.affiliation: Centro de Pesquisa e Inovação em Biodiversidade e Fármacos, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, 13563-120, Brazil.
authors.forename: Mariana Lopes
authors.initials: ML
authors.lastname: Garcia
authors.affiliation: Centro de Pesquisa e Inovação em Biodiversidade e Fármacos, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, 13563-120, Brazil.
authors.forename: Rafael Victório Carvalho
authors.initials: RV
authors.lastname: Guido
authors.affiliation: Faculdade de Ciências Farmacêuticas, University Estadual Paulista-UNESP, Rod. Araraquara-Jaú Km 01, Araraquara, SP, 14801-902, Brazil.
authors.forename: Rosemeire Cristina Linhari Rodrigues
authors.initials: RC
authors.lastname: Pietro
authors.affiliation: Centro de Assistência Toxicológica (CEATOX), University Estadual Paulista-UNESP, Distrito de Rubião Júnior s/n, Botucatu, SP, 18618-970, Brazil.
authors.forename: Antônio Francisco
authors.initials: AF
authors.lastname: Godinho
authors.affiliation: Department of Organic Chemistry, Institute of Chemistry, University Estadual Paulista-UNESP, Rua Prof. Francisco Degni 55, Quitandinha, Araraquara, SP, CEP 14800-060, Brazil.
authors.forename: Maysa
authors.initials: M
authors.lastname: Furlan
mesh_terms: D000818:Animals; D001511:Bedbugs / Q000187:drug effects*; D020134:Catalytic Domain; D008401:Gas Chromatography-Mass Spectrometry; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D062105:Molecular Docking Simulation; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D031686:Tagetes / Q000737:chemistry*
chemical_list: D007306:Insecticides; D009822:Oils, Volatile; D010938:Plant Oils
keywords: Acetylcholinesterase inhibitors; Homology modeling; Insecticide resistance; Natural products