title: Assessment of A Simple Compound-Saving Method To Study Insecticidal Activity of Natural Extracts and Pure Compounds Against Mosquito Larvae.
abstract: Research on natural insecticides has intensified with the spread of resistance to chemicals among insects, particularly disease vectors. To evaluate compounds, the World Health Organization (WHO) has published standardized procedures. However, those may be excessively compound-consuming when it comes to assessing the activity of natural extracts and pure compounds isolated in limited amount. As part of our work on the discovery of new mosquito larvicides from Amazonian plants, we developed a compound-saving assay in 5-ml glass tubes instead of WHO larval 100-ml cups. Comparing activity of synthetic and natural chemicals validated the glass tube assay. Raw data, lethal doses that kill 50% (LD50) and 90% (LD90) at 24 and 48 h, were highly correlated (0.68 < R2< 0.96, P < 0.001, Pearson test) between cups and tubes. It was also established that 10 tubes (N = 50 larvae) provided the same level of sensitivity as 20 tubes (N = 100). This method proved suitable for rapid screening of natural extracts and molecules, identifying active compounds using 10 times less material than in the WHO protocol.
authors.forename: Michaël
authors.initials: M
authors.lastname: Falkowski
authors.forename: Arnaud
authors.initials: A
authors.lastname: Jahn-Oyac
authors.forename: Emma
authors.initials: E
authors.lastname: Ferrero
authors.forename: Jean
authors.initials: J
authors.lastname: Issaly
authors.forename: Véronique
authors.initials: V
authors.lastname: Eparvier
authors.forename: Romain
authors.initials: R
authors.lastname: Girod
authors.forename: Alice M S
authors.initials: AM
authors.lastname: Rodrigues
authors.forename: Didier
authors.initials: D
authors.lastname: Stien
authors.forename: Emeline
authors.initials: E
authors.lastname: Houël
authors.forename: Isabelle
authors.initials: I
authors.lastname: Dusfour
mesh_terms: D000330:Aedes / Q000187:drug effects* / Q000254:growth & development; D000818:Animals; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D009032:Mosquito Control / Q000379:methods*; D010936:Plant Extracts / Q000737:chemistry / Q000633:toxicity*
chemical_list: D007306:Insecticides; D010936:Plant Extracts
keywords: Mosquitoes; natural insecticides; screening method