Lethal and sublethal effects of essential oil of Lippia sidoides (Verbenaceae) and monoterpenes on Chagas’ disease vector Rhodnius prolixus

Abstract

The aim of this study was to identify the composition of the essential oil from leaves of Lippia sidoides (EOLS), a typical shrub commonly found in the dry northeast of Brazil, popularly known as “alecrim-pimenta”. Additionally, we investigated the nymphicidal, ovicidal, phagoinhibitory and excretion effects of EOLS, its major constituent thymol and its isomer carvacrol, on fourth instar nymphs and eggs of Rhodnius prolixus, the Chagas’ disease vector. The nymphicidal and ovicidal activity of thymol, carvacrol, and EOLS was assessed by tests using impregnated Petri dishes. The lethal concentration values (LC50) for EOLS, carvacrol, and thymol were 54.48, 32.98, and 9.38 mg/cm2, respectively. The ovicidal test showed that both carvacrol and thymol (50 mg/cm2) inhibited hatching (50% and 23.3%, respectively), while treatments with 10 mg/cm2 or 50 mg/cm2 EOLS did not affect the hatching rate at all (80% and 90%, respectively). We observed an anti-feeding effect in insects fed with blood containing natural products at the higher concentrations (100 µg/mL). Finally, excretion rate was affected by EOLS and carvacrol, but not by thymol. These findings offer novel insights into basic physiological processes that make the tested natural compounds interesting candidates for new types of insecticides.

In Vitro Antibacterial and Antibiofilm Activity ofLippia albaEssential Oil, Citral, and Carvone againstStaphylococcus aureus

“…The chemical composition of the essential oil was analyzed according to Figueiredo et al [ 14 ]. A gas chromatograph coupled to a mass spectrometer (GC/MS, Shimadzu QP-2010 Plus) equipped with a Factor Four/VF (5 ms) fused-silica capillary column (30 m × 0.25 mm × 0.25 μ m film thickness), with helium as carrier gas at 1 mL min −1 , was used.…”

Plodia interpunctella (Lepidoptera: Pyralidae): Intoxication with essential oils isolated from Lippia turbinata (Griseb.) and analysis of neuropeptides and neuropeptide receptors, putative targets for pest control

“…The EOs from some Lippia spp. have shown toxicological effects on insects (Cavalcanti et al, 2004; Figueiredo et al, 2017; Gleiser & Zygadlo, 2007). Volatile oils are complex mixtures in which a variety of mono‐ and sesquiterpenes can be found; their biological activity is given by the combined activity of their components (Vera et al, 2014).…”

ATIVIDADE BRONCODILATADORA DO ÓLEO ESSENCIAL DE Lippia sidoides CHAM. EM BRONQUÍOLO ISOLADO DE Sus scrofa domesticus.

“…Sua infusão tem sido usada na medicina popular como aromoterápico, para rinite alérgica e no tratamento das infecções vaginais, boca e garganta (MATOS; OLIVEIRA, 1998). Várias ações biológicas da espécie L. sidoides que já estão documentadas na literatura, como: atividade antimicrobiana contra Staphylococcus aureus (SILVA et al, 2010), antifúngica em Curvularia luneta (DE SOUZA FERREIRA et al, 2018), inseticida em Rhodnius prolixus vetor da doença de Chagas (FIGUEIREDO et al, 2017), inibidor da excitabilidade nervosa em nervo ciático de ratos (BARBOSA et al, 2017), efeito antiespasmódico em traqueia de ratos (TEÓFILO, 2012). Por possuir efeito miorrelaxante em musculatura de vias aéreas de animais de experimentação e devido à grande variabilidade de resposta do musculo traquealis de diferentes espécies animais a um dado agente biológico, procuramos evidenciar se a espécie L. sidoides apresenta esse mesmo efeito em vias aéreas provenientes de animais de abatedouro.…”