Chemical Composition, Larvicidal Activity, and Enzyme Inhibition of the Essential Oil of Lippia grata Schauer from the Caatinga Biome against Dengue Vectors

Abstract

Insect resistance and environmental pollution are among the drawbacks of continuous use of synthetic insecticides against the vectors of dengue, Aedes aegypti and Aedes albopictus. The objective of this study was to analyze the composition of the essential oil of Lippia grata Schauer collected from plants, in three periods of the year, to compare the larvicidal activity and enzymatic inhibition of the dengue vectors. The oilsanalyzed by gas chromatography coupled to mass spectrometry (GC-MS), presented thymol and 1,8-cineole, as the main constituents, in all three periods. This composition was different from that found in previous studies of the species from different places, thus, suggesting a new chemotype of Lippia grata. Larvicidal tests were performed at concentrations of 100, 75, 50, 25, and 12.5 μg.mL−1 and the essential oil from the rainy season showed the best results, with LC50 of 22.79 μg.mL−1 and 35.36 μg.mL−1 against Ae. aegypti and Ae. albopictus, respectively; this result was better than other reports. In the rainy period, however, there was a greater variety of components, which led to a better larvicidal effect, possibly due to synergistic action with minor constituents. Total proteins, amylases, and acetylcholinesterase of both species were inhibited by the oils.

The essential oil ofSchinus terebinthifoliusand its nanoemulsion and isolated monoterpenes: investigation of their activity againstCulex pipienswith insights into the adverse effects on non‐target organisms

“…One approach is the application of plant‐based products, particularly plant essential oils (EOs), where EOs have exhibited promising bioactivities against harmful insects, including mosquitoes 6–11 . In this regard, plant EOs seem more appropriate as pest control agents than chemical pesticides, even though the latter are more potent.…”

“…One approach is the application of plant-based products, particularly plant essential oils (EOs), where EOs have exhibited promising bioactivities against harmful insects, including mosquitoes. [6][7][8][9][10][11] In this regard, plant EOs seem more appropriate as pest control agents than chemical pesticides, even though the latter are more potent. Natural products, including EOs, are economically feasible, biodegrade to non-toxic metabolites, commonly have low toxicity towards beneficial non-target species, and exert their action through multiple mechanisms.…”

Larvicidal Activity of Ethanol Extract of Cinnamomum sintoc Blume Bark against Aedes aegypti: Role of the Extract as an Acetylcholinesterase Enzyme Inhibitor

“…Some of these results suggest that the potential of these plants as larvicides is due to the phytochemical compounds that can act as inhibitors of the enzyme acetylcholinesterase in larvae. 13 Cinnamomum sintoc Bl is a plant that grows in the South Kalimantan region. This plant contains phytochemical compounds and has the potential to be utilized as antioxidant, antifungal, and antibacterial.…”

Bioactivity and safety evaluations of Cupressus sempervirens essential oil, its nanoemulsion and main terpenes against Culex quinquefasciatus Say

“…Thus, the chances of pests developing resistance to such materials are less likely (Isman 2015;Benelli and Pavela 2018a, b;Garay et al 2020). Undoubtedly, EOs and their bioactive components, especially monoterpenes, are good examples as biorational pest control options, as many of them have shown promising bioactivities against harmful insects, including mosquito vectors (Karr and Coats 1988;Benelli and Pavela 2018a, b;Benelli et al 2018;Bortolucci et al 2019;Hung et al 2020;de Souza et al 2020;Manh and Tuyet 2020;Lima et al 2021;Nakasen et al 2021;Felix et al 2021;Pavela et al 2021a, b). The genus Cupressus (Cupressaceae) includes plants that are widespread in North America, the Mediterranean Basin and the subtropical western part of Asia, including Saudi Arabia (Rguez et al 2018).…”