Larvicidal activity of ethanolic extract of Azadirachta indica against Aedes aegypti larvae

Abstract

Aedes aegypti is a mosquito that carries dengue virus, yellow fever and other diseases transmitted to humans. Organophosphorus larvicides are used to control the proliferation of this mosquito, which has generated a high degree of resistance; hence, new alternatives such as bio-larvicides formulated with plant extracts are of great interest. The aims of this study were to evaluate the ethanolic extract of Azadirachta indica leaves as a larvicide against Aedes aegypti and to determine the main compounds present in it by GC-MS. In the assay, three concentrations of ethanolic extract were used (10 mg L-1, 20 mg L-1, and 50 mg L-1). This was performed thrice against a positive control (commercial larvicide: spores and endotoxic crystals of Bacillus thuringiensis var. israelensis Serotype H-14) and negative control (water). After 72 h of incubation, it was observed higher larval mortality (93%) in the ethanolic extract at a concentration of 50 mg L-1; the extracts at 10 mg L-1 and 20 mg L-1 shown larval mortality of 47% and 70%, respectively. The majority compound determined by the GC-MS analysis was phytol (14.4% area). The results obtained in this study demonstrated the larvicidal potential of the ethanolic extract of A. indica against larvae of A. aegypti.

Phytochemical composition of almond oil from Melia azedarach L. and its larvicidal, ovicidal, repellent and enzyme activities in Culex pipiens L.

“…All concentrations of emulsified Neem oil above 1000 ppm (0.5-10%), caused 100% mortality against the third and the fourth instar larvae within 24 hours. Effectiveness results of M. azedarach insecticidal extracts coincide with those obtained by other authors, such as Manzano et al (2020) who evaluated the larvicidal effect of Neem extract on Aedes aegypti larvae. The best larvicidal activity (93% mortality) was obtained at 72 hours of 50 mg/L -1 extract.…”

Larvicidal activity of vegetable oils against Aedes aegypti larvae

“…During the other four exposure periods, no statistical difference between the treatments was observed (Table 1). The ethanolic extract of Azadichta indica at the dose of 50 mg L -1 caused 93% mortality of A. aegypti larvae after 72 h of exposure (Manzano et al, 2020). According to Abbot's efficiency test, represented by the values in parentheses, the oil of M. flexuosa was the most efficient after 24 h of exposure, with almost 36%, followed by C. nucifera and C. coriaceum with 30.77 and 20.51%, respectively (Table 1).…”

In silico molecular docking study of plant-based compounds from medicinal plant Lantana camara L. against Aedes aegypti L. protein

“…The ethanolic extract A. indica determined the presence of compound palmitic acid reported to have larvicidal against Ae. Aegypti [62] . Gamolenic acid, or gamma-linolenic acid (γ-Linolenic acid) or GLA, is an essential fatty acid (EFA) reported to have antimicrobial activities against serval oral pathogenic bacteria including Aggregatibacter actinomycetemcomitans, Candida albicans, Fusobacterium nucleatum subsp.…”