Phytochemical Profiling and Larvicidal Activity of Ethanolic Extracts from Persea americana Mill. (Var. Lorena) Against Aedes aegypti

TL;DR

This study shows that extracts from Persea americana seeds are highly effective against mosquito larvae, suggesting potential for eco-friendly pest control.

Contribution

The study identifies seed extracts of Persea americana as a promising biopesticide with high larvicidal activity and rich phytochemical diversity.

Findings

Seed extract showed the highest larvicidal potency with an LC50 of 3.8 µg/mL.

UHPLC analysis revealed high chemical diversity in seed extracts compared to other plant parts.

Flavonoids, alkaloids, and saponins were identified as key bioactive compounds.

Abstract

Our study evaluated whether extracts obtained from the seeds, leaves, bark, fruit, peel of the fruit, root, and flowers of P. americana (var. Lorena) were lethal to Ae. aegypti larvae. Additionally, we determined the preliminary phytochemical, UV-Vis, and HPLC profiles of each extract. We found that the extracts differ in the richness and abundance of metabolites. These differences in phytochemical profiles are essential to explaining the extracts’ varying potencies against Ae. aegypti larvae. Notably, the seed extract showed the highest potency and is emerging as a promising ingredient for developing a biopesticide against this mosquito.

Dengue is a mosquito-borne viral disease transmitted by Aedes aegypti, the main vector in the Americas. The lack of effective antiviral treatments, limited vaccine coverage, and the increasing resistance of mosquitoes to conventional insecticides emphasize the need for alternative vector control strategies. Plant-derived larvicides represent a promising and eco-friendly approach. This study characterized the phytochemical profile of Persea americana Mill. (var. Lorena) and evaluated its larvicidal activity against Ae. aegypti (Rockefeller strain). The phytochemical profile was assessed through qualitative screening, UV-Vis spectrophotometry, and UHPLC analysis. Larvicidal activity was evaluated against third-instar larvae of Ae. aegypti (Rockefeller strain) and the median lethal concentration (LC50) values were determined. Preliminary screening of ethanolic extracts revealed the presence of various secondary metabolites of pharmacological relevance, including alkaloids, coumarins, tannins, flavonoids, saponins, triterpenes/sterols, and quinones. UV-Vis spectra displayed distinct absorption patterns, with a prominent peak near 260 nm, consistent with the presence of aromatic compounds. UHPLC profiling revealed high chemical diversity across different plant parts, with 70, 98, 71, and 52 peaks (above 1 × 105 intensity) detected in seed, flower, pulp, and leaf extracts, respectively. Larvicidal bioassays showed significant activity, particularly in the seed extract, with LC50 values (µg/mL) of 3.8 (3.3–4.1) for seeds, 22.4 (21.8–23.9) for flowers, 23.0 (21.5–24.6) for pulp, and 29.7 (28.1–31.2) for leaves. This study highlights the larvicidal potential of ethanolic extracts from P. americana (var. Lorena), with the seed extract exhibiting the highest chemical diversity and bioactivity against Ae. aegypti larvae. The detection of key secondary metabolites, including flavonoids, alkaloids, and saponins, supports the development of an effective, plant-based larvicide for sustainable vector control strategies.