Chemical Composition, Molecular Docking and Larvicidal Activity of Citrus x Limon (L) Osbeck Essential Oil

Abstract

Introduction: The mosquito Aedes aegypti is the primary vector of arboviruses of major public health concern, including dengue, Zika, chikungunya, and yellow fever. Chemical larvicides are commonly used to control Aedes aegypti; however, despite their efficacy, they pose environmental risks and may lead to resistance. Essential oils, such as that from Citrus limon, have emerged as sustainable alternatives due to their larvicidal activity, low toxicity, biodegradability, and chemical complexity, which reduces the likelihood of resistance development. Objective: This study describes the chemical composition of the essential oil distilled from the peels of Citrus × limon (L.) Osbeck and evaluates its biological activity against third-instar larvae of Aedes aegypti. Methods: The essential oil was extracted by hydrodistillation, and its components were identified by gas chromatography coupled with mass spectrometry (GC/MS). Larvicidal activity was assessed, and the lethal concentration was determined using the Probit method. The oil's mechanism of action was investigated through molecular docking studies. Results and Discussion: Analyses revealed that the oil is predominantly composed of monoterpenes, with limonene as the major component (75.77%), followed by o-cymene (9.24%) and β-pinene (7.48%). Furthermore, the oil exhibited larvicidal activity, with a lethal concentration of 44.11 µg/mL. Molecular docking studies showed significant interactions between the main compounds and target proteins, with binding affinities ranging from –5.97 to –6.56 kcal/mol for acetylcholinesterase and sterol carrier protein-2, suggesting a multi-target mechanism of action. Conclusions: The essential oil from Citrus × limon is therefore active and shows potential as a replacement for synthetic larvicides.