Bioactivity of Citral and Its Nanoparticle in Attenuating Pathogenicity of Pseudomonas aeruginosa and Controlling Drosophila melanogaster

Abstract

Plant-based essential oils are hydrophobic, volatile concentrate extracted from aromatic plants. They are the upcoming alternative and appealing source of antimicrobial compounds, citral (major constituent of lemongrass oil) being one of them, whose antiquorum sensing, in vivo delivery, and insecticidal potential need further exploration. Pseudomonas aeruginosa is one of the most prevalent, clinically lethal pathogens, which is resistible toward various treatments because of the inherent resistance acquired by the organism to many classes of drugs (multidrug resistant (MDR)). Moreover, fruit flies have been considered as the vectors of potentially lethal and opportunistic pathogens, including multiantibiotic-resistant microbes. As a result, controlling both the pathogen and its host vector are of utmost importance. The present study focused on the efficacy of essential oil of citral (EOC) and its nanoencapsulated form on quorum sensing inhibition (QSI) of P. aeruginosa PAO1 and its insecticidal activity against Drosophila melanogaster. Chitosan-based citral nanoparticles were synthesized and characterized using hydrodynamic size, zeta potential, polydispersity index, and field-emission scanning electron microscopy (FE-SEM). Citral nanoparticles at sub-minimum inhibitory concentration (MIC) exhibited QSI potential by attenuating biofilm formation (p-value < 0.05), while insecticidal activity of citral tested against D. melanogaster demonstrated toxicity of the EOC at a concentration of 3%–5%. Hence, the results elucidated the prospects of citral nanoparticles in the delivery of citral, which can be applied as a strategy to specifically target clinically lethal pathogens, major insect pests, and associated microbes.