Aegle marmelos-mediated zinc oxide nanoparticles for mosquito control, cancer therapy, and antibacterial applications

The study investigated the synthesis and characterization of zinc oxide nanoparticles (Am-ZnO-NPs) using Aegle marmelos leaves and their mosquitocidal, antioxidant, and anticancer efficacy. Am-ZnO-NPs were synthesized via combustion method under optimized conditions, including 5% plant extract, temperature of 70 °C, a contact time of 60 min, and pH of 10. The resulting nanoparticles were characterized using advanced analytical techniques. The Am-CuO-NPs were hexagonal wurtzite in shape and had an average particle size of 37.44 nm. The Am-CuO-NPs are highly stable with a surface charge of - 26.77 mV. Gas chromatography-mass spectrometry (GC-MS) analysis identified several compounds with insecticidal, antioxidant, and anticancer properties, including hexadecenoic acid, ethyl ester (25.61%), 9,12-octadecadienoic acid, ethyl ester (12.64%), and 9,12,15-octadecatrienoic acid, ethyl ester (6.31%). The aqueous extract of A. marmelos (100 µg/mL) demonstrated the highest larvicidal (57.33%) and pupicidal (42.67%) activities compared to other solvent extracts. In contrast, Am-ZnO-NPs exhibited relatively higher larvicidal activity (86.67%) and pupicidal (56.00%) at 10 µg/mL. The nanoparticles also inhibited the activities of acetylcholinesterase (AChE) and carboxylesterases and reduced the total protein (TP) levels in Ae. aegypti larvae. Further, both the aqueous leaf extract and Am-ZnO-NPs were effective in scavenging DPPH free radicals, achieving 76% and 94% inhibition, respectively, at a concentration of 125 µg/mL. Am-ZnO-NPs also exhibited cytotoxicity, induced cell cycle arrest, enhanced cell adhesion, and promoted apoptosis in L-132 lung cancer cell lines. Further, the Am-ZnO-NPs display potent antibacterial activity against clinical pathogens. These results highlight the role of phytochemicals in A. marmelos leaves for their effective biological activities.