Zinc oxide nanoparticles using plant Lawsonia inermis and their mosquitocidal, antimicrobial, anticancer applications showing moderate side effects.

Microbes or parasites spread vector-borne diseases by mosquitoes without being affected themselves. Insecticides used in vector control produce a substantial problem for human health. This study synthesized zinc oxide nanoparticles (ZnO NPs) using Lawsonia inermis L. and were characterized by UV-vis, FT-IR, SEM with EDX, and XRD analysis. Green synthesized ZnO NPs were highly toxic against Anopheles stephensi, whose lethal concentrations values ranged from 5.494 ppm (I instar), 6.801 ppm (II instar), 9.336 ppm (III instar), 10.736 ppm (IV instar), and 12.710 ppm (pupae) in contrast to L. inermis treatment. The predation efficiency of the teleost fish Gambusia affinis and the copepod Mesocyclops aspericornis against A. stephensi was not affected by exposure at sublethal doses of ZnO NPs. The predatory potency for G. affinis was 45 (I) and 25.83% (IV), copepod M. aspericornis was 40.66 (I) and 10.8% (IV) while in an ZnO NPs contaminated environment, the predation by the fish G. affinis was boosted to 71.33 and 34.25%, and predation of the copepod M. aspericornis was 60.35 and 16.75%, respectively. ZnO NPs inhibited the growth of several microbial pathogens including the bacteria (Escherichia coli and Bacillus subtilis) and the fungi (Alternaria alternate and Aspergillus flavus), respectively. ZnO NPs decreased the cell viability of Hep-G2 with IC ₅₀ value of 21.63 µg/mL (R ²  = 0.942; P < 0.001) while the concentration increased from 1.88 to 30 µg/mL. These outcomes support the use of L. inermis mediated ZnO NPs for mosquito control and drug development.