Swift fabrication of Ag nanostructures using a colloidal solution of Holostemma ada-kodien (Apocynaceae) – Antibiofilm potential, insecticidal activity against mosquitoes and non-target impact on water bugs

• Published in: Journal of photochemistry and photobiology. B, Biology Biology, 2018-04, Vol.181, p.70-79
• Main Authors: Alyahya, Sami A., Govindarajan, Marimuthu, Alharbi, Naiyf S., Kadaikunnan, Shine, Khaled, Jamal M., Mothana, Ramzi A., Al-anbr, Mohammed N., Vaseeharan, Baskaralingam, Ishwarya, Ramachandran, Yazhiniprabha, Mariappan, Benelli, Giovanni
• Format: Article
• Language: English
• Subjects: Antimicrobial activity; Antimicrobial agents; Antimicrobial drugs; Aquatic insects; Biofilms; Confocal microscopy; Culicidae; Dengue; Dengue fever; Disease transmission; Dispersion; Energy transmission; Entomology; Fabrication; Fourier transforms; Gram-negative bacteria; Infrared spectroscopy; Insecticides; Larvae; Leaves; Malaria; Microorganisms; Mosquitoes; Nanomaterials; Nanoparticles; Nanostructure; Nanostructured materials; Nanotechnology; Non-target toxicity; Parasitic diseases; Proteus vulgaris; Pseudomonas aeruginosa; Scanning electron microscopy; Scanning microscopy; SEM; Silver; Spectroscopy; Synthesis; TEM; Toxicity; Transmission electron microscopy; Vectors; X-ray diffraction; XRD; Zika virus
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2018.02.019

Recent research in entomology and parasitology focused on the efficacy of green fabricated nanomaterials as novel insecticides. In this study, we synthesized poly-dispersed and stable silver nanoparticles (AgNPs) using the leaf extract of Holostemma ada-kodien. The nanostructures were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray, and X-ray diffraction analysis. The efficacy of H. ada-kodien leaf extract and AgNPs in vector control was evaluated against the mosquitoes Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, which act as major vectors of important parasitic and arboviral diseases. AgNPs showed higher toxicity if compared to the H. ada-kodien leaf aqueous extract, LC50 towards larvae of A. stephensi, A. aegypti, and C. quinquefasciatus were 12.18, 13.30, and 14.70 μg/mL, respectively. When the AgNPs were tested on non-target water bugs, Diplonychus indicus, the LC50 value was 623.48 μg/mL. Furthermore, 100 μl/mL of AgNPs achieved significant antimicrobial activity against Bacillus pumilus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus vulgaris, and Candida albicans. Light and confocal laser scanning microscopy highlighted a major impact of the H. ada-kodien-synthesized AgNPs on the external topography and architecture of microbial biofilms, both on Gram-positive and Gram-negative bacteria. Overall, this study sheds light on the insecticidal and antibiofilm potential of H. ada-kodien-synthesized AgNPs, a potential green resource for the rapid synthesis of polydispersed and highly stable AgNPs. [Display omitted] •The eco-friendly management of malaria and arbovirus vectors is a priority.•Ag nanoparticles (AgNPs) were synthesized using the Holostemma ada-kodien aqueous extract.•AgNPs were characterized by UV–visible spectroscopy, FTIR, SEM, HR-TEM, EDX and XRD.•AgNPs showed larvicidal activity on 3 mosquito vectors (LC50 12–14 μg/mL), and little toxicity on water bugs.•AgNPs inhibited growth and had antibiofilm activity on selected microbial pathogens.