Plumeria pudica Jacq. flower extract - mediated silver nanoparticles: characterization and evaluation of biomedical applications

Abstract The green synthesized silver nanoparticles have gained attention due to their efficient biomedical applications. In the present study, the silver nanoparticles were synthesized using Plumeria pudica Jacq. flower extract (PP-AgNPs) and characterized by various spectroscopic techniques. Further, their antibacterial, free radicals scavenging, anticancer, larvicidal, anti-acetylcholinesterase, reusability and durability were also evaluated. UV–Visible spectrum displayed a peak at 434 nm, confirming the nanoparticle origination, and fourier transform infra-red spectrum confirmed the participation of biological components in nanoparticle synthesis. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, and energy dispersive x-ray spectroscopy displayed crystalline nature and spherical morphology, and elemental structure of the PP-AgNPs and the average particle size was found to be 27.1 nm. Antibacterial activity of PP-AgNPs showed the highest inhibition against E. coli (16.33 ± 0.14 mm) at 40 μL concentration. Free radical scavenging was done by 2,2-diphenyl-1-picrylhydrazyl, hydroxyl, superoxide and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) assays, and the inhibitory concentration (IC50) was found to be 30.4, 32.5, 30 and 18 μg/mL, respectively. PP-AgNPs showed significant cytotoxicity against HepG2 cell line in a dose-dependent manner with IC50 value of 62.07 µg/mL and induced ROS production and apoptosis in a time-dependent manner. A significant larvicidal activity of PP-AgNPs was found against Culex quinquefasciatus with IC50 value of 0.79 µg/mL and also PP-AgNPs inhibited the production of acetylcholinesterase. PP-AgNPs were reused and durable in photocatalytic degradation up to four runs. Based on our findings, PP-AgNPs evinced biomedical resources and can be conceivably used for the development of a drug and mosquito control.