Green Phytosynthesis of Silver Nanoparticles Using Echinochloa stagnina Extract with Reference to Their Antibacterial, Cytotoxic, and Larvicidal Activities

Herein, we report a novel green phytosynthesis for silver nanoparticles (AgNPs) using Echinochloa stagnina (Retz.) P. Beauv. (Burgu) extract and assess their potential activities. The phytosynthesized AgNPs were characterized using UV-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Fourier transform infrared (FTIR) spectroscopy. The surface plasmon resonance was peaked at 405 nm indicating the formation of AgNPs. Morphologically, AgNPs were spherical in shape with a diameter of 30 nm and monodispersed. Structurally, XRD data indicated that AgNPs were highly nanocrystalline in nature. FTIR spectral analysis demonstrated the presence of phytochemicals which could be responsible for the reduction of Ag ions and capping of AgNPs. The phytosynthesized AgNPs showed antibacterial activity with MIC of 12.5 and 6.25 mu g/mL against multidrug-resistant (MDR) Klebsiella oxytoca (ATCC 51983) and Pseudomonas aeruginosa (ATCC MP-23), respectively. The time-kill kinetics profile of AgNPs against MDR Klebsiella oxytoca (ATCC 51983) and Pseudomonas aeruginosa (ATCC MP-23) revealed a time- and dose-dependent reduction manner. The inhibition concentrations of AgNPs that inhibits 50% (IC50) of Vero and HepG2 cells were 89.01 and 35.1 mu g/mL, respectively. The LC50 and LC90 concentrations were (87.669 and 538.017 mg/mL) for Anopheles pharoensis and (51.338 and 311.227 mg/mL) for Culex pipiens, respectively. Collectively, our data suggest that plant-mediated synthesis of AgNPs is more feasible to synthesis AgNPs with improved properties.

Automated summary

A novel green phytosynthesis method using Echinochloa stagnina extract to synthesize silver nanoparticles (AgNPs) was reported, showing antibacterial activity and potential cytotoxic effects on various cells and insects. AgNPs were spherical in shape with a diameter of 30 nm, and exhibited inhibitory activity against multidrug-resistant bacteria. The study suggests that plant-mediated synthesis of AgNPs could be a feasible and effective method to produce AgNPs with improved properties.