Due to their huge surface area to volume ratio, metallic nanoparticles are becoming increasingly important in numerous spheres of life. Here, initially, we aimed to evaluate the potential use of Cassia auriculata (CA) extract to synthesize silver nanoparticles (AgNPs). Then, we evaluated its antimicrobial potential and antioxidant capacity, as well as performed in silico analysis, and investigated the possible non-toxic effect of AgNPs on Artemia nauplii. Fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM/TEM), energy dispersive spectroscopy (EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS) studies were used to characterize the biosynthesized AgNPs. Our data indicate that Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus bacteria were susceptible to the biosynthesized AgNPs, whose effect was concentration-response. With a ZOI of 10 mm, the AgNPs were most efficient against gram-positive B. cereus bacteria at the highest concentration (75 μg/mL). The biosynthesized AgNPs (at 25 to 125 μg/mL) showed good antioxidant activity in the DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) and FRAP (ferric reducing antioxidant power) assays. Oleanolic acid from CA exhibited strong binding affinity and high binding energy to E. coli and B. cereus (-9.66 and - 9.74 kcal/mol) on in silico research. According to the comparative non-toxicity analysis, AgNPs, AgNO3, and CA bark extract had the least toxic effects on A. nauplii, with respective mortality rates of 28.14, 32.26, and 38.42 %, respectively. In conclusion, the current work showed that AgNPs produced from CA bark could be a promising material for diverse applications.
Keywords: AgNPs; Antibacterial; Antioxidant; Cassia auriculata; Green nanosynthesis; In silico; Non-toxic.
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