Biosynthesis and characterization of silver nanoparticles from Cedrela toona leaf extracts: An exploration into their antibacterial, anticancer, and antioxidant potential

This research work aims to synthesize environmentally benign and cost-effective metal nanoparticles. In this current research scenario, the leaf extract of Cedrela toona was used as a reducing agent to biosynthesize silver nanoparticles (AgNPs). The synthesis of AgNPs was confirmed by the color shift of the reaction mixture, i.e., silver nitrate and plant extract, from yellow to dark brown colloidal suspension and was established by UV-visible analysis showing a surface plasmon resonance band at 434 nm. Different experimental factors were optimized for the formation and stability of AgNPs, and the optimum conditions were found to be 1 mM AgNO3 concentration, a 1:9 ratio of extract/precursor, and an incubation temperature of 70°C for 4 h. The Fourier transform infrared spectroscopy spectra indicated the presence of phytochemicals in the leaf extract that played the role of bioreducing agents in forming AgNPs. X-ray diffraction patterns confirmed the presence of AgNPs with a mean size of 25.9 nm. The size distribution and morphology of AgNPs were investigated by scanning electron microscopy, which clearly highlighted spherical nanoparticles with a size distribution of 22–30 nm with a mean average size of 25.5 nm. Moreover, prominent antibacterial activity was found against Enterococcus faecalis (21 ± 0.5 mm), Bacillus subtilis (20 ± 0.9 mm), Pseudomonas aeruginosa (18 ± 0.3 mm), Staphylococcus aureus (16 ± 0.7 mm), Klebsiella pneumoniae (16 ± 0.3 mm), and Escherichia coli (14 ± 0.7 mm). In addition, antioxidant activity was determined by DPPH and ABTS assays. Higher antioxidant activity was reported in AgNPs compared to the plant extract in both DPPH (IC50 = 69.62 µg·ml−1) and ABTS assays (IC50 = 47.90 µg·ml−1). Furthermore, cytotoxic activity was also investigated by the MTT assay against MCF-7 cells, and IC50 was found to be 32.55 ± 0.05 µg·ml−1. The crux of this research is that AgNPs synthesized from the Cedrela toona leaf extract could be employed as antibacterial, antioxidant, and anticancer agents for the treatment of bacterial, free radical-oriented, and cancerous diseases.