Agave americana leaf extract-mediated green synthesis of silver nanoparticles: physicochemical characterization, antibacterial activity, antioxidant capacity, and cytotoxicity toward SiHa cells
This study reports a green and efficient route for the phyto-fabrication of silver nanoparticles using Agave americana leaf extract as both reducing and capping agent. The biosynthesis was completed under mild conditions, producing predominantly spherical nanoparticles with an average particle size of 57 ± 32.7 nm, a crystallite size of 19 nm, a surface plasmon resonance peak at 434 nm, and a zeta potential of -32.4 mV, indicating good colloidal stability. X-ray diffraction confirmed face-centered cubic silver, while Fourier transform infrared spectroscopy suggested the involvement of proteins and polysaccharides in nanoparticle stabilization. Thermal analysis showed an endothermic event at 103.88 °C, demonstrating a robust biogenic corona around the silver core. The nanoparticles exhibited strong antibacterial activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, with minimum inhibitory concentrations of 6.0, 5.0, and 3.0 µg mL-1, respectively. In addition, they showed antioxidant activity with 84.2% radical scavenging at 100 µg mL-1 and dose-dependent cytotoxicity against SiHa cervical cancer cells with a half-maximal inhibitory concentration of 15 µg mL-1. These findings suggest that Agave americana-derived silver nanoparticles are promising multifunctional nanomaterials for antimicrobial and anticancer applications, although further mechanistic and in vivo studies are required to confirm their biomedical potential.