Sustainable production of silver chloride nanoparticles from desert flora for biomedical applications with multifunctional biological activities

In this work, Euphorbia sanctae-catharinae leaf extract is used for the first time to biosynthesize silver chloride nanoparticles (AgCl-NPs) via a green synthesis approach. The formation and properties of the AgCl-NPs were confirmed using various characterization techniques: UV-Vis spectroscopy showed a characteristic absorption peak at 430 nm, indicating nanoparticle formation; X-ray diffraction (XRD) analysis revealed a crystallite size of approximately 24 nm; transmission electron microscopy (TEM) showed predominantly spherical nanoparticles with sizes ranging from 20 to 50 nm; and Fourier-transform infrared spectroscopy (FTIR) identified functional groups from the plant extract involved in nanoparticle stabilization. The MIC values were 62.5 µg/mL for (S. aureus, E. coli, E. faecalis, S. faecalis, E. aerogenes), 250 µg/mL for (S. epidermidis, K. pneumoniae, R. ornithinolytica), and 125 µg/mL for P. aeruginosa. The MBC values were 500 µg/mL for (R. ornithinolytica, S. faecalis, K. pneumoniae, S. epidermidis), and 250 µg/mL for (S. aureus, E. coli, E. faecalis), and 125 µg/mL for E. aerogenes. Tetracycline's synergistic actions increased antibacterial effectiveness by 21.4-47%. Furthermore, at a non-toxic dose (MNTC: 31.25 µg/mL), AgCl-NPs showed strong antiviral activity against HSV-1, preventing viral multiplication by 74%. These results demonstrate the potential of AgCl-NPs produced from Euphorbia sanctae-catharinae as a sustainable substitute for fighting viral infections and antibiotic resistance.