Green synthesis and chemical characterization of silver nanoparticles from aqueous extract of Falcaria vulgaris leaves and assessment of their cytotoxicity and antioxidant, antibacterial, antifungal and cutaneous wound healing properties

Nanotechnology encompasses the understanding of the fundamental physics, biology, chemistry and technology of nanometre-scale objects. In recent decades, nanotechnology has grown rapidly owing to its widespread application in science and industry. The aim of the work reported was the green synthesis and chemical characterization of silver nanoparticles from aqueous extract of Falcaria vulgaris leaves (AgNPs@Falcaria) and evaluation of their cytotoxicity and antioxidant, antibacterial, antifungal and cutaneous wound healing effects under in vitro and in vivo conditions. These nanoparticles were characterized using Fourier transform infrared and UV-visible spectroscopies, scanning and transmission electron microscopies and atomic force microscopy. 2,2-Diphenyl-1-picrylhydrazyl free radical scavenging experiments were conducted to evaluate the antioxidant potential, which indicated similar antioxidant potentials for AgNPs@Falcaria and butylated hydroxytoluene. The synthesized AgNPs@Falcaria had great cell viability dose-dependently, indicating their non-toxicity. Minimum inhibitory, minimum bactericidal and minimum fungicidal concentrations were determined by macro-broth dilution assay. The data were analysed using SPSS software (Duncan post hoc test). AgNPs@Falcaria revealed higher antibacterial and antifungal activities than many standard antibiotics (p <= 0.01). Also, AgNPs@Falcaria prevented the growth of all bacteria at 2-8 mg ml(-1) concentrations and removed them at 4-16 mg ml(-1) concentrations (p <= 0.01). AgNPs@Falcaria inhibited the growth of all fungi at 2-4 mg ml(-1) concentrations and destroyed them at 4-8 mg ml(-1) concentrations (p <= 0.01). For in vivo experiments, after creating a cutaneous wound, rats were randomly divided into six groups: untreated control, treatment with eucerin basal ointment, treatment with 3% tetracycline ointment, treatment with 0.2% AgNO3 ointment, treatment with 0.2% F. vulgaris ointment and treatment with 0.2% AgNPs@Falcaria ointment. Use of AgNPs@Falcaria ointment in the treatment groups substantially decreased (p <= 0.01) the wound area, total cells, neutrophils and lymphocytes and markedly raised (p <= 0.01) wound contracture, hydroxyproline, hexosamine, hexuronic acid, fibrocytes and fibrocyte/fibroblast ratio compared to the other groups. In summary, the synthesized AgNPs@Falcaria revealed non-cytotoxicity and antioxidant, antibacterial, antifungal and cutaneous wound healing activities in a dose-dependent manner.