Biogenic Synthesis of AgNPs with Saussurea lappa C.B. Clarke and Studies on Their Biochemical Properties.

Nanotechnology has become an irreplaceable need and green synthesis of nanoparticles offers several advantages over physical and chemical methods. Medicinal plants are the main reservoirs of drugs and drug candidates. We report the biogenic synthesis of silver nanoparticles (AgNPs) using aqueous root extract of Saussurea lappa. Verification and characterization of these nanoparticles were done by UV-visible spectroscopy, XRD-analysis and Scanning Electron Microscopy and FT-IR. Extract-loaded-AgNPs showed the highest inhibition zone against Escherichia coli (11.0 mm) and intermediate against Pseudomonas aeruginosa (9.0 mm). The methanolic root extract of S. lappa alone, also moderately inhibited Pseudomonas aeruginosa (9.0 mm) and showed lower activity (6.0 mm) against Escherichia coli. Its aqueous roots extract inhibited (6.0 mm) the growth of tested organisms. Methanolic extract showed antioxidant potency (IC50 = 0.814 μg/mL). Experiments revealed the presence of phenols and flavonoids in the roots of Saussurea lappa. These findings provide promising interest to exploit Saussurea lappa for the biogenic synthesis of AgNPs and their biological applications.