Biogenically proficient synthesis and characterization of silver nanoparticles (Ag-NPs) employing aqueous extract of Aquilegia pubiflora along with their in vitro antimicrobial, anti-cancer and other biological applications

Aquilegia pubiflora leaves are reported against hepatitis, for treatment of skin burns, wound healing, jaundice, gynea, circulatory and cardiovascular disease in several studies. Therefore, green synthesis of silver nanoparticles with A. pubiflora leaves extract, as an alternative to chemical synthesis, is beneficial from its biological applications point of view. The formation and size distribution of Ag-NPs were confirmed by UV-spectroscopy, Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Transmission electron microscopy (TEM), Energy Dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR) and HPLC. Silver nanoparticles with a particle size of 19 nm were used in various assays including antimicrobial, antioxidant, anti-Alzheimer, anti-diabetic, anti-aging, anti-cancer and biocompatibility studies. Our findings revealed that A. pubiflora mediated Ag-NPs were highly active against both bacterial and fungal strains with Escherichia coli and Aspergillus niger displaying the highest zone of inhibition 10.9 ± 0.29 mm and 13.11 ± 0.33 mm respectively. Dose dependent cytotoxic activity was shown by NPs against Leishmania Tropica with significant IC 50 of 175 μg/mL for promastigote and 169 μg/mL for amastigote forms. The Ag-NPs proved to be highly toxic for the HepG2 cell line and inhibit cell viability up to 52.06 ± 2.9% after 24 h of Ag-NPs treatment. Ag-NPs also showed excellent inhibitory potential against the enzymes acetylcholinesterase (AChE: 71.38 ± 1.75) and butyrylcholinesterase (BChE: 73.61 ± 1.96) which are involved in Alzheimer's disease. Overall, the enzymes involved in aging, diabetes, and inflammation showed a moderate inhibitory response to Ag-NPs, led to the conclusion that they are a promising choice for various biological applications.