Biosynthesis of silver nanoparticles from Hyphaene thebaica fruits and their in vitro pharmacognostic potential

Abstract

Hyphaene thebaica fruit extracts were applied as a low cost bio-reductant as well as capping agents for the biosynthesis of anisotropic silver nanoparticles (AgNPs). The AgNPs (4.5 nm–70 nm) revealed interesting morphologies and were characterized through diverse techniques. Characteristic Surface Plasmon Resonance (SPR) was observed at 411 nm which was stable in different physiochemical buffers suggesting excellent stability of silver. Zeta potential was recorded as −0.346 mV. X-ray Diffraction (XRD) pattern revealed formation of crystalline silver in pure phase also complemented by EDS (Energy Dispersive x-ray Spectroscopy). Fourier Transformed Infrared Spectroscopy (FTIR) indicated involvement of different phytochemicals as reducing and stabilizing agents. High Resolution-Transmission Electron Microscopy revealed interesting morphologies like spherical, rods, cubes etc. The multifunctional nanomedicinal application of AgNPs were assessed using different in vitro assays like antibacterial, antifungal, enzyme inhibition, antioxidant etc. AgNPs effectively inhibited bacterial strains of Bacillus subtilis, Pseudomonas aeruginosa and fungal strains of Aspergillus flavus and Mucor sp. Excellent DPPH radical scavenging (86%) is reported at 400 μg ml−1, while good total antioxidant capacity is observed. A dose dependant cytotoxicity is reported while blood compatibility at low doses is observed. AgNPs also revealed inhibition of protein kinase enzyme.