Untying the antimicrobial and antioxidant potential of silver nanoparticles fabricated from Typhonium trilobatum (L.) Schott

Abstract

Understanding the properties of silver nanoparticles (AgNPs) is noteworthy for the development of novel antimicrobial agents. Here AgNPs were procured through a sustainable, effortless, simple and lucrative process by using natural reducing agents from aqueous leaf extract of Typhonium trilobatum (L.) Schott. The study mainly aims at the determination of antibacterial and antioxidant activity of the bio-fabricated AgNPs. The synthesis of nanoparticles (NPs) was initially confirmed by UV–vis spectroscopy. The AgNPs were spherical with diameter ranges between 30 and 90 nm, negatively charged at −29.6 mV, crystalline in nature and surrounded by different active functional groups as evident by FTIR spectra analysis. The presence of phenolic compounds such as gallic acid and catechin were confirmed through HPLC analysis, providing insights into the bio-reduction mechanism which facilitate the conversion of Ag+ to AgNPs. Antimicrobial properties of the synthesized AgNPs were assessed against four Gram-negative and two Gram-positive bacteria with maximum zone of inhibition against Staphylococcus aureus (20±3.00 mm) and Micrococcus luteus (20±1.73 mm). The antibacterial potential of AgNPs is primarily linked with the increased cell membrane permeability of AgNPs treated bacterial cells (E. coli, S. aureus and M. luteus) as evident by measuring increased conductivity and elevated extracellular DNA concentration due to the disruption of bacterial cell membrane. Synthesized AgNPs exhibited antioxidant properties with IC₅₀ value of 239.50 mg/L in free radical scavenging activity and IC₅₀ value of 213.23 mg/L in superoxide scavenging activity. To the best of our knowledge, this is the earliest report of biosynthesis and physico-chemical characterization of AgNPs using T. trilobatum leaf extract having efficient antioxidant and antibacterial activity against some bacteria. These plant-mediated AgNPs might offer a promising solution in antibiotic resistance—a growing global health threat.