Eco-Friendly Biosynthesis of Anti-Mycobacterium Silver Nanoparticles Using Ficus Ingens for Potential use in Tuberculosis and Leprosy

Abstract

Treatment of Mycobacterium infections including tuberculosis (TB) and leprosy continue to face challenges from drug resistant mycobacterium and bacterial strains. This has hampered efforts to contain the   pandemic due to rampant treatment failures based on current drugs. Therefore it is imperative to develop novel therapeutics. This study explored the Biosynthesis of silver nanoparticles (AgNPs) using Ficus ingens root extract, evaluating their antimicrobial activity. Ficus ingens, a large evergreen prevalent in sub-Saharan Africa has been widely used in TB treatments in traditional medicine in Zimbabwe. Preliminary phytochemical screening of the lyophilized root extract was done using various classical techniques, Oral toxicity evaluations were conducted based on OECD technical guideline 425.The anti-microbial tests were conducted using agar-well diffusion methods on Mycobacterium smegmatis as well Escherichia coli, and Staphylococcus aureus. with Rifampin ® as a standard. The bio inspired silver nanoparticles were fabricated through green synthesis techniques and characterized using UV, TEM and DLS, The Metabolomics studies confirmed the presence of numerous pharmacologically active secondary metabolites including  flavonoids, tannins, and phenols. Acute oral toxicity studies determined the LD50 of the lyophilised Ficus ingens root extract to be toxicologically safe above 4000mg/kg body weight.  UV-Vis confirmed the formation of the silver nanoparticles, Transmission electron microscopy and dynamic light scattering confirmed the AgNPs to have an average size of 38 nm, with various shapes including spherical and cubic morphologies. Antimicrobial assays demonstrated that the F. ingens extract and the AgNPs exhibited activity against Mycobacterium smegmatis, Escherichia coli, and Staphylococcus aureus comparable to the standard. Based on the foregoing, it was concluded that the biosynthesis of AgNPs mediated by F. ingens was feasible, efficacious, safe and presents a potential adjunct treatment for mycobacterium treatments in neglected tropical diseases.