Characterization and Biological Activities of Silver Nanoparticles Synthesized using Grewia tiliifolia Vahl Leaf Extract

Background: An eco-friendly approach for the synthesis of noble metal nanoparticles employing various plant extracts has become of great interest in the field of nanotechnology. In the present study, the efficacy of Grewia tiliifolia leaf extract in reducing 1 mM silver nitrate to silver nanoparticles (AgNPs) has been reported for the first time. We also investigated the anticancer, antituberculosis and antioxidant activity.
Methods: Characterization of biosynthesized AgNPs using G. tiliifolia leaf extract was evaluated by different techniques. Efficacy of biosynthesized AgNPs using G. tiliifolia leaf extract was tested for cytotoxicity against A549 Lung cancer cell lines by MTT Assay and against the infectious agent Mycobacterium tuberculosis using MABA assay. Further antioxidant activity was evaluated by DPPH radical scavenging assay.
Results: The biosynthesis of AgNPs was evident by a color change of the reaction mixture from dark yellow to reddish-brown. Biofabricated AgNPs were further confirmed by characteristic surface plasmon absorption peak at 409 nm by UV-vis analysis. FTIR data reveals the presence of phytochemicals involved in bioreduction and biocapping of AgNPs, XRD analysis depicted the crystallographic nature of AgNPs. Further, size, charge, and polydispersity nature were studied using DLS (40.2 nm with polydispersity index 0.361) and Zeta potential (-35.8 mV). The morphology of AgNPs was determined by TEM analysis with a size ranging from 11-34 nm. The plant-derived AgNPs exhibited a cytotoxic effect on the lung cancer cell line with an IC50 value of 23.45 µg/ml and were also found to be effective against M. tuberculosis with a MIC of 6.25 µg/ml in comparison to the leaf extract (MIC 50 µg/ml). Antioxidant activity observed by AgNPs was moderate with IC50 value of 49.60 µg/ml.
Conclusion: The findings indicate that the AgNPs synthesized from leaf extract of G. tiliifolia are eco-friendly, cost-effective, non-toxic and can be effective natural anticancer, antituberculosis and antioxidant agents.