Striga angustifolia mediated synthesis of silver nanoparticles: Anti-microbial, antioxidant and anti-proliferative activity in apoptotic p53 signalling pathway

Abstract In this study, silver nanoparticles synthesized from plant extract of Striga angustifolia were tested for antioxidant, anti-microbial and anti-cancer activities. To identify the compounds responsible for reduction of silver ions, the presence of bioactive metabolites in plant extract were investigated by FT-IR. The structural characterization of synthesized nanoparticles was demonstrated through UV, XRD, SEM and EDX, DLS and Zeta potential. The DPPH radical scavenging ability of the synthesized silver nanoparticles (AgNPs) showed significant results (IC50 values of 284.78 μg/mL), when compared to standard ascorbic acid (IC50 value = 191.29 μg/mL). Moreover, increasing concentration of nanoparticles exhibited enlarging zones of inhibition against the tested bacterial and fungal strains. The anti-proliferative ability on A549 lung cancer cell lines was determined by using the minimum inhibitory concentration of the AgNPs. The morphological changes revealed that the AgNPs is a potent candidate for drug delivery. Further, by cell cycle analysis using flowcytometry and gene expression analysis on p53 and p21, the particle proved to show anticancer activity by upregulation of the AgNPs induced target genes.