Antileishmanial and Antibacterial Potential of Biosynthesized Silver Nanoparticles using Carica papaya Leaves Extract

The utilization of plant extracts is preferred for the preparation of metal nanoparticles (NPs) due to biologically active components. We have recently reported the antioxidant, anti-inflammatory, and antileishmanial activities of silver nanoparticles synthesised from Phyllanthus emblica leaves. The main aim of this work was to examine a sustainable method for producing silver nanoparticles by utilising Carica papaya (papaya) leaf extract as a reducer. The fabricated AgNPs were characterized by UV-visible spectroscopy, Fourier transform infrared (FTIR), dynamic light scattering (DLS), and scanning electron microscopy (SEM). UV-Vis spectra of AgNPs have absorption maxima at 460 nm. FTIR bands identify the functional groups of the suspension that ensure the resilience of AgNPs. DLS measured the size of the formed AgNPs i.e. 68.40 nm. The zeta potential analyzer (ZP) of AgNPs exhibits values of -28.7 mV. The SEM results indicated the spherical as well as cuboidal shape of synthesized NPs with a mean size of 15 nm. Furthermore, the synthesized AgNPs showed putative antimicrobial activity towards various Gram-positive (+) and Gram-negative (-) pathogens and also anti-leishmanial activity. The IC50 content of AgNPs on L. donovani after 24, 48, and 72 h was calculated to be 45.88, 36.86, and 24.81 µg/mL, respectively. Moreover, this study confirmed anti-leishmanial and antibacterial properties in the AgNPs to further investigate the biomedical applications. The findings of this research present novel opportunities for the utilisation of green synthesized NPs derived in several domains such as pharmaceuticals and nanomedicine.