Antimicrobial and cytotoxicity evaluation of Annona muricata-based silver-cobalt nanoparticles on WEHI 164 cell line

The harsh chemicals in conventionally fabricated metal nanoparticles have limited their applications for biomedical purposes. As part of green and sustainable chemistry in this study, an aqueous extract of indigenous Annona muricata was a reductant in preparing silver‑cobalt nanoparticles (AgCo NPs) for therapeutic application. The reaction progress and rate of formation of nanoparticles were monitored with a UV–visible spectrophotometer. The functional groups, structural morphology, and elemental composition of the AgCo NPs were confirmed using FTIR, SEM, TEM, and EDX techniques, respectively. This study evaluated the cytotoxicity potential of 21.38$\pm 8.0nm$ AgCo NPs on the WEHI 164 cell line for the first time, using an MTT assay and the antimicrobial potential of AgCo NPs against six microorganisms. The characteristic wavelength of absorption was observed between 400 and 450 nm. The antimicrobial test showed evident growth inhibition by AgCo NPs on P. aeruginosa, Candida albicans and Aspergillus niger. The in vitro cytotoxicity evaluation on the WEHI 164 cell line indicated that the AgCo NPs were cytotoxic at an IC₅₀ dosage of 84 μg/mL, and the cytotoxic potential was concentration-dependent. Hence, the Annona muricata synthesised AgCo NPs are potential pharmaceutical drug candidates.