Induction of Apoptosis in MCF‐7 Breast Cancer Cells by Selenium Nanoparticles Synthesized With Laccase Enzyme Isolated From <i>Pleurotus Floridanus</i>

Abstract

ABSTRACT This study aimed to develop an eco‐friendly and efficient method for synthesizing selenium nanoparticles using purified laccase from Pleurotus floridanus . SeNPs were mycosynthesized at varying sodium selenite concentrations (5–20 mM). Dynamic light scattering analysis revealed particle sizes ranging from 30 to 80 nm, with a mean size of 54 nm and a polydispersity index of 0.843. SEM and HR‐TEM images showed predominantly spherical nanoparticles with an average size of 25 nm. Antibacterial assays demonstrated dose‐dependent inhibition against Pseudomonas aeruginosa , Escherichia coli , and Klebsiella pneumoniae , with the highest activity observed against P. aeruginosa at 20 mg/mL concentration. The antiproliferative effect on MCF‐7 breast cancer cells was also dose‐dependent, with an IC₅₀ of 222 μg/mL and up to 81.2% reduction in viability at 500 μg/mL. Western blot analysis showed marked upregulation of proapoptotic proteins Bax, Caspase 3, Caspase 9, and p53. These results highlight the potent antimicrobial and anticancer properties of SeNPs.