Characterization and Phenolic Profiling of Anticandidal <i>Polycladia myrica</i> and Its Mediated Iron Nanoparticles with the Evaluation of Their Antioxidant, Anti-Alzheimer, Catalytic Degradation, and Anticancer Activity via the P53 Pathway

As a potent reducing and capping agent, <i>Polycladia myrica</i> extract was used to create iron nanoparticles (FeNPs). UV-visible, Fourier transform infrared (FTIR), X-ray diffractive analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), zeta potential, hydrodynamic analysis with the determination of polydispersity index (PDI), and transmission electron microscopy (TEM) were used to characterize the produced iron nanoparticles. By examining the peak at 320 nm, UV-visible spectroscopy confirmed the production of PFeNPs. Additionally, various in vitro biological assays were conducted, demonstrating significant therapeutic potential. The cytotoxic assay was performed using lung carcinoma cells (A-549) and normal human lung fibroblast (MRC-5) cell lines, which demonstrated promising safe results with IC50 = 225.91 ± 8.93 μg/mL and CC50 = 488.80 ± 17.23 μg/mL, respectively, due to the forced apoptosis caused by the accumulation of both ROS and p53 levels inside cancer cells. PFeNPs demonstrated weak α-amylase inhibition with a percent of 33.96 ± 3.12 and potent acetylcholinesterase inhibition with a percent of 71.42 ± 3.64. The anticandidal activity of FeNPs biofabricated from <i>P. myrica</i> against <i>C. albicans</i> was estimated. The inhibition zone diameters of PFeNPs and Nystatin reference drug (mean ± SD) were about 18.82 ± 0.87 and 19.74 ± 0.98, respectively. MIC was determined to be about 500 and 312.5 μg/mL for both our algal FeNPs and the standard used drug, respectively. These results were confirmed by scanning electron microscopy, which revealed lysis and bursting of the exterior cell surface, along with deformation and death of <i>Candida albicans</i> cells in treated <i>Candida</i> isolate. These results strongly suggested the possibility of introducing PFeNPs as a cotherapy for <i>Candida</i> infections in diabetic cancer patients.