IntroductionOne of the simplest nanostructures that is widely used in industry today is metallic nanoparticles. Metallic nanoparticles can bind non-destructively to single-stranded DNA, which are important in medical diagnostics. Cancer nanotechnology developed a new area of integrative research in biology, chemistry, engineering, and medicine, and is concerned with major advances in cancer diagnosis, prevention and treatment Material and methods In the recent study, the structural and morphological characterization of bio‐synthesized FeNPs@Calendula arvensis was performed by FT-IR and UV-vis spectroscopy, scanning electron microscopy (SEM) that SEM images have exhibited an equal and uniform spherical morphology in size of 30.13 nm. ResultsIn the antioxidant test, the IC50 of FeNPs@Calendula arvensis and BHT against DPPH free radicals were 117 and 88 µg/mL, respectively. In the anticancer test, the treated cells with FeNPs@Calendula arvensis were assessed by MTT assay for 48h about the anti-human cholangiocarcinoma and cytotoxicity properties on normal (HUVEC) and cholangiocarcinoma carcinoma cell lines i.e., HCM-CSHL-0174-C22, CCLP-1, and QBC939. The IC50 of FeNPs@Calendula arvensis were 196, 237, and 278 µg/mL against HCM-CSHL-0174-C22, CCLP-1, and QBC939 cell lines, respectively. The viability of cholangiocarcinoma cell line reduced dose-dependently in the presence of FeNPs@Calendula arvensis.ConclusionsIt appears that the anti-human cholangiocarcinoma effect of FeNPs@Calendula arvensis is due to their antioxidant effects.