Structural, vibrational, optical, and anticancer properties of Hyphaene thebaica‐reduced nano‐lanthanum oxide (La2O3)

Abstract

Phytoextracts modulated synthesis of nano‐scaled spherical lanthanum oxide nanoparticles (La2O3 NPs) are reported using the aqueous extracts of Hyphaene thebaica as a bioreducing and chelating agent. X‐ray diffraction (XRD) pattern revealed sharp peaks and single‐phase purity. The Debye–Scherrer approximation indicated an average crystallite size of 37 nm, whereas W‐H plot revealed a crystallite size of 59 nm, complemented by the high‐resolution transmission electron microscopy (HR‐TEM). The infrared spectroscopy revealed characteristic La‐O band at 426 and 648 cm−1. K‐M function revealed the bandgap of 5.6 eV, whereas broad intense emission peaks between 345 and 750 nm. The Raman spectra revealed peaks at 182, 325, 384, and 491 cm−1. Elemental composition was confirmed using energy‐dispersive X‐ray spectroscopy (EDS) spectrum, and the spotty rings from selected area electron diffraction (SAED) indicated the crystalline nature of the HT‐La2O3 NPs. In addition, the HT‐La2O3 NPs were investigated for in vitro antioxidant, anticancer, antiangiogenic, and cytotoxic potentials. DPPH free radical scavenging activity was highest, that is, 49.54 ± 0.88% at 1000 μg/mL. MTT assay on MCF‐7 and 3T3 cell lines revealed a median lethal concentration of 114 and 43 μg/mL, respectively. The antiangiogenic effect examined by chick chorioallantoic membrane (CAM) assay indicated inhibition of 57.14 ± 0.96% at 1000‐μg/mL concentration with an IC50 of 551 μg/mL. IC50 for the brine shrimp lethality assay was 314.2 μg/mL. Our study indicates cytotoxicity of HT‐La2O3 NPs, and it further concluded that HT‐La2O3 NPs were more potent against 3T3 cells as compared with MCF‐7 cells. Further research on the biological synthesis and anticancer studies are recommended for the large‐scale applications of the La2O3 NPs.