Synthesis of SnO ₂ Nanoparticles using <i>Brassica juncea</i> (L.) Czern Seed Extract: Characterization and Biological Applications

Abstract The green production of nanoparticles utilizing plants has emerged as a viable alternative to traditional chemical synthesis methods. This work sought to synthesize tin oxide nanoparticles (BJ‐SnO 2 NPs) using Brassica juncea (L.) Czern seed extract. The structure of BJ‐SnO 2 NPs was confirmed by X‐Ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis was conducted to identify the functional groups. The size and morphology of the synthesized BJ‐SnO 2 NPs were confirmed by field emission scanning electron microscopy (FE‐SEM) with energy dispersive X‐ray spectroscopy (EDS) and transmission electron microscopy (TEM). The TEM revealed the formation of spherical morphology with a mean diameter of 6.67 ± 1.72 nm. Dynamic Light Scattering (DLS) studies supported the average particle size as 8.9 nm and zeta potential showed a single peak at −40.1 mV. Free radical scavenging activity was determined using 2,2‐diphenyl‐1‐picryl‐hydazyl‐hydrate (DPPH) and showed IC 50 value as 82.25 µg/mL. The cytotoxic efficacy of BJ‐SnO 2 NPs was assessed against the Michigan Cancer Foundation‐7 (MCF‐7) breast cell line and A549 lung cancer cell line, which exhibited the IC 50 value as 64.10 and 48.68 µg/mL respectively, while demonstrated no harmful effects on normal Vero cell lines, which maintain 93.75% vitality. Additionally, a hyperchromic shift in the absorbance was noted when Calf thymus DNA (CT‐DNA) interacted with biosynthesized BJ‐SnO 2 NPs. In addition, the anti‐inflammatory effects of BJ‐SnO 2 NPs were evaluated using an in vitro model that used bovine serum albumin (BSA) denaturation method (IC 50 199.63 µg/mL). Overall, BJ‐SnO 2 NPs synthesized through biosynthesis route proved to be excellent anticancer, anti‐inflammatory, antioxidant, and biocompatible material with promising applications in healthcare.