Green Synthesized Bismuth Oxide Nanoparticles Using Aqueous Rhizome Extract of Curcuma longa Mitigate the Proliferation of Human U87 Glioblastoma Cells by Regulation of the Wnt/β-Catenin Signaling Pathway

The low biocompatibility of inorganic nanoparticles (NPs) is a main concern in their wide applications in the biomedical field. Therefore, the green synthesis of NPs from plant extracts can provide safe NPs for biomedical applications. The present study was aimed to assess the anticancer activity of bismuth oxide (Bi2O3) NPs fabricated using aqueous plant extracts from the rhizome of Curcuma longa (C. longa). Characterization of green Bi2O3 NPs was done using TEM, DLS, and X-ray diffraction analyses. Selective anticancer activity of green Bi2O3 NPs against human glioblastoma (U87) cells was assessed using MTT, GSH, MDA, ROS, apoptosis, and caspase-3 assays. Also, qPCR analysis was done to explore the expression of beta-catenin, cyclin D1, and c-myc at mRNA level as the important genes of the Wnt/beta-catenin signaling pathway. The results showed that the green Bi2O3 NPs have a crystalline nature with a size of around 30 nm with good colloidal stability attributed to potential bio-fabrication of Bi2O3 NPs. Cellular study indicated that green Bi2O3 NPs triggered selective anticancer activity against U87 cells through reduction of GSH level and increase of MDA level, ROS level, Annexin cells, and caspase-3 activity. Also, it was found that IC50 concentration of biosynthesized Bi2O3 NPs (20 mu g/mL) resulted in a significant downregulation in the expression of beta-catenin, cyclin D1, and c-myc genes involved in the Wnt/beta-catenin signaling pathway. This study concludes that green Bi2O3 NPs bio-fabricated from rhizome of C. longa show potential selective anticancer activity.