Biosynthesized ZnO nanoparticles potentiate cytotoxicity: in vitro and in silico analysis

Abstract

Medicinal plants have been used in traditional practices such as the treatment of diarrhea, fertility, cancer, fungal infections, bronchitis, and microbial infections since prehistoric times. Indian medicinal plant Lantana camara (LC) exhibits anticancerous and antioxidant traits. Biocompatible zinc oxide nanoparticles (ZnO NPs) show great potential for cytotoxicity against mammalian cells. In the current report, ZnO NPs were prepared with Lantana camara leaf extract (LCLE) via a cost-effective and environmentally benign approach. The structural and optical properties of the biosynthesized ZnO NPs were characterized using XRD, FTIR, and UV-Vis spectroscopy. ZnO NPs exhibited a hexagonal wurtzite structure, a characteristic absorption peak at 374 nm with a band gap of 3.46 eV, and an average particle size of 22 nm. The cytotoxic activity of LCLE-mediated ZnO NPs was carried out against breast cancer cell lines MCF-7, and a dose-dependent decreasing trend was observed with an IC₅₀ value of 29.53 μg mL⁻¹. At the molecular level, structural similarities and differences for targets such as tyrosine protein kinase C-SRC, ERBB2 epidermal growth factor, HER2, human oestrogen receptor, and HSP90 proteins were identified and categorised with the aid of an in silico docking approach. Molecular docking is the most widely used of the several computational methods for assessing the anticancer potential of drugs. Thus, a selection of cancer receptors for quercetin, digoxin, morphine, and chrysophanic acid were subjected to in silico molecular docking studies. The combined and individual inhibitory effects of quercetin, digoxin, morphine, and chrysophanic acid were assessed against MCF-7 cells to evaluate their synergistic impact on cytotoxicity.