Genotoxic and Cytotoxic Properties of Zinc Oxide Nanoparticles Phyto-Fabricated from the Obscure Morning Glory Plant <i>Ipomoea obscura</i> (L.) Ker Gawl

Abstract

The study was undertaken to investigate the antioxidant, genotoxic, and cytotoxic potentialities of phyto-fabricated zinc oxide nanoparticles (ZnO-NPs) from Ipomoea obscura (L.) Ker Gawl. aqueous leaf extract. The UV-visible spectral analysis of the ZnO-NPs showed an absorption peak at 304 nm with a bandgap energy of 3.54 eV, which are characteristics of zinc nanoparticles. Moreover, the particles were of nano-size (~24.26 nm) with 88.11% purity and were agglomerated as observed through Scanning Electron Microscopy (SEM). The phyto-fabricated ZnO-NPs offered radical scavenging activity (RSA) in a dose-dependent manner with an IC50 of 0.45 mg mL−1. In addition, the genotoxicity studies of ZnO-NPs carried out on onion root tips revealed that the particles were able to significantly inhibit the cell division at the mitotic stage with a mitotic index of 39.49%. Further, the cytotoxic studies on HT-29 cells showed that the phyto-fabricated ZnO-NPs could arrest the cell division as early as in the G0/G1 phase (with 92.14%) with 73.14% cells showing early apoptotic symptoms after 24 h of incubation. The results of the study affirm the ability of phyto-fabricated ZnO-NPs from aqueous leaf extract of I. obscura is beneficial in the cytotoxic application.

Keywords

• cytotoxicity
• genotoxicity
• cell cycle analysis by flow cytometry
• ZnO-NPs
• HT-29 cells
• <i>Allium cepa</i>