Eco-friendly Synthesis of Zinc Oxide Nanoparticles by Clerodendrum heterophyllum Leaf Extract and Their Biological Applications

Clerodendrum heterophyllum, a member of the Lamiaceae family, has been traditionally used in herbal medicine. In this study, zinc oxide nanoparticles (ZnONPs) were synthesized, which led to a color change from greenish yellow to a pale white precipitate. The synthesized ZnONPs were then subjected to various characterization techniques including UV-visible spectrum, FTIR, XRD, SEM-EDAX, and TEM. The UV-visible spectrum analysis revealed a peak at 366 nm, indicating the presence of ZnONPs. FTIR analysis confirmed the presence of 15 different functional groups in the nanoparticles, while XRD results confirmed their crystalline structure. SEM analysis showed the formation of spherical-shaped nanoparticles, and EDAX analysis confirmed the elemental composition of zinc and oxygen. TEM results indicated that the size of the ZnONPs ranged between 4.68 and 8.65 nm. The antibacterial activities of the ZnONPs were evaluated against Staphylococcus aureus and Escherichia coli, showing high effectiveness with inhibition zones of 13 mm and 11 mm, respectively. The ZnONPs also exhibited antioxidant activity, as demonstrated by their capability to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid), and H2O2 (hydrogen peroxide radical) assay. Moreover, in HepG2 liver cancer cells, the ZnONPs showed maximum inhibitory effects at 66.86%. In conclusion, this research highlights the biological properties of C. heterophyllum, particularly its potential as a viable resource for the synthesis of ZnONPs.