BIOGENIC ZINC OXIDE NANOPARTICLE FABRICATION USING KIGELIA PINNATA AQUEOUS LEAF EXTRACT AND ITS CHARACTERISATION, ANTIOXIDANT AND ANTICANCER EVALUATION

Abstract

Kigelia pinnata, commonly known as sausage tree, belongs to the Bignoniaceae family and is a medicinal plant rich in flavonoids, iridoids, and naphthoquinones. The present study deals with aqueous leaf extract to biofabricate zinc oxide nanoparticles (ZnO NPs). The synthesised nanoparticles were characterised for their morphology, size and properties using different analytical techniques like UV-Vis spectroscopy, XRD, FTIR, SEM-EDAX, HR TEM, DLS and Zeta potential. The synthesised nanoparticles were crystalline, ultra-small (4-8 nm by HR TEM) and moderately stable (-20.4 mV). They exhibited potent antioxidant activity with ABTS and DPPH IC50 values (4.49 and 4.81 µg/mL) comparable to ascorbic acid, and higher ferric-reducing efficiency (FRAP IC50 - 15.07 µg/mL). Photocatalytic assays confirmed effective methylene blue degradation (58.81 % in 180 min). Cytotoxicity tests showed selective anticancer activity, most potent against HCT-116 cells with an IC50 value of 39.39 µg/mL, including apoptosis, ROS generation, caspase-3 activation, and G2/M arrest. Overall, K. pinnata mediated ZnO NPs show promise as eco-friendly nanomaterials with biomedical and environmental applications.