Abstract
Colorectal cancer (CRC) is a major medical problem worldwide. Incidence is high in Western countries. However, it is now rapidly increasing in economic developing countries adapting the Western lifestyle. The increase in CRC cases and the drawbacks associated with existing treatment options led to the search for new compounds that can improve the effectiveness of current cancer therapies. The use of nanotechnology has been shown to reduce the toxicity of chemotherapies. Gold nanoparticles (AuNPs) have shown their capability to resolve several drawbacks associated with current chemotherapies, including lack of targeting, nonspecific biodistribution, and low therapeutic indices. They are among the most studied nanomaterials to discover and develop new improved cancer therapies. This study proposed a novel method to synthesize AuNPs using Vitellaria paradoxa leaf extract. In addition to, their antioxidant potential and inhibitory effects on the proliferation of human colorectal adenocarcinoma cells (HT-29) were investigated. The synthesized AuNPs were characterized using various analytical techniques. Ultraviolet-visible spectrum of AuNPs showed a peak absorption at 540 nm. Morphology and particle size analysis by transmission electron microscopy revealed polydisperse, spherical AuNPs with an average size of 27.13 nm. Dynamic light scattering also revealed the polydisperse nature of the nanoparticles and their stability with a surface charge of - 30.8 mV. Fourier transform infrared spectroscopy revealed the presence of hydroxyl, carboxylates, and amide functional groups on the surface of the AuNPs. The 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay was used to determine the antioxidant activity. The antiproliferative effect was evaluated using 3-(4,5-dimethylthiazol-2-yl)- 2,5 diphenyltetrazolium bromide (MTT) assay. The results revealed that Vitellaria paradoxa reduced AuNPs possess low (IC50 ˃ 1000 μg/ml) antioxidant properties, and moderate (IC50 = 188.77 μg/ml) cytotoxicity effect against HT-29 cells. Therefore, it can be concluded that Vitellaria paradoxa synthesized AuNPs may find application in the synthesis of anticancer drugs in the future.
M.Sc. (Nanoscience)