Green synthesis and anti-tumor activity of curcumin @ ZnO/CuO nanoparticles

Both zinc oxide and copper oxide nanoparticles are promising biologically active materials. Green synthesis approach was used to prepare mixed ZnO/CuO nanoparticles loaded with curcumin extract. The isolated mixed oxides loaded with curcumin (curcumin @ ZnO/CuO) was characterized by UV–visible spectra, FTIR spectra, X-ray powder diffractions (XRD),Transmittance electron microscope (TEM), Energy dispersive x-ray (EDX) and x-ray photoelectron spectroscopy (XPS) spectra. X-ray powder diffractions indicated that ZnO has wurtzite structure and CuO crystallizes in a monoclinic system. XPS confirmed the existence of both CuO and ZnO nanoparticles. TEM results indicated the formation of quantum dots of curcumin @ ZnO/CuO with size in the range 6–10 nm. The optical band gaps of curcumin @ ZnO/CuO were determined and found to be 3.4 and 4.05 eV, which are higher than the bulk. The effects of curcumin @ ZnO/CuO on hepatocellular (HEPG-2) and colorectal (HCT-116) carcinoma were estimated by cell viability, cell cycle and anti-apoptotic factors (caspase-3/7, topoisomerase 2beta and annexin). Strong cytotoxicity activity and apoptosis of tumor cells were observed for curcumin @ ZnO/CuO. The cytotoxicity of the current compounds showed higher activity in comparison with other compounds that were previously studied.