Infrared microspectroscopy studies on the protective effect of curcumin coated gold nanoparticles against H2O2-induced oxidative stress in human neuroblastoma SK-N-SH cells

Abstract

The contribution of oxidative stress in several chronic and degenerative diseases suggests that antioxidant therapy can be a promising therapeutic strategy. However, in the case of many antioxidants, their biodistribution and bioactivity are restricted due to low water solubility. Curcumin is a powerful free radical scavenger that upon conjugation to gold nanoparticles results in the formation of stable gold nanoparticles that act as highly water-soluble carriers for the curcumin molecules. In the present study, the effect of curcumin-coated gold nanoparticles (Cur-GNPs) on the H₂O₂-treated human neuroblastoma (SK-N-SH) cell line was evaluated by using Fourier transform infrared (FTIR) microspectroscopy. Biochemical changes in cells resulting from exposure to reactive oxygen species (ROS) and antioxidant treatment on cells were investigated. Analyzing changes in PO₂⁻ bands and amide bands in the fingerprint region and also changes in the ratio of CH_2(asym) to CH_3(asym) bands in the lipid region revealed that post-treatment with Cur-GNPs could effectively decrease the damage on DNA caused by H₂O₂ treatment, whereas pre-treatment of cells with Cur-GNPs was found to be more effective at preventing lipid peroxidation than post-treatment. Further analysis of the CH_2(asym) to CH_3(asym) ratio provided information on not only the lipid peroxidation level in cells, but also the interaction of nanoparticles with the plasma membrane, as confirmed by lactate dehydrogenase assay.