Raman micro-spectroscopy investigation on the effects of X-rays and polyphenols in human neuroblastoma cells

Raman micro-spectroscopy was used for an in vitro investigation aimed to elucidate the effects of X-rays and polyphenols derived from autochthonous sweet cherries from Campania (Italy) on specific sub-cellular regions of single SH-SY5Y human neuroblastoma cells. Nucleus and cytoplasm regions of single cells were investigated after the exposure to different doses of X-rays (0, 2, 4 Gy). Cells were fixed immediately after irradiation and/or after having been exposed to the cherry polyphenol extracts. Two different concentrations of polyphenol extracts (25 mu g/mL and 500 mu g/mL) with an exposure time of 48 h to polyphenols were considered. A deconvolution procedure using Lorentzian curves along with the evaluation of ratios between the intensity of selected peaks were used for analyzing the collected spectra in order to highlight the changes due to the different treatments. Biochemical changes occurring in nucleus and cytoplasm regions of single cells as a consequence X-ray irradiation were observed. In particular, the analysis of Raman spectra allowed us to detect modifications in the contribute from proteins, nucleic acids, lipids, and carbohydrates of cells, induced at different extent on the two cell regions. In fact, in the absence of polyphenols, the most relevant effects were observed in the cell nucleus region where modifications in the cell cycle were detected with an increase of DNA/RNA contribution, protein rearrangement and changes in lipids. The presence of the extracts induced changes in the observed variations. Our approach was also able to show the radiomodulating effects induced by the presence of different doses of polyphenols and different exposure times to these substances.