Raman Spectroscopy and Imaging Reveal the Effect of β-Carotene Supplementation on Brain Cancer Cells

Dietary β-carotene is the most common carotenoid in the world. Naturally occurs in vegetables and fruits (e.g., carrots, tomatoes). Recently, β-carotene has been studied for its effects on the human body; however, the effect of this carotenoid on brain tumor metabolism at the cellular level is still unknown. Here, we consider whether β-carotene influences brain tumor cell metabolism and, if so, whether this effect stimulates or inhibits tumor growth. To find out the effect of β-carotene on brain cells (normal human astrocytes, astrocytoma, and glioblastoma), we applied Raman spectroscopy and imaging. We focused our analysis on biological changes in particular cell organelles such as the nucleus, mitochondria, lipid droplets/endoplasmic reticulum, and cytoplasm. Our Raman results demonstrated that cancer cell metabolism is altered following β-carotene supplementation, as reflected in changes to Raman bands associated with cytochrome c (1310 and 1583 cm^-1), lipids (1337 and 1444 cm^-1), and proteins (1337 and 1654 cm^-1). The response to supplementation is different not only for normal cells compared to cancer cells (the effects vary depending on the cell type) but also for supplementation timing and doses.