Investigating taurine's biochemical influence in human brain cancer cells with confocal Raman imaging

Given the widespread use of taurine in energy drinks and nutritional supplements, it is imperative to evaluate its effects on cell behavior and metabolic activity. Understanding the multifaceted cellular effects of taurine remains a significant challenge, particularly in the context of its metabolic and regulatory roles in cancer and stress-adapted cells. One of the limitations in this field has been the lack of imaging techniques capable of capturing taurine's molecular interactions and downstream biochemical alterations in living cells with adequate spatial and molecular specificity. In this study, we employ a Raman-based imaging approach to investigate the intracellular distribution and metabolic consequences of taurine treatment in human brain carcinoma cells (astrocytoma CCF-STTG1 line). This label-free technique enables real-time monitoring of biochemical changes in situ, revealing specific spectral shifts indicative of taurine's influence on energy metabolism, redox balance, lipid dynamics, and structural proteins. We observed marked alterations in Raman spectral bands at ∼750, ∼782, ∼1003, ∼1126, ∼1254, ∼1302, ∼1444, ∼1583, and ∼ 1654 cm^-1, which correspond to components such as cytochrome c, nucleic acids, phenylalanine, saturated lipid chains, and amide vibrations of proteins. Notably, the enhancement of cytochrome c signals (∼750 and ∼ 1583 cm^-1) suggests an upregulation of mitochondrial oxidative metabolism, while a concurrent attenuation in glycolytic markers (∼870 and ∼ 1450 cm^-1) supports a metabolic shift away from aerobic glycolysis. Our Raman spectroscopic findings provide a high-resolution biochemical fingerprint of taurine's intracellular action, offering crucial insights into its role in modulating tumor cell metabolism and potential mechanisms of therapy sensitization. This study contributes to a more precise understanding of taurine's bioactivity in a human brain carcinoma model and underscores the value of vibrational imaging in cellular pharmacology and metabolic research.