Oxidative stress contributes to coffee constituent toxicity in SH-SY5Y neuroblastoma cells

Coffee is a widely consumed beverage that has been shown to have numerous health benefits including positive effects on neurological and psychological conditions including depression. Although positive benefits have been observed, some epidemiological studies have shown that with high consumption of caffeinated coffee, the risk of suicide increases significantly. Therefore, the aim of this study was to investigate the toxicity of key coffee constituents in in vitro neuronal models. The viability of SH-SY5Y neuroblastoma cells was evaluated after 24 h treatment with a range of concentrations (10 µM, 100 µM, and 1000 µM) of caffeine, caffeic acid (CA), chlorogenic acid (CGA), ferulic acid, pyrogallic acid (PA), and trigonelline. Furthermore, specific cell death pathways were investigated for their role in coffee constituent-induced toxicity. It was found that high concentrations (1000 μM) of CA, CGA, and PA were toxic toward undifferentiated SH-SY5Y neuroblastoma cells and caffeine, CA, CGA, and PA toward dibutyryl cyclic AMP differentiated SH-SY5Y neuroblastoma. After mechanisms were investigated cytotoxicity appeared to be due to reactive oxygen species (ROS)-induced apoptosis. This study has shown that high concentrations (1000 μM) of key constituents of coffee were toxic toward both undifferentiated and dibutyryl cyclic AMP differentiated SH-SY5Y cells.