Red-purple Andean potato polyphenols have an anti-neuroblastoma effect in vitro via apoptosis through mitochondria.

Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such as phenolic acid and flavonoids. These polyphenols have several beneficial effects on human health due to their antioxidant properties. Previously, we demonstrated that polyphenol extracts from Andean potato tubers exerted a concentration-dependent cytotoxic effect in human neuroblastoma cells. However, the mechanisms involved in this cytotoxic activity were not explored. Here we show that Santa Maria tubers polyphenols activated a programmed cell death by caspase-independent apoptosis. We found that polyphenols induced cell and nucleus morphology changes and slightly affected the cell cycle. Furthermore, the polyphenols altered the neuroblastoma cells homeostasis redox and mitochondrial function, increasing the levels of apoptotic cells. Finally, we showed that neither Bcl-2 nor caspase-3 was involved in this mechanism of death. Our results confirmed that Santa Maria tubers polyphenols are bioactive compounds with mitochondria as a target and contribute to revalorizing Andean potatoes as a functional food. These findings demonstrated that they would be a good source of anti-tumor compounds that would induce tumor cell death even in apoptotic-resistant tumors, opening new therapeutic avenues.