Red-purple Andean potato polyphenols have an in vitro anti-neuroblastoma effect via mitochondrial dysfunction-induced apoptosis

Abstract

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 polyphenols from Santa María tuber activated programmed cell death by caspase-independent apoptosis. They induced cell morphology changes, including the nucleus, and slightly affected the cell cycle. Furthermore, tuber polyphenols altered redox homeostasis and mitochondrial function of neuroblastoma cells, which increased the number of apoptotic cells. We also showed that neither Bcl-2 nor caspase-3 was involved in this mechanism of death. In summary, our results demonstrated that polyphenols from Santa María tuber are bioactive compounds that have mitochondria as a target and contribute to revalorizing Andean potatoes as a functional food. These findings suggest that they would be a good source of anti-tumor compounds that could induce tumor cell death even in apoptotic-resistant tumors, opening new therapeutic avenues.