POLYPHENOLS FROM ANDEAN POTATO INDUCE CITOTOXICITY IN GLIOBLASTOMA CELLS BY MODIFYING THE REDOX STATUS

VAZQUEZ M; FILIBERTI V; ANDREU A. B.; SILVEYRA M.X.

Congreso; LXVI Reunion Anual de la Sociedad Argentina de Investigaciones Clinicas; 2021

Sociedad Argentina de Investigaciones Clinicas

Andean potatoes (Solanum tuberosum ssp. andigena) are a good source of dietary polyphenols, such as chlorogenic acid and anthocyanins. This study aimed to analyze the cytotoxic activity of polyphenols from Andean potato var. Santa María on glioblastoma cells. In order to test this, we first assayed the cell viability by incubating different concentrations of polyphenol extracts with human glioblastoma LN-229 cells. We observed that polyphenols induced changes in the morphology of the cells and reduced the viability in a concentration-dependent manner. Then, we calculated the CC50 (50% cytotoxic concentration) of total polyphenols extract and proceeded to investigate how the cells dye. First, we treated the cells with the CC50 for 4 hr and measured the intracellular reactive oxygen species (ROS) using the probe H2DCFDA. At the beginning of treatment, the ROS levels decreased compared to control, but after 2 hr, they increased, suggesting that the polyphenols altered the redox homeostasis in glioblastoma cells. To analyze what happens in the mitochondria, we determined the potential mitochondrial membrane with Rhodamine 123. After 3 hr of treatment, we observed a significant decrease, confirming that polyphenols would induce dysfunction in the mitochondria that contributes to increased ROS levels. Finally, we performed a DAPI staining of cells´ nuclei and visualized them with fluorescence microscopy, observing significant alterations in treated cells such as bright nuclear condensation and, in some cases, fragmented nucleus. However, we checked the genomic DNA fragmentation in agarose gel, and we determined that polyphenols produced a slight reduction in genomic DNA size with a lack of oligonucleosomal fragments, suggesting the activation of a mechanism of death caspase-independent. These findings demonstrated that polyphenols from Andean potato var. Santa María would be a good source of bioactive compounds with anti-glioblastoma activity that impacts human health.