CONICET | Buscador de Institutos y Recursos Humanos

Oxidative stress is associated with many pathologies going from cancer to neurodegenerative diseases, and antioxidants such as polyphenols have an impact on them. Potato peel waste (PPW) is the major leftover from the potato processing. We have previously demonstrated that the total level of phenolic compounds was up two to four times more in peel compared to flesh, which is correlated with a major antioxidant activity. The aim of this study was to characterize the phenolic composition and biological activities of antioxidant polyphenols from PPW in vitro. The HPLC-DAD analysis of PPW extracts indicated the presence of three isoforms of chlorogenic acid (CGA), 5-CGA, 4-CGA (cryptochlorogenic) and 3-CGA (neoclorogenic), being 5-CGA the major one. Caffeic acid was also detected, although as a minor component. The content of total phenols of PPW extract was 2650.00 ± 1092.26 μg eq. CGA.g-1 dry weight determined by the Folin-Ciocalteu method, and the antioxidant capacity was 2113.94 ± 1089.89 μg eq. Trolox.g-1 dry weight. In order to test the biological activities, we assayed different doses of PPW extract on a human neuroblastoma cell line or neuronal differentiated cells injured by hydrogen peroxide (H2O2) or amyloid peptide (Aβ25-35). First, we observed a dose-dependent cytotoxic effect on the human neuroblastoma cell line, where doses greater than 20 μg eq. CGA.mL-1 induced a significant decrease in the cell viability of the tumor cells (p=0,0063). Then, pretreatment with low doses of PPW extracts was observed to protect injured-H2O2 or Aβ25-35 neuronal differentiated cells. These findings demonstrated a dual effect of polyphenols from PPW, where the phenolic compounds quantity and the cellular physiology are important to induce different effects. Our results suggest that potato peel waste would be a good source of neuroprotective antioxidants polyphenols to development a dietary supplement with some impact in human health.