Investigation of health-related effects of phenolic acids and glycoalkaloids from Solanum tuberosum L. peel

Potato peel, sprout, and potato germplasm are characterized by a huge variety of bioactive compounds. Among these, the most interesting families of compounds are phenols/flavonoids (e.g. chlorogenic acid, caffeic acid and catechins), well-known antioxidants able to counteract oxidative stress and chronic degenerative diseases, and glycoalkaloids (e.g. α-chaconine and α-solanine), potent antitumor biocompounds. Exploring potato germoplasm, we profiled seven genotypes. At first, gene expression of genes playing pivotal roles in biosynthetic pathways of bioactive compounds was obtained from three cultivars (‘Bionica’, ‘Primura’ and ‘Kardal’), the advanced hybrid line Q115-6, three clones resulting from a cross between ‘Bionica’ and Q115-6 (ISCI181/10-3, ISCI181/10-4, ISCI201/10-1) by RT-PCR analysis. The results showed that hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) and cinnamate-4-hydroxylase (C4H) reflect chlorogenic and caffeic acid levels in the skin of all the genotypes (0.7 ≤ r ≤ 1.0). After that, potential cytotoxic effects of potato peels extracts and of standard molecules on two cancer cell lines compared to normal fibroblasts. Moreover, the extracts obtained with common hydroalcoholic/DMSO solvents were compared to extracts obtained with the green natural deep eutectic solvents (NaDES). Finally, the evaluation of a potential antitumor effects, the potential role of potato peels extracts in the protection of fibroblast against oxidative stress was assessed by means of spectrophotometric analysis and by monitoring the modulation of oxidative stress/antioxidant markers in the presence or absence of potato peel extracts by RT-PCR analyses. The synergistic effect of peel biocompounds requires a deeper investigation, however preliminary results are promising for the valorization of potato peel. Study Financed by the European Union - NextGenerationEU through the Italian Ministry of University and Research under PNRR - Mission 4, Component 1, Investment 4.1. (DM 118/2023)