Beet leaves after in vitro human gastrointestinal digestion present antioxidant capacity and protective effects in colorectal cancer cells.

Beetroot (Beta vulgaris L.) is a highly nutritious vegetable. While the root is the most consumed part, the leaves, often discarded, are rich in nutrients and bioactive compounds such as phenolic compounds. These compounds have shown efficacy against cancer, including colorectal cancer, a leading cause of global morbidity and mortality. However, for these compounds to be effective, they must remain bioavailable and bioactive after gastrointestinal digestion. This study investigated beet leaves' antioxidant capacity and anticancer effects on the colorectal cancer cell line HCT116 after in vitro digestion. The digested beet leaf sample showed antioxidant capacity through in vitro tests (ORAC, ABTS, and DPPH) and also maintained DNA supercoil despite the presence of the oxidizing agent. There was a significant reduction in HCT116 cell's proliferation and colony formation, with the number and size of colonies decreasing after treatment with the digested material. Additionally, the digested material reduced the phosphorylation of S6, S6K1 and S6K2 proteins, which are important effectors in the mTOR pathway. Isolated apigenin significantly influenced S6 protein activity, and while it did not reduce the number of colonies, it decreased their size. Thus, this study confirms that beet greens retain their antioxidant capacity after gastrointestinal digestion and may have potential anticancer effects against colorectal cancer.