Gastrointestinal digested Sambucus nigra L. fruit extract protects in vitro cultured human colon cells against oxidative stress

• Gastrointestinal digestion causes a significant loss of elderberry biocompounds.
• Elderberry fruit extract retains antioxidant activity following colon digestion.
• Elderberry extract decreases ROS production in in vitro cultured human colon cells.
• Extract of elderberries decreases oxidative DNA damage in the cells of colon mucosa.
• Elderberry fruit extract inhibits mutagenesis induced by oxidative mutagen.

Elderberry (EDB) Sambucus nigra L. is one of the oldest medicinal plants which is useful for therapeutic and nutritional purposes due to a large amount of biologically active constituents, including compounds with a high antioxidant capacity. The present study focused on the antioxidant potential of the colon-available EDB fruit extract, derived from the artificial gastrointestinal tract, with regard to human colonic mucosa cells cultured in vitro. Despite the significant loss of EDB bioactive compounds due to the digestion process, the colon-digested extract was able to reduce the excessive intracellular ROS production (22%) and oxidative DNA damage (46%) in the colon cells at a dose of 1 mg of freeze-dried EDB powder/ml. Moreover, the colon-digested EDB extract inhibited oxidant-induced mutagenicity (26%) in the Salmonella typhimurium TA102 strain, as determined by the Ames test. In conclusion, the current in vitro study confirmed that the fruits of S. nigra are capable of protecting colonic cells against the detrimental effects of oxidative stress.