Modification of enzymatic and non-enzymatic in vitro oxidative defence system by bioaccessible phytonutrients of selected spices

- The bioaccessibility and bioactivity in vitro of spice has been investigated.
- The amount of bioaccessible polyphenols increases during gastrointestinal digestion.
- Compounds released during in vitro digestion and absorbed showed high antioxidant potential.
- Spice phytochemicals modified the activity of anti - and pro - oxidant enzymes.

The bioaccessibility and bioactivity of spice polyphenols using the in vitro model simulating gastro-intestinal conditions and intestinal absorption has been investigated.The amount of bioaccessible polyphenols, flavonoids and phenolic acids increases during gastrointestinal digestion. All dialysates obtained after digestion were characterized by lower content of phenolics compounds in a comparison with digested samples but higher in comparison with raw material. It was found that compounds obtained after simulated digestion and absorbed showed significantly higher antioxidant potential than raw materials. Additionally, absorbed extracts of spices significantly modified the activity of enzymes involved in the enzymatic defence system (activation of superoxide dismutase and catalase) and activity of prooxidant enzymes (inhibition of lipoxygenase and xanthine oxidase).Our results suggest that the gastro-intestinal tract may act as an extractor where polyphenols are progressively released from solid matrix and made available for the absorption or to exert their biological effects in the gastro-intestinal tract.