Evaluation of preventive effects of bioactive food compounds against oxidative stress and intestinal inflammation. Study in human reconstructed intestinal 3D tissue model.

Sammanfattning

This study investigated the effects of induced oxidative stress and inflammation on intestinal mucosal barrier function with specific objective to investigate counteracting potential of the proteolytic enzymes such as bromelain and papain using reconstructed human small intestinal 3D tissue model (SMI-100). Four physiological conditions were modeled: healthy conditions (intact, n=12), inflamed (IL-6 treated, n=24), with or without induced oxidative stress (n=12). Prior to experiments with intestinal tissue model, the DPPH and ABTS assays were performed to determine radical scavenging capacity of bromelain and papain proteases in relation to their proteolytic activity, assessed via casein hydrolysis. Functional effects on epithelial barrier integrity and oxidative status were evaluated using transepithelial electrical resistance, Lucifer Yellow permeability and a CellROX DeepRed probe as an oxidative stress detector. Cell viability after treatments was assessed with an MTT assay. Papain exhibited consistently high antioxidant activity and enzymatic efficiency in the same concentration, while bromelain showed more prominent effects on intestinal mucosa as observed in the SMI-100 tissue model. Bromelain in dose of 1 mg/ml significantly reduced (p < 0,05) intracellular oxidative stress in IL-6-treated tissues, suggesting a context dependent antioxidant effect under inflammatory conditions. This concentration of bromelain also significantly increased epithelial permeability in IL-6-treated tissues. Bromelain demonstrated counteracting effects of induced oxidative stress in IL-6 treated intestinal mucosa (p < 0,01). No significant changes in TEER or cell viability were observed between treatments and experimental conditions. These findings emphasize the importance of studying bioactive compounds like fruit enzymes bromelain and papain under multiple stress conditions to better understand their therapeutic potential and safety in intestinal health.