In-vitro antioxidant capacity and cytoprotective/cytotoxic effects upon Caco-2 cells of red tilapia (Oreochromis spp.) viscera hydrolysates.

The antioxidant capacity of red tilapia viscera hydrolysates (RTVH) with different degrees of hydrolysis (DH) as well as their ultrafiltration membrane fractions, were analyzed using different chemical assays. Their protective effects against oxidative stress were evaluated using H 2 O 2 -stressed human intestinal differentiated Caco-2. The highest antioxidant capacity was obtained with a DH of 42.5% (RTVH-A) and its <1 kDa fraction (FRTVH-V). RTVH-A and FRTVH-V did not show cytotoxic effects at a concentration of ≤0.5 mg/mL,prevented the decrease in cell viability, and suppressed intracellular reactive oxygen species (ROS) accumulation induced by H 2 O 2. However, pretreatment with RTVH-A after adding H 2 O 2 , showed a greater decrease in glutathione levels. Moreover, FRTVH-V allowed for a recovery close to that of control levels of cell proportions in the G1 and G2/M cell cycle phases; and a decrease in the cell proportion in late apoptosis. These results suggest that RTVH-A and FRTVH-V can be beneficial ingredients with antioxidant properties and can have protective effects against ROS-mediated intestinal injuries. Unlabelled Image • The most antioxidant hydrolysate from red tilapia viscera was generated with DH of 42.5% (RTVH-A). • RTVH-A purification showed low molecular mass peptides had higher antioxidant activity. • RTVH-A and its <1-kDa fraction preserve Caco-2 viability and decrease ROS production. • <1-kDa fraction peptides protect Caco-2 cells from H 2 O 2 -induced oxidative stress. [ABSTRACT FROM AUTHOR]