Bovine plasma hydrolysates' iron chelating capacity and its potentiating effect on ferritin synthesis in Caco-2 cells.

The low bioavailability of iron is one factor that contributes to its deficiency in the human diet. For this reason, it is necessary to find compounds that can form iron chelates so that these can be added to foods that contain iron to improve its bioavailability at the intracellular level. In this study, we assessed the relationship between bovine plasma hydrolysates' iron chelating ability and their degree of hydrolysis. The hydrolysate with the highest chelating capacity was fractionated and each fraction's chelating capacity was subsequently assessed. Each fraction's effect on ferritin synthesis in Caco-2 cells was also determined. The results showed that bovine plasma hydrolysates with a degree of hydrolysis of 19.1% have an iron chelating capacity of 38.5 ± 0.4% and increase the synthesis of ferritin in Caco-2 cells five-fold compared to the control. This may be due to the fact that these hydrolysates contain amino acids such as Leu, Lys, Glu, Ala, Asp, Val, Thr, Cys and Phe, which may be responsible for binding iron to the hydrolysate, increasing its solubility and the consequent uptake by Caco-2 cells.

Changes in alpha-tocopherol and retinol levels during cardiopulmonary bypass correlate with maximal arterial partial pressure of oxygen.

Cardiopulmonary bypass (CPB) is associated with oxidative stress. This study examined antioxidant levels in adults undergoing CPB surgery and their correlation with clinical variables. Arterial blood samples were obtained from 27 patients undergoing CPB. The time-course variation of vitamin C (spectrofluorimetry), alpha-tocopherol and retinol (HPLC) levels were determined. Plasma vitamin C rose initially but gradually decayed during reperfusion until 60% reduction of baseline values post-surgery. alpha-Tocopherol and retinol were reduced along CPB with post-operative values approximately 25% lower than baseline. No significant changes were found for selenium and glutathione peroxidase. PaO(2) values rose steadily throughout CPB. A correlation existed for alpha-tocopherol and retinol depletion vs maximal PaO(2) throughout CPB but no correlation was found for antioxidant consumption vs duration of ischaemia and reperfusion and hypothermia level. In conclusion, consumption of arterial blood antioxidant vitamins occurs with CPB in relation with PaO(2) levels but not for other clinical variables measured in this study.

Evaluation of the antioxidant capacity, furan compounds and cytoprotective/cytotoxic effects upon Caco-2 cells of commercial Colombian coffee.

Antioxidant capacity (AC), total phenolics (TPs), furan compounds (HMF and furfural F) and cytoprotective/cytotoxic effects upon Caco-2 cells (MTT, cell cycle and reactive oxygen species (ROS)) were evaluated in Colombian coffee (2 ground and 4 soluble samples). The AC (ABTS and FRAP), TPs and HMF ranged between 124-722, 95-802µmoles Trolox/g, 21-100mg gallic acid/g and 69-2900mg/kg, respectively. Pretreatment of cells for 24h with lyophilized coffee infusions at the highest dose without cytotoxic effects (500µg/mL) significantly prevented the decrease in cell viability compared to control stress with H2O2 (5mM/2h), recovering viability to values between 34% and 45% and restoring the control values without stress induction in the G1 phase of cell cycle. After exposure to stress, four extracts decreased ROS values significantly to 22.5-24.9%. The coffee samples exerted a cytoprotective effect against oxidative stress, with improvement in cell viability and a reduction of intracellular ROS.