Effects of L-carnitine on the erythrocytes of stored human blood.

Objectives: This study aimed to assess the effects of L-carnitine on oxidative stress in human erythrocytes during storage.
Background: Using antioxidants as components of blood storage solutions may combat the effects of storage-induced oxidative stress on erythrocytes.
Methods: Blood from male adults was stored at 4 °C for 55 days in citrate phosphate dextrose adenine solution, without L-carnitine (Control) and with L-carnitine as an additive (at concentrations of 10, 30 and 60 mM - Experiments). Every fifth day, erythrocyte markers (morphology, count, haemoglobin, haemolysis and osmotic fragility), antioxidant defences (antioxidant enzymes and total antioxidant capacity) and oxidative stress markers (superoxides, lipid peroxidation and protein oxidation products) were analysed.
Results: Oxidative damage was observed in controls (day 25 onwards) and in experiments (day 35 onwards). L-carnitine (10 and 30 mM) protected erythrocytes from damage up to day 35 by maintaining haemoglobin and lipid peroxidation, assisting antioxidant enzymes and increasing antioxidant capacity by elevating sulfhydryls and ascorbic acid. L-carnitine was beneficial in prolonging storage up to 55 days but could not prevent oxidative damage completely in terms of haemolysis and osmotic fragility.
Conclusions: L-carnitine ameliorated oxidative stress, but combinations with other antioxidants may provide comprehensive protection to erythrocytes during storage.
(© 2019 British Blood Transfusion Society.)