The creation of new lithium compounds with antioxidant activity is relevant problem for psychiatry. The aim of this work was study of the protective effect of lithium salts against ethanol-induced oxidative damage to proteins and lipids of human blood plasma in vitro.

We used lithium ascorbate and lithium carbonate 0.6 mmol/L which correspond to the therapeutic dose (in terms of lithium ions). Antioxidant carnosine (β-Ala-L-His) was used as comparison drug. We used the blood of 12 healthy donors. The heparinized blood samples were incubated in presence of tested preparations for one hour at 37 °C. The final ethanol concentration in samples was 0.5%. Oxidative modification of proteins was determined as the level of carbonylated proteins with 2.4–dinitrophenilhydrazine, lipid peroxidation products–as the level of TBA-reactive products by spectrometry. Statistical analysis was performed with “Statistika 10” program.

The addition of ethanol in the blood led to a significant increase in carbonylated proteins and TBA-reactive products in the plasma (carbonylated proteins: without ethanol 0.26 ± 0.01 nmol/mg of protein; with ethanol 0.33 ± 0.02 nmol/mg; TBA-reactive products: without–3.2 ± 0.1 nmol/mL; with–4.0 ± 0.2 nmol/mL, P < 0.05). In the presence of carnosine such increase of oxidized products of biomolecules is not observed, i.e. carnosine had a protective effect against ethanol-induced oxidative damage. Lithium ascorbate showed a protective effect like carnosine. Lithium carbonate revealed no detectable influence on biomolecules in the conditions of our experiment.

Lithium ascorbate has a protective effect on blood plasma proteins and lipids under ethanol-induced oxidative damage of biomolecules.

The authors have not supplied their declaration of competing interest.