Free radical oxidation in liver mitochondria of tumor-bearing rats and its correction by essential lipophilic nutrients

The role of free radical oxidation in the increase of mitochondrial membranes permeability in organs which are not involved in oncogenesis and the development of the methods for preventing mitochondria dysfunction remain topical problems. In this work, the interconnection of lipid peroxidation (LPO) in liver mitochondrial fraction with the processes of mitochondrial swelling and cytochrome с release to the cytosol under separate and combined administration of ω-3 polyunsaturated fatty acids (PUFAs) and retinol acetate (vitamin A acetate) to rats with transplanted Guerin’s carcinoma was studied. During the intensive tumor growth (14 days) the increase of superoxide radical generation and the content of primary (triene conjugates, TC), secondary (ketodienes and coupled trienes, CD+CT) and terminal (Schiff bases) lipid peroxidation products­ in the mitochondrial fraction of tumor-bearing rats was detected, which contributed to the mitochondrial swelling and cytochrome с release to the cytosol. Separate administration of ω-3 PUFAs to tumor-bearing rats decreased both free radical processes in mitochondrial fraction and mitochondrial swelling. Separate administration of retinol acetate in a high dose (3000 IU/kg of body weight) intensified free radical processes in the mitochondrial fraction of tumor-bearing rats, while administration of retinol acetate in a physiological dose (30 IU/kg of body weight) did not lead to changes compared to tumor-bearing rats that did not receive the drug. The prooxidant effects of retinoid were partially eliminated in the case of combined administration with ω-3 PUFA.