Tag Archives: ω-3 polyunsaturated fatty acids

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

O. V. Ketsa, M. M. Marchenko

Fedkovich Chernivtsy National University, Ukraine;
e-mail: o.ketsa@chnu.edu.ua

Received: 21 May 2019; Accepted: 29 November 2019

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.

Liver cytochrome P450-hydroxylation system of tumor-bearing rats under the influence of ω-3 polyunsaturated fatty acids and vitamin D(3)

I. O. Shymanskyi1, O. V. Ketsa2, M. M. Marchenko2, М. М. Veliky1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: ihorshym@gmail.com;
2Fedkovich Chernovtsy National University, Chernovtsy

The study was performed to investigate the effects of the separate and combined action of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and vitamin D3 on the activity of the components of the oxygenase and reductase chains of the monooxygenase system (MOS) in the microsomal fraction isolated from the liver of rats with transplanted Guerin carcinoma. In the liver of the tumor-bearing rats during the intensive growth of the tumor (14 days, which corresponds to the logarithmic phase of tumor growth), the functional activity of the MOS was weakened. N-demethylase, p-hydroxylase and NADPH-cytochrome P450 reductase activity decreased, with the simultaneous enhancement of cytochrome P450 inactivation rate due to its transformation into an inactive form, cytochrome P420. In turn, we found an increase in the functional activity of the reductase chain of MOS, which components are known to transfer electrons from the reduced NADH through NADH-cytochrome b5-reductase and cytochrome b5 to cytochrome P450. In particular, the activity of NADH-cytochrome b5-reductase and the rate of reduction of cytochrome b5 were elevated with a simultaneous decrease in its content. Both ω-3 PUFAs and vitamin D3 administration to tumor-bearing rats for 42 days (28 days of preliminary administration and 14 days of tumor growth) significantly normalized the oxygenase activity of MOS, increasing NADPH-cytochrome P450-reductase, N-demethylase and p-hydroxylase activity of cytochrome P450 and blocking cytochrome P450 inactivation rate in the microsomal fraction of the liver. Administration of ω-3 PUFAs in combination with vitamin D3 led to the synergy. Changes in the activity of the components of the reductase chain of MOS in liver of tumor-bearing rats were observed mainly after ω-3 PUFAs supplementation. The content of cytochrome b5 increased and the rate of its reduction was significantly diminished. In the absence of a pronounced individual effect of vitamin D3 on the reductase chain of MOS, its co-administration with ω-3 PUFA was also found to be ineffective.

Monooxygenase system in Guerin’s carcinoma of rats under conditions of ω-3 polyunsaturated fatty acids administration

M. M. Marchenko, O. V. Ketsa, I. O. Shmarakov, K. H. Abutnaritsa

Fedkovich Chernovtsy National University, Ukraine;
e-mail: ketsa80@mail.ru

The aim of the study was to determine the variations of function in components of monooxygenase system (MOS) of rat Guerin’s carcinoma  under ω-3 polyunsaturated fatty acids (PUFAs) administration. The activity of Guerin’s carcinoma microsomal NADH-cytochrome b5 reductase, the content and the rate of cytochrome b5 oxidation-reduction, the content and the rate of cytochrome Р450 oxidation-reduction have been investigated in rats with tumor under conditions of ω-3 PUFAs administration. ω-3 PUFAs supplementation before and after transplantation of Guerin’s carcinoma resulted in the increase of NADH-cytochrome b5 reductase activity and decrease of cytochrome b5 level in the Guerin’s carcinoma microsomal fraction in the logarithmic phases of carcinogenesis as compared to the tumor-bearing rats. Increased activity of NADH-cytochrome b5 reductase facilitates higher electron flow in redox-chain of MOS. Under decreased cytochrome b5 levels the electrons are transferred to oxygen, which leads to heightened generation of superoxide (O2•-) in comparison to control. It was shown, that the decrease of cytochrome P450 level in the Guerin’s carcinoma microsomal fraction in the logarithmic phases of oncogenesis under ω-3 PUFAs administration may be associated with its transition into an inactive form – cytochrome P420. This decrease in cytochrome P450 coincides with increased generation of superoxide by MOS oxygenase chain.