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Open access

Marta Skowron, Jolanta Zalejska-Fiolka, Urszula Błaszczyk, Ewa Chwalińska, Aleksander Owczarek and Ewa Birkner

Abstract

Introduction: The aim of this study was to investigate whether the type and form of oil (raw/non-oxidised (N) or post-frying/oxidised (O)) consumed in high-fat diets affect the oxidative status of an organism, as observed by malondialdehyde (MDA) concentration as an oxidative factor and antioxidant enzyme activity.

Material and Methods: Fats in the diet came from rapeseed oil (R) and olive oil (O).

Results: The applied diet caused a decrease in MDA concentration (μmol/L) in serum in group RN from 2.94 ± 0.87 to 1.76 ± 0.13, in group ON from 2.45 ± 0.62 to 1.50 ± 0.10, and in group OO from 2.70 ± 1.16 to 1.84 ± 0.36. Meanwhile, MDA concentration (mmol/L) increased in blood haemolysate in group RO from 0.15 ± 0.07 to 0.22 ± 0.03 and in group OO from 0.17 ± 0.02 to 0.22 ± 0.02. The observed changes caused a response of the enzymatic antioxidant system in both models, especially followed by an increase in activities of total superoxide dismutase and its mitochondrial isoenzyme in all experimental groups, while its cytosolic isoenzyme activity increased only in ON and OO groups. Increased activity of glutathione peroxidase (GPX) in groups RN and RO and of catalase (CAT) in groups ON and OO was observed. Significant differences in responses to the different types and forms of oils were probably caused by the different oxidative stability of the studied oils.

Conclusion: This diet disturbed the body’s oxidative status; however, during the six-month study the enzymatic antioxidant system remained effective.

Open access

Barbara Stawiarska-Pięta, Jolanta Zalejska-Fiolka, Magdalena Wyszyńska, Anna Kleczka, Beata Janiga, Natalia Grzegorzak and Ewa Birkner

Abstract

Introduction: The aim of the study was to assess the influence of α-lipoic acid (ALA) on the morphology of the aorta and liver of rabbits fed high fat diet with addition of oxidised (ORO) and non-oxidised rapeseed oil (N-ORO).

Material and Methods: The study was conducted on male chinchilla rabbits divided into six groups. The control group (C) was fed a breeding standard diet (BSD), group I received BSD with the addition of ALA in the dose of 10 mg/kg b.w., groups II and III received BSD enriched with 10% addition of N-ORO or ORO, whereas rabbits from groups IV and V received BSD with 10% addition of N-ORO or ORO and ALA.

Results: Addition of ORO caused necrosis and steatosis of hepatocytes, as well as atherosclerotic plaques of various intensification in the aorta. In the liver of rabbits from group II (N-ORO) infiltrations of mononuclear cells was observed in the area of liver triads and between liver lobules. The beneficial influence of ALA was demonstrated in rabbits fed a diet containing N-ORO or ORO. In case of ORO, the activity of ALA was not fully effective.

Conclusion: Diet supplementation with ALA counteracts the changes generated in the liver and aorta under increased exposure to higher fat content in diet, in particular thermally treated fats.

Open access

Jolanta Zalejska–Fiolka, Aleksandra Kasperczyk, Sławomir Kasperczyk, Barbara Stawiarska-Pięta, Rafał Fiolka and Ewa Birkner

Abstract

For 24 weeks, rabbits were fed feed containing non-oxidised or oxidised rapeseed oil. At the beginning of the experiment and every six weeks the rabbits were weighed and blood was taken. After the experiment was completed, their liver was dissected for biochemical and histological examinations. The activity of alanine aminotransferase, aspartate aminotrasferase, glutamate dehydrogenase, sorbitol dehydrogenase, and aldolase in blood plasma and liver were determined. Enzymes of the protein and liver metabolic pathways were determined using kinetic and spectrophotometric methods. The content of fatty acids was determined by means of fatty acid methyl ester concentration measurement using gas chromatography. It was found that the applied diet with oxidised rapeseed oil caused the development of slight liver steatosis and disturbances in the activity of enzymes involved in the liver pathways, despite the fact that it was a balanced diet, and differed only in the ratio of saturated to unsaturated fatty acids. The obtained results indicate that more profound oil oxidation and its increased supply in diet may result in the development of liver steatosis.