Time dependent formation of markers of oxidative stress induced by a high fat diet supplemented or unsupplemented with vitamin E in pigs

Pajk Žontar, Tanja (author), Salobir, Janez (author), Rezar, Vida (author)

The time dependent formation of oxidative damage induced by polyunsaturated fat in the diet was investigated in an experiment with pigs as a model for humans. The role of vitamin E in the prevention of oxidative stress was also studied. Twenty-four growing pigs were penned individually and after an adaptation period divided into three groups. All groups received isocaloric daily rations composed of a basal diet isocalorically supplemented with: starch, linseed oil or linseed oil and vitamin E. Oxidative stress was evaluated by measuring the degree of lymphocyte and granulocyte nuclear DNA damage, concentration of malondialdehyde (MDA) in blood plasma, 24-hour urine MDA excretion rate and concentration of vitamin E isomers in the blood at the beginning, after 24 hours, after 6 days and at the end of the 22 day experimental period. The results confirmed that a high proportion of polyunsaturated fat in the diet increased lymphocyte and granulocyte DNA damage only after 6 days. The lymphocytes appear to be more sensitive to this type of oxidative stress than granulocytes. The MDA concentration in the blood and urinary MDA excretion after 24 hours of oxidative stress seem to be more accurate indicators than the rate of lymphocyte and especially granulocyte DNA damage. Vitamin E supplementation effectively protects the blood cells against increased DNA damage during the whole course of the experiment, but failed to reduce MDA formation significantly 24 hours and 6 days after the beginning of oxidative load. The study further suggests that supplementation of vitamin E is able to completely prevent DNA damage of both types of investigated blood cells at any time, but is only able to reduce the formation of lipid peroxidation products after prolonged treatment.

• Language: English
• Keywords: pigs, animal nutrition, oxidative stress, DNA damage, polyunsaturated fatty acids, PUFAs, vitamin E, comet assay, malondialdehyde
• Work type: Not categorized
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Year: 2009
• Number of pages: Str. 103-110
• Numbering: Letn. 94, št. 2
• PID: 20.500.12556/RUL-317
• UDC: 636.4.084/.087
• ISSN on article: 1581-9175
• COBISS.SI-ID: 2544008
• Publication date in RUL: 11.07.2014

Record is a part of a journal

• Title: Acta agriculturae Slovenica
• Shortened title: Acta agric. Slov.
• Publisher: Biotehniška fakulteta
• ISSN: 1581-9175
• COBISS.SI-ID: 213840640

Secondary language

• Language: Slovenian

Abstract

V raziskavi smo spremljali časovno odvisnost oksidacijskega stresa, povzročenega z dodatkom večkrat nenasičenih maščobnih kislin (VNMK) ter vlogo vitamina E pri njegovem zmanjšanju. Poskus smo izvedli na prašičih kot modelu za človeka. V individualne bilančne kletke smo uhlevili 24 mladih rastočih prašičev ter jih po obdobju prilagajanja razdelili v tri skupine. Vse tri skupine so dobivale enake osnovne izokalorične dnevne obroke z dodatki skroba,lanenega olja ali lanenega olja in vitamina E. Oksidacijski stres smo ovrednostili kot stopnjo poškodb jedrne DNK limfocitov in gralulocitov, koncentracijo malondialdehida (MDA) v krvni plazmi, 24-urno izločanje MDA s sečem in koncentracijo izomer vitamina E v krvni plazmi. Vrednosti navedenih parametrov so bile določene na začetku poskusa, po 24 urah, po 6 dneh in na koncu 22 dnevnega poskusa. Rezultati so pokazali, da je visoka vsebnost večkrat nenasičenih maščobnih kislin (VNMK) v prehrani povečala poskodbe jedrne DNK limfocitov in granulocitov ye po 6 dneh. Limfociti so se, v primerjavi z granulociti, izkazali kot bolj občutljivi. Koncentracija MDA v krvni plazmi in v 24-tih urah izločena količina MDA s sečem se je v našem primeru izkazala kot boljši pokazatelj oksidacijskega stresa v primerjavi s stopnjo poskodb DNK limfocitov, se posebno granulocitov. Dodatek vitamina E je učinkovito zaščitil krvne celice pred povečanimi poškodbami DNK v celotnem poskusnem obdobju, medtem ko smo po 24 urah in tudi po 6 dneh ugotovili statistično značilno večjo koncentracijo MDA v primerjavi z začetnimi vrednostmi. Na osnovi dobljenih rezultatov lahko sklepamo, da dodatek vitamina E oba tipa preiskovanih krvnih celic v celoti zaščiti pred poškodbami DNK, nastajanje produktov lipidne peroksidacije pa se lahko zmanjša le po dolgotrajnejsem dodajanju.