Učinak antiepileptika valproata i flavanona naringina na antioksidacijski sustav obrane u mozgu, jetri i bubregu

doctoral thesis

• Title (english): The effects of the antiepileptic drug valproate and of the flavanone naringin on the antioxidative defense system in the brain, liver and kidney
• Author: David Jutrić
• Mentor: Domagoj Đikić (mentor)
• Committee member: Vesna Benković (predsjednik povjerenstva)
• Committee member: Irena Landeka Jurčević (član povjerenstva)
• Committee member: Dubravka Rašić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; Zagreb
• Defense date and country: 2022-05-26, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology
• Universal decimal classification (UDC): 577 - Biochemistry. Molecular biology. Biophysics

Abstract

Valproat je često korišten antiepileptički lijek. Neželjene pojave kod predoziranja ili
produljenog unosa uključuju oksidaciju neurona, hepatičnu steatozu i zatajenje jetre, te
Fankonijev sindrom. Velik broj istraživanja usmjeren je prema mogućnostima umanjivanja tih
nepovoljnih učinaka sinergijskim uzimanjem prirodnih bioaktivnih molekula, primjerice
naringina. C57BL6 miševi oba spola bili su svakodnevno, tijekom 10 dana, tretirani
individualnim dozama i kombinacijom od 150 mg/kg valproata i 25 mg/kg naringina, prirodnog
bioaktivnog polifenola iz citrusnih biljaka. Također su tretirane HepG2 i PK stanice in vitro.
Između skupina tretiranih valproatom, naringinom te kombinacijom ova dva spoja, u mozgu,
jetri i bubregu, uspoređena je peroksidacija lipida (analizom malondialdehida, MDA), te glavni
markeri antioksidacijske stanične obrane (superoksid dismutaza-SOD, katalaza-CAT,
reducirani glutation-GSH). Koncentracije MDA, CAT i GSH uspoređeni su i u in vitro pokusu.
Dodatno su u jetri analizirani transkripcijski faktori i enzimi lipidnog metabolizma (PPARα,
PGC1α, ACOX1, NFE2R2) i nastanak steatoze. Cilj je bio utvrditi može li primjena naringina
ublažiti nuspojave valproata, te do koje mjere se parametri mijenjaju u pokusu in vivo i in vitro.
Uspoređeni su rezultati između muškog i ženskog spola. U korteksu velikog i središnjeg mozga,
te u jetri i bubregu valproat uzrokuje lipidnu peroksidaciju. Naringin je također uzrokovao
lipidnu peroksidaciju ali samo u mozgu i bubregu vjerojatno zbog prooksidacijskog djelovanja
katalitičkih doza naringina u apolarnom okruženju. Naringin u kombinaciji s valproatom je
ublažio oštećenje bubrega i jetre, donekle je zaštitio mozak, a razine lipida i triglicerida u
serumu, te steatozu jetre vratio je u kontrolne razine. Naringin je normalizirao razine
transkripcijskih čimbenika PPARα i PGC1α u jetri, a razine acetilCoA oksidaze 1 (ACOX1)
koje valproat podiže, je spustio u kontrolne razine. Zabilježen je značajno veći oksidacijski stres
kod mužjaka, vjerojatno jer su ženke zaštićene antioksidacijskim djelovanjem estrogena. In
vitro model pokusa bi mogao služiti kao predskazatelj in vivo staničnih odgovora, ili ga
zamjeniti ali uz određene predtretmane hormonima i metabolitima koje treba dodatno istražiti.

Abstract (english)

Valproate is a commonly used antiepileptic drug. Side effects from overdose or prolonged
intake include the oxidation of neurons, hepatic steatosis and liver failure, as well as Fancony
Syndrome. Extensive research has been done as to elucidate whether the adverse effects can be
reduced by synergistic intake of natural bioactive molecules. C57Bl6 mice of both sexes were
exposed for 10 days to individual and combined doses of 150 mg/kg valproate and 25 mg/kg
naringin, a natural bioactive polyphenol from citrus plants. HepG2 and PK cells were also
exposed in vitro. In the brain, liver and kidney, the valproate-induced, naringin-induced, and
combination of these two compounds-induced lipid peroxidation (via malondialdehyde
analysis, MDA), as well as the main markers of antioxidant cellular defense (superoxide
dismutase-SOD, catalase-CAT, reduced glutathione-GSH) were compared in vivo and to the in
vitro experiment. Additionally, transcription factors and enzymes of lipid metabolism (PPARα,
PGC-1α, ACOX1, NFE2R2) and steatosis were analyzed in the liver. The aim was to determine
whether the use of naringin reduces the side effects of valproate in vivo and in vitro experiments.
The results were compared between the sexes as well. In the frontal and middle cerebral cortex,
liver and kidney valproate caused lipid peroxidation. Naringin also caused lipid peroxidation
but only in the brain and kidney, likely because of the pro-oxidant activity of catalytic doses of
naringin in apolar environments. Naringin in combination with valproate did decrease damage
to the liver and kidney, somewhat to the brain, and it did bring the levels of lipids and
triglycerides, as well as the liver steatosis close to control levels. Naringin normalized the levels
of PPARα and PGC-1α in the liver, and it brought the levels of acetyl CoA oxidase 1 (ACOX1)
which valproate increases, close to control levels. A significantly higher oxidative stress was
recorded in the male group, probably because of the antioxidant protection by estrogen afforded
to females. The in vitro model could serve as a predictor of in vivo cellular responses, or as a
replacement of in vivo models, although certain pretreatments with hormones and metabolites
maybe necessary and should further be investigated.

• Keywords: oksidacijski stres; antiepileptik; polifenoli; metabolizam lipida; transkripcijski faktori; steatoza
• Keywords (english): oxidative stress; antiepileptic; polyphenols; lipid metabolism; transcription factors; steatosis
• Language: croatian
• URN:NBN: urn:nbn:hr:217:598078
• Promotion: 2022
• Study programme: Title: Biology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija (doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-11-22 12:19:24