20.500.12556/RUL-164573 Vrednotenje antioksidativne zaščite izbranega fosfolipida z bilirubinom in biliverdinom Evaluation of antioxidant protection of selected phospholipid with bilirubin and biliverdin Celične membrane so sestavljene iz fosfolipidov, ki vsebujejo polinenasičene maščobne kisline. Te so zaradi prisotnosti dvojnih vezi v veliki meri podvržene lipidni peroksidaciji, do katere pride zaradi nastanka radikala. Posledica lipidne peroksidacije je oksidacija lipida in posledično poškodbe celične membrane. Oksidacijo lipidov lahko učinkovito upočasnimo ali celo preprečimo z dodatkom ustreznega antioksidanta. Celične membrane so strukturno zelo podobne liposomom, zato liposomi predstavljajo dober model za vrednotenje antioksidativne zaščite lipida z izbranimi antioksidanti. Bilirubin in njegov prekurzor biliverdin sta endogena antioksidanta, ki nastaneta pri razgradnji hema. Bilirubin ima v telesu pomembno vlogo pri zaščiti ledvic, srca in možganov pred oksidativnimi poškodbami, vendar pa lahko njegova prisotnost v previsokih koncentracijah vodi do različnih bolezenskih stanj, katerih simptom je zlatorumeno obarvanje kože in sluznic – zlatenica. V okviru eksperimentalnega dela magistrske naloge smo iz izbranega fosfolipida 1,2-didokozaheksaenoil-sn-glicero-3-fosfoholina s filmsko metodo izdelali liposome z dodanim različnim deležem bilirubina in biliverdina ali brez antioksidanta. Liposome smo izpostavili kisiku in v različnih časovnih točkah vrednotili koncentracijo preostalega lipida. Kvantitativno analizo smo izvedli s tekočinsko kromatografijo ultravisoke ločljivosti in z detektorjem nabitih aerosolov. Dokazali smo, da lipid brez prisotnosti antioksidanta, v atmosferi s kisikom, zelo hitro oksidira. Z rezultati naših eksperimentov, kjer smo spreminjali deleže bilirubina in biliverdina v vzorcih liposomov, smo potrdili, da je učinkovitost antioksidativne zaščite odvisna od identitete in koncentracije antioksidanta: biliverdin je izkazal sposobnost zaščite lipidov pred oksidacijo že pri nižjih koncentracijah v primerjavi z bilirubinom. Cell membranes are composed of phospholipids containing polyunsaturated fatty acids. Due to the presence of double bonds, these are highly susceptible to lipid peroxidation, which occurs through radical formation. The consequence of lipid peroxidation is lipid oxidation and subsequent damage to the cell membrane. Lipid oxidation can be effectively slowed down or even prevented by adding an appropriate antioxidant. Cell membranes are structurally very similar to liposomes, making liposomes a good model for evaluating the antioxidant protection of lipids with selected antioxidants. Bilirubin and its precursor biliverdin are endogenous antioxidants that are formed during the breakdown of heme. Bilirubin plays an important role in protecting the kidneys, heart, and brain from oxidative damage in the body, but its presence in excessively high concentrations can lead to various disease states, a symptom of which is the yellowish discoloration of the skin and mucous membranes—jaundice. As part of the experimental part of the master's thesis, we manufactured liposomes from the selected phospholipid 1,2-didocosahexaenoyl-sn-glycero-3-phosphocholine using the film method, with varying proportions of bilirubin and biliverdin added or without any antioxidant. We exposed the liposomes to oxygen and evaluated the concentration of remaining lipid at various time points. Quantitative analysis was performed using ultra-high performance liquid chromatography with a charged aerosol detector. We demonstrated that the lipid, without the presence of an antioxidant, oxidizes very quickly in an oxygen atmosphere. The results of our experiments, where we varied the proportions of bilirubin and biliverdin in liposome samples, confirmed that the effectiveness of antioxidant protection depends on the identity and concentration of the antioxidant: biliverdin demonstrated the ability to protect lipids from oxidation at lower concentrations compared to bilirubin. antioksidanti bilirubin biliverdin liposomi lipida peroksidacija tekočinska kromatografija ultraviskoke ločljivosti antioxidants bilirubin liposomes lipid oxidation ultrahigh-performance liquid chromatography true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2024-10-31 08:45:19 2024-10-31 08:45:27 2024-11-22 14:54:53 0000-00-00 00:00:00 2024 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1970-01-01 114270 25621.pdf 25621.pdf 1 1F091D57C1F556CD387D04B88E2DC37C 7c7aeb1c1c88317806155e335b6051b4a61b78f9ce8afffe99c46aa543027ee8 c63e1dce-975b-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=195097 Fakulteta za farmacijo 0 0 0