Semenke lana, susama i golice i njihovi ekstrakti, ferulinska kiselina i enterolignani: efekti na lipidni status kod osoba na hemodijalizi, vezivanje za humani serum-albumin in vitro i uticaj na reaktivnost Cys34 tiolne grupe

Abstract

Poznato je da su semenke lana, susama i golice bogate esencijalnim masnim kiselinama i da predstavljaju značajni dijetarni izvor vitamina E i polifenola. Kod osoba sa hroničnom bubrežnom insuficijencijom, na programu hemodijalize, aktuelna su ispitivanja dijetarnih mera u cilju smanjenja incidence kardiovaskularnih oboljenja. Iz navedenog proizišao je cilj ove disertacije da se ispitaju efekti suplementacije ishrane smešom semenki lana, susama i golice kod bolesnika na hemodijalizi. Antioksidativna uloga humanog serum-albumina (HSA) u značajanoj meri određuje ukupnu antioksidativnu aktivnost u plazmi, a analiza HSA pokazala je da je kod bolesnika na programu hemodijalize smanjen sadržaj redukovane Cys34 tiolne grupe (od koje potiče antioksidativni potencijal HSA) i povećan stepen karbonilacije HSA. Stoga je drugi cilj ove disertacije bio da se in vitro ispita uticaj vezivanja komponenti ekstrakta smeše semenki lana, susama i golice, ferulinske kiseline (FE) i metabolita lignana (enterolaktona (EL) i enterodiola (ED), koji se povećavaju u cirkulaciji nakon konzumiranja namirnica bogatih biljnim lignanima), kao i masnih kiselina, na promenu konformacije HSA i reaktivnosti (antioksidativnog potencijala) Cys34 tiolne grupe, a da bi se sagledali mogući mehanizmi kojima komponente lana, susama i golice ostvaruju svoje in vivo efekte, pre svega antioksidativno dejstvo. Analizom masnokiselinskih profila ukupnih lipidnih ekstrakata smeše semenki gasnotečnom hromatografijom potvrđeno da je u semenkama lana najzastupljenija α-linolenska kiselina (ALA), a u semenkama susama i golice linolna kiselina (LA). Hladnoceđena ulja ispoljila su različitu antioksidativnu aktivnost (rafinisano suncokretovo ulje>maslinovo ulje>ulje lana>ulje golice> ulje susama) pri DPPH testu, u opsegu od 970 do 2000 μmola TE/1000 g ulja. Sadržaj hidrofilnih antioksidanasa u hladnoceđenim uljima je veoma nizak, sem za hladoceđeno maslinovo ulje. Pored lipofilnih antioksidanasa, pokazano je da metanolni ekstrakti obezmašćenih semenki (posebno lana) sadrže polifenole...

It is known that seeds of flax, sesame, and pumpkin are reach in essential fatty acids, and represent significant dietary source of vitamin E and polyphenols. In patients with chronic renal insufficiency, on hemodialysis treatment, research topics about dietary supplementations with aims to reduce incidence of cardiovascular diseases, are actual. Therefore, the goal of this dissertation was to investigate the effects of diet supplementation with the mixture of flax, sesame, and pumpkin seeds in patients on hemodialysis. The total antioxidative activity in plasma is significantly determined by antioxidative role of human serum albumin (HSA), and analysis of the HSA in patients on hemodialysis showed that the content of the free Cys34 thiol group (from which the HSA antioxidative potential originates) is reduced and on the other hand, degree of HSA carbonylation is increased. Thus, the second goal of this dissertation was in vitro investigation of the binding of flax, sesame, and pumpkins seeds extracts components, ferulic acid (FE) and lignan metabolites (enterolactone (EL), enterodiol (ED), which are increased in circulation after consumption of food reach with plants lignan), as well as fatty acids, on the conformational change of the HSA and on the reactivity (antioxidative potential) of Cys34 thiol group, with the final goal to perceive the possible mechanisms with which the flax, sesame, and pumpkin seeds explore in vivo antioxidative effects. Analysis of fatty acids profiles of total lipid extracts of seeds mixture using gas-liquid chromatography, confirmed that flaxseeds are the most abundant with α-linolenic acid (ALA), and sesame and pumpkin with linoleic acid (LA). Cold pressed oils showed different antioxidative activity (refined sunflower oil>olive oil>flaxseed oil>pumpkin oil>sesame oil) in the DPPH test (ranged from 970 to 2000 μmol TE/1000g oil). Content of hydrophilic antioxidants in cold pressed oils was extremely low, except for cold pressed olive oil. Besides lipophilic antioxidants, it was shown that methanol extracts of defatted seeds (particularly flaxseed) contain polyphenols. Antioxidative activity of the extracts (flax>sesame>pumpkin seeds), determined using DPPH and ABTS tests, was corresponded to the contents of total phenols in extracts...