Polifenoli iz vinskog taloga kao nove funkcionalne bioaktivne tvari za prevenciju oksidacijskog stresa i hiperlipidemije

The study examines the potential of wine industry by-product, the lees, as a rich mixture of natural polyphenols, and its physiological potential to reduce postprandial metabolic and oxidative stress caused by a cholesterol-rich diet in in vivo model. Chemical analysis of wine lees showed that their total solid content was 94.2 %. Wine lees contained total phenols, total nonflavonoids and total flavonoids expressed in mg of gallic acid equivalents per 100 g of dry mass: 2316.6±37.9, 1332.5±51.1 and 984.1±28.2, respectively. The content of total anthocyanins expressed in mg of cyanidin-3-glucoside equivalents per 100 g of dry mass was 383.1±21.6. Antioxidant capacity of wine lees determined by the DPPH and FRAP methods and expressed in mM of Trolox equivalents per 100 g was 259.8±1.8 and 45.7±1.05, respectively. The experiment lasted 60 days using C57BL/6 mice divided in four groups: group 1 was fed normal diet and used as control, group 2 was fed normal diet with added wine lees, group 3 was fed high-cholesterol diet (HCD), i.e. normal diet with the addition of sunflower oil, and group 4 was fed HCD with wine lees. HCD increased serum total cholesterol (TC) by 2.3-fold, triacylglycerol (TAG) by 1.5-fold, low-density lipoprotein (LDL) by 3.5-fold and liver malondialdehyde (MDA) by 50 %, and reduced liver superoxide dismutase (SOD) by 50 %, catalase (CAT) by 30 % and glutathione (GSH) by 17.5 % compared to control. Conversely, treatment with HCD and wine lees reduced TC and LDL up to 1.4 times more than with HCD only, with depletion of lipid peroxidation (MDA) and restoration of SOD and CAT activities in liver, approximating values of the control. HDL levels were unaffected in any group. Serum transaminase activity showed no hepatotoxic properties in the treatment with lees alone. In the proposed model, wine lees as a rich polyphenol source could be a basis for functional food products without alcohol.U radu je istražena moguća uporaba vinskog taloga, polifenolima bogatog otpadnog proizvoda u industriji vina, u prehrani i ispitan je njegov fiziološki učinak na smanjenje oksidacijskog stresa uzrokovanog konzumacijom hrane bogate kolesterolom na modelu in vivo. Kemijskom je analizom utvrđeno da je udjel čvrste tvari u vinskom talogu bio 94,2 %; ukupnih fenola 2316,6±37,9; neflavonoida 1332,5±51,1 i flavonoida 984,1±28,2 mg u 100 g suhe tvari, izražen kao ekvivalent galne kiseline. Udjel ukupnih antocijana bio je 383,11±21,6 mg u 100 g suhe tvari, izražen kao ekvivalent cijanidin-3-glukozida. Ukupni antioksidacijski potencijal određen pomoću metode DPPH bio je (259,8±1,8) mM Trolox ekvivalenta u 100 g suhe tvari, a pomoću metode FRAP (45,7±1,05) mM u 100 g suhe tvari. Kvalitativni udjel polifenola određen je HPLC-om. Miševi C57/Bl6 hranjeni su tijekom 60 dana jednim od tipova prehrane: (i) normalnom hranom (kontrolna skupina), (ii) hranom s dodatkom ekstrakta vinskog taloga (1 g suhe tvari po kg po danu), (iii) hranom s velikim udjelom kolesterola (2 % kolesterola u 2 mL ulja po životinji po danu), i (iv) hranom bogatom kolesterolom (kao skupina 3) s dodatkom ekstrakta vinskog taloga (kao skupina 2). Kolesterolom bogata ishrana povećala je (p<0,05) razinu ukupnog kolesterola u serumu za 2,3; triacilglicerida za 1,5; LDL kolesterola za 3,5 puta, zatim je povećala razinu malondialdehida u jetri (p<0,05) i reducirala aktivnost superoksid dismutaze za 50 %, katalaze za 30 % i glutationa za 17,5 % u odnosu na kontrolni uzorak. Ishrana bogata kolesterolom s dodatkom ekstrakta vinskog taloga smanjila je (p<0,05) razinu ukupnog i LDL kolesterola za 1,4 puta u odnosu na skupinu hranjenu hranom bogatom kolesterolom, uz smanjenje (p