Testing the effects of commercial cold pressed Cornelian cherry (Cornus mas) and Black currant (Ribes nigrum) juices on prevention of metabolic syndrome development in Wistar rats

[M. Paunović]

83 str.

biologija - fiziologija / Biology - Physiology

Metabolički sindrom (MetS) obuhvata skup simptoma, uključujući abdominalnu gojaznost, visok krvni pritisak, hiperglikemiju, nizak nivo HDL holesterola i povišenu koncentraciju triacilglicerida u krvi. Najčešće se razvija kao posledica dugotrajne ishrane s visokim sadržajem masti i šećera te niskim sadržajem vlakana. Procenjuje se da je ovo stanje prisutno kod četvrtine odrasle populacije, sa stalnom tendencijom povećanja broja novih slučajeva. Veliki broj studija pokazao je da konzumiranje plodova i proizvoda od voća bogatog polifenolima, ima blagotvorno dejstvo na kardiometaboličke parametre. Istovremeno, upotreba animalnih modela u prekliničkim studijama omogućava kontrolisane uslove i brže uočavanje potencijalnih efekata određenih tretmana. Zbog toga su ciljevi ove disertacije bili, prvo, uspostavljanje adekvatnog model sistema, a potom ispitivanje uticaja komercijalno dostupnih matičnih sokova drenjine i crne ribizle na prevenciju ishranom indukovanog metaboličkog sindroma kod pacova. Prvi deo studije obuhvatao je četiri kontrolne i četiri eksperimentalne grupe sa po šest mužjaka pacova Wistar soja. U studiji su korišćena dva podsoja, Kyoto i Hannover, kao i dve starosne grupe: pacovi stari osam nedelja i četiri meseca. Za ishranu je korišćen pelet obogaćen sa 25% suncokretovog ulja i 20% fruktoze (HFHF), a tretman je trajao ukupno 16 nedelja. Kao kontrola korišćene su životinje odgovarajućeg podsoja i starosti, hranjene standardnom hranom za pacove. Niti kod jedne eksperimentalne grupe nije došlo do razvoja MetS, tj. nijedna grupa nije pokazala prisustvo dovoljnog broja parametara koji bi potvrdili da je MetS dijagnostikovan. Ipak, Hannover podsoj starosti četiri meseca pokazao se kao najpodložniji ovom tipu nutritivne intervencije, zbog čega su te jedinke korišćene u daljoj studiji. Studija je nastavljena ispitivanjem efekata sokova bogatih polifenolima na prevenciju razvoja MetS. Za indukciju MetS korišćen je HFHF pelet u koji je dodato 0,1% holne kiseline (HFF). Istraživanje je obuhvatalo četiri grupe sa po devet pacova: Kontrolna grupu - na standardnoj ishrani, HFF grupa - na HFF peletu i vodi, CR grupa - na HFF peletu i 20% matičnom soku crne ribizle, D grupa - na HFF peletu i 20% matičnom soku drenjine. Tretman je trajao deset nedelja. Po završetku tretmana, ispitivan je uticaj suplementacije sokovima na biohemijske parametre, krvni pritisak, količinu visceralnog masnog tkiva, inflamaciju, biomarkere oksidativnog stresa u plazmi, jetri i masnom tkivu, histološke promene na jetri, adipocitima i pankreasu, kao i promene lipidnog profila u tkivima. Konzumiranje oba soka uticalo je na smanjenje nivoa holesterola u krvi i očuvanje histomorfologije tkiva, pospešilo je lučenje insulina i smanjilo lučenje glukagona, pokazalo preventivni efekat na porast koncentracije određenih pro-inflamatornih masnih kiselina u tkivima i doprinelo očuvanju redoks balansa u plazmi i tkivima. Suplementacija sokom crne ribizle pokazala se delotvornijom, jer je kod ove grupe zabeleženo i poboljšanje tolerancije na glukozu, smanjenje inflamacije u jetri, kao i smanjenje akumulacije visceralnog masnog tkiva izazvanog HFF ishranom. Dobijeni rezultati sugerišu da suplementacija datim sokovima, posebno crnom ribizlom, može imati višestruko blagotvorno dejstvo na prevenciju razvoja MetS. Na taj način, ovi sokovi bi mogli doprineti ublažavanju štetnih efekata široko rasprostranjene “zapadnjačke dijete“ bogate rafinisanim ugljenim hidratima, mastima i drugom procesuiranom hranom.

Metabolic syndrome (MetS) represents combined occurrence of symptoms such as abdominal obesity, high blood pressure, hyperglycemia, low HDL cholesterol, and elevated triglyceride levels in the blood. A long-term consumption of a diet high in fat and sugar and low in fiber proved to be the most common cause of MetS. It is estimated that this condition affects 20-30% of the adult population, with a constant upward trend in new cases. Numerous studies have shown that consuming polyphenol-rich fruits and their products has beneficial effects on cardiometabolic parameters. At the same time, the use of animal models in preclinical studies provides controlled conditions and allows for quicker screening of the potential effects of specific treatments. Therefore, the aims of this dissertation were, first, to establish an adequate model system, and then to examine the effects of commercially available black currant and cornelian cherry juices on the prevention of diet-induced MetS in rats. The first part of the study included four experimental and four control groups, six male Wistar rats each. Two sub-strains, Kyoto and Hannover, and two age groups, eight-week-old and four-month-old rats were used. The animals in experimental groups were fed with pellet enriched with 25% sunflower oil and 20% fructose (HFHF). The treatment lasted for a 16 weeks. Sub-strain and age-matched controls were fed a standard chow. None of the experimental groups developed MetS, i.e. no group showed a sufficient number of parameters to confirm the presence of MetS. However, the four-month-old Hannover sub-strain was found to be the most susceptible for this type of nutrition intervention, and that is the reason why this animals were used in further studies. The study continued by examining the effects of juices rich in polyphenols on the prevention of the development of MetS. Cholic acid (0.1%) was added to the HFHF pellets to get HFF diet used for MetS induction. The research included four groups of nine rats each: Control group - on a standard diet and water, HFF group - on HFF diet and water, BC group - on HFF diet and 20% black currant juice, CC group - on HFF diet and 20% cornelian cherry. The treatment lasted for 10 weeks. After completion of treatment, the effects of juice supplementation on biochemical parameters, blood pressure, visceral fat percentage, inflammation, oxidative status biomarkers in plasma, liver, and adipose tissue, histological changes in the liver, adipocytes, and pancreas, as well as on changes in the lipid profile in tissues were examined. Consumption of both juices led to a reduction in blood cholesterol levels and preservation of tissue morphology, increased insulin secretion and reduced glucagon secretion, prevented the increase in the concentration of certain pro-inflammatory fatty acids in tissues, and prevented the disruption of redox balance in plasma and tissues. Supplementation with black currant juice proved to be more effective, as this group also showed improved glucose tolerance, reduced liver inflammation, and reduced visceral fat accumulation induced by the HFF diet. The obtained results suggest that supplementation with these juices, especially black currant juice, may have multiple beneficial effects on the prevention of MetS development. In this way, these juices could contribute to mitigating the harmful effects of the widespread Western diet rich, in refined carbohydrates, fats and processed foods.

Metabolički sindrom, Hannover pacovi, Kyoto pacovi, HFF ishrana, sok od crne ribizle, sok od drenjine, inflamacija, oksidativni stres, masnokiselinski profil, imunohistološke analize

Metabolic syndrome, Hannover rats, Kyoto rats, HFF diet, Black currant juice, Cornelian cherry juice, Inflammation, Oxidative stress, Fatty acid profile, Immunohistological analyses

577.1:616-008(043.3)

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