Ispitivanje antioksidativnog statusa mleka majki prevremeno rođene dece

Abstract

Prevremeno rođena deca su posebno ugrožena zbog skromnijeg antioksidativnog potencijala u kombinaciji sa većom izloženošću oksidativnom stresu. Naime, oksidativni stres izazivaju visoke koncentracije kiseonika, fototerapija i intravenska primena lipida koji su deo nužnog terapijskog pristupa ovoj populaciji dece, kao i učestale infekcije. Humano mleko (HM) predstavlja složeni biološki fluid koji ima antioksidaciona svojstva. Antioksidativni enzimi prisutni u HM su superoksid dismutaza (SOD), katalaza (CAT), glutation peroksidaza (GSH-Px) i glutation reduktaza (GR). Neenzimski antioksidansi u HM su vitamin C, E, beta-karoten, glutation, laktoferin, koenzim Q, beta-endorfini i drugi. Ishrana humanim mlekom kod prevremeno rođene dece ima važnu ulogu u prevenciji oksidativnog stresa. Cilj: Određivanje ukupnog antioksidativnog kapaciteta (UAK) mleka majki prevremeno rođene dece tokom laktacije (kolostrum, prelazno i zrelo mleko). Određivanje UAK zrelog svežeg HM i poređenje sa zrelim HM koje je termički obrađeno (skladištenjem u frižideru, zamrzavanjem ili pasterizacijom ), sa HM u koga je dodat obogaćivač, kao i adaptiranom mlečnom formulom za ishranu prevremeno rođene dece. Upoređen je i antioksidativnni status zrelog obogaćenog mleka i adaptirane mlečne formule za ishranu prevremeno rođene dece. Materijal i metode istraživanja: Ova kohortna studija je obuhvatila 30 majki prevremeno rođene dece (porođaj pre 37. gestacijske nedelje), kod kojih je uspostavljena laktacija, prema redosledu prijema u Institut za neonatologiju u Beogradu, u periodu od 01.12.2014. do 31.05.2016. Uzorci HM su od svake majke uzimani tri puta. Naime UAK je određivan u svežem HM uzorkovanom u prva 3 dana nakon porođaja (kolostrum), zatim od 5-14. dana nakon porođaja i u zrelom HM uzorkovanom nakon 21. dana od porođaja. Kriterijum za isključivanje iz studije je bio prekidanje laktacije, potreba za primenom terapije koja je kontraindikovana za vreme laktacije, kao i pušenje duvana...

Preterm infants are especially exposed to oxidative stress because of poorer antioxidative defense mechanism. Oxidative stress is induced by frequent infections, as well as by high oxygen concentrations, phototherapy and intravenous lipid infusions, all of which are part of necessary therapy in this population of children. Human milk (HM) represents a complex biological fluid with antioxidative properties. Antioxidative enzymes of HM are superoxide-dismutase (SOD), catalase (CAT), glutathione-peroxidase (GSH-Px), glutathione-reductase (GR). Non enzyme antioxidants in HM are vitamin C, vitamin E, beta-carothen, glutathione, lactoferrin, coenzyme Q, beta-endorphins, and others. Human milk nutrition in preterm infants has an important role in prevention of oxidative stress. Goal: Determination of total antioxidant capacity (TAC) of milk of mothers of preterm infants during lactation period (colostrums, early milk, mature milk). TAC of mature fresh milk is determined and compared with milk exposed to thermal processing (refrigeration, freezing or pasteurization), with fortified HM, and preterm milk formula. Antioxidative status of mature fortified milk and preterm milk formula was also compared. Material and methods: This cohort study included 30 mothers of preterm infants (delivery before 37 weeks of gestation), with lactation according to admission in Institute for neonatology, during the period from December 1st 2014. to May 31st 2016. Sample of HM were collected from each mother three times. The TAC was determined in fresh HM collected in the first 3 days after delivery (colostrum), then between days 5 and 14 after the delivery, and in mature HM after 21 days from the delivery. Criteria for exclusion were cessation of lactation, need for therapy contraindicated during breast feeding and smoking. Determination of TAC in HM was performed by different non-enzyme: spectrophotometric (ability of catching DPPH radicals, determination of total phenol content with Folin-Ciocaletu reagent, method based on antioxidant reaction with Fe (III)-complex, inhibition of lipid peroxidation), electrochemical (cyclic and pulse voltametry), fluorimetric methods (method of determining antioxidative capacity of absorbing oxygen radicals – ORAC), and electron paramagnetic resonant spectroscopy...