Biomarkers of oxidative stress derived damage to proteins and DNA in human breast milk

Abstract Oxidative stress derived biomarkers have been extensively studied for assessing pathological situations in the neonatal period and their usefulness for an early outcome prediction of oxidative stress related diseases in non-invasive biofluids could be demonstrated. This is the first report on a method for the simultaneous detection of a panel of oxidative stress related biomarkers for quantifying damage to proteins and DNA in human breast milk samples. A straightforward sample clean-up procedure using 1.5 mL of milk was developed and extracts were analyzed by ultra-performance liquid chromatography coupled to tandem mass spectrometry. The analytical method was validated and applied to human milk samples from a cohort of mothers of preterm infants, as well as donor human milk samples before and after pasteurization at a human milk bank. The results demonstrate the feasibility of this method for the analysis of a panel of oxidative stress related biomarkers, reporting ranges found in human milk.