Malondialdehyde levels can be measured in serum and saliva by using a fast HPLC method with visible detection

Oxidative stress appears when the amount of free radicals that are formed in a living organism exceed its spin-trapping ability. One of the most dangerous free radicals that are formed in the human body is the hydroxyl radical. It can alter several biomolecules, including the unsaturated fatty acids; this process is known as lipid peroxidation and can lead to cell necrosis and generation of several harmful byproducts including malondialdehyde, which serves also as a biomarker of oxidative stress. A new HPLC method with visible detection was developed for the detection of malondialdehyde in human serum and saliva samples. The method was verified in terms of specificity, linearity, limits of detection (0.35 ng/ml), limit of quantification (1.19 ng/ml), recovery (90.13+/-10.25 - 107.29+/-14.33) and precision (3.84+/-1.49% - 6.66+/-1.76%). An analysis time of only 1 minute was obtained and no interferences from the matrices were observed. Statistical analysis (Pearson correlation test) showed a moderate correlation (R = 0.5061, p = 0.0099) between serum and saliva concentrations (N = 25). The possibility of measuring salivary concentrations of malondialdehyde extents the applications of oxidative stress/lipid peroxidation estimations to categories of population unreachable before (pregnant women, small children, etc); repeated sample studies are also easier to make.