A Rapid Scavenger of the Lipid Peroxidation Product Malondialdehyde: New Perspective of Taurine

The purpose of this study is to check if taurine, as an antioxidant or dietary supplement, can trap MDA (malondialdehyde) indirectly or directly and thereby prevents the formation of advanced lipoxidation end products (ALES) in vitro. Reaction between taurine with fatty acid, verified by detecting the formation and yield of MDA and taurine consumption, shows that taurine may trap reactive intermediates during lipid peroxidation. The direct reaction between taurine and MDA indicates that taurine reacts readily with MDA under supraphysiological conditions to form different products. A nonfluorescent enamine (product 1) and a lipofuscin-like fluorescent 1,4-dihydropyridine (product 2) were obtained experimentally from reaction of equimolar of taurine with MDA and were detected by means of HPLC (high-performance liquid chromatography) separation for the reaction mixtures at ten minutes and 48 h. It was observed that the former was formed much faster than the latter. We suggest a mechanism for both the oxidation process of polyunsaturated fatty acids (PUFA) and the reaction of taurine and MDA. Taurine, as a potent inhibitor of the chemical modification of proteins, also greatly prevents the formation of lipofuscin-like fluorescence induced by the reaction of MDA with bovine serum albumin. The results indicate that the scavenging effects of taurine on reactive carbonyl compounds may play an important role in inhibiting the formation of ALEs and in protecting proteins against carbonyl stress.