Nickel-induced plasma lipid peroxidation and effect of antioxidants in human blood:: Involvement hydroxyl radical formation and depletion of α-tocopherol

To provide evidence for the oxidative effect of nickel (Ni) treatment on blood, lipid peroxidation (LPO) and hydroxyl radical (.OH) generation were examined in human plasma. Nickel chloride induced LPO in plasma of human blood in vitro in a concentration-dependent (0-10 mM) and time-dependent (0-2 h) manner. The .OH production in plasma was quantified by measurement of conversion of salicylic acid (SA) into its hydroxylated products, 2,3- and 2,5-dihydroxybenzoate (DHB), The concentrations of 2,3- and 2,5-DHB in plasma increased in a concentration-dependent manner after Ni treatment for 1 h. Furthermore, a decreasing trend in alpha-tocopherol levels in plasma was observed after Ni treatment. Concurrent incubation with gluthathione (GSH), catechin (CTCH), and mannitol decreased lipid peroxidation and reduced .OH formation induced by Ni, but exacerbation of the decrease of alpha-tocopherol in plasma occurred with catechin.