HUMAN CYTOCHROME P-450S ARE PRO-OXIDANTS IN IRON ASCORBATE-INITIATED MICROSOMAL LIPID-PEROXIDATION

We have examined the effect of human cytochrome P-450'S (1A1, 1A2, 3A4 , 2A6, 2B6, 2D6, 2E1) on ascorbate/ iron-induced lipid peroxidation. U sing microsomes prepared from human lymphoblastic cells enriched in re combinant cytochrome P-450 isoenzymes, we have shown that the degree o f peroxidation is a function of the amount of P-450 present rather tha n the presence of any specific isoenzyme. Incorporated P-450 increased the amount of peroxidation products by up to 2.1-fold compared to the control microsomes with no P-450. It is therefore concluded that cyto chrome P-450's play a significant role in ascorbate/iron peroxidation.