Effect of rutin and its copper complex on superoxide formation and lipid peroxidation in rat liver microsomes

Two free radical scavengers, bioflavonoid rutin and the copper-rutin complex Cu(Rut)Cl2, inhibited lucigenin-amplified chemiluminescence and lipid peroxidation in rat liver microsomes, Cu(Rut)Cl2 being a 5–9 times more efficient inhibitor than rutin. The enhanced inhibitory activity of Cu(Rut)Cl2 was due to the presence of the additional superoxide-dismutating center (Cu), as follows from the comparison of its effects on microsomal chemiluminescence and cytochrome c reduction by xanthine oxidase. Similar effects of both inhibitors on superoxide production and lipid peroxidation as well as the elevated activity of Cu(Rut)Cl2 indicate an important role of superoxide ion in the initiation of microsomal lipid peroxidation.