N-acetyl-serotonin reduces copper (I) ion-induced lipid peroxidation in bovine retinal homogenates

Purpose: Chalcosis is an ocular condition caused by penetration injury of c opper or its alloy, which leads to extensive ocular inflammation. N-acetyt- serotonin has recently been identified as a potent antioxidant against free radical stress. In this study, we determined the efficacy of N-acetyl-sero tonin against the copper (I)-induced retinal lipid peroxidation. Methods: Copper (I)-treated (100 muM) bovine retinal homogenates were incub ated with 6 different concentrations (i.e. 0.00, 0.25, 0.50, 1.00, 2.00 and 4.00 mM) of N-acetyl-serotonin or vitamin E, The malondialdehyde level was measured as an index of lipid peroxidation. Results: Copper (I) ions induced a significant dose-dependent increase in m alondialdehyde (p = 0.007), Co-incubation with N-acetyl-serotonin or vitami n E significantly suppressed the copper (I)-induced malondialdehyde product ion (p<0.0001), The concentration to inhibit 50% of damage for N-acetyl-ser otonin and vitamin E were found to be 1.54 mM and 0.45 mM, respectively. Conclusion: Although N-acetyl-serotonin is only 29% as effective as vitamin E in suppressing the copper (I)-induced lipid peroxidation, the present st udy supports a pharmacological potential of N-acetyl-serotonin combating fr ee radical oxidative damages in the ocular tissues.