Role of Lipid Peroxidation in Phototoxic Effects of Tin-Porphyrin in neonatal rats 17

Background: Metalloporphyrine are inhibitors of heme oxygenase enzyme. Tin-protoporphyrin (Sn-PP) is one such compound, which potently supress billirubin production. However Sn-PP is a potential pohotosensitizers and could react with ambient fluorescent lights or sunlight to lead to tissue damage. This effect of Sn-PP may be due to lipid peroxidation. Ain: We investigated the role of lipid peroxidation in Sn-PP mediated photoxicity. Methods: Twenty-two neonatal rats were administered intraperitoneal injections of 40μmol/kg of Sn-PP (4mM). Twelve of them were exposed to sunlight for 3 hours(Group I) and ten of them kept in the dark (Group II) Control group (ten rats) were given injections of equal volume of normal saline (Group III). Blood samples were analyzed for malondialdehyde (MDA) as indices of lipid peroxidation. Results: Mean MDA level was significantly increased in group I (1.4550±0.087) compared with group II(1.0978±0.080) and group III (1.0282±0.057). There was no significant difference in mean MDA level between group II and III (p>0 017)Conclusion: Lipid peroxidation can play a significant role in Sn-PP mediated phototoxicity in neonatal rats.