Co-administration of melatonin reverses the Tin-protoporphyrin (SnPP) induced decline of Cytochrome P450 content in vivo in rats

Melatonin (N-acetyl-5 methoxytryptamine) is a low molecular weight antioxid ant and is an endogeneous defence system against the deleterious actions of the extremely reactive hydroxyl radical. Among the enzymes that participat e in the antioxidant functions is cytochrome P-450, a stalwart of the detox ification system in the body. Our results revealed that tin-protoporphyrin administration brought about a marked decline in cytochrome P-450 levels. T his decline was, however, reversed by the coadministration of the antioxida nt, melatonin. Thus, the enhanced antioxidant status in melatonin-treated r ats may act as a protective mediator of various pharmacological functions a ltered during tin-protoporphyrin (an antihyperbilirubemenic agent) administ ration to Wistar rats.