Lipid Peroxidation in Pigmented and Unpigmented Liver Tissues: Protective Role of Melanin


  • A preliminary report was presented to the 32nd National Meeting of the Italian Society for Biochemistry, September 28-October 1, 1986, abstract n. V-10.

Address reprint requests to Prof. Giovanni Sichel, Istituto di Biologia generale, Via Androne 81, 95124 Catania, Italy.


The protective role of melanin as an antioxidant biopolymer against lipid peroxidation was investigated. In pigmented frog liver and in albino rat liver the following were tested: thiobarbituric acid (TBA) reactive material (to show the induced lipoperoxidation in vitro), fatty acids, and reduced glutathione content. Our results show that susceptibility to the in vitro lipoperoxidation induced by ferrous ions is lower in the tissue containing melanin, though the content of the polyunsaturated fatty acids is higher in pigmented than in unpigmented tissues and reduced glutathione levels are lower in pigmented tissue. Our data support the hypothesis that melanin could reduce lipoperoxidation in pigmented tissue.