Photohemolysis sensitized by the furocoumarin imperatorin and its oxyfunctionalized derivatives

• Published in: Photochemistry and photobiology 1999-04, Vol.69 (4), p.410-420
• Main Authors: Potapenko AYa, Kyagova, A A, Andina, E S, Zhuravel, N N, Lysenko, E P, Möller, M, Stopper, H, Adam, W, Saha-Möller, C R
• Format: Article
• Language: English
• Subjects: Darkness; Erythrocytes - drug effects; Erythrocytes - metabolism; Erythrocytes - radiation effects; Furocoumarins - chemistry; Furocoumarins - pharmacology; Hemolysis - drug effects; Hemolysis - radiation effects; Humans; In Vitro Techniques; Oxidation-Reduction; Oxyhemoglobins - drug effects; Oxyhemoglobins - metabolism; Photobiology
• ISSN: 0031-8655; 1751-1097
• DOI: 10.1562/0031-8655(1999)069<0410:PSBTFI>2.3.CO;2

The dark and photosensitized (366 nm) hemolytic effects of imperatorin and its photooxidation products, the hydroperoxides I and II as well as the corresponding alcohol of the hydroperoxide I (imperatorin alcohol), were studied on human erythrocytes. Imperatorin was shown to photosensitize hemolysis, its fluence (D) dependence of the rate of photohemolysis (V) followed the equation V = V0 + aD2 + bD1/2, in which V0 is the dark hemolysis rate and a and b are constants. At fluences below 200 kJ/m2, the main hemolytic contribution derives from the bD1/2 component, which is due to the in situ formation of the imperatorin hydroperoxides, while at fluences higher than 200 kJ/m2, the main contribution corresponds to the aD2 component due to the two-photon damage of cell membranes. Hydroperoxides I and II induce oxyhemoglobin cross-linking, as well as its conversion to methemoglobin and hemichrome. These reactions involve hydroxyl and alkoxy radicals, as the hemolysis and oxyhemoglobin conversion could be inhibited by t-butanol and butylated hydrotoluene. For comparison, the dark hemolytic effect of the imperatorin alcohol was approximately 10-fold less than of the hydroperoxides.