Labeling of Phalerin With Iodium-131 and Biodistribution Study in Inflamed Mice

Phalerin is an active component of mahkota dewa (Phaleria macrocarpa (Scheff.) Boerl) which has been proven to have an anti inflammation effect. Labeling with gamma emitting radionuclides is aimed to study its pharmacokinetic behaviour particularly to trace its metabolites. Labeling of phalerin with 131I using iodogen as oxidator has been carried out. Radiolabeled compound was characterised using High Performance Liquid Chromatography (HPLC) eluted with methanol 70% and thin layer chromatography (TLC) eluted with chloroform-methanol (9:2) whereas labeling efficiency was determined using the same TLC system. Purification of radiolabeled product was carried out using size exclusion chromatography (Sephadex G-25 column) eluted with 0,05 M phosphate buffer pH 7,4. Biodistribution of radiolabeled compound in various organs of normal and inflammation induced mice was observed at 1, 4 and 24 hours post injection. Labeling efficiency of 131I-phalerin was 90,2 ± 2,8% and increased to 96,0 ± 0,4% after purification. Target to non-target ratio of radiolabeled phalerin at 1, 4 and 24 hours were 69,2; 26,4; dan 4,7% respectively. The results showed a significant uptake of radiolabeled phalerin in inflamed tissue. (author)