Abstract
Naringin (CAS 10236-47-2), a flavanone glucoside widely present in fruits of citrus
plants, has received extensive studies on its potential effects on health benefits
and was recently demonstrated to be a putative antitussive. In this study, we determined
the tissue distributions of naringin and its metabolites (naringenin and naringenin’s
conjugates) in rats to examine whether they undergo selective uptake by specific organs.
Naringin was administered orally to rats at the dose of 42 mg/kg and the concentrations
of naringin and its metabolites in tissue compartments were determined by liquid chromatography-tandem
mass spectrometry (LC-MS/MS). The areas under curve values in the individual tissues
decreased as follows: stomach, small intestine, liver, trachea, muscle, kidney, lung,
fat, heart, spleen, ovary, testis, brain for naringin; and liver, stomach, small intestine,
kidney, trachea, lung, testis, heart, ovary, fat, spleen, muscle, brain for total
naringenin (including free and its conjugates). Naringin and total naringenin were
rapidly and widely distributed to all the tissues except brain in rats. They had difficulties
in crossing the blood-brain barrier. There are no accumulations in rats. This study
identifying naringin in several organs including lung and trachea may explain its
effects as antitussive.
Key words
antitussive - naringin - naringenin - tissue distribution - LC-MS/MS - rats
