Characteristic rat tissue accumulation of nobiletin, a chemopreventive polymethoxyflavonoid, in comparison with luteolin.
Nobiletin (NOB), a polymethoxyflavonoid, is an effective anti-inflammatory and chemopreventive phytochemical found in citrus fruits. We compared the absorption and metabolism characteristics of NOB with those of luteolin (LT) in male SD rats. Each flavonoid (67.1 micromol/kg of body weight) was given separately by gastric intubation, and then concentrations were measured at 1, 4, and 24 hours after administration. In the digestive organs, NOB showed a notable tendency for localizing into the mucous membrane and muscularis from 1 to 4 hours, in contrast to LT, though both NOB and LT were completely excreted within 24 hours. Further, significant amounts of NOB were detected in the whole liver and kidney specimens, whereas LT accumulation was slight. Although serum concentrations of NOB from 1 to 4 hours were comparable to those of LT, urinary concentrations of LT were significantly higher from 4 to 24 hours. Following glucuronidase/sulfatase treatments of urinary materials, we detected 3 types of mono-demethylated NOB, including 3'-demethyl-NOB, and two di-demethylated types, as well as 3'-demethyl-NOB alone in serum samples using liquid chromatography-mass spectral analysis. Our results suggest that the metabolic properties of polymethoxyflavonoids are distinct from those of other general flavonoids, because of their wide distribution and accumulation in tissue.
Murakami
Akira
A
Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan. cancer@kais.kyoto-u.ac.jp
Koshimizu
Koichi
K
Ohigashi
Hajime
H
Kuwahara
Shigeru
S
Kuki
Wataru
W
Takahashi
Yasuo
Y
Hosotani
Keisuke
K
Kawahara
Satsuki
S
Matsuoka
Yumi
Y
D000818:Animals; D016588:Anticarcinogenic Agents / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D047309:Flavones; D005419:Flavonoids / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D005753:Gastric Mucosa / Q000737:chemistry; D007420:Intestine, Large / Q000737:chemistry; D007421:Intestine, Small / Q000737:chemistry; D007700:Kinetics; D047311:Luteolin; D008297:Male; D051381:Rats; D013270:Stomach / Q000737:chemistry; D014018:Tissue Distribution
D016588:Anticarcinogenic Agents; D047309:Flavones; D005419:Flavonoids; C008661:nobiletin; D047311:Luteolin