PT - JOURNAL ARTICLE AU - Catheleeya Mekjaruskul AU - Michael Jay AU - Bungorn Sripanidkulchai TI - Pharmacokinetics, Bioavailability, Tissue Distribution, Excretion, and Metabolite Identification of Methoxyflavones in <em>Kaempferia parviflora</em> Extract in Rats AID - 10.1124/dmd.112.047142 DP - 2012 Dec 01 TA - Drug Metabolism and Disposition PG - 2342--2353 VI - 40 IP - 12 4099 - http://dmd.aspetjournals.org/content/40/12/2342.short 4100 - http://dmd.aspetjournals.org/content/40/12/2342.full SO - Drug Metab Dispos2012 Dec 01; 40 AB - Kaempferia parviflora (KP) is an herbal plant in the family of Zingiberaceae. KP mainly contains methoxyflavones, especially 5,7-dimethoxyflavone (DMF), 5,7,4′-trimethoxyflavone (TMF), and 3,5,7,3′,4′-pentamethoxyflavone (PMF). The present study was designed to characterize the pharmacokinetics, including bioavailability, distribution, excretion, and identification of metabolites after administration of a KP ethanolic extract. Male rats were orally or intravenously administered a 250 mg/kg concentration of a KP extract, and blood samples were obtained at selected times to determine pharmacokinetic parameters of PMF, TMF, and DMF. For distribution and excretion studies, the organs, urine, and feces samples were collected at various times after oral administration of a larger (750 mg/kg) dose of KP extract. Methoxyflavones in the biological samples were quantified by high-performance liquid chromatography-UV, and the metabolites in urine and feces were further identified by using liquid chromatography-tandem mass spectrometry. After oral administration, concentrations of the three methoxyflavones quickly approached their maximal concentration, ranging from 0.55 to 0.88 μg/ml within 1 to 2 h after administration, and then were gradually excreted with half-lives of 3 to 6 h. The methoxyflavones showed low oral bioavailability of 1 to 4%. Three methoxyflavones were detected at their highest levels in liver followed by kidney. They were also found in lung, testes, and brain. After absorption, organ distribution, and metabolism, the components of KP were mainly eliminated through urine in the forms of demethylated, sulfated, and glucuronidated products and as demethylated metabolites in the feces. The parent compounds were found to have 0.79, 1.76, and 3.10% dose recovery in urine and 1.06, 1.77, and 0.96% dose recovery in feces for PMF, TMF, and DMF, respectively. These studies are the first to describe the pharmacokinetics of KP extract to provide the information on blood and tissue levels.