Pharmacokinetics, Bioavailability, Tissue Distribution, Excretion, and Metabolite Identification of Methoxyflavones in Kaempferia parviflora Extract in Rats

Kaempferia parviflora (KP) is an herbal plant in the family of Zingib-eraceae. KP mainly contains methoxyflavones, especially 5,7-dime-thoxyflavone (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, distribu-tion, 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 pharmacoki-netic parameters of PMF, TMF, and DMF. For distribution and excre-tion 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 quanti-fied by high-performance liquid chromatography-UV, and the metab-olites in urine and feces were further identified by using liquid chro