Absolute bioavailability, pharmacokinetics and excretion of 5,7,3′,4′-tetramethoxyflavone in rats

The compound 5,7,3′,4′-Tetramethoxyflavone (TMF) is one of the major methoxyflavones identified in Kaempferia parviflora with several bioactivities, such as anti-allergic activity, antifungal and anti-inflammatory effects; however the information on oral bioavailability, pharmacokinetics and excretion of TMF is still absent. This study is designed to investigate the bioavailability, pharmacokinetics, and excretion of TMF in rats. After oral administration of 50 mg/kg TMF, the Cmax, Tmax, and T1/2 were calculated as 0.79 ± 0.30 μg/ml, 190.34 ± 24.50 min, and 273.76 ± 90.23 min, respectively. The bioavailability of TMF was estimated as 14.3% based on the AUCs of oral and IV administration. In excretion study, up to 48 h, 0.81% of the oral administered TMF was excreted as unconverted form fecal excretion and 0.05% from urinary excretion; it suggested that TMF mainly excreted as the metabolites form. The data presented in this study could provide useful information for the clinical applications of TMF in the future.