Pharmacokinetics, biodistribution and bioavailability of isoliquiritigenin after intravenous and oral administration

Context: Isoliquiritigenin (ISL) has been shown to exhibit a variety of biological activities. However, there is little research on the pharmacokinetic behavior and tissues distribution of ISL. Objective: Pharmacokinetics, biodistribution and bioavailability of ISL after intravenous and oral administration were determined by systematic investigation in Sprague-Dawley rats. Materials and methods: ISL was dissolved in medicinal ethanol-Tween 80-0.9% sodium chloride saline in a volume ratio of 10:15:75. The ISL solution was injected in rats via a tail vein at a single dose of 10, 20 and 50 mg/kg and administered orally in rats at a single dose of 20, 50 and 100 mg/kg, respectively. Blood samples were collected at time intervals of 0.08, 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 6, 8 and 12 h after intravenous injection. Tissues of interests in mice were collected immediately at each determined time point (0.5, 1, 2, 3 and 6 h) after cervical dislocation. Results: The dose-normalized AUC values were 7.3, 7.6 and 8.7 mu g x h/ml (calculated based on the dose of 10 mg/kg) for intravenous doses of 10, 20 and 50 mg/kg, respectively. The elimination half-lifes (t(1/2 lambda)) were 4.9, 4.6 and 4.8 h at 10, 20 and 50 mg/kg intravenous doses, respectively. The F values were 29.86, 22.70, 33.62% for oral doses of 20, 50 and 100 mg/kg, respectively. Liver, heart and kidney were major distribution tissues of ISL in mice. The plasma protein binding of ISL in rats was 43.72%. Conclusion: The work may useful for further study of the bioactive mechanism of ISL.