Pharmacokinetic study of puerarin in rats

Pueraria candollei var. mirifica is a medicinal plant which has been promoted as a “Champion Product” by the Government of Thailand. Puerarin, the major bioactive component of this plant, has been an interest of pharmacodynamic activity against aging diseases, but there is little pharmacokinetic information to support further study of this activity. Therefore, the aim of this study was to determine the pharmacokinetics of puerarin, including absorption, distribution, metabolism and elimination, in female rats. Moreover, this is the first study to examine the tissue distribution of puerarin in the hippocampus, femur and tibia, and mammary gland based on recently the pharmacodynamic effects reported for neurodegenerative disease, osteoporosis, and breast cancer, respectively. Adult female rats were administered puerarin at 1 mg/kg intravenously or 5 and 10 mg/kg orally. Blood, tissue, urine and feces were collected and analysed by liquid chromatography-tandem mass spectrometry. Puerarin reached a maximum concentration in blood within 1 h after oral dosing, and had an absolute oral bioavailability of approximately 7%. Puerarin was widely distributed in several tissues, including the hippocampus, heart, lung, stomach, liver, mammary gland, kidney, spleen, femur, and tibia. Approximately 50% of the intravenous dose was excreted as glucuronide metabolites via the urinary route. These results are useful for the development of puerarin and Pueraria candollei var. mirifica as phytopharmaceutical products for the prevention and treatment of aging diseases.