Isolation and identification of metabolites of bakuchiol in rats.

Bakuchiol, the main active component of Psoralea corylifolia, showed a range of significant pharmacological activities, including antimicrobial, antiinflammatory, reduction of bone loss and estrogenic activities. In this research, 12 metabolites, including 11 new compounds, were isolated from the urine and feces of rats after oral administration of bakuchiol, and their structures were elucidated by extensive spectroscopic analysis. The possible metabolic pathways of bakuchiol in rats were proposed, and a rare bile acid conjugation reaction was found. In addition, bakuchiol and its metabolites M1-M3 were studied for their alkaline phosphatase (ALP) activities on MC3T3-E1 cells and cytotoxicity on HKC-8 cells. The data showed that bakuchiol exerted significant effects on ALP activity of MC3T3-E1 cells and cytotoxicity on HKC-8 cells, while M1-M3 only showed ALP activities at 10(-5)M on MC3T3-E1 cells and no cytotoxicity on HKC-8 cells.