Pharmacokinetic and excretion study of eight active constituents in rat by LC-MS/MS after oral administration of the Toddalia asiatica extract.

Toddalia asiatica L., a significant medicinal plant in the family Rutaceae, has been applied to treat rheumatoid diseases for decades. Its pharmacological activities are mainly attributed to the existence of generous coumarins and alkaloids; however, the pharmacokinetics of Toddalia asiatica L. remain unclear. A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was established for the simultaneous determination of four coumarins, three alkaloids and one flavonoid (hesperidin, nitidine chloride, chelerythrine, toddalolactone, isopimpinellin, pimpinellin, bergapten and dictamnine) in rat feces as well as four coumarins and one alkaloid (toddalolactone, isopimpinellin, pimpinellin, bergapten and dictamnine) in rat plasma and urine. Chromatographic separation was accomplished on an Agilent ZORBAX SB-C18 column (2.1 × 150 mm, 5 μm) with acetonitrile (containing 0.1% formic acid) and 5 mmol/L aqueous ammonium formate for gradient elution. A correlation coefficient greater than 0.9925 reflected the excellent linearity of the analytical response. The lower limits of quantification were 30.0, 10.0, 10.0, 30.0, 5.0, 10.0, 2.5 and 2.5 ng/mL for hesperidin, nitidine chloride, chelerythrine, toddalolactone, isopimpinellin, pimpinellin, bergapten and dictamnine, respectively. The intra- and inter-day precision were less than 12.7%, and the accuracy was between -11.8% and 12.9%. In summary, this study is the first to study the pharmacokinetics and excretion of T. asiatica extract after oral administration, which may provide a scientific basis for its clinical applications.