Evaluation of the influence of sulfur fumigation on the pharmacokinetics of four active ingredients in Si Wu Tang.

Sulfur fumigation may induce the decrease or the chemical transformation of some active ingredients of traditional Chinese medicines in vitro. Whether sulfur fumigation can cause the pharmacokinetic changes of the active ingredients in vivo is related to the efficacy and the safety of Chinese medicines' application clinically. A sensitive, specific, and accurate method for the simultaneous determination of paeoniflorin, ferulic acid, senkyunolide A, and senkyunolide I in rat plasma by ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry was developed to evaluate the influence of sulfur fumigation to Si Wu Tang for the first time. Each compound was extracted from plasma samples by liquid-liquid extraction with ethyl acetate, and the chromatographic separation was accomplished on an Agilent Extend C18 column with a linear gradient elution. The mass spectrometric detection and analysis were performed by using an AB Sciex triple quadrupole 5500 mass spectrometer in multiple reaction monitoring mode. The validated method was successfully applied to a pharmacokinetic study of four compounds in rats after oral administration of sun-dried and sulfur-fumigated Si Wu Tang. The results provided a meaningful basis for evaluating the affection of sulfur fumigation to the clinical application and the efficacy of Si Wu Tang.