Comparative intestinal bacteria-associated pharmacokinetics of 16 components of Shengjiang Xiexin decoction between normal rats and rats with irinotecan hydrochloride (CPT-11)-induced gastrointestinal toxicity in vitro using salting-out sample preparation and LC-MS/MS†
Shengjiang Xiexin decoction (SXD) exerts protective effects against gastrointestinal injury induced by irinotecan hydrochloride (CPT-11). The intestinal bacteria-associated in vitro pharmacokinetics of 16 components of SXD in normal rats and those with CPT-11-induced gastrointestinal toxicity were compared in this study. A sensitive and reproducible ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantification of 16 components of SXD in a rat intestinal bacteria incubation system, using naringin, naringenin and tetrahydropalmatine as internal standards (ISs). The samples were prepared via salting-out assisted liquid–liquid extraction (SALLE) with NaCl to reduce matrix effects. Chromatographic separation was performed on a sub-2 μm analytical column with acetonitrile and 0.1% aqueous formic acid as mobile phase. All of the analyzed components and ISs were detected via multiple reaction monitoring (MRM) scanning with electrospray ionization. The proposed method was successfully applied for the in vitro pharmacokinetic analysis of the multiple components of a complex mixture consisting of a traditional Chinese medicine (TCM) and an intestinal bacterial incubation system. The pharmacokinetic parameters of some flavonoid glycosides and aglycones in the rats with CPT-11-induced gastrointestinal toxicity were significantly different (p < 0.05, p < 0.01) from those in the normal rats, which suggested that consumption of CPT-11 could qualitatively and/or quantitatively alter the intestinal bacteria as well as the metabolic activities of enzymes. The in vitro pharmacokinetic analysis of these components in the intestinal bacterial incubation system provided valuable information for achieving a deeper understanding of the mechanisms involved in the alteration of intestinal bacteria induced by CPT-11 and further in vivo pharmacokinetic research on SXD. The intestinal bacteria-based pharmacokinetic method could benefit the study of interactions between TCMs and chemical drugs in clinical use.