Comparative pharmacokinetics of nine major bioactive components in normal and ulcerative colitis rats after oral administration of Lizhong decoction extracts by UPLC-TQ-MS/MS

Lizhong decoction (LZD), a classic formula, has been used to treat ulcerative colitis (UC) for thousands of years in clinical practice. However, the pharmacokinetic characteristics of its major bioactive components in rats under different physiological and pathological states are not clear. Thus, in this study, a rapid and sensitive analytical method, ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS/MS) method, was developed and applied to simultaneously determine glycyrrhizic acid, liquiritin, isoliquiritin, glycyrrhizin, isoliquiritigenin, 6-gingerol, ginsenoside Rg1, ginsenoside Rb1 and ginsenoside Re in normal and UC rats after oral administration of LZD extract. A Waters BEH C-18 UPLC column was used for chromatographic separation, while acetonitrile and 0.1% formic acid were selected as mobile phase. The linearity of nine analytes was >0.9920. Inter- and intra-day accuracy was <= 11.4% and precision was from 1.1 to 12.7%. Additionally, stable and suitable extraction recoveries were also obtained. The established method was validated and found to be specific, accurate and precise for nine analytes. Furthermore, it was successfully applied to the pharmacokinetic investigation of nine major components after oral administration of LZD extracts to normal and model rats, respectively. The results showed that the pharmacokinetic parameters (C-max, T-max, AUC(0-t), AUC(0-infinity)) in the plasma of UC rats were significantly different from those of normal rats, which could provide a reference for the clinical application of LZD.