Comparative pharmacokinetic analysis of six major bioactive constituents using UPLC-MS/MS in samples isolated from normal and diabetic nephropathy rats after oral administration of Gushen Jiedu capsule.

Berberine, palmatine, physcion, rhein, calycosin-7-O-glucoside, and ferulic acid are six major active consituents that are present in Gushen Jiedu capsule (GSJD) extracts. The aim of this study was to determine the pharmacokinetics of the six active consituents in vivo by a rapid, sensitive, and precise UPLC-MS/MS method, which were compared between normal and diabetic nephropathy (DN) rats. Good separation of the target analytes and internal standards (ketoprofen and puerarin) was obtained on a Waters BEH C18 UPLC column with a mobile phase of 0.1 % formic acid acetonitrile-0.1 % formic acid water. All the calibration curves showed good linearity with a regression coefficient (r2) of ≥ 0.9908. The lower limits of quantification (LLOQ) for berberine, palmatine, physcion, rhein, calycosin-7-O-glucoside, and ferulic acid were 20, 2.5, 20, 20, 2.5, and 2.5 ng/mL, respectively. The relative standard deviations (RSDs) of intra-day and inter-day precision were all within 12.66 %, and the relative errors of intra-day and inter-day accuracy ranged from - 15.00 to 14.93 %. Good extraction recovery and matrix effects were obtained. The stability study confirmed the stability of the six analytes (RSD < 15 %). Finally, the data showed that the pharmacokinetic parameters (especially CLz/F, AUC and Tmax) of the six target analytes in DN rats were significantly different from those in normal rats. PK studies under pathological conditions could provide new thoughts to elucidate the underlying mechanism of GSJD and promote the clinical development of GSJD to treat DN.