Pharmacokinetic–pharmacodynamic modeling of the active components of Shenkang injection in rats with chronic renal failure and its protective effect on damaged renal cells

The study aimed to explore the pharmacokinetic and pharmacodynamic alterations of the active components of Shenkang injection (i.e. hydroxy saffron yellow pigment A [HSYA], tanshinol, rheum emodin, and astragaloside IV) in rats with chronic renal failure (CRF), and establish a pharmacokinetic–pharmacodynamic model (PK-PD model) in order to provide a scientific and theoretical basis for the rational clinical use of Shenkang injection. Sprague–Dawley (SD) rats were randomly divided into a normal group, model group, and Shenkang injection group. A rat model of CRF was induced by adenine gavage and then followed by drug administration via tail vein injection. Orbital blood was collected at different timepoints and the blood concentrations of the four active components were measured by UHPLC-Q-Orbitrap HRMS. Serum levels of creatinine (Scr), urea nitrogen (BUN), and uric acid (UA) were determined using an automatic biochemical analyzer. A PK-PD model was established, and DAS 3.2.6 software was used for model fitting as well as statistical analysis. TGF-β1 was utilized to induce normal rat kidney cells to construct a renal fibrosis model to investigate the protective effect of the pharmacological components on renal fibrosis. The pharmacokinetic analysis of hydroxy saffron yellow pigment A, tanshinol, rheum emodin, and astragaloside IV based on UHPLC-Q-Orbitrap HRMS was stable. The linear regression equations for the four active components were as follows: Y = 0.031X + 0.0091 (R² = 0.9986) for hydroxy saffron yellow pigment A, Y = 0.0389X + 0.164 (R² = 0.9979) for tanshinol, Y = 0.0257X + 0.0146 (R² = 0.9973) for rheum emodin, and Y = 0.0763X + 0.0139 (R² = 0.9993) for astragaloside IV, which indicated good linear relationships. The methodological investigation was stable, with the interday and intraday precision RSD <10%. Meanwhile, the recoveries ranged between 90% and 120%, in accordance with the requirements for in vivo analysis of drugs. Compared with the model group, the levels of Scr, BUN, and UA were significantly decreased after 20 min in the Shenkang injection group (p < 0.01). The PK-PD model showed that the four active components in the Shenkang injection group could fit well with the three effect measures (i.e. Scr, BUN, and UA), with the measured values similar to the predicted values. The cell model of renal fibrosis showed that the connective tissue growth factor and FN1 protein expression levels were significantly lower in the Shenkang injection group than those in the model group, and the cell fibrosis was improved. The established method for in vivo analysis of Shenkang injection was highly specific, with good separation of the components and simple operation. The total statistical moment could well integrate the pharmacokinetic parameters of the four active components. After treatment with Shenkang injection, all indexes in the administered group improved and showed significant inhibition of renal cell fibrosis in vitro. This study could provide scientific reference ideas for the clinical rational use of traditional Chinese medicine.