Quzhou Fructus Aurantii (QFA) is an herb that is commonly used to alleviate inflammation in individuals dealing with obesity.To date, however, no systematic pharmacokinetic (PK) or pharmacodynamic (PD) analyses of the clinical efficacy of QFA under hyperlipemia-associated oxidative stress conditions have been conducted. The present study, was therefore designed to construct a PK-PD model for this herb, with the goal of linking QFA PK profiles to key therapeutic outlines to guide the therapeutic use of this herb in clinical settings.

Rats were fed a high-fat diet in order to establish a model of hyperlipidemia, after which they were randomized into a normal control group (NCG), a normal treatment group (NTG), a model control group (MCG), and a model treated group (MTG) (n = 6 each). QAF decoction was used to treat rats in the NTG and MTG groups (25 g/kg), while equivalent volumes of physiological saline were administered to rats in the NCG and MCG groups. Plasma samples were collected from the mandibular vein for animals at appropriate time points and analyzed via high-performance liquid chromatography (HPLC). We evaluated PK properties for three QAF components and compared these dynamics between the NTG and MTG groups, while also measuring levels of lipid peroxidation (LPO) in the plasma of rats in all four treatment groups. We then constructed a PK-PD model based upon plasma neohesperidin, luteolin, and nobiletin concentrations and LPO levels using a three-compartment PK model together with a Sigmoid   PD model. This model thereby enabled us to assess the antioxidative impact of neohesperidin, luteolin, and nobiletin on hyperlipidemia in rats.

When comparing the NTG and MTG groups, we detected significant differences in the following parameters pertaining to neohesperidin, luteolin, and nobiletin: , V1,  , CL1 (p < 0.01) and AUC_0-t,  ,   (p < 0.05). Relative to NTG group rats, AUC_0-t,   and   values significantly higher for MTG group rats (p < 0.01), while  , V1, and   values were significantly lower in MTG group rats (p < 0.01) in MTG rats. QAF decoction also exhibited excellent PD efficacy in MTG rats, with significant reductions in plasma LPO levels relative to NTG rats (p < 0.01) following treatment. This therapeutic efficacy may be attributable to the activity of neohesperidin, luteolin, and nobiletin, as LPO levels and plasma concentrations of these compounds were negatively correlated in treated rats. Based upon Akaike Information Criterion (AIC) values, we determined that neohesperidin, luteolin, and nobiletin PK processes were consistent with a three-compartment model. Together, these findings indicated that three active components in QAF decoction (neohesperidin, luteolin, and nobiletin) may exhibit antioxidant activity in vivo.

Our in vivo data indicated that neohesperidin, luteolin and nobiletin components of QAF decoctions exhibit distinct PK and PD properties. Together, these findings suggest that hyperlipidemia-related oxidative stress can significantly impact QFA decoction PK and PD parameters. Our data additionally offer fundamental insights that can be used to design appropriate dosing regimens for individualized clinical QAF decoction treatment.