[Integrated pharmacokinetic study of multiple effective components of tea polyphenols and its correlation with...

LC-MS/MS method was used to simultaneously determine anti-oxidative active catechins EGCG, ECG, EGC and EC in plasma of rats treated with tea polyphenols (TP). The integrated plasma concentration (C') of TP was calculated by means of self-defined weighing coefficient based on percent AUC of individual components, thereby assessing integrated pharmacokinetic (PK) parameters of TP via log C'-T curve. The anti-free radical effects of TP were estimated using inhibitory rate of drug-containing serum collected at different times from rats against in vitro lipid peroxidation of mouse liver homogenate. The obtained E-T curves were used to calculate anti-free radical pharmacodynamic (PD) parameters of TP. E-logC and E-log C' plots and linear regression were carried out in order to obtain the correlation coefficient (R2). The results indicated that the log C'-T curves of TP, which could be best described by three-compartment model, corresponded to elimination rule of iv administration of drugs. The integrated PK parameters showed that TP was distributed in body rapidly and widely, and eliminated from deep compartment slowly. From comparison of R2 values and consistence of C'-T course and E-T course, it was evident that TP integrated PK behaviors correlated much better with its PD behaviors than individual active components, and thus demonstrated that integrated PK parameters could characterize to maximal extent holistic disposition of Chinese herbal drugs and reflect residence properties of holistic effective substances in biological body.