| ObjectiveThe purpose of the present study was to evaluate the influence of biochemical markers of cardiac function on pharmacokinetic parameters of Shaji extract by non-compartment model and investigate the pharmacokinetic characteristics of quercetin, kaempferid and isorhamnetin in normal and myocardial ischemic rats. In particular, we wanted to investigate whether there was a relationship between the efficacy enhanced or weakened of Shaji extract and the pharmacokinetic characteristics of quercetin, kaempferid and isorhamnetin under normal physiological or pathological states in rats.MethodsFirstly, the contents of quercetin, kaempferid and isorhamnetin in Shaji extract were determined by HPLC according to the method of Chinese Pharmacopoeia (2010 Edition).Secondly, the method for the determination of quercetin, kaempferid and isorhamnetin in rat’s plasma by HPLC was established.Thirdly, to establish a rat myocardial ischemia model of high survival rate through improving coronary artery ligation method. Then the animals were divided into two groups:normal control group and model group. After an intragatrical administration of Shaji extract, the biochemical indicators and the pharmacokinetic data were collected.Finally, the pharmacokinetic parameters were calculated through DAS 2.0 software. In addition, we established the final compartment model for quercetin, kaempferid and isorhamnetin, and to elucidate the influence of myocardial ischemia on the pharmacokinetic parameters of these three flavonoids in rats.ResultsFirstly, the content of quercetin, kaempferid and isorhamnetin in Shaji extract were 0.3052%,0.04681% and 0.3633%. The content of quercetin, kaempferid and isorhamnetin in Hippophae rhamnoides L. were 0.3831% ,0.05873% and 0.4560%.Secondly, a sensitive, convenient, reliable HPLC-MS/MS detection assay was established for the determination of quercetin, kaempferid and isorhamnetin in rat plasma.Thirdly, compared with the normal control group, not only the electrocardiogram ΔST level and myocardial infarct area, but also the concentration of CK and LDH was significantly increased in myocardial ischemia model group. Results of HE staining showed that:edema, necrosis, myofilament fracture, chronic inflammatory cell infiltration and connective tissue proliferation were found in the myocardial tissues of myocardial ischemia model group rats.Finally, the Cmax and AUC of these three flavonoids were isorhamnetin> quercetin> kaempferid at the same physiological and pathological state; Myocardial ischemia model group failed to detect kaempferide; Compared with the normal group, the Tmax of quercetin, isorhamnetin were significantly increased, while the Ka and Cmax were significantly decreased in myocardial ischemic rats; The t1/2β and MRT0-t of these three flavonoids had no significant difference between the normal and model group.ConclusionFirstly, rat myocardial ischemia model was established successfully.Secondly, after single oral dose of Shaji extract, the pharmacokinetic characteristics of these three flavonoids were fitted to rapid obsorption (especially quercetin), rapid distribution and slow elimination and were eliminated as first-order kinetics. Overall, quercetin、kaempferid may be metabolized to isorhamnetin when absorbed in the body. In setting drug dose, the pathological state of myocardial ischemia could significantly inhibit the absorption rate and degree for effective components of Shaji extract in the body, and less affecting on elimination.Finally, cardiac function changes, vascular endothelial cell permeability changes may be the important factors in causing Shaji extract to generate pharmacokinetic behavior differences in the state of chronic ischemic cardiovascular disease. |
