ABSTRACT
The present study is to investigate the absorption characteristics of the main components in Polygonum orientale extract in normal and isoproterenol-induced myocardial ischemia model rats with everted intestinal sac models. Intestinal sac fluid samples were collected in different part of intestine(duodenum, jejunum, ileum, colon) at different time after administration of different concentration of P. orientale extract(5.0,10.0, 20.0 mg·mL~(-1)). An UPLC-TQD method was employed for the determination of six components including orientin, isoorientin, vitexin, protocatechuic acid, kaempferol-3-O-β-D-glucoside and quercitrin in the intestinal sac samples. The absorption rate and cumulative absorption were calculated to analyze the intestinal absorption characteristics of six components in normal and myocardial ischemia model rats. The P-glycoprotein(P-gp) inhibitor was applied to investigate influence of intestinal absorption of six components in P. orientale extract. The results showed that the main absorption sites were concentrated on the duodenum at low concentration, while they were the colon at the medium concentration and the ileum at high concentration in control groups. In the condition of myocardial ischemia model, the main absorption sites focus on the ileum and jejunum at low concentration; the main absorption sites were in the ileum at the medium concentration and main absorption sites were the duodenum and ileum at high concentration. Compared with the normal group, the absorption rate and cumulative absorption of the six components significantly decreased in the model group. P-gp inhibitor markedly increased the absorption rate and cumulative absorption of six components in the model group, inferring that the 6 components may be the substrates of P-gp, and the mechanism needs further study. In this study, it is revealed that the six components of P. orientale extract can be absorbed into the intestinal sac, and it is an effective method to assess the intestinal absorption characteristics of P. orientale extract through everted intestinal sac model, providing data support for the clinical application and further development of P. orientale.
Subject(s)
Animals , Rats , Intestinal Absorption , Intestines , Isoproterenol , Myocardial Ischemia/chemically induced , Polygonum , Rats, Sprague-DawleyABSTRACT
OBJECTIVE： To study the protective effects of Polygonum orientale extract on myocardial ischemia-reperfusion injury （MIRI） model rats， and to provide reference for it’s deeply development of medicinal source. METHODS： Totally 24 rats were randomly divided into sham operation group （normal saline）， model group （normal saline）， Compound danshen tablet group （positive group， 0.17 g/kg） and P. orientale extract group （86 g/kg， calculated by crude drug）， with 6 rats in each group. All groups were given drugs 2 mL/100 g intragastrically once a day. After 4 d of consecutive administration， MIRI model was induced by the left anterior descending branch of arteria coronaria in all groups except for sham operation group. 24 h after reperfusion， they were given related medicine again. After medication， the changes of electrocardiogram ST segment were monitored in each group. The plasma levels of LDH， CK-MB， CK， cTn-I， SOD and NO were detected in each group. The myocardial infarction rate in each group was calculated and the pathomorphological changes in the myocardium were observed. RESULTS： Compared with sham operation group， ST segment of myocardial electrocardiogram was increased in model group （P＜0.01）. The plasma levels of LDH， CK， CK-MB and cTn-I were increased significantly （P＜0.01）， while the plasma levels of SOD and NO were decreased significantly （P＜0.01）. The rate of myocardial infarction was increased significantly （P＜0.01）， and pathomorphological changes were observed in myocardial tissue such as infiltration of inflammatory cells and loose cytoplasm of cardiac myocytes. Compared with model group， ST segment of myocardial electrocardiogram was decreased significantly in Compound danshen tablet group and P. orientale extract group （P＜0.05）； the plasma levels of LDH， CK， CK-MB and cTn-I were decreased significantly （P＜0.05）， while the plasma levels of SOD and NO were increased significantly （P＜0.05）； the rate of myocardial infarction was decreased significantly （P＜0.05）， and inflammatory cell infiltration and tissue edema in myocardium were relieved to varying degrees. CONCLUSIONS： The protective effect of P. orientale extract protect on MIRI may be exerted by anti-oxidative damage.