| Liver is an important organ that involved in human metabolism,and liver diseases are also the main diseases that leading to death.Radix scutellariae is the dried root of scutellaria baicalensis georgi.It has a good protective effect on liver,It can also significantly hold-up fibrosis and lipid peroxidation of liver in rats.The traditional form of administration is decoction.Baicalin is a kind of flavonoid compound extracted from the traditional Chinese medicine Scutellaria baicalensis Georgi which has various pharmacological effects such as scavenging free radicals,anti-oxidation,anti-inflammatory,and so on,it also has a protective effect on acute liver injury caused by carbon tetrachloride（CCl4）,which can significantly improve chronic liver fibrosis induced by CCl4.It is a potential anti-hepatic fibrosis drug,but it is insoluble in water.The research team produced water-soluble baicalin magnesium salt in the preliminary study,which proved that the baicalin magnesium salt is the original form of baicalin in the traditional Chinese medicine Scutellaria baicalensis,so baicalin magnesium salt is more suitable to represent the pharmacological action of Scutellaria baicalensis.Meanwhile,the pharmacodynamic study showed that the rats were injected with baicalin magnesium salt and baicalin in the tail vein,baicalin magnesium salt has a better protective effect on liver injury induced by CCl4in rats.Compared with injection,the compliance of patients with oral administration is better and easier to be accepted.Therefore,the research group plans to develop the oral system of baicalin magnesium salt with hepatoprotective effect.At present,the research group has completed the pharmacokinetic study that rats were given baicalin magnesium salt by gavage.Follow up literature found that physiological and pathological changes will affect the absorption,distribution,metabolism and excretion of drugs and resulting in significant differences in pharmacokinetic parameters.Moreover,the pharmacokinetic parameters and tissue distribution characteristics of the body are more related to the clinical application of drugs in physiological and pathological state.Therefore,The main purpose of this study is to explore the influence of pharmacokinetics and tissue distribution that rats were gavaged with baicalin magnesium salt under different physiological conditions.Objective:To establish a reliable and accurate high performance liquid chromatography（HPLC）detection method that simultaneous determination of baicalin magnesium salt and baicalein in rat plasma and tissues;to reveal the effect of food on pharmacokinetics of baicalin magnesium salt and liver injury on its pharmacokinetics and tissue distribution in rats;to enrich the research content of pharmacokinetics of baicalin magnesium salt,and to provides an experimental and theoretical basis for the rational design and clinical application of baicalin magnesium salt oral drug delivery system.Method:1.HPLC was used to establish the in vivo analysis method that concentrations of baicalin magnesium salt and baicalein were simultaneous determined in plasma and tissues of rats.2.12 healthy SD rats,they were randomly divided into fasted group and non-fasted group,6 rats in each group.According to the dose of 287.31mg/kg,Rats were given baicalin magnesium salt solution by gavage,blood samples were taken at the scheduled time points.The HPLC was used to determine plasma concentrations of baicalin magnesium salt and baicalein in rats at different time points.The DAS 3.0 pharmacokinetic software was used to calculate pharmacokinetic parameters.3.12 healthy SD rats,they were randomly divided into normal group and model group,6 rats in each group.In the model group,rats was injected intraperitoneally 50%CCl4olive oil solution to induce acute liver injury before intragastric administration 20 h,the control group was injected intraperitoneally the same volume of olive oil.According to the dose of287.31 mg/kg,Rats were given baicalin magnesium salt solution by gavage,blood samples were taken at the scheduled time points.The HPLC was used to determine plasma concentrations of baicalin magnesium salt and baicalein in rats at different time points.The DAS 3.0 pharmacokinetic software was used to calculate pharmacokinetic parameters.4.72 healthy SD rats,they were randomly divided into normal group and model group,6 rats in each group.In the model group,rats was injected intraperitoneally 50%CCl4olive oil solution to induce acute liver injury before intragastric administration 20 h,the control group was injected intraperitoneally the same volume of olive oil.According to the dose of287.31 mg/kg,Rats were given baicalin magnesium salt solution by gavage,the rats were anesthetized at the scheduled time point,the liver,lung,kidney,stomach,brain and small intestine were harvested.The HPLC was used to determine tissues concentrations of baicalin magnesium salt and baicalein in rats at different time points.The DAS 3.0 pharmacokinetic software was used to calculate main pharmacokinetic parameters in different tissues.Result:1.In paper,the established analysis method of HPLC to determinate baicalin magnesium salt and baicalein in plasma and tissues of rats,it was in accordance with the guiding principle of biological samples analysis methods validation.The method had good linearity,precision and specificity.The sample is stable under the experimental conditions and the endogenous substances did not interfere with determination.2.In fasted and non-fasted conditions,after rats were given baicalin magnesium salt（287.31 mg/kg）aqueous solution by gavage,baicalein was hardly detected in plasma.The concentration time curve of baicalin magnesium salt showed double peaks.Peak time(Tmax)of baicalin magnesium salt was 0.167 h in fasted group;Tmaxof baicalin magnesium salt was 8 h in non-fasted group.The main pharmacokinetic parameters peak concentration(Cmax)are（6.390±1.661）mg/L and（2.937±1.271）mg/L respectively;area under blood concentration time curve(AUC（0-t）)are（77.495±25.138）mg/L·h and（49.366±23.405）mg/L·h,respectively.In fasted conditions,the Cmaxwas 2.18 times that of the non-fasted group（P<0.01）,and the AUC（0-t）was 1.6 times that of the non-fasted group（P>0.05）.3.In normal and liver injury conditions,after rats were given baicalin magnesium salt（287.31 mg/kg）aqueous solution by gavage,baicalein was hardly detected in plasma.The concentration time curve of baicalin magnesium salt showed double peaks.Peak time(Tmax)of baicalin magnesium salt was 0.167 h in normal group;Tmaxof baicalin magnesium salt was 0.083 h in liver injury model group.The main pharmacokinetic parameters Cmaxare（6.890±3.798）mg/L and（3.983±2.770）mg/L respectively;AUC（0-t）are（96.567±34.475）mg/L·h and（48.82±12.915）mg/L·h respectively;apparent distribution solution（Vz/F）are（25.925±19.054）L/kg and（60.255±23.692）L/kg respectively.In liver injury conditions,the Cmaxwas 0.43 times that of the normal group（P>0.05）,the AUC（0-t）was 0.5 times that of the normal group（P<0.05）,the Vz/F was 2.3times that of the normal group（P<0.05）.4.In the normal group,the AUC（0-t）of baicalin magnesium salt from large to small was small intestine>stomach>kidney>lung>liver>brain;the AUC（0-t）of baicalein from large to small was small intestine>stomach>kidney>liver>lung.In the model group,the AUC（0-t）of baicalin magnesium salt from large to small was small intestine>stomach>kidney>liver>lung>brain;the AUC（0-t）of baicalein from large to small was small intestine>stomach>kidney>liver>lung.Compared with the normal group,the AUC（0-t）and Cmaxof baicalin magnesium salt were significantly increased in the liver,lung,kidney,stomach,brain,and small intestine of the model group,while the AUC（0-t）of liver was greater than the lung;the AUC（0-t）and Cmaxof baicalein were also significantly increased in the liver,lung,stomach and small intestine,while the AUC（0-t）and Cmaxof baicalein were slightly less than kidney of normal group.In the model group,the ratio of AUC（0-t）of baicalin magnesium salt to AUC（0-t）of baicalein in the lung,stomach,and small intestine was lower than that of the normal group,while the ratio of AUC（0-t）of baicalin magnesium salt to AUC（0-t）of baicalein in liver and kidney was higher than that of the normal group.Conclusion:1.In this experiment,established to determinate baicalin magnesium salt and baicalein in vivo analysis method that strong specificity and high accuracy,it can be used to determine the pharmacokinetics and tissue distribution of magnesium baicalin in SD rats.2.After the rats were given the same dose of baicalin magnesium salt by gavage,the plasma concentration-time curve of baicalin magnesium salt showed double peaks in fasted group and non-fasted group,and the main pharmacokinetic parameters AUC（0-t）and Cmax,were significantly different,suggesting that food can affect the pharmacokinetic behavior of baicalin magnesium salt in rats.3.After the rats were given the same dose of baicalin magnesium salt by gavage,the plasma concentration-time curve of baicalin magnesium salt showed double peaks in normal rats and liver injury model rats,and the main pharmacokinetic parameters AUC（0-t）,Cmax,and Vz/F were significantly different,suggesting that liver injury can affect the pharmacokinetics of baicalin magnesium salt in rats.4.After the rats were given the same dose of baicalin magnesium salt by gavage,The results of tissue distribution of baicalin magnesium salt suggested that there was biotransformation of baicalin magnesium salt and baicalein in liver,lung,kidney,stomach and small intestine in normal and model rats.Moreover,CCl4induced liver injury not only affected the tissue distribution of baicalin magnesium salt,but also affected the biotransformation of baicalin magnesium salt and baicalein in vivo. |
PDF Full Text Request