Sensitive Analysis and Pharmacokinetic Study of Berberrubine Using LC-MS/MS

Objective To develop a sensitive and reproducible liquid chromatography-tandem mass spectrometry（LC-MS/MS） method to evaluate the pharmacokinetic behavior of berberrubine（BRB） and its glucuronide（BRBG） in rats. Methods BRB, BRBG and tetrahydroberberine（THB, internal standard） were isolated by liquid-liquid extraction in rat biological samples. Chromatographic separation was achieved on an Agilent Zorbax Eclipse Plus C_（18）（2.1 mm × 50 mm, 3.5-Micron） with a gradient mobile phases primarily containing acetonitrile, water with 0.1% formic acid and 5 mm ammonium acetate. The analytes were monitored by MS/MS in positive electrospray ionization mode. Herein, the feasibility of new developed method was validated with respect to specificity, linearity, precision, accuracy, stability, extraction efficiency and matrix effect. The appropriate method was used for the pharmacokinetic study in rats.Results The new developed method could be applied to the pharmacokinetic study of BRB in rats. BRB and BRBG showed good linearity over the ranges of 2-1000 ng/mL and 5-2000 ng/mL, respectively, and precision was no more than 15%. The accuracy, specificity and stability could be acceptable. Conclusion The new method is sensitive and reproducible. In pharmacokinetic study, BRB showed nonlinear elimination property. Meanwhile, BRB was rapidly absorbed and widely distributed in various tissues with the highest exposure of BRB in kidney and liver. The absolute bioavailability of BRB was determined to be 8.2% and at the dose of 40 mg/kg, a total of 44% BRB was excreted in urine and feces.

Protective Effect of Salvianolic Acid A on Brain Endothelial Cells after Treatment with Deprivation and Reperfusion of Oxygen-glucose

Objective Salvianolic acid A（SAA） has a significant protective effect on ischemia/reperfusion injury of brain. However, it is not clear for SAA to exert its cerebral protection by targeting at the microvascular endothelial cells of blood brain barrier（BBB）. Our previous study demonstrated that SAA could hardly pass through the BBB. This present study was therefore designed to investigate the protective effect of SAA on brain microvascular endothelial cells（BMECs） induced by deprivation and reperfusion with oxygen-glucose. Methods Rat BMECs were treated with oxygen glucose deprivation（OGD）, followed by reperfusion（OGD/R）. Cell viability was assessed by MTT and the content of reactive oxygen species（ROS） in cells after OGD/R in the absence or presence of SAA. GC-MS based metabolomic platform was applied to evaluate the regulation of SAA on the cellular metabolic perturbation induced by OGD/R. Results OGD/R significantly increased the production of intracellular reactive oxygen species（ROS）, and decreased the activity of cells. SAA significantly reduced ROS and improve the cell viability. Metabolomic study revealed distinct perturbation of metabolic pathways of energy metabolism in the BMEC induced by OGD/R, while SAA significantly regulated the perturbed metabolism involved in energy metabolism pathways, especially for intermediates in TCA cycle. Conclusion SAA shows protective effects on BMECs involved in central nervous system.

Salidroside shows a particular pharmacokinetic property in model rats of myocardial ischemia

Objective：Salidroside showed potential pharmacological effect on plateau hypoxia and cardiovascular disease like myocardial ischemia.However,pharmacokinetic differences have not been assessed between the pathological model and the normal animals.This study focused on evaluating the pharmacokinetic properties of salidroside in animals with myocardial ischemia.Methods：A reproducible and sensitive method was established and optimized based on liquid chromatography tandem mass spectrometry（LC–MS/MS）to determine salidroside in rats plasma.The data showed thesalidroside proportionally increased along with dose elevation after singly intragastric administration of salidroside at a dose of 20,50,and 100 mg/kg.Results：Compared to the single dose,the Cmax,andsalidroside markedly decreased while CL/F and V/F increased after multiple dosing.However,theischemic model rats were 0.35 and 0.39 fold lower than those in normal rats after a single dose at 50 mg/kg,with an increased CL/F and V/F.Surprisingly,after a consecutive administration of salidroside for 7 d,the mean Cmax,2.89 and 2.61 fold higher than a single dose in model rats,and even 2.28 and4.03 fold higher than the normal controls after multiple doses.All the above fold values were statistically different（P〈0.01）.Conclusion：The particular PK properties of salidroside in ischemic model rats were presented in our study for the first time,suggesting that myocardial ischemia greatly affected pharmacokinetics exposure of the orally administrated salidroside after a single or multiple doses.