[Simultaneous determination of 11 neurotransmitters in brain microdialysis samples from rats by UPLC-MS/MS].

This study established a method for simultaneous determination of 11 neurotransmitters, such as acetylcholine, glutamic acid, glycine, and norepinephrine from rat brain microdialysis samples using UPLC-MS/MS. A total of 20 µL of rat brain dialysate was diluted with 60 µL of acetonitrile-water(4∶1) and centrifuged for 10 min at 10 000 r·min~(-1),and 5 µL was injected into UPLC-MS/MS system for assay. Chromatographic separation was performed on a Waters ACQUITY BEH amide column(2.1 mm×100 mm, 1.7 µm) with gradient elution using acetonitrile/0.2% formic acid-water as mobile phases with a flow rate of 0.35 mL·min~(-1) and column temperature of 35 ℃. The eluate was detected by multiple-reaction monitoring(MRM) scanning with an electrospray ionization source operating in the positive ionization mode with an analysis duration of 3.5 min. The relationship between the recovery rate of 11 neurotransmitters and the perfusion rate or the concentration of neurotransmitters was investigated. Furthermore, the effects of puerarin alone or combined with borneol on the content of 11 neurotransmitters in the striatum of rats were investigated. The results showed the calibration curves displayed good linear regression with coefficients all greater than 0.99 and the lower limit of quantification(LLOQ) less than 12.5 nmol·L~(-1) for each analyte. The within-run and between-run precision(RSD) of the 11 neurotransmitters at low, medium, and high levels was less than 9.3%, and the relative error of the accuracy ranged from-8.4% to 9.5%. The stability, recovery, and matrix effects were in line with the biological sample analysis requirements. As revealed by experimental results, the levels of most neurotransmitters in the brain striatum changed significantly after rats were treated with puerarin as compared with the conditions in the blank group. Except for dopamine and norepinephrine, the degree of changes of other neurotransmitters in the combination group(borneol and puerarin) was less than that of the puerarin group. The established UPLC-MS/MS method could be applied to the quantitative determination of 11 neurotransmitters in microdialysis samples, providing an efficient and useful tool to study neurotransmitter changes in animal models of health and diseases.

Pharmacokinetic comparison of five xanthones in rat plasma after oral administration of crude and processed Garcinia hanburyi extracts.

Gamboge, a dried resin secreted by Garcinia hanburyi Hook. f. (Guttiferae), possesses remarkable anticancer activity. However, due to toxicity, it must be processed before use in clinics. Xanthones are the main bioactive ingredients in gamboge. In order to elucidate the influence of processing technology on pharmacological properties of gamboge, an efficient, sensitive, and selective ultra-performance liquid chromatography coupled with triple quadruple mass spectrometry (UPLC-MS/MS) method of five critical xanthones, including ß-morellic acid (ß-MA), isogambogenic acid (IGNA), gambogenic acid (GNA), R-gambogic acid (GA), and S-GA in rat plasma was established for a comparative pharmacokinetics study of these xanthones after oral administration of crude and processed G. hanburyi extracts. The chromatographic separation of these five xanthones along with an internal standard (I.S.) was carried out on a Waters Acquity UPLC BEH C8 column with a gradient elution method using acetonitrile/0.1% formic acid-water as mobile phases. The eluate was detected by multiple-reaction monitoring (MRM) scanning with an electrospray ionization source operating in the positive ionization mode. Sample preparation involved a liquid-liquid extraction of the five analytes with ethyl acetate. Deoxyschizandrin was employed as an internal standard. This assay method was validated for selectivity, linearity, intra-day and inter-day precision, accuracy, recovery, matrix effect, and stability. The results revealed that the calibration curves displayed good linear regression (r > 0.995), and the lower limit of quantification (LLOQ) was <5.52 ng/mL for each analyte. The intra-day and inter-day precision (RSD) of the five xanthones at low, medium, and high levels was <10.58%, and the bias of the accuracy ranged from -8.54 to 10.2%. All other parameters fulfilled the FDA criteria for bioanalytical validation. In addition, the assay was successfully applied to the determination and pharmacokinetic study of these five xanthones after oral administration of crude and processed gamboge. Furthermore, Cmax of GNA and AUC0-t of IGNA were increased significantly (P < 0.05) after processing, while AUC0-t of ß-MA, R-GA, and S-GA decreased remarkably (P < 0.05), which suggested that processing exerted different effects on the absorption of xanthones. The results might be valuable for the clinical reasonable application and understanding the processing mechanism of gamboge.

[Effect of Ginkgo biloba Tablet on the Expression of Scavenger Receptor A of the Aortic Wall in Atherosclerotic Rats].

OBJECTIVE: To observe the expression of Ginkgo biloba Tablet (GbT) on scavenger receptor A (SRA) of the aortic wall and changes of serum inflammatory factors in atherosclerotic rats, and to explore its new mechanism for fighting against atherosclerosis (AS). METHODS: Totally 45 male Wistar rats were randomly divided into the control group, the model group, the GbT group, 15 rats in each group. Levels of blood glucose, blood lipids, blood calcium, serum C-reactive protein (CRP), soluble intercellular adhesion molecule-1 (slCAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured in all rats. The expression of SRA in the aortic wall of atherosclerotic rats was observed by immunohistochemical assay. The correlation between the expression of SRA and levels of in-flammatory factors was also observed. RESULTS: Compared with the control group, blood glucose and blood calcium obviously increased (P < 0.05); levels of TG, TC, and LDL-C were significantly elevated (P < 0.01); neointimal areas were significantly thickened, increased intima percentage was significantly enlarged, narrowed lumen index was significantly reduced; levels of CRP, sICAM-1, and sVCAM-1 were significantly elevated in the model group (all P < 0.01). Compared with the model group, blood glucose and blood calcium obviously decreased (P < 0.05); levels of TG, TC, and LDL-C significantly decreased (P < 0.01) in the GbT group. Aortic lumens were obviously narrower in the model group than in the GbT group (P < 0.05). SRA expressed at the aortic wall. The aforesaid 3 indices were significantly improved in the GbT group than in the model group (P < 0.01). Serum levels of CRP, sICAM-1, and sVCAM-1 were significantly decreased in the GbT group than in the model group (P < 0.01). Serum levels of CRP, sICAM-1, and sVCAM-1 were positively correlated with the percentage of SRA positive expression area (r = 0.701, 0.604, 0.581, all P < 0.01). CONCLUSIONS: Serum levels of inflammatory factors in atherosclerotic rats were elevated, and the expression of SRA in the aortic wall was enhanced. The expression of SRA was closely correlated with serum levels of inflammatory factors. GbT could decrease serum levels of inflammatory factors and inhibit the expression of SRA.

[Attenuation mechanism of gamboges during processing based on inflammatory toxicity and AQP3, AQP4 protein and mRNA expressions in rat gastric and duodenal tissues].

To expand the clinical application of gamboges, it is necessary to study crude gamboges' toxicity after oral administration and attenuation mechanism during processing. In this study, crude gamboges' toxicity was judged by multiple assays, including inflammatory mediums [such as nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and interleukin 6 (IL-6)] released by macrophage RAW264.7, and pathological manifestations of rat stomach and duodenal tissues after oral administration with crude and processed gamboges. The attenuation mechanism during processing was studied by detecting AQP3, AQP4 protein and mRNA expression in rat gastric and duodenal tissues using immunohistochemical assay and real-time fluorescent quantitative PCR technique. According to the results, crude gamboges group showed promotion in release of NO, TNF-α and IL-6 by macrophage RAW264.7 in a dose-dependent manner; Compared with crude gamboges group, processed gamboges group showed reduction in release of NO and IL-6, with increase in TNF-α. Crude gamboges could cause rat diarrhea, white blood cells increase, lymphocytes decrease, hyperemia and edema in rat gastric mucosa, duodenal mucosal necrosis and inflammatory cells infiltration. All of these results proved that gamboges had the inflammatory toxicity in gastric and duodenal tissues after oral administration in a dose-dependent manner, which however reduced after processing. In addition to the inflammatory toxicity, the mRNA and protein expressions of aquaporin 3 (AQP3), aquaporin 4 (AQP4) in gastric and duodenal tissues of high-dose crude gamboges group were increased significantly (P<0.05), while the protein and mRNA expressions of AQP3, AQP4 were weakened in processed gamboges group. The results showed that AQP3, AQP4 protein and mRNA expressions were positively correlated with the inflammatory toxicity. In conclusion, down-regulation of AQP3, AQP4 protein and mRNA expressions may be one of attenuation mechanisms in processing gamboges.

[Study on tissue distribution of psoraleae fructus decoction in rats].

Advanced technologies are used to clarify the meridian tropism theory of traditional Chinese medicine is an important part of theoretical studies of traditional Chinese medicine. In this article, modern pharmacokinetic method was used to investigate tissue distribution characteristics of psoralen and isopsoralen of Psoraleae Fructus decoction in rats, in order to provide research ideas and experimental basis for the meridian tropism theory. In this study, various tissue samples such as heart, liver, spleen, lung, kidney, brain and spermary were collected at different times after oral administration with FP decoction, in order to determine concentration of psoralen and isopsoralen by HPLC. Pharmacokinetic parameters were calculated by DAS 2.0 software. The study results showed that HPLC indexes of psoralen and isopsoralen in various tissues of rats met the determination requirements of biological samples. Both components were distributed in all of the tissues, with AUC(0-t) order of liver > lung approximately kidney > heart > brain approximately spleen > spermary. There was significant difference between liver, kidney, lung and other tissues (P < 0.05). MRT(0-t) of both psoralen and isopsoralen were about 10 h. Therefore, psoralen and isopsoralen showed stronger targeting selection in liver, kidney and lung.