[Assay of amino acids in leaves of Eucommia ulmoides under arbor forest mode and leaf-oriented cultivation mode by pre-column derivatization HPLC].

This study aims to develop the pre-column derivatization high performance liquid chromatography(HPLC) method for the determination of 16 kinds of amino acids in Eucommia ulmoides leaves, and compare the content of amino acids in the leaves harvested at different time and under leaf-oriented cultivation mode(LCM) and arbor forest mode(AFM). The HPLC conditions are as below: phenyl isothiocyanate(PITC) as pre-column derivatization agent, Agilent ZORBAX C_(18 )column(4.6 mm×250 mm, 5 µm), mobile phase A of acetonitrile-water(80∶20), mobile phase B of 0.1 mol·L~(-1) sodium acetate solution-acetonitrile(94∶6), gradient elution, flow rate of 1.0 mL·min~(-1), injection volume of 5 µL, column temperature of 40 ℃, and detection wavelength of 254 nm. The HPLC profile indicated well separation of 16 kinds of amino acids and the amino acid content in E. ulmoides leaves was up to 16.26%. In addition, the amino acid content in leaves of E. ulmoides under LCM was higher than under AFM. The amino acid content varied with the harvesting time. Through orthogonal partial least squares discriminant analysis, the amino acids of E. ulmoides under LCM and AFM were compared, which can distinguish the leaves under LCM from those under AFM. Principal component analysis was applied to comprehensively score the amino acids of E. ulmoides leaves. The results showed that the score of leaves under LCM was higher than that under AFM. Nutritional evaluation results indicated that the proteins in E. ulmoides leaves belonged to high-quality vegetable proteins. The established method for the determination of amino acid content is reliable. With the amino acid content as index, the leaf quality of E. ulmoides under LCM is better than that under AFM. This study lays a theoretical basis for the promotion of LCM for E. ulmoides and the development of medicinal and edible products from E. ulmoides leaves.

[Spleen deficiency and phlegm dampness syndrome model in rats treated by Citri Reticulatae Pericarpium based on metabolomics].

The present study analyzed the effect of Citri Reticulatae Pericarpium on endogenous metabolites in spleen deficiency and phlegm dampness syndrome by metabolomics, and explored the underlying mechanism of Citri Reticulatae Pericarpium in the treatment of spleen deficiency and phlegm dampness syndrome.The model of spleen deficiency and phlegm dampness syndrome was induced in rats by the multi-factor modeling method.The intervention effects of Citri Reticulatae Pericarpium on rats with spleen deficiency and phlegm dampness syndrome were preliminarily evaluated by observing the pathological changes of rat liver tissues and measuring the plasma content of pathological and biochemical indexes such as triglyceride(TG), total cholesterol(TC), low-density lipoprotein cholesterol(LDL-C), and high-density lipoprotein cholesterol(HDL-C).Immunohistochemistry was used to detect the expression of AQP2 in the kidney, AQP3 in the colon, and AQP5 in the submandibular gland, and the effect of Citri Reticulatae Pericarpium on aquaporin expression in rats with spleen deficiency and phlegm dampness syndrome was evaluated.Furthermore, UHPLC-ESI-MS/MS was used to analyze the metabolic profiles of rat plasma samples.Multiple methods, such as principal component analysis(PCA) and orthogonal partial least squares discriminant analysis(OPLS-DA) were used for pattern recognition.Differential metabolites were screened out by t-test and variable importance in projection(VIP), followed by pathway analysis based on MetaboAnalyst 5.0.As revealed by experimental results, Citri Reticulatae Pericarpium could improve the pathological changes of liver tissues, increase the levels of HDL-C in the plasma, reduce the levels of TC, TG, and LDL-C, and enhance the expression of AQP2 in the kidney, AQP3 in the colon, and AQP5 in the submandibular gland of rats with spleen deficiency and phlegm dampness syndrome.In addition, 87 differential metabolites of spleen deficiency and phlegm dampness syndrome were screened out by UHPLC-ESI-MS/MS(the levels of 39 metabolites increased significantly and the levels of 48 metabolites decreased significantly), with the representatives of glycine, L-isoleucine, N-acetyl-L-tyrosine, xanthine, hypoxanthine, and trigonelline.The differential metabolites were mainly enriched in the pathways of steroid hormone biosynthesis, linoleic acid metabolism, and purine metabolism.This study distinguished and revealed the characteristic metabolic pattern of spleen deficiency and phlegm dampness syndrome by metabolomics.The preliminary construction of the OPLS-DA model provides an objective basis for the differentiation of spleen deficiency and phlegm dampness syndrome in traditional Chinese medi-cine(TCM), as well as ideas and methods for exploring the biological basis of TCM syndrome from the molecular level and the overall level.

Switching Between LC-ESI-MS/MS and EMIT Methods for Routine TDM of Valproic Acid in Pediatric Patients With Epilepsy: What Clinicians and Researchers Need to Know.

Background: Valproic acid (VPA) is a widely used antiseizure medication and its dosing needs to be tailored individually through therapeutic drug monitoring (TDM) to avoid or prevent toxicity. Currently, immune-enzymatic assays such as Enzyme Multiplied Immunoassay Technique (EMIT), and Liquid Chromatography (LC)-based techniques, particularly coupled to Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS), resulting a potential lack of concordance between laboratories. Methods: In this study, plasma VPA concentrations were determined for 711 pediatric patients with epilepsy by a routine EMIT assay and by a validated in-house LC-ESI-MS/MS method on the same group of samples, aimed to address the aforementioned concern. Consistency between two assays was evaluated using linear regression and Bland-Altman analysis. Results: The calibration curve was linear in the range of 5.00-300 µg/ml for LC-ESI-MS/MS method and 1.00-150 µg/ml for EMIT assay, respectively. The two methods were proven to be accurate with quality control samples. As a result, a significant correlation between two methods was obtained with a regression equation described as [ EMIT ] = 1.214 × [ LC - ESI - MS / MS ] + 3.054 (r 2 = 0.9281). Bland-Altman plot showed a mean bias of 14.5 µg/ml (95% confidence interval (CI) (-0.2, 29.2) and a mean increase of 27.8% (95% CI (3.3, 52.4) measured by EMIT assay more than that measured by LC-ESI-MS/MS method. Conclusion: In conclusion, two methods were closely correlated, but EMIT assay overestimate VPA levels in human plasma compared with LC-ESI-MS/MS method. Due to the observed significant discordance between the tested methods, switching from immunoassays to LC-based techniques for TDM of VPA deserves close attention and therapeutic range of 35.0-75.0 µg/ml may be feasible. However, further studies are needed to evaluate the eligibility of this alternative range in the clinical practice. Clinicians should be informed when switching the VPA quantitation methods during the clinical practice.

[Gly14]-Humanin Ameliorates High Glucose-Induced Apoptosis by Inhibiting the Expression of MicroRNA-155 in Endothelial Microparticles.

BACKGROUND: Humanin, a newly emerging endogenously expressed cytoprotective peptide, has been shown to have anti-apoptotic properties effects by protecting neuronal cells injury. Endothelial microparticles (EMPs) are considered as vital mediators in intercellular communication. EMPs may regulate various physiological and pathological processes by transferring mRNAs and microRNAs (miRNAs) to recipient cells. METHODS: EMPs were isolated from human umbilical vein endothelial cells (HUVECs) by ultracentrifugation. EMPs were characterized by transmission electron microscopy and nanoparticle tracking analyses. Observation of EMPs uptake into HUVECs and the number of EMPs were realized by confocal microscopy. The expression of miR-155 was examined using real-time PCR. Cell apoptosis was examined by flow cytometry assay. RESULTS: We found that high glucose (HG) increased the number of EMPs and upregulated the expression of miR-155 contained within EMPs, which was mitigated by HNG pretreatment. miR-155 overexpression in EMPs reversed the effects of HNG pretreatment and increased apoptosis of target cells. Effects of HNG pretreatment on HG-treated endothelial cells (ECs) were mitigated after miR-155 mimic transfection into HUVECs while were augmented after miR-155 inhibitor transfection into HUVECs. CONCLUSION: HNG inhibited HG-induced apoptosis of ECs and the effect of HNG may be mediated by inhibiting the transfer of EMPs miR-155 from HG-induced HUVECs to normal cells. This study provides a new direction for biological products related to humanin to treat vascular complications associated with all forms of diabetes mellitus.