[ABSTRACT]AIM:Tostudytheprotectiveeffectofbrain-derivedneurotrophicfactor(BDNF)onvascularendo-thelial cells with H 2 O2-induced oxidative injury .METHODS: Human umbilical vein endothelial cells ( HUVECs ) were cultured in vitro, and the oxidation injury model of HUVECs was established by treatment with H 2 O2 .The oxidatively in-jured HUVECs were cultured with different concentrations (1, 10 and 100μg/L) of BDNF.At the same time, the control group (no injury), PBS treatment after H2O2 injury group and TrkB inhibitor group (with 100 μg/L BDNF and 1∶1 000 TrkB inhibitor) were also set up.The viability of the HUVECs was detected by MTT assay .The levels of LDH, MDA, SOD and GSH were measured .The releases of NO , ET-1 and ICAM-1 were analyzed by ELISA .The changes of ROS pro-duction and cell apoptosis were evaluated by flow cytometry .The protein levels of TrkB , p-TrkB, cleaved caspase-3, Bcl-2 and Bax were determined by Western blot .RESULTS:Compared with uninjured control group , in H2 O2 oxidative injury plus PBS treatment group , the viability of the cells was decreased significantly , the LDH and MDA levels were increased significantly and the activities of SOD and GSH were decreased significantly .The NO secretion was decreased , and the ET-1 and ICAM-1 concentrations were increased significantly .The ROS content and apoptotic rate were increased significantly . The protein levels of cleaved caspase-3 and Bax were increased but Bcl-2 protein expression was decreased significantly . Compared with PBS treatment group , in H2 O2-injured HUVECs treated with different concentrations of BDNF , the cell via-bility was gradually increased , the LDH and MDA levels were decreased and the activities of SOD and GSH were increased gradually .The secretion of NO was increased but ET-1 and ICAM-1 were decreased gradually .The ROS content and apop-totic rate were decreased significantly .The TrkB and p-TrkB levels were significantly increased significantly , the protein expression of cleaved-caspase 3 and Bax was decreased gradually and the Bcl-2 protein expression increased gradually .The role of BDNF was inhibited by TrkB inhibitor .CONCLUSION:BDNF protects HUVECs from oxidative injury by binding with TrkB to activate the BDNF-TrkB signaling pathways .

Objective: To investigate the effect of tanshinone IIA (TSN) on left ventricular hypertrophy (LVH) and cardiomyocyte apoptosis in spontaneous hypertensive rats (SHRs). Methods: A total of 60 SHRs at 8 weeks of age were randomly divided into 3 group: Blank control group, the rats were sacriifced at 8 weeks, TSN group, the rats were treated with TSN at 1 ml/(kg?d) for 18 weeks and Solvent control group, the rats were treated with the solvent at 1 ml/(kg?d) for 18 weeks. n=20 in each group and 15 rats were used for the experiments. The systolic blood pressure (SBP) and left ventricular mass index (LVMI) were examined, cardiomyocyte’s diameter and surface area were measured by HE staining, the apoptosis rate was evaluated by TUNEL method and the apoptosis related protein expression s of Bcl-2, Bax and p53 were determined by Western blot analysis. Results: ①Compared with Solvent control group, TSN group had decreased LVMI (3.23 ± 0.24) mg/g vs (4.58 ± 0.68) mg/g,cardiomyocyte’s diameter (16.13 ± 1.77) μm vs (27.15 ± 3.52) μm and surface area (230.23 ± 69.37) μm2 vs (490.12 ± 118.96) μm2and decreased apoptosis rate (7.45 ± 1.78) % vs (10.61 ± 2.77) %, allP<0.01.②With NAPDH reference correction, compared with Solvent control group, TSN group presented increased protein expression of Bcl-2 (0.97 ± 0.31) vs (0.40 ± 0.11) and decreased Bax (0.37 ± 0.15) vs (1.81 ± 0.44), decreased p53 (0.83 ± 0.18) vs (2.72 ± 0.28), allP<0.05 or P<0.01. The above indexes were similar between TSN group and Blank control group,P>0.05. Conclusion: TSN could inhibit the development of LVH and decrease the cardiomyocyte apoptosis, which might be via up-regulating the protein expressions of Bcl-2 and down-regulating Bax and p53 in SHRs.

A selective precolumn derivatization liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the determination of glucosamine in human plasma and urine has been developed and validated.Glucosamine was derivatized by o-phthalaldehyde/3-mercaptopropionic acid.Chromatographic separation was performed on a Phenomenex ODS column (150 mm × 4.6mm,5μm) using linear gradient elution by a mobile phase consisting of methanol (A),and an aqueous solution containing 0.2％ ammonium acetate and 0.1％ formic acid (B) at a flow rate of 1 mL/min.Tolterodine tartrate was used as the internal standard (IS).With protein precipitation by acetonitrile and then the simple one-step derivatization,a sensitive bio-assay was achieved with the lower limit of quantitation (LLOQ) as low as 12 ng/mL for plasma.The standard addition calibration curves suitable for clinical sample analysis showed good linearity over the range of 0.012-8.27 μg/mL in plasma and 1.80-84.1 μg/mL in urine.The fully validated method has been successfully applied to a pharmacokinetic study of compound glucosamine sulfate dispersible tablets in health Chinese volunteers receiving single oral doses at 500,1000 and 1500 mg of glucosamine sulfate,as well as multiple oral doses of 500 mg t.i.d.for 7 consecutive days.

Objective To investigate the effects of brain-derived neurotrophic factor (BDNF) pretreatment on H9c2 myocardial hypoxia/reoxygenation (H/R) injury, and explore its mechanism. Methods The H9c2 myocardial cells were cul?tured in vitro and (95%O2+5%CO2) oxygen cultured 12 h after (95%N2+5%CO2) hypoxia cultured 4 h to establish the H/R model. The cells were divided into normal control group, H/R group, different concentrations (1, 10, 100μg/L) BDNF pre?treatment in H/R groups and TrkB-inhibitor group (with 100μg/L BDNF and 1∶1 000 TrkB inhibitor pre-treatment in H/R group). The cell survival rate was measured by MTT method in different groups. The lactate dehydrogenase (LDH), creatine kinase (CK), malondialdehyde (MDA) and superoxide dismutase (SOD) content and activity were detected after H/R injury. The apoptotic rate of H9c2 myocardial cells were detected by flow cytometry, and the expressions of TrkB, Bcl-2 and Bax protein were detected by Western blot assay. Results Compared with the normal control group, the survival rate of H9c2 myocardial cells was decreased significantly in H/R model group (P < 0.05), LDH, CK and MDA contents were increased and SOD activity was decreased (P<0.05). The cell apoptosis rate was increased significantly (P<0.05). The anti-apoptosis Bcl-2 protein expression was decreased, pro-apoptosis Bax protein expression was increased in H/R model group (P<0.05). Compared with the H/R model group, the cell survival rates of H9c2 myocardial cells were increased after pre-treatment with different concentrations of BDNF (P<0.05);LDH, CK and MDA contents were decreased and SOD activity were in?creased respectively (P < 0.05). The cell apoptotic rates were decreased (P < 0.05). The expressions of TrkB receptor and Bcl-2 protein gradually increased, while the expression of Bax protein was gradually decreased (P<0.05). The role of BDNF was inhibited by TrkB inhibitor. Conclusion BDNF pre-treatment can promote the cell survival rate of H9c2 myocardial cells after H/R injury, which plays a protective role by inhibiting the cell apoptotic rate and maintaining antioxidant capacity, and associates with BDNF-TrkB signaling pathways.

An LC-TOF /MS and LC-MS /MS method was established for the identification the related substances in ambrisentan.HPLC separation was carried out on an XBridge C18 column(4.6 mm ×150 mm,3.5 μm)with linear gradient elution using a mobile phase consists of acetonitrile,water and 0.15% formic acid.The structures of the related substances were identified by electrospray positive ESI high resolution TOF /MS and MS /MS spec-tra,and verified further through reference substances.Ambrisentan and its related substances can be separated under the established HPLC conditions.Ten related substances were detected and identified.The established method is useful for the identification of related substances in ambrisentan.The results obtained are valuable for its manufacturing process optimization and quality control.

Simple and sensitive methods were developed for the determination of indapamide, perindopril and its active metabolite perindoprilat in human plasma or whole blood by hyphenated ultra-performance li-quid chromatography-mass spectrometry (UPLC-MS/MS). Indapamide-d3, perindopril-d4 and perindo-prilat-d4 were used as the internal standards. The separation was performed on a Thermo BDS Hypersil C18column (4.6 mm × 100 mm, 2.4 μm) for indapamide and perindopril simultaneously following a protein precipitation pretreatment of the biosamples. The separation of perindoprilat was achieved in-dependently on a phenomenex PFP column (4.6 mm × 150 mm, 5 μm). All the analytes were quantitated with positive electrospray ionization and multiple reactions monitoring mode. The assay exhibited a linear range of 1–250 ng/mL for indapamide, 0.4–100 ng/mL for perindopril and 0.2–20 ng/mL for peri-ndoprilat. The methods were fully validated to meet the requirements for bioassay in accuracy, precision, recovery, reproducibility, stabilities and matrix effects, and successfully applied to the pharmacokinetic study of perindopril tert-butylamine/indapamide compound tablets in Chinese healthy volunteers and the comparative pharmacokinetic study between plasma and whole blood.

To identify the related substances in pioglitazone hydrochloride by hyphenated LC-MS techniques,an Ultimate XB-C18 (250 mm × 4.6 mm,5 μm) column was used for separation of the related substances with methanol and 0.1％ ammonium acetate buffer as the mobile phases in gradient elution.Electrospray positive ionization high resolution TOF/MS was used for the determination of the accurate mass and elemental composition of parent [M + H] + ions of the related substances,and triple quadrupole tandem mass spectrometry was employed for the product mass spectra determination.Eleven major related substances were detected and identified to be one synthesis intermediate,six by-products and four degradation products,by using LC-MS determination,spectra elucidation,and further synthetic process and stress degradation mechanisms analysis.The results are useful for pioglitazone hydrochloride manufacturing processes optimization and quality control.

Objective: To establish a method for determining the molecular weight and molecular weight distribution of Poly(Lactide-co-Glycolide Acid) (PLGA) using Size Exclusion Chromatography-Refractive Index-Multiangle Laser Light Scattering (SEC-RI-MALLS) and Size Exclusion Chromatography-Refractive Index (SEC-RID), and to compare the results obtained from these two methods.
Methods: For SEC-RI-MALLS, tetrahydrofuran was used as the mobile phase, Shodex GPC KF-803L was employed as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, and an injection volume of 100 μL. For SEC-RID, tetrahydrofuran was also used as the mobile phase, Agilent PLgel 5 μm MIXD-D was used as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, differential detector temperature at 35 ℃, and an injection volume of 20 μL. The molecular weight and molecular weight distribution were calculated using Agilent’s GPC software. The newly established methods were validated methodologically, and the molecular weight and molecular weight distribution of 13 batches of samples were determined.
Results: The precision, accuracy, stability, and repeatability tests for SEC-RI-MALLS showed RSD values of 1.35%, 1.58%, 1.53%, and 1.26%, respectively. The SEC-RID method exhibited good linearity (r=0.999 9), with RSD values for precision, accuracy, stability, and repeatability tests (n=6) of 2.05%, 1.62%, 1.30%, and 2.97%, respectively. The results obtained from SEC-RI-MALLS were lower than those from SEC-RID, and the molecular weight distribution coefficient was smaller, but the results from the paired T-test performed with the value measured by SEC-RID method and the value measured by SEC-RI-MALLS method multiplied a conversion coefficient of 1.5 showed no significant difference between the two methods.
Conclusion: Both methods are stable and reliable, and can be used for the determination of PLGA molecular weight and molecular weight distribution based on the specific situations.

At present , methamphetamine has become a major hidden danger in global public health safety. In order to judge methamphetamine addicts and methamphetamine abstainers more scientifically and reliably, this study analyzed the endogenous metabolites in plasma, serum and urine of methamphetamine addicts, methamphetamine abstainers and healthy volunteers by highly sensitive high-throughput liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) analytical instrument. The obtained metabolomic data were processed by univariate analysis (t-test) and multivariate analysis (PLS-DA and OPLS-DA) and eligible potential biomarkers were then screened.The identified biomarkers set enrichment analysis to find the connection between metabolites and metabolic pathways.Multivariate statistical results showed that methamphetamine acute group, recovery group and healthy group were clearly separated.3, 18 and 6 regulated metabolites were identified in serum, plasma and urine, respectively, suggesting that lipid metabolism was abnormal in methamphetamine acute group, and that fatty acid metabolism, sulfate/sulfite metabolism and sex hormone metabolism were abnormal in methamphetamine recovery group.The selected potential biomarkers in this study provide the possibility for scientific judgment of the clinical stage of methamphetamine detoxification.

The waste water-based epidemiology is an important technique to fight against drug abuse by analyzing the concentration of illicit drugs in urban sewage, which can monitor the abuse of drugs.An SPE-UPLC-MS/MS method was developed for the analysis of 12 common drugs and their metabolites involving amphetamine and morphine.It was shown that the best result was achieved when hydrochloric acid/ acetonitrile (5∶95) was added to acidify the sample during the concentration process, guaranteeing the anti-across contamination of the analysis of organic nitrogen basic trace components, and improve the stability, specificity, and accuracy of the method.The optimized method meets the analytical requirements of complex sewage samples, and has been successfully applied to the assessment of urban drug abuse through sewage analysis.