Asymmetric oxidation synthesis of esomeprazole sodium:research advances / 国际药学研究杂志

Esomeprazole sodium is a widely used proton pump inhibitor which is mainly applied to the treatment of gastric ul-cer,duodenal ulcer,digestive esophagitis and gastritis. By reviewing the literature over the past decade on the asymmetric oxidation of esomeprazole sodium ,the paper summarizes the synthetic process and focuses on the comparison of the critical steps. To choose suit-able chiral catalyst to reduce the cost of synthesis of esomeprazole sodium,this paper compares beyond the yield,enantioselectivity and other aspects. The conclusion is that the catalysts used in the most of oxidation systems are with a large load and high cost ,and compared with the classical Kagan-Modena system,the Ti-salan catalyst has advantages in the synthesis of esomeprazole sodium,and can be widely used.

Reversal Effect of Dihydromyricetin on Drug Resistance of K562/A02 Cell Line to Adriamycin / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the reversal effect of dihydromyricetin(DMY) on drug resistance of K562/A02 cells to adriamycin and explore its possible mechanism.</p><p><b>METHODS</b>K562 and K562/A02 cells were treated with DMY (5, 10, 20, 40, 60, 80 and 100 mg/L) and ADM (100-0.05 mg/L) for 48 h. The viability of K562 cells and K562/A02 cells was tested and the reversal effect of DMY on drug resistance of K562/A02 cells to adriamycin was analyzed by MTT. The relative concentration of ADM in cells was measured by flow cytometry. Protein expressions of drug resistance related genes including P-glycoprotein (P-gp), multidrug resistance associated protein 1 (MRP1), glutathione transferase π (GSTπ) and BCL-2 were measured by Western Blot.</p><p><b>RESULTS</b>The proliferation of K562 and K562/A02 cells was significantly decreased by DMY in dose-dependent manner as compared with control group (r1=0.37, r2=0.38). The ICof ADM on K562 and K562/A02 cells were 71.23±6.51 and 72.88±5.49 mg/L respectively. DMY (5, 10 and 20 mg/L) was low cytotoxicity. DMY (5, 10 and 20 mg/L) enhanced the sensitivity of K562/A02 cells to ADM in dose-dependent manner (r1=-0.62, r2=-0.71) and the reversal multiples was from 1.38 to 28.591. The relative concentrations of ADM in K562/A02 of DMY (5, 10 and 20 mg/L) group cells were significantly increased in dose-dependent manner compared with the control group (r=0.34). Compared with the control group, the expressions of drug resistance related protein P-gp, MRP1, GSTπ and BCL-2 were significantly decreased in dose-dependent manner in DMY (5, 10 and 20 mg/L) group (r1=-0.41, r2=-0.37, r3=-0.58, r=-0.46). Compared with the ADM group, the protein expressions of drug resistance related genes P-gp, MRP1, GSTπ and BCL-2 in DMY (5, 10 and 20 mg/L)+ADM group were significantly decreased in dose-dependent manner (r1=-0.55, r2=-0.41, r3 =-0.38, r4=-0.44).</p><p><b>CONCLUSION</b>DMY enhances the sensitivity of K562/A02 cells to ADM, its mechanism may be related with decrease of P-gp, MRP1, GSTπ and BCL-2 expressions.</p>

Gly14-humanin protects against Aβ₃₁₋₃₅-induced impairment of spatial learning and memory in rats / 生理学报

Amyloid β protein (Aβ) is closely involved in the pathogenesis of Alzheimer's disease (AD), and one of the main strategies for AD treatment is antagonizing the neurotoxicity of Aβ or even clearing the Aβ deposited in the brain. The present study was aimed to observe the effects of intrahippocampal injection of Aβ₃₁₋₃₅ on the spatial learning and memory of rats by using Morris water maze technique, and explore the neuroprotective effects and possible mechanism of [Gly14]-humanin (HNG) against Aβ-induced deficits in learning behavior. The results showed that bilateral intrahippocampal injection of 2.0 nmol Aβ₃₁₋₃₅ significantly increased the mean traveled distance of rats in searching for the hidden underwater platform and decreased the distance percentage in the target quadrant in probe test after withdrawal of platform, whereas pretreatment with HNG (0.2 nmol and 2.0 nmol) suppressed Aβ₃₁₋₃₅-induced increase in the traveled distance and decrease in swimming distance percentage. Application of Genistein (40 nmol), a specific tyrosine kinase inhibitor, almost completely blocked the antagonistic effects of HNG against Aβ₃₁₋₃₅. These results indicate that HNG can dose-dependently prevent against Aβ₃₁₋₃₅-induced impairment in spatial learning and memory of rats, and the neuroprotective effects of HNG might involve the activation of endogenous tyrosine kinase pathway, suggesting that up-regulation of the tyrosine kinase signaling by using HNG might be of great significance for the improvement of cognitive function in AD.

Effects of five flavonoids on expression of Bcl-2 family proteins in apoptosis of myocardiocytes / 中国地方病学杂志

Objective To observe the effects of five flavonoids include rutin(RU),dihydromyricetin(DMY),hesperetin(HP),daidzein(DA)and hydroxysaffor yellow A(HYSA)on myocardiocyte apoptosis induced by H2O2 and to explore their relationships with Keshan disease and the possible mechanism.Methods Primary cultured cardiocytes of neonatal rats were randomly divided into control group,model group,and flavonoids preincubation group.The cardiocyte apoptosis was examined by fluorescent staining,the rates of apoptosis were detected by flow cytometry,the expression of Bcl-2 family proteins associated with apoptosis were observed:by Western blot.Results Compared with model group[(24.33±6.51)%],RU[(13.95±3.80)%],DA[(11.82±3.50)%],HYSA[(12.33±3.78)%]could decreased the rate of apoptosis(P＜0.05).The five flavonoids could up-regulate Bcl-2 expression,down-regulate Bax expression,and increase the Bcl-2/Bax ratio[RU(0.989±0.094),DMY(0.931±0.280),HP(0.980±0.095),DA(1.049±0.092),HYSA(1.031±0.039),vs model(0.490±0.046),the difference had statistical significances(P＜0.05)],but the Bcl-xl did not significantly changed(P＞0.05).Conclusions RU,DMY,HP,DA and HYSA have antiapoptotic effects on cardiomyocyte via regulating Bcl-2 and Bax,which gives us a hint in prevention and treatment of Keshan disease.

Effect of 15-HETE on potassium channels of rabbit pulmonary arterial smooth muscles during hypoxia / 生理学报

This study investigated the role of 15-hydroxyeicosatetraenoic acid (15-HETE) in rabbit pulmonary arterial smooth muscle cells (PASMCs) under hypoxia by using organ bath and whole cell patch-clamp techniques. Neonatal rabbits born into normoxic environment were transferred after first feeding into normal and hypoxic environments with respectively 0.21 and 0.12 fractional inspired oxygen (FiO2). Pulmonary arteries were extracted after 9 d and cut into rings 1.0 approximately 1.5 mm in length for organ bath experiments. Whole cell patch-clamp technique was used to measure the potassium current in the freshly dispersed rabbit PASMCs. The results showed that 15-HETE-induced vasoconstriction was blocked by 4-aminopyridine (5 mmol/L), a Kv channel blocker. The K(ATP) channel blocker glyburide (1 micromol/L) and the BKCa channel blocker tetraethylammonium (10 mmol/L) did not abolish this vasoconstriction. 15-HETE decreased the whole-cell voltage-gated K+ current in the PASMCs. These findings demonstrate that hypoxia blocks Kv channels through a 15-HETE mediated mechanism, leading to PA vasoconstriction.

Expression of 15-Lipoxygenase isoenzymes in the pulmonary arteries during hypoxia / 中国药理学通报

Aim The purpose of this study was to compare the differential expression of 15-lipoxygenase isoenzymes in the pulmonary arteries between normoxia and hypoxia and to explore their roles in the formation of hypoxic pulmomary vasoconstriction. Method Eighteen SD rats were randomly divided into two groups(n=9):the normoxic control group breathing fresh gas and the hypoxic group breeding in animal hypoxic incubator.Immunohistochemical method,in situ hybridization and Western blot were employed to determine certain 15-lipoxygenase isoenzymes which involved in the process of hypoxic pulmonary vasoconstriction.Results ①In normoxic control group,the expression of 15-LO-1 protein was detected in the pulmonary arteries;but the expression of 15-LO-2 protein wasn’t detected.②The expression of 15-LO-1 protein in hypoxic group was much stronger than that in normoxic group (P