Design,synthesis, and antitumor evaluation of quinoline‐imidazole derivatives

A series of compounds bearing quinoline‐imidazole ( 8a–e , 9a–e , 10a–e , 11a–e , and 12a–e ) not reported previously were designed and synthesized. The target compounds were evaluated for antitumor activity against A549, PC‐3, HepG2, and MCF‐7 cells by the MTT method, with NVP‐BEZ235 being the positive control. Most compounds showed moderate activity and compound 12a showed the best activity against HepG2, A549, and PC‐3 cells, with half‐maximal inhibitory concentration (IC₅₀) values of 2.42 ± 1.02 µM, 6.29 ± 0.99 µM, and 5.11 ± 1.00 µM, respectively, which was equal to NVP‐BEZ235 (0.54 ± 0.13 µM, 0.36 ± 0.06 µM, 0.20 ± 0.01 µM). Besides, the IC₅₀ value of 12a against the cell line WI‐38 (human fetal lung fibroblasts) was 32.8 ± 1.23 µM, indicating that the target compounds were selective for cancer cells. So, 11a and 12a were evaluated against PI3Kα and mTOR to find out if the compounds acted through the PI3K‐Akt‐mTOR signal transduction pathway. The inhibition ratios to PI3Kα and mTOR were slightly lower than that of NVP‐BEZ235, suggesting there may be some other mechanisms of action. The structure–activity relationships and docking study of 11a and 12a revealed that the latter was superior. Moreover, the target compounds showed better in vitro anticancer activity when the C‐6 of the quinoline ring was replaced by a bromine atom.

     

Synthesis and biological evaluation of phloroglucinol derivatives possessing α‐glycosidase,acetylcholinesterase, butyrylcholinesterase,carbonic anhydrase inhibitory activity

A series of novel phloroglucinol derivatives were designed, synthesized, characterized spectroscopically and tested for their inhibitory activity against selected metabolic enzymes, including α‐glycosidase, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and human carbonic anhydrase I and II (hCA I and II). These compounds displayed nanomolar inhibition levels and showed K_i values of 1.14–3.92 nM against AChE, 0.24–1.64 nM against BChE, 6.73–51.10 nM against α‐glycosidase, 1.80–5.10 nM against hCA I, and 1.14–5.45 nM against hCA II.

     

Design,synthesis, biological evaluations,molecular docking,and in vivo studies of novel phthalimide analogs

A series of novel phthalimide analogs containing an indole or brominated indole moiety were synthesized and their antimicrobial activity was evaluated. Compound 8 showed a broad spectrum activity, revealing 53–67% of erythromycin activity on the tested bacteria and 60–70% of miconazole activity on the tested fungi. Anticancer activity was evaluated on the cell lines HepG2, MCF‐7, A549, H1299, and Caco2. The results revealed that the new phthalimide analog 8 has broad‐spectrum anticancer activity toward all the tested cancer cell lines, followed by compound 11 , which showed good activity toward all the tested cell lines except for MCF‐7. The ability of the promising analogs 5 , 8 , and 11 to bind to topoisomerase II DNA gyrase was investigated. Caspase‐3 activation and Bcl‐2 assay of the best active derivatives 8 , 11 in addition to compound 5 were evaluated. The antifibrotic activity was studied in an in vivo model and the histopathological studies revealed that treatment with the new compound 8 improved the fibrotic liver tissues to normality.

     

Effect of residual doxycycline concentrations on resistance selection and transfer in porcine commensal Escherichia coli

Pig feed may contain various levels of antimicrobial residues due to cross-contamination. A previous study showed that a 3% carry-over level of doxycycline (DOX) in the feed results in porcine faecal concentrations of approximately 4?mg/L.The aim of this study was to determine the effect of residual DOX concentrations (1 and 4?mg/L) in vitro on selection of DOX–resistant porcine commensal Escherichia coli and transfer of their resistance plasmids.Three different DOX–resistant porcine commensal E. coli strains and their plasmids were characterised. These strains were each brought in competition with a susceptible strain in a medium containing 0, 1 and 4?mg/L DOX. Resistant bacteria, susceptible bacteria and transconjugants were enumerated after 24?h and 48?h.The tet(A)–carrying plasmids showed genetic backbones that are also present among human E. coli isolates. Ratios of resistant to susceptible bacteria were significantly higher at 1 and 4?mg/L DOX compared with the blank control, but there was no significant difference between 1 and 4?mg/L. Plasmid transfer frequencies were affected by 1 or 4?mg/L DOX in the medium for only one of the resistance plasmids.In conclusion, DOX concentrations of 1 and 4?mg/L can select for resistant E. coli in vitro. Further research is needed to determine the effect of these concentrations in the complex environment of the porcine intestinal microbiota.     

Can we increase the speed and efficacy of antidepressant treatments? Part II. Glutamatergic and RNA interference strategies

In the second part we focus on two treatment strategies that may overcome the main limitations of current antidepressant drugs. First, we review the experimental and clinical evidence supporting the use of glutamatergic drugs as fast-acting antidepressants. Secondly, we review the involvement of microRNAs (miRNAs) in the pathophysiology of major depressive disorder (MDD) and the use of small RNAs (e.g.., small interfering RNAs or siRNAs) to knockdown genes in monoaminergic and non-monoaminergic neurons and induce antidepressant-like responses in experimental animals.The development of glutamatergic agents is a promising venue for antidepressant drug development, given the antidepressant properties of the non-competitive NMDA receptor antagonist ketamine. Its unique properties appear to result from the activation of AMPA receptors by a metabolite [(2 S,6 S;2 R,6 R)-hydroxynorketamine (HNK)] and mTOR signaling. These effects increase synaptogenesis in prefrontal cortical pyramidal neurons and enhance serotonergic neurotransmission via descending inputs to the raphe nuclei. This view is supported by the cancellation of ketamine's antidepressant-like effects by inhibition of serotonin synthesis.We also review existing evidence supporting the involvement of miRNAs in MDD and the preclinical use of RNA interference (RNAi) strategies to target genes involved in antidepressant response. Many miRNAs have been associated to MDD, some of which e.g., miR-135 targets genes involved in antidepressant actions. Likewise, SSRI-conjugated siRNA evokes faster and/or more effective antidepressant-like responses. Intranasal application of sertraline-conjugated siRNAs directed to 5-HT_1A receptors and SERT evoked much faster changes of pre- and postsynaptic antidepressant markers than those produced by fluoxetine.     

丹酚酸B调控pSmad3C/pSmad3L发挥抗肝纤维化-肝细胞癌作用

目的观察丹酚酸B(salvianolic acid B,Sal B)对二乙基亚硝胺(diethylnitrosamine,DEN)诱导小鼠肝纤维化-肝细胞癌进程的影响,并探讨Sal B经由p Smad3C/p21介导的抑癌信号、p Smd3L/PAI-1/c-Myc介导的促肝纤维化-肝癌信号转换机制。方法昆明种♂小鼠100只,随机分组,DEN诱导小鼠肝纤维化-肝细胞癌模型,不同剂量Sal B(15、30mg·kg^-1·d^-1,ig)及阳性药秋水仙碱(0.2 mg·kg^-1·d^-1,ig)干预。于造模第12周、第16周分批处死小鼠,肝脏活检,苏木精-伊红(HE)染色、Van Gieson(VG)染色观察肝组织病理学特征,Western blot法检测肝组织中p Smad3C、p S-mad3L、p21、纤溶酶原激活物抑制剂-1(plasminogen activator inhibitor 1,PAI-1)及c-Myc蛋白表达。结果正常组肝脏表面光滑、质地柔软,模型组第12周时肝脏表面粗糙、质地变硬,第16周时肝脏表面可见弥漫性结节、质地坚硬;而丹酚酸B干预组以上病变明显改善。HE及VG染色显示,正常组肝组织结构正常,模型组第12周时肝组织炎细胞浸润、胶原纤维增生,形成假小叶结构;第16周时肝小叶结构紊乱,细胞核变大、分裂相增多、异型性明显;Sal B干预组肝组织病变程度明显减轻。Western blot结果显示,正常组肝组织中p Smad3C、p Smad3L、PAI-1表达均较少,p21、c-Myc几乎不表达;模型组第12周时肝组织中p Smad3C无明显变化,p S-mad3L、PAI-1、p21表达增多,第16周时p Smad3C、p Smad3L、p21、PAI-1、c-Myc表达皆有增加;而Sal B干预组第12周时p Smad3C、p21表达明显增加,p Smad3L、PAI-1蛋白水平明显降低,第16周时p Smad3C表达明显增加,p21几乎无变化,p Smad3L、PAI-1、c-Myc表达明显降低。结论Sal B延缓DEN诱导的小鼠肝纤维化-肝细胞癌进程,其机制可能与调控p Smad3C/p21、p Smad3L/PAI-1/c-Myc信号转换有关。     

斑马鱼皮肤损伤模型的建立及分子机制

目的以皮肤荧光转基因斑马鱼(ktr4:NTR-h Kik GR)为实验动物,研究长春新碱对皮肤细胞的损伤作用及其分子机制,建立皮肤损伤模型。方法取受精后24 h皮肤荧光斑马鱼胚胎,将脱膜后的胚胎分别置于0.01~0.04 mmol·L^-1不同浓度的长春新碱中,24 h后采用荧光显像的方法对斑马鱼皮肤荧光斑点进行计数和统计处理;同时对鱼体细胞死亡情况进行TUNEL试剂盒检测,确定其皮肤细胞死亡的水平;利用蛋白免疫印迹的方法对各组斑马鱼胚胎的caspase-3、KRT4及p53表达水平进行检测。结果在长春新碱与斑马鱼胚胎共同孵育24 h后,0.02、0.04 mmol·L^-1长春新碱明显引起斑马鱼荧光皮肤细胞减少(P<0.01);TUNEL检测表明,长春新碱与对照组比较能明显引起斑马鱼皮肤细胞凋亡;Western bolt分析显示,0.02、0.04 mmol·L^-1长春新碱能诱导斑马鱼胚胎caspase-3和p53表达增加(P<0.01),同时高浓度的长春新碱可使皮肤角蛋白KRT4表达明显减少(P<0.01)。结论利用长春新碱引起斑马鱼皮肤损伤,该局部毒性作用可作为皮肤损伤的造模新方法。     

槲皮素通过影响吲哚胺-2,3-双加氧酶活性抑制HeLa细胞增殖的研究

目的研究槲皮素抑制人宫颈癌HeLa细胞增殖的机制。方法采用CCK-8法检测细胞增殖;流式细胞术检测细胞周期的变化;运用紫外可见分光光度计测定OD₄₈₀值,反映色氨酸代谢及犬尿氨酸的生成情况;qPCR法检测IDO1的mRNA表达;表达、纯化IDO1蛋白并进行体外酶活性反应,用高效液相色谱法检测色氨酸和犬尿氨酸的含量变化。结果槲皮素抑制HeLa细胞的增殖,引起G0/G1细胞周期阻滞;槲皮素抑制色氨酸的代谢;槲皮素能够明显抑制IDO1的体外酶催化活性,但不影响IDO1的表达;外源性添加色氨酸的代谢产物犬尿氨酸可以逆转槲皮素引起的细胞增殖抑制。结论槲皮素可能通过抑制IDO1的酶催化活性,影响细胞色氨酸的代谢,这可能是槲皮素发挥其抗宫颈癌HeLa细胞增殖作用的机制之一。     

黄芪多糖通过抑制NF-κB和JNK信号通路减轻LPS诱导的小鼠心肌细胞凋亡

目的研究黄芪多糖(Astragalus polysaccharide,APS)对脂多糖(lipopolysaccharide,LPS)诱导的小鼠心肌细胞凋亡的影响,并探讨其作用机制。方法体外实验采用H9c2细胞预先给予APS,30 min后加入LPS(1 mg·L^-1)共孵育24 h,建立心肌细胞凋亡模型。体内实验采用SPF级昆明小鼠预防性给予APS 14 d后,腹腔注射LPS(10 mg·kg^-1)建立心肌细胞凋亡模型。8 h后采用超声心动测定小鼠心脏射血分数(EF)、左心室缩短分数(FS)等;TUNEL测心肌细胞凋亡;ELISA检测血清中IL^-1β、TNF-α含量;Western blot检测组织和体外心肌细胞中JNK、NF-κB信号通路及Bcl-2家族、caspase-3相关蛋白表达。结果 LPS能明显抑制小鼠的左心室收缩功能;促使心肌细胞凋亡;增加血清中IL^-1β、TNF-α,心肌细胞中JNK、p-JNK、Bax、caspase-3,胞核中NF-κB蛋白浓度;降低Bcl-2和胞质中NF-κB、IκB-α蛋白浓度。APS能明显保护LPS诱导的小鼠心肌收缩功能,减少心肌细胞凋亡;减少血清中IL^-1β、TNF-α,心肌组织细胞中p-JNK、Bax、caspase-3和胞核NF-κB蛋白含量;相对增加Bcl-2和胞质中NF-κB、IκB-α蛋白含量。而JNK蛋白表达无明显变化。结论 APS通过抑制NF-κB和JNK信号通路,减轻LPS诱导的小鼠心肌细胞凋亡。