Discovery of new quinolines as potent colchicine binding site inhibitors: design,synthesis, docking studies,and anti-proliferative evaluation

Discovering of new anticancer agents with potential activity against tubulin polymerisation is still a promising approach. Colchicine binding site inhibitors are the most relevant anti-tubulin polymerisation agents. Thus, new quinoline derivatives have been designed and synthesised to possess the same essential pharmacophoric features of colchicine binding site inhibitors. The synthesised compounds were tested in vitro against a panel of three human cancer cell lines (HepG-2, HCT-116, and MCF-7) using colchicine as a positive control. Comparing to colchicine (IC₅₀ = 7.40, 9.32, and 10.41 µM against HepG-2, HCT-116, and MCF-7, respectively), compounds 20, 21, 22, 23, 24, 25, 26, and 28 exhibited superior cytotoxic activities with IC₅₀ values ranging from 1.78 to 9.19 µM. In order to sightsee the proposed mechanism of anti-proliferative activity, the most active members were further evaluated in vitro for their inhibitory activities against tubulin polymerisation. Compounds 21 and 32 exhibited the highest tubulin polymerisation inhibitory effect with IC₅₀ values of 9.11 and 10.5 nM, respectively. Such members showed activities higher than that of colchicine (IC₅₀ = 10.6 nM) and CA-4 (IC₅₀ = 13.2 nM). The impact of the most promising compound 25 on cell cycle distribution was assessed. The results revealed that compound 25 can arrest the cell cycle at G2/M phase. Annexin V and PI double staining assay was carried out to explore the apoptotic effect of the synthesised compounds. Compound 25 induced apoptotic effect on HepG-2 thirteen times more than the control cells. To examine the binding pattern of the target compounds against the tubulin heterodimers active site, molecular docking studies were carried out.     

Metaproteomic analysis of a winter to spring succession in coastal northwest Atlantic Ocean microbial plankton

In this study, we used comparative metaproteomics to investigate the metabolic activity of microbial plankton inhabiting a seasonally hypoxic basin in the Northwest Atlantic Ocean (Bedford Basin). From winter to spring, we observed a seasonal increase in high-affinity membrane transport proteins involved in scavenging of organic substrates; Rhodobacterales transporters were strongly associated with the spring phytoplankton bloom, whereas SAR11 transporters were abundant in the underlying waters. A diverse array of transporters for organic compounds were similar to the SAR324 clade, revealing an active heterotrophic lifestyle in coastal waters. Proteins involved in methanol oxidation (from the OM43 clade) and carbon monoxide (from a wide variety of bacteria) were identified throughout Bedford Basin. Metabolic niche partitioning between the SUP05 and ARCTIC96BD-19 clades, which together comprise the Gamma-proteobacterial sulfur oxidizers group was apparent. ARCTIC96BD-19 proteins involved in the transport of organic compounds indicated that in productive coastal waters this lineage tends toward a heterotrophic metabolism. In contrast, the identification of sulfur oxidation proteins from SUP05 indicated the use of reduced sulfur as an energy source in hypoxic bottom water. We identified an abundance of Marine Group I Thaumarchaeota proteins in the hypoxic deep layer, including proteins for nitrification and carbon fixation. No transporters for organic compounds were detected among the thaumarchaeal proteins, suggesting a reliance on autotrophic carbon assimilation. In summary, our analyses revealed the spatiotemporal structure of numerous metabolic activities in the coastal ocean that are central to carbon, nitrogen and sulfur cycling in the sea.     

Changes in Holstein cow milk and serum proteins during intramammary infection with three different strains of Staphylococcus aureus

Background

Horses develop recurrent airway obstruction (RAO) that resembles human bronchial asthma. Differentiated primary equine bronchial epithelial cells (EBEC) in culture that closely mimic the airway cells in vivo would be useful to investigate the contribution of bronchial epithelium in inflammation of airway diseases. However, because isolation and characterization of EBEC cultures has been limited, we modified and optimized techniques of generating and culturing EBECs from healthy horses to mimic in vivo conditions.

Results

Large numbers of EBEC were obtained by trypsin digestion and successfully grown for up to 2 passages with or without serum. However, serum or ultroser G proved to be essential for EBEC differentiation on membrane inserts at ALI. A pseudo-stratified muco-ciliary epithelium with basal cells was observed at differentiation. Further, transepithelial resistance (TEER) was more consistent and higher in P₁ cultures compared to P₀ cultures while ciliation was delayed in P₁ cultures.

Conclusions

This study provides an efficient method for obtaining a high-yield of EBECs and for generating highly differentiated cultures. These EBEC cultures can be used to study the formation of tight junction or to identify epithelial-derived inflammatory factors that contribute to lung diseases such as asthma.     

Genome sequence of herpes simplex virus 1 strain KOS

Herpes simplex virus type 1 (HSV-1) strain KOS has been extensively used in many studies to examine HSV-1 replication, gene expression, and pathogenesis. Notably, strain KOS is known to be less pathogenic than the first sequenced genome of HSV-1, strain 17. To understand the genotypic differences between KOS and other phenotypically distinct strains of HSV-1, we sequenced the viral genome of strain KOS. When comparing strain KOS to strain 17, there are at least 1,024 small nucleotide polymorphisms (SNPs) and 172 insertions/deletions (indels). The polymorphisms observed in the KOS genome will likely provide insights into the genes, their protein products, and the cis elements that regulate the biology of this HSV-1 strain.     

Effect of recombinant erythropoietin on ischemia–reperfusion-induced apoptosis in rat liver

Ischemia–reperfusion (I/R) cannot be avoided in liver transplantation procedures, and apoptosis is a central mechanism of cell death after liver reperfusion. Protective effect of recombinant erythropoietin (rhEPO) on liver apoptosis has not been clearly investigated. This work investigated intraportal (IP) rhEPO-protective effect in a rat model of hepatic I/R-induced apoptosis and its appropriated time and dose of administration. Eight groups were included (n = 10/group): sham-operated, I/R (45 min ischemia and 2 h reperfusion), preconditioned rhEPO I/R (24 h or 30 min before ischemia), and postconditioned rhEPO I/R (before reperfusion) using two different rhEPO doses (1,000 and 5,000 IU/kg). When compared with the sham-operated group, the I/R group showed significant increase of serum levels of aspartate and alanine aminotransferases (AST, ALT), hepatic caspase-9 activity(894.99 ± 176.90 relative fluorescence units (RFU)/mg/min versus 458.48 ± 82.96 RFU/mg/min), and Fas ligand (FasL) expression, histopathological damages, and significant decrease in the antiapoptotic Bcl-xL/apoptotic Bax ratio(0.38 ± 0.21 versus 3.35 ± 0.77) rhEPO-improved ALT and AST but failed to reduce FasL expression in all groups compared with the I/R group. Thirty minutes and 24 h preconditioning with rhEPO (1,000 IU/kg) increased Bcl-xL/Bax ratio and reduced caspase-9 activity, and the same effect was observed when higher dose was given 24 h before ischemia. Preconditioning was more effective than postconditioning in improving caspase-9 activity, and no dose-dependent effect was observed. In conclusion, single IP rhEPO injection 30 min before ischemia has an advantage over rhEPO postconditioning in improving post-hepatic I/R-induced apoptosis with no additional time- and dose-dependent effects which may provide potentially useful guide in liver transplantation procedures.     

Azole antimicrobial pharmacophore-based tetrazoles: Synthesis and biological evaluation as potential antimicrobial and anticonvulsant agents

The azole pharmacophore is still considered a viable lead structure for the synthesis of more efficacious and broad spectrum antimicrobial agents. Potential antibacterial and antifungal activities are encountered with some tetrazoles. Therefore, this study presents the synthesis and antimicrobial evaluation of a new series of substituted tetrazoles that are structurally related to the famous antimicrobial azole pharmacophore. A detailed discussion of the structural elucidation of some of the newly synthesized compounds is also described. Antimicrobial evaluation revealed that twenty compounds were able to display variable growth inhibitory effects on the tested Gram positive and Gram negative bacteria with special efficacy against the Gram positive strains. Meanwhile, six compounds exhibited moderate antifungal activity against Candida albicans and Aspergillus fumigatus. Structurally, the antibacterial activity was encountered with tetrazoles containing a phenyl substituent, while the obtained antifungal activity was confined to the benzyl variants. Compounds 16, 18, 24 and 27 were proved to be the most active antibacterial members within this study with a considerable broad spectrum against all the Gram positive and negative strains tested. A distinctive anti-Gram positive activity was displayed by compound 18 against Staphylococcus aureus that was equipotent to ampicillin (MIC 6.25 μg/mL).On the other hand, twelve compounds were selected to be screened for their preliminary anticonvulsant activity against subcutaneous metrazole (ScMet) and maximal electroshock (MES) induced seizures in mice. The results revealed that five compounds namely; 3, 5, 13, 21, and 24 were able to display noticeable anticonvulsant activity in both tests at 100 mg/kg dose level. Compounds 5 and 21 were proved to be the most active anticonvulsant members in this study with special high activity in the ScMet assay (% protection: 100% and 80%, respectively).     

Efficacy of two intervention approaches on functional walking capacity and balance in children with Duchene muscular dystrophy

Objectives:Children with Duchene muscular dystrophy have weak muscles, which may impair postural adjustments. These postural adjustments are required for gait and dynamic balance during the daily living activities. The aim was to compare between the effect of bicycle ergometer versus treadmill on functional walking capacity and balance in children with Duchenne muscular dystrophy.Methods:Thirty boys aged from 6 to 10 years old diagnosed as Duchene muscular dystrophy participated in this study. Children were assigned randomly into two groups (A&B). Children in group (A) underwent a designed program of physical therapy plus aerobic exercise training in form of bicycle ergometer while, group (B) received the same program as group (A) and aerobic exercise training by treadmill for one hour, at three times a week for three successive months. Functional walking capacity and balance were assessed before and after treatment by using the 6-minute walk test and Biodex balance system equipment respectively.Results:The post treatment results revealed significant difference in all measured variables (P<0.05) as compared with its pre-treatment results. Post-treatment values indicated that there was a significant difference in all measured variables in favor of group B.Conclusions:treadmill training as an aerobic exercise can improve walking capacity and balance more effectively than bicycle ergometer in children with Duchenne muscular dystrophy.     

Formulation and Evaluation of PLA and PLGA In Situ Implants Containing Secnidazole and/or Doxycycline for Treatment of Periodontitis

The purpose of this study is to formulate in situ implants containing doxycycline hydrochloride and/or secnidazole that could be used in the treatment of periodontitis by direct periodontal intrapocket administration. Biodegradable polymers [poly (lactide) (PLA) and poly (lactide-co-glycolide) (PLGA)], each polymer in two concentrations 25%w/w, 35%w/w were used to formulate the in situ implants. The rheological behavior, in vitro drug release and the antimicrobial activity of the prepared implants were evaluated. Increasing the concentration of each polymer increases the viscosity and decreases the percent of the drugs released after 24 h. PLA implants showed a slower drugs release rate than PLGA implants in which the implants composed of 25% PLGA showed the fastest drugs release. The in vitro drug release and antimicrobial activity results were compared with results of Atridox. Results revealed that the pharmaceutical formulation based on 25% PLGA containing secnidazole and doxycycline hydrochloride has promising activity in treating periodontitis in comparison with Atridox.