- Insight into the negative impact of ionic liquid: A cytotoxicity mechanism of 1-methyl-3-octylimidazolium bromide. [Journal Article]
- EPEnviron Pollut 2018 Aug 11; 242(Pt B):1337-1345
- Ionic liquids (ILs) as a green replacement for volatile organic solvents are increasingly used in large-scale commercial applications. A good understanding of the toxic mechanisms and environmental i...
Ionic liquids (ILs) as a green replacement for volatile organic solvents are increasingly used in large-scale commercial applications. A good understanding of the toxic mechanisms and environmental impact of ILs is neede to reduce the risk for human health and the environment. For this purpose, we aimed to evaluate the possible impacts of 1-methyl-3-octylimidazolium bromide ([C8mim]Br) exposure on human hepatocellular carcinoma (HepG2) cells as to elucidate the cytotoxic mechanism of [C8mim]Br. Biochemical assays revealed that [C8mim]Br exposure altered the protein levels of heat shock protein 70 (HSP70) and HSP90, generally inhibiting total antioxidative capacity (T-AOC), depleting heme oxygenase-1 (HO-1) and increasing transcription and activity of inducible nitric oxide synthase (iNOS) in HepG2 cells. These results indicated that [C8mim]Br may induce biochemical disturbances and cause oxidative stress in HepG2 cells. Moreover, increased phosphorylation of p53, mitochondrial membrane disruption, cyclooxygenase-2 activation, Bcl-2 family protein modulation, cytochrome c and Smac/DIABLO release, and inhibition of apoptosis inhibitory protein-2 (c-IAP2) and survivin were also observed in [C8mim]Br-treated cells, suggesting that [C8mim]Br-induced apoptosis might be mediated by the mitochondrial pathway. Further research showed that [C8mim]Br exposure increased tumour necrosis factor α (TNF-α) transcription and content and promoted the expression of Fas and FasL, indicating that TNF-α and Fas/FasL are involved in the apoptosis induced by [C8mim]Br. Additionally, [C8mim]Br cytotoxicity was partly inhibited by N-acetyl-cysteine (NAC), and NAC reversed [C8mim]Br-mediated mitochondrial dysfunction and blocked apoptotic events by inhibiting the generation of reactive oxygen species (ROS). This work first demonstrated that the ROS-mediated mitochondrial and death receptor-initiated apoptotic pathway is involved in [C8mim]Br-induced HepG2 cell apoptosis.
- Nickel-Catalyzed Stereoselective Diarylation of Alkenylarenes. [Journal Article]
- JAJ Am Chem Soc 2018 Aug 20
- A three-component coupling of aryl bromides, arylboron reagents, and alkenylarenes is presented. The method tolerates a variety of substitution patterns on all of the components. In particular, 1,2-d...
A three-component coupling of aryl bromides, arylboron reagents, and alkenylarenes is presented. The method tolerates a variety of substitution patterns on all of the components. In particular, 1,2-disubstituted alkenylarenes are suitable and undergo highly diastereoselective diarylation.
- Evaluating the Comparative Toxicity of DBP Mixtures from Different Disinfection Scenarios: A New Approach by Combining Freeze-Drying or Rotoevaporation with a Marine Polychaete Bioassay. [Journal Article]
- ESEnviron Sci Technol 2018 Aug 20
- The unintended formation of disinfection byproducts (DBPs) may compromise the safety of drinking water. Since no specified DBPs have been found to be responsible for the overall adverse effects and o...
The unintended formation of disinfection byproducts (DBPs) may compromise the safety of drinking water. Since no specified DBPs have been found to be responsible for the overall adverse effects and over half of total organic halogen (TOX) remains unidentified, DBP mixture toxicity is gaining increasing interest as a potential indicator of how risky drinking water might be. In this study, a new approach to evaluating the toxicity of drinking water DBP mixtures was developed by combining freeze-drying or rotoevaporation pretreatment with an in vivo high-salinity-tolerance bioassay with the embryos of a marine polychaete Platynereis dumerilii. The DBP recoveries by freeze-drying or rotoevaporation were compared with those by commonly applied liquid-liquid-extraction (LLE). For drinking water subjected to typical disinfection processes (i.e., chlorination, chloramination, chlorine dioxide treatment, and ozonation with or without post-chlorination), LLE led to the lowest total organic halogen (TOX) recovery (11-18%) and the loss of all inorganic DBPs, while freeze-drying and rotoevaporation recovered 28-58% and 35-61% of TOX respectively and effectively recovered 81-99% and 85-104% of inorganic DBPs respectively. Thus LLE caused an underestimation of the toxicity of DBP mixtures compared with freeze-drying and rotoevaporation. Besides, the comparative toxicity varied significantly for water samples pretreated with different methods, due to the effect of inorganic DBPs and a synergistic effect of organic and inorganic DBPs. The new approach revealed that the bromide-rich source water disinfected with ozone caused the highest developmental toxicity, followed by those disinfected with chlorine, chlorine dioxide, and chloramine in that order.
- [Effect of sanguinarine on biomechanics of rat airway smooth muscle cells]. [Journal Article]
- SWSheng Wu Yi Xue Gong Cheng Xue Za Zhi 2018 Apr 01; 35(4):583-591
- This study aimed to evaluate the effect of sanguinarine on biomechanical properties of rat airway smooth muscle cells (rASMCs) including stiffness, traction force and cytoskeletal stress fiber organi...
This study aimed to evaluate the effect of sanguinarine on biomechanical properties of rat airway smooth muscle cells (rASMCs) including stiffness, traction force and cytoskeletal stress fiber organization. To do so, rASMCs cultured in vitro were treated with sanguinarine solution at different concentrations (0.005~5 μmol/L) for 12 h, 24 h, 36 h, and 48 h, respectively. Subsequently, the cells were tested for their viability, stiffness, traction force, migration and microfilament distribution by using methylthiazolyldiphenyl-tetrazolium bromide assay, optical magnetic twisting cytometry, Fourier transform traction microscopy, scratch wound healing method, and immunofluorescence microscopy, respectively. The results showed that at concentration below 0.5 μmol/L sanguinarine had no effect on cell viability, but caused dose and time dependent effect on cell biomechanics. Specifically, rASMCs treated with sanguinarine at 0.05 μmol/L and 0.5 μmol/L for 12 and 24 h exhibited significant reduction in stiffness, traction force and migration speed, together with disorganization of the cytoskeletal stress fibers. Considering the essential role of airway smooth muscle cells (ASMCs) biomechanics in the airway hyperresponsiveness (AHR) of asthma, these findings suggest that sanguinarine may ameliorate AHR via alteration of ASMCs biomechanical properties, thus providing a novel approach for asthma drug development.
- The anti-angiogenic potential of (±) gossypol in comparison to suramin. [Journal Article]
- CCytotechnology 2018 Aug 19
- Cotton, a staple fiber that grows around the seeds of the cotton plants (Gossypium), is produced throughout the world, and its by products, such as cotton fibers, cotton-seed oil, and cottonseed prot...
Cotton, a staple fiber that grows around the seeds of the cotton plants (Gossypium), is produced throughout the world, and its by products, such as cotton fibers, cotton-seed oil, and cottonseed proteins, have a variety of applications. Cotton-seed contains gossypol, a natural phenol compound. (±)-Gossypol is a yellowish polyphenol that is derived from different parts of the cotton plant and contains potent anticancer properties. Tumor growth and metastasis are mainly related to angiogenesis; therefore, anti-angiogenic therapy targets the new blood vessels that provide oxygen and nutrients to actively proliferating tumor cells. The aim of the present study was to evaluate the anti-angiogenic potential of (±)-gossypol in vitro. (±)-Gossypol has anti-proliferative effects on cancer cell lines; however, its anti-angiogenic effects on normal cells have not been studied. Anti-proliferative activities of gossypol assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, anti-angiogenic activities using tube formation assay, and cell migration inhibition capability using a wound-healing assay on human umbilical vein endothelial cells (HUVECs) were revealed. (±)-Gossypol displayed the following potent anti-angiogenic activities in vitro: it inhibited the cell viability of HUVECs, it inhibited the migration of HUVECs, and disrupted endothelial tube formation in a dose-dependent manner. In addition, the anti-angiogenic effects of (±)-gossypol were investigated in ovo in a model using a chick chorioallantoic membrane (CAM). Decreases in capillary density were assessed and scored. (±)-Gossypol showed dose-dependent anti-angiogenic effects on CAM. These findings suggest that (±)-gossypol can be used as a new anti-angiogenic agent.
- Catalytic asymmetric synthesis of geminal-dicarboxylates. [Journal Article]
- CSChem Sci 2018 Aug 07; 9(29):6307-6312
- Stereogenic acetals, spiroacetals and ketals are well-studied stereochemical features that bear two heteroatoms at a common carbon atom. These stereocenters are normally found in cyclic structures wh...
Stereogenic acetals, spiroacetals and ketals are well-studied stereochemical features that bear two heteroatoms at a common carbon atom. These stereocenters are normally found in cyclic structures while linear (or acyclic) analogues bearing two heteroatoms are rare. Chiral geminal-dicarboxylates are illustrative, there is no current way to access this class of compounds while controlling the stereochemistry at the carbon center bound to two oxygen atoms. Here we report a rhodium-catalysed asymmetric carboxylation of ester-containing allylic bromides to form stereogenic carbon centers bearing two different carboxylates with high yields and enantioselectivities. The products, which are surprisingly stable to a variety of acidic and basic conditions, can be manipulated with no loss of enantiomeric purity as demonstrated by ring closing metathesis reactions to form chiral lactones, which have been extensively used as building blocks in asymmetric synthesis.
- Activating Autophagy Enhanced the Antitumor Effect of Antibody Drug Conjugates Rituximab-Monomethyl Auristatin E. [Journal Article]
- FIFront Immunol 2018; 9:1799
- CONCLUSIONS: Our data elucidated the critical relationship between autophagy and apoptosis in Rituximab-MMAE-based therapy and highlighted the potential approach for NHL therapy by combined administration of the ADC and autophagy activator.
- Formation of aluminum diphosphonate mesostructures: The effect of aluminum source. [Journal Article]
- JCJ Colloid Interface Sci 2018 Aug 10; 532:718-726
- Mesostructured aluminum phosphonates (AOP-x) bridging with 1,1'-hydroxyl ethylidene groups, including a lamellar mesostructure (AOP-N) with crystalline framework, a well-ordered 2D-hexagonal mesophas...
Mesostructured aluminum phosphonates (AOP-x) bridging with 1,1'-hydroxyl ethylidene groups, including a lamellar mesostructure (AOP-N) with crystalline framework, a well-ordered 2D-hexagonal mesophase (AOP-Cl), and a particle-packed mesostructure (AOP-S), were simply synthesized in the presence of surfactant cetyltrimethylammonium bromide in the ethanol-water system, by choosing Al(NO3)3, AlCl3 and Al2(SO4)3 as the aluminum source, respectively. The crystallinity, morphology, mesophase, and skeletal structure of the as-prepared materials were characterized by XRD, TEM, SEM, 27Al, 31P and 13C MAS NMR, and nitrogen sorption techniques. After calcination under N2 at 350 °C, the calcined AOP-x samples consist of aluminum phosphonate and phosphate, possessing desirable specific surface areas of 116-585 m2/g. The effect of the inorganic counteranions (NO3-, Cl- and SO42-) from the aluminum source on the formation of different AOP-x mesostructures was discussed in terms of their bind strength to the headgroups of the surfactant micelles, suggesting the potential for designed synthesis of non-silica-based mesostructured organic-inorganic hybrid materials.
- Formation and speciation of chlorinated, brominated, and iodinated haloacetamides in chloraminated iodide-containing waters. [Journal Article]
- WRWater Res 2018 Jul 31; 145:103-112
- Haloacetamides (HAMs), an emerging class of disinfection by-products, have received increasing attention due to their elevated cyto- and genotoxicity. However, only limited information is available r...
Haloacetamides (HAMs), an emerging class of disinfection by-products, have received increasing attention due to their elevated cyto- and genotoxicity. However, only limited information is available regarding the iodinated analogues. This study investigated the formation and speciation of iodinated haloacetamides (I-HAMs) and their chlorinated/brominated analogues during the chloramination of bromide and/or iodide-containing waters and a model compound solution over various time periods. The rapid formation of diiodoacetamide (DIAM) was observed during chloramination of three simulated samples, whereas brominated (Br-HAMs) and chlorinated haloacetamides (Cl-HAMs) increased slowly with increasing reaction time. To further understand the differences in the formation of HAMs containing different halogens, experiments with the model compound asparagine in the presence/absence of iodide were conducted. Moreover, iodine utilisation factors and iodine incorporation factors were observed to increase significantly faster and were substantially higher than those of bromine. This implied that, compared with bromide, iodide has substantially greater potential to be transformed to the corresponding HAMs during chloramination, similar to that of other classes of DBPs. That is, I-HAMs formed faster than the other species investigated, including Cl-HAMs and Br-HAMs, in the early reaction stages (0-3 h). The effect of the bromide/iodide ratio (i.e., constant iodide, increasing bromide) on I-HAM formation was also examined. With increasing bromide/iodide ratio, the formation of Br-HAMs increased and dichloroacetamide decreased, but the formation of DIAM was largely unchanged. This was consistent with the constant level of iodide in spite of the increasing bromide. Chlorine and ammonia are applied separately during chloramination in water treatment, so the effect of pre-chlorination (before adding ammonia) on the formation and speciation of I-HAMs during in situ chloramination was also evaluated. Effective mitigation of DIAM formation with in situ chloramination was achieved, and the efficiency improved with increasing pre-chlorination time, where iodide was oxidised to iodate. The HAM-associated cytotoxicity was calculated to determine the change in toxicity at different reaction times, bromide/iodide ratios, and pre-chlorination times. A similar trend as the formation of I-HAMs was observed, which increased rapidly in the first 3 h, but decreased somewhat subsequently. When the bromide/iodide ratio and pre-chlorination time was increased, the calculated toxicity of the HAMs increased (due to more formation of Br-HAMs and less Cl-HAMs) and decreased (due to less DIAM formation), respectively.
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- The novel peripherally active cannabinoid type 1 and serotonin type 3 receptor agonist AM9405 inhibits gastrointestinal motility and reduces abdominal pain in mouse models mimicking irritable bowel syndrome. [Journal Article]
- EJEur J Pharmacol 2018 Aug 16
- The endocannabinoid system (ECS) plays a crucial role in numerous physiological processes in the central and peripheral nervous systems. In the gastrointestinal (GI) tract, selective cannabinoid (CB)...
The endocannabinoid system (ECS) plays a crucial role in numerous physiological processes in the central and peripheral nervous systems. In the gastrointestinal (GI) tract, selective cannabinoid (CB) receptor agonists exert potent inhibitory actions on motility and pain signalling. In the present study, we used mouse models of diarrhea, hypermotility, and abdominal pain to examine whether a novel synthetic CB1 receptor agonist AM9405 [(2-(2,6-dihydroxy-4-(2-methyloctan-2-yl)phenyl)-1,3-dimethyl-1H-benzo[d]imidazol-3-ium bromide); also known as GAT379] exhibits effects of potential therapeutic relevance. AM9405 significantly slowed mouse intestinal motility in physiological conditions. Moreover, AM9405 reversed hypermotility and reduced pain in mouse models mimicking symptoms of functional GI disorders, such as stress-induced diarrhoea and writhing test. Interestingly, some of the effects of AM9405 were blocked by a 5-HT3 antagonist suggesting interaction with 5-HT3 receptors. In our study we show that combining CB1 agonism with 5-HT3 agonism may alter physiological functions and experimental pathophysiologies in a manner that make such compounds promising drugs for the future treatment of functional GI disorders.