The genotoxicity impact of heavy metals on the <i>Escherichia Coli</i>

In the present work, the genotoxicity of Hg2+, Ag+, Cr6+, Ni2+, Pb2+, Co2+, Mn2+, Zn2+, and Cr3+ was investigated via a quantitative toxicogenomics assay, in order to understand the toxic mechanism of heavy metals with greater depth. Under the experimental conditions, Hg2+, Ag+, and Cr6+ behaved more serious toxic impact on the expression of functional genes (eg., oxyR, katG, grxA, osmE, emrE, dinG) than Ni2+, Pb2+, Co2+, Mn2+, Zn2+, and Cr3+, while the protein, oxidative, and membrane stress response pathways were more sensitive to the toxicity of Hg2+, Ag+, and Cr6+ than the DNA and general stress response pathways. Comparing with the other kinds of heavy metals, Ni2+, Pb2+, Co2+, and Mn2+ altered the expression of functional genes (uvrY, recX, mutY, and sbmC) related to the DNA stress response pathways more seriously, while Zn2+ and Cr3+ changed the expression of the functional genes (yfjG, ydgL, ssrA, and osmC) associated with the general stress response pathway more significantly. Meanwhile, the toxicity of Ni2+, Pb2+, Co2+, and Mn2+ were slightly higher than that of Zn2+ and Cr3+ in terms of the total value of transcriptional effect level Index (TELI) via detecting the promoter activities of different functional genes. In addition, to survive from the toxicity of heavy metals, the expression of multidrug efflux genes (ydgL, cyoA, emrA, and emrE) and toxicity-resistant genes (Ion, dnaJ, clpB, mutY, dnaK, rpoD, sbmC) mainly functioned.</p

High-Efficiency Simultaneous Oxidation of Organoarsenic and Immobilization of Arsenic in Fenton Enhanced Plasma System

Roxarsone (ROX), an organoarsenic compound serving as a common feeding additive, is heavily utilized in the agricultural field and brings about the potential risks of toxic inorganic arsenic contamination in the ambient environment. In this study, the applicability of glow discharge plasma (GDP) for simultaneous oxidation of organoarsenic and immobilization of arsenic is unprecedentedly evaluated. The results show that ROX can be effectively oxidized to inorganic arsenic, and this performance is evidently dependent on energy input. Adding Fe­(II) can significantly enhance the oxidation of ROX mainly because of the additional production of ^•OH via Fenton reaction in GDP, accompanied by which the generated arsenic can be simultaneously immobilized in one process. The immobilization of arsenic can be favorably obtained at pH 4.0–6.0 and Fe­(II) concentration ranging from 500 to 1000 μM. On the basis of the mineral compositions and analysis (XRD/FTIR/XPS) of precipitate, a mechanism can be proposed that the oxidation of Fe­(II) by H₂O₂ generated in situ in GDP significantly accelerates ROX transformation to the ionic As­(V), which can immediately precipitate with Fe­(III) ions or be adsorbed on the ferric oxyhydroxides, forming amorphous ferric arsenate-bearing ferric oxyhydroxides. As such, the present study offer a new recipe for rapid decontamination of organoarsenic pollutants, in which the hypertoxic species can be effectively removed from the wastewater

Diastereoselective Synthesis of CF₃‑Containing Vicinal Diamines

The highly diastereoselective synthesis of CF₃-containing vicinal diamines by a convenient two-step procedure without the need to isolate the intermediate products is described

Design and Synthesis of Fluorinated Amphiphile as ¹⁹F MRI/Fluorescence Dual-Imaging Agent by Tuning the Self-Assembly

Both ¹⁹F MRI and optical imaging are powerful noninvasive molecular imaging modalities in biomedical applications. To integrate these two complementary imaging modalities, the design and synthesis of a novel ¹⁹F MRI/fluorescence dual-modal imaging agent is reported herein. Through Sonogashira coupling reaction between the fluorinated phenylacetylene and 1,2,4,5-tetraiodobenzene, a fluorophore with 48 symmetrical fluorines at its periphery was constructed with high efficacy. High aqueous solubility was achieved by PEGylation of the fluorophore with monodisperse PEGs. However, an unexpected self-assembly of the PEGylated amphiphilic fluorophore in water “turned off” the ¹⁹F NMR signal. However, hydrogenation of the triple bonds or introduction of branched monodisperse PEGs was able to efficiently tune the self-assembly, resulting in the “turning on” of the ¹⁹F NMR signal. One of these amphiphiles combines the advantages of label-free fluorescence, high ¹⁹F MRI sensitivity, biocompatibility, and excellent aqueous solubility. The results demonstrate the great potential of such amphiphiles for real-time ¹⁹F MRI and fluorescence dual-modality imaging

Effects of Chitin Whiskers on Physical Properties and Osteoblast Culture of Alginate Based Nanocomposite Hydrogels

Novel nanocomposite hydrogels composed of polyelectrolytes alginate and chitin whiskers with biocompatibility were successfully fabricated based on the pH-induced charge shifting behavior of chitin whiskers. The chitin whiskers with mean length and width of 300 and 20 nm were uniformly dispersed in negatively charged sodium alginate aqueous solution, leading to the formation of the homogeneous nanocomposite hydrogels. The experimental results indicated that their mechanical properties were significantly improved compared to alginate hydrogel and the swelling trends were inhibited as a result of the strong electrostatic interactions between the chitin whiskers and alginate. The nanocomposite hydrogels exhibited certain crystallinity and hierarchical structure with nanoscale chitin whiskers, similar to the structure of the native extracellular matrix. Moreover, the nanocomposite hydrogels were successfully applied as bone scaffolds for MC3T3-E1 osteoblast cells, showing their excellent biocompatibility and low cytotoxicity. The results of fluorescent micrographs and scanning electronic microscope (SEM) images revealed that the addition of chitin whiskers into the nanocomposite hydrogels markedly promoted the cell adhesion and proliferation of the osteoblast cells. The biocompatible nanocomposite hydrogels have potential application in bone tissue engineering

Systems biology approaches for understanding metabolic differences using ‘multi-omics’ profiling of metabolites in mice fed with honey and mixed sugars

Honey is proposed to be the oldest natural sweetener and it is a standard component of several dietary patterns. Recent evidence suggests that replacing sugars, such as fructose, with honey has potential health benefits. In this study, we determined the effects of honey supplementation in mice on cardiometabolic and inflammatory markers and changes in gut microbiota and metabolomic profiles. We compared mice fed a honey diet (1 or 2 g/kg) with those fed an analog diet (mixed fructose, glucose, and sucrose (FSG) solutions) at exact dosages for one month. We found the same blood glucose fluctuating trends for honey- and FGS-fed mice. The honey diets resulted in less weight gain and fewer ballooned hepatocytes. Additionally, honey diets decreased the total serum cholesterol and TNF-α and increased the antioxidant enzyme activity. Each diet type was associated with distinct gut microbiota and metabolomics profiles. Systems biology analysis revealed that Lactococcus spp., Lachnospiraceae spp., and oleamide had the strongest correlations with lipid metabolic networks. Although in an animal model, this study provides a good understanding of the potential benefits of choosing honey rather than mixed sugars in regular dietary patterns.</p

Design, synthesis and biological evaluation of chrysin benzimidazole derivatives as potential anticancer agents

<p>A series of chrysin benzimidazole derivatives were synthesised and evaluated for their anticancer activity in the search for potential anticancer agents. Among them, compound <b>18</b> displayed the most potent anti-proliferative activity against MFC cells with IC₅₀ values of 25.72 ± 3.95 μM. The flow cytometry results displayed that compound <b>18</b> induced apoptosis of MFC cells in a dose-dependent manner and caused the cell cycle to be arrested in the G0/G1 phase. Furthermore, the preliminary anticancer activity <i>in vivo</i> was also studied in tumour-bearing mice, and the compound <b>18</b> exerted good inhibition effect on tumour growth. These results suggested that compound <b>18</b> had good anticancer activity, which could be a potential anticancer agent after further optimisation and evaluation.</p

Synthesis and evaluation of antitumour activity <i>in vitro</i> and <i>in vivo</i> of chrysin salicylate derivatives

<p>A series of chrysin salicylate derivatives as potential antitumour agents were synthesised and evaluated their antitumour activities <i>in vitro</i> and <i>in vivo</i>. Most of the compounds exhibited moderate to good activities against MCF-7 cells, HepG2 cells, MGC-803cells and MFC cells. Among them, compound <b>3f</b> showed the most potent activity against MGC-803 cells and MFC cells with IC₅₀ values of 23.83 ± 3.68 and 27.34 ± 5.21 μM, respectively. The flow cytometry assay reconfirmed that compound <b>3f</b> promoted the occurrence of tumour cells’ G1/S block under the inhibiting effect of compound <b>3f</b>. Compound <b>3f</b> possessed higher antitumour efficacy in tumour-bearing mice, compared with the positive control 5-Fu and the blank control saline.</p