The extraction,antioxidant and against β-amyloid induced toxicity of polyphenols from Alsophila spinulosa leaves

Alsophila spinulosa is a tree-like fern, and many evidences suggested that plant polyphenols had the potential therapeutic for Alzheimer s disease (AD). Herein, polyphenols (ASP) was isolated from A. spinulosa leaves and its major constituent were isoorientin and vitexin. ASP displayed excellent antioxidant activity and obvious anti-lipid peroxidation capacity in vitro. ASP improved the survival rate of C. elegans under high temperature by enhancing the antioxidant enzymes activities and decreasing the lipid peroxidation level. Moreover, ASP alleviated β-amyloid (Aβ) induced paralysis and reduced Aβ deposition, decreased reactive oxygen species (ROS) accumulation and improved the level of skn-1 mRNA. In addition, ASP decreased the levels of pdk-1 and akt-1 mRNA in P13K/AKT signaling pathway. In conclusion, ASP may be a potential ingredient for the alleviation of AD.     

Antioxidant enzymes activity in subcellular fraction of freshwater prawnsM. malcolmsonii andM. lamarrei lamarrei

Subcellular distribution of Superoxide dismutase (SOD), catalase (CAT), selenium (SC) dependent glutathione peroxidase, and Se-independent glutathione peroxidase (GSH-Px) activities were detected in different tissues (hepatopancreas, muscle, and gill) of freshwater prawnsMacrobrachium malcolmsonii andMacrobrahium lamarrei lamarrei. CAT and SOD were found almost equally between the mitochondrial and cytosolic fraction. Both Se-dependent and Se-independent GSH-Px activities were mainly found in cytosolic fraction.     

Millettia ferruginea extract attenuates cisplatin-induced alterations in kidney functioning,DNA damage,oxidative stress,and renal tissue morphology

This study aimed to investigate the beneficial role of Millettia ferruginea extract (MF) in preventing cisplatin (Cisp) induced nephrotoxicity in rats. A total of 55 metabolites were identified using LC-MS analysis. The in vivo results indicated that MF pretreatment for 4 weeks (20 mg/kg b.w.) remarkably attenuated the altered renal biomarkers by decreasing the levels of plasma creatinine, urea, and uric acid when compared to the Cisp-group. The nephroprotective capacity of MF was further strengthened by histopathological observations, where Cisp + MF treated rats showed lower number of inflammatory cells and tubular degenerative changes than the Cisp-group. The harmful effects of cisplatin on renal oxidative stress indicators (MDA, SOD, CAT, and GPx), were restored by the treatment of MF. In addition, the reduction of inflammatory markers (IL-6 and TNF-α), associated with alleviating DNA fragmentation, highlighted the preventive effect of MF in kidney tissue. Additionally, MF components presented lower binding energies when docked into the active site of TNF-α and IL-6. The present findings concluded that M. ferruginea extract exhibited nephroprotective potential, which may be attributed to its antioxidant and anti-inflammatory properties. Further work is recommended to confirm the current results, explore the involved mechanism of action, and determine the therapeutic doses and time.     

Synthesis,characterization and antimicrobial activities of copper complexes derived from 4-aminoantipyrine derivatives

Cu(II) complexes have been synthesized from the Schiff base ligands derived from furfurlyidene-4-aminoantipyrine and aniline (L¹)/p-nitroaniline (L²)/p-hydroxyaniline (L³). They were characterized using analytical and spectral techniques. All the Cu(II) complexes exhibit square planar geometry. The X-band ESR spectra of the copper complexes in DMSO solution at 300 and 77 K were recorded and their salient features are reported. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species, Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by serial dilution method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicate that the complexes exhibit higher antimicrobial activity than the Schiff base ligands. Superoxide dismutase and reducing power activities of the copper complexes have also been studied. Depending on the molecular structure, the [CuL²(OAc)₂] complex possess promising SOD mimetic activities.     

荧光自旋捕获探针的合成及ESR捕获研究

设计合成了具有荧光基团的新型硝酮类自由基捕获探针并对其结构进行了表征.自由基捕获实验结果表明,该探针能实现对超氧阴离子自由基与碳中心自由基的捕获.此外,该自由基捕获探针反应产物的荧光强度与被捕获自由基浓度之间存在相关性,有望建立依据荧光强度分析被捕获自由基浓度的新方法.     

Fabrication and Excellent Antibacterial Activity of Well-defined CuO/Graphdiyne Nanostructure

Copper oxide(CuO),due to its low cost,good chemical and physical stability,has recently been given special attention as a potential candidate for antibacterial agents.However,developing novel CuO nanocomposites with improved antibacterial property and unraveling the interface promotion mechanism has been a fundamental challenge for decades.Herein,well-defined CuO/graphdiyne(CuO/GDY)nanostructures with uniformly anchored CuO nanoparticles(ca.4.5 nm)have been fabricated.The CuO/GDY nanostructure exhibited superior E.coli inactivation efficiency,which is nearly 19 times and 7.9 times higher than the bare GDY and commercial CuO,respectively.The improved E.coli inactivation performance was mainly due to the increased reactive O2-species generated by the activation of molecular O2 over CuO/GDY surface.These findings demonstrate the efficient antibacterial activity of well-defined CuO/GDY nanostructures and provide insights on the development of efficient GDY-based antibacterial materials.     

A method for C(alpha) direct-detection in protonless NMR

Attempts are made to efficiently decouple (13)C nuclei without significant loss of coherence during the application of the decoupling package. Such attempts are based on the S(3)E spin-state selection method. A newly developed double S(3)E (DS(3)E) is particularly efficient for C(alpha) detection for proteins as large as 480 kDa.     

Chemiluminescence detection of superoxide anion release and superoxide dismutase activity: modulation effect of<Emphasis Type="Italic"> Pulsatilla chinensis</Emphasis>

A novel flow-injection chemiluminescence-based method has been developed for determination of superoxide dismutase (SOD) activity. An in-vitro superoxide anion generation xanthine/xanthine oxidase stable source was established on line with FIA/CL-detection apparatus, for measuring SOD activity. This method can detect SOD in the linear range of 0.002–2.00 U mL^–1 with a detection limit of 0.001 U mL^–1. Another method for detection of superoxide anion is based on the luminol–FeCl₃ chemiluminescence (CL) reaction. This method was used to evaluate superoxide release and SOD activity in rats treated with the traditional Chinese herb Pulsatilla chinensis, which resulted in high clearance of hepatitis B virus (HBV) after treatment of a hepatitis B patient. Interestingly, we found that treatment with Pulsatilla chinensis can specifically increase superoxide release by liver tissues and, at the same time, slightly increase extracellular SOD (ECSOD) activity in plasma; in particular it can markedly increase MnSOD activity in mitochondria in liver tissue. This work revealed a possible mechanism whereby Pulsatilla chinensis prevents possible infection (for example HBV) by specifically increasing superoxide release in the liver and increasing MnSOD activity to minimize superoxide-mediated toxicity.     

Development of a Xanthine Oxidase Modified Amperometric Electrode for the Determination of the Antioxidant Capacity

This paper describes the development of a xanthine oxidase/poly‐m‐phenylenediamine (XOD‐PPD)‐modified electrode. The biosensor was constructed by encapsulating XOD in a sol‐gel matrix deposited onto a platinum based screen‐printed electrode functionalized with a permselective PPD membrane. The hydrogen peroxide generated as a final product of the enzymatic reaction between the hypoxanthine and the XOD or by the spontaneous dismutation of superoxide radicals was selectively monitored at +700 mV. The use of a highly selective PPD layer blocked the nonspecific oxidation of other oxidizable molecules. Finally the biosensor was applied to the determination of the antioxidant capacity of acetylsalicylic acid.