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  • articleNo Access

    Antioxidant Evaluation of Three Adaptogen Extracts

    Adaptogens are harmless herbs which have pharmaceutical benefits due to their balancing, regulative and tonic functions. However, despite these medicinal effects, the antioxidant potential of adaptogens is rarely mentioned. This study investigated the antioxidant potential of 3 adaptogen extracts, Rhodiola rosea (golden root), Eleutherococcus senticosis (Siberian ginseng) and Emblica officinalis (Indian gooseberry, Amla). The results of this study showed that R. rosea had the highest potential for singlet oxygen scavenging, hydrogen peroxide scavenging, ferric reducing, ferrous chelating and protein thiol protection than either of the other 2 extracts. E. senticosis, on the other hand, showed the best potential for hypochlorite scavenging. In addition, the polyphenol content in the 3 adaptogen extracts followed the order: R. rosea, E. officinalis and E. senticosis. Our data suggest that the antioxidant potential of the 3 adaptogen extracts was proportional to their respective polyphenol content. The supplementation of adaptogen extracts containing high levels of polyphenols may not only have adaptogen properties, but may decrease the risk of complications induced by oxidative stress.

  • articleNo Access

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    • articleNo Access

      Metalloporphyrin/G-quadruplexes: From basic properties to practical applications

      Guanine-rich single-stranded nucleic acids self-assemble into G-quadruplex nanostructures (predominately in the presence of K+-ions). Metalloporphyrins bind to the G-quadruplex nanostructures to form supramolecular assemblies exhibiting unique catalytic, electrocatalytic and photophysical properties. This paper addresses the advances in the characterization and the implementation of the metalloporphyrin/G-quadruplexes complexes for various applications. Out of the different complexes, the most extensively studied complexes are the hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme and the Zn(II)-protoporphyrin IX-functionalized G-quadruplex. Specifically, the hemin/G-quadruplex was found to act as a catalyst for driving different chemical transformations that mimic the native horseradish peroxidase enzyme, and, also, to function as an electrocatalyst for the reduction of H2O2. Also, the hemin/G-quadruplex stimulates interesting photophysical and photocatalytic processes such as the electron-transfer quenching of semiconductor quantum dots or the chemiluminescence resonance energy transfer to semiconductor quantum dots. Alternatively, Zn(II)-protoporphyrin IX associated with G-quadruplexes exhibit intensified fluorescence properties. Beyond the straight forward application of the metalloporphyrin/G-quadruplexes as catalysts that stimulate different chemical transformations, the specific catalytic, electrocatalytic and photocatalytic functions of hemin/G-quadruplexes are heavily implemented to develop sophisticated colorimetric, electrochemical, and optical sensing platforms. Also, the unique fluorescence properties of Zn(II)-protoporphyrin IX-functionalized G-quadruplexes are applied to develop fluorescence sensing platforms. The article exemplifies different sensing assays for analyzing DNA, ligand-aptamer complexes and telomerase activity using the metalloporphyrins/G-quadruplexes as transducing labels. Also, the use of the hemin/G-quadruplex as a probe to follow the operations of DNA machines is discussed.

    • articleFree Access

      A NEW QUANTITATIVE DETECTION METHOD OF RECOMBINANT CFP10-ESAT6 AMALGAMATION PROTEINS FROM MYCOBACTERIUM TUBERCULOSIS BASED ON MICRO-MAGNETIC PROBES STRATEGY

      A new rapid, specific and sensitive method for assay of recombinant CFP10-ESAT6 amalgamation proteins from Mycobacterium tuberculosis was proposed. The method used streptavidin-coated magnetic beads to enrich the specific biotinylated anti-CFP10 antibody, then adopted a sandwich-type enzyme linked immunosorbent assay technology with two kinds of monoclonal antibodies: biotinylated anti-CFP10 antibody and HRP-labeled anti-CFP10 antibody to identify the target CFP10-ESAT6 proteins, and finally detected chemiluminescence intensity by a small home-made optical sensor. It was shown that, the corresponding chemiluminescence intensity had a good logarithmic linear response to the concentration of CFP10-ESAT6 proteins when ranging at 1 ~ 1000 ng/mL, and the correlation coefficient is 0.9937. The proposed method could detect the CFP10-ESAT6 proteins with low detection limit (1 ng/mL) and the detection time could be controlled within 45 min. Compared with commonly used detection methods of M. tuberculosis, this method was easy to operate, faster, and of higher sensitivity. The achievement of the quantitative detection of CFP10-ESAT6 proteins has important scientific significance and wide application prospects in tuberculosis control.

    • articleOpen Access

      A flow chemiluminescence paper-based microfluidic device for detection of chromium (III) in water

      In this work, a solely gravity and capillary force-driven flow chemiluminescence (GCF-CL) paper-based microfluidic device has been proved for the first time as a new platform for inexpensive, usable, minimally-instrumented dynamic chemiluminescence (CL) detection of chromium (III) [Cr(III)], where an appropriate angle of inclination between the loading and detection zones on the paper produces a rapid flow of CL prompt solution through the paper channel. For this study, we use a cost-effective paper device that is manufactured by a simple wax screen-printing method, while the signal generated from the Cr(III)-catalyzed oxidation of luminol by H2O2 is recorded by a low-cost and luggable CCD camera. A series of GCF-CL affecting factors have been evaluated carefully. At optimal conditions, two linear relationships between GCF-CL intensities and the logarithms of Cr(III) concentrations are obtained in the concentration ranges of 0.025–35mg/L and 50–500mg/L separately, with the detection limit of 0.0245mg/L for a less than 30s assay, and relative standard deviations (RSDs) of 3.8%, 4.5% and 2.3% for 0.75, 5 and 50mg/L of Cr(III) (n=8). The above results indicate that the GCF-CL paper-based microfluidic device possesses a receivable sensitivity, dynamic range, storage stability and reproducibility. Finally, the developed GCF-CL is utilized for Cr(III) detection in real water samples.

    • articleOpen Access

      SYNTHESIS AND CHARACTERIZATION OF LUMINOL PERSULPHATE CHEMILUMINESCENCE IN AQUEOUS AMINES

      The chemiluminescence (CL) emission spectra of luminol were recorded using Fuss spectrograph in different aqueous aliphatic amines using sodium persulphate alone and mixture with hydrogen peroxide as an oxidant. The CL emission spectra after resolution showed two emission bands at 425 and 455 nm. The CL mechanism was explained on the basis of two exited state species formed during oxidation of luminol. The CL of luminol is found to be very weak as persulphate slowly produced oxygen. The glow become intense with time as more and more oxygen is made available for oxidation of luminol. The mixture of hydrogen peroxide and sodium persulphate is found to be more effective in producing intense and long lived CL glow for luminol. The CL emission band of luminol by using sodium persulphate and mixture with hydrogen peroxide is explained on the basis of formation of exited singlet and triplet state of 3-aminophthalate ion (3-APA). The shorter wavelength emission band of 425 nm is found to be very weak in intensity as compared to longer wavelength emission band of 455 nm. Thus phosphoresce is favored in case of persulphate CL of luminol.