Antioxidant, antimicrobial and anticancer activity of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to investigate in vitro antioxidant, antimicrobial and anticancer activity of the acetone extracts of the lichens <it>Cladonia furcata, Lecanora atra </it>and <it>Lecanora muralis</it>.</p> <p>Methods</p> <p>Antioxidant activity was evaluated by five separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds and determination of total flavonoid content. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method against six species of bacteria and ten species of fungi. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method.</p> <p>Results</p> <p>Of the lichens tested, <it>Lecanora atra </it>had largest free radical scavenging activity (94.7% inhibition), which was greater than the standard antioxidants. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. Extract of <it>Cladonia furcata </it>was the most active antimicrobial agent with minimum inhibitory concentration values ranging from 0.78 to 25 mg/mL. All extracts were found to be strong anticancer activity toward both cell lines with IC₅₀values ranging from 8.51 to 40.22 μg/mL.</p> <p>Conclusions</p> <p>The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial and anticancer effects. That suggest that lichens may be used as as possible natural antioxidant, antimicrobial and anticancer agents to control various human, animal and plant diseases.</p

On-line experimental results of an argon gas cell-based laser ion source (KEK Isotope Separation System)

KEK Isotope Separation System (KISS) has been developed at RIKEN to produce neutron rich isotopes with N=126N=126 to study the ββ-decay properties for application to astrophysics. The KISS is an element-selective mass-separation system which consists of an argon gas cell-based on laser ion source for atomic number selection and an ISOL mass-separation system. The argon gas cell of KISS is a key component to stop and collect the unstable nuclei produced in a multi-nucleon transfer reaction, where the isotopes of interest will be selectively ionized using laser resonance ionization. We have performed off- and on-line experiments to study the basic properties of the gas cell as well as of the KISS. We successfully extracted the laser-ionized stable 56Fe (direct implantation of a 56Fe beam into the gas cell) atoms and 198Pt (emitted from the 198Pt target by elastic scattering with a 136Xe beam) atoms from the KISS during the commissioning on-line experiments. We furthermore extracted laser-ionized unstable 199Pt atoms and confirmed that the measured half-life was in good agreement with the reported value.status: publishe

Beta-decay spectroscopy of r-process nuclei around N=126

KEK Isotope Separation System (KISS) has been developed at RIKEN to study the β-decay properties of neutron-rich isotopes with neutron numbers around N = 126 to understand the astrophysical site of r-process. These nuclei will be produced by multi-nucleon transfer reactions in neutron-rich heavy ion collisions between 136Xe beam and 198Pt target. The KISS consists of an argon gas cell combined with a laser resonance ionization technique for atomic number selection, of an ISOL mass-separation system and of a detector system for the β-decay spectroscopy of nuclei around N = 126. The argon gas cell of KISS is a key component for thermalizing (stopping and neutralizing) and accumulating the unstable nuclei, and selectively ionizing them by using laser. We have performed off-and on-line experiments to study the basic properties of the gas cell as well as KISS. We successfully extracted the laser-ionized stable 198Pt atoms from the KISS at the commissioning on-line experiments. We furthermore extracted laser-ionized unstable 199Pt atoms and confirmed that the measured half-life was in good agreement with the reported value. Now KISS is ready for lifetime measurements of Pt, Ir, and Os isotopes around N = 126.status: publishe