Does usnic acid affect microtubules in human cancer cells?

Department of Surgery and Molecular Oncology, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, UK.
Brazilian journal of biology = Revista brasleira de biologia (Impact Factor: 0.68). 04/2010; 70(3):659-64. DOI: 10.1590/S1519-69842010005000013
Source: PubMed

ABSTRACT Usnic acid, a lichen metabolite, is known to exert antimitotic and antiproliferative activities against normal and malignant human cells. Many chemotherapy agents exert their activities by blocking cell cycle progression, inducing cell death through apoptosis. Microtubules, protein structure involved in the segregation of chromosomes during mitosis, serve as chemotherapeutical targets due to their key role in cellular division as well as apoptosis. The aim of this work was to investigate whether usnic acid affects the formation and/or stabilisation of microtubules by visualising microtubules and determining mitotic indices after treatment. The breast cancer cell line MCF7 and the lung cancer cell line H1299 were treated with usnic acid 29 microM for 24 hours and two positive controls: vincristine (which prevents the formation of microtubules) or taxol (which stabilizes microtubules). Treatment of MCF7 and H1299 cells with usnic acid did not result in any morphological changes in microtubules or increase in the mitotic index. These results suggest that the antineoplastic activity of usnic acid is not related to alterations in the formation and/or stabilisation of microtubules.

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    ABSTRACT: A rapid and sensitive method for determining usnic acid of Lethariella cladonioides in rat was established using high performance liquid chromatography (HPLC) quadrupole time-of-flight (QTOF) tandem mass (MS/MS). Rat plasma was pretreated by mixture of acetonitrile and chloroform to precipitate plasma proteins. Chromatographic separation was achieved on a column (50 × 2.1 mm, 5 μm) with a mobile phase consisting of water (containing 5 × 10−3 M ammonium formate, pH was adjusted to 3.0 with formic acid) and acetonitrile (20:80, v/v) at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via collision induced dissociation (CID) under negative ionization mode. The MS/MS transitions monitored were m/z 343.0448 → m/z 313.2017 for usnic acid and m/z 153.1024 → m/z 136.2136 for protocatechuic acid (internal standard). The linear range was calculated to be 2.0-160.0 ng/mL with a detection limit of 3.0 pg/mL. The inter- and intra-day accuracy and precision were within ± 7.0%. Pharmacokinetic study showed that the apartment of usnic acid in vivo confirmed to be a two compartment open model. The method was fully valid and will probably be an alternative for pharmacokinetic study of usnic acid.
    Bulletin- Korean Chemical Society 03/2013; 34(6):1684-1688. DOI:10.5012/bkcs.2013.34.6.1684 · 0.84 Impact Factor
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    ABSTRACT: Since its first isolation in 1844, usnic acid [2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione] has become the most extensively studied lichen metabolite and one of the few that are commercially available. Lichens belonging to usnic acid-containing genera have been used as crude drugs throughout the world. There are indications of usnic acid being a potentially interesting candidate for such activities as anti-inflammatory, analgesic, healing, antioxidant, antimicrobial, antiprotozoal, antiviral, larvicidal and UV protection. However, some studies reported the liver toxicity and contact allergy. Thus, further studies are needed to establish the efficacy and safety of usnic acid.
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    ABSTRACT: Novel multifunctional hydroxyphenylimino ligands (L1, L2 and L3) were synthesized by the condensation of 2-aminophenol, 3-aminophenol and 4-aminophenol with usnic acid, a lichen metabolite. The synthesized ligands and their Cu(ii), Co(ii), Ni(ii) and Mn(ii) complexes were characterized using FT-IR, UV-Vis, (1)H-NMR, (13)C-NMR, 1D- and 2D NMR (DEPT, COSY, HMQC and HMBC), LC-MS and TGA. In addition, the metal complexes of the novel ligands were prepared with high yields using Cu(ii), Co(ii), Ni(ii) and Mn(ii) salts and were characterized using the FT-MIR/FAR, UV-Vis, elemental analysis, ICP-OES and TG/DTA techniques. The ligands and their complexes were tested against ten important pathogen microorganisms using the disc diffusion method and the metal complexes of the ligands were more active against all of the microorganisms tested with a broad spectrum than the ligands exhibiting 11-32 mm inhibition zones. On the other hand, a broad spectrum of the strongest antimicrobial activity was determined for the Mn(ii) and Cu(ii) complexes of the hydroxyphenylimino ligand with usnic acid (L3). In addition, the antimutagenic activities of all of the ligands and their metal complexes were determined using the Ames-Salmonella and E. coli WP2 microbial assay systems and they showed varied and strong antimutagenic effects. In general, it has been found that the Co and Mn complexes of the ligands possess potent antimutagenic activity. In view of these results, it can be concluded that some metal complexes can be used as antimicrobial and anticancer agents.
    Dalton Transactions 03/2014; 43(16). DOI:10.1039/c3dt53624f · 4.10 Impact Factor

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