title: Antiprotozoal, antitubercular and cytotoxic potential of cyanobacterial (blue-green algal) extracts from Ireland.
abstract: Cyanobacteria (= blue-green algae) are prolific producers of structurally distinct and biologically active metabolites. In the continuation of our search for new sources of anti-infective natural products, we have assessed the in vitro antiprotozoal (Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani) and antitubercular (Mycobacterium tuberculosis) potential of samples of two terrestrial cyanobacteria, Nostoc commune (collected when desiccated and wet) and Rivularia biasolettiana. The cytotoxic potential of the extracts was also evaluated against primary L6 cells. Except for T. cruzi and M. tuberculosis, the crude extracts were active against all the organisms tested and showed no toxicity. The crude extracts were then partitioned between n-hexane, chloroform and aqueous methanol and retested against the same panel of pathogens. The chloroform sub-extracts of both N. commune samples showed significant activity against T. b. rhodesiense (IC50 values 2.0 and 3.5 microg/mL) and P. falciparum (IC50s 7.4 and 5.8 microg/mL), with low toxicity. This trend was also true for R. biasolettiana extracts, and its chloroform sub-extract showed notable activity against all parasitic protozoa. There were differences in the biological activity profiles of extracts derived from desiccated and hydrated forms of N. commune. To our knowledge, this is the first study assessing the anti-infective activity of desiccated and hydrated forms of N. commune, as well as R. biasolettiana. Furthermore, the present work reports such biological activity in terrestrial cyanobacteria from Ireland for the first time. These results warrant the further study of Irish terrestrial cyanobacteria as a valuable source of new natural product leads for the treatment of parasitic protozoal infections.
authors: Department of Pharmaceutical and Biological Chemistry, Centre for Pharmacognosy and Phytotherapy, School of Pharmacy, University of London, London WC1N 1AX, UK.
authors: Barbara
authors: B
authors: Broniatowska
authors: Andrea
authors: A
authors: Allmendinger
authors: Marcel
authors: M
authors: Kaiser
authors: Damien
authors: D
authors: Montamat-Sicotte
authors: Suzie
authors: S
authors: Hingley-Wilson
authors: Ajit
authors: A
authors: Lalvani
authors: Michael
authors: M
authors: Guiry
authors: Gerald
authors: G
authors: Blunden
authors: Deniz
authors: D
authors: Tasdemir