Broniatowska Barbara, Allmendinger Andrea, Kaiser Marcel, Montamat-Sicotte Damien, Hingley-Wilson Suzie, Lalvani Ajit, Guiry Michael, Blunden Gerald, Tasdemir Deniz
Department of Pharmaceutical and Biological Chemistry, Centre for Pharmacognosy and Phytotherapy, School of Pharmacy, University of London, London WC1N 1AX, UK.
Nat Prod Commun. 2011 May;6(5):689-94.
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.
蓝细菌（=蓝藻）能大量产生结构独特且具有生物活性的代谢产物。在我们持续寻找抗感染天然产物新来源的过程中，我们评估了两种陆生蓝细菌——普通念珠藻（分别在干燥和湿润状态下采集）和偏肿念珠藻样品的体外抗原生动物（恶性疟原虫、布氏罗得西亚锥虫、克氏锥虫、杜氏利什曼原虫）及抗结核（结核分枝杆菌）潜力。还评估了提取物对原代L6细胞的细胞毒性潜力。除克氏锥虫和结核分枝杆菌外，粗提物对所有测试生物均有活性且无毒性。然后将粗提物用正己烷、氯仿和甲醇水溶液进行分配，并针对同一组病原体重新进行测试。普通念珠藻两个样品的氯仿亚提取物对布氏罗得西亚锥虫（IC50值分别为2.0和3.5微克/毫升）和恶性疟原虫（IC50分别为7.4和5.8微克/毫升）显示出显著活性，且毒性较低。偏肿念珠藻提取物也呈现这种趋势，其氯仿亚提取物对所有寄生原生动物均显示出显著活性。普通念珠藻干燥和水合形式的提取物在生物活性谱方面存在差异。据我们所知，这是第一项评估普通念珠藻干燥和水合形式以及偏肿念珠藻抗感染活性的研究。此外，本研究首次报道了爱尔兰陆生蓝细菌的这种生物活性。这些结果表明有必要进一步研究爱尔兰陆生蓝细菌，将其作为治疗寄生原生动物感染的新型天然产物先导物的宝贵来源。
