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A total of 82 fungal extracts were selected and screened against Mycobacterium tuberculosis and promastigotes of Leishmania mexicana strains. Results showed inhibitory activity in 29 % of the fungal strains against at least one of the targets tested. The most significant antituberculosis (antiTB) effects were presented by Cylindrocarpon sp. XH9B, Fusarium sp. TA54, Fusarium XH1Ga, Gliocladium penicillioides TH04 and TH21, Gliocladium sp. TH16, Kutilakesa sp. MR46, and Verticillium sp. TH28 strains (minimal inhibition concentration (MIC) = 1.56-25 μg/ml). Mortality of L. mexicana promastigotes was displayed by only four strains, Fusarium sp. TA50, Fusarium sp. TA54, Verticillium sp. TH28, and the unidentified 2TA2 strain (IC(50) = 14.23-100 μg/ml and IC(100) = 50-100 μg/ml). Seven of these most active strains were defatted and their corresponding fractions evaluated again. The results showed the best antiTB activity in Gliocladium sp. TH16 (MIC = 1.56 μg/ml) and the highest leishmanicidal potential in Fusarium sp. TA54 (IC(50) = 6.36 μg/ml). These results show that fungi living in the tropical regions of México have the ability to produce bioactive metabolites that could be used in the near future as natural products to control neglected tropical diseases.

Betulinic acid (1), isolated from the crude extract of the leaves of Pentalinon andrieuxii (Apocynaceae), together with betulinic acid acetate (2), betulonic acid (3), betulinic acid methyl ester (4), and betulin (5) were evaluated for their antiprotozoal activity. The results showed that modifying the C-3 position increases leishmanicidal activity while modification of the C-3 and C-28 positions decreases trypanocidal activity., (Copyright 2009 Elsevier GmbH. All rights reserved.)

Aqueous and organic extracts of twenty-seven species of marine algae (14 species of Rhodophyta, 5 species of Phaeophyta and 8 species of Chlorophyta) collected from the Gulf of Mexico and Caribbean coast of the Yucatan Peninsula (Mexico) were evaluated for their antileishmanial in vitro activity against Leishmania mexicana promastigote forms. The cytotoxicity of these extracts was also assessed using brine shrimp. Organic extracts from Laurencia microcladia (Rhodophyta), Dictyota caribaea, Turbinaria turbinata and Lobophora variegata (Phaeophyta) possessed promising in vitro activity against L. mexicana promastigotes (LC(50) values ranging from 10.9 to 49.9 microg/ml). No toxicity of algal extracts against Artemia salina was observed with LC50 ranging from 119 to >or=1000 microg/ml. Further studies on bio-guided fractionation, isolation and characterization of pure compounds from these species as well as in vivo experiments are needed and are already in progress.