Author: MIGUEL ENRIQUE ROSADO VALLADO
We tested a mixture of Tridax procumbens, known for its direct action against Leishmania mexicana, and Allium sativum, known for its immunomodulatory effect, as an alternative to treat cutaneous leishmaniasis. Acute oral toxicity was tested with the Up-and-Down Procedure (UDP) using a group of healthy mice administered with either T. procumbens or A. sativum extracts and compared with a control group. Liver injury and other parameters of toxicity were determined in mice at day 14. The in vivo assay was performed with mice infected with L. mexicana promastigotes and treated with either a mixture of T. procumbens and A. sativum or each extract separately. The thickness of the mice's footpads was measured weekly. After the 12-week period of infection, blood samples were obtained by cardiac puncture to determine the total IgG, IgG1 and IgG2a immunoglobulins by a noncommercial indirect ELISA. We showed that the mixture of T. procumbens and A. sativum extracts was better at controlling L. mexicana infection while not being toxic when tested in the acute oral toxicity assay in mice. An increase in the ratio of IgG2a/IgG1 indicated a tendency to raise a Th1-type immune response in mice treated with the mixture. The mixture of T. procumbens and A. sativum extracts is a promising natural treatment for cutaneous leishmaniasis and its healing effects make it a good candidate for a possible new phytomedicine.
Martín Antonio Pablo Moreno Pérez MARIA MARCELA GAMBOA ANGULO GABRIELA PATRICIA HEREDIA ABARCA Blondy Beatriz Canto Canché MIGUEL ENRIQUE ROSADO VALLADO Irma Leticia Medina Baizabal RAUL TAPIA TUSSELL (2014)
In the search for natural alternatives to control fungal diseases, antagonistic fungi are valuable sources to find new models. In the present study, a total of 41 tropical micromycetes were isolated from plant debris submerged in sinkholes of the Yucatán Península. All strains were tested in antagonist assays against four phytopathogenic fungi (Colletotrichum gloeosporioides, Corynespora cassiicola, Curvularia sp. and Fusarium sp.). Results of the antagonistic assays showed mycelial growth inhibition (MCI ≥50 %) by 17 isolates (41 %) against at least one of the targets tested. The highest inhibition was exhibited by the Hypocrea lixii OSN-37 (MCI=61-77%) and Rhizoctonia solani OSE-73 (MCI=55-64%) strains against all targets while Pestalotiopsis mangiferae OH-02 (51-59%) caused inhibition on three of four pathogen strains. These three strains were cultured in fermented rice to obtain their ethyl acetate and methanol extracts which were tested against C. gloeosporioides using the microdilution assay. Results showed H. lixii OSN-37 and R. solani OSE-73 to be producers of antifungal metabolites as one of their modes of action. In conclusion, three promising antagonistic native strains were isolated from plant debris submerged in the Yucatán sinkholes, representing a valuable contribution to the development of ecofriendly alternatives to control fungal diseases in agriculture crops of the tropical regions.