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.

Keywords: Microhematocrit test; Trypanosoma cruzi; Capillary tube test; T. cruzi diagnostic methods

Fusarium equiseti strain FCHE and Fusarium oxysporum strain FCHJ were isolated from the roots of wilting habanero pepper (Capsicum chinense Jacq.) seedlings with root rot. Toward developing a biorational control of these serious phytopathogenic strains, ethanolic (EE) and aqueous (AE) extracts of different vegetative parts of 40 tropical native plants of the Yucatán Peninsula were screened for antifungal activity. Extracts of six out of 40 assayed plants were effective, and the most inhibitory extracts were studied further. EEs from Mosannona depressa (bark from stems and roots), Parathesis cubana (roots), and Piper neesianum (leaves) inhibited mycelial growth of both strains. Each active EE was then partitioned between hexane and acetonitrile. The acetonitrile fraction from M. depressa stem bark (MDT-b) had the lowest minimum inhibitory concentration of 1000 µg/mL against both pathogens and moderate inhibitory concentration (IC₅₀) of 462 against F. equiseti and 472 µg/mL against F. oxysporum. After 96 h treatment with EE from M. depressa stem bark, both strains had distorted hyphae and conidia and collapsed conidia in scanning electron micrographs. Liquid chromatography–ultraviolet–high resolution mass spectrometry analysis revealed that the major component of the fraction was α-asarone. Its antifungal effect was verified using a commercial standard, which had an IC₅₀ of 236 µg/mL against F. equiseti and >500 µg/mL against F. oxysporum. Furthermore, the P. cubana hexane fraction and P. neesianum acetonitrile fraction had antifungal activity against both Fusarium pathogens. These compounds provide new options for biorational products to control phytopathogenic fungi.