Biostimulated-sesame sprout extracts as potential agents against Leishmania mexicana.

Leishmania mexicana is one of the causal agents of cutaneous leishmaniasis. Current antileishmanial chemotherapeutics have demonstrated adverse side effects; thus, alternative treatments are needed. In this study, we performed in silico and in vitro analyses of the leishmanicidal potential of the most abundant phenolic compounds identified in black sesame sprouts biostimulated with Bacillus clausii. The molecular docking analysis showed strong interactions (binding free energies between -6.5 and -9.5 kcal/mol) of sesaminol 2-O-triglucoside, pinoresinol dihexoside, isoverbascoside, and apigenin with the arginase, leishmanolysin, cysteine peptidase B, and pyruvate kinase leishmanial enzymes. Furthermore, almost all phenolic compounds interacted with the active site residues of L. mexicana enzymes. In vitro, the B. clausii-biostimulated sprout phenolic extracts and apigenin inhibited the growth of promastigotes with IC50 values of 0.08 mg gallic acid equivalent/mL and 6.42 µM (0.0017 mg/mL), respectively. Additionally, in the macrophage infection model, cells treated with B. clausii-biostimulated sprout phenolic extracts and infected with L. mexicana exhibited significantly (P < 0.05) reduced nitric oxide production and decreased parasite burden. Altogether, our study provides important data related to high efficacy and less toxic natural antileishmanial candidates against promastigotes of L. mexicana.

Cloning and Recombinant Expression of Elongation Factor-1α of Leishmania mexicana.

Leishmania mexicana is an intracellular parasite that causes cutaneous leishmaniasis (CL) in some countries, including Mexico. Recently, we identified the elongation factor-1α (EF-1α) of L. mexicana by immunoproteomic analysis. In Leishmania donovani, this molecule has been reported as a virulence factor involved in downregulation of macrophages by no-canonical function when EF-1α interacts with protein tyrosine phosphatase-1 (SHP-1). However, in L. mexicana the key role of EF-1α in host-parasite relationship has not been elucidated, by this reason we started with cloning and recombinant expression of this antigen. A sequence of 1350 bp corresponding to EF-1α (EF-Lm) full-length gene was amplified from genomic DNA of L. mexicana (GenBank: MG256973); this gene contains only one nucleotide change: C464T, compared with L. mexicana reference sequence (GenBank: FR799570.1). The gene cloned (EF-Lm) codes for a protein of 449 residues. It was expressed in Escherichia coli and purified as 63 kDa sumo-fusion protein, which was recognized in the sera of patients diagnosed with CL. Our results show that EF-Lm is immunogenic during infection, and the rEF-Lm could be used for further analyses in the host-parasite relationship.