A superoxide dismutase excreted by promastigote forms of L. (Viannia) peruviana (SODe-Lp), L. (Viannia) brazilensis (SODe-Lb), and L. (L.) amazonensis (SODe-La) is tested to evaluate its potential value as a diagnostic tool of mucocutaneous and Andean cutaneous leishmaniasis. We used 45 sera with mucocutaneous leishmaniasis (SL) and 68 with Andean cutaneous leishmaniasis (ACL). SODe-Lp antigen was recognized by 94% of the serum from ACL patients, and the SODe-Lb antigen was recognized by 93% of the serum from SL patients. Meanwhile, the result for SL and ACL patients with SODe-La antigen was 69% and 43% and SODe-Li was 11% and 9%, respectively. This suggest that antibodies to SODe-Lp undergo further response in patients with ACL and the antibodies to SODe-Lb do so preferentially in patients with SL. The SODe ELISA may be useful in endemic areas for discriminative assays between patients with different forms of leishmaniases and those with other clinical conditions.

Four superoxide dismutase (SOD) activities (SOD I, II, III, and IV)

An excreted iron superoxide dismutase of pI 3.75 and a molecular mass of approximately 25 kDa was partially purified by QAE Sephadex ion-exchange chromatography from the in vitro culture of Leishmania (Leishmania) infantum. This enzyme was detected by enzyme-linked immunosorbent assay and Western blot of anti-L. infantum antibodies in dog serum. For the determination of the sensitivity and specificity of this protein, the results using the complete-parasite antigen fraction were taken as references. For this, 39 sera were assayed in dogs from different Spanish provinces. By Western blot, at a dilution of 1:250, 82% of the sera were positive when superoxide dismutase excreted was used as the antigen, against 56.4% positivity when the complete parasite was used as the antigen. These findings support the results of a previous study, indicating that the superoxide dismutase excreted can be useful in diagnosing L. (L.) infantum.

No abstract

The use of natural products for the treatment of protozoal infections (Leishmania and Trypanosoma spp.) is well known and has been documented since ancient times. We have already established an in vitro culture system using mammalian host cells (Vero) infected with Trypanosoma cruzi in which the time course of parasite growth is determined quantitatively. This system was used to screen anti-T. cruzi agents using two experimental models: simultaneous cell infection and compound addition or preincubation of the parasite with the test compound prior to cell infection. Among 64 diterpenoid alkaloids tested, including C₁₉ and C₂₀ skeletons, five C₂₀ compounds were active on T. cruzi epimastigotes: azitine, isoazitine and 15,22-O-diacetyl-19-oxodihydroatisine had moderate effects on the parasite, while atisinium chloride and 13-oxocardiopetamine were potent T. cruzi epimastigote growth inhibitors with activity levels similar to that of benznidazole, used as the reference drug. Additionally, these compounds decreased the ability of metacyclic forms to invade mammalian cells, their intracellular replications and their transformation into trypomastigotes, with no toxicity to the host cell. These results suggest that these alkaloids are structural leads of clinically active compounds against T. cruzi and probably other members of the Trypanosomatidae.