Isoenzyme characterization of Leishmania infantum toward checking the antioxidant activity of superoxide dismutase and glutathione peroxidase.

Background: Leishmania infantum is the major causative agent of visceral leishmaniasis in Mediterranean regions. Isoenzyme electrophoresis (IE), as a biochemical technique, is applied in the characterization of Leishmania species. The current study attempted to investigate the isoenzyme patterns of logarithmic and stationary promastigotes and axenic amastigotes (amastigote-like) of L. infantum using IE. The antioxidant activity of superoxide dismutase (SOD) and glutathione peroxidase (GPX) was also checked in the aforementioned forms. Method: After L. infantum cultivation and obtaining logarithmic and stationary promastigotes, axenic amastigotes were achieved by incubation of stationary promastigotes at 37 °C for 48 h. The lysate samples were prepared and examined for six enzymatic systems including glucose-6-phosphate dehydrogenase (G6PD), nucleoside hydrolase 1 (NH1), malate dehydrogenase (MDH), glucose-phosphate isomerase (GPI), malic enzyme (ME), and phosphoglucomutase (PGM). Additionally, the antioxidant activity of SOD and GPX was measured. Results: GPI, MDH, NH1, and G6PD enzymatic systems represented different patterns in logarithmic and stationary promastigotes and axenic amastigotes of L. infantum. PGM and ME showed similar patterns in the aforementioned forms of parasite. The highest level of SOD activity was determined in the axenic amastigote form and GPX activity was not detected in different forms of L. infantum. Conclusion: The characterization of leishmanial-isoenzyme patterns and the measurement of antioxidant activity of crucial antioxidant enzymes, including SOD and GPX, might reveal more information in the biology, pathogenicity, and metabolic pathways of Leishmania parasites and consequently drive to designing novel therapeutic strategies in leishmaniasis treatment. [ABSTRACT FROM AUTHOR]