Dioclea violacea lectin has potent in vitro leishmanicidal activity against Leishmania infantum via carbohydrate recognition domain

Despite promising advancements in leishmaniasis treatment, existing therapies often face limitations and significant side effects, stimulating the search for novel therapeutic alternatives. In this context, lectins, such as DVL extracted from Dioclea violacea seeds, have emerged as potential candidates due to their diverse biological activities. This study represents the first investigation of the leishmanicidal potential of DVL in vitro against Leishmania infantum. Our results demonstrate that DVL exhibits a leishmanicidal effect (IC₅₀/24 h = 49.37 μg/mL or 2 μM), binding to glycans on L. infantum. Fluorescence assays revealed that DVL can induce the production of reactive oxygen species (ROS) and cause damage to the parasite's membrane. DVL demonstrated a modulating effect when combined with amphotericin B and glucantime, enhancing the activity of these drugs by 40 % and 80 %, respectively. It also showed no cytotoxicity in Raw 264.7 cells and was able to override the toxic effect of amphotericin B on cells and reduce the survival rate of macrophages infected with amastigote forms, as well as their percentage of infection by 31 %. Therefore, DVL shows promise as a treatment for visceral leishmaniasis caused by L. infantum. Our findings provide valuable insights for future therapeutic development targeting leishmania glycans.