Proliferative effect of Dracontium spruceanum on Leishmania

Introduction: Leishmaniasis, transmitted by sandflies and caused by protozoa of the genus Leishmania, primarily presents in its cutaneous form. Difficulties in diagnosis and the adverse effects of conventional treatments have driven the search for alternatives, such as Dracontium spruceanum ("sacha jergón"), an Amazonian plant containing compounds with potential activity against Leishmania spp., whose efficacy still requires scientific validation. Objective: To determine the effect of the aqueous extract of Dracontium spruceanum against Leishmania. Methods: Detection of Leishmania (Viannia) spp. kDNA was performed by PCR using primers MP1-L and MP3-H, with LTB-300 (L. (V.) braziliensis) and DNAfree water as controls. Promastigotes were isolated from cutaneous lesion scrapings and cultured in biphasic medium, achieving differentiation into axenic amastigotes in Schneider medium, with pH 4.7 as the optimal condition for complete conversion. Plant material of Dracontium spruceanum collected in Ucayali (Peru) was processed to obtain an aqueous extract (100 mg/mL). The antiparasitic activity of the extract was evaluated by the MTT assay against promastigotes and amastigotes, using Glucantime as a positive control. Data obtained were analyzed by ANOVA, considering p-values < 0.05 as significant. Results: In in vitro assays with Leishmania sp., administration of Glucantime (25 mg/mL) produced a significant decrease in cell viability of promastigotes (71%) and axenic amastigotes (38%) compared to the control group. Conversely, the aqueous extract of Dracontium spruceanum (8.33 mg/mL) caused a significant increase in promastigote (160%) and amastigote (179%) viability, indicating a stimulatory effect on parasite growth (p < 0.05). Discussion and conclusion: The in vitro effect of the aqueous extract of Dracontium spruceanum on promastigotes and axenic amastigotes of Leishmania sp. was investigated. Unlike Glucantime, which significantly decreased parasite viability, the extract consistently promoted proliferation in both forms. This result, uncommon in medicinal plant studies, could be linked to the presence of ceramides and cerebrosides, compounds in the genus Dracontium previously associated with mitogenic activity. Additional dose-response studies and phytochemical analysis are needed to identify the active compounds and clarify their mechanism of action.