Dados do Trabalho

Título

Meliponine geopropolis extracts induce oxidative stress in Leishmania amazonensis parasites

Introdução

Leishmania parasites have several mechanisms to maintain redox balance, ensuring their survival and successful establishment of host cell infection. Novel antileishmanial agents capable of disrupting parasite redox balance show promise as potential drug candidates. Meliponines’ geopropolis have been recognized for their pharmacological properties, including antiparasitic activity.

Objetivo (s)

This study aimed to evaluate the effect of geopropolis hydroethanolic extracts from Melipona mondury (MDRY), M. marginata (MRGT), M. quadrifasciata (MNDA and MBB), and M. bicolor (BCLR) on potential targets affecting the redox balance of L. amazonensis.

Material e Métodos

The extracts were subjected to spectrophotometric determination of total flavonoid (TFC) content using the flavonoid-aluminum complex formation method. In addition, the chemical profile was determined by UPLC-QTOF HRMS/MS and NMR. Axenic promastigote and amastigote forms were treated with the extracts (12.5-400 µg/mL) for 48 h, and viability was assessed by the resazurin assay. Mitochondrial dehydrogenases activity of treated parasites was evaluated by the MTT assay. Arginase inhibition was evaluated using the recombinant enzyme from Leishmania infantum as a model (LiARG). The reactive oxygen species (ROS) production was measured using the H2DCFDA fluorescent probe. Parasites’ autophagic activity was assessed through monodansylcadaverine staining assay.

Resultados e Conclusão

MRGT showed the highest amounts of flavonoids (344 mg QE/g). Fourteen substances, primarily flavonoids and diterpenes, were tentatively identified through UPLC-QTOF HRMS/MS analysis in all extracts. Chemometric analysis using NMR data indicated high chemical similarity between MBB and MDRY, and between BCRL and MRGT. MDRY was more effective against L. amazonensis promastigote and amastigote forms (IC50 = 154 and 19 µg/mL, respectively). Except for MRGT, all the extracts inhibited the mitochondrial dehydrogenase activity of treated parasites. In addition, MBB displayed the best result in LiARG inhibition (IC50 = 23 µg/mL), which is in line with the increased intracellular production of ROS by treated parasites. Furthermore, at 2xIC50 concentrations, MNDA, BCRL, MDRY, and MBB increased parasite autophagic activity after 12 h of exposure. These results indicate that geopropolis extracts are a source of substances with anti-L. amazonensis activity capable of inducing significant alterations that lead to oxidative stress and parasite death.

Palavras Chave

Geopropolis; leishmanicidal activity; oxidative stress.