The treatment of leishmaniasis has limitations due to drug toxicity and the increasing resistance of the parasite. In this study, we analyze the role of oxidative stress in the pathogenesis and treatment of leishmaniasis, as well as in new therapeutic alternatives of natural origin. The evasion mechanisms against the host immune response involve surface molecules present in the parasite, which modulate oxidative stress to ensure its survival. Drug treatment requires strict monitoring to minimize adverse reactions and ensure patient safety, as mechanisms such as lipid peroxidation, mitochondrial dysfunction, and depletion of antioxidant defenses are associated with drug toxicity. Plant-derived products with antileishmanial activity impact the parasite’s redox balance, inducing apoptosis and reducing its parasitic load. Most studies are still in preliminary stages, making in vivo assays and clinical studies essential, along with the development of accessible formulations. Oxidative stress is involved in the pathogenesis of leishmaniasis, as Leishmania manipulates the host’s redox balance to survive. It also contributes to drug toxicity, as antimonials and amphotericin B increase reactive oxygen species, causing cellular damage. Several plant-derived compounds have demonstrated antileishmanial activity by modulating oxidative stress and promoting parasite apoptosis. Examples include alkaloids from Aspidosperma nitidum, lignans from Virola surinamensis, flavonoids from Geissospermum vellosii, and triterpenoids such as β-sitosterol. Although these compounds show promising selectivity, most studies remain in preliminary stages, requiring in vivo assays and clinical studies to confirm efficacy and safety, as well as the development of affordable formulations.

Teucrium polium L. is a plant with various claims of ethnobotanical use, primarily for inflammatory diseases. Chemical studies have already isolated different types of terpenes from the species, and studies have established its pharmacological potential. The present study evaluates the components of T. polium essential oil cultivated in the Algerian Saharan Atlas. GC-MS identified the major components as fenchone (31.25%), 3-carene (15.77%), cis-limonene oxide (9.77%), and myrcene (9.15%). In the in silico prediction, molecules with more than 1% abundance were selected. Regarding Lipinski’s rule, all molecules followed the rule. All molecules were found to be toxic in at least one model, with some molecules being non-genotoxic (6, 8, 10, 11, 12, 13) and others being non-mutagenic (5, 7, 9, 14). Three molecules were selected that showed the best results in pharmacokinetic and toxicity studies: the molecules that did not present carcinogenic potential (7—myrtenal; 9—myrtenol; 14—verbenol). The molecular target was established, and it seems that all three bound to the nuclear factor NF-kappa-B. Based on the docking and molecular dynamics results, these molecules have potential as anti-inflammatory and antitumor therapies, with further in vitro and in vivo studies needed to evaluate their activity and toxicity.

Objetivo: o presente estudo realizou uma revisão integrativa visando avaliar os aspectos químicos de espécies pertencentes ao gênero Costus, bem como de estudos que avaliaram as atividades biológicas. Metodologia: Inicial levantamento bibliográfico em PUBMED e SCOPUS, utilizando strings “Costus AND medicine pharmacological”. Foram lidos títulos e resumos, sendo selecionados de acordo com critérios de elegibilidade. Na segunda etapa, realizou-se a leitura dos artigos na integras e excluídos os artigos que não estiveram de acordo com critérios de inclusão. Resultados: Foram incluídos 21 artigos, tendo relação com informações fitoquímicas e diferentes atividades biológicas. Espécies do gênero Costus demonstraram atividades promissoras para o tratamento da inflamação, dor, diabetes e nefrolitíase, tendo relação com algumas alegações de uso popular. Considerações finais: Em síntese, espécies pertencentes ao gênero Costus são promissoras em termos medicinais, sendo necessários outros ensaios que avaliem a segurança dos compostos presentem nas espécies do gênero para futuros ensaios clínicos.

Leishmaniasis is a neglected tropical disease that remains a major public health problem in many endemic regions. Current treatments are limited by toxicity, high cost, and emerging drug resistance. Plant-derived compounds have been investigated as potential therapeutic alternatives due to their antiparasitic and immunomodulatory properties. This systematic review aimed to evaluate the therapeutic potential and immunomodulatory effects of plant-derived compounds in experimental models of leishmaniasis. A systematic search was conducted in PubMed, Scopus, and Web of Science databases for studies published between January 2014 and December 2024. The search strategy included terms related to Leishmania, medicinal plants, natural products, and experimental models. Eligible studies were in vivo experimental investigations evaluating plant extracts, fractions, or isolated compounds in animal models of leishmaniasis. Study selection followed the PRISMA 2020 guidelines. Data were extracted regarding experimental models, phytochemical composition, antiparasitic outcomes, and immunological responses. Ten studies met the inclusion criteria. Most studies were conducted in BALB/c mice infected with Leishmania donovani or Leishmania (Leishmania) amazonensis. Plant-derived treatments included crude extracts, purified fractions, and isolated compounds such as lupeol and plant-derived protease inhibitors. The evaluated treatments demonstrated significant reductions in parasite load in liver, spleen, or lesion sites. Immunological analyses consistently showed a shift toward a protective Th1-type immune response, characterized by increased production of IFN-γ, IL-12, nitric oxide (NO), and reactive oxygen species (ROS), along with decreased levels of IL-10 and TGF-β. Several studies also reported improvements in histopathological parameters and low toxicity. Plant-derived compounds demonstrate promising antiparasitic and immunomodulatory effects in experimental models of leishmaniasis. These findings support the potential of natural products as alternative or complementary therapeutic strategies for leishmaniasis. However, further standardized experimental studies and clinical investigations are necessary to validate their safety and efficacy.

Eleutherine plicata is used in the Amazon region for the treatment of amoebiasis. The plant has been found to contain naphthoquinones (eleutherin and isoeleutherin) and naphthalene derivatives (eleutherol and isoeleutherol), which have been isolated. This study investigated, through molecular docking, the potential of isoeleutherin, eleutherin, eleutherol, and isoeleutherol against different proteins of Entamoeba histolytica. The potential amoebicidal effects were assessed by examining the interaction with two proteins, O-acetyl-serine sulfhydrylase (3BM5) and thioredoxin reductase (4CCQ), obtained from the public RCSB PDB database. The proteins were optimized using the APBS server, which added charges, polar hydrogens, water molecules, and cocrystallized components. The enzymes were subsequently removed. In this study, the amoebicidal potential of the molecules isoeleutherin, eleutherin, isoeleutherol, and eleutherol was evaluated. In in silico studies, in MM/GBSA energy calculations, isoeleuterin was the most promising ligand (-27.67 kcal/mol) in the EhTrxR target, while in the EhOASS target, it maintained a competitive binding energy (-20.30 kcal/mol), being the most promising natural compound. In addition, it has a lower toxicity profile. The search for therapeutic alternatives for the treatment of amoebiasis is important, with in silico studies being one strategy. Isoeleuterin is the most promising molecule for in vitro and in vivo validation studies.

Teucrium polium L. is a plant with various claims of ethnobotanical use, primarily for in-flammatory diseases. Chemical studies have already isolated different types of terpenes from the species, and studies have established the pharmacological potential. The present study evaluated the components of T. polium essential oil cultivated in Algerian Saharan Atlas. GC-MS identified the major components as Fenchone (31.25%), 3-Carene (15.77%), cis-Limonene oxide (9.77%), and Myrcene (9.15%). In the in silico prediction, molecules with more than 1% abundance were selected. Regarding Lipinski’s rule, all molecules fol-lowed the rule. All molecules were found to be toxic in at least one model, with some mol-ecules being non-genotoxic (6, 8, 10, 11, 12, 13), others being non-mutagenic (5, 7, 9, 14). Three molecules were selected that showed the best results in pharmacokinetic and toxici-ty studies: the molecules that did not present carcinogenic potential (7 - Myrtenal; 9 - Myr-tenol; 14 – Verbenol). The molecular target was established and it seems that all three bind to the Nuclear Factor NF-kappa-B. Based on the docking and molecular dynamics results. These molecules have potential as anti-inflammatory agents, with further in vitro and in vivo studies needed to evaluate their activities and toxicity.