A standardized intraperitoneal Glucantime™ for experimental treatment of cutaneous leishmaniasis caused by Leishmania amazonensis in BALB/c mice

Exploring the binomial BALB/c-Leishmania (Viannia) braziliensis model to assess the in vivo performance of Thor strain subpopulations

Leishmania (Viannia) braziliensis is associated with distinct clinical manifestations such as cutaneous, mucocutaneous, and disseminated leishmaniasis. One factor related to this clinical spectrum is the structure of parasite populations. This study investigates in vivo binomial BALB/c-L. (V.) braziliensis exploring the phenotypic variability of subpopulations (Thor03, Thor10 and Thor22) of Thor strain, which have previously been described as causing distinct pattern infection in vitro. In the third week after infection, differences were observed in the development curves of the lesions, with larger lesions in the Thor03 and Thor10. At this point, lymph nodes of mice infected with the Thor03 and Thor10 exhibited lower IL-12 and TNF values compared to infection with the Thor strain and Thor22. The infection with the Thor10 showed highest values of the cytokine IL-10 compared to those infected with the Thor strain, Thor03 and Thor22. In addition, no statistical differences in parasite load wer observed in the footpad in seventh week post inoculation. In contrast, the higher parasite load values were observed in the lymph nodes for Thor03, Thor10 and Thor22 subpopulations. The data obtained here show these subpopulations cause transient and non-severe footpad lesions with parasite persistence in draining lymph nodes, although some mice developed non-healing lesions. Parasites isolated from the paws and lymph nodes of these animals were unable to establish persistent lesions in subsequent experimental infection assays. Collectively, these findings highlight consistent differences of infectionevolution and host immune response modulation, during infection among the Thor03, Thor10 and Thor22 subpopulations , all derived from a single strain.

From clove oil to bioactive agents: synthetic routes, antimicrobial and antiparasitic activities of eugenol derivatives

Eugenol, a natural compound found in essential oils such as clove oil, has been extensively studied for its diverse biological activities including the therapeutic potential against microbial and parasitic infections. This review provides an overview of the synthetic strategies (shown in Supplementary Material) employed to develop bioactive derivatives and analogues derived from eugenol and related compounds (e.g., dihydroeugenol and isoeugenol), focusing on biological activity of more than 100 bioactive eugenol derivatives against bacterial, fungal, viral and protozoal pathogens. Through a comprehensive survey of literature, this paper shows the impact of structural modifications of these phenylpropanoids on antimicrobial and antiparasitic activity. Key findings highlight promising candidates for further development in antimicrobial drug discovery, suggesting directions for future research in the pursuit of effective therapeutic agents.

Leishmanicidal and immunomodulatory properties of Brazilian green propolis extract (EPP-AF®) and a gel formulation in a pre-clinical model

Leishmaniasis is a widespread group of neglected vector-borne tropical diseases that possess serious therapeutic limitations. Propolis has been extensively used in traditional medical applications due to its range of biological effects, including activity against infectious agents. Here we evaluated the leishmanicidal and immunomodulatory properties of Brazilian green propolis extract (EPP-AF^®) and a gel formulation incorporating EPP-AF^®, in both in vitro and in vivo models of Leishmania amazonensis infection. Propolis extract, obtained from a standardized blend following hydroalcoholic extraction, showed the characteristic fingerprint of Brazilian green propolis as confirmed by HPLC/DAD. A carbopol 940 gel formulation was obtained containing propolis glycolic extract at 3.6% w/w. The release profile, assessed using the Franz diffusion cell protocol, demonstrated a gradual and prolonged release of p-coumaric acid and artepillin C from the carbomer gel matrix. Quantification of p-coumaric acid and artepillin C in the gel formulation over time revealed that p-coumaric acid followed the Higuchi model, dependent on the disintegration of the pharmaceutical preparation, while artepillin C followed a zero-order profile with sustained release. In vitro analysis revealed the ability of EPP-AF^® to reduce the infection index of infected macrophages (p < 0.05), while also modulating the production of inflammatory biomarkers. Decreases in nitric oxide and prostaglandin E₂ levels were observed (p < 0.01), suggesting low iNOS and COX-2 activity. Furthermore, EPP-AF^® treatment was found to induce heme oxygenase-1 antioxidant enzyme expression in both uninfected and L. amazonensis-infected cells, as well as inhibit IL-1β production in infected cells (p < 0.01). ERK-1/2 phosphorylation was positively correlated with TNF-α production (p < 0.05), yet no impact on parasite load was detected. In vivo analysis indicated the effectiveness of topical treatment with EPP-AF^® gel alone (p < 0.05 and p < 0.01), or in combination with pentavalent antimony (p < 0.05 and p < 0.001), in the reduction of lesion size in the ears of L. amazonensis-infected BALB/c mice after seven or 3 weeks of treatment, respectively. Taken together, the present results reinforce the leishmanicidal and immunomodulatory effects of Brazilian green propolis, and demonstrate promising potential for the EPP-AF^® propolis gel formulation as a candidate for adjuvant therapy in the treatment of Cutaneous Leishmaniasis.

Antibacterial, Antiparasitic, and Cytotoxic Activities of Chemical Characterized Essential Oil of Chrysopogon zizanioides Roots

This study aimed to investigate the chemical composition as well as the antibacterial, antiparasitic, and cytotoxic potentialities of the Brazilian Chrysopogon zizanioides root essential oil (CZ-EO) In addition, CZ-EO cytotoxicity to LLCMK₂ adherent epithelial cells was assessed. The major compounds identified in CZ-EO were khusimol (30.0 ± 0.3%), β-eudesmol (10.8 ± 0.3%), α-muurolene (6.0 ± 0.1%), and patchouli alcohol (5.6 ± 0.2%). CZ-EO displayed optimal antibacterial activity against Prevotella nigrescens, Fusobacterium nucleatum, Prevotella melaninogenica, and Aggregatibacter actinomycetemcomitans, with Minimum Inhibitory Concentration (MIC) values between 22 and 62.5 µg/mL and Minimum Bactericidal Concentration (MBC) values between 22 and 400 µg/mL. CZ-EO was highly active against the L. amazonensis promastigote and amastigote forms (IC₅₀ = 7.20 and 16.21 µg/mL, respectively) and the T. cruzi trypomastigote form (IC₅₀ = 11.2 µg/mL). Moreover, CZ-EO showed moderate cytotoxicity to LLCMK₂ cells, with CC₅₀ = 565.4 µg/mL. These results revealed an interesting in vitro selectivity of CZ-EO toward the L. amazonensis promastigote and amastigote forms (Selectivity Index, SI = 78.5 and 34.8, respectively) and the T. cruzi trypomastigote form (SI = 50.5) compared to LLCMK₂ cells. These results showed the promising potential of CZ-EO for developing new antimicrobial, antileishmanial, and antitrypanosomal drugs.