Trichomonas vaginalis is a protist parasite of the urogenital tract, responsible for human trichomoniasis, an infection sexually transmitted that affects approximately 156 million people worldwide. This pathology is more evident in females and can cause miscarriages, premature births, and infertility. The disease can also lead to a greater predisposition to HIV infection and cervical and prostate cancer. Metronidazole (MTZ) is a drug that treats human trichomoniasis. The data from studies involving human subjects are limited regarding MTZ use during pregnancy. In addition to the toxicity of the treatment, some isolates have become resistant to MTZ. Therefore, searching for new compounds active for treating trichomoniasis becomes necessary. In the present study, we report results obtained using new phospholipid analogs. Two cardanol-based compounds designated LDT117 and LDT134 were active against T. vaginalis with an IC

The World Health Organization recommends the use of the Kato-Katz method in the procedures of schistosomiasis control programs. Studies show the importance of a fast reading of the slides due to the decline of their viability, with the appearance of fungi or desiccation of the sample, which hinders diagnosis. It is necessary to establish a procedure to improve the long-term preservation of these Kato-Katz slides in order to accomplish the following: (1) preserve the slides for future quality control procedures and readings; (2) allow for the production of durable materials for training; and (3) train health professionals involved in diagnosing schistosomiasis. Therefore, this study aims to test a slide preservation methodology for these purposes. The results showed that the modifications made to the experimental slides demonstrated that egg loss was within the expected range and the limit accepted by quality control standards, as well as improved the diagnostic durability of the slides during the preservation times tested. We concluded that the application of the preservation technique to the slides promoted stabilization and permanence for long-term storage.

This study aimed to develop microemulsions (MEs) containing α-bisabolol for the topical treatment of cutaneous leishmaniasis (CL). Initially, pseudoternary phase diagrams were developed using α-bisabolol as the oil phase, Eumulgin® CO 40 as the surfactant, Polymol® HE as the co-surfactant, and distilled water as the aqueous phase. Two transparent liquid systems (TLS) containing 5% of α-bisabolol were selected and characterized (F5E25 and F5EP25). Next, skin permeation and retention assays were performed using Franz cells. The interaction of the formulation with the stratum corneum (SC) was evaluated using the FTIR technique. The cytotoxicity was evaluated in murine peritoneal macrophages. Finally, the antileishmanial activity of microemulsions was determined in promastigotes and amastigotes of L. amazonensis (strain MHOM/BR/77/LTB 0016). As a result, the selected formulations showed isotropy, nanometric size (below 25 nm), Newtonian behavior and pH ranging from 6.5 to 6.9. The MEs achieved a 2.5-fold increase in the flux and skin-permeated amount of α-bisabolol. ATR-FTIR results showed that microemulsions promoted fluidization and extraction of lipids and proteins of the stratum corneum, increasing the diffusion coefficient and partition coefficient of the drug in the skin. Additionally, F5E25 and F5EP25 showed higher activity against promastigotes (IC

Trichomonas vaginalis is the etiologic agent of trichomoniasis, a worldwide distributed sexually transmitted infection (STI) that affects the genitourinary tract. Even though this disease already has a treatment in the prescription of drugs of the 5-nitroimidazole class, described low treatments adhesion, adverse side effects and cases of resistant isolates demonstrate the need for new formulations. With this in mind, chalcones emerge as a potential alternative to be tested, being compounds widely distributed in nature, easy to chemically synthesize and presenting several biological activities already reported. In this experiment, we evaluated the antiparasitic activity of 10 chalcone at a concentration of 100 μM against ATCC 30236 T. vaginalis isolates, considering negative (live trophozoites), positive (Metronidazole 100 μM) and vehicle (DMSO 0.6%) controls. Compounds 3a, 3c, 3g and 3i showed promising results, with MICs set at 70 μM, 80 μM, 90 μM and 90 μM, respectively (p

Infections caused by the ectoparasite Rhipicephalus microplus can cause major health problems in cattle, including death. Tick control is regularly made using a range of acaricide products. As a consequence, tick populations have been heavily selected for drug resistance. The objective of this work was to determine the in vitro efficacy of copper chloride and sulfate (CuCl2 and CuSO4) solutions against R. microplus. The adult immersion test (AIT), which measures the egg-laying and egg-hatch effects, was used for the Cu-II solutions at 30, 60, 120, 240, 480, and 1000 mM, in triplicates. Distilled water and the combination of cypermethrin 20% and chlorpyrifos 50% were used as controls. Histological sections were performed from the ovaries of adult engorged female ticks treated with 240, 480, and 1000 mM of CuCl2 and CuSO4. We have established a histological index of the damage caused by the solutions to the tick oocytes. The overall efficacy (egg laying & egg hatch) for CuCl2 and CuSO4 was 81.3, 82.5, 89.8, 84.5, 100.0, and 100%, and 61.7, 43.4, 62.5, 93.1, 100.0, and 98.5% respectively. Smaller oocytes were found in the Cu-II groups compared to the negative control. The histological data showed a concentration-dependent degenerative lesion of oocytes, described as cytoplasmic vacuolation and nuclear disorganization. The combination of cypermethrin and chlorpyriphos showed 100% efficacy. Cu-II solutions showed in vitro efficacy against adult engorged ticks being particularly harmful to oocytes. Thus, bioactive metals could be a complementary biofriendly treatment to control R. microplus and these injuries could be responsible for preventing egg hatch, and reducing pasture contamination. Safety studies are underway demonstrating the Cu-II potential in naturally infected cattle and their persistence in the environment.

Despite all the scientific progress in recent decades to unravel the immune processes and the way the parasite bypasses the immune system, Chagas disease is still a major public health problem, affecting an estimated 3.5 million people. Among the components that may participate in the response against the parasite, testosterone has been gaining more and more visibility. Studies indicate that the parasite itself seems to carry out steroidogenesis, in which, in co-culture with androgen precursors, T. cruzi has been shown to produce TS, but the purpose of the TS synthesized by the parasite and how this can influence its invasion glycoproteins is still unclear unknown. The aim of this study was to evaluate the influence of testosterone in Trypanosoma cruzi infection on the immune response of bone marrow-derived macrophages. Bone marrow from male rats was extracted and cultured with RMPI medium containing 30% L929 cell supernatant for macrophage differentiation. The cells were incubated for 10 days and, after this period, they were seeded in 96 wells in the amount of 1 x 10

Research on the use of entomopathogenic nematodes (EPNs) as a potential tool for the biological control of invertebrates has been growing in recent years, including studies involving snails with One Health importance. In this study, the effect of exposure time (24 or 48 h) of Heterorhabditis bacteriophora HP88 on the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as well as the concentration of total proteins, uric acid, and urea in the hemolymph of Biomphalaria glabrata, were investigated. The concentrations of these metabolic markers were measured weekly until the end of the third week after exposure. Along with a significant reduction in total protein levels, a significant increase (p < 0.01) in uric acid and urea contents in the hemolymph of B. glabrata exposed to H. bacteriophora was observed. The accumulation of urea in these mollusks could lead to deleterious effects due to its high toxicity, inducing significant cell damage. Variations in transaminase activities were also observed, with snails exposed to EPNs showing significantly higher values (p < 0.01) than individuals in the control group, both for ALT and AST. These results indicate that experimental exposure to infective juveniles of H. bacteriophora causes significant alterations in the metabolic pattern of B. glabrata, compromising the maintenance of its homeostasis. Finally, exposure for 48 h caused more damage to the planorbid in question compared to snails exposed for 24 h, suggesting that the exposure time may influence the intensity of the host's response.

New affordable drugs are needed for the treatment of infection with the protozoan parasite Trypanosoma cruzi responsible for the Chagas disease (CD). Only two old drugs are currently available, nifurtimox and benznidazole (Bz) but they exhibit unwanted side effects and display a weak activity in the late chronic phase of the disease. In this context, we evaluated the activity of a series of aryl-pyrazolone derivatives against T cruzi, using both bloodstream trypomastigote and intracellular amastigote forms of the parasite. The test compounds originate from a series of anticancer agents targeting the immune checkpoint ligand PD-L1 and bear an analogy with known anti-trypanosomal pyrazolones. A first group of 6 phenyl-pyrazolones was tested, revealing the activity of a single pyridyl-pyrazolone derivative. Then a second group of 8 compounds with a common pyridyl-pyrazolone core was evaluated. The in vitro testing process led to the identification of two non-cytotoxic and highly potent molecules against the intracellular form of T. cruzi, with an activity comparable to Bz. Moreover, one compound revealed an activity largely superior to that of Bz against bloodstream trypomastigotes, while being non-cytotoxic (selectivity index >1000). Unfortunately, the compound showed little activity in vivo, most likely due to its very limited plasma stability. However, the study opens novel perspectives for the design of new anti-trypanosomal products and the mechanism of action of the compounds is discussed.

Piroplasmids and Hepatozoon spp. are apicomplexan protozoa that may cause disease in several canid species. The present study aimed to expand the knowledge on the diversity of piroplasmids and Hepatozoon in crab-eating foxes (Cerdocyon thous; n=12) sampled in the Pantanal of Mato Grosso do Sul State, central-western Brazil. PCR assays based on the 18S rRNA were used as screening. Three (25%) and 11 (91.7%) were positive for piroplasmids and Hepatozoon spp., respectively. Co-infection was found in three C. thous. Phylogenetic analyses based on the near-complete 18S rRNA, cox-1 and hsp70 genes evidenced the occurrence of a novel of Babesia spp. (namely Babesia pantanalensis nov. sp.) closely related to Rangelia vitalii and Babesia sp. 'Coco'. This finding was supported by the genetic divergence analysis which showed (i) high divergence, ranging from 4.17 to 5.62% for 18S rRNA, 6.16% for hps70 and 4.91 to 9.25% for cox-1 and (ii) the genotype network (which displayed sequences separated from the previously described Piroplasmida species by median vectors and several mutational events). Also, phylogenetic analysis based on the 18S rRNA gene of Hepatozoon spp. positioned the sequences obtained herein in a clade phylogenetically related to Hepatozoon sp. 'Curupira 2', Hepatozoon sp. detected in domestic and wild canids from Uruguay and Hepatozoon americanum. The present study described Babesia pantanalensis nov sp. and Hepatozoon closely related to H. americanum in crab-eating foxes from Brazil. Moreover, the coinfection by piroplasmids and Hepatozoon sp. for the first time in crab-eating foxes strongly suggesting that this wild canid species potentially acts as a bio-accumulate of hemoprotozoan in wild environment.

Toxoplasmosis affects about one-third of the world's population. The disease treatment methods pose several side effects and do not efficiently eliminate the parasite, making the search for new therapeutic approaches necessary. We aimed to assess the anti-Toxoplasma gondii activity of four Copaifera oleoresins (ORs) and two isolated diterpene acids, named ent-kaurenoic and ent-polyalthic acid. We used HeLa cells as an experimental model of toxoplasmosis. Uninfected and infected HeLa cells were submitted to the treatments, and the parasite intracellular proliferation, cytokine levels and ROS production were measured. Also, tachyzoites were pre-treated and the parasite invasion was determined. Finally, an in silico analysis was performed to identify potential parasite targets. Our data show that the non-cytotoxic concentrations of ORs and diterpene acids controlled the invasion and proliferation of T. gondii in HeLa cells, thus highlighting the possible direct action on parasites. In addition, some compounds tested controlled parasite proliferation in an irreversible manner. An additional and non-exclusive mechanism of action involves the modulation of host cell components, by affecting the upregulation of the IL-6. Additionally, molecular docking suggested that ent-polyalthic acid has a high affinity for the active site of the TgCDPK1 protein. Copaifera ORs have great antiparasitic activity against T. gondii, and this effect can be partially explained by the presence of the isolated compounds ent-kaurenoic and ent-polyalthic acid.

Neurocysticercosis (NCC) is a parasitic infection caused by the larval stage of the pork tapeworm, Taenia solium. The complications of NCC include seizures, headaches, cognitive impairment, and focal neurological deficits. In addition to antiparasitic drugs and surgery, the management of NCC includes the use of corticosteroids to reduce inflammation and control symptoms. The traditional treatment with albendazole and praziquantel has not been altered over 30 years and present several side effects. There are other anti-helminthic drugs such as oxfendazole and nitazoxanide that may show efficacy in NCC treatment. The aim of this study was to determine the histopathologic aspects of experimental NCC after in vivo treatment with the combination of oxfendazole and nitazoxanide. Balb/c mice were infected with T. crassiceps cysticerci and divided into groups of 10 animals each that received a single dose through gavage as follows: group treated with NaCl 0.9% (control group); group treated by monotherapy of the anti-helminthic drugs, 30 mg/kg in single dose of oxfendazole (OXF) or nitazoxanide (NTZ); and groups treated with the combination of the drugs (OXF/NTZ group). Macroscopic and microscopic analysis were performed. There was greater presence of final stage cysticerci after treatment. The microscopic analysis of the general pathological processes showed that the monotherapy with all treatment groups induced higher perivasculitis than what was observed in the control group. In contrast, the combination treatment showed a lower observation of PMN and MN inflammatory infiltration in comparison to the other treatments and to the control one. These results show that indeed the association of benzimidazole derivatives which present both anti-helminthic and anti-inflammatory properties with other cysticidal drugs are beneficial for the NCC treatment in which the aim is to destroy parasite without inducing inflammatory damage in the brain tissue.

Trypanosoma cruzi (T. cruzi) causes Chagas, which is a neglected tropical disease (NTD). WHO estimates that 6 to 7 million people are infected worldwide. Current treatment is done with benznidazole (BZN), which is very toxic and effective only in the acute phase of the disease. In this work, we designed, synthesized, and characterized thirteen new phenoxyhydrazine-thiazole compounds and applied molecular docking and in vitro methods to investigate cell cytotoxicity, trypanocide activity, nitric oxide (NO) production, cell death, and immunomodulation. We observed a higher predicted affinity of the compounds for the squalene synthase and 14-alpha demethylase enzymes of T. cruzi. Moreover, the compounds displayed a higher predicted affinity for human TLR2 and TLR4, were mildly toxic in vitro for most mammalian cell types tested, and LIZ531 (IC50 2.8 μM) was highly toxic for epimastigotes, LIZ311 (IC50 8.6 μM) for trypomastigotes, and LIZ331 (IC50 1.9 μM) for amastigotes. We observed that LIZ311 (IC50 2.5 μM), LIZ431 (IC50 4.1 μM) and LIZ531 (IC50 5 μM) induced 200 μg/mL of NO and JM14 induced NO production in three different concentrations tested. The compound LIZ331 induced the production of TNF and IL-6. LIZ311 induced the secretion of TNF, IFNγ, IL-2, IL-4, IL-10, and IL-17, cell death by apoptosis, decreased acidic compartment formation, and induced changes in the mitochondrial membrane potential. Taken together, LIZ311 is a promising anti-T. cruzi compound is not toxic to mammalian cells and has increased antiparasitic activity and immunomodulatory properties.

The apicomplexa Toxoplasma gondii is capable of actively proliferating in numerous types of nucleated cells, and therefore has a high potential for dissemination and resistance. Thus, the present work aimed to correlate the inoculum concentrations and amount of post-infection parasites with porcine hematological parameters (including biochemistry) through in vitro culture. Porcine blood was incubated with different concentrations of parasites (1.2 x 107, 6 / 3 / 1.5 x 106 cells/mL), then the concentrations of red blood cells (RBC) and their morphology, total and differential leukocytes, and free peptides were evaluated. In addition, eight different blood samples analyzed before inoculation, where subsequent multivariate analysis was applied to correlate different variables with trophozoite concentration. The results showed no significant variation (p < 0.05) in the relative levels of free peptides, or the relative percentage of RBC at all the parasite concentrations tested. However, the normalized percentages of leukocytes and neutrophils showed a significant reduction, while those of lymphocytes, eosinophils and monocytes showed the opposite behavior. Semi-automatic processing of images exhibited significant microcytosis and hypochromia. The multivariate analysis revealed a positive correlation between the amount number of protozoa (AP) and the variables: "Red cells" and "Neutrophils", an indifference between the AP and the content of free peptides, and the concentration of monocytes in the samples; and a negative correlation for AP and the percentages of lymphocytes and eosinophils. Our results suggest that specific changes in hematological parameters may be associated with different degrees of parasitemia, demanding a thorough diagnostic process and adequate treatment.

Amoebiasis is a disease caused by Entamoeba histolytica, affecting the large intestine of humans and occasionally leading to extra-intestinal lesions. Entamoeba dispar is another amoeba species considered commensal, although it has been identified in patients presenting with dysenteric and nondysenteric colitis, as well as amoebic liver abscess. Amoebic virulence factors are essential for the invasion and development of lesions. There is evidence showing that the association of enterobacteria with trophozoites contributes to increased gene expression of amoebic virulence factors. Enteropathogenic Escherichia coli is an important bacterium causing diarrhea, with high incidence rates in the world population, allowing it to interact with Entamoeba sp. in the same host. In this context, this study aims to evaluate the influence of enteropathogenic Escherichia coli on ACFN and ADO Entamoeba dispar strains by quantifying the gene expression of virulence factors, including galactose/N-acetyl-D-galactosamine-binding lectin, cysteine proteinase 2, and amoebapores A and C. Additionally, the study assesses the progression and morphological aspect of amoebic liver abscess and the profile of inflammatory cells. Our results demonstrated that the interaction between EPEC and ACFN Entamoeba dispar strains was able to increase the gene expression of virulence factors, as well as the lesion area and the activity of the inflammatory infiltrate. However, the association with the ADO strain did not influence the gene expression of virulence factors. Together, our findings indicate that the interaction between EPEC, ACFN, and ADO Entamoeba dispar strains resulted in differences in vitro and in vivo gene expression of Gal/GalNAc-binding lectin and CP2, in enzymatic activities of MPO, NAG, and EPO, and consequently, in the ability to cause lesions.

Treatment against leishmaniasis presents problems, mainly due to the toxicity of the drugs, high cost, and the emergence of resistant strains. A previous study showed that two vanillin-derived synthetic molecules, 3s [4-(2-hydroxy-3-(4-octyl-1H-1,2,3-triazol-1-yl)propoxy)-3-methoxybenzaldehyde] and 3t [4-(3-(4-decyl-1H-1,2,3-triazol-1-yl)-2-hydroxypropoxy)-3-methoxybenzaldehyde], presented antileishmanial activity against Leishmania infantum, L. amazonensis, and L. braziliensis species. In the present work, 3s and 3t were evaluated to treat L. amazonensis-infected mice. Molecules were used pure or incorporated into Poloxamer 407-based micelles. In addition, amphotericin B (AmpB) and its liposomal formulation, Ambisome®, were used as control. Animals received the treatment and, one and 30 days after, they were euthanized to evaluate immunological, parasitological, and biochemical parameters. Results showed that the micellar compositions (3s/Mic and 3t/Mic) induced significant reductions in the lesion mean diameter and parasite load in the infected tissue and distinct organs, as well as a specific and significant antileishmanial Th1-type immune response, which was based on significantly higher levels of IFN-γ, IL-12, nitrite, and IgG2a isotype antibodies. Drug controls showed also antileishmanial action; although 3s/Mic and 3t/Mic have presented better and more significant parasitological and immunological data, which were based on significantly higher IFN-γ production and lower parasite burden in treated animals. In addition, significantly lower levels of urea, creatinine, alanine transaminase, and aspartate transaminase were found in mice treated with 3s/Mic and 3t/Mic, when compared to the others. In conclusion, results suggest that 3s/Mic and 3t/Mic could be considered as therapeutic candidates to treat against L. amazonensis infection.

In Schistosoma mansoni infection, the spleen is one of the organs affected, causing its enlargement (splenomegaly). Intake of ethanol through alcoholic beverages can cause spleen atrophy and interfere with immune activity. To gain knowledge of this association on the spleen and on the immune response profile, male mice were used as an experimental model. These animals were divided into four groups: C. control; EC. uninfected/ethanol gavage; I. infected; and IE. infected/ethanol gavage. Groups I and IE were infected with about 100 cercariae (BH strain) of S. mansoni and in the fifth week of infection, gavage 200 μL/day/animal of 18 % ethanol was started for 28 consecutive days. At the end of the gavage (9th week of infection) all animals were euthanized. The spleen was removed and longitudinally divided in two parts. After histological processing, the sections were stained with H&E and Gomori's Reticulin for histopathological and stereological analyses, white pulp morphometry and quantification of megakaryocytes. The other fragment was macerated (in laminar flow) and the cell suspension, after adjusting the concentration (2 × 106), was plated to obtain cytokines produced by spleen cells that were measured by flow cytometry (Citometric Bead Array). Histopathological and quantitative analyzes in the spleen of the IE group showed an increase in the number of trabeculae and megakaryocytes, a decrease in reticular fibers, as well as important organizational changes in the white pulp and red pulp. Due to the decrease in the levels of cytokines measured and the result of the calculation of the ratio between the IFN-y and IL-10 cytokines (p = 0.0079) of the infected groups, we suggest that ethanol decreased the inflammatory and anti-inflammatory response generated by the infection (group IE, the production of cytokines was significantly decreased (p < 0.01). These changes demonstrate that ethanol ingestion interferes with some parameters of experimental S. mansoni infection, such as changes in splenic tissue and in the pattern of cytokine production.

Schistosomiasis is a neglected disease transmitted through contaminated water in populations with low basic sanitation. The World Health Organization recommends controlling the intermediate host snails of the Biomphalaria genus with the molluscicide niclosamide. This work aims to evaluate the biocidal potential of the nanoemulsion prepared with the essential oil of Ocotea indecora leaves for the control of the mollusk Biomphalaria glabrata, intermediate host of the Schistosoma mansoni, the etiologic agent of schistosomiasis.

Trichomonas vaginalis is an extracellular flagellate protozoan and the etiological agent of human trichomoniasis, a sexually transmitted infection (STI) with a high incidence. Several reports have shown that this protozoan releases microvesicles into the culture medium, which show high potential in modulating cell-to-cell communication and the host response to infections. However, the biogenesis of these vesicles has not been analyzed in detail. In the present study, high-resolution ion scanning microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the surface of control cells and cells incubated in the presence of Ca2+ alone or with A 23187 calcium ionophore. Two different strains of T. vaginalis were analyzed. Most control cells displayed relatively smooth surfaces, whereas cells incubated with Ca2+ had many surface projections of variable shape and size (from 40 nm to around 1 μm). Quantitative analyses were performed directly in the scanning electron microscope and showed a significant increase in the number of cells with surface projections after incubation in the presence of calcium. TEM showed that treated cells presented several cytoplasmic multivesicular structures, suggesting membrane fusion and exosomes in the extracellular medium. The amount and size of the released vesicles were quantitatively analyzed using light scattering and TEM on negatively stained samples. The observations show that incubation of both parasite strains in the presence of Ca2+ significantly increased the release of microvesicles into the extracellular medium in a time-dependent process. Sequential incubation in the presence of Ca2+ and the calcium ionophore A23187 increases the presence of vesicles on the parasite surface only at a short incubation time (5 min). Transmission electron microscopy showed that at least part of the vesicles are originated from cytoplasmic multivesicular structures. This information contributes to a better understanding of the biogenesis of extracellular vesicles secreted by T. vaginalis.

Toxoplasmosis is a zoonosis that is a worldwide health problem, commonly affecting fetal development and immunodeficient patients. Treatment is carried out with a combination of pyrimethamine and sulfadiazine, which can cause cytopenia and intolerance and does not lead to a parasitological cure of the infection. Lysine deacetylases (KDACs), which remove an acetyl group from lysine residues in histone and non-histone proteins are found in the Toxoplasma gondii genome. Previous work showed the hydroxamate-type KDAC inhibitors Tubastatin A (TST) and Vorinostat (Suberoylanilide Hydroxamic Acid, SAHA) were effective against T. gondii. In the present study, the effects of three hydroxamates (KV-24, KV-30, KV-46), which were originally designed to inhibit human KDAC6, showed different effects against T. gondii. These compounds contain a heterocyclic cap group and a benzyl linker bearing the hydroxamic acid group in para-position. All compounds showed selective activity against T. gondii proliferation, inhibiting tachyzoite proliferation with IC50 values in a nanomolar range after 48h treatment. Microscopy analyses showed that after treatment, tachyzoites presented mislocalization of the apicoplast, disorganization of the inner membrane complex, and arrest in the completion of new daughter cells. The number of dividing cells with incomplete endodyogeny increased significantly after treatment, indicating the compounds can interfere in the late steps of cell division. The results obtained in this work that these new hydroxamates should be considered for future in vivo tests and the development of new compounds for treating toxoplasmosis.

Human toxocariasis is a parasitic anthropozoonosis that is difficult to treat and control. A previous study carried out with Lactobacillus acidophilus ATCC 4356 revealed that the cell free supernatant (CFS) of this probiotic killed 100% of Toxocara canis larvae in vitro. The present study aimed to investigate the characteristics of the CFS of L. acidophilus ATCC 4356, which may be involved in its larvicidal effects on T. canis. L. acidophilus ATCC 4356 was cultured, and lactic and acetic acids present in the CFS were quantified by high performance liquid chromatography (HPLC). The levels of pH and H2O2 were also analyzed. To assess the larvicidal effect of the CFS, this was tested pure and diluted (1:2 to 1:128) on T. canis larvae. High concentrations of lactic and acetic acids were detected in the CFS. The acidity of the pure CFS was observed at pH 3.8, remaining acidic at dilutions of 1:2 to 1:16. Regarding the in vitro larvicidal effect, 100% death of T. canis larvae was observed using the pure CFS and 1:2 dilution. Based on these results, it can be inferred that the presence of higher concentrations of organic acids and low pH of the medium contributed to the larvicidal activity of the CFS of L. acidophilus ATCC 4356. In addition, the maintenance of the larvicidal effect, even after dilution, suggests a greater chance of the larvicidal effect of this CFS against T. canis in vivo.

Aedes aegypti serves as the primary vector for viruses like dengue, Chikungunya, Zika, and yellow fever, posing a significant public health challenge in Brazil. Given the absence of approved vaccines for these diseases, effective mosquito control becomes paramount in preventing outbreaks. However, currently available chemical insecticides face issues related to toxicity and the emergence of resistance, necessitating the exploration of new active compounds. Drawing inspiration from natural products, we identified the 1,3-benzodioxole group as a key pharmacophore associated with insecticidal activity. Therefore, this study aimed to synthesize and assess the larvicidal activity of 1,3-benzodioxole acids against Ae. aegypti, as well as their toxicity in mammals. Among the compounds evaluated, 3,4-(methylenedioxy) cinnamic acid (compound 4) demonstrated larvicidal activity. It exhibited LC50 and LC90 values of 28.9 ± 5.6 and 162.7 ± 26.2 μM, respectively, after 24 h of exposure. For reference, the positive control, temephos, displayed both LC50 and LC90 values below 10.94 μM. These findings underline the significance of the 3,4-methylenedioxy substituent on the aromatic ring and the presence of a double bond in the aliphatic chain for biological activity. Furthermore, compound 4 exhibited no cytotoxicity towards human peripheral blood mononuclear cells, even at concentrations up to 5200 μM. Lastly, in mice treated with 2000 mg kg-1, compound 4 showed mild behavioral effects and displayed no structural signs of toxicity in vital organs such as the kidney, liver, spleen, and lungs.

Among all the neglected diseases, schistosomiasis is considered the second most important parasitic infection after malaria. Praziquantel is the most widely used drug for this disease, but its exclusive use may result in the development of drug-resistant schistosomiasis. To increase the control of the disease, new drugs have been developed as alternative treatments, among them 2-(-5-bromo-1-h-indole-3-yl-methylene)-N-(naphthalene-1-ylhydrazine-carbothiamide (LQIT/LT-50), which showed promising schistosomicidal activity in nonclinical studies. However, LQIT/LT-50 presents low solubility in water, resulting in reduced bioavailability. To overcome this solubility problem, the present study aimed to develop LQIT/LT-50 solid dispersions for the treatment of schistosomiasis. Solid dispersions were prepared through the solvent method using Soluplus©, polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP K-30) as hydrophilic carriers. The formulations with the best results in the compatibility tests, aqueous solubility and preliminary stability studies have undergone solubility tests and physicochemical characterizations by Fourier-transform infrared spectroscopy (FTIR), x-ray diffractometry (XRD), exploratory differential calorimetry (DSC), thermogravimetry (TG) and Raman spectroscopy. Finally, the schistosomicidal activity was evaluated in vitro. The phycochemical analyzes showed that when using PVP K-30, there was an interaction between the PVP K-30 and LQIT/LT-50, proving the successful development of the solid dispersion. Furthermore, an increase in the solubility of the new system was observed (LQIT/LT-50:PVP K-30) in addition to the improvement in the in vitro shistosomidal activity at 1:4 (w/w) molar ratio (i.e., 20% drug loading) when compared to LQIT/LT-50 alone. The development of the LQIT/LT-50:PVP K-30 1:4 solid dispersion is encouraging for the future development of new pharmaceutical solid formulations, aiming the schistosomicidal treatment.

Schistosomiasis is a parasitic disease that can be asymptomatic, but it can progress and cause serious damage, such as hospitalization and death. This work aimed to characterize and carry out the in vivo pharmacological test of the dry extract of Morinda citrifolia and obtain a pharmaceutical dosage form based on this extract for the treatment of schistosomiasis. The aqueous extract was characterized based on the evaluation of pH, dry residue and density. The aqueous extract was dried through the freeze-drying process. The obtained dry extract was characterized through phytochemical screening, rheological analysis, acute toxicity and in vivo pharmacology. Additionally, the pre-formulation development of a pharmaceutical dosage form was pursued with the dry extract. Through the HPLC chromatogram, characteristic rutin peaks were identified. The rheological behavior of the dry extract did not show good characteristics. Acute toxicity, at a dose of 2000 mg/kg, showed excitatory activity in the central and autonomous nervous system. The in vivo pharmacological test of the dry extract showed that, at a dose of 400 mg/kg, it was possible to reduce 67.5% of the total adult worms, 66% of female worms and 60% of the number of eggs. The pharmaceutical dosage form obtained was an oral solution that was clear, transparent, without the presence of lumps and precipitates, having a density of 1.1276 g mL-1 and pH of 5.92. The results obtained will provide parameters for the production of suitable pharmaceutical formulations, as well as for the quality control of products based on M. citrifolia, with promising schistosomicidal activity.