[This corrects the article DOI: 10.3389/fpara.2025.1523113.].

Trichomonas vaginalis is a flagellated protozoan causing trichomoniasis, the most common non-viral sexually transmitted infection. It is associated with various complications, particularly in asymptomatic carriers. Another major cause of vaginitis is Candida albicans, a normal member of the vaginal microbiota, which causes vulvovaginal candidiasis when immune imbalances occur, leading to recurrent infections. Treatment-resistant strains of these pathogens pose a significant challenge. Lactobacillus crispatus, a dominant species in the vaginal microbiota, produces antimicrobial compounds that help protect the vaginal mucosa. This study establishes an in vitro co-culture of T. vaginalis, C. albicans, and L. crispatus to simulate the vaginal microenvironment at the site of infection. MRS medium was chosen for the co-culture, with initial cell densities determined as follows: T. vaginalis at 1.0 x 106 trophozoites/mL (counted using a hemocytometer), 3.33 x 104 CFU/mL for C. albicans, and either 5.53 x 106 CFU/mL (for co-culture with the ATCC isolate) or 5.53 x 107 CFU/mL (for co-culture with a fresh clinical isolate) for L. crispatus. The cell densities of C. albicans and L. crispatus were quantified as colony-forming units (CFU) on selective agar. The incubation period for co-culture, ensuring optimal growth of all microorganisms, was 24 hours. In co-culture, L. crispatus at both tested densities acidified the medium. The co-culture system demonstrated lower MIC values for metronidazole (50 mu M in the ATCC isolate co-culture and 25 mu M with the fresh clinical isolate) and lower MFC values for fluconazole (6.25 mu M), compared to monocultures of T. vaginalis (100 mu M) and C. albicans (12.50 mu M). Furthermore, the triple co-culture increased the cytotoxicity to vaginal cell and erythrocytes for the ATCC isolate while significantly inhibited both biofilm formation and metabolic activity of C. albicans (by up to 92% and 90%, respectively), as well as its yeast-to-hyphae transition (by up to 70%). SEM analyses highlighted the morphological differences among T. vaginalis, C. albicans, and L. crispatus, including isolate-specific size variations in the protozoan. These findings suggest that this in vitro co-culture system is a valuable tool for evaluating the antimicrobial efficacy of novel compounds against vaginitis pathogens and for studying interactions within the vaginal microenvironment.

Trichomoniasis is the most common non-viral sexually transmitted infection (STI) in the world. The estimated global prevalence in 2016 was 156 million adults aged 15–49. However, these data are underestimated, since the most used diagnostic method is the wet mount, which has low sensitivity, the information regarding the estimated duration of infection is limited and there is evidence of undiagnosed asymptomatic cases in both sexes. Currently 80% of cases—including both sexes—are asymptomatic, which makes the disease silent and chronic in course, leading to complications. The aim of this review was to discuss the diagnostic methods for T. vaginalis detection that are currently available and applicable in the clinical laboratory routine. Overall, nucleic acid amplification techniques are the best option for T. vaginalis detection, with higher sensitivity and specificity than other tests. Although these techniques present higher cost, their implementation should be supported to ensure correct trichomoniasis diagnosis and treatment beyond contributing to questions on epidemiology and control.

The failures in Trichomonas vaginalis (TV) infection diagnosis leave more than half of cases unidentified. In this report, urine and vaginal discharge samples were analyzed by wet mount, culture examination, and real-time PCR by Allplex™ (Seegene®) kit, in a population assisted by the Brazilian Public Health System. From 747 samples, 2.81

Trichomonas vaginalis is responsible for 156 million new cases per year worldwide. When present asymptomatically, the parasite can lead to serious complications, such as development of cervical and prostate cancer. As infection increases the acquisition and transmission of HIV, the control of trichomoniasis represents an important niche for the discovery and development of new antiparasitic molecules. This urogenital parasite synthesizes several molecules that allow the establishment and pathogenesis of infection. Among them, peptidases occupy key roles as virulence factors, and the inhibition of these enzymes has become an important mechanism for modulating pathogenesis. Based on these premises, our group recently reported the potent anti-T. vaginalis action of the metal-based complex [Cu(phendione)3](ClO4)2.4H2O (Cu-phendione). In the present study, we evaluated the influence of Cu-phendione on the modulation of proteolytic activities produced by T. vaginalis by biochemical and molecular approaches. Cu-phendione showed strong inhibitory potential against T. vaginalis peptidases, especially cysteine- and metallo-type peptidases. The latter revealed a more prominent effect at both the post-transcriptional and post-translational levels. Molecular Docking analysis confirmed the interaction of Cu-phendione, with high binding energy (−9.7 and −10.7 kcal·mol−1, respectively) at the active site of both TvMP50 and TvGP63 metallopeptidases. In addition, Cu-phendione significantly reduced trophozoite-mediated cytolysis in human vaginal (HMVII) and monkey kidney (VERO) epithelial cell lineages. These results highlight the antiparasitic potential of Cu-phendione by interaction with important T. vaginalis virulence factors.

The disbalance of vaginal eubiotic microbiota can lead to overgrowth of Candida species and bacteria responsible for aerobic vaginitis, activating inflammatory pathways. The presence of Trichomonas vaginalis, a sexually transmitted protozoan pathogen, can be a predisposing factor for disordering the growth of bacterial/fungal pathogenic species due to the increase in pH and reduction of eubiotic microbiota. Herein, we evaluated the effects of the potent trichomonacidal compound, copper(II)-1,10-phenanthroline-5,6-dione (Cu-phendione), against pathogens responsible for candidiasis and aerobic vaginitis. Cu-phendione showed antimicrobial activity against Candida albicans, non-albicans Candida species (C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis) and Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus, Enterococcus faecalis, and Streptococcus agalactiae) bacteria. Moreover, Cu-phendione was able to interfere with the fungal biofilm formation. These results highlight the antimicrobial potential of Cu-phendione against bacterial and fungal strains of vaginitis-causing infectious agents.

This article provides a comprehensive review of several subclasses of metallo-type peptidases expressed by the main clinically relevant protozoa, including Plasmodium spp., Toxoplasma gondii, Cryptosporidium spp., Leishmania spp., Trypanosoma spp., Entamoeba histolytica, Giardia duodenalis, and Trichomonas vaginalis. These species comprise a diverse group of unicellular eukaryotic microorganisms responsible for widespread and severe human infections. Metallopeptidases, defined as hydrolases with activity mediated by divalent metal cation, play important roles in the induction and maintenance of parasitic infections. In this context, metallopeptidases can be considered veritable virulence factors in protozoa with direct/indirect participation in several key pathophysiological processes, including adherence, invasion, evasion, excystation, central metabolism, nutrition, growth, proliferation, and differentiation. Indeed, metallopeptidases have become an important and valid target to search for new compounds with chemotherapeutic purposes. The present review aims to gather updates regarding metallopeptidase subclasses, exploring their participation in protozoa virulence as well as investigating the similarity of peptidase sequences through bioinformatic techniques in order to discover clusters of great relevance for the development of new broad antiparasitic molecules.

Trichomonas vaginalis, a flagellated and anaerobic protozoan, is a causative agent of trichomoniasis. This disease is among the world's most common non-viral sexually transmitted infection. A single class drug, nitroimidazoles, is currently available for the trichomoniasis treatment. However, resistant isolates have been identified from unsuccessfully treated patients. Thus, there is a great challenge for a discovery of innovative anti-T. vaginalis agents. As part of our ongoing search for antiprotozoal chalcones, we designed and synthesized a series of 21 phenolic chalcones, which were evaluated against T. vaginalis trophozoites. Structure-activity relationship indicated hydroxyl group plays a role key in antiprotozoal activity. 4 '-Hydroxychalcone (4HC) was the most active compound (IC50 = 27.5 mu M) and selected for detailed bioassays. In vitro and in vivo evaluations demonstrated 4HC was not toxic against human erythrocytes and Galleria mellonella larvae. Trophozoites of T. vaginalis were treated with 4HC and did not present significant reactive oxygen species (ROS) accumulation. However, compound 4HC was able to increase ROS accumulation in neutrophils coincubated with T. vaginalis. qRT-PCR Experiments indicated that 4HC did not affect the expression of pyruvate:ferredoxin oxidoreductase (PFOR) and beta-tubulin genes. In silico simulations, using purine nucleoside phosphorylase of T. vaginalis (TvPNP), corroborated 4HC as a promising ligand. Compound 4HC was able to establish interactions with residues D21, G20, M180, R28, R87 and T90 through hydrophobic interactions, pi-donor hydrogen bond and hydrogen bonds. Altogether, these results open new avenues for phenolic chalcones to combat trichomoniasis, a parasitic neglected infection.

Trichomoniasis is a neglected, parasitic, sexually transmitted infection. Resistance to the only approved drugs is increasing worldwide, leaving millions of people without alternative medications. Thus, the search for new therapeutic options against this infection is necessary. Previously, our group reported that 1,10-phenanthroline-5,6-dione (phendione) and its silver(I) and copper (II) complexes (abbreviated as Ag-phendione and Cu-phendione, respectively) presented activity against the amitochondriate parasite T. vaginalis, with Cu-phendione being the most effective (IC50 = 0.84 μM). Methods: qRT-PCR, SEM, flow cytometry. The current study on the effects of Cu-phendione on the antioxidant metabolism of T. vaginalis by qRT-PCR revealed that the complex causes a decrease in the relative expression of mRNA of NADH oxidase, flavin reductase, superoxide dismutase, peroxiredoxin, iron-sulfur flavoprotein, rubrerythrin and osmotically inducible proteins. In contrast, the mRNA expression of flavodiiron protein was increased. Detoxification-related enzymes were downregulated, impairing oxygen metabolism in trophozoites and triggering a subsequent accumulation of the superoxide anion. Although no DNA fragmentation was observed, the treatment of parasites with Cu-phendione led to a significant reduction in cell size and a concomitant increase in granularity. The complex promoted phosphatidylserine exposure at the plasma membrane (as judged by Annexin V binding) and propidium iodide was unable to passively permeate the parasites. All of these outcomes are classical hallmarks of cell death by apoptosis. In essence, the trichomonacidal effect of Cu-phendione operates through redox homeostasis imbalance, which is a mode of action that is quite distinct from that caused by metronidazole.

The multistep translational science behind new drugs comprehends the entire process through laboratory, clinical, and community observations turned into health interventions. The development of new drug options from discovering targets and leading compounds in basic research for implementing therapeutic guidelines contributes to the emergence of health policies essential for infection control. This review updates the translational research in the scenario of the most common non-viral sexually transmitted infection (STI), trichomoniasis. Paradoxically to its high occurrence, it is considered neglected since notification is not mandatory. It turns into a stable disease with health complications, and receives little emphasis from public health programs to control STI. Although related to curable STIs, the current drugs, metronidazole and tinidazole, present therapeutic failures. The need for new options to treat trichomoniasis is established by basic research studies and patents revealing novel synthetic compounds and natural products presenting anti-Trichomonas vaginalis activities, mainly based on in vitro findings. Clinical trials are still focused on new routes of administration for conventional drugs. In addition, nanotechnology approaches are in their infancy, shedding light on potential possibilities for creating more effective, targeted, and safe delivery systems. Overall, the novel proposed approaches need, in addition to pharmaceutical development and efficacy assessments, to ensure that the quality requirements for their use as medicines are met. It is essential to overcome these issues to cross the “Death Valley” of drug discovery and to advance in the translational science criteria in the trichomoniasis drug development field.

Trichomoniasis is the most common nonviral sexually transmitted infection in the world, but its available therapies present low efficacy and high toxicity. Diphenyl diselenide (PhSe2) is a pharmacologically active organic selenium compound; however, its clinical use is hindered by its lipophilicity and toxicity. Nanocarriers are an interesting approach to overcome the limitations associated with this compound. This study designed and evaluated a vaginal hydrogel containing PhSe2-loaded Eudragit® RS100 and coconut oil nanocapsules for the treatment of trichomoniasis. Nanocapsules presented particle sizes in the nanometric range, positive zeta potential, a compound content close to the theoretical value, and high encapsulation efficiency. The nanoencapsulation maintained the anti-Trichomonas vaginalis action of the compound while improving the scavenger action in a DPPH assay. The hydrogels were prepared by thickening nanocapsule suspensions with locust bean gum (3%). The semisolids maintained the nanometric size of the particles and the PhSe2 content at around the initial concentration (1.0 mg/g). They also displayed non-Newtonian pseudo-plastic behavior and a highly mucoadhesive property. The chorioallantoic membrane method indicated the absence of hemorrhage, coagulation, or lysis. The compound, from both non-encapsulated and nano-based hydrogel delivery systems, remained on the surface of the bovine vaginal mucosa. Therefore, the formulations displayed the intended properties and could be a promising alternative for the treatment of trichomoniasis.

Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and it may have serious consequences, especially for women. Currently, 5-nitroimidazole drugs are the treatment of choice for trichomoniasis, although presenting adverse effects and reported cases of drug resistance. Metabolites isolated from marine fungi have attracted considerable attention due to their unique chemical structures with diverse biological activities, including antiprotozoal activity. In this study, we showed the anti-Trichomonas vaginalis activity of fractions obtained from marine fungi and the chemical composition of the most active fraction was determined. Ethyl acetate fractions of the fungus Aspergillus niger (EAE03) and Trichoderma harzianum/Hypocrea lixii complex (EAE09) were active against T. vaginalis. These samples, EAE03 and EAE09, were also effective against the fresh clinical isolate metronidazole-resistant TV-LACM2R, presenting MIC values of 2.0 mg/mL and 1.0 mg/mL, respectively. The same MIC values were found against ATCC 30,236 T. vaginalis isolate. In vitro cytotoxicity revealed only the fraction named EAE03 with no cytotoxic effect; however, the active fractions did not promote a significant hemolytic effect after 1-h incubation. Already, the in vivo toxicity evaluation using Galleria mellonella larvae demonstrated that none of the tested samples caused a reduction in animal survival. The fraction EAE03 was followed for purification steps and analyzed by LC-DAD-MS. Eleven compounds were annotated, including butyrolactone, butanolide, and atromentin. Overall, the range of activities reported confirms the potential of marine fungi to produce bioactive molecules.

Trichomoniasis is the most common non-viral sexually transmitted infection (STI) in the world caused by Trichomonas vaginalis. Failures in the treatment with the 5-nitroimidazole class including parasite resistance to metronidazole elicit new alternatives. Marine natural products are sources of several relevant molecules, presenting a variety of metabolites with numerous biological activities. In this work, we evaluated the anti-T. vaginalis activity of fungi associated with marine invertebrates by mass spectrometry-based metabolomics approaches. After screening of six marine fungi, extract from Penicillium citrinum FMPV 15 has shown to be 100

Trichomoniasis is a neglected parasitic infection, with no oral therapeutic alternatives to overcome the pitfalls of currently approved drugs. In this context, the search for new anti-Trichomonas vaginalis drugs is imperative. Here we report the selective anti-T. vaginalis activity of a substituted 8-hydroxyquinoline-5-sulfonamide derivative. Six different derivatives were evaluated for anti-T. vaginalis. In vitro and in vivo toxicity methods, association with metal ions, and investigation on the mechanism of action were performed with the most active derivative, PH 152. Cytotoxicity assays showed selectivity for the parasite and the low toxicity was confirmed in G. mellonella larvae model. The mode of action is related to iron chelation by disrupting Fe-S clusters-dependent enzyme activities in the parasite. Proteomic analysis indicated inhibition of metallopeptidases related to T. vaginalis virulence mechanisms and metabolic pathways. PH 152 presented selective trichomonacidal activity through multitarget action.

Trichomonas vaginalis is an amitochondriate protozoan and the agent of human trichomoniasis, the most prevalent non-viral sexually transmitted infection (STI) in the world. In this study we showed that 2,4-diamine-quinazoline derivative compound (PH100) kills T. vaginalis. PH100 showed activity against fresh clinical and American Type Culture Collection (ATCC) T. vaginalis isolates with no cytotoxicity against cells (HMVI, 3T3-C1 and VERO) and erythrocytes. In addition, PH100 showed synergistic action with metronidazole, indicating that these compounds act by different mechanisms. When investigating the mechanism of action of PH100 to ATCC 30236, apoptosis-like characteristics were observed, such as phosphatidylserine exposure, membrane alterations, and modulation of gene expression and activity of peptidases related to apoptosis. The apoptosis-like cell death features were not observed for the fresh clinical isolate treated with PH100 revealing distinct profiles. Our data revealed the heterogeneity among T. vaginalis isolates and contribute with the understanding of mechanisms of cell death in pathogenic eukaryotic organisms without mitochondria.

Trichomonas vaginalis causes trichomoniasis, a nonviral sexually transmitted infection with a high prevalence worldwide. Oral metronidazole is the drug of choice for the treatment of this disease, although high levels of T. vaginalis resistance to this agent are well documented in the literature. This study describes the anti- T. vaginalis activity of an optimized coumarin-rich extract from Pterocaulon balansae . Optimization was performed to maximize extraction of total coumarins by means of a 3-level Box-Behnken design, evaluating the effect of three factors: extraction time, plant:solvent ratio, and ethanol concentration. Optimum conditions were found to be 5h extraction time and a plant:solvent ratio of 1% (w/v) and 60% (v/v) ethanol, which resulted in approximately 30mg of total coumarins/g of dry plant. The coumarin-enriched extract exhibited a minimum inhibitory concentration of 30 mu g/mL and an IC (50) of 3.2 mu g/mL against T. vaginalis , a low cytotoxicity, and a high selectivity index (18 for vaginal epithelial cells and 16 for erythrocytes). The coumarins permeation/retention profile through porcine vaginal mucosa was evaluated in Franz-type diffusion cells. After 8h of kinetics, coumarins were detected in the tissue (4.93 mu g/g) without detecting them in the receptor compartment. A significant increase of coumarins in the mucosa layers (8.18 mu g/g) and receptor compartment (0.26 mu g/g) was detected when a T. vaginalis suspension (2x10 (5) trophozoites/mL) was previously added onto the mucosa. No alterations were visualized in the stratified squamous non-keratinized epithelium of the porcine vaginal mucosa after contact with the extract. Overall, these results suggest that the P. balansae coumarin-rich extract may have potential as a treatment for trichomoniasis.

Iridoids are secondary metabolites with several biological activities. They are often found in species of the genus Tabebuia Gomes ex A.P. de Candolle. Tabebuia aurea (Silva Manso) Benth. & Hook. F. ex S. Moore, Bignoniaceae, is used to treat snake bites in traditional medicine. This study aimed to isolate the specioside - an the iridoid glycoside - from T. aurea, as well as investigate its potential biological properties, including anti-inflammatory, antibacterial, antibiofilm, cytotoxic, anti-Trichomonas vaginalis and antitrypanosomal activities. Specioside inhibited leucocyte recruitment into the peritoneal cavity in mice injected with carrageenan, data that demonstrated its anti-inflammatory potential. However, the additional evaluated biological properties were negligible.

Trichomonas vaginalis infection is the STI most common worldwide. Indole-3-carbinol (I3C) is a phytochemical presenting promising biological activities. In this study, design, formulation, and evaluation of a vaginal hy- drogel containing I3C-loaded nanocapsules for the treatment of trichomoniasis have been investigated. Nanocapsules of Eudragit (R) RS100 and rosehip oil containing I3C (NC-I3C) were prepared by interfacial de- position of preformed polymer method. In vitro evaluations showed that free I3C (IC50 = 3.36 mu g/mL) was able to reduce the trophozoites viability at higher concentrations (3.13 and 6.25 mu g/mL), while nanoencapsulation (IC50 = 2.09 mu g/mL) reduced the viability at all concentrations evaluated. Comparing free and nanoencapsu- lated I3C, we observe that nanoencapsulation improved anti - T. vaginalis activity. In order to obtain a formulation for vaginal administration, hydrogels (HG-NC-I3C) were prepared by thickening the NC-I3C with gellan gum. HG-NC-I3C presented particle size below 195 nm, low polydispersity index (<0.2), I3C content = 0.50 +/- 0.01 mg/g, pH = 7.05, non -Newtonian pseudoplastic flow behavior and exhibited mucoadhesion to cow's vaginal mucosa. Evaluation of irritation potential by chorioallantoic membrane method indicated that the formulations are considered non -irritating. Besides that, permeation through the cow's vaginal mucosa showed that na- noencapsulation promoted I3C controlled release. This way, the developed HG-NC-I3C can be considered a promising approach for trichomoniasis treatment through vaginal administration.

Female genital tract infections have a high incidence among different age groups and represent an important impact on public health. Among them, vaginitis refers to inflammation of the vulva and/or vagina due to the presence of pathogens that cause trichomoniasis, bacterial vaginosis, and vulvovaginal candidiasis. Several discomforts are associated with these infections, as well as pregnancy complications and the facilitation of HIV transmission and acquisition. The increasing resistance of microorganisms to drugs used in therapy is remarkable, since women report the recurrence of these infections and associated comorbidities. Different resistant mechanisms already described for the drugs used in the therapy against Trichomonas vaginalis, Candida spp., and Gardnerella vaginalis, as well as aspects related to pathogenesis and treatment, are discussed in this review. This study aims to contribute to drug design, avoiding therapy ineffectiveness due to drug resistance. Effective alternative therapies to treat vaginitis will reduce the recurrence of infections and, consequently, the high costs generated in the health system, improving women's well-being.

Poincianella (Caesalpinia) microphylla fractions were analyzed by LC-DAD-MS and by statistical tools to determine the possible bioactive compounds against T. vaginalis. Tannins enriched-fractions toxicity (M5 and M10) were analyzed in in vitro against human red cells and in in vivo model of Galleria mellonella. Twenty-six compounds were detected from the P. microphylla fractions. The main compounds identified were hydrolyzable tannins (gallotanins and ellagitannis), such as O-digalloyl hexoside, O-digalloyl HHDP -hexoside, tri-O-galloyl HHDP-hexoside, O-galloyl HHDP-DHHDP-hexoside and their isomers. In addition, procyanidin dimer, epicatechin, ellagic acid and O-(digalloyl) quinic acid were also identified. Based on univariate statistical analyses, stronger correlations with the anti-T. vaginalis properties were observed for the compounds 7 (O-galloyl HHDP-DHHDP-hexoside - Geraniin isomer), 3 (O-digalloyl HHDP -hexoside - mallotinic acid), 2 (O-digalloyl) quinic acid), 1 (O-digalloyl hexoside) and 9 (unknown). Tannins enriched-fractions (M5 and M10) presented anti-Trichomonas activity (IC50 70.41 µg/mL and 142.1 µg/mL, respectively) and no toxicity in the in vivo model of G. mellonella. This innovative approach allowed us to identify likely bioactive compounds in the extracts, although the mechanism(s) underlying anti-trichomonal activity encompass a complex trait.