In silico study to explore the mechanism of Toxoplasma-induced inflammation and target therapy based on sero and salivary Toxoplasma.

We aimed to assess salivary and seroprevalence of Toxoplasma immunoglobulins in risky populations and evaluate drug docking targeting TgERP. A cross-sectional study was conducted in Alexandria University hospitals' outpatient clinics. 192 participants were enrolled from September 2022 to November 2023. Anti-Toxoplasma IgG and IgM were determined in serum and saliva by ELISA. An in-Silico study examined TgERP's protein-protein interactions (PPIs) with pro-inflammatory cytokine receptors, anti-inflammatory cytokine, cell cycle progression regulatory proteins, a proliferation marker, and nuclear envelope integrity-related protein Lamin B1. Our findings revealed that anti-T. gondii IgG were detected in serum (66.1%) and saliva (54.7%), with 2.1% of both samples were positive for IgM. Salivary IgG had 75.59% sensitivity, 86.15% specificity, 91.40% PPV, 64.40% NPP, 79.17% accuracy and fair agreement with serum IgG. On the other hand, the sensitivity, specificity, PPV, NPV, and accuracy in detecting salivary IgM were 75.0%, 99.47%, 75.0%, 99.47%, and 98.96%. AUC 0.859 indicates good discriminatory power. Examined synthetic drugs and natural products can target specific amino acids residues of TgERP that lie at the same binding interface with LB1 and Ki67, subsequently, hindering their interaction. Hence, salivary samples can be a promising diagnostic approach. The studied drugs can counteract the pro-inflammatory action of TgERP.

Bicyclic Pyrrolidine Inhibitors of Toxoplasma gondii Phenylalanine t-RNA Synthetase with Antiparasitic Potency In Vitro and Brain Exposure.

Previous studies have shown that bicyclic azetidines are potent and selective inhibitors of apicomplexan phenylalanine tRNA synthetase (PheRS), leading to parasite growth inhibition in vitro and in vivo, including in models of Toxoplasma infection. Despite these useful properties, additional optimization is required for the development of efficacious treatments of toxoplasmosis from this inhibitor series, in particular, to achieve optimal exposure in the brain. Here, we describe a series of PheRS inhibitors built on a new bicyclic pyrrolidine core scaffold designed to retain the exit-vector geometry of the isomeric bicyclic azetidine core scaffold while offering avenues to sample diverse chemical space. Relative to the parent series, bicyclic pyrrolidines retain reasonable potency and target selectivity for parasite PheRS vs host. Further structure-activity relationship studies revealed that the introduction of aliphatic groups improved potency and ADME and PK properties, including brain exposure. The identification of this new scaffold provides potential opportunities to extend the analogue series to further improve selectivity and potency and ultimately deliver a novel, efficacious treatment of toxoplasmosis.

Lipid metabolism: the potential targets for toxoplasmosis treatment.

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii (T. gondii). The current treatment for toxoplasmosis remains constrained due to the absence of pharmaceutical interventions. Thus, the pursuit of more efficient targets is of great importance. Lipid metabolism in T. gondii, including fatty acid metabolism, phospholipid metabolism, and neutral lipid metabolism, assumes a crucial function in T. gondii because those pathways are largely involved in the formation of the membranous structure and cellular processes such as division, invasion, egress, replication, and apoptosis. The inhibitors of T. gondii's lipid metabolism can directly lead to the disturbance of various lipid component levels and serious destruction of membrane structure, ultimately leading to the death of the parasites. In this review, the specific lipid metabolism pathways, correlative enzymes, and inhibitors of lipid metabolism of T. gondii are elaborated in detail to generate novel ideas for the development of anti-T. gondii drugs that target the parasites' lipid metabolism.

In Vitro Anti-Toxoplasma Activity of Extracts Obtained from Tabebuia rosea and Tabebuia chrysantha: The Role of ß-Amyrin.

Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii that is highly prevalent worldwide. Although the infection is asymptomatic in immunocompetent individuals, it severely affects immunocompromised individuals, causing conditions such as encephalitis, myocarditis, or pneumonitis. The limited therapeutic efficacy of drugs currently used to treat toxoplasmosis has prompted the search for new therapeutic alternatives. The aim of this study was to determine the anti-Toxoplasma activity of extracts obtained from two species of the genus Tabebuia. Twenty-six extracts, 12 obtained from Tabebuia chrysantha and 14 from Tabebuia rosea, were evaluated by a colorimetric technique using the RH strain of T. gondii that expresses ß-galactosidase. Additionally, the activity of the promising extracts and their active compounds was evaluated by flow cytometry. ß-amyrin was isolated from the chloroform extract obtained from the leaves of T. rosea and displayed important anti-Toxoplasma activity. The results show that natural products are an important source of new molecules with considerable biological and/or pharmacological activity.

Effect of the mitochondrial uncoupling agent BAM15 against the Toxoplasma gondii RH strain and Prugniaud strain.

BACKGROUND: Toxoplasmosis is a zoonotic disease caused by the infection of the protozoa Toxoplasma gondii (T. gondii), and safe and effective therapeutic drugs are lacking. Mitochondria, is an important organelle that maintains T. gondii survival, however, drugs targeting mitochondria are lacking. METHODS: The cytotoxicity of BAM15 was detected by CCK-8 and the in vitro effects of BAM15 was detected by qPCR, plaque assay and flow cytometry. Furthermore, the ultrastructural changes of T. gondii after BAM15 treatment were observed by transmission electron microscopy, and further the mitochondrial membrane potential (ΔΨm), ATP level and reactive oxygen species (ROS) of T. gondii after BAM15 treatment were detected. The pharmacokinetic experiments and in vivo infection assays were performed in mice to determine the in vivo effect of BAM15. RESULTS: BAM15 had excellent anti-T. gondii activity in vitro and in vivo with an EC50 value of 1.25 µM, while the IC50 of BAM15 in Vero cells was 27.07 µM. Notably, BAM15 significantly inhibited proliferation activity of T. gondii RH strain and Prugniaud strain (PRU), caused T. gondii death. Furthermore, BAM15 treatment induced T. gondii mitochondrial vacuolation and autolysis by TEM. Moreover, the decrease in ΔΨm and ATP level, as well as the increase in ROS production further confirmed the changes CONCLUSIONS: Our study identifies a useful T. gondii mitochondrial inhibitor, which may also serve as a leading molecule to develop therapeutic mitochondrial inhibitors in toxoplasmosis.'

Anti-Toxoplasma gondii effect of tylosin in vitro and in vivo.

BACKGROUND: Toxoplasma gondii is an important protozoan pathogen with medical and veterinary importance worldwide. Drugs currently used for treatment of toxoplasmosis are less effective and sometimes cause serious side effects. There is an urgent need for the development of more effective drugs with relatively low toxicity. METHODS: The effect of tylosin on the viability of host cells was measured using CCK8 assays. To assess the inhibition of tylosin on T. gondii proliferation, a real-time PCR targeting the B1 gene was developed for T. gondii detection and quantification. Total RNA was extracted from parasites treated with tylosin and then subjected to transcriptome analysis by RNA sequencing (RNA-seq). Finally, murine infection models of toxoplasmosis were used to evaluate the protective efficacy of tylosin against T. gondii virulent RH strain or avirulent ME49 strain. RESULTS: We found that tylosin displayed low host toxicity, and its 50% inhibitory concentration was 175.3 µM. Tylsoin also inhibited intracellular T. gondii tachyzoite proliferation, with a 50% effective concentration of 9.759 µM. Transcriptome analysis showed that tylosin remarkably perturbed the gene expression of T. gondii, and genes involved in "ribosome biogenesis (GO:0042254)" and "ribosome (GO:0005840)" were significantly dys-regulated. In a murine model, tylosin treatment alone (100 mg/kg, i.p.) or in combination with sulfadiazine sodium (200 mg/kg, i.g.) significantly prolonged the survival time and raised the survival rate of animals infected with T. gondii virulent RH or avirulent ME49 strain. Meanwhile, treatment with tylosin significantly decreased the parasite burdens in multiple organs and decreased the spleen index of mice with acute toxoplasmosis. CONCLUSIONS: Our findings suggest that tylosin exhibited potency against T. gondii both in vitro and in vivo, which offers promise for treatment of human toxoplasmosis.

Anti-Toxoplasma In Vitro and In Vivo Activity of Pyrus boissieriana Arbutin-Rich Fraction.

PURPOSE: Pyrus boissieriana is a rich source of arbutin and has been used in herbal medicine to treat infectious diseases. This study aimed to investigate the effect of the arbutin-rich fraction of Pyrus boissieriana aerial parts on Toxoplasma gondii In Vitro and In Vivo. METHODS: An arbutin-rich fraction of P. boissieriana was prepared beforehand. Flow cytometry was used to evaluate the effect of different concentrations (1-512 µg/ml) of the P. boissieriana arbutin-rich fraction on Toxoplasma tachyzoites (RH strain). The cytotoxicity of the concentrations on the macrophage J774 cell line was also investigated by MTT assay. For In Vivo investigation, 4-6-week-old female mice infected with the RH strain of T. gondii were treated with different doses (16, 32, 64, 256, and 512 mg/kg) of the fraction using gavage. RESULTS: The highest and lowest lethality of the tachyzoites were 89.6% and 25.9% related to the concentrations of 512 µg/ml and 1 µg/ml, respectively, with an IC50 value of 18.1 µg/ml ± 0.37. The cytotoxicity test showed an IC50 value of 984.3 µg/ml ± 0.76 after 48 h incubation. The mean survival of mice at the lowest treated dose (16 mg/kg) was 6.6 days, and it was 15 days at the highest dose (512 mg/kg). The concentrations of 512, 256, 128, and 64 mg/kg of the fraction compared to the negative control (6.2 days mean survival) significantly increased the survival time of mice (P < 0.001, P = 0.009, P = 0.018, and P = 0.021, respectively). CONCLUSION: The results showed that the arbutin-rich fraction of P. boissieriana is effective against T. gondii In Vitro and In Vivo and may be a reliable alternative to conventional treatment for toxoplasmosis, although further studies are necessary.

In vitro screening technologies for the discovery and development of novel drugs against Toxoplasma gondii.

INTRODUCTION: Toxoplasmosis constitutes a challenge for public health, animal production and welfare. Since more than 60 years, only a limited panel of drugs has been in use for clinical applications. AREAS COVERED: Herein, the authors describe the methodology and the results of library screening approaches to identify inhibitors of Toxoplasma gondii and related strains. The authors then provide the reader with their expert perspectives for the future. EXPERT OPINION: Various library screening projects, in particular those using reporter strains, have led to the identification of numerous compounds with good efficacy and specificity in vitro. However, only few compounds are effective in suitable animal models such as rodents. Whereas no novel compound has cleared the hurdle to applications in humans, the few compounds with known indication and application profiles in human patients are of interest for further investigations. Taken together, drug repurposing as well as high-throughput screening of novel compound libraries may shorten the way to novel drugs against toxoplasmosis.

Protective effect of arctiin against Toxoplasma gondii HSP70-induced allergic acute liver injury by disrupting the TLR4-mediated activation of cytosolic phospholipase A2 and platelet-activating factor.

Toxoplasma gondii (T. gondii)-derived heat shock protein 70 (T.g.HSP70) is a toxic protein that downregulates host defense responses against T. gondii infection. T.g.HSP70 was proven to induce fatal anaphylaxis in T. gondii infected mice through cytosolic phospholipase A2 (cPLA2) activated-platelet-activating factor (PAF) production via Toll-like receptor 4 (TLR4)-mediated signaling. In this study, we investigated the effect of arctiin (ARC; a major lignan compound of Fructus arctii) on allergic liver injury using T.g.HSP70-stimulated murine liver cell line (NCTC 1469) and a mouse model of T. gondii infection. Localized surface plasmon resonance, ELISA, western blotting, co-immunoprecipitation, and immunofluorescence were used to investigate the underlying mechanisms of action of ARC on T. gondii-induced allergic acute liver injury. The results showed that ARC suppressed the T.g.HSP70-induced allergic liver injury in a dose-dependent manner. ARC could directly bind to T.g.HSP70 or TLR4, interfering with the interaction between these two factors, and inhibiting activation of the TLR4/mitogen-activated protein kinase/nuclear factor-kappa B signaling, thereby inhibiting the overproduction of cPLA2, PAF, and interferon-γ. This result suggested that ARC ameliorates T.g.HSP70-induced allergic acute liver injury by disrupting the TLR4-mediated activation of inflammatory mediators, providing a theoretical basis for ARC therapy to improve T.g.HSP70-induced allergic liver injury.

Guidelines for the management of Toxoplasma gondii infection and disease in patients with haematological malignancies and after haematopoietic stem-cell transplantation: guidelines from the 9th European Conference on Infections in Leukaemia, 2022.

Patients with haematological malignancies might develop life-threatening toxoplasmosis, especially after allogeneic haematopoietic stem-cell transplantation (HSCT). Reactivation of latent cysts is the primary mechanism of toxoplasmosis following HSCT; hence, patients at high risk are those who were seropositive before transplantation. The lack of trimethoprim-sulfamethoxazole prophylaxis and various immune status parameters of the patient are other associated risk factors. The mortality of toxoplasma disease-eg, with organ involvement-can be particularly high in this setting. We have developed guidelines for managing toxoplasmosis in haematology patients, through a literature review and consultation with experts. In allogeneic HSCT recipients seropositive for Toxoplasma gondii before transplant, because T gondii infection mostly precedes toxoplasma disease, we propose weekly blood screening by use of quantitative PCR (qPCR) to identify infection early as a pre-emptive strategy. As trimethoprim-sulfamethoxazole prophylaxis might fail, prophylaxis and qPCR screening should be combined. However, PCR in blood can be negative even in toxoplasma disease. The duration of prophylaxis should be a least 6 months and extended during treatment-induced immunosuppression or severe CD4 lymphopenia. If a positive qPCR test occurs, treatment with trimethoprim-sulfamethoxazole, pyrimethamine-sulfadiazine, or pyrimethamine-clindamycin should be started, and a new sample taken. If the second qPCR test is negative, clinical judgement is recommended to either continue or stop therapy and restart prophylaxis. Therapy must be continued until a minimum of two negative PCRs for infection, or for at least 6 weeks for disease. The pre-emptive approach is not indicated in seronegative HSCT recipients, after autologous transplantation, or in non-transplant haematology patients, but PCR should be performed with a high level of clinical suspicion.

Triclabendazole and clofazimine reduce replication and spermine uptake in vitro in Toxoplasma gondii.

Toxoplasmosis is a worldwide zoonosis caused by the protozoan parasite Toxoplasma gondii. Although this infection is generally asymptomatic in immunocompetent individuals, it can cause serious clinical manifestations in newborns with congenital infection or in immunocompromised patients. As current treatments are not always well tolerated, there is an urgent need to find new drugs against human toxoplasmosis. Drug repurposing has gained considerable momentum in the last decade and is a particularly attractive approach for the search of therapeutic alternatives to treat rare and neglected diseases. Thus, in this study, we investigated the antiproliferative effect of several repurposed drugs. Of these, clofazimine and triclabendazole displayed a higher selectivity against T. gondii, affecting its replication. Furthermore, both compounds inhibited spermine incorporation into the parasite, which is necessary for the formation of other polyamines. The data reported here indicate that clofazimine and triclabendazole could be used for the treatment of human toxoplasmosis and confirms that drug repurposing is an excellent strategy to find new therapeutic targets of intervention.

Mitochondrial dysfunction induced by bedaquiline as an anti-Toxoplasma alternative.

Toxoplasma gondii is a zoonotic parasite that infects one-third of the world's population and nearly all warm-blooded animals. Due to the complexity of T. gondii's life cycle, available treatment options have limited efficacy. Thus, there is an urgent need to develop new compounds or repurpose existing drugs with potent anti-Toxoplasma activity. This study demonstrates that bedaquiline (BDQ), an FDA-approved diarylquinoline antimycobacterial drug for the treatment of tuberculosis, potently inhibits the tachyzoites of T. gondii. At a safe concentration, BDQ displayed a dose-dependent inhibition on T. gondii growth with a half-maximal effective concentration (EC50) of 4.95 µM. Treatment with BDQ significantly suppressed the proliferation of T. gondii tachyzoites in the host cell, while the invasion ability of the parasite was not affected. BDQ incubation shrunk the mitochondrial structure and decreased the mitochondrial membrane potential and ATP level of T. gondii parasites. In addition, BDQ induced elevated ROS and led to autophagy in the parasite. By transcriptomic analysis, we found that oxidative phosphorylation pathway genes were significantly disturbed by BDQ-treated parasites. More importantly, BDQ significantly reduces brain cysts for the chronically infected mice. These results suggest that BDQ has potent anti-T. gondii activity and may impair its mitochondrial function by affecting proton transport. This study provides bedaquiline as a potential alternative drug for the treatment of toxoplasmosis, and our findings may facilitate the development of new effective drugs for the treatment of toxoplasmosis.

Single and combination treatment of Toxoplasma gondii infections with a bumped kinase inhibitor and artemisone in vitro and with artemiside in experimentally infected mice.

In previous studies, the artemisinin derivatives artemisone, its pro-drug artemiside and the bumped-kinase inhibitor BKI-1748 were effective against T. gondii via different modes of action. This suggests that they may act synergistically resulting in improved efficacies in vitro and in vivo. To test this hypothesis, the compounds were applied alone and in combination to T. gondii infected human fibroblast host cells in order to determine their inhibition constants and effects on cellular ultrastructure. In addition, the efficacy of either single- or combined treatments were assessed in an acute TgShSp1-oocyst infection model based on CD1 outbred mice. Whereas the IC50 of the compounds in combination (42 nM) was close to the IC50 of BKI-1748 alone (46 nM) and half of the IC50 of artemisone alone (92 nM), the IC90 of the combination was half of the values found with the single compounds (138 nM vs. ca. 270 nM). Another indication for synergistic effects in vitro were distinct alterations of the cellular ultrastructure of tachyzoites observed in combination, but not with the single compounds. These promising results could not be reproduced in vivo. There was no decrease in number of T. gondii positive brains by either treatment. However, the levels of infection in these brains, i. e. the number of tachyzoites, was significantly decreased upon BKI-1748 treatment alone, and the combination with artemiside did not produce any further decrease. The treatment with artemiside alone had no significant effects. A vertical transmission model could not be established since artemiside strongly interfered with pregnancy and caused abortion. These results show that is difficult to extrapolate from promising in vitro results to the situation in vivo.

Is Childhood Immune Thrombocytopenia Associated With Acquired Toxoplasmosis? An Unusual Case of Infection That Led to Acute ITP in a Greek Male Toddler and Implications for Guidelines.

INTRODUCTION: Childhood immune thrombocytopenic purpura (ITP) is a heterogeneous immune-mediated process triggered by infections, vaccines, allergies and parasites. Currently, there is little evidence in the literature beyond case reports of an association with Toxoplasma gondii (T. gondii). METHODS: The authors describe the unusual case of an earlier healthy 2.5-year-old Greek boy who developed acute ITP with a life-threatening platelet count a few days after a T. gondii infection. Evidence for the infection onset was found incidentally 3 months after the initial admission to the hospital and only after any other plausible cause of thrombocytopenia was excluded, according to diagnosis guidelines. RESULTS: The boy underwent 3 intravenous immunoglobulin treatments within a trimester, a period during which his alarming platelets count levels led to housebound activities. A quite slow recovery was only ignited after the third treatment, which was administered in conjunction with a mild antibiotic medication for the T. gondii infection. Full recovery was obtained 9 months after the initial admission, although the boy's potential scored high in clinical prediction models for developing transient ITP. CONCLUSION: There is a need for more research on ITPs with no obvious cause to investigate a causal association with toxoplasmosis. Currently, testing for diseases of greater rarity and of higher diagnostic cost than T. gondii is included in the ITP guidelines. Hence, routinely testing for toxoplasmosis when considering potential childhood ITP triggers and infection treatment complementary to treating the ITP might be the key to accelerating the healing process and improving the quality of life of otherwise confined children.

An updated review of chemical compounds with anti-Toxoplasma gondii activity.

The opportunistic apicomplexan parasite Toxoplasma gondii is the etiologic agent for toxoplasmosis, which can infect a widespread range of hosts, particularly humans and warm-blooded animals. The present chemotherapy to treat or prevent toxoplasmosis is deficient and is based on diverse drugs such as atovaquone, trimethoprim, spiramycine, which are effective in acute toxoplasmosis. Therefore, a safe chemotherapy is required for toxoplasmosis considering that its responsible agent, T. gondii, provokes severe illness and death in pregnant women and immunodeficient patients. A certain disadvantage of the available treatments is the lack of effectiveness against the tissue cyst of the parasite. A safe chemotherapy to combat toxoplasmosis should be based on the metabolic differences between the parasite and the mammalian host. This article covers different relevant molecular targets to combat this disease including the isoprenoid pathway (farnesyl diphosphate synthase, squalene synthase), dihydrofolate reductase, calcium-dependent protein kinases, histone deacetylase, mitochondrial electron transport chain, etc.

Hydroxamate-based compounds are potent inhibitors of Toxoplasma gondii HDAC biological activity.

Toxoplasmosis is a critical health issue for immune-deficient individuals and the offspring of newly infected mothers. It is caused by a unicellular intracellular parasite called Toxoplasma gondii that is found worldwide. Although efficient drugs are commonly used to treat toxoplasmosis, serious adverse events are common. Therefore, new compounds with potent anti-T. gondii activity are needed to provide better suited treatments. We have tested compounds designed to target specifically histone deacetylase enzymes. Among the 55 compounds tested, we identified three compounds showing a concentration of drug required for 50% inhibition (IC50) in the low 100 nM range with a selectivity index of more than 100. These compounds are not only active at inhibiting the growth of the parasite in vitro but also at preventing some of the consequences of the acute disease in vivo. Two of these hydroxamate based compound also induce a hyper-acetylation of the parasite histones while the parasitic acetylated tubulin level remains unchanged. These findings suggest that the enzymes regulating histone acetylation are potent therapeutic targets for the treatment of acute toxoplasmosis.

Dimedone nanoparticle as a promising approach against toxoplasmosis: In vitro and in vivo evaluation.

Toxoplasma gondii, an intracellular parasite, has shown drug resistance and therapeutic failure in recent years. Dimedone (DIM) has been introduced as a new chemical compound with anti-bacterial and anti-cancer properties. The aim of this study was to investigate the potential protective role of DIM nanoparticles in an animal model of toxoplasmosis. Cytotoxicity of DIM on Vero cell line assessed using MTT, and the effect of DIM on Toxoplasma gondii was evaluated by counting the number of parasites compared to the control group in vitro. The rate of pathogenesis and virulence of the parasite was checked on the liver cells of the animal model using hematoxylin-eosin staining. Furthermore, various parameters indicating oxidative stress were compared in mouse liver tissue in different groups. The release of the nanoparticle form was significantly longer than the free drugs. The IC50 of Nano-DIM was 60 µM and the reduction of intracellular parasite proliferation in the group Nano-DIM and Nano-PYR (Nano-primethamine) was significantly lower than the free drugs in vitro. Histopathology examination in the groups treated with dimedone nanomedicine showed that the degree of disintegration of the epithelium of the central vein of the liver and infiltration and vacuolization of liver cells were lower compared to the toxoplasmosis group. Additionally, the level of some oxidative stress indicators was observed to be lower in the nano-treated groups compared to other groups. The results of this study showed DIM can be used as a promising compound for anti-T. gondii activity and can prevent the proliferation of it in cells.

Gestational toxoplasmosis treatment changes the child's prognosis: A cohort study in southern Brazil.

BACKGROUND: We evaluate the drug treatment for pregnant women with acute toxoplasmosis to reduce the risk of congenital infection, side effects (prenatal and postnatal treatment in children) and the hazard of discontinuing the infant's medication. METHODS: We conducted a prospective cohort study to assess the risks of congenital toxoplasmosis among children born to acutely infected women with and without treatment. We examined the relationship between "exposed" and "infected children", "number of infant neutrophils", "prenatal" and "postnatal treatment". Factor analysis of mixed data (FAMD) was used to analyze the data. All children started treatment at the hospital. FINDINGS: Between 2017 and 2021, 233 pregnant women were evaluated at the University Hospital of Maringá; ninety-four met criteria for acute gestational toxoplasmosis. We followed up 61 children; eleven (18%) had the infection confirmed and 50 (82%) were free of toxoplasmosis (exposed). Children born to untreated mothers have 6.5-times higher risk of being infected; the transmission rate among untreated mothers was 50% versus 8.3% among treated ones. Three decreasing values of immunoglobulin G were a security parameter for stopping the child's medication in the exposed group (50/61). Neutropenia was the leading side effect among children and the infected had a 2.7 times higher risk. There was no correlation between maternal use of pyrimethamine and children's neutropenia. INTERPRETATION: The follow-up of women with acute T. gondii infection and their children, through a multidisciplinary team, availability of anti-T. gondii serology and pre- and post-natal treatments reduced the risk of toxoplasmosis transmission.

Zinc oxide nanoparticles produced by Zingiber officinale ameliorates acute toxoplasmosis-induced pathological and biochemical alterations and reduced parasite burden in mice model.

BACKGROUND: Although, approximately 30% of the world's population is estimated to be infected with Toxoplasma gondii (T. gondii) with serious manifestations in immunocompromised patients and pregnant females, the available treatment options for toxoplasmosis are limited with serious side effects. Therefore, it is of great importance to identify novel potent, well tolerated candidates for treatment of toxoplasmosis. The present study aimed to evaluate the effect of Zinc oxide nanoparticles (ZnO NPs) synthesized using Zingiber officinale against acute toxoplasmosis in experimentally infected mice. METHODS: The ethanolic extract of ginger was used to prepare ZnO NPs. The produced ZnO NPs were characterized in terms of structure and morphology using Fourier Transformed Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), UV- spectroscopy and scanning electron microscopy (SEM). The prepared formula was used in treatment of T. gondii RH virulent strain. Forty animals were divided into four groups, with ten mice per group. The first group was the uninfected, control group. The second group was infected but untreated. The third and the fourth groups received ZnO NPs and Spiramycin orally in a dose of 10 mg/kg and 200 mg/kg/day respectively. The effect of the used formulas on the animals survival rate, parasite burden, liver enzymes -including Alanine transaminase (ALT) and aspartate transaminase (AST)-, nitric oxide (NO) and Catalase antioxidant enzyme (CAT) activity was measured. Moreover, the effect of treatment on histopathological alterations associated with toxoplasmosis was examined. RESULTS: Mice treated with ZnO NPs showed the longest survival time with significant reduction in the parasite load in the livers and peritoneal fluids of the same group. Moreover, ZnO NPs treatment was associated with a significant reduction in the level of liver enzymes (ALT, AST) and NO and a significant increase in the antioxidant activity of CAT enzyme. SEM examination of tachyzoites from the peritoneal fluid showed marked distortion of T. gondii tachyzoites isolated from mice treated with ZnO NPs in comparison to untreated group. T. gondii induced histopathological alterations in the liver and brain were reversed by ZnO NPs treatment with restoration of normal tissue morphology. CONCLUSION: The produced formula showed a good therapeutic potential in treatment of murine toxoplasmosis as demonstrated by prolonged survival rate, reduced parasite burden, improved T. gondii associated liver injury and histopathological alterations. Thus, we assume that the protective effect observed in the current research is attributed to the antioxidant capability of NPs. Based on the results obtained from the current work, we suggest greenly produced ZnO NPs as a chemotherapeutic agent with good therapeutic potential and high levels of safety in the treatment of toxoplasmosis.

Repurposing the Medicines for Malaria Venture's COVID Box to discover potent inhibitors of Toxoplasma gondii, and in vivo efficacy evaluation of almitrine bismesylate (MMV1804175) in chronically infected mice.

Toxoplasmosis, caused by the obligate intracellular parasite Toxoplasma gondii, affects about one-third of the world's population and can cause severe congenital, neurological and ocular issues. Current treatment options are limited, and there are no human vaccines available to prevent transmission. Drug repurposing has been effective in identifying anti-T. gondii drugs. In this study, the screening of the COVID Box, a compilation of 160 compounds provided by the "Medicines for Malaria Venture" organization, was conducted to explore its potential for repurposing drugs to combat toxoplasmosis. The objective of the present work was to evaluate the compounds' ability to inhibit T. gondii tachyzoite growth, assess their cytotoxicity against human cells, examine their absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties, and investigate the potential of one candidate drug through an experimental chronic model of toxoplasmosis. Early screening identified 29 compounds that could inhibit T. gondii survival by over 80% while keeping human cell survival up to 50% at a concentration of 1 µM. The Half Effective Concentrations (EC50) of these compounds ranged from 0.04 to 0.92 µM, while the Half Cytotoxic Concentrations (CC50) ranged from 2.48 to over 50 µM. Almitrine was chosen for further evaluation due to its favorable characteristics, including anti-T. gondii activity at nanomolar concentrations, low cytotoxicity, and ADMET properties. Administering almitrine bismesylate (Vectarion®) orally at dose of 25 mg/kg/day for ten consecutive days resulted in a statistically significant (p < 0.001) reduction in parasite burden in the brains of mice chronically infected with T. gondii (ME49 strain). This was determined by quantifying the RNA of living parasites using real-time PCR. The presented results suggest that almitrine may be a promising drug candidate for additional experimental studies on toxoplasmosis and provide further evidence of the potential of the MMV collections as a valuable source of drugs to be repositioned for infectious diseases.