An in vivo appraisal of Punica granatum peel extract's ultrastructural effect on cystic echinococcosis in mice.

In the past decade, interest has significantly increased regarding the medicinal and nutritional benefits of pomegranate (Punica granatum) peel. This study examined the effects of using pomegranate peel extract (PGE) alone and in combination with albendazole (ABZ) on ultrastructural and immunological changes in cystic echinococcosis in laboratory-infected mice. Results revealed that the smallest hydatid cyst size and weight (0.48 ± 0.47mm, 0.17 ± 0.18 gm) with the highest drug efficacy (56.2%) was detected in the PGE + ABZ group, which also exhibited marked histopathological improvement. Ultrastructural changes recorded by transmission electron microscopy including fragmentation of the nucleus, glycogen depletion, and multiple lysosomes in vacuolated cytoplasm were more often observed in PGE + ABZ group. IFN-γ levels were significantly increased in the group treated with ABZ, with a notable reduction following PGE treatment, whether administered alone or in combination with ABZ. Thus, PGE enhanced the therapeutic efficiency of ABZ, with improvement in histopathological and ultrastructural changes.

Therapeutic efficacy of candidate antischistosomal drugs in a murine model of schistosomiasis mansoni.

Schistosomiasis is a neglected tropical disease associated with considerable morbidity. Praziquantel (PZQ) is effective against adult schistosomes, yet, it has little effect on juvenile stages, and PZQ resistance is emerging. Adopting the drug repurposing strategy as well as assuming enhancing the efficacy and lessening the doses and side effects, the present study aimed to investigate the in vivo therapeutic efficacy of the widely used antiarrhythmic, amiodarone, and diuretic, spironolactone, and combinations of them compared to PZQ. Mice were infected by Schistosoma mansoni "S. mansoni" cercariae (Egyptian strain), then they were divided into two major groups: Early- [3 weeks post-infection (wpi)] and late- [6 wpi] treated. Each group was subdivided into seven subgroups: positive control, PZQ, amiodarone, spironolactone, PZQ combined with amiodarone, PZQ combined with spironolactone, and amiodarone combined with spironolactone-treated groups. Among the early-treated groups, spironolactone had the best therapeutic impact indicated by a 69.4% reduction of total worm burden (TWB), 38.6% and 48.4% reduction of liver and intestine egg load, and a significant reduction of liver granuloma number by 49%. Whereas, among the late-treated groups, amiodarone combined with PZQ was superior to PZQ alone evidenced by 96.1% reduction of TWB with the total disappearance of female and copula in the liver and intestine, 53.1% and 84.9% reduction of liver and intestine egg load, and a significant reduction of liver granuloma number by 67.6%. Comparatively, spironolactone was superior to PZQ and amiodarone in the early treatment phase targeting immature stages, while amiodarone had a more potent effect when combined with PZQ in the late treatment phase targeting mature schistosomes.

First report of apparent praziquantel resistance in Dipylidium caninum in Europe.

Dipylidium caninum is a common tapeworm of dogs. Two cases of praziquantel resistance have been described in D. caninum in the United States. No further reports have been published to the authors' knowledge. Here, the case of a dog imported to Switzerland from Spain with a history of chronic excretion of tapeworm proglottids and unresponsiveness to praziquantel treatments is reported. Clinical signs were mild (restlessness, tenesmus, anal pruritus, squashy feces) and flea infestation could be ruled out. Infection with D. caninum was confirmed through morphological and genetic parasite identification. Different subsequently applied anthelmintic compounds and protocols, including epsiprantel, did not confer the desired effects. Proglottid shedding only stopped after oral mebendazole administration of 86.2 mg kg−1 body weight for 5 consecutive days. Clinical signs resolved and the dog remained coproscopically negative during a follow-up period of 10 months after the last treatment. This case represents the first reported apparent praziquantel and epsiprantel resistance in D. caninum in Europe. Treatment was extremely challenging especially due to the limited availability of efficacious alternative compounds.

The in vitro rumen exsheathment test for studying the effect of plant extracts on the exsheathment of Haemonchus contortus infective larvae.

This study applied the in vitro rumen exsheathment test (IVRET) to evaluate the exsheathment kinetics of Haemonchus contortus infective larvae (L3) incubated in ruminal liquor (RL) containing acetone:water extracts of Acacia pennatula (AP), Gymnopodium floribundum (GF), Havardia albicans (HA) or Lysiloma latisiliquum (LL). The role of polyphenols in the biological activity of the evaluated extracts was also determined. Larvae were incubated in RL either alone or added with a different plant extract (AP, GF, HA, or LL) at 1200 µg/mL. Polyethylene glycol (PEG) was added to block polyphenols in each treatment (RL+PEG, AP+PEG, GF+PEG, HA+PEG, and LL+PEG). After incubation times of 0, 1, 3, 6, 9, and 24 h, the exsheathment process was stopped to count the number of ensheathed and exsheathed L3. A Log-Logistic model was used to determine the L3 exsheathment kinetics in the different RL treatments. The inflection point of the respective kinetic curves, which indicates the time to reach 50 % exsheathed L3 (T50), was the only parameter that differed when comparing the exsheathment models (99 % probability of difference). The T50 values obtained for GF, HA, and LL treatments (T50 = 7.11 - 7.58 h) were higher in comparison to the T50 of RL (5.72 h) (≥ 70 % probability of difference). The L3 incubated in RL added with GF, HA, and LL extracts delayed their exsheathment at 3 and 6 h of incubation (28.71 - 48.06 % exsheathment reduction) compared to the RL treatment. The T50 value for AP, AP+PEG, GF+PEG, HA+PEG, and LL+PEG were similar to RL and RL+PEG (T50 = 5.34 - 6.97 h). In conclusion, the IVRET can be used to identify plants with the potential to delay the exsheathment of H. contortus L3 in the ruminal liquor. The acetone:water extracts of G. floribundum, H. albicans, and L. latisiliquum delayed the T50 of H. contortus exsheathment, which was evident at 3 and 6 h of incubation in ruminal liquor. The observed exsheathment delay was attributed to the polyphenol content of the extracts.

Baiting not-owned dogs against Echinococcus granulosus: innovative tools for integrated control.

Cystic echinococcosis (CE), caused by the larval stage of the cestode Echinococcus granulosus, is one of the most widespread zoonoses in Mediterranean countries. Baiting not-owned dogs with praziquantel (PZQ), due to their key role in the maintaining the transmission of CE, currently appears to be the most effective way to limit the transmission of CE, as well as an important aspect to introduce for the control of this parasitic disease. Therefore, this study aims to test 3 types of PZQ-based baits by evaluating different parameters (integrity over time, attractiveness and palatability for dogs, and mechanical resistance after release to different altitudes) and the bait acceptance in field by target animals, i.e. not-owned dogs, by using camera traps. The double PZQ-laced baits (with a double layer of highly palatable chews) showed the greatest resistance in the environment while also preserving the attractiveness and palatability up to 10 days, also withstood heights of 25 m, thus resulting as the most suitable also for drone delivery. The results on the field showed that most of the baits were consumed by not-owned dogs (82.2%), while the remaining were consumed by wild boars (8.9%), foxes (6.7%), badgers (1.1%) and hedgehogs (1.1%), confirming the specific and high attractiveness of the double PZQ-laced baits for the target population and highlights how an anthelmintic baiting programme may be a viable tool for the management of E. granulosus among free-ranging dog populations in endemic rural areas.

Diet modulates strongyle infection and microbiota in the large intestine of horses.

The use of anthelminthic drugs has several drawbacks, including the selection of resistant parasite strains. Alternative avenues to mitigate the negative effects of helminth infection involve dietary interventions that might affect resistance and/or tolerance by improving host immunity, modulating the microbiota, or exerting direct anthelmintic effects. The aim of this study was to assess the impact of diet on strongyle infection in horses, specifically through immune-mediated, microbiota-mediated, or direct anthelmintic effects. Horses that were naturally infected with strongyles were fed either a high-fiber or high-starch diet, supplemented with either polyphenol-rich pellets (dehydrated sainfoin) or control pellets (sunflower and hay). When horses were fed a high-starch diet, they excreted more strongyle eggs. Adding sainfoin in the high-starch diet reduced egg excretion. Additionally, sainfoin decreased larval motility whatever the diet. Moreover, the high-starch diet led to a lower fecal bacterial diversity, structural differences in fecal microbiota, lower fecal pH, lower blood acetate, and lower hematocrit compared to the high-fiber diet. Circulating levels of Th1 and Th2 cytokines, lipopolysaccharides, procalcitonin, and white blood cells proportions did not differ between diets. Overall, this study highlights the role of dietary manipulations as an alternative strategy to mitigate the effect of helminth infection and suggests that, in addition to the direct effects, changes in the intestinal ecosystem are the possible underlying mechanism.

Anthelmintic efficacy of an organic fraction from Guazuma ulmifolia leaves and evaluation of reactive oxidative stress on Haemonchus contortus.

This study describes the anthelmintic efficacy of an organic fraction (EtOAc-F) from Guazuma ulmifolia leaves and the evaluation of its reactive oxidative stress on Haemonchus contortus. The first step was to assess the anthelmintic effect of EtOAc-F at 0.0, 3.5, 7.0 and 14 mg kg of body weight (BW) in gerbil's (Meriones unguiculatus) artificially infected with H. contortus infective larvae (L3). The second step was to evaluate the preliminary toxicity after oral administration of the EtOAc-F in gerbils. Finally, the third step was to determine the relative expression of biomarkers such as glutathione (GPx), catalase (CAT), and superoxide dismutase (SOD) against H. contortus L3 post-exposition to EtOAc-F. Additionally, the less-polar compounds of EtOAc-F were identified by gas mass spectrophotometry (GC-MS). The highest anthelmintic efficacy (97.34%) of the organic fraction was found in the gerbils treated with the 14 mg/kg of BW. Histopathological analysis did not reveal changes in tissues. The relative expression reflects overexpression of GPx (p<0.05, fold change: 14.35) and over expression of SOD (p≤0.05, fold change: 0.18) in H. contortus L3 exposed to 97.44 mg/mL of EtOAc-F compared with negative control. The GC-MS analysis revealed the presence of 4-hydroxybenzaldehyde (1), leucoanthocyanidin derivative (2), coniferyl alcohol (3), ferulic acid methyl ester acetate (4), 2,3,4-trimethoxycinnamic acid (5) and epiyangambin (6) as major compounds. According to these results, the EtOAc-F from G. ulmifolia leaves exhibit anthelmintic effect and increased the stress biomarkers on H. contortus.

Anti-Opisthorchis felineus effects of artemisinin derivatives: An in vitro study.

BACKGROUND: The drug of choice for the treatment of opisthorchiasis caused by trematodes Opisthorchis viverrini and O. felineus is praziquantel (PZQ), but there is a constant search for new anthelmintics, including those of plant origin. Positive results on the use of artemisinin derivatives against O. viverrini opisthorchiasis have been shown previously, but the effect of these compounds on O. felineus has not been studied. Therefore, here, a comparative analysis of anthelmintic properties of artemisinin derivatives (artesunate [AS], artemether [AM], and dihydroartemisinin [DHA]) was carried out in vitro in relation to PZQ. Experiments were performed on newly excysted metacercariae (NEMs) and adult flukes of O. felineus. RESULTS: Dose- and time-dependent effects of artemisinin derivatives and of PZQ were assessed in terms of motility and mortality of both NEMs and adult flukes. The most pronounced anthelmintic action was exerted by DHA, whose half-maximal inhibitory concentrations (IC50) of 1.9 (NEMs) and 2.02 µg/mL (adult flukes) were lower than those of PZQ (0.56 and 0.25 µg/mL, respectively). In contrast to PZQ, the effects of DHA and AS were similar when we compared the two developmental stages of O. felineus (NEMs and adult flukes). In addition, AM, AS, and especially DHA at doses of 100 µg/mL disrupted tegument integrity in adult flukes, which was not observed with PZQ. CONCLUSIONS: Artemisinin derivatives (AS, AM, and DHA) have good anthelmintic efficacy against the trematode O. felineus, and the action of these substances is comparable to (and sometimes better than) the effects of PZQ.

A phenotypic screen of the Global Health Priority Box identifies an insecticide with anthelmintic activity.

BACKGROUND: Infection with parasitic nematodes (helminths), particularly those of the order Strongylida (such as Haemonchus contortus), can cause significant and burdensome diseases in humans and animals. Widespread drug (anthelmintic) resistance in livestock parasites, the absence of vaccines against most of these nematodes, and a lack of new and effective chemical entities on the commercial market demands the discovery of new anthelmintics. In the present study, we searched the Global Health Priority Box (Medicines for Malaria Venture) for new candidates for anthelmintic development. METHODS: We employed a whole-organism, motility-based phenotypic screening assay to identify compounds from the Global Health Priority Box with activity against larvae of the model parasite H. contortus, and the free-living comparator nematode Caenorhabditis elegans. Hit compounds were further validated via dose-response assays, with lead candidates then assessed for nematocidal activity against H. contortus adult worms, and additionally, for cytotoxic and mitotoxic effects on human hepatoma (HepG2) cells. RESULTS: The primary screen against H. contortus and C. elegans revealed or reidentified 16 hit compounds; further validation established MMV1794206, otherwise known as 'flufenerim', as a significant inhibitor of H. contortus larval motility (half-maximal inhibitory concentration [IC50] = 18 µM) and development (IC50 = 1.2 µM), H. contortus adult female motility (100% after 12 h of incubation) and C. elegans larval motility (IC50 = 0.22 µM). Further testing on a mammalian cell line (human hepatoma HepG2 cells), however, identified flufenerim to be both cytotoxic (half-maximal cytotoxic concentration [CC50] < 0.7 µM) and mitotoxic (half-maximal mitotoxic concentration [MC50] < 0.7 µM). CONCLUSIONS: The in vitro efficacy of MMV1794206 against the most pathogenic stages of H. contortus, as well as the free-living C. elegans, suggests the potential for development as a broad-spectrum anthelmintic compound; however, the high toxicity towards mammalian cells presents a significant hindrance. Further work should seek to establish the protein-drug interactions of MMV1794206 in a nematode model, to unravel the mechanism of action, in addition to an advanced structure-activity relationship investigation to optimise anthelmintic activity and eliminate mammalian cell toxicity.

Effects of structurally distinct human HDAC6 and HDAC6/HDAC8 inhibitors against S. mansoni larval and adult worm stages.

Schistosomiasis is a major neglected parasitic disease that affects more than 240 million people worldwide caused by Platyhelminthes of the genus Schistosoma. The treatment of schistosomiasis relies on the long-term application of a single safe drug, praziquantel (PZQ). Unfortunately, PZQ is very effective on adult parasites and poorly on larval stage and immature juvenile worms; this can partially explain the re-infection in endemic areas where patients are likely to host parasites at different developmental stages concurrently. Moreover, the risk of development of drug resistance because of the widespread use of a single drug in a large population is nowadays a serious threat. Hence, research aimed at identifying novel drugs to be used alone or in combination with PZQ is needed. Schistosomes display morphologically distinct stages during their life cycle and epigenetic mechanisms are known to play important roles in parasite growth, survival, and development. Histone deacetylase (HDAC) enzymes, particularly HDAC8, are considered valuable for therapeutic intervention for the treatment of schistosomiasis. Herein, we report the phenotypic screening on both larvae and adult Schistosoma mansoni stages of structurally different HDAC inhibitors selected from the in-house Siena library. All molecules have previously shown inhibition profiles on human HDAC6 and/or HDAC8 enzymes. Among them we identified a quinolone-based HDAC inhibitor, NF2839, that impacts larval and adult parasites as well as egg viability and maturation in vitro. Importantly, this quinolone-based compound also increases histone and tubulin acetylation in S. mansoni parasites, thus representing a leading candidate for the development of new generation anti-Schistosoma chemotherapeutics.

Assessing the effectiveness of fenbendazole supramolecular complexes against schistosomiasis, monieziosis and parabronemosis in sheep.

Helminth infections pose a significant economic threat to livestock production, causing productivity declines and, in severe cases, mortality. Conventional anthelmintics, exemplified by fenbendazole, face challenges related to low solubility and the necessity for high doses. This study explores the potential of supramolecular complexes, created through mechanochemical modifications, to address these limitations. The study focuses on two key anthelmintics, praziquantel (PZQ) and fenbendazole (FBZ), employing mechanochemical techniques to enhance their solubility and efficacy. Solid dispersions (SD) of PZQ with polymers and dioctyl sulfosuccine sodium (DSS) and fenbendazole with licorice extract (ES) and DSS were prepared. The helminthicidal activity of these complexes was assessed through helminthological dissections of sheep infected with Schistosoma turkestanicum, moniesiasis, and parabronemosis. In the assessment of supramolecular complex of FBZ (SMCF) at doses ranging from 1.0 to 3.0 mg/kg for the active substance (AS), optimal efficacy was observed with the fenbendazole formulation containing arabinogalactan and polyvinylpyrrolidone at a 3.0 mg/kg dosage. At this concentration, the formulation demonstrated a remarkable 100% efficacy in treating spontaneous monieziosis in sheep, caused by Moniezia expansa (Rudolphi, 1810) and M. benedenii (Moniez, 1879). Furthermore, the SMCF, administered at doses of 1.0, 2.0, and 3.0 mg/kg, exhibited efficacy rates of 42.8%, 85.7%, and 100%, respectively, against the causative agent of parabronemosis (Parabronema skrjabini Rassowska, 1924). Mechanochemical modifications, yielding supramolecular complexes of PZQ and FBZ, present a breakthrough in anthelmintic development. These complexes address solubility issues and significantly reduce required doses, offering a practical solution for combating helminth infections in livestock. The study underscores the potential of supramolecular formulations for revolutionizing helminthiasis management, thereby enhancing the overall health and productivity of livestock.

Progress interrogating TRPMPZQ as the target of praziquantel.

The drug praziquantel (PZQ) has served as the long-standing drug therapy for treatment of infections caused by parasitic flatworms. These encompass diseases caused by parasitic blood, lung, and liver flukes, as well as various tapeworm infections. Despite a history of clinical usage spanning over 4 decades, the parasite target of PZQ has long resisted identification. However, a flatworm transient receptor potential ion channel from the melastatin subfamily (TRPMPZQ) was recently identified as a target for PZQ action. Here, recent experimental progress interrogating TRPMPZQ is evaluated, encompassing biochemical, pharmacological, genetic, and comparative phylogenetic data that highlight the properties of this ion channel. Various lines of evidence that support TRPMPZQ being the therapeutic target of PZQ are presented, together with additional priorities for further research into the mechanism of action of this important clinical drug.

Unlocking the Pharmacological Potential of Benzimidazole Derivatives: A Pathway to Drug Development.

Heterocyclic molecules have fascinated a massive interest in medicinal chemistry. They are heterocyclic compounds that have gained significance due to their diverse variety of pharmacological activities. Benzimidazole is a heterocyclic compound consisting of benzene and imidazole rings. The ease of synthesis and the structural versatility of benzimidazole make it a promising scaffold for drug development. Many biological actions of benzimidazole derivatives have been well documented, including antibacterial, antiviral, anticancer, anti-inflammatory, antitubercular, and anthelmintic properties. The mechanism of action of benzimidazole derivatives varies with their chemical structure and target enzyme. This review has explored numerous methods for producing benzimidazole derivatives as well as a broad range of pharmacological activities. SAR investigations are also discussed in this review as they provide crucial details regarding the essential structural qualities that benzimidazole derivatives must have in order to be biologically active, which could aid in the rational design of new drug candidates. Benzimidazole scaffold is an exclusive structure in drug design and discovery. Many new pharmaceutical drugs containing benzimidazole are anticipated to be available within the next ten years as a result of the extensive therapeutic applications of benzimidazole and its derivatives. This review inspired many researchers to develop more biologically active compounds bearing benzimidazole, expanding the scope of finding a remedy for other diseases. From this study, we concluded that 2-substituted benzimidazole was considered more extensively by researchers.

A single locus determines praziquantel response in Schistosoma mansoni.

We previously performed a genome-wide association study (GWAS) to identify the genetic basis of praziquantel (PZQ) response in schistosomes, identifying two quantitative trait loci situated on chromosomes 2 and 3. We reanalyzed this GWAS using the latest (version 10) genome assembly showing that a single locus on chromosome 3, rather than two independent loci, determines drug response. These results reveal that PZQ response is monogenic and demonstrates the importance of high-quality genomic information.

The feeding of heather (Calluna vulgaris) to Teladorsagia circumcincta infected lambs reduces parasitism but can detrimentally impact performance.

Gastrointestinal nematode (GIN) infections impact small ruminant health, welfare, and production across farming systems. Rising anthelmintic resistance and regulation of synthetic drug use in organic farming is driving research and development of sustainable alternatives for GIN control. One alternative is the feeding of plants that contain secondary metabolites (PSMs) e.g., proanthocyanidins (PA, syn. condensed tannins) that have shown anthelmintic potential. However, PSMs can potentially impair performance, arising from reduced palatability and thus intake, digestibility or even toxicity effects. In this study, we tested the trade-off between the antiparasitic and anti-nutritional effects of heather consumption by lambs. The impact of additional feeding of a nematophagous fungus (Duddingtonia flagrans) on larval development was also explored. Lambs infected with Teladorsagia circumcincta or uninfected controls, were offered ad libitum heather, or a control chopped hay for 22 days during the infection patent period. Eight days into the patent period, parasitised lambs were supplemented (or remained unsupplemented) with D. flagrans for a 5-day period. Performance and infection metrics were recorded, and polyphenol levels in the heather and control hay were measured to investigate their association with activity. The lambs consumed heather at approximately 20% of their dry matter intake, which was sufficient to exhibit significant anthelmintic effects via a reduction in total egg output (P = 0.007), compared to hay-fed lambs; the magnitude of the reduction over time in heather fed lambs was almost 10-fold compared to control lambs. Negative effects on production were shown, as heather-fed lambs weighed 6% less than hay-fed lambs (P < 0.001), even though dry matter intake (DMI) of heather increased over time. D. flagrans supplementation lowered larval recovery in the faeces of infected lambs by 31.8% (P = 0.003), although no interactions between feeding heather and D. flagrans were observed (P = 0.337). There was no significant correlation between PA, or other polyphenol subgroups in the diet and egg output, which suggests that any association between heather feeding and anthelmintic effect is not simply and directly attributable to the measured polyphenols. The level of heather intake in this study showed no antagonistic effects on D. flagrans, demonstrating the methods can be used in combination, but provide no additive effect on overall anthelmintic efficacies. In conclusion, heather feeding can assist to reduce egg outputs in infected sheep, but at 20% of DMI negative effects on lamb performance can be expected which may outweigh any antiparasitic benefits.

Pumpkin seeds (Cucurbita pepo subsp. ovifera) decoction promotes Trichinella spiralis expulsion during intestinal phase via "Weep and Sweep" mechanism.

Trichinosis is a zoonotic disease of communal health concern as it instigated human outbreaks in several countries. Besides, the development of resistance, traditional therapy has numerous antagonistic effects. Thereby, finding efficient natural alternatives is required. In comparison to albendazole, this study evaluated the impact of pumpkin decoction on Trichinella spiralis in experimentally infected mice. The anthelmintic action of pumpkin decoction (500 mg/kg) was determined using T. spiralis infected mice in enteric phase for 5 days. Pumpkin decoction anthelmintic activity fortified by mixing with honey (1:1). Pumpkin decoction and Pumpkin decoction-honey mixture were evaluated by comprising with reference drug, albendazole (50 mg/kg). The T. spiralis adult count was significantly lower in all treated groups, with the pumpkin decoction-honey mixture showing the largest reduction (83.2%) when compared to the infected group (P ≤ 0.001). The intestinal histological changes and the level of COX-2 expression in the intestinal tissue were both significantly reduced in the same group. The pumpkin decoction improved the immune response, as evidenced by a significant decrease in nitric oxide (NO) and tumor necrosis factor (TNF-α) and a significant increase in the expression of the transforming growth factor (TGF-1ß) and interleukin-17 (IL-17). The pumpkin decoction's anthelmintic action was facilitated by the TGF-1ß and IL-17-driven Weep and Sweep mechanism. Both administration of pumpkin decoction beside honey showed the best treatment group that resulted in high infection reduction besides amelioration of biochemical markers and restoration of histological to normal state. In conclusion, pumpkin decoction is highly effective against T. spiralis which could be a promising alternative herbal drug and the pumpkin decoction effect was higher in the case of combination with honey.

Expression profile analysis of the transient receptor potential (TRPM) channel, a possible target of praziquantel in Schistosoma japonicum.

The WHO considers schistosomiasis, which is controlled by the mass administration of the drug praziquantel (PZQ), to be a neglected tropical disease. Despite its clinical use for over four decades, PZQ remains the only choice of chemotherapy against this disease. Regarding the previous studies that demonstrated that PZQ activates the transient receptor potential (TRP) channel in Schistosoma mansoni (Sm.TRPMPZQ), the expression profile of the ortholog of this channel gene (Smp_246790.5) in S. japonicum (EWB00_008853) (Sj.TRPMPZQ) was analyzed. The relative expression of this gene in various stages of the parasite lifecycle was analyzed by quantitative real-time reverse transcription-PCR (qRT-PCR), and the expression of Sj.TRPMPZQ was observed by immunohistochemical staining using anti-serum against the recombinant Sj.TRPMPZQ protein. qRT-PCR revealed the significantly lower mRNA expression in the snail stage in comparison to other stages (p < 0.01). The relative quantity of the Sj.TRPMPZQ expression for paired females, unpaired males, and eggs was 60%, 56%, and 68%, respectively, in comparison to paired males that showed the highest expression (p < 0.05). Interestingly, immunostaining demonstrated that Sj.TRPMPZQ is expressed in the parenchyma which contains muscle cells, neuronal cells and tegument cells in adult worms. This may support the two major effects of PZQ-worm paralysis and tegument disruption-induced by channel activation. Moreover, the channel was expressed in both the eggshell and the miracidia inside, but could not be observed in sporocyst. These results suggest that the expression of Sj.TRPMPQZ corresponds to the known sensitivity of S. japonicum to PZQ.

Curcumin-PVP improves the in vitro efficacy of ivermectin against resistant and susceptible Haemonchus contortus.

Ivermectin (IVM) resistance in parasitic nematodes such as Haemonchus contortus has spurred a search for substances that help to recover its efficacy. One potential agent is the natural product curcumin (CUR). In this study, CUR was combined with polyvinylpyrrolidone (PVP) (CUR/PVP) to improve its solubility and biological applicability. This study determined the effect of CUR preincubation on the effective concentration 50% (EC50) of IVM in three H. contortus isolates with different susceptibilities to IVM. The IVM EC50 was determined for three H. contortus isolates with different IVM susceptibilities using the larval migration inhibition (LMI) test. The three isolates were (i) PARAISO (IVM resistant), (ii) FMVZ-UADY (IVM susceptible), and (iii) CENID-SAI INIFAP (reference IVM susceptible). The L3 of each isolate were preincubated for 3 h with one of three concentrations of CUR (µg curcumin/mL): CONC-1 (3.67), CONC-2 (5.67), or CONC-3 (8.48). Corresponding controls were performed without CUR. The EC50 of IVM was determined for each isolate after they were exposed to the different CUR concentrations. The EC50 of IVM differed between the isolates PARAISO > FMVZ-UADY > CENID-SAI INIFAP (P < 0.05). The CUR preincubation at CONC-1 did not decrease the EC50 of IVM for any of the three isolates, suggesting a hormetic effect. By contrast, CUR preincubation at CONC-2 or CONC-3 decreased the IVM EC50 for the PARAISO isolate (P < 0.05) compared with the reference isolate and reduced the EC50 of IVM for the FMVZ-UADY and CENID-SAI INIFAP isolates below the EC50 for the CENID-SAI INIFAP isolate without CUR preincubation. In conclusion, preincubation of H. contortus L3 with CUR reduced the EC50 of IVM for field isolates classified as resistant and susceptible to IVM. The CUR preincubation reduced the IVM resistance factor in the different isolates tested.

Assessing the Effects of One-Time Praziquantel Treatment on Urogenital Lesions Detected by Ultrasound in Schistosoma haematobium-Infected Individuals in Chad.

The objective was to determine the impact of a single dose of praziquantel on urogenital lesions caused by Schistosoma haematobium. Ultrasound (US) was performed on three age groups of subjects with a positive test for hematuria, with the first examination performed in November 2017 and a follow-up visit 7 months later. None of the subjects had previously received treatment. The participants were categorized into three distinct age groups: group 1 = 1-15 years, group 2 = 15-30 years, and group 3 = ≥ 30 years. A total of 250 people from these three groups underwent screening: 99 in group 1, 90 in group 2, and 61 in group 3, among whom 131 (52.4%) had at least one detectable lesion of the urogenital tract on US. Follow-up US after 7 months was possible in 60%, 67%, and 77% of the respective groups (with lesions). The anomalies disappeared in 80% of individuals in group 1, 76% of those in group 2, and 65% in group 3. With the exception of calcifications, most visible anomalies had been resolved. The total number of anomalies is low. Severe obstructive uropathy was not detected. We can conclude that single treatment with praziquantel is able to cure visible anomalies, with the exception of calcifications. The low rate of anomalies, compared with levels in the literature, is speculated to be due to undetected death by obstructive uropathy caused by S. haematobium. This requires further investigation.

The anthelmintic meclonazepam activates a schistosome transient receptor potential channel.

Parasitic flatworms cause various clinical and veterinary infections that impart a huge burden worldwide. The most clinically impactful infection is schistosomiasis, a neglected tropical disease caused by parasitic blood flukes. Schistosomiasis is treated with praziquantel (PZQ), an old drug introduced over 40 years ago. New drugs are urgently needed, as while PZQ is broadly effective it suffers from several limitations including poor efficacy against juvenile worms, which may prevent it from being completely curative. An old compound that retains efficacy against juvenile worms is the benzodiazepine meclonazepam (MCLZ). However, host side effects caused by benzodiazepines preclude development of MCLZ as a drug and MCLZ lacks an identified parasite target to catalyze rational drug design for engineering out human host activity. Here, we identify a transient receptor potential ion channel of the melastatin subfamily, named TRPMMCLZ, as a parasite target of MCLZ. MCLZ potently activates Schistosoma mansoni TRPMMCLZ through engagement of a binding pocket within the voltage-sensor-like domain of the ion channel to cause worm paralysis, tissue depolarization, and surface damage. TRPMMCLZ reproduces all known features of MCLZ action on schistosomes, including a lower activity versus Schistosoma japonicum, which is explained by a polymorphism within this voltage-sensor-like domain-binding pocket. TRPMMCLZ is distinct from the TRP channel targeted by PZQ (TRPMPZQ), with both anthelmintic chemotypes targeting unique parasite TRPM paralogs. This advances TRPMMCLZ as a novel druggable target that could circumvent any target-based resistance emerging in response to current mass drug administration campaigns centered on PZQ.