Late-Stage Diversification of Pyrazoles as Antileishmanial Agents

N-Pyrazolylcarboxamides and N-pyrazolylureas represent promising lead compounds for the development of novel antileishmanial drugs. Herein, we report the late-stage diversification of 3-bromopyrazoles 10 A/B and 14 A by Pd-catalyzed Sonogashira and Suzuki-Miyaura cross coupling reactions. The electron-withdrawing properties of the cyano moiety in 4-position of the pyrazole ring limited the acylation of the primary amino moiety in 5-position. A large set of pyrazoles bearing diverse aryl and alkynyl substituents in 3-position was prepared and the antileishmanial and antitrypanosomal activity was recorded. The urea 38 lacking the electron withdrawing cyano moiety in 4-position and containing the large 4-benzylpiperidinoo moiety exhibited a modest antileishmanial (IC50=19 μM) and antitrypanosomal activity (IC50=7.9 μM)). However, its considerable toxicity against the PMM and MRC-5 cells indicates low selectivity, i. e. a small gap between the desired antiparasitic activity and undesired cytotoxicity of <2- to 4-fold.

Recombinant CD5 and CD6 Ectodomains Induce Antiparasitic and Immunomodulatory Effects in Secondary Cystic Echinococcosis

Scavenger receptors participate in a wide range of biological functions after binding to multiple non-self or altered self-ligands. Among them, CD5 and CD6 are lymphocyte scavenger receptors known to interact with different microbial-associated molecular patterns, and the administration of the recombinant soluble ectodomains of human CD5 (rshCD5) and/or CD6 (rshCD6) has shown therapeutic/prophylactic potential in experimental models of fungal, bacterial and echinococcal infections. The latter is a zoonosis caused by the larval stage of the cestode parasite Echinococcus granulosus sensu lato, which in humans can induce secondary cystic echinococcosis (CE) after the spillage of protoscoleces contained within fertile cysts, either spontaneously or during surgical removal of primary hydatid cysts. Herein, we have analysed the mechanisms behind the significant protection observed in the mouse model of secondary CE following prophylactic administration of rshCD5 or rshCD6. Our results show that both molecules exhibit intrinsic antiparasitic activities in vitro, as well as immunomodulatory functions during early secondary CE, mainly through Th1/Th17 cytokine bias and promotion of peritoneal polyreactive antibodies. These data support the relevance of the parasite components bound by rshCD5 and rshCD6, as well as the potential of their prophylactic administration as a useful strategy to reduce secondary CE in patients.

Insights into the Mechanism of Action of the Degraded Limonoid Prieurianin

Limonoids are extremely diversified in plants, with many categories of products bearing an intact, rearranged or fragmented oxygenated scaffold. A specific subgroup of fragmented or degraded limonoids derives from the tetranortriterpenoid prieurianin, initially isolated from the tree Trichilia prieuriana but also found in other plants of the Meliaceae family, including the more abundant species Aphanamixis polystachya. Prieurianin-type limonoids include about seventy compounds, among which are dregeanin and rohitukin. Prieurianin and analogs exhibit insecticidal, antimicrobial, antiadipogenic and/or antiparasitic properties but their mechanism of action remains ill-defined at present. Previous studies have shown that prieurianin, initially known as endosidin 1, stabilizes the actin cytoskeleton in plant and mammalian cells via the modulation of the architecture and dynamic of the actin network, most likely via interference with actin-binding proteins. A new mechanistic hypothesis is advanced here based on the recent discovery of the targeting of the chaperone protein Hsp47 by the fragmented limonoid fraxinellone. Molecular modeling suggested that prieurianin and, to a lesser extent dregeanin, can form very stable complexes with Hsp47 at the protein-collagen interface. Hsp-binding may account for the insecticidal action of the product. The present review draws up a new mechanistic portrait of prieurianin and provides an overview of the pharmacological properties of this atypical limonoid and its chemical family.

Anti-Trichomonas vaginalis Activity of Marine Ascidians (Tunicates; Ascidiacea) from the Bushehr Province, Iran

Objective

The aim of the current research is to evaluate the antiparasite effects of compounds isolated from marine ascidian tunicates on Trichomonas vaginalis.

Methods

Ascidian tunicates after collection were cut into small pieces, freeze-dried, and powdered. The resulting material was subjected to extraction in double-distilled water, ethanol, n-hexane, and dichloromethane. To fractionate the extracts and identify the most bioactive compound, silica gel column chromatography and GC-M/S analysis were used.

Results

Fraction 18 of silica gel column chromatography of ethanol extract was the most effective against T. vaginalis. The respective IC50, CC50, and SI values for fraction 18 were 28.62 μg/mL, ˃800 μg/mL, and ˃27.95. GC-M/S analysis of this fraction identified a major phenolic compound (2, 4-bis (1, 1-dimethyl ethyl), whose toxicity against vero cells was only 10.15%.

Conclusion

The ethanolic fraction containing phenol-2,4-bis (1,1-dimethylethyl), which has a potent lethality effect on T. vaginalis, may be considered as an antiparasite drug candidate.

Amoebic colitis and liver abscess: A rare case of autochthonous invasive infection due to Entamoeba histolytica

We report an unusual and confirmed case of invasive amebiasis in a non-endemic area where the source of infection remains unknown. During her admission, the patient developed amebic colitis and extraintestinal liver abscess with a favorable outcome following the antiparasitic therapy.

Verminous pneumonia in European hedgehogs (Erinaceus europaeus)

The European hedgehog (Erinaceus europaeus) is a common wildlife species in European countries. Populations are declining due to anthropogenic factors and natural diseases. Verminous pneumonia has been observed as a frequent infectious disease in hedgehogs submitted for diagnostic postmortem examination. This prompted the present in-depth investigation on the lungs of 27 necropsied hedgehogs with confirmed lungworm infections, with or without antiparasitic treatment prior to death. The histological and/or parasitic (fecal samples) examination identified Capillaria aerophila infection in most animals (82%). The parasites were found free in the airway lumen and/or within the airway epithelium, from the larynx to bronchioles. Embedded worms and eggs were associated with epithelial hyperplasia or metaplasia, and long-term inflammation. More than half of the animals (59%) carried Crenosoma striatum, and 41% had a coinfection. C striatum adults were predominantly found free in the lumen of bronchi and bronchioles, and larvae were occasionally seen in granulomas in the pulmonary interstitium, the liver, and the intestine. Independent of the parasite species, a lymphoplasmacytic peribronchitis and, less frequently, interstitial infiltration of eosinophils, neutrophils, and macrophages as well as pneumocyte type II hyperplasia was seen. Interestingly, the extent of pneumonia was not correlated with age, respiratory clinical signs, antiparasitic treatment, or single or coinfection. Verminous pneumonia appeared to be the cause of death in over 25% of the animals, indicating that these parasites not only coexist with hedgehogs but can also be a primary pathogen in this species.

Sanguinarine: an alkaloid with promising in vitro and in vivo antiparasitic activity against different developmental stages of Schistosoma mansoni and in silico pharmacokinetic properties (ADMET)

The objective of the study was to evaluate the in vitro and in vivo schistosomicidal activity of sanguinarine (SA) on Schistosoma mansoni and its in silico pharmacokinetic parameters. ADMET parameters and oral bioavailability were evaluated using the PkCSM and SwissADME platforms, respectively. The activity of SA in vitro, at the concentrations of 1.0-25 µM, was analyzed through the parameters of motility, mortality, and cell viability of the worms at intervals of 3-24 h. Mice were infected with cercariae and treated by gavage with SA (5 mg/kg/day, in a single dose or two doses of 2.5 mg/kg every 12 h for 5 consecutive days) on the 1st (skin schistosomula), 14th (pulmonary schistosomula), 28th (young worms), and 45th (adult worms) days after infection. In vitro and in vivo praziquantel was the control. In vitro, SA showed schistosomicidal activity against schistosomula, young worms, and couples; with total mortality and reduced cell viability at low concentrations and incubation time. In a single dose of 5 mg/kg/day, SA reduces the total worm load by 47.6%, 54%, 55.2%, and 27.1%, and female worms at 52.0%, 39.1%, 52.7%, and 20.2%, respectively, results which are similar to the 2.5 mg/kg/day dose. SA reduced the load of eggs in the liver, and in histopathological and histomorphometric analyses, there was a reduction in the number and volume of hepatic granulomas, which exhibited less inflammatory infiltrate. SA has promising in vitro and in vivo schistosomicidal activity against different developmental stages of S. mansoni, in addition to reducing granulomatous liver lesions. Furthermore, in silico, SA showed good predictive pharmacokinetic ADMET profiles.

Application of the SeDeM system for the preparation of antiparasitic tablets from mesquite flour for use in sheep

The use of herbal medicine to treat various diseases is becoming increasingly important as an alternative therapy. Numerous plants have been traditionally used for different purposes, including antiparasitic in humans and animals. Diseases caused by gastrointestinal parasites in ruminants, especially by the nematode Haemonchus contortus, cause large economic losses to the producers, whether by complications of the diseases or the cost of treatment. The main way of handling nematodiasis is by administering anthelmintic drugs, but their excessive use has the disadvantage of causing drug resistance; therefore, an alternative is the use of herbal medicine for this purpose. Mesquite (Prosopis spp.) has been used in Mexico to treat gastrointestinal diseases attributed to helminths. The present study aimed to characterize the rheological properties of mesquite flour using the SeDeM Expert System to determine its suitability for tablet production by direct compression. Direct compression technology facilitates the tableting process by reducing manufacturing costs. The results of the present study indicate that mesquite flour can be processed by direct compression. The latter could allow the manufacturing of economic tablets to treat infections by H. contortus in ruminants.

High Antiparasitic and Antimicrobial Performance of Biosynthesized NiO Nanoparticles via Wasted Olive Leaf Extract

Background

Nowadays, recycling agricultural waste is of the utmost importance in the world for the production of valuable bioactive compounds and environmental protection. Olive leaf bioactive compounds have a significant potential impact on the pharmaceutical industry. These compounds possess remarkable biological characteristics, including antimicrobial, antiviral, anti-inflammatory, hypoglycemic, and antioxidant properties.

Methods

The present study demonstrates a green synthetic approach for the fabrication of nickel oxide nanoparticles (NiO-olive) using aqueous wasted olive leaf extract. Calcination of NiO-olive at 500°C led to the fabrication of pure NiO nanoparticles (NiO-pure). Different techniques, such as thermal gravimetric analysis (TGA), Fourier-transform infrared spectra (FTIR), ultraviolet-visible spectra (UV-Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM) fitted with energy-dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM), were used to characterize both NiO-olive and NiO-pure. The extract and nanoparticles were assessed for antiparasitic activity against adult ticks (Hyalomma dromedarii) and antimicrobial activity against Bacillus cereus, Pseudomonas aeruginosa, Aspergillus niger, and Candida albicans.

Results

From XRD, the crystal sizes of NiO-olive and NiO-pure were 32.94 nm and 13.85 nm, respectively. TGA, FTIR, and EDX showed the presence of olive organic residues in NiO-olive and their absence in NiO-pure. SEM and TEM showed an asymmetrical structure of NiO-olive and a regular, semi-spherical structure of NiO-pure. UV-Vis spectra showed surface plasmon resonance of NPs. Antiparasitic activity showed the highest mortality rate of 95% observed at a concentration of 0.06 mg/mL after four days of incubation. The antimicrobial activity showed the largest inhibition zone diameter of 33 ± 0.2 mm against the Candida albicans strain.

Conclusion

Nanoparticles of NiO-olive outperformed nanoparticles of NiO-pure and olive leaf extract in both antiparasitic and antimicrobial tests. These findings imply that NiO-olive may be widely used as an eco-friendly and effective antiparasitic and disinfection of sewage.

Ornidazole induced Stevens-Johnson syndrome without body surface involved: A case report

RATIONALE

Ornidazole is a synthetic nitroimidazole derivative that is commonly prescribed for antiparasitic or anti-anaerobic infections. It is generally well tolerated, with known side effects including gastrointestinal tract, anaphylaxis, and central nervous system reactions. Ornidazole-induced binocular reactive keratitis and several mucocutaneous lesions have been rarely reported.

PATIENT CONCERNS

A 52-year-old woman who suffered from vaginitis and received an ornidazole vaginal plug (0.5 g). Approximately 20 minutes after the suppository was inserted into the vagina, her lips were swollen and valva and labia were burning. Her eyes were red, sore, and watery.

DIAGNOSIS

She was diagnosed as Steven-Johnson syndrome by the ophthalmologist. According to the Naranjo scale, the adverse drug reaction was evaluated to be probable and severe.

INTERVENTIONS

Dexamethasone was intravenous administrated as anti-inflammatory therapy for 10 days. Eye drops were locally given to relieve edema and promote healing of the epithelium. The symptoms of her eyes, lips, vulva and crissum were soon relieved.

OUTCOMES

The patient was discharge from hospital with improved symptoms.

LESSONS

In order to avoid severe adverse effect, the patient should not use metronidazole ether orally or vaginally. The case emphasized the importance of rapid and accurate diagnosis of Steven-Johnson syndrome induced by ornidazole vaginal plug, especially when the eye symptoms were the chief complaint without body skin involved.

Beneficial Bacteria and Plant Extracts Promote Honey Bee Health and Reduce Nosema ceranae Infection

The research aims to give new insights on the effect of administering selected bacterial strains, isolated from honey bee gut, and/or a commercial plant extract blend (HiveAlive®) on Nosema ceranae. Analyses were first performed under laboratory conditions such as different infective doses of N. ceranae, the effect of single strains and their mixture and the influence of pollen administration. Daily survival and feed consumption rate were recorded and pathogen development was analysed using qPCR and microscope counts. Biomarkers of immunity and physiological status were also evaluated for the different treatments tested using one bacterial strain, a mixture of all the bacteria and/or a plant extract blend as treatments. The results showed an increase of abaecin transcript levels in the midgut of the honey bees treated with the bacterial mixture and an increased expression of the protein vitellogenin in the haemolymph of honey bees treated with two separate bacterial strains (Bifidobacterium coryneforme and Apilactobacillus kunkeei). A significant effectiveness in reducing N. ceranae was shown by the bacterial mixture and the plant extract blend regardless of the composition of the diet. This bioactivity was seasonally linked. Quantitative PCR and microscope counts showed the reduction of N. ceranae under different experimental conditions. The antiparasitic efficacy of the treatments at field conditions was studied using a semi-field approach which was adapted from research on insecticides for the first time, to analyse antiparasitic activity against N. ceranae. The approach proved to be reliable and effective in validating data obtained in the laboratory. Both the mixture of beneficial bacteria and its association with Hive Alive® are effective in controlling the natural infection of N. ceranae in honey bee colonies.

Molecular surveillance of Kelch 13 polymorphisms in Plasmodium falciparum isolates from Kenya and Ethiopia

BACKGROUND

Timely molecular surveillance of Plasmodium falciparum kelch 13 (k13) gene mutations is essential for monitoring the emergence and stemming the spread of artemisinin resistance. Widespread artemisinin resistance, as observed in Southeast Asia, would reverse significant gains that have been made against the malaria burden in Africa. The purpose of this study was to assess the prevalence of k13 polymorphisms in western Kenya and Ethiopia at sites representing varying transmission intensities between 2018 and 2022.

METHODS

Dried blood spot samples collected through ongoing passive surveillance and malaria epidemiological studies, respectively, were investigated. The k13 gene was genotyped in P. falciparum isolates with high parasitaemia: 775 isolates from four sites in western Kenya (Homa Bay, Kakamega, Kisii, and Kombewa) and 319 isolates from five sites across Ethiopia (Arjo, Awash, Gambella, Dire Dawa, and Semera). DNA sequence variation and neutrality were analysed within each study site where mutant alleles were detected.

RESULTS

Sixteen Kelch13 haplotypes were detected in this study. Prevalence of nonsynonymous k13 mutations was low in both western Kenya (25/783, 3.19%) and Ethiopia (5/319, 1.57%) across the study period. Two WHO-validated mutations were detected: A675V in three isolates from Kenya and R622I in four isolates from Ethiopia. Seventeen samples from Kenya carried synonymous mutations (2.17%). No synonymous mutations were detected in Ethiopia. Genetic variation analyses and tests of neutrality further suggest an excess of low frequency polymorphisms in each study site. Fu and Li's F test statistic in Semera was 0.48 (P > 0.05), suggesting potential population selection of R622I, which appeared at a relatively high frequency (3/22, 13.04%).

CONCLUSIONS

This study presents an updated report on the low frequency of k13 mutations in western Kenya and Ethiopia. The WHO-validated R622I mutation, which has previously only been reported along the north-west border of Ethiopia, appeared in four isolates collected from eastern Ethiopia. The rapid expansion of R622I across Ethiopia signals the need for enhanced monitoring of the spread of drug-resistant P. falciparum parasites in East Africa. Although ACT remains currently efficacious in the study areas, continued surveillance is necessary to detect early indicators of artemisinin partial resistance.

Green synthesis of silver and iron oxide nanoparticles mediated photothermal effects on Blastocystis hominis

The evolution of parasite resistance to antiparasitic agents has become a serious health issue indicating a critical and pressing need to develop new therapeutics that can conquer drug resistance. Nanoparticles are novel, promising emerging drug carriers that have demonstrated efficiency in treating many parasitic diseases. Lately, attention has been drawn to a broad-spectrum nanoparticle capable of converting absorbed light into heat via the photothermal effect phenomenon. The present study is the first to assess the effect of silver nanoparticles (Ag NPs) and iron oxide nanoparticles (Fe3O4 NPs) as sole agents and with the combined action of the light-emitting diode (LED) on Blastocystis hominins (B. hominis) in vitro. Initially, the aqueous synthesized nanoparticles were characterized by UV-Vis spectroscopy, zeta potential, and transmission electron microscopy (TEM). The anti-blastocyst efficiency of these NPs was tested separately in dark conditions. As these NPs have a wide absorption spectrum in the visible regions, they were also excited by a continuous wave LED of wavelength band (400-700 nm) to test the photothermal effect. The sensitivity of B. hominis cysts was evaluated using scanning laser confocal microscopy whereas the live and dead cells were accurately segmented based on superpixels and the k-mean clustering algorithm. Our findings showed that this excitation led to hyperthermia that induced a significant reduction in the number of cysts treated with photothermally active NPs. The results of this study elucidate the potential role of photothermally active NPs as an effective anti-blastocystis agent. By using this approach, new therapeutic antiparasitic agents can be developed.

Simultaneous determination of praziquantel, fipronil, eprinomectin, (S)-methoprene, their key related substances and butylated hydroxytoluene (BHT) in a topical veterinary drug product by a single stability indicating high performance liquid chromatography method

A simple, robust and QC (quality control) friendly high performance liquid chromatography (HPLC) method was developed and validated for simultaneous determination of four active pharmaceutical ingredient [namely fipronil, (S)-methoprene, eprinomectin, and praziquantel] and their key degradation products in a broad-spectrum topical finished product. Typical sample of the finished product contains a total of 30-plus peaks of interest. Analytes were separated on a HALO C18 column (150 mm × 4.6 mm i.d., 2.7 µm particle size) with a gradient elution at 50 °C column temperature and 0.6 mL/min flow rate. Detection wavelength of 245 nm is used for praziquantel, eprinomectin and their degradation products, 265 nm for (S)-methoprene and its degradation products and 280 nm for fipronil and its degradation products and for the antioxidant, BHT. Mobile phase of the method is composed of 10 mM potassium phosphate buffer and 1,4- Dioxane (98/2, v/v, pH 5.0) as mobile phase-A, and EtOH/MeOH/MeCN/IPA (86/4/6/4, v/v/v/v) as mobile phase-B. All analytes of interest were adequately separated by this single HPLC method. The stability-indicating capability of the method has been demonstrated by successfully separating the degradation products in the stressed degraded samples of the finished product. Limit of quantitation (LOQ) and limit of detection (LOD) of the method is 0.3% and 0.1% of target analytical concentration for each individual API in the finished product. This method has been demonstrated to be sensitive, robust, specific, accurate and stability-indicating for analysis of the topical drug product containing praziquantel, fipronil, eprinomectin and (S)-methoprene.

Chagas Disease Diagnostic Practices at Four Major Hospital Systems in California and Texas

BACKGROUND

Chagas disease (CD) is a parasitic disease that affects ∼300 000 people living in the United States. CD leads to cardiac and/or gastrointestinal disease in up to 30% of untreated people. However, end-organ damage can be prevented with early diagnosis and antiparasitic therapy.

METHODS

We reviewed electronic health records of patients who underwent testing for CD at four hospital systems in California and Texas between 2016 and 2020. Descriptive analyses were performed as a needs assessment for improving CD diagnosis.

RESULTS

In total, 470 patients were tested for CD. Cardiac indications made up more than half (60%) of all testing, and the most frequently cited cardiac condition was heart failure. Fewer than 1% of tests were ordered by obstetric and gynecologic services. Fewer than half (47%) of patients had confirmatory testing performed at the Centers for Disease Control and Prevention.

DISCUSSION

Four major hospitals systems in California and Texas demonstrated low overall rates of CD diagnostic testing, testing primarily among older patients with end-organ damage, and incomplete confirmatory testing. This suggests missed opportunities to diagnose CD in at-risk individuals early in the course of infection when antiparasitic treatment can reduce the risk of disease progression and prevent vertical transmission.

Total Synthesis of Cyanobactin Natural Product Balgacyclamide B

Balgacyclamide A-C are a family of cyanobactin natural products isolated from freshwater cyanobacteria Microcystis aeruginosa. These macrocyclic peptides are characterized by their oxazoline-thiazole core, their 7 or 8 stereocenters, and their antiparasitic activities. Balgacyclamide B is known for its activity towards Plasmodium falciparum chloroquine-resistant strain K1, Trypanosoma brucei rhodesiense, and Leishmania donovani. In this report, the first total synthesis of Balgacyclamide B is described in a 17-steps pathway and a 2 % overall yield. The synthetic pathway toward balgacyclamide B can be adapted for the future syntheses of balgacyclamide A and C. In addition, a brief history background of oxazolines syntheses is shown to emphasize the importance of the cyclization conditions used to interconvert or retain configuration of β-hydroxy amides via dehydrative cyclization.

Unusual parasitoses in urban dogs: Urinary capillariosis and linguatulosis, cases report

Parasitic diseases caused by uncommonly diagnosed parasites may pose a threat to companion animals' health in urban environments where they are least expected. The pentastomid Linguatula serrata (tongue worm) and the capillarid Pearsonema plica (syn. Capillaria plica) are parasites with an indirect life cycle, infecting both domestic and wild carnivores. The present report describes two cases: the first one of urinary capillariosis and the other of linguatulosis, in two dogs living in the urban environment of Athens, Greece. In the case of capillariosis, the dog never lived out of the city, so it was presumably infected in the urban environment. On the contrary, in the case of linguatulosis, the dog was adopted at a young age from a rural environment but remained asymptomatic for several months while living in the city. Both dogs had mild symptoms, compatible with these infections. Urinary capillariosis and linguatulosis are uncommon in owned, pet dogs, living in cities due to epizootiological characteristics, i.e. need for wildlife reservoir for P. plica and consumption of raw infected viscera for L. serrata. Different factors contribute to the fact that such infections may occur in scenarios where they are least expected. Recent studies show a progressive worldwide increase in the number of uncommon parasitoses in pet animals, that in some cases, such as linguatulosis, are of zoonotic relevance. Regular parasitological examinations and preventive antiparasitic schemes are necessary in order to treat and prevent infections in pet animals and safeguard the health of both animals and humans under the concept of One Health.

Madurastatins with Imidazolidinone Rings: Natural Products or Side-Reaction Products from Extraction Solvents?

Madurastatins are a group of pentapeptides containing an oxazoline moiety, and, in a few cases, an imidazolidinone ring as an additional structural feature. In our search for new potential antiparasitic metabolites from natural sources, we studied the acetone extracts from a culture of Actinomadura sp. CA-135719. The LC/HRMS analysis of this extract identified the presence of the known madurastatins C1 (1), D1 (4), and D2 (5) together with additional members of the family that were identified as the new madurastatins H2 (2) and 33-epi-D1 (3) after isolation and spectroscopic analysis. The planar structures of the new compounds were established by HRMS, ESI-qTOF-MS/MS, and 1D and 2D NMR data, and their absolute configuration was proposed using Marfey's and bioinformatic analyses of the biosynthetic gene cluster (BGC). A revision of the absolute configuration of madurastatins D1 and D2 is proposed. Additionally, madurastatins containing imidazolidinone rings are proved to be artifacts originating during acetone extraction of the bacterial cultures.

High-Throughput Phenotypic Screening and Machine Learning Methods Enabled the Selection of Broad-Spectrum Low-Toxicity Antitrypanosomatidic Agents

Broad-spectrum anti-infective chemotherapy agents with activity against Trypanosomes, Leishmania, and Mycobacterium tuberculosis species were identified from a high-throughput phenotypic screening program of the 456 compounds belonging to the Ty-Box, an in-house industry database. Compound characterization using machine learning approaches enabled the identification and synthesis of 44 compounds with broad-spectrum antiparasitic activity and minimal toxicity against Trypanosoma brucei, Leishmania Infantum, and Trypanosoma cruzi. In vitro studies confirmed the predictive models identified in compound 40 which emerged as a new lead, featured by an innovative N-(5-pyrimidinyl)benzenesulfonamide scaffold and promising low micromolar activity against two parasites and low toxicity. Given the volume and complexity of data generated by the diverse high-throughput screening assays performed on the compounds of the Ty-Box library, the chemoinformatic and machine learning tools enabled the selection of compounds eligible for further evaluation of their biological and toxicological activities and aided in the decision-making process toward the design and optimization of the identified lead.

Water pollution from pharmaceutical use in livestock farming: Assessing differences between livestock types and production systems

Livestock production is a major source of pharmaceutical emissions to the environment. The current scientific discourse focuses on measuring and modeling emissions as well as assessing their risks. Although several studies corroborate the severity of pharmaceutical pollution resulting from livestock farming, differences in pollution between livestock types and production systems are largely unknown. In fact, there is no comprehensive analysis of factors influencing pharmaceutical use-the emission's source-in the diverse production systems. To address these knowledge gaps, we developed a framework to investigate pharmaceutical pollution from different livestock production systems and applied it in a first pilot assessment to compare pollution from organic and conventional cattle, pig, and chicken production systems on selected indicator substances, covering antibiotics, antiparasitics, hormones, and nonsteroidal anti-inflammatory drugs (NSAIDs). Given the lack of statistics, for this article we retrieved novel qualitative information about influential factors for pharmaceutical use and pollution from expert interviews and combined this with quantitative data on, among other factors, the environmental behavior of specific substances from the literature. Our analysis reveals that factors across a pharmaceutical's entire life cycle influence pollution. However, not all factors are livestock type or production-system dependent. The pilot assessment furthermore reveals that differences in pollution potential between conventional and organic production exist, but for antibiotics, NSAIDs, and partially for antiparasitics, some factors lead to greater pollution potential in conventional systems, and others in organic systems. For hormones, we identified a comparatively greater pollution potential from conventional systems. Among the indicator substances, the assessment over the entire pharmaceutical life cycle illustrates that flubendazole in broiler production has the greatest per unit impact. The framework and its application in the pilot assessment generated insights useful to identifying which substances, livestock types, production systems, or the combination thereof have great or little pollution potential, informing more sustainable agricultural management practices. Integr Environ Assess Manag 2023;19:1495-1509. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Gametocyte prevalence and risk factors of P. falciparum malaria patients admitted at the Hospital for Tropical Diseases, Thailand: a 20-year retrospective study

BACKGROUND

The incidence of malaria in Thailand has dramatically declined over the past two decades, and the goal is to eliminate malaria by 2025. Despite significant progress, one of the key challenges to malaria elimination are undetected gametocyte carriers. Human migration adds complexity to the malaria situation, as it not only sustains local transmission but also poses the risk of spreading drug-resistant parasites. Currently, no study has assessed the prevalence of gametocytes across multiple years in Plasmodium falciparum malaria patients in Thailand, and the risk factors for gametocyte carriage have not been fully explored.

METHODS

Medical records of all P. falciparum malaria patients admitted from January 1, 2001 to December 31, 2020 at the Hospital for Tropical Diseases, Thailand, were retrospectively examined and a total of 1962 records were included for analysis. Both P. falciparum parasites and gametocytes were diagnosed by microscopy. A regression model was used to evaluate predictors of gametocyte carriage.

RESULTS

The study demonstrated gametocyte prevalence in low malaria transmission areas. Nine risk factors for gametocyte carriage were identified: age between 15 and 24 years [adjusted odds ratio (aOR) = 1.96, 95% confidence interval (CI) 1.18-3.26], Karen ethnicity (aOR = 2.59, 95% CI 1.56-4.29), preadmission duration of fever > 7 days (aOR = 5.40, 95% CI 3.92-7.41), fever on admission (> 37.5 °C) (aOR = 0.61, 95% CI 0.48-0.77), haemoglobin ≤ 8 g/dL (aOR = 3.32, 95% CI 2.06-5.33), asexual parasite density > 5000-25,000/µL (aOR = 0.71, 95% CI 0.52-0.98), asexual parasite density > 25,000-100,000/µL (aOR = 0.74, 95% CI 0.53-1.03), asexual parasite density > 100,000/µL (aOR = 0.51, 95% CI 0.36-0.72), platelet count ≤ 100,000/µL (aOR = 0.65, 95% CI 0.50-0.85, clinical features of severe malaria (aOR = 2.33, 95% CI 1.76-3.10) and dry season (aOR = 1.41, 95% CI 1.10-1.80). An increasing incidence of imported transnational malaria cases was observed over the past two decades.

CONCLUSIONS

This is the first study to determine the prevalence of gametocytes among patients with symptomatic P. falciparum malaria, identify the risk factors for gametocyte carriage, and potential gametocyte carriers in Thailand. Blocking transmission is one of the key strategies for eliminating malaria in these areas. The results might provide important information for targeting gametocyte carriers and improving the allocation of resources for malaria control in Thailand. This study supports the already nationally recommended use of a single dose of primaquine in symptomatic P. falciparum malaria patients to clear gametocytes.

Activity of compounds derived from benzofuroxan in Trichomonasvaginalis

Trichomoniasis is a sexually transmitted infection caused by the protozoan Trichomonas vaginalis. Currently, trichomoniasis is treated with the class of nitroimidazoles, namely, metronidazole; however, resistant isolates and strains have been reported. The compounds derived from benzofuroxan are biologically active heterocycles. This study evaluated the in vitro antiparasitic activity of these compounds in trophozoites of T. vaginalis and determined the mean inhibitory concentration (IC50), minimum inhibitory concentration (MIC), mortality curve, and cytotoxicity. The compounds were named EH1, EH2, EH3, and EA2 and tested in various concentrations: 100 to 15 μM (EH1 and EH2); 100 to 5 μM (EH3); and 100 to 25 μM (EA2), respectively. The greatest efficacy was observed in the highest concentrations in 24 h, with inhibition of approximately 100% of trophozoites. Compounds EH2 and EH3 had the lowest MIC: EH2 (35 μM) and EH3 (45 μM), with IC50 of 11.33 μM and 6.83 μM, respectively. Compound EA2 was effective at the highest concentrations. The activity of the compounds in T. vaginalis started in the first hour of incubation with 90% inhibition; after 12 h, inhibition >95% was observed. Compound EH1 showed the lowest activity, with the highest activity between 12 and 24 h after incubation. These results demonstrate that benzofuroxan derivatives are promising compounds for the in vitro treatment of T. vaginalis.

Praziquantel meets Niclosamide: A dual-drug Antiparasitic Cocrystal

In this paper we report a successful example of combining drugs through cocrystallization. Specifically, the novel solid is formed by two anthelminthic drugs, namely praziquantel (PZQ) and niclosamide (NCM) in a 1:3 molar ratio, and it can be obtained through a sustainable one-step mechanochemical process in the presence of micromolar amounts of methanol. The novel solid phase crystallizes in the monoclinic space group of P21/c, showing one PZQ and three NCM molecules linked through homo- and heteromolecular hydrogen bonds in the asymmetric unit, as also attested by SSNMR and FT-IR results. A plate-like habitus is evident from scanning electron microscopy analysis with a melting point of 202.89 °C, which is intermediate to those of the parent compounds. The supramolecular interactions confer favorable properties to the cocrystal, preventing NCM transformation into the insoluble monohydrate both in the solid state and in aqueous solution. Remarkably, the PZQ - NCM cocrystal exhibits higher anthelmintic activity against in vitro S. mansoni models than corresponding physical mixture of the APIs. Finally, due to in vitro promising results, in vivo preliminary tests on mice were also performed through the administration of minicapsules size M.

Emerging alternatives to traditional anthelmintics: the in vitro antiparasitic activity of silver and selenium nanoparticles, and pomegranate (Punica granatum) peel extract against Haemonchus contortus

Haemonchus contortus (H. contortus) is one of the most prevalent gastrointestinal nematodes, causing health problems and economic losses in ruminants. Nanotechnology holds great promise as a field of science, with potential applications in veterinary medicine. This study investigated the in vitro anthelmintic activity of silver nanoparticles (AgNPs), selenium nanoparticles (SeNPs), and pomegranate peel extract (Punica granatum; PPE) on different stages of H. contortus: eggs, larvae, and adults. The in vitro anthelmintic efficacy was evaluated using the egg hatching inhibition assay (EHA), the third larval stage paralysis assay (LPA), and the adult worm motility inhibition assay (WMI). Six dilutions of PPE were utilized for EHA, LPA, and WMI, ranging from 0.25 to 6 mg/ml. AgNPs dilutions ranged from 0.00001 to 1.0 μg/ml for EHA and LPA and 1 to 25 μg/ml for WMI. SeNPs were utilized at dilutions of 1, 5, 10, and 15 μg/ml for EHA, LPA, and WMI. The results showed that the lowest concentration of AgNPs, SeNPs, and PPE significantly inhibited egg hatching. To further assess larvicidal activity, AgNPs at the highest concentration of 1 μg/ml induced a strong larvicidal effect, as did SeNPs at the lowest concentration. On the contrary, PPE displayed a significant larvicidal effect at 1 mg/ml compared to the control. The percentage mortality of adult H. contortus was measured as follows (mortality (%) = the number of dead adult H. contortus/total number of adult H. contortus per test × 100). The death of the adult H. contortus was determined by the absence of motility. Adult H. contortus mortality percentage was also significantly affected by all three agents when compared to the control. The AgNPs, SeNPs, and PPE have effective antiparasitic activity on gastrointestinal parasitic nematodes. These results provide evidence of the excellent antiparasitic properties of AgNPs, SeNPs, and PPE, demonstrating their effectiveness in controlling eggs, larvae, and adult H. contortus in vitro.

Design and development of new inhibitors against breast cancer, Monkeypox and Marburg virus by modification of natural Fisetin via in silico and SAR studies

The natural Fisetin and its derivatives have been shown to have effective bioactivity and strong pharmacological profile, which is continuously drawing the interest of therapeutic applications to the development of new biomolecules against Breast cancer and Monkeypox, and Marburg viral infection, while computational approaches and the study of their structure-activity relationship (SAR) are the most eloquent and reliable platform for performing their hypothetical profile renovation. So, the main perspective of this investigation is to evaluate dual function of Fisetin and its derivatives against both virus and cancerous target. First and foremost, the prediction of activity spectra for materials (PASS) valuation has provided preliminary data on the antiviral, antibacterial, antiparasitic, and anti-cancer possibilities of the mentioned compounds. According to the evidence, PASS predicted scores were shown to perform better in antineoplastic and antiviral than antibacterial, and antiparasitic efficiency; as evidenced by their higher PASS scores in antineoplastic and antiviral drug tests. Breast cancer, Monkeypox, and Marburg virus have been selected as targeted pathogens, and different in silico studies were conducted to determine the dual function of mention derivatives. The "Lipinski five rules," on the other hand, has been subjected to extensive testing for drug-like characteristics. Molecular docking against Breast cancer, Monkeypox, and Marburg virus have been accomplished after confirmation of their bioactivity. The molecular docking evaluation against targeted disease displayed re-markable binding affinity and non-bonding engagement, with most of the results indicating that derivatives are more effective than the FDA approved standard antiviral, and antineoplastic drugs. Finally, the ADMET characteristics have been computed, and they indicate that the substance is suitable to use and did not have any chance to produce adverse effects on aquatic or non-aquatic environment, as well as having a highly soluble capacity in water medium, high G.I absorption rate, with outstanding bioavailability index. Therefore, these mentioned Fisetin derivatives could be suggested as potential medication against Breast cancer and newly reported Monkeypox, and Marburg virus, and may further proceed for laboratory experiment, synthesis, and clinical trials to evaluate their practical value.

Efficacy of Carapa guianensis oil (Meliaceae) against monogeneans infestations: a potential antiparasitic for Colossoma macropomum and its effects in hematology and histopathology of gills

This study evaluated the efficacy of therapeutic baths with Carapa guianensis (andiroba) oil against monogeneans of Colossoma macropomum (tambaqui), as well as the hematological and histological effects on fish. Among the fatty acids identified in C. guianensis oil, oleic acid (53.4%) and palmitic acid (28.7%) were the major compounds, and four limonoids were also identified. Therapeutic baths of 1 hour were performed for five consecutive days, and there was no fish mortality in any of the treatments. Therapeutic baths using 500 mg/L of C. guianensis oil had an anthelmintic efficacy of 91.4% against monogeneans. There was increase of total plasma protein and glucose, number of erythrocytes, thrombocytes, leukocytes, lymphocytes and number of monocytes and decrease in mean corpuscular volume. Histological changes such as epithelium detachment, hyperplasia, lamellar fusion and aneurysm were found in the gills of tambaqui from all treatments, including controls with water of culture tank and water of culture tank plus iso-propyl alcohol. Therapeutic baths with 500 mg/L of C. guianensis oil showed high efficacy and caused few physiological changes capable of compromising fish gill function. Results indicate that C. guianensis oil has an anthelmintic potential for control and treatment of infections by monogeneans in tambaqui.

Evaluation of PEN2-ATP6AP1 axis as an antiparasitic target for metformin based on phylogeny analysis and molecular docking

BACKGROUND

Metformin (Met), the first-line drug used in the treatment for type 2 diabetes mellitus, is effective against a variety of parasites. However, the molecular target of Met at clinical dose against various parasites remains unclear. Recently, low-dose Met (clinical dose) has been reported to directly bind PEN2 (presenilin enhancer protein 2) and initiate the lysosomal glucose-sensing pathway for AMPK activation via ATP6AP1 (V-type proton ATPase subunit S1), rather than perturbing AMP/ATP levels.

METHODS

To explore the possibility of PEN2-ATP6AP1 axis as a drug target of Met for the treatment of parasitic diseases, we identified and characterized orthologs of PEN2 and ATP6AP1 genes in parasites, by constructing phylogenetic trees, analyzing protein sequences and predicting interactions between Met and parasite PEN2.

RESULTS

The results showed that PEN2 and ATP6AP1 genes are only found together in a few of parasite species in the cestoda and nematoda groups. Indicated by molecular simulation, Met might function by interacting with PEN2 on V37/W38/E5 (Trichinella spiralis) with similar binding energy, and on F35/S39 (Caenorhabditis elegans) with higher binding energy, comparing to human PEN2. Hence, these results indicated that only the T. spiralis PEN2-ATP6AP1 axis has the potential to be the direct target of low-concentration Met. Together with contribution of host cells including immune cells in vivo, T. spiralis PEN2-ATP6AP1 axis might play roles in reducing parasite load at low-concentration Met. However, the mechanisms of low-concentration Met on other parasitic infections might be mainly achieved by regulating host cells, rather than directly targeting PEN2-ATP6AP1 axis.

CONCLUSIONS

These findings revealed the potential mechanisms by which Met treats various parasitic diseases, and shed new light on the development of antiparasitic drugs.

Perspectives on Saponins: Food Functionality and Applications

Saponins are a diverse group of naturally occurring plant secondary metabolites present in a wide range of foods ranging from grains, pulses, and green leaves to sea creatures. They consist of a hydrophilic sugar moiety linked to a lipophilic aglycone, resulting in an amphiphilic nature and unique functional properties. Their amphiphilic structures enable saponins to exhibit surface-active properties, resulting in stable foams and complexes with various molecules. In the context of food applications, saponins are utilized as natural emulsifiers, foaming agents, and stabilizers. They contribute to texture and stability in food products and have potential health benefits, including cholesterol-lowering and anticancer effects. Saponins possess additional bioactivities that make them valuable in the pharmaceutical industry as anti-inflammatory, antimicrobial, antiviral, and antiparasitic agents to name a few. Saponins can demonstrate cytotoxic activity against cancer cell lines and can also act as adjuvants, enhancing the immune response to vaccines. Their ability to form stable complexes with drugs further expands their potential in drug delivery systems. However, challenges such as bitterness, cytotoxicity, and instability under certain conditions need to be addressed for effective utilization of saponins in foods and related applications. In this paper, we have reviewed the chemistry, functionality, and application aspects of saponins from various plant sources, and have summarized the regulatory aspects of the food-based application of quillaja saponins. Further research to explore the full potential of saponins in improving food quality and human health has been suggested. It is expected that this article will be a useful resource for researchers in food, feed, pharmaceuticals, and material science.

A nationwide serological survey for Dirofilaria immitis in companion cats in the United States of America: 3.5% antibody and 0.3% antigen positivity

BACKGROUND

Feline heartworm disease (HWD) is a complex and often misdiagnosed disease in cats, caused by the filarial nematode Dirofilaria immitis. Despite its significant impact, studies reporting the prevalence of D. immitis in apparently healthy pet cats in the USA are lacking.

METHODS

To investigate feline heartworm seroprevalence in apparently healthy pet cats in the USA, serum samples (n = 2165) collected from cats across 47 states and Washington District of Columbia were analyzed for D. immitis antibody (Heska Corp.) and antigen (DiroCHEK®; Zoetis Inc.) with and without acid treatment of the samples.

RESULTS

Antibodies to D. immitis antibodies were identified in 3.5% (76/2165) of cats from 26 states, with a significantly higher prevalence in cats from the westernmost US states (West region; 5.4%, 23/429) compared to those from the South (3.8%, 32/847), Midwest (2.7%, 9/338) and Northeast regions (2.2%, 12/551) (P < 0.04). Antigen from D. immitis was detected in 0.3% (6/2165) of cats, which was significantly lower than the antibody detection (P < 10-4), and no samples were positive for both antibody and antigen.

CONCLUSIONS

This is the largest antibody-based, nationwide serosurvey of feline heartworm in an apparently healthy cat population, and the results suggest that cats in the USA have a high risk of exposure to D. immitis-infected mosquitoes. The high nationwide prevalence (3.5%) indicates that the true prevalence of cats infected with D. immitis in the USA may be significantly underestimated. Our findings emphasize the need for increased awareness and routine testing of cats for heartworm infection, especially in non-endemic areas of the USA. Clinicians should consider appropriate use of broad-spectrum veterinary-approved parasiticides and lifestyle management in feline patients to reduce the risk of infection. Future studies should focus on evaluating the D. immitis infection status in healthy cats and developing better diagnostic assays to detect this complex infection.

In vitro and in vivo Efficacies of Novel Harmine Derivatives in the Treatment of Cystic Echinococcosis

Introduction

Cystic echinococcosis (CE) is a chronic zoonotic parasitic disease caused by the larvae of the Echinococcus granulosus sensu lato (s.l.) cluster. The current existing drugs have limited therapeutic efficacy against cystic echinococcosis, and thus, there is an urgent need to develop new drugs.

Methods

In this study, 7 harmine (HM) derivatives were screened and the effects of HM derivatives on E. granulosus sensu stricto (s.s.) were evaluated by in vitro and mouse experiments. The safety of the HM derivatives was assessed by cytotoxicity assays, acute toxicity study in animals and subacute toxicity study.

Results

These results show that the HM derivatives H-2-168 and DH-004 exhibited more significant antiparasitic effects at an initial concentration of 40 μM. The results of further studies showed that H-2-168 and DH-004 had dose-dependent effects against protoscoleces and had satisfactory therapeutic outcomes in vivo. Electron microscopy observations demonstrated that H-2-168 and DH-004 caused severe disruption of the parasite ultrastructure. Notably, the results of the acute toxicity and subchronic toxicity studies showed that H-2-168 and DH-004 had significantly improved safety. In addition, we found that H-2-168 and DH-004 induced DNA damage in E. granulosus s.s., which may be the mechanism by which these drugs produce their therapeutic effects.

Discussion

Overall, the data from this work demonstrate that H-2-168 and DH-004 are highly effective candidate compounds with low toxicity for the treatment of CE and will provide a new therapeutic strategy for CE pharmacological treatment.

Acaricidal efficacy evaluation of amitraz and diazinon against Amblyomma variegatum tick species in Waghimra zone, northern Ethiopia

Ticks pose a substantial economic burden associated with production loss and treatment costs globally. Ethiopia has tremendous livestock resources, but its productivity is hindered by various animal health challenges in which ticks are the top priority, with a limited response to acaricidal treatments. Hence, we designed an acaricidal efficacy trial for the top commercially available Chemicals (amitraz and diazinon) to examine their efficacy against the widely distributed tick species (Amblyoma variegatum). Ticks were collected from animals admitted to veterinary clinics with no history of treatment with acaricides. Adult Immersion Technique (AIT) was employed to detect acaricidal resistance, and the mean percent control and antiparasitic efficacy were used to estimate tick susceptibility with a completely randomized laboratory-based trial (CRT). The mean weights of eggs laid by ticks subjected to amitraz and diazinon indicated that amitraz had a better egg-laying-inhibition effect than diazinon. The mean control percentages of amitraz and diazinon were 92.8 ± 5.6% and 69.7 ± 3.1%, respectively, with a highly significant difference (P-value = 0.00). The antiparasitic efficacy of the two drugs was 57.5 ± 0.96 and 37.5% ± 0.96 for amitraz and diazinon, respectively, which revealed that amitraz was statistically better than diazinon in killing adult ticks (P-value =0.026). In general, ticks treated with diazinon showed evidence of resistance development, and amitraz is relatively the most effective acaricide; we recommend its use in the study area and other locations with similar settings.

Cryptosporidium parvum hijacks a host's long noncoding RNA U90926 to evade intestinal epithelial cell-autonomous antiparasitic defense

Cryptosporidium is a zoonotic apicomplexan parasite that infects the gastrointestinal epithelium and other mucosal surfaces in humans. It is an important opportunistic pathogen in AIDS patients and a leading cause of infectious diarrhea and diarrheal-related death in children worldwide. The intestinal epithelial cells provide the first line of defense against Cryptosporidium infection and play a central role in activating and regulating the host's antiparasitic response. Increasing evidence suggests that long noncoding RNAs (lncRNAs) participate in host-pathogen interactions and play a regulatory role in the pathogenesis of diseases but the underlying molecular mechanisms are not fully understood. We previously identified a panel of host lncRNAs that are upregulated in murine intestinal epithelial cells following Cryptosporidium infection, including U90926. We demonstrate here that U90926 is acting in a pro-parasitic manner in regulating intestinal epithelial cell-autonomous antiparasitic defense. Inhibition of U90926 resulted in a decreased infection burden of the parasite while overexpression of U90926 showed an increase in infection burden in cultured murine intestinal epithelial cells. Induction of U90926 suppressed transcription of epithelial defense genes involved in controlling Cryptosporidium infection through epigenetic mechanisms. Specifically, transcription of Aebp1, which encodes the Aebp1 protein, a potent modulator of inflammation and NF-κB signaling, was suppressed by U90926. Gain- or loss-of-function of Aebp1 in the host's epithelial cells caused reciprocal alterations in the infection burden of the parasite. Interestingly, Cryptosporidium carries the Cryptosporidium virus 1 (CSpV1), a double-stranded (ds) RNA virus coding two dsRNA fragments, CSpV1-dsRdRp and CSpV1-dsCA. Both CSpV1-dsRdRp and CSpV1-dsCA can be delivered into infected cells as previously reported. We found that cells transfected with in vitro transcribed CSpV1-dsCA or CSpV1-dsRdRp displayed an increased level of U90926, suggesting that CSpV1 is involved in the upregulation of U90926 during Cryptosporidium infection. Our study highlights a new strategy by Cryptosporidium to hijack a host lncRNA to suppress epithelial cell-autonomous antiparasitic defense and allow for a robust infection.

Foetidumins A-D, and other chemical constituents from Helichrysum foetidum (L.) Moench (Asteraceae) with antiparasite activity

The phytochemical investigation of the MeOH and CH₂Cl₂-MeOH (1:1) extracts from the flowers and twigs of Helichrysumfoetidum (L.) Moench (Asteraceae), which showed antileishmanial and antiplasmodial activities during the preliminary screening, led to the isolation of four undescribed compounds, including two ent-beyer-15-ene-type diterpenoids, foetidumins A (1) and B (2), one flavonoid, foetidumin C (3) and one chalcopyrone, foetidumin D (4). Additionally, fourteen known compounds comprising, two ent-beyer-15-ene-type diterpenoids (5-6), six flavonoids (7-12), two steroids (13-14), three triterpenoids (15-17), and one glyceryl monostearate (18) were also isolated. The chemical structures of foetidumins A-D were fully elucidated by analyses of their spectroscopic data. The structure and the stereochemistry of foetidumin A (1) were confirmed by SC-XRD analyses. Among the tested compounds, foetidumin C (3), erythroxylol A (6), and kaempferol (7) displayed the highest antileishmanial potency with IC₅₀ values of 13.0, 11.8, and 11.1 μM, respectively. Foetidumin C (3) had no cytotoxicity toward Vero cells with the selectivity index > 3.59. Meanwhile, extracts of flowers and twigs had higher activity against Plasmodium falciparum chloroquine-sensitive (Pf3D7) strain with IC₅₀ values of 3.66 and 10.52 μg/mL, respectively.

Ivermectin bioaccumulation and transfer through developmental stages in Culex pipiens (Diptera: Culicidae)

Ivermectin (IVM), one of the most widely used antiparasitics in livestock, could enters into the aquatic environment because the treated animal metabolizes only a small percentage of what is administered and the rest is eliminated through the feces, largely as a parent drug, imposing a risk to aquatic organisms. The aims of this study were to (1) assess the effect of IVM spiked in cattle dung on the survival and emergence of Culex pipiens (Diptera: Culicidae), and to (2) evaluate the accumulation of this drug in the different developmental stages of this taxon. Larvae were exposed to two IVM concentrations (T1: 1000 ng g^-1 and T2: 500 ng g^-1) for 9 days. At days 3, 6 and 9 survival and adult emergence were recorded and samples of larvae, pupae, pupal exuviae and adults were taken to analyze the IVM accumulation. At these concentrations, a reduction in survival and adult emergence of C. pipiens was recorded. In addition, the IVM accumulation was observed in all samples analyzed, decreasing it throughout the development of this taxon (larvae > pupae > adults). Although a large proportion of the drug was lost during the metamorphosis, being mainly eliminated through pupal exuviae during molting, this process is not enough to eliminate it completely. Thus, part of the drug was transferred to the adult stage and remains available to the aquatic and terrestrial food webs. These results show that IVM represents a risk to aquatic invertebrates and their predators, which deserves further studies, especially in the context of their bioaccumulation and biomagnification through the aquatic and terrestrial trophic webs.

Sustainable development of factory aquaculture through automation of ultraviolet parasiticide for the prevention and control of cryptocaryoniasis

BACKGROUND

Cryptocaryon irritans infestations on marine teleosts are a considerable burden on factory mariculture. Ultraviolet (UV) light can kill C. irritans under laboratory conditions. However, a rational method for using UV in factory aquaculture to control cryptocaryoniasis has not been developed. This study focused on evaluating the killing effect of UV on protomonts and tomonts of C. irritans and established an automatic UV parasiticide device for the prevention and control of cryptocaryoniasis in marine teleosts.

RESULTS

The survival rate of protomonts and tomonts decreased with an increase in the UV irradiation dose. All the protomonts and tomonts died within 14 and 24 min, respectively. The lowest UV lethal doses of protomonts and tomonts of C. irritans were 2.0 × 10⁶ and 3.5 × 10⁶  μWs cm^-2 , respectively. Exposure of protomonts and tomonts to lethal doses of UV radiation led to shrinkage and severe dissolution of the protoplasm, causing abnormal development of cells. The survival rate of artificially infected Larimichthys crocea (treatment group, group A) was 83.33% at the end of the test (day 14) after disinfection using the automatic UV parasiticide device, whereas that of the control group (group C) was 90.00% (p < 0.05). However, all artificially infected L. crocea without disinfection using the automatic UV parasiticide device (untreated group, group B) died on day 8.

CONCLUSION

The automation of traditional physical methods conforms to the sustainable development of aquaculture and provides a theoretical reference for the prevention and control of cryptocaryoniasis in mariculture. © 2022 Society of Chemical Industry.

A review on the ecotoxicity of macrocyclic lactones and benzimidazoles on aquatic organisms

Despite its wide production and several applications, veterinary antiparasitics from macrocyclic lactones and benzimidazole classes have not received much scientific attention concerning their environmental risks. Thus, we aimed to provide insights into the state of the environmental research on macrocyclic lactone and benzimidazole parasiticides, emphasizing their toxicity to non-target aquatic organisms. We searched for relevant information on these pharmaceutical classes on PubMed and Web of Science. Our search yielded a total of 45 research articles. Most articles corresponded to toxicity testing (n = 29), followed by environmental fate (n = 14) and other issues (n = 2) of selected parasiticides. Macrocyclic lactones were the most studied chemical group (65% of studies). Studies were conducted mainly with invertebrate taxa (70%), with crustaceans being the most predominant group (n = 27; 51%). Daphnia magna was the most used species (n = 8; 15%). Besides, it also proved to be the most sensitive organism, yielding the lowest toxicity measure (EC₅₀ 0.25 μg/L for decreased mobility after 48 h-abamectin exposure) reported. Moreover, most studies were performed in laboratory settings, tracking a limited number of endpoints (acute mortality, immobility, and community disturbance). We posit that macrocyclic lactones and benzimidazoles warrant coordinated action to understand their environmental risks.

Spot-on thinking about parasite control

Is it time the veterinary profession took a step back from advising year-round, blanket prophylactic parasiticide treatment of companion animals and moved towards an individual animal, risk-based approach? Martin Whitehead thinks so, and at BVA Live he will discuss some of the reasons why.

Cryptosporidium uses CSpV1 to activate host type I interferon and attenuate antiparasitic defenses

Cryptosporidium infects gastrointestinal epithelium and is a leading cause of infectious diarrhea and diarrheal-related death in children worldwide. There are no vaccines and no fully effective therapy available for the infection. Type II and III interferon (IFN) responses are important determinants of susceptibility to infection but the role for type I IFN response remains obscure. Cryptosporidium parvum virus 1 (CSpV1) is a double-stranded RNA (dsRNA) virus harbored by Cryptosporidium spp. Here we show that intestinal epithelial conditional Ifnar1^-/- mice (deficient in type I IFN receptor) are resistant to C. parvum infection. CSpV1-dsRNAs are delivered into host cells and trigger type I IFN response in infected cells. Whereas C. parvum infection attenuates epithelial response to IFN-γ, loss of type I IFN signaling or inhibition of CSpV1-dsRNA delivery can restore IFN-γ-mediated protective response. Our findings demonstrate that type I IFN signaling in intestinal epithelial cells is detrimental to intestinal anti-C. parvum defense and Cryptosporidium uses CSpV1 to activate type I IFN signaling to evade epithelial antiparasitic response.

Antiparasitic effect of copper alloy mesh on tomont stage of Cryptocaryon irritans in aquaculture

Copper alloy sheets have been shown to prevent cryptocaryoniasis. Therefore, we studied the potential efficiency of copper alloy mesh (CAM) in aquaculture tanks to prevent cryptocaryoniasis outbreaks. The effectivenesses of CAM against the tomont stage of Cryptocaryon irritans and in protecting fish from cryptocaryoniasis were tested both in vitro and in vivo. The mortality rate of C. irritans tomonts increased as the contact time with CAM rose and peaked at 70 min (100% of mortality). Morphological changes were observed such as the shrinking of the protoplasm of the treated tomonts, resulting in a larger gap between the cytoplasm and the cyst wall. Mitochondrial dysfunction due to shrinkage in the inner portion, outer and inner mitochondrial membrane damage and cytoplasmic vacuolation was revealed by ultrastructural analysis. The use of CAM effectively preventing reinfection was also provided. In comparison with group B (infected fish without CAM), both groups A (uninfected fish as a control group) and C (infected fish treated with CAM) had a 100% survival rate until the end of the trial. CAM has the same anticryptocaryoniasis effect as copper alloy sheets but is more advantageous due to its lightweight, reduced labor cost and lower purchase cost. It is noticeable that CAM exposure also prevents the excessive accumulation of copper ions in aquaculture sea water.

Metabolization of emamectin benzoate into desmethyl emamectin benzoate in spiked marine sediments

Emamectin benzoate (EMB) (4″deoxy- 4″-epi-methylaminoavermectin) is a pesticide developed to control pests on various crops, and in forestry. It is also used in salmon aquaculture to control sea lice infestations as an in-feed therapeutant. Little is known about EMB metabolites and potential associated toxicities in marine sediments. In this study, we used natural marine sediments (sand and mud) fortified at an EMB concentration of 60 ppb (wet weight). Results show an almost immediate transformation of EMB to Desmethyl EMB (DES) with no increased rates of metabolization when stored sediment samples were incubated for up to 16 h. The transformation ratio of EMB to DES represented between 0.16 and 0.39% of EMB; values are lower than what has been observed in fish tissue. Data suggest that DES is generated through both abiotic (tested after autoclaving marine sediments) and biological processes. Further work on freshly sampled marine sediments with EMB deposits, different organic regimes, and a detailed assessment of active bacterial communities are necessary to better evaluate the EMB to DES rate of transformation around aquaculture sites.

Emerging Perspectives on the Antiparasitic Mebendazole as a Repurposed Drug for the Treatment of Brain Cancers

Repurposing approved non-antitumor drugs is a promising and affordable strategy in drug discovery to identify new therapeutic uses different from the original medical indication that may help increase the number of possible, effective anticancer drugs. The use of drugs in ways other than their original FDA-approved indications could offer novel avenues such as bypassing the chemoresistance and recurrence seen with conventional therapy and treatment; moreover, it can offer a safe and economic strategy for combination therapy. Recent works have demonstrated the anticancer properties of the FDA-approved drug Mebendazole. This synthetic benzimidazole proved effective against a broad spectrum of intestinal Helminthiasis. Mebendazole can penetrate the blood-brain barrier and has been shown to inhibit the malignant progression of glioma by targeting signaling pathways related to cell proliferation, apoptosis, or invasion/migration, or by increasing the sensitivity of glioma cells to conventional chemotherapy or radiotherapy. Moreover, several preclinical models and ongoing clinical trials explore the efficacy of Mebendazole in multiple cancers, including acute myeloid leukemia, brain cancer, oropharyngeal squamous cell carcinoma, breast cancer, gastrointestinal cancer, lung carcinoma, adrenocortical carcinoma, prostate cancer, and head and neck cancer. The present review summarizes central literature regarding the anticancer effects of MBZ in cancer cell lines, animal tumor models, and clinical trials to suggest possible strategies for safe and economical combinations of anticancer therapies in brain cancer. Mebendazole might be an excellent candidate for the treatment of brain tumors because of its efficacy both when used as monotherapy and in combination as an enhancement to standard chemotherapeutics and radiotherapy, due to its effectiveness on tumor angiogenesis inhibition, cell cycle arrest, apoptosis induction, and targeting of critical pathways involved in cancer such as Hedgehog signaling. Therefore, attention to MBZ repurposing has recently increased because of its potential therapeutic versatility and significant clinical implications, such as reducing medical care costs and optimizing existing therapies. Using new treatments is essential, particularly when current therapeutics for patients with brain cancer fail.

Toxocarosis in humans: how much of a problem is it in the UK?

Toxocara canis (from dogs) is recognised as a potential cause of human toxocarosis, but Toxocara cati (from cats) and other species (eg, Toxascaris leonina found in foxes) are also possible causes. Most colonisation with Toxocara species does not lead to symptomatic infection in well-cared for adult animals; young and debilitated animals are at greater risk. Humans can acquire infection from infected animals, for example, via soil contaminated with faeces; however, most human infections are asymptomatic, with symptomatic infection being very rare in the UK. The risk of human infection is reduced by measures such as hand washing and responsible disposal of dog faeces. Some organisations recommend regular prophylactic treatment of pet dogs and cats. However, there are concerns that some parasiticides are contaminating the environment. As an example of a One-Health problem there is a potential conflict between the needs of animal health, human health and the health of the wider ecosystem. Also, considering that only about 5% of non-juvenile household dogs shed Toxocara eggs at a given time, it has been questioned whether it is worthwhile to invest in frequent blind treatments. British veterinary organisations have suggested less frequent treatment may be more appropriate and should be based on individual risk assessment and faecal examinations for worms rather than blanket regular prophylactic treatment, which could reduce the impact of parasiticides on the environment without greatly increasing the risks to animal or human health.

Antiparasitic Activity of Compounds Isolated from Ganoderma tuberculosum (Agaricomycetes) from Mexico

The genus Ganoderma has a long history of use in traditional Asiatic medicine due to its different nutritional and medicinal properties. In Mexico, the species G. tuberculosum is used in indigenous communities, for example, the Wixaritari and mestizos of Villa Guerrero Jalisco for the treatment of diseases that may be related to parasitic infections; however, few chemical studies corroborate its traditional medicinal potential. Thereby, the objective of this study was to isolate and identify anti-parasitic activity compounds from a strain of G. tuberculosum native to Mexico. From the fruiting bodies of G. tuberculosum (GVL-21) a hexane extract was obtained which was subjected to guided fractioning to isolate pure compounds. The in vitro anti-parasitic activity of the pure compound (IC50) was assayed against Leishmania amazonensis, Trypanosoma cruzi, Acanthamoeba castellanii Neff, and Naegleria fowleri. Furthermore, the cytotoxicity (CC50) of the isolated compounds was determined against murine macrophages. The guided fractioning produced 5 compounds: ergosterol (1), ergosta-4,6,8(14),22-tetraen-3-one (2), ergosta-7,22-dien-3β-ol (3), 3,5-dihydroxy-ergosta-7,22-dien-6-one (4), and ganoderic acid DM (5). Compounds 2 and 5 showed the best anti-parasitic activity in an IC50 range of 54.34 ± 8.02 to 12.38 ± 2.72 µM against all the parasites assayed and low cytotoxicity against murine macrophages. The present study showed for the first time the in vitro anti-parasitic activity of compounds 1-5 against L. amazonensis, T. cruzi, A. castellanii Neff, and N. fowleri, corroborating the medicinal potential of Ganoderma and its traditional applications.

Asian Ancistrocladus Lianas as Creative Producers of Naphthylisoquinoline Alkaloids

This book describes a unique class of secondary metabolites, the mono- and dimeric naphthylisoquinoline alkaloids. They occur in lianas of the paleotropical Ancistrocladaceae and Dioncophyllaceae families, exclusively. Their unprecedented structures include stereogenic centers and rotationally hindered, and thus likewise stereogenic, axes. Extended recent investigations on six Ancistrocladus species from Asia, as reported in this review, shed light on their fascinating phytochemical productivity, with over 100 such intriguing natural products. This high chemodiversity arises from a likewise unique biosynthesis from acetate-malonate units, following a novel polyketidic pathway to plant-derived isoquinoline alkaloids. Some of the compounds show most promising antiparasitic activities. Likewise presented are strategies for the regio- and stereoselective total synthesis of the alkaloids, including the directed construction of the chiral axis.

Role of Nanomedicines in Controlling Malaria: A Review

Malaria has created havoc since time immemorial. It has actually become a major health concern due to its high prevalence in developing countries where poor sanitary conditions facilitate the seasonal breeding of the vector, the female Anopheles mosquito. Even after tremendous advancements in pest control and pharmacology science, managing this disease has not been successful, and the cure for this deadly infection has not proven effective lately. The various conventional drugs used are chloroquine, primaquine, mefloquine, atovaquone, quinine, artemisinin etc. All of these have one or other major disadvantages like multi-drug resistance, high dose requirements, aggravated toxicity, non-specificity of conventional drugs, and the emergence of drug-resistant parasites. Therefore, it is necessary to surpass these limitations and look for an alternative to curb the spread of this disease using an emerging technology platform. Nanomedicine is showing promise as an effective alternative tool for the management of malaria. The idea of this tool resonates well with David J. Triggle's outstanding suggestion "The chemist is as the astronaut, searching for biologically useful space in the chemical universe. This review presents a detailed discussion on various nanocarriers, their mode of action and future perspective in treating malaria. Nanotechnology-based drug delivery methods are highly specific, require a lower dose, offer more bioavailability with prolonged drug release and stay in the body longer. Recent nano drug encapsulation and delivery vehicles comprise nanocarriers like liposomes, and organic and inorganic nanoparticles, emerging as promising alternatives for malaria management.

Leaf hydroalcoholic extract and oleoresin from Copaifera multijuga control Toxoplasma gondii infection in human trophoblast cells and placental explants from third-trimester pregnancy

The conventional treatment of congenital toxoplasmosis is mainly based on the combination of sulfadiazine and pyrimethamine. However, therapy with these drugs is associated with severe side effects and resistance, requiring the study of new therapeutic strategies. There are currently many studies with natural products, including Copaifera oleoresin, showing actions against some pathogens, as Trypanosoma cruzi and Leishmania. In the present study, we investigated the effects of the leaf hydroalcoholic extract and oleoresin from Copaifera multijuga against Toxoplasma gondii in human villous (BeWo) and extravillous (HTR8/SVneo) trophoblast cells, as well as in human villous explants from third-trimester pregnancy. For this purpose, both cells and villous explants were infected or not with T. gondii, treated with hydroalcoholic extract or oleoresin from C. multijuga and analyzed for toxicity, parasite proliferation, cytokine and ROS production. In parallel, both cells were infected by tachyzoites pretreated with hydroalcoholic extract or oleoresin, and adhesion, invasion and replication of the parasite were observed. Our results showed that the extract and oleoresin did not trigger toxicity in small concentrations and were able to reduce the T. gondii intracellular proliferation in cells previously infected. Also, the hydroalcoholic extract and oleoresin demonstrated an irreversible antiparasitic action in BeWo and HTR8/SVneo cells. Next, adhesion, invasion and replication of T. gondii were dampened when BeWo or HTR8/SVneo cells were infected with pretreated tachyzoites. Finally, infected and treated BeWo cells upregulated IL-6 and downmodulated IL-8, while HTR8/SVneo cells did not change significantly these cytokines when infected and treated. Finally, both the extract and oleoresin reduced the T. gondii proliferation in human explants, and no significant changes were observed in relation to cytokine production. Thus, compounds from C. multijuga presented different antiparasitic activities that were dependent on the experimental model, being the direct action on tachyzoites a common mechanism operating in both cells and villi. Considering all these parameters, the hydroalcoholic extract and oleoresin from C. multijuga can be a target for the establishment of new therapeutic strategy for congenital toxoplasmosis.

Intestinal parasite infections among internal war refugees and inhabitants of the Ternopil region, Western Ukraine

BACKGROUND

The armed aggression of the Russian Federation against Ukraine resulted in the destruction of the country's infrastructure and a decline in the standard of living for many citizens (e.g. shortages of electricity and safe drinking water, limited access to healthcare, living in unsuitable cold basements). A lot of Ukrainians living in the eastern, southern and central parts of the country were forced to flee their homes. The aim of this study was to assess the prevalence of intestinal parasite infections among internal war refugees and residents of Ternopil, a city in Western Ukraine, in response to the worsening of the epidemiological situation in the country.

MATERIALS AND METHODS

Parasitological diagnostics was carried out in June 2023 and involved 127 adult Ukrainian citizens aged 19-80 years old, including 80 internal war refugees (most of the participants came from Donetsk, Luhansk, Dnipro, Kherson regions) and 47 residents of Ternopil region, Western Ukraine. Surveys and parasitological examination of stool samples by three different light microscopy testing methods (direct smear, decantation, flotation) were performed. The samples were then tested for the presence of Giardia intestinalis intestinal protozoa by molecular tests (reverse transcription polymerase chain reaction [RT-PCR]) and immunochromatographic rapid diagnostic tests (RDTs).

RESULTS

All RT-PCR and RDT tests to detect Giardia intestinalis were found to be negative. The examination of faecal samples taken from 127 patients showed no infections with nematodes, cestodes or trematodes. The examinations only revealed infections with potentially pathogenic Blastocystis spp.: 18/80 infections in the population of internal war refugees (22.5%) and 7/47 infections among residents of the Ternopil region (14.9%). Survey results demonstrated frequent use of antibiotics and antiparasitic drugs without physician advise or prescription: 43.9% of the study participants (n = 127) were taking antibiotics, and 25.2% were taking antiparasitic drugs during the period of 3 months prior to the study.

CONCLUSIONS

An absence of intestinal parasite pathogens was detected in the studied population. The authors may explain it by the fact, that many Ukrainian patients have unlimited access to antimicrobial drugs (drugs sold without a valid prescription and taken without consultation with a physician), which could have contributed to the low incidence of intestinal parasite infections.

Ivermectin role in COVID-19 treatment (IRICT): single-center, adaptive, randomized, double-blind, placebo-controlled, clinical trial

BACKGROUND

To investigate the efficacy and safety of ivermectin compared to hydroxychloroquine and placebo in hospitalized moderate to severe COVID-19 patients.

RESEARCH DESIGN AND METHODS

The study was an adaptive, randomized, double-blinded, controlled, single-center trial. The study was a series of 3-arm comparisons between two different investigational therapeutic agents (ivermectin and hydroxychloroquine) and a placebo. There was interim monitoring to allow early stopping for futility, efficacy, or safety.

RESULTS

Ivermectin decreased survival time from 29 to 18.3 days (HR, 9.8, 95%CI, 3.7-26.2), while it did not shorten the recovery time (HR, 1.02, 95%CI, 0.69-1.5). Subgroup analysis showed an association between ivermectin-related mortality and baseline oxygen saturation level. Moreover, stratified groups showed higher risk among patients on high flow O2. Hydroxychloroquine delayed recovery from 10.1 to 12.5 days (HR, 0.62, 95%CI, 0.4-0.95) and non-significantly decreased survival time from 29 to 26.8 days (HR, 1.47, 95%CI, 0.73-2.9). However, 3 months mortality rates were increased with hydroxychloroquine (RR, 2.05, 95%CI, 1.33-3.16). Neither ivermectin nor hydroxychloroquine increased adverse events and demonstrated safety profile compared to placebo.

CONCLUSIONS

The study recommends against using either ivermectin or hydroxychloroquine for treatment of COVID-19 in hospitalized patients with any degree of severity. Clinical trial registration: www.clinicaltrials.gov identifier is: NCT04746365.

The emerging role of Deubiquitinases (DUBs) in parasites: A foresight review

Before the discovery of the proteasome complex, the lysosomes with acidic proteases and caspases in apoptotic pathways were thought to be the only pathways for the degradation of damaged, unfolded, and aged proteins. However, the discovery of 26S and 20S proteasome complexes in eukaryotes and microbes, respectively, established that the degradation of most proteins is a highly regulated ATP-dependent pathway that is significantly conserved across each domain of life. The proteasome is part of the ubiquitin-proteasome system (UPS), where the covalent tagging of a small molecule called ubiquitin (Ub) on the proteins marks its proteasomal degradation. The type and chain length of ubiquitination further determine whether a protein is designated for further roles in multi-cellular processes like DNA repair, trafficking, signal transduction, etc., or whether it will be degraded by the proteasome to recycle the peptides and amino acids. Deubiquitination, on the contrary, is the removal of ubiquitin from its substrate molecule or the conversion of polyubiquitin chains into monoubiquitin as a precursor to ubiquitin. Therefore, deubiquitylating enzymes (DUBs) can maintain the dynamic state of cellular ubiquitination by releasing conjugated ubiquitin from proteins and controlling many cellular pathways that are essential for their survival. Many DUBs are well characterized in the human system with potential drug targets in different cancers. Although, proteasome complex and UPS of parasites, like plasmodium and leishmania, were recently coined as multi-stage drug targets the role of DUBs is completely unexplored even though structural domains and functions of many of these parasite DUBs are conserved having high similarity even with its eukaryotic counterpart. This review summarizes the identification & characterization of different parasite DUBs based on in silico and a few functional studies among different phylogenetic classes of parasites including Metazoan (Schistosoma, Trichinella), Apicomplexan protozoans (Plasmodium, Toxoplasma, Eimeria, Cryptosporidium), Kinetoplastidie (Leishmania, Trypanosoma) and Microsporidia (Nosema). The identification of different homologs of parasite DUBs with structurally similar domains with eukaryotes, and the role of these DUBs alone or in combination with the 20S proteosome complex in regulating the parasite survival/death is further elaborated. We propose that small molecules/inhibitors of human DUBs can be potential antiparasitic agents due to their significant structural conservation.