Quantifying the fitness effects of resistance alleles with and without anthelmintic selection pressure using Caenorhabditis elegans.

Albendazole (a benzimidazole) and ivermectin (a macrocyclic lactone) are the two most commonly co-administered anthelmintic drugs in mass-drug administration programs worldwide. Despite emerging resistance, we do not fully understand the mechanisms of resistance to these drugs nor the consequences of delivering them in combination. Albendazole resistance has primarily been attributed to variation in the drug target, a beta-tubulin gene. Ivermectin targets glutamate-gated chloride channels (GluCls), but it is unknown whether GluCl genes are involved in ivermectin resistance in nature. Using Caenorhabditis elegans, we defined the fitness costs associated with loss of the drug target genes singly or in combinations of the genes that encode GluCl subunits. We quantified the loss-of-function effects on three traits: (i) multi-generational competitive fitness, (ii) fecundity, and (iii) development. In competitive fitness and development assays, we found that a deletion of the beta-tubulin gene ben-1 conferred albendazole resistance, but ivermectin resistance required the loss of two GluCl genes (avr-14 and avr-15). The fecundity assays revealed that loss of ben-1 did not provide any fitness benefit in albendazole conditions and that no GluCl deletion mutants were resistant to ivermectin. Next, we searched for evidence of multi-drug resistance across the three traits. Loss of ben-1 did not confer resistance to ivermectin, nor did loss of any single GluCl subunit or combination confer resistance to albendazole. Finally, we assessed the development of 124 C. elegans wild strains across six benzimidazoles and seven macrocyclic lactones to identify evidence of multi-drug resistance between the two drug classes and found a strong phenotypic correlation within a drug class but not across drug classes. Because each gene affects various aspects of nematode physiology, these results suggest that it is necessary to assess multiple fitness traits to evaluate how each gene contributes to anthelmintic resistance.

Re-examining the evidence that ivermectin induces a melanoma-like state in Xenopus embryos.

Modeling metastasis in animal systems has been an important focus for developing cancer therapeutics. Xenopus laevis is a well-established model, known for its use in identifying genetic mechanisms underlying diseases and disorders in humans. Prior literature has suggested that the drug, ivermectin, can be used in Xenopus to induce melanocytes to convert into a metastatic melanoma-like state, and thus could be ideal for testing possible melanoma therapies in vivo. However, there are notable inconsistencies between ivermectin studies in Xenopus and the application of ivermectin in mammalian systems, that are relevant to cancer and melanoma research. In this review, we examine the ivermectin-induced phenotypes in Xenopus, and we explore the current uses of ivermectin in human research. We conclude that while ivermectin may be a useful drug for many biomedical purposes, it is not ideal to induce a metastatic melanocyte phenotype in Xenopus for testing the effects of potential melanoma therapeutics.

A new family of glutamate-gated chloride channels in parasitic sea louse Caligus rogercresseyi: A subunit refractory to activation by ivermectin is dominant in heteromeric assemblies.

Sea louse ectoparasitosis is a major threat to fish aquaculture. Avermectins such as ivermectin and emamectin have been effectively used against sea louse infestation, but the emergence of resistance has limited their use. A better understanding of the molecular targets of avermectins is essential to the development of novel treatment strategies or new, more effective drugs. Avermectins are known to act by inhibiting neurotransmission through allosteric activation of glutamate-gated chloride channels (GluCls). We have investigated the GluCl subunit present in Caligus rogercresseyi, a sea louse affecting aquaculture in the Southern hemisphere. We identify four new subunits, CrGluCl-B to CrGluCl-E, and characterise them functionally. CrGluCl-A (previously reported as CrGluClα), CrGluCl-B and CrGluCl-C all function as glutamate channel receptors with different sensitivities to the agonist, but in contrast to subunit -A and -C, CrGluCl-B is not activated by ivermectin but is rather antagonised by the drug. CrGluCl-D channel appears active in the absence of any stimulation by glutamate or ivermectin and CrGluCl-E does not exhibit any activity. Notably, the expression of CrGluCl-B with either -A or -C subunits gives rise to receptors unresponsive to ivermectin and showing altered response to glutamate, suggesting that coexpression has led to the preferential formation of heteromers to which the presence of CrGluCl-B confers the property of ivermectin-activation refractoriness. Furthermore, there was evidence for heteromer formation with novel properties only when coexpressing pairs E/C and D/B CrGluCl subtypes. Site-directed mutagenesis shows that three transmembrane domain residues contribute to the lack of activation by ivermectin, most crucially Gln 15' in M2, with mutation Q15'T (the residue present in ivermectin-activated subunits A and C) conferring ivermectin activation to CrGluCl-B. The differential response to avermectin of these Caligus rogercresseyi GluClsubunits, which are highly conserved in the Northern hemisphere sea louse Lepeophtheirus salmonis, could have an influence on the response of these parasites to treatment with macrocyclic lactones. They could serve as molecular markers to assess susceptibility to existing treatments and might be useful molecular targets in the search for novel antiparasitic drugs.

Nodulisporic acid produces direct activation and positive allosteric modulation of AVR-14B, a glutamate-gated chloride channel from adult Brugia malayi.

Glutamate-gated chloride channels (GluCls) are unique to invertebrates and are targeted by macrocyclic lactones. In this study, we cloned an AVR-14B GluCl subunit from adult Brugia malayi, a causative agent of lymphatic filariasis in humans. To elucidate this channel's pharmacological properties, we used Xenopus laevis oocytes for expression and performed two-electrode voltage-clamp electrophysiology. The receptor was gated by the natural ligand L-glutamate (effective concentration, 50% [EC50] = 0.4 mM) and ivermectin (IVM; EC50 = 1.8 nM). We also characterized the effects of nodulisporic acid (NA) on Bma-AVR-14B and NA-produced dual effects on the receptor as an agonist and a type II positive allosteric modulator. Here we report characterization of the complex activity of NA on a nematode GluCl. Bma-AVR-14B demonstrated some unique pharmacological characteristics. IVM did not produce potentiation of L-glutamate-mediated responses but instead, reduced the channel's sensitivity for the ligand. Further electrophysiological exploration showed that IVM (at a moderate concentration of 0.1 nM) functioned as an inhibitor of both agonist and positive allosteric modulatory effects of NA. This suggests that IVM and NA share a complex interaction. The pharmacological properties of Bma-AVR-14B indicate that the channel is an important target of IVM and NA. In addition, the unique electrophysiological characteristics of Bma-AVR-14B could explain the observed variation in drug sensitivities of various nematode parasites. We have also shown the inhibitory effects of IVM and NA on adult worm motility using Worminator. RNA interference (RNAi) knockdown suggests that AVR-14 plays a role in influencing locomotion in B. malayi.

Human strongyloidiasis: complexities and pathways forward.

Strongyloidiasis is a World Health Organization neglected tropical disease usually caused by Strongyloides stercoralis, a parasitic worm with a complex life cycle. Globally, 300-600 million people are infected through contact with fecally contaminated soil. An autoinfective component of the life cycle can lead to chronic infection that may be asymptomatic or cause long-term symptoms, including malnourishment in children. Low larval output can limit the sensitivity of detection in stool, with serology being effective but less sensitive in immunocompromise. Host immunosuppression can trigger catastrophic, fatal hyperinfection/dissemination, where large numbers of larvae pierce the bowel wall and disseminate throughout the organs. Stable disease is effectively treated by single-dose ivermectin, with disease in immunocompromised patients treated with multiple doses. Strategies for management include raising awareness, clarifying zoonotic potential, the development and use of effective diagnostic tests for epidemiological studies and individual diagnosis, and the implementation of treatment programs with research into therapeutic alternatives and medication safety.

Niclosamide, but not ivermectin, inhibits anoctamin 1 and 6 and attenuates inflammation of the respiratory tract.

Inflammatory airway diseases like cystic fibrosis, asthma and COVID-19 are characterized by high levels of pulmonary cytokines. Two well-established antiparasitic drugs, niclosamide and ivermectin, are intensively discussed for the treatment of viral inflammatory airway infections. Here, we examined these repurposed drugs with respect to their anti-inflammatory effects in airways in vivo and in vitro. Niclosamide reduced mucus content, eosinophilic infiltration and cell death in asthmatic mouse lungs in vivo and inhibited release of interleukins in the two differentiated airway epithelial cell lines CFBE and BCi-NS1.1 in vitro. Cytokine release was also inhibited by the knockdown of the Ca2+-activated Cl- channel anoctamin 1 (ANO1, TMEM16A) and the phospholipid scramblase anoctamin 6 (ANO6, TMEM16F), which have previously been shown to affect intracellular Ca2+ levels near the plasma membrane and to facilitate exocytosis. At concentrations around 200 nM, niclosamide inhibited inflammation, lowered intracellular Ca2+, acidified cytosolic pH and blocked activation of ANO1 and ANO6. It is suggested that niclosamide brings about its anti-inflammatory effects at least in part by inhibiting ANO1 and ANO6, and by lowering intracellular Ca2+ levels. In contrast to niclosamide, 1 µM ivermectin did not exert any of the effects described for niclosamide. The present data suggest niclosamide as an effective anti-inflammatory treatment in CF, asthma, and COVID-19, in addition to its previously reported antiviral effects. It has an advantageous concentration-response relationship and is known to be well tolerated.

Ivermectin as a potential therapeutic strategy for glioma.

Ivermectin (IVM), a semi-synthetic macrolide parasiticide, has demonstrated considerable effectiveness in combating internal and external parasites, particularly nematodes and arthropods. Its remarkable ability to control parasites has earned it significant recognition, culminating in Satoshi Omura and William C. Campbell's receipt of the 2015 Nobel Prize in Physiology or Medicine for their contributions to the development of IVM. In recent years, investigations have revealed that IVM possesses antitumor properties. It can suppress the growth of various cancer cells, including glioma, through a multitude of mechanisms such as selective targeting of tumor-specific proteins, inducing programmed cell death, and modulation of tumor-related signaling pathways. Hence, IVM holds tremendous potential as a novel anticancer drug. This review seeks to provide an overview of the underlying mechanisms that enable IVM's capacity to suppress glioma. Furthermore, it aims to elucidate the challenges and prospects associated with utilizing IVM as a new anticancer agent.

Transcriptomic analyses implicate neuronal plasticity and chloride homeostasis in ivermectin resistance and response to treatment in a parasitic nematode.

The antiparasitic drug ivermectin plays an essential role in human and animal health globally. However, ivermectin resistance is widespread in veterinary helminths and there are growing concerns of sub-optimal responses to treatment in related helminths of humans. Despite decades of research, the genetic mechanisms underlying ivermectin resistance are poorly understood in parasitic helminths. This reflects significant uncertainty regarding the mode of action of ivermectin in parasitic helminths, and the genetic complexity of these organisms; parasitic helminths have large, rapidly evolving genomes and differences in evolutionary history and genetic background can confound comparisons between resistant and susceptible populations. We undertook a controlled genetic cross of a multi-drug resistant and a susceptible reference isolate of Haemonchus contortus, an economically important gastrointestinal nematode of sheep, and ivermectin-selected the F2 population for comparison with an untreated F2 control. RNA-seq analyses of male and female adults of all populations identified high transcriptomic differentiation between parental isolates, which was significantly reduced in the F2, allowing differences associated specifically with ivermectin resistance to be identified. In all resistant populations, there was constitutive upregulation of a single gene, HCON_00155390:cky-1, a putative pharyngeal-expressed transcription factor, in a narrow locus on chromosome V previously shown to be under ivermectin selection. In addition, we detected sex-specific differences in gene expression between resistant and susceptible populations, including constitutive upregulation of a P-glycoprotein, HCON_00162780:pgp-11, in resistant males only. After ivermectin selection, we identified differential expression of genes with roles in neuronal function and chloride homeostasis, which is consistent with an adaptive response to ivermectin-induced hyperpolarisation of neuromuscular cells. Overall, we show the utility of a genetic cross to identify differences in gene expression that are specific to ivermectin selection and provide a framework to better understand ivermectin resistance and response to treatment in parasitic helminths.

Identification of inositol monophosphatase as a broad-spectrum antiviral target of ivermectin.

Ivermectin has broad-spectrum antiviral activities. Despite the failure in clinical application of COVID-19, it can serve as a lead compound for the development of more effective broad-spectrum antivirals, for which a better understanding of its antiviral mechanisms is essential. We thus searched for potential novel targets of ivermectin in host cells by label-free thermal proteomic profiling using Huh-7 cells. Inositol monophosphatase (IMPase) was found among the proteins with shifted thermal stability by ivermectin. Ivermectin could inhibit IMPase activity and reduce cellular myo-inositol and phosphatidylinositol-4-phosphate levels. On the other hand, inositol could impair the antiviral activity of ivermectin and lithium, an IMPase inhibitor with known antiviral activity. As phosphatidylinositol phosphate is crucial for the replication of many RNA viruses, inhibition of cellular myo-inositol biosynthesis may be an important antiviral mechanism of ivermectin. Hence, inhibition of IMPase could serve as a potential target for broad-spectrum antiviral development.

Ivermectin antiviral activity against Varicellovirus bovinealpha 1: assessment of intracellular drug accumulation in virus-infected cells.

Varicellovirus bovinealpha 1 (formerly bovine alphaherpesvirus type 1, BoAHV-1) is associated with several syndromes in cattle, including respiratory disease and is one of the main agents involved in the bovine respiratory disease complex (BRDC). Its infectious cycle is characterized by latent infections with sporadic virus reactivation and transmission. Although the acute disease can be prevented by the use of vaccines, specific therapeutic measures are not available. Ivermectin (IVM) is a semi-synthetic avermectin with a broad-spectrum antiparasitic activity, which has previously shown to have potential as an antiviral drug. In this study, IVM antiviral activity against BoAHV-1 was characterized in two cell lines (MDBK [Madin Darby bovine kidney] and BT [bovine turbinate]), including the measurement of intracellular drug accumulation within virus-infected cells. IVM antiviral activity was assessed at three different drug concentrations (1.25, 2.5 and 5 µM) after incubation for 24, 48 and 72 h. Slight cytotoxicity was only observed with 5 µM IVM. Even the lowest IVM dose was able to induce a significant reduction in virus titers in both cell lines. These findings indicate that the antiviral effects of IVM were evident in our experimental model within the range of concentrations achievable through therapeutic in vivo administration. Consequently, additional in vivo trials are necessary to validate the potential utility of these results in effectively managing BoAHV-1 in infected cattle.

Ecofriendly Controlled-Release Insecticide Carrier: pH-/Temperature-Responsive Rosin-Derived Hydrogels for Avermectin Delivery against Mythimna separata (Walker).

The exploration of environmentally friendly, less toxic, sustained-release insecticide is increasing with the growing demand for food to meet the requirements of the expanding population. As a sustained-release carrier, the unique, environmentally friendly intelligent responsive hydrogel system is an important factor in improving the efficiency of insecticide utilization and accurate release. In this study, we developed a facile approach for incorporating the natural compound rosin (dehydroabietic acid, DA) and zinc ions (Zn2+) into a poly(N-isopropylacrylamide) (PNIPAM) hydrogel network to construct a controlled-release hydrogel carrier (DA-PNIPAM-Zn2+). Then, the model insecticide avermectin (AVM) was encapsulated in the carrier at a drug loading rate of 36.32% to form AVM@DA-PNIPAM-Zn2+. Surprisingly, the smart controlled carrier exhibited environmental responsiveness, strongly enhanced mechanical properties, self-healing ability, hydrophobicity, and photostability to ensure a balance between environmental friendliness and the precision of the drug release. The release experiments showed that the carboxyl and amide groups in the polymer chains alter the intermolecular forces within the hydrogel meshes and ingredient diffusion by changing temperatures (25 and 40 °C) and pH values (5.8, 7.4, and 8.5), leading to different release behaviors. The insecticidal activity of the AVM@DA-PNIPAM-Zn2+ against oriental armyworms was good, with an effective minimum toxicity toward aquatic animals. Therefore, AVM@DA-PNIPAM-Zn2+ is an effective drug delivery system against oriental armyworms. We anticipate that this ecofriendly, sustainable, smart-response carrier may broaden the utilization rosin and its possible applications in the agricultural sector.

Real-time tilting and twisting motions of ligand-bound states of α7 nicotinic acetylcholine receptor.

The α7 nicotinic acetylcholine receptor is a member of the nicotinic acetylcholine receptor family and is composed of five α7 subunits arranged symmetrically around a central pore. It is localized in the central nervous system and immune cells and could be a target for treating Alzheimer's disease and schizophrenia. Acetylcholine is a ligand that opens the channel, although prolonged application rapidly decreases the response. Ivermectin was reported as one of the positive allosteric modulators, since the binding of Ivermectin to the channel enhances acetylcholine-evoked α7 currents. One research has suggested that tilting motions of the nicotinic acetylcholine receptor are responsible for channel opening and activation. To verify this hypothesis applies to α7 nicotinic acetylcholine receptor, we utilized a diffracted X-ray tracking method to monitor the stable twisting and tilting motion of nAChR α7 without a ligand, with acetylcholine, with Ivermectin, and with both of them. The results show that the α7 nicotinic acetylcholine receptor twists counterclockwise with the channel transiently opening, transitioning to a desensitized state in the presence of acetylcholine and clockwise without the channel opening in the presence of Ivermectin. We propose that the conformational transition of ACh-bound nAChR α7 may be due to the collective twisting of the five α7 subunits, resulting in the compression and movement, either downward or upward, of one or more subunits, thus manifesting tilting motions. These tilting motions possibly represent the transition from the resting state to channel opening and potentially to the desensitized state.

In-vitro susceptibility and ex-vivo evaluation of macrocyclic lactone endectocides sub-lethal concentrations against Plasmodium vivax oocyst development in Anopheles arabiensis.

BACKGROUND: Asymptomatic malaria transmission has become a public health concern across malaria-endemic Africa including Ethiopia. Specifically, Plasmodium vivax is more efficient at transmitting earlier in the infection and at lower densities than Plasmodium falciparum. Consequently, a greater proportion of individuals infected with P. vivax can transmit without detectable gametocytaemia. Mass treatment of livestock with macrocyclic lactones (MLs), e.g., ivermectin and doramectin, was suggested as a complementary malaria vector tool because of their insecticidal effects. However, the effects of MLs on P. vivax in Anopheles arabiensis has not yet been fully explored. Hence, comparative in-vitro susceptibility and ex-vivo studies were conducted to evaluate the effects of ivermectin, doramectin and moxidectin sub-lethal concentrations on P. vivax oocyst development in An. arabiensis. METHODS: The 7-day sub-lethal concentrations of 25% (LC25) and 5% (LC5) were determined from in-vitro susceptibility tests on female An. arabiensis in Hemotek® membrane feeding assay. Next, an ex-vivo study was conducted using P. vivax gametocytes infected patient's blood spiked with the LC25 and LC5 of the MLs. At 7-days post-feeding, each mosquito was dissected under a dissection stereo microscope, stained with 0.5% (w/v) mercurochrome solution, and examined for the presence of P. vivax oocysts. Statistical analysis was based on a generalized mixed model with binomially distributed error terms. RESULTS: A 7-day lethal concentration of 25% (LC25, in ng/mL) of 7.1 (95% CI: [6.3;8.0]), 20.0 (95%CI:[17.8;22.5]) and 794.3 (95%CI:[716.4;1516.3]) were obtained for ivermectin, doramectin and moxidectin, respectively. Similarly, a lethal concentration of 5% (LC5, in ng/mL) of 0.6 (95% CI: [0.5;0.7]), 1.8 (95% CI:[1.6;2.0]) and 53.7 (95% CI:[ 48.4;102.5]) were obtained respectively for ivermectin, doramectin and moxidectin. The oocyst prevalence in treatment and control groups did not differ significantly (p > 0.05) from each other. Therefore, no direct effect of ML endectocides on P. vivax infection in An. arabiensis mosquitoes was observed at the sub-lethal concentration (LC25 and LC5). CONCLUSIONS: The effects of ivermectin and doramectin on malaria parasite is more likely via indirect effects, particularly by reducing the vectors lifespan and causing mortality before completing the parasite's sporogony cycle or reducing their vector capacity as it affects the locomotor activity of the mosquito.

Ferulic acid alleviates avermectin induced renal injury in carp by inhibiting inflammation, oxidative stress and apoptosis.

Avamectin (AVM), a macrolide antibiotic, is widely used in fisheries, agriculture, and animal husbandry, however, its irrational use poses a great danger to aquatic organisms. Ferulic acid (FA) is a natural chemical found in the cell walls of plants. It absorbs free radicals from the surrounding environment and acts as an antioxidant. However, the protective effect of FA against kidney injury caused by AVM has not been demonstrated. In this study, 60 carp were divided into the control group, AVM group (2.404 µg/L), FA+AVM group and FA group (400 mg/kg). Pathological examination, quantitative real-time PCR (qPCR), reactive oxygen species (ROS) and western blot were used to evaluate the preventive effect of FA on renal tissue injury after AVM exposure. Histological findings indicated that FA significantly reduced the swelling and infiltration of inflammatory cells in the kidney tissues of carp triggered by AVM. Dihydroethidium (DHE) fluorescent probe assay showed that FA inhibited the accumulation of kidney ROS. Biochemical results showed that FA significantly increased glutathione (GSH) content, total antioxidant capacity (T-AOC) and catalase (CAT) activity, and decreased intracellular malondialdehyde (MDA) content. In addition, western blot results revealed that the protein expression levels of Nrf2 and p-NF-κBp65 in the carp kidney were inhibited by AVM, but reversed by the FA. The qPCR results exhibited that FA significantly increased the mRNA levels of tgf-ß1 and il-10, while significantly down-regulated the gene expression levels of tnf-α, il-6 and il-1ß. These data suggest that FA can reduce oxidative stress and renal tissue inflammation induced by AVM. At the same time, FA inhibited the apoptosis of renal cells induced by AVM by decreasing the transcription level and protein expression level of Bax, and increasing the transcription level and protein expression level of Bcl2, PI3K and AKT. This study provides preliminary evidence for the theory that FA reduces the level of oxidative stress, inflammation response and kidney tissue damage caused by apoptosis in carp, providing a theoretical basis for the prevention and treatment of the AVM.

Combined in silico and in vitro approaches to identify P-glycoprotein-inhibiting pesticides.

The P-glycoprotein (P-gp) efflux pump plays a major role in xenobiotic detoxification. The inhibition of its activity by environmental contaminants remains however rather little characterised. The present study was designed to develop a combination of different approaches to identify P-gp inhibitors among a large number of pesticides using in silico and in vitro models. First, the prediction performance of four web tools was evaluated alone or in combination using a set of recently marketed drugs. The best combination of web tools-AdmetSAR2.0/PgpRules/pkCSM-was next used to predict P-gp activity inhibition by 762 pesticides. Among the 187 pesticides predicted to be P-gp inhibitors, 11 were tested in vitro for their ability to inhibit the efflux of reference substrates (rhodamine 123 and Hoechst 33342) in P-gp overexpressing MCF7R cells and to inhibit the efflux of the reference substrate rhodamine 123 in the Caco-2 cell monolayer. In MCF7R cell assays, ivermectin B1a, emamectin B1 benzoate, spinosad, dimethomorph and tralkoxydim inhibited P-gp activity; ivermectin B1a, emamectin B1 benzoate and spinosad were determined to be stronger inhibitors (half-maximal inhibitory concentration [IC50 ] of 3 ± 1, 5 ± 1 and 7 ± 1 µM, respectively) than dimethomorph and tralkoxydim (IC50 of 102 ± 7 and 88 ± 7 µM, respectively). Ivermectin B1a, emamectin B1 benzoate, spinosad and dimethomorph also inhibited P-gp activity in Caco-2 cell monolayer assays, with dimethomorph being a weaker P-gp inhibitor. These combined approaches could be used to identify P-gp inhibitors among food contaminants, but need to be optimised and adapted for high-throughput screening.

First insights on the susceptibility of native coccidicidal fungi Mucor circinelloides and Mucor lusitanicus to different avian antiparasitic drugs.

BACKGROUND: The combined application of predatory fungi and antiparasitic drugs is a sustainable approach for the integrated control of animal gastrointestinal (GI) parasites. However, literature addressing the possible interference of antiparasitic drugs on the performance of these fungi is still scarce. This research aimed to assess the in vitro susceptibility of six native coccidicidal fungi isolates of the species Mucor circinelloides and one Mucor lusitanicus isolate to several antiparasitic drugs commonly used to treat GI parasites' infections in birds, namely anthelminthics such as Albendazole, Fenbendazole, Levamisole and Ivermectin, and anticoccidials such as Lasalocid, Amprolium and Toltrazuril (drug concentrations of 0.0078-4 µg/mL), using 96-well microplates filled with RPMI 1640 medium, and also on Sabouraud Agar (SA). RESULTS: This research revealed that the exposition of all Mucor isolates to the tested anthelminthic and anticoccidial drug concentrations did not inhibit their growth. Fungal growth was recorded in RPMI medium, after 48 h of drug exposure, as well as on SA medium after exposure to the maximum drug concentration. CONCLUSIONS: Preliminary findings from this research suggest the potential compatibility of these Mucor isolates with antiparasitic drugs for the integrated control of avian intestinal parasites. However, further in vitro and in vivo studies are needed to confirm this hypothesis.

Drug repurposing-based nanoplatform via modulating autophagy to enhance chemo-phototherapy against colorectal cancer.

Multi-modal combination therapy is regarded as a promising approach to cancer treatment. Combining chemotherapy and phototherapy is an essential multi-modal combination therapy endeavor. Ivermectin (IVM) is a potent antiparasitic agent identified as having potential antitumor properties. However, the fact that it induces protective autophagy while killing tumor cells poses a challenge to its further application. IR780 iodide (IR780) is a near-infrared (NIR) dye with outstanding photothermal therapy (PTT) and photodynamic therapy (PDT) effects. However, the hydrophobicity, instability, and low tumor uptake of IR780 limit its clinical applications. Here, we have structurally modified IR780 with hydroxychloroquine, an autophagy inhibitor, to synthesize a novel compound H780. H780 and IVM can form H780-IVM nanoparticles (H-I NPs) via self-assembly. Using hyaluronic acid (HA) to modify the H-I NPs, a novel nano-delivery system HA/H780-IVM nanoparticles (HA/H-I NPs) was synthesized for chemotherapy-phototherapy of colorectal cancer (CRC). Under NIR laser irradiation, HA/H-I NPs effectively overcame the limitations of IR780 and IVM and exhibited potent cytotoxicity. In vitro and in vivo experiment results showed that HA/H-I NPs exhibited excellent anti-CRC effects. Therefore, our study provides a novel strategy for CRC treatment that could enhance chemo-phototherapy by modulating autophagy.

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.

Moxidectin versus Ivermectin in the prevention and treatment of acute and chronic experimental trichinellosis.

The limited activity of the traditional medications against T. spiralis encysted larvae handicaps complete cure of trichinellosis till now due to decreased permeability and absorption through tissues. MOX is listed worldwide for prevention and treatment of several internal and external nematodes. Consequently, the aim of this work was to investigate the effect of moxidectin versus ivermectin on experimental acute and chronic trichinellosis and to illuminate the potential mechanisms of their effects. 105 Mice were divided into four groups; Group I: Uninfected healthy control; Group II: Infected untreated control; Group III: Infected and treated with IVM and Group IV: Infected and treated with MOX. The groups (II, III and IV) were later subdivided equally into three subgroups (a, b, and c) according to the stage of treatment. Parasitological counting of adults and larvae besides immune-histopathological examination of intestines and muscles were done. Results exhibited that both IVM and MOX succeeded in reducing adults and larvae counts with higher potential of MOX in both intestinal and muscle phase. The preeminence of MOX was indicated by decreased inflammation, a significant reduction in the microvascular density (CD31 immunostaining) as well as a reduction in the percentage of fibroblast activation protein (FAP) immunostaining in muscle tissues. Accordingly, the current work recommends moxidectin as an innovative treatment for trichinellosis.

The response of Anisakis simplex (s. s.) to anthelmintics - Specific changes in xenobiotic metabolic processes.

Anisakiasis is a parasitic disease transmitted through the consumption of raw or undercooked fish and cephalopods that are infected with larvae of Anisakis simplex (sensu stricto) or Anisakis pegreffii. The purpose of this study was to investigate how A. simplex (s. s.) responds to the influence of anthelmintics such as ivermectin (IVM) and pyrantel (PYR). In vitro experiments were conducted using larvae at two developmental stages of A. simplex (s. s.) (L3 and L4) obtained from Baltic herring (Clupea harengus membras). Larvae were cultured with different concentrations of IVM or PYR (1.56, 3.125, and 6.25 µg/mL) for various durations (3, 6, 9, and 12 h) under anaerobic conditions (37 °C, 5% CO2). The gene expression of actin, ABC transporter, antioxidant enzymes, γ-aminobutyric acid receptors, and nicotinic acetylcholine receptors, as well as the oxidative status were analyzed. The results showed that A. simplex (s. s.) L3 stage had lower mobility when cultured with PYR compared to IVM. The analysis of relative gene expression revealed significant differences in the mRNA level of ABC transporters after treatment with IVM and PYR, compared to the control group. Similar patterns were observed in the gene expression of antioxidant enzymes in response to both drugs. Furthermore, the total antioxidant capacity (TAC) and glutathione S-transferase (GST) activity were higher in the treatment groups than in the control group. These findings suggest a relationship between the expression of the studied genes, including those related to oxidative metabolism, and the effectiveness of the tested drugs.