Fenbendazole Treatment Research Articles

Northern bobwhite (Colinus virginianus) population response to anthelminthic treatment in the Rolling Plains ecoregion of Texas, 2014–2016

Northern bobwhite quail (Colinus virginianus) are an economically significant gamebird that has experienced continued general decline in the Rolling Plains ecoregion of Texas. Habitat loss and changing environmental conditions have been cited as major contributors to this decline, with factors such as parasites being considered inconsequential. To better assess the impacts of parasite infections on bobwhite populations in the Rolling Plains, bobwhite abundance was monitored in response to anthelminthic treatment. With the prevalence of Oxyspirura petrowi and Aulonocephalus pennula infections in quail from Mitchell County, Texas confirmed by previous studies, the anthelminthic agent Fenbendazole was introduced as a means of parasite control in 2014–2015. Bobwhite abundance was determined through a series of call counts which provided an index of bobwhite populations and were conducted throughout the course of the study. In 2016, call counts revealed a significant increase of bobwhite in the area subject to Fenbendazole treatment, while untreated areas showed no changes in abundance. Fall populations of bobwhite in the treated zone approached 300% of those in untreated areas, these findings suggest that parasites may have a more significant impact on quail populations in the Rolling Plains than previously suspected. With the importance of bobwhite as a game bird in the Rolling Plains, the potential impacts of parasites must be taken into consideration as a factor contributing to bobwhite declines. Further research into the long-term effects these parasites have on quail populations in the ecoregion may aid landowners in developing affordable and effective conservation strategies.

Efficacy of a New Fenbendazole Treatment Protocol against Capillaria spp. in Northern White-Breasted Hedgehog (Erinaceus roumanicus)

Hedgehogs, Erinaceus spp., are commonly admitted to rescue centres in European countries. However, there are still few studies on parasitological fauna and treatment possibilities, including for E. roumanicus. This study aimed to evaluate parasitism in 34 hedgehogs directly after their admission to the Budapest Zoo and Botanical Garden Wildlife Rescue Centre, as well as the efficacy of fenbendazole treatment. The Mini-Flotac method was used to quantitatively evaluate and assess the efficacy of treatment with fenbendazole (100 mg/kg PO. BID for 7 days) in five selected individuals. Faecal samples were analysed at D0 and D14 after the beginning of the treatment. Globally, the prevalence of positive animals was 76%. Capillaria spp. were the most prevalent (68%), while coccidia showed a prevalence of 32%. Considering the range of action of this benzimidazole, the treatment provided an efficacy of 100%, eliminating all forms of Capillaria spp. Considering the high number of hedgehogs admitted to rescue centres and the potential effects of parasitism in morbidity and mortality during recovery, it is essential to improve our knowledge with regard to the parasitological fauna of these species and to attain effective treatment protocols.

Proteomics reveals that the antifungal activity of fenbendazole against Cryptococcus neoformans requires protein kinases

Cryptococcus neoformans is responsible for over 100 000 deaths annually, and the treatment of this fungal disease is expensive and not consistently effective. Unveiling new therapeutic avenues is crucial. Previous studies have suggested that the anthelmintic drug fenbendazole is an affordable and nontoxic candidate to combat cryptococcosis. However, its mechanism of anticryptococcal activity has been only superficially investigated. In this study, we examined the global cellular response of C. neoformans to fenbendazole using a proteomic approach (data are available via ProteomeXchange with identifier PXD047041). Fenbendazole treatment mostly impacted the abundance of proteins related to metabolic pathways, RNA processing, and intracellular traffic. Protein kinases, in particular, were significantly affected by fenbendazole treatment. Experimental validation of the proteomics data using a collection of C. neoformans mutants led to the identification of critical roles of five protein kinases in fenbendazole's antifungal activity. In fact, mutants lacking the expression of genes encoding Chk1, Tco2, Tco3, Bub1, and Sch9 kinases demonstrated greater resistance to fenbendazole compared to wild-type cells. In combination with the standard antifungal drug amphotericin B, fenbendazole reduced the cryptococcal burden in mice. These findings not only contribute to the elucidation of fenbendazole's mode of action but also support its use in combination therapy with amphotericin B. In conclusion, our data suggest that fenbendazole holds promise for further development as an anticryptococcal agent.

A fecal egg count reduction test in grazing beef steers using topical pioneer and generic eprinomectin and fenbendazole oral suspension.

Many generic anthelmintics are commercially available; however, little information exists regarding product effectiveness compared to pioneer brands. The objective of this study was to compare the effectiveness of a generic eprinomectin to the pioneer eprinomectin, as well as to fenbendazole and fenbendazole in combination with the pioneer eprinomectin in grazing beef steers via a fecal egg count reduction test. Forty naturally infected steers were allocated into five treatment groups based on ranked fecal egg counts: 1. pioneer eprinomectin (Eprinex®, topical), 2. generic eprinomectin (Eprizero®, topical), 3. fenbendazole (Safeguard® 0.5% oral suspension), 4. combination of pioneer eprinomectin topical and fenbendazole oral suspension, 5. negative control. Fecal samples were collected on days -14, 0, 14, and 29. Data were analyzed using the MIXED procedure of SAS 9.4. Neither the pioneer nor the generic eprinomectin groups reached a 90% fecal egg count reduction (FECR) throughout the study with reductions of 50% and 11% for pioneer eprinomectin and 79% and-5% for generic eprinomectin at days 14 and 29 post-treatment, respectively. Both the fenbendazole and combination groups showed 98% and 99% FECR, respectively, at 14days post-treatment; these reductions dropped slightly at day 29 post-treatment to 94% and 89%, respectively. Primarily Cooperia punctata, Cooperia oncophora and Ostertagia ostertagi larvae were recovered from the coprocultures across all treatment groups. Interestingly, the proportions of C. punctata and C. oncophora essentially demonstrated a post-treatment reversal in the both the fenbendazole and combination treatment groups when comparing days 0 and 29, demonstrating prepatency period differences or a fenbendazole treatment effect.

Effects of fenbendazole on fecal microbiome in BPH/5 mice, a model of hypertension and obesity, a brief report.

Fenbendazole (FBZ) is a common antiparasitic treatment used in research rodent colonies for biosecurity purposes. The effect of this compound has been studied in C57 mice, but never before in a strain of mice that has co-morbidities, such as the blood pressure high (BPH)/5. The BPH/5 mouse is an inbred genetic model of hypertension. While both male and female BPH/5 have high blood pressure, there is a metabolic sexual dimorphism with females displaying key features of obesity. The obese gut microbiome has been linked to hypertension. Therefore, we hypothesized that fenbendazole treatment will alter the gut microbiome in hypertensive mice in a sex dependent manner. To test the influence of FBZ on the BPH/5 gut microbiota, fecal samples were collected pre- and post-treatment from adult BPH/5 mice (males and non-pregnant females). The mice were treated with fenbendazole impregnated feed for five weeks. Post-treatment feces were collected at the end of the treatment period and DNA was extracted, and the V4 region of 16S rRNA was amplified and sequenced using the Illumina MiSeq system. The purpose was to analyze the fecal microbiome before and after FBZ treatment, the results demonstrate changes with treatment in a sex dependent manner. More specifically, differences in community composition were detected in BPH/5 non-pregnant female and males using Bray-Curtis dissimilarity as a measure of beta-diversity (treatment p = 0.002). The ratio of Firmicutes to Bacteroidetes, which has been identified in cases of obesity, was not altered. Yet, Verrucomicrobia was increased in BPH/5 males and females post-treatment and was significantly different by sex (treatment p = 5.85e-05, sex p = 0.0151, and interaction p = 0.045), while Actinobacteria was decreased in the post-treatment mice (treatment p = 0.00017, sex p = 0.5, interaction p = 0.2). These results are indicative of gut dysbiosis compared to pre-treatment controls. Lactobacillus was decreased with FBZ treatment in BPH/5 females only. In conclusion, fenbendazole does alter the gut microbial communities, most notable in the male rather than female BPH/5 mouse. This provides evidence that caution should be taken when providing any gut altering treatments before or during mouse experiments.

Anti-cancer effect of fenbendazole-incorporated PLGA nanoparticles in ovarian cancer.

Fenbendazole (FZ) has potential anti-cancer effects, but its poor water solubility limits its use for cancer therapy. In this study, we investigated the anti-cancer effect of FZ with different drug delivery methods on epithelial ovarian cancer (EOC) in both in vitro and in vivo models. EOC cell lines were treated with FZ and cell proliferation was assessed. The effect of FZ on tumor growth in cell line xenograft mouse model of EOC was examined according to the delivery route, including oral and intraperitoneal administration. To improve the systemic delivery of FZ by converting fat-soluble drugs to hydrophilic, we prepared FZ-encapsulated poly(D,L-lactide-co-glycolide) acid (PLGA) nanoparticles (FZ-PLGA-NPs). We investigated the preclinical efficacy of FZ-PLGA-NPs by analyzing cell proliferation, apoptosis, and in vivo models including cell lines and patient-derived xenograft (PDX) of EOC. FZ significantly decreased cell proliferation of both chemosensitive and chemoresistant EOC cells. However, in cell line xenograft mouse models, there was no effect of oral FZ treatment on tumor reduction. When administered intraperitoneally, FZ was not absorbed but aggregated in the intraperitoneal space. We synthesized FZ-PLGA-NPs to obtain water solubility and enhance drug absorption. FZ-PLGA-NPs significantly decreased cell proliferation in EOC cell lines. Intravenous injection of FZ-PLGA-NP in xenograft mouse models with HeyA8 and HeyA8-MDR significantly reduced tumor weight compared to the control group. FZ-PLGA-NPs showed anti-cancer effects in PDX model as well. FZ-incorporated PLGA nanoparticles exerted significant anti-cancer effects in EOC cells and xenograft models including PDX. These results warrant further investigation in clinical trials.

Fenbendazole treatment against Dentostomella translucida in Syrian golden hamsters

Dentostomella translucida is an oxyurid nematode that was first discovered in the Mongolian gerbil but has also been detected in other wild and housed rodents. In conventional laboratory animals, oxyurid nematode parasites are widespread infections. A proven treatment strategy for pinworm eradication is the oral application of benzimidazoles, such as fenbendazole. In general, this drug is regarded as safe with minimal side effects. Nevertheless, in Sprague Dawley rats, a significantly reduced litter size could be seen after longer treatment with fenbendazole. Even though Dentostomella translucida was already described in Syrian golden hamsters (Mesocricetus auratus), data on treatment with fenbendazole and its effects on reproduction is lacking. Therefore, the main purposes of the study were (1) the verification of the effectiveness of fenbendazole as medicated feed (150 ppm) against this parasite in naturally infected Syrian golden hamsters in conventional husbandry and (2) monitoring of possible effects on reproduction during the treatment. Results show that fenbendazole treatment was highly effective against Dentostomella translucida, as numbers of pinworm eggs in the faeces were significantly reduced already after the first week of treatment in all animals. After four weeks of treatment, eggs were eradicated entirely. Interestingly, the average weaning weight was significantly reduced during treatment, but the litters were in good health.

Fenbendazole Attenuates Bleomycin-Induced Pulmonary Fibrosis in Mice via Suppression of Fibroblast-to-Myofibroblast Differentiation.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal interstitial lung disease with unknown etiology. Despite substantial progress in understanding the pathogenesis of pulmonary fibrosis and drug development, there is still no cure for this devastating disease. Fenbendazole (FBZ) is a benzimidazole compound that is widely used as an anthelmintic agent and recent studies have expanded the scope of its pharmacological effects and application prospect. This study demonstrated that FBZ treatment blunted bleomycin-induced lung fibrosis in mice. In vitro studies showed that FBZ inhibited the proliferation and migration of human embryo lung fibroblasts. Further studies showed that FBZ significantly inhibited glucose consumption, moderated glycolytic metabolism in fibroblasts, thus activated adenosine monophosphate-activated protein kinase (AMPK), and reduced the activation of the mammalian target of rapamycin (mTOR) pathway, thereby inhibiting transforming growth factor-β (TGF-β1)-induced fibroblast-to-myofibroblast differentiation and collagen synthesis. In summary, our data suggested that FBZ has potential as a novel treatment for pulmonary fibrosis.

Inclusion of Sainfoin in the Diet Might Alter Strongyle Infection in Naturally Infected Horses.

It is increasingly difficult to control equine strongyles with synthetic drugs, as resistance is commonly observed. Here, we investigated the possible anthelmintic effect of sainfoin (Onobrychis viciifolia), a polyphenol-rich legume, in naturally infected horses. On Day 0 (D0), 17 horses were allocated to three different homogenous groups in terms of fecal egg count (FEC): the control group (CONT) received a diet composed on a DM basis of 83% hay and 17% wheat bran, while in the sainfoin 1 (SF1) and sainfoin 2 (SF2) groups, half or all wheat bran, respectively, was replaced by dehydrated sainfoin pellets. The infection dynamics were monitored by weekly FEC, from D0 to D84. On D28, all horses were treated with fenbendazole. Larval motility was assessed from coprocultures at D0, D28, D56 and D84. Horses in Group SF2 had lower FEC from D7 to D28. After fenbendazole treatment, no effect of the diet was measured on FEC. Both before and after anthelmintic treatment, larvae from horses consuming sainfoin were less motile than larvae from the CONT group. These results suggest that sainfoin has an in vivo anthelmintic activity in naturally infected horses, although this effect appears to be context-dependent.

G2/M arrest and mitotic slippage induced by fenbendazole in canine melanoma cells.

BackgroundThe use of fenbendazole (FBZ) in terminal cancer patients has recently increased, as anthelminthic drugs, such as FBZ and benzimidazole, exhibit anti‐tubulin effects in tumour cells.ObjectivesThe present study evaluated the in vitro anti‐cancer effects of FBZ in five canine melanoma cell lines originating from the oral cavity (UCDK9M3, UCDK9M4, UCDK9M5, KMeC and LMeC).MethodsFive canine melanoma cell lines were treated with FBZ and analysed with cell viability assay, cell cycle analysis, western blot assay and immunofluorescence staining to identify apoptotic effect, cell cycle arrest, microtubule disruption and mitotic slippage.ResultsCell viability was reduced in all melanoma cell lines in a dose‐dependent manner after FBZ treatment. Through cell cycle analysis, G2/M arrest and mitotic slippage were identified, which showed a time‐dependent change. All treatment concentrations induced increased cleaved PARP signals in western blot analysis compared to the control groups. Immunofluorescence of cells treated for 24 h revealed defects in microtubule structure, multinucleation or macronucleation. With the exception of UCDK9M3, the melanoma cells showed mitotic slippage and post‐slippage death, indicative of mitotic catastrophe.ConclusionsThese results indicate that FBZ exhibits anti‐cancer effects in vitro against canine melanoma cells; however, further in vivo studies regarding the clinical applications of FBZ are required.

Lack of efficacy of fenbendazole against Giardia duodenalis in a naturally infected population of dogs in France.

Giardiosis is a worldwide intestinal parasitosis, affecting both humans and animals. Treatment in dogs remains limited and the lack of efficacy of the few approved medications is a rising concern. In this study, 23 dogs raised by veterinary students and naturally infected with Giardia duodenalis were treated in home conditions with fenbendazole (50mg/kg orally for 5 consecutive days). Fecal samples were collected immediately before treatment (FS1), 2-4days after treatment (FS2) and 8-10days after treatment (FS3). Giardia duodenalis cyst excretion was measured quantitatively by direct immunofluorescence assay (DFA) at FS1, FS2 and FS3. Molecular typing with a nested PCR targeting the SSU rDNA locus was also performed at FS1 and FS2. Fecal consistency improved in 16/21 dogs (76%) and mean cyst shedding was reduced by 84% after treatment. However, only 8/23 dogs (35%) achieved therapeutic success (≥90% reduction of cysts) and only 4/23 dogs (17%) had complete elimination of G. duodenalis. Molecular typing showed that dogs harbored only canine-specific assemblages, with a high prevalence of assemblage C in analyzed samples (30/39). We also detected different assemblages after treatment and nucleotide substitutions in assemblage C sequences that have not been described previously. Eight to ten days after treatment, high Giardia cyst excretion was measured, suggesting possible reinfection despite hygiene measures and/or multiplication. These data suggest that fenbendazole treatment may improve fecal consistency but has limited therapeutic efficacy against giardiosis in this population of dogs. Further research is still needed to assess the efficacy of fenbendazole against canine giardiosis.

Effects of Maternal Fenbendazole on Litter Size, Survival Rate, and Weaning Weight in C57BL/6J Mice.

Fenbendazole is a broad-spectrum benzimidazole commonly used in laboratory animal medicine as an anthelmintic for elimination of pinworms. This drug is generally regarded as safe, with minimal side effects. Some data in rodent species indicate multiple physiologic effects of fenbendazole, including changes in immune parameters and behavior, but no studies to date have evaluated possible effects on reproduction in mice. The purpose of the current study was to determine the effects of several treatment regimens of fenbendazole on reproductive parameters in C57BL/6J mice. Uninfected mice were given fenbendazole-treated feed continuously or every other week until pups were born or weaned. This treatment also was combined with environmental decontamination. No significant differences in litter size, survival rate, or weaning weight were detected between groups. Under the conditions of this study, fenbendazole treatment does not affect reproduction in C57BL/6J mice.

PSXV-21 Assessment of the presence of anthelmintic resistance in Maryland beef cattle herds

Abstract Reduced anthelmintic efficacy in beef cattle has recently been documented at the national level. The objective of this study was to determine if anthelmintic resistance is present in Maryland beef cattle herds. For this study, the fecal egg count reduction (FECR) test was used to assess anthelmintic efficacy of composite samples. Between July and October 2020, anthelmintic efficacy was assessed for 17 groups of cattle across 14 individual farms in Maryland. Each test group consisted of 24 ± 6 calves or yearlings (< 16 months of age). Previous anthelmintic treatment history was used to assign each group to one of four commercially available anthelmintics: moxidectin (injectable), moxidectin (pour-on), doramectin, or fenbendazole. Prior to treatment, cattle were weighed to ensure appropriate dose according to the product label. Fecal samples were collected from all cattle within each group before and after (17 ± 5 d) treatment. Pre- and post-treatment samples were composited for each group on an equal-weight basis (10g per animal) and the number of eggs within the sample was determined using the 3-chambered McMaster technique. The mean FECR across all four anthelmintics was 60 ± 19% (mean ± 95% confidence interval), indicating that the anthelmintics tested in this study were largely ineffective. The FECR for the moxidectin injectable, moxidectin pour-on, doramectin, and fenbendazole treatments were 71 ± 38%, 47 ± 46%, 35 ± 88%, and 96 ± 18% (mean ± 95% confidence interval), respectively. Although these data indicate no statistically significant differences for efficacy among the four products tested, they do suggest that efficacy is highly variable across different anthelmintics and farms. Results also indicate that anthelmintic resistance exists on many cattle farms in Maryland. This study provides evidence that supports the need for more judicious anthelmintic use and alternative gastrointestinal parasite control measures in Maryland beef cattle herds.

Parascaris univalens – first case of fenbendazole treatment failure in Sweden, with enhanced efficacy of a combination treatment with ivermectin

<i>Parascaris univalens</i> – first case of fenbendazole treatment failure in Sweden, with enhanced efficacy of a combination treatment with ivermectin

146 Fecal egg count reduction in juvenile and mature horses administered fenbendazole or moxidectin/praziquantel dewormer

Parasite resistance is a concern in horses and can be monitored by performing fecal egg counts (FECs). Unfortunately, FECs are not performed regularly, which could contribute to developing anthelmintic resistance as it may lead to deworming too frequently or not using an effective dewormer for the horse. This study aims to evaluate the ability of pellet and paste fenbendazole (FBZ) and a paste moxidectin/praziquantel (MOX/PZQ) dewormer to reduce parasite populations in juvenile and mature horses in River Falls, Wisconsin. To evaluate dewormers, horses with an initial FEC ≥50 eggs per gram (EPG) were used. For FBZ, horses were blocked by shedding level as low (<200 EPG), moderate (200 – 500 EPG), and high (>500 EPG) shedders and assigned to the pellet (n = 21) or paste (n = 23) FBZ treatment. Two-weeks post-treatment, another FEC was taken and a fecal egg count reduction (FECR) was calculated. Eight-weeks following this study, another FEC was performed and horses with ≥50 EPG were administered a MOX/PZQ paste (n = 46). Two-weeks post-treatment, another FEC was taken and subsequent FECR was calculated. Results from this study indicated no differences were observed for horses receiving pellet or paste FBZ with a FECR of 57.4% and 65.7%, respectively ( P ≥ 0.05). Additionally, no difference in the FECR for juvenile versus mature horses or shedding level was observed regardless of the dewormer used ( P ≥ 0.05). While both FBZ and MOX/PZQ reduced FECs when comparing the pre- and post-treatment EPG ( P ≤ 0.01), the average FECR was 60.4% and 98.5% for horses receiving FBZ and MOX/PZQ, respectively. These results demonstrate parasite resistance to FBZ was observed in this herd while MOX/PZQ was still effective in reducing FECs.

Reduced Efficacy of Fenbendazole and Pyrantel Pamoate Treatments against Intestinal Nematodes of Stud and Performance Horses.

Nematodes are an important cause of disease and loss of performance in horses. Changes in the parasitic fauna of horses have occurred in the past few decades, making cyathostomins the major parasites in adult horses, while large strongyles have become less prevalent. Parascaris spp. remains the most important parasite infecting foals and weanlings. Anthelmintic resistance is highly prevalent in cyathostomins and Parascaris spp. worldwide and it must be factored into treatment decisions. To assess anthelmintic efficacy in Northern Italy, we sampled 215 horses from 17 sport and horse-breeding farms. Fecal egg count reduction tests (FECRT) were used to assess anthelmintic efficacy. Copromicroscopic analysis was performed using MiniFLOTAC before treatment with fenbendazole, pyrantel pamoate or ivermectin, and repeated 14 days post-treatment. Strongyle-type eggs were detected in 66.91% of horses (CI95% 61.40–73.79%), while Parascaris spp. was detected in 2.79% (CI95% 1.94–5.95%). Reduced efficacy against cyathostomins was observed for fenbendazole in 55.56% of the treated animals (CI95% 41.18–69.06%), and for pyrantel pamoate in 75% of animals (CI95% 30.06–95.44%). Ground-based actions must be set in place to promote the uptake of state-of-the-art worm control plans that will prevent clinical disease while minimizing the selection pressure of resistant parasites.

Health assessment of wild speckled dwarf tortoises, CHERSOBIUS SIGNATUS

BackgroundIn free-ranging reptile populations, bacterial, fungal, viral and parasitic pathogens may affect hosts through impairment in movements, thermoregulation, reproduction, survival, and population dynamics. The speckled dwarf tortoise (Chersobius [Homopus] signatus) is a threatened species that is mostly restricted to the Succulent Karoo biome in South Africa, and little information on pathogens of this species is available yet. We derived baseline parameters for five males and five females that were captured to genetically enhance a conservation breeding program in Europe. Upon collection of the tortoises, ticks were removed and identified. Immediately upon arrival in Europe, ocular, nasal, oral and cloacal swabs were taken for viral, bacteriological and mycological examinations. Fecal samples were collected before and 1 month after fenbendazole treatment, and analyzed for parasites. A panel of PCR, aiming to detect herpesviruses, adenoviruses and iridoviruses, was carried out.ResultsSamples were negative for viruses, while bacteriological examination yielded detectable growth in 82.5% of the swabs with a mean load of 16 × 107 ± 61 × 108 colony forming units (CFU) per swab, representing 34 bacterial species. Cloacal and oral swabs yielded higher detectable growth loads than nasal and ocular swabs, but no differences between sexes were observed. Fungi and yeasts (mean load 5 × 103 ± 13 × 103 CFU/swab) were detected in 25% of the swabs. All pre-treatment fecal samples were positive for oxyurid eggs, ranging from 200 to 2400 eggs per gram of feces, whereas after the treatment a significantly reduced egg count (90–100% reduction) was found in seven out of 10 individuals. One remaining individual showed 29% reduction, and two others had increased egg counts. In five tortoises, Nycthocterus spp. and coccidian oocysts were also identified. Soft ticks were identified as Ornithodoros savignyi.ConclusionsOur baseline data from clinically healthy individuals will help future studies to interpret prevalences of microorganisms in speckled dwarf tortoise populations. The study population did not appear immediately threatened by current parasite presence.

Anthelmintic efficacy of fenbendazole and levamisole in native fowl in northern Iran

BackgroundWith the increasing number of free-range domestic chickens, helminth parasites have potentially become more of a threat to commercial flocks in recent years, and routine poultry deworming is needed to improve the efficiency of chicken production. The present study deals with a field trial to study the efficacy of two generally used anthelmintics, fenbendazole and levamisole, against gastrointestinal nematodes of domestic chickens in northern Iran.MethodsOf 45 domestic chicken flocks involved in the study, 20 flocks were selected to participate in fecal egg count reduction testing based on flock size from April 2017 to September 2018. The infected chickens were randomly divided into three equal groups of 30 each. Ninety chickens in the infected groups received one of the following treatments (d 0 of treatment): Group 1: 5 mg kg−1 body weight (BW) fenbendazole for 3 consecutive days; Group 2: 16 mg kg−1 BW levamisole; Group 3 control: placebo, water + DMSO (dimethylsulfoxide). The efficacy of the treatments was evaluated by comparing fecal egg counts in the treated and control groups.ResultsExamination of three flocks of chickens from the control group showed that 95.0% of the animals were infected with gastrointestinal nematodes with an average geometric value of 361 eggs per gram of feces. Fenbendazole at a dose of 5 mg kg−1 BW for 3 days showed an efficacy of 83.7% (P ≥ 0.05), and levamisole at a dose of 16 mg kg−1 BW showed 71.8% efficacy (P ≥ 0.05) with geometric mean eggs in a gram of feces of 100 and 199.6, respectively. In general, fenbendazole and levamisole treatment led to significantly lower activity. The result of this study revealed that fenbendazole was a better and more effective dewormer than levamisole on the three Iranian domestic chicken flocks, but the difference was not significant. Capillaria spp. were the most generally resistant nematodes followed by Trichostrongylus spp. and Amidostomum anseris.ConclusionOur results indicated that fenbendazole and levamisole effectively reduced the number of nemathodes in three Iranian domestic chicken flocks. Given the results of our study, resistance can be expected in the parasitic helminths of poultry. Additional larger scale studies are required to determine the prevalence of anthelmintic resistance in the poultry industry.Graphical

Involvement of reactive oxygen species in the anti-cancer activity of fenbendazole, a benzimidazole anthelmintic

Fenbendazole (FBZ) is a benzimidazole anthelmintic that has been widely used in treatments for gastrointestinal parasites including pinworms and roundworms in animals. Recently, some studies demonstrated that FBZ has anti-cancer effects related to disruption of microtubule polymerization. In this study, we investigated whether FBZ has anti-cancer activity in HL-60 cells, a human leukemia cell line, and assessed its relationship with the production of reactive oxygen species (ROS). FBZ treatment at 0.25-1 μM significantly decreased the metabolic activity of HL-60 cells. The mitochondrial membrane potential of FBZ-treated HL-60 cells decreased in a concentration-dependent manner. Apoptosis analysis using annexin V-FITC/propidium iodide staining demonstrated that 1 μM FBZ increased the percentages of cells in apoptosis and necrosis. In addition, Hoechst 33342 staining showed the presence of broken nuclei in HL-60 cells treated with 0.5 and 1 μM FBZ. To investigate the anti-cancer mechanism of FBZ, HL-60 cells were treated with FBZ in the absence or presence of N-acetyl cysteine (NAC), an inhibitor of ROS production. NAC significantly recovered the decreased metabolic activity of HL-60 induced by 0.5 and 1 μM FBZ treatments. This study provides evidence that FBZ has anti-cancer activity in HL-60 cells provided, in part, via ROS production. Keywords: fenbendazole, anti-cancer activity, HL-60 cells, reactive oxygen species, N-acetyl cysteine

Evaluation of the effects of anthelmintic administration on the fecal microbiome of healthy dogs with and without subclinical Giardiaspp. and Cryptosporidium canisinfections.

BackgroundThe gastrointestinal microbiome plays an important role in host health and there is increasing concern regarding the deleterious effects of pharmaceuticals on the fecal microbiome. The effect of anthelmintic therapy on the fecal microbiome in dogs has not yet been evaluated. The purpose of this study was to evaluate the effect of anthelmintic administration on the fecal microbiome of dogs with and without subclinical Giardia species and Cryptosporidium canis infections.Methodology/Principal findingsPart 1: 6 healthy adult research beagles with subclinical giardiasis and cryptosporidiosis were administered a commercially available preparation of febantel combined with pyrantel and praziquantel (FPP) orally daily for three days. Part 2: 19 healthy staff-owned dogs without giardiasis or cryptosporidiosis were divided into a treatment group (n = 9) that was administered fenbendazole orally daily for five days and an untreated control group (n = 10). For both parts of the study, feces were collected at multiple time points before and after anthelmintic (FPP or fenbendazole) administration. Fecal DNA was extracted for Illumina sequencing of the bacterial 16S rRNA gene and qPCR assays. Neither FPP nor fenbendazole treatment caused a significant change in alpha or beta diversity or the relative abundance of bacterial species. Upon univariate statistical analysis neither FPP or fenbendazole caused minimal changes in the fecal microbiota.ConclusionFPP administration was associated with minimal alterations of the fecal microbiome of healthy research beagles with subclinical giardiasis and cryptosporidiosis. Fenbendazole administration was associated with minimal alterations of the fecal microbiome of healthy staff owned dogs.