Reduction In Worm Counts Research Articles

Efficacy of Bravecto\xae Plus spot-on solution for cats (280 mg/ml fluralaner and 14 mg/ml moxidectin) for the prevention of aelurostrongylosis in experimentally infected cats

BackgroundThe feline lungworm Aelurostrongylus abstrusus affects the lower respiratory tract in cats worldwide. As infections may lead to chronic respiratory changes or even death, preventive treatment in cats with outdoor access is warranted.MethodsThe preventive efficacy of a spot-on solution (Bravecto® Plus spot-on solution for cats, MSD) against cat aelurostrongylosis was evaluated using three different preventive treatment regimes in a negative controlled, randomized and partially blinded laboratory efficacy study with 31 purposed-bred cats. The minimum recommended dose of 2.0 mg moxidectin + 40 mg fluralaner/kg bodyweight was applied once 12 (Group [G]1), 8 (G2) or 4 (G3) weeks before experimental infection with 300 third-stage larvae (L3) of A. abstrusus. Another group served as untreated control (G4). Individual faecal samples were analysed as of day 30 post infection (pi) to monitor larvae excretion. Necropsy was performed at days 47–50 pi. The lungs were examined macroscopically for pathological findings and (pre-)adult worms were counted to assess preventive efficacy.ResultsBeginning at day 32–40 pi, all cats of the control group were constantly shedding larvae of A. abstrusus, whereas only one animal of G1 excreted larvae at several consecutive days. In addition, two cats of G1 and G3 and three of G2 were positive on a single occasion. The geometric mean (GM) of the maximum number of excreted larvae was 7574.29 in the control group compared to 1.10 (G1), 1.19 (G2) and 0.53 (G3), resulting in a GM reduction of > 99.9% in all treatment groups. All lungs of the control animals showed severe or very severe alterations at necropsy, while in 94.44% of the treated cats lung pathology was rated as absent or mild. The GM number of (pre-)adult A. abstrusus retrieved from the lungs was 26.57 in the control group, 0.09 in G1 and 0.00 in G2 and G3. Thus, GM worm count reduction was 99.66% in G1 and 100% in G2 and G3.ConclusionsA single application of Bravecto® Plus spot-on solution at a dose of 2.0 mg moxidectin + 40 mg fluralaner/kg bodyweight reliably prevents cat aelurostrongylosis for at least 12 weeks.Graphical

Antischistosomal and antioxidant protective role of Carica papaya fruit extracts against Schistosoma mansoni

Schistosomiasis is a major disease of public health in human. Patterns on immune response, worm recovery, in vitro antischistosomal bioassay screening (cercaricidal killing in vitro of Schistosoma mansoni was observed). In vivo Mice were infected by injection of 100 S. mansoni cercariae/mouse and treated by oral administration with crude extract, MeOH, ethyl acetate (EtOAc) and butanol (BuOH) Carica papaya fruits (4g/kg) start from 7th day p.i. to the end of experiment and a treatment control of 500 mg/kg of Praziquantel. Various concentrations of plant extracts were used in cercaricidal assay. Both crude extract and EtOAc showed significant dose-dependent percentage worm load reduction (P<0.001). Carica papaya, showed highly reduction in worm counts (60.3% and 68.2%) while Praziquantel (92.8%), elevated immune responses and least time in destroying cercariae. The highest significant reduction in dead ova (P<0.001) was observed in group treated with EtOAc extract. The level of IgG1 and IgG2 was significantly reduced (P<0.001) than in groups treated with C. papaya crude extract, EtOAc extract or PZQ as compared to levels in untreated infected mice. While the level of IgG1 and IgG2 was insignificantly reduced in groups treated with MeOH extract or BuOH extract as compared to levels in untreated infected mice. It was concluded from the results that the antischistosomal efficacy of the extracts was dependent being more potent in reducing both the worm burden and tissue egg load. The antishistosomal effect of C. papaya extracts was significantly higher in group treated with EtOAc extract. These findings supporting the potential use of C. papaya extracts in the management of schistosomiasis.

Evaluation of in vitro and in vivo anthelmintic efficacy of Cyperus compressus Linn., a traditionally used anthelmintic plant in parasite-animal models

BackgroundThe decoction of the roots of Cyperus compressus (Cyperaceae) is used to treat helminth infection by the Santhal tribe of Assam. The study evaluated the anthelmintic efficacy claims of the plant C. compressus through pre-clinical in vitro and in vivo studies employing available parasite-animal models such as Hymenolepis diminuta-Wistar rat (cestode) and Syphacia obvelata-Swiss mice (nematode) models.ResultsPhytochemical analysis revealed the presence of alkaloids, glycosides, reducing sugars, flavonoids, terpenoids, tannins, and steroids. In vitro studies were conducted employing H. diminuta and S. obvelata. In vitro studies against H. diminuta revealed mortality of parasites at 8.3 ± 0.05 h at the highest concentration of C. compressus methanolic root extract (30 mg/ml), whereas reference drug praziquantel (PZQ), showed mortality at 5.84 ± 0.01 h. Against S. obvelata, in the same concentration of the extract, mortality of parasites occurred in a much later time of 24.13 ± 0.03 h, whereas in the reference drug albendazole (ABZ), the parasites showed mortality at 7.24 ± 0.08 h. In vivo studies against H. diminuta revealed 61.74% reduction in the eggs per gram (EPG) counts and 24% reduction in worm counts at the highest dose of 700 mg/kg body weight (b.w.) of plant extract. Against S. obvelata, at 700 mg/kg b.w., 28.92% and 33.85% reduction in EPG and worm counts were recorded respectively.ConclusionAlthough the reference drugs showed better in vitro and in vivo efficacy, the plant extract showed a better in vitro efficacy against cestode parasite compared to its nematode counterpart indicating that it possesses a better cestocidal efficacy. EPG reductions were higher against H. diminuta, whereas worm count reduction was higher against S. obvelata. The findings justify the use of C. compressus as an anthelmintic in the traditional medicine of the Santhals of India.

EVALUATION OF THE EUCALYPTUS CAMALDULENSIS-KILLED CERCARIAE AS A CANDIDATE VACCINE FOR EXPERIMENTAL SCHISTOSOMIASIS MANSONI

Schistosomiasis is the second commonest parasitic disease worldwide. It is responsible for thousandsof deaths per year in addition to the associating serious morbidities that burden both individuals andcommunities. To date, the main preventive measure of infection is mass treatment with praziquantel. itcarries the risk of reinfection and rising resistance which makes the discovery of an effective vaccinean urgent necessity. The present study evaluated E. camaldulensis killed cercariae immunogen (KCI)as a candidate vaccine for experimental schistosomiasis mansoni and to detect the possible immunologicalmechanisms of action of this immunogen. The KCI caused a significant reduction of bothschistosomula and adult worm counts with subsequent ova count reduction. Hepatic granulomas werereduced in number or size. Also, levels of IgG, IgG1 & IgG2a as well as INF-γ & IL-10 fluctuatedlarger than in natural infection.

Chemical analyses and evaluation of the anthelmintic effects of Origanum majorana essential oil, in vitro and in vivo studies

Because of the development of resistance in helminths against major anthelmintic drugs, the search for alternatives is necessary. Medicinal plants are being studied as an alternative source of anthelmintics against gastrointestinal nematodes. The objective of this study is to analyse the chemical composition and evaluate the anthelmintic efficacy of Origanum majorana essential oil. The determination of the chemical composition by gas chromatography/mass chromatography (GC/MS) revealed that the essential oil was dominated by terpenoids, particularly carvacrol (35.65%) and terpenic hydrocarbons p-cymene (15.82%). The in vitro anthelmintic effects against Haemonchus contortus were assessed by an egg hatch assay (EHA) and an adult worm motility assay (AWMA) compared with the reference drug albendazole. The essential oil showed ovicidal activity at all the tested concentrations (1, 2, 4 and 8 mg/ml) and more than 80% egg hatching inhibition was observed at the highest dose (8 mg/ml). Exposure to 0.5 mg/ml of the essential oil for eight hours induced a 50% inhibition in the worm motility. The in vivo study was performed on H. polygyrus by measuring the egg count reduction (ECR) and adult worm count reduction (AWCR) following the treatment of the animals with different doses (2 000, 4 000 and 5 000 mg/kg) of the plant essential oil, and 22 mg/kg of albendazole as the positive control. The results showed that 5 000 mg/kg of the essential oil inhibited the egg count and adult worm count by 76.3 and 74.0%, respectively, seven days post treatment. These findings support the possible use of O. majorana essential oil to control gastrointestinal nematodes.

In vitro and in vivo anthelmintic study of Sesbania sesban var. bicolor, a traditionally used medicinal plant of Santhal tribe in Assam, India.

The leaf decoction of Sesbania sesban var. bicolor is used traditionally by Santhal tribe of Assam, India, for the treatment of intestinal helminthic infections. This study was conducted to evaluate the in vitro and in vivo anthelmintic efficacy of methanolic extract of S. sesban var. bicolor leaves using Hymenolepis diminuta-rat (cestode) and Syphacia obvelata-mice (nematode) as test parasites and models. Praziquantel (PZQ) and albendazole (ABZ) were used as reference drugs. At the highest concentration of 30mg/ml of the plant extract, H. diminuta and S. obvelata showed mortality at 0.81 ± 0.01h and 15.17 ± 0.05h, respectively. The in vivo results substantiated the in vitro findings, and the extract showed a better cestocidal efficacy in a dose-dependent manner, whereby treatment of rats with 400mg/kg of the plant extract caused 65.10% reduction in eggs per gram (EPG) of faeces and 56% reduction in worm counts. S. obvelata-infected mice treated at the same dose showed 34.32% and 47.08% reduction in EPG and worm counts at necropsy, respectively. The methanolic extract was subjected to bioassay-guided fractionation using different solvents and the ethyl acetate fraction proved to be the most active. This active fraction was subjected to column chromatography using varying concentrations of hexane:ethyl acetate. Maximum efficacy was observed in 7:3 hexane:ethyl acetate, where H. diminuta and S. obvelata showed mortality at 3.56 ± 0.12h and 9.21 ± 0.02h, respectively. This indicates that the isolated fraction contained the active component responsible for its anthelmintic activity, which substantiates the medicinal usage in traditional practice.

Efficacy of orally administered combination of moxidectin, sarolaner and pyrantel (Simparica Trio\u2122) for the prevention of experimental Angiostrongylus vasorum infection in dogs

BackgroundInfection with Angiostrongylus vasorum may cause severe clinical disease, even death in dogs, however, due to the often non-specific clinical signs, diagnosis is not always straightforward. Regular prophylactic treatment may offer a safe means to protect dogs against infection. The efficacy of a novel oral endectocide containing moxidectin, sarolaner and pyrantel was investigated for the prevention of angiostrongylosis in dogs in three placebo-controlled, randomized, masked studies. The initial study (Study 1) determined the efficacious dosage of moxidectin in the combination product by evaluating three different dose levels, and two follow-up studies (Studies 2 and 3) confirmed the efficacy of the selected moxidectin dose.MethodsAnimals were infected orally with 200 infective third-stage larvae (L3) of A. vasorum and were treated 28 days later with the combination product or with placebo. Timing of dosing relative to infection allowed for efficacy to be evaluated against the immature adult (L5) stage. Dogs in Study 1 received treatments with oral tablets to deliver 3, 12 or 24 µg/kg moxidectin in combination with 2 mg/kg sarolaner and 5.0 mg/kg pyrantel (as pamoate salt) or placebo. In Studies 2 and 3, Simparica Trio™ tablets were administered to provide minimum dosages of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5.0 mg/kg pyrantel (as pamoate salt). Efficacy of the combination product was calculated as the percent reduction in adult worm counts at necropsy relative to placebo.ResultsIn Study 1, the 3, 12 and 24 µg/kg moxidectin dosage in the combination product provided 7.2%, 54.5% and 94.7% efficacy against the immature adult stages of A. vasorum, respectively. Studies 2 and 3 confirmed that the efficacy of 24 µg/kg moxidectin combined with 1.2 mg/kg sarolaner and 5 mg/kg pyrantel in Simparica Trio™ was ≥ 92.9%. All three studies established that a single oral administration of 24 µg/kg moxidectin in the combination product provided effective prophylactic treatment for angiostrongylosis, reduced L1 production and fecal excretion and minimized the tissue damage to the lungs.ConclusionsA single oral treatment of dogs with Simparica Trio™ providing moxidectin at a minimum dose of 24 µg/kg was efficacious in the prevention of angiostrongylosis.

Hydro-Ethanolic Extract of Mentha pulegium Exhibit Anthelmintic and Antioxidant Proprieties In Vitro and In Vivo.

During recent decades, the emergence of chemoresistance among synthetic anthelmintic drugs has increased the interest in screening novel natural anthelmintic compounds derived from plants. The current study is aimed to determine the chemical profile, anthelmintic and antioxidant properties of Mentha pulegium hydro-ethanolic extract. Two tests were used to assess the in vitro anthelmintic activity of the hydro-ethanolic extract of M. pulegium against Haemonchus contortus; egg hatch assay (EHA) and adult worm motility (AWM) assay. M. pulegium extracts at the doses of 500, 1000, 2000 and 4000 mg/kg were evaluated in vivo in mice infected with Heligmosomoides polygyrus. The anthelmintic efficacy was monitored using faecal egg count reduction (FECR) and total worm count reduction (TWCR). The antioxidant activity of M. pulegium extract was evaluated by testing the total antioxidant capacity and the DPPH free radical-scavenging ability. Chromatographic characterization of M. pulegium composition using RP-HPLC revealed the presence of phenolic acids such as syringic acid, ferulic acid and the presence of flavonoid compounds, such as isorhamnetin-3-O-glucoside and kaempferol-3-O-rutinoside. We observed 91.58% inhibition in the EHA at 8 mg/mL after 48 h of incubation (IC50=1.82 mg/mL). In the AWM assay, M. pulegium extract achieved 65.2% inhibition at 8 mg/mL after 8 h. The highest dose (4000 mg/kg) showed a significant nematicidal effect 7 days post-treatment by inducing 60.39% FECR and 71.6% TWCR. We also report strong in vivo antioxidant capacity of the extract, as revealed by a significant increase of the enzymatic activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes in mice infected with H. polygyrus. Together, the results in this paper suggest that M. pulegium possesses anthelmintic properties and could be a potential source of novel compounds for the control of helminth parasites as well as its associated oxidative damage.

Assessment of the potential therapeutic effects of omeprazole in Schistosoma mansoni infected mice.

Schistosomiasis is a neglected chronic parasitic disease with a significant lasting morbidity. Currently, praziquantel (PZQ) is the most efficient drug for schistosomiasis worldwide. However, the possibility of the occurrence of resistance to PZQ is increasing. Therefore, there is a vital need to find new antischistosomal drugs or to increase the efficacy of the existing ones. Omeprazole is a proton pump inhibitor which is reported to have antiparasitic properties. Thus, the aim of this study was to assess the potential therapeutic effects of omeprazole in experimental Schistosoma mansoni infection either alone or in combination with PZQ. For this aim, 80 laboratory bred mice were divided into 3 groups; uninfected control, infected untreated control, and infected and treated at tenth week P.I. The last group was divided into three subgroups that received either PZQ alone, omeprazole alone, or both drugs. The effectiveness of treatment was assessed by adult worm counts, liver egg count, scanning electron microscopy of adult worms, histopathological, and immunohistochemical (GFAP) examination. There was significant reduction of adult worm counts, liver egg counts, size, diameter of hepatic granulomas, hepatic fibrosis, and GFAP expression in the group that received combined treatment as compared to PZQ group. Moreover, the tegumental changes were more evident in the group that received combined treatment. In conclusion, the administration of omeprazole with PZQ improved the efficacy of PZQ in the treatment of Schistosomiasis mansoni.

Effectiveness of the spot-on combination of moxidectin and imidacloprid (Advocate\xae) in the treatment of ocular thelaziosis by Thelazia callipaeda in naturally infected cats

BackgroundThe present study evaluated the therapeutic effectiveness of moxidectin 1.0% (w/v) and imidacloprid 10% (w/v) (Advocate® spot-on solution for cats, Bayer Animal Health) against natural infections with the eyeworm Thelazia callipaeda in cats. This study was conducted as a GCP, negative-controlled, blinded and randomised field study in privately owned cats living in an area in southern Italy where T. callipaeda is enzootic.MethodsThe study was carried out in 30 cats (19 females and 11 males, aged from 8 months to 5 years, weighing 1.2–5.2 kg) of different breeds, naturally infected by T. callipaeda. At study inclusion (Day 0), animals were physically examined and the infection level was assessed by examination of both eyes for clinical score and live adult T. callipaeda count. Each cat was weighed and randomly assigned to one of the treatment groups (G1: Advocate, G2: untreated control). Clinical assessments and T. callipaeda adult counts were performed on Day 14. At the study completion visit on Day 28, clinical assessments and counts of T. callipaeda adults and larvae were performed. All cats were daily observed by their owners and general health conditions were recorded during the entire period of the study.ResultsThe primary effectiveness variable was the percentage of animals in G1 group (Advocate) showing a complete elimination (parasitological cure) of adult eye worms at Day 14 and Day 28 . The effectiveness of the treatment in the G1 group was 93.3 and 100% at Day 14 and Day 28 , respectively, when compared to group G2. Total worm count reduction from both eyes for Advocate was 96.3% on Day 14 and 100% on Day 28. Clinical data were confirmed by the examination of conjunctival pouch flushing. An overall reduction in the number of cats with lacrimation and conjunctivitis was observed following treatment despite the fact that in a few cats treated with Advocate clinical signs persisted due to the chronic nature of the disease.ConclusionsBased on the results of the present trial, a single dose of Advocate was found to be safe and highly effective in the treatment of natural T. callipaeda infection in cats.

Chemical analyses and anthelmintic effects of Artemisia campestris essential oil

The present study aimed at analyzing the chemical composition and evaluating the in vitro and in vivo anthelmintic activity of Artemisia campestris essential oil aerial parts. The chemical composition was analysed by gaz chromatography/mass chromatography (GC/MS). Fifty compounds were identified representing 99.98% of the total oil. A. campestris essential oil was dominated by beta-pinene (36.40%) and 2-undecanone (14.7%).The in vitro anthelmintic activity tests of A. campestris essential oil were performed on Haemonchus contortus using egg hatch assay (EHA) and adult worm’s motility assay (AWMA) compared with a reference drug albendazole. In the EHA 100% inhibition was observed at 2 mg/ml after 48 h incubation (IC50 = 0.93 mg/ml). In the AWMA, essential oil induced 66.6% inhibition at 0.5 mg/ml after 8 h post exposure.The nematicidal effect of essential oil was evaluated on Heligmosomoides polygyrus. It was monitored through faecal egg count reduction (FECR) and total worm count reduction (TWCR). Three doses (2000, 4000 and 5000 mg/kg) were studied using a bioassay. The dose of 5000 mg/kg showed a high nematicidal activity (72.1% FECR and 72% TWCR), 7 days post-treatment. The results of the present study suggest that A. campestris essential oil has a potential anthelmintic activity and further studies are required in order to establish its mechanisms of action.

Anthelmintic efficacy and safety of selected medicinal plants against mixed gastrointestinal nematodes in artificially infected sheep

There has been widespread resistance to anthelmintics by pathogenic helminths to an extent where there is multi-drug resistance against all major classes of conventional anthelmintics. This world-wide phenomenon calls for urgent search for different approaches to the control of helminthosis including novel anthelmintic products. The purpose of the study was to determine the efficacy and safety of selected plants, which are frequently used in the treatment and control of helminthosis, in artificially infected sheep under controlled laboratory conditions. The selected plant species were, Albizia anthelmintica Brongn, Embelia schimperi L., Myrsine africana L. and Rapanea melanophloeos (L.) Mez. Thirty six male Dorper lambs, aged between 6 and 8 months, artificially infected with mixed gastrointestinal nematodes (GIN) under controlled laboratory conditions, were used for the study. Efficacy was determined using percentage fecal egg count reduction test (FECRT %) and percentage total worm count reduction (TWCR %). Safety of the remedies was assessed using health, hematological and biochemical parameters. The FECR % against the mixed gastrointestinal nematodes was -55, 7.6, 34.2, 69.3 and 83.3% for Albizia anthelmintica, Embelia schimperi, Rapanea melanophloeos, albendazole and Myrsine africana respectively. TWCR% of 60.7, 44.6, 66, 69.7 and 35.6 percent were recorded for Albizia anthelmintica, Embelia schimperi, Myrsine Africana, Rapanea melanophloeos, and albendazole groups respectively. It was concluded that some of the remedies like M. africana have good efficacy at safe levels and should further be evaluated to determine the most optimum dosages. The gastrointestinal nematodes used in this study were resistant to albendazole.

Efficacy of Purified Glutathione -S- Transferee in Providing Protection against Haemonchus Contortus Infection in Sheep

The efficacy of purified glutathione-s-transferase (GST) to protect sheep against haemonchosis was assessed. Fifteen lambs, 3.5-5month-old, were bisected into five groups (n=3). Two groups were vaccinated with 250μg of each prepared antigen (crude adult antigen (CAA), purified GST) in combination with mineral oil adjuvant at zero, 14th days of the experiment. The other three groups were kept as control groups; non-immunized infected, non-immunized non-infected and adjuvant control. One week after the last booster dose, the lambs in all groups except control negative were challenged with 400 L3/kg live weight orally. Protein characterization of each antigen was done by SDS-PAGE and immunoblting. The vaccine efficacy was estimated by the fecal egg count, where the vaccinated groups showed 58.90% and 79.38% reduction in eggs in CAA and GST respectively. Moreover, 31.45% and 92.10% reduction in abomasal worm count was reported in CAA and GST vaccinated lambs, respectively. The protection was found corresponsive to the sera antibody levels in the immunized groups. It was concluded that the GST had protective efficacy against <i>H. contortus</i> infection in lambs.

In Vivo Nematicidal Potential of Camel Milk on Heligmosomoides Polygyrus Gastro-intestinal Nematode of Rodents.

SummaryFollowing our previous findings on the in vitro anthelmintic effect of camel milk on Haemonchus contortus, the current study aimed at investigating its in vivo effect. Investigations were carried out using mice infected with Heligmosomoides polygyrus which is a parasite commonly used to test the efficacy of anthelmintics. Thirty six Swiss white mice of both sexes aged 5 – 6 weeks old, and weighing between 20 and 25 g were orally infected with 0.5 ml dose of 100, 1-week-old H. polygyrus infective larvae (L3). After the pre-patent period, infected animals were randomly divided into 6 groups of 6 animals each. The nematicidal efficacy of camel milk was monitored through faecal egg count reduction (FECR) and total worm count reduction (TWCR). Four doses (8.25; 16.5; 33.0; 66.0 ml/kg body weight (bw)) for fresh camel milk and 22 mg/kg bw for albendazole were studied using a bioassay. Albendazole and 4 % dimethylsulfoxide were included in the protocol as reference drug and placebo, respectively. For all tested doses except 8.25 ml/kg bw, camel milk was effective in vivo against H. polygyrus reducing both faecal egg count and worm count (p < 0.05). The dose 66 ml/kg bw showed the highest nematicidal activity causing a 76.75 % FECR and a 69.62 % TWCR 7 day after initiating the treatment. These results support the possible use of camel milk in the control of gastro-intestinal helminthiasis.

In vitro and in vivo anthelmintic efficacy of two pentacyclic triterpenoids, ursolic acid and betulinic acid against mice pinworm, Syphacia obvelata.

Pinworm infections are one of the common problems in laboratory rodents and man. At present there are only few drugs against intestinal helminths, and new drugs are urgently needed to cope up any future risk of drug resistance. Interest in plant secondary metabolites (PSMs) has risen considerably in the recent years for the discovery and development of new drugs. In the present study, we explored the in vitro and in vivo anthelmintic potentials of two pentacyclic triterpenoids, ursolic acid (UA) and betulinic acid (BA), the important PSMs of many medicinal plants, against Syphacia obvelata (Nematoda: Oxyuridae), a common pinworm of mice. The results of this study indicated that in both, in vitro and in vivo assays, BA showed comparatively better anthelmintic effects than UA. In the in vitro assay, 1.00mg/ml concentration of BA showed paralysis and mortality of worms in 1.20±0.04 and 2.30±0.03h, respectively. In the in vivo assay, a single 10.00mg/kg dose of BA, administered for 5days, revealed 68.78% reduction in egg counts and 84.08% reduction in worm counts of infected mice. The present study suggests that BA holds a great promise to be pursued further for detailed testing against some other representative group of helminth parasites.

Immunoprotective Effect of Chitosan Particles on Hymenolepis nana - Infected Mice.

Hymenolepis nana is the most commonly known intestinal cestode infecting mainly human. This study aimed to investigate the potential effect of chitosan particles (CSP) to enhance the immune system against H.nana infection. Determination of worm burden, egg output, histopathological changes, oxidative stress markers (lipid peroxidation and reduced glutathione), goblet (GCs) and mucosal mast cells (MMCs) counts in intestinal ileum was performed. In addition, levels of intestinal mRNA expression of interleukin (IL)-4, IL-9, stem cell factor (SCF), type I and II interferons (IFN)-α/ γ, tumour necrosis factor (TNF)-α, mucin 2 (MUC2) and inducible nitric oxide synthase (iNOs) were investigated using real-time PCR. The results indicated induced reductions in adult worm and egg counts in infected mice after CSP treatment. This was associated with improvement in tissue morphometric measurements and oxidative stress which were altered after infection. Expression levels of iNOs, IFN-α, IFN-γ, TNF-α and IL-9 were decreased by CSP. Conversely, expression levels of MUC2, IL-4 and SCF increased compared to infected untreated group. In addition, GCs and MMCs counts were normalized by CSP. In conclusion, this study could indicate the immunoprotective effect of CSP against H.nana infection. This was characterized with Th2 anti-inflammatory responses.

Efficacy of a new spot-on formulation of selamectin plus sarolaner against Ancylostoma tubaeforme and Toxocara cati in cats

The efficacy of a new spot-on formulation of selamectin plus sarolaner for cats was evaluated against induced infections with Ancylostoma tubaeforme (hookworm) and Toxocara cati (roundworm). Five laboratory studies were conducted using adult, purpose-bred cats. Four of the studies were designed to evaluate efficacy of the combination against A. tubaeforme, the dose-limiting gastrointestinal nematode species for selamectin. In two of these studies non-interference between selamectin and sarolaner was also evaluated. The fifth study evaluated efficacy of the combination against mixed infections of A. tubaeforme and T. cati. The hookworm isolates in three studies were of US origin, as was the roundworm isolate. In the two remaining studies, cats were inoculated with a hookworm isolate of European origin. Cats were inoculated with 150 (±50) to 200 (±50) infective hookworm larvae 30–42days prior to treatment and with 400 infective roundworm eggs 60days prior to treatment. Cats were ranked by pre-treatment faecal egg counts and randomly allocated to different treatment groups. In all studies, cats were treated at the minimum label dose to provide 6.0mg selamectin per kg bodyweight. All animals were euthanized 7–10days after treatment for worm counts. Efficacy was calculated based on the reduction of the geometric mean worm counts in the treated groups versus the placebo-treated control groups.The efficacy against adult hookworms was 99.2%, 94.3% and 100% in three of these studies, and was lower in the remaining two studies. The efficacy against T. cati was 100%. Furthermore, non-interference between sarolaner and selamectin was demonstrated. Thus, a single topical application of the new spot-on formulation of selamectin plus sarolaner at the minimum label dose is effective in the treatment of adult hookworm and roundworm infections in cats.

Anthelmintic effects and toxicity of Cynodon dactylon (L.) Pers. in rodent models

Background: Cynodon dactylon (L.) Pers. is a very widely distributed medicinal herb. Different preparations from this herb are extensively used as a folk medicine in the Middle East, including Turkey, besides in India, Italy, etc. In India, the grinded juice of C. dactylon has been commonly used as a folk medicine for the treatment of intestinal-worm infections. Aim: This study was undertaken to investigate the in vitro and in vivo anthelmintic effects and potential toxicity of whole plant extract of C. dactylon against Hymenolepis diminuta (Hymenolepididae), a zoonotic tapeworm, using two rodent models. Materials and Methods: In in vitro assay, plant extract was tested at 10, 20 and 40 mg/ml concentrations, against adult H. diminuta, and the efficacy was adjudged by physical motility and mortality of parasites. In vivo testing was done in H. diminuta - Wistar rat model, by monitoring the eggs per gram of faeces (EPG) count and worm counts of animals after treatment with 200, 400, and 800 mg/kg doses of extract. Acute toxicity of extract was monitored with 2000 mg/kg oral dose of extract, following the OECD guidelines in Swiss albino mice. In sub-acute toxicity, a low extract dose, i.e. 400 mg/kg and a high extract dose, i.e. 800 mg/kg was tested in mice, as per the guidelines of OECD, for the assessment of some haematological and biochemical parameters of mice. Results: The extract showed a dose-dependent efficacy in both, the in vitro assay as well as in the in vivo assay. In the in vitro test, the 40 mg/ml concentration of extract caused paralysis and mortality of worms in as early as in 4.12 ± 0.55 h and 5.16 ± 0.34 h, respectively. This was comparable with the reference drug praziquantel (PZQ). The in vitro anthelmintic effects were also corroborated by the results of in vivo assay, wherein treatment of rats with 800 mg/kg dose of extract for 5 days revealed up to 77.64% reduction in EPG counts and 79.00% reduction in worm counts at post-treatment period, showing a comparable efficacy with 5 mg/kg dose treatment of PZQ. In the acute toxicity assay, the extract did not reveal any adverse effects or mortality in any animal, during the 14-days observation period. The LD50 of extract was estimated to be greater than 2000 mg/kg. In the sub-acute toxicity study, all the studied parameters of animals were found to be normal at 400 mg/kg dose (low dose), however, treatment with high dose, i.e., 800 mg/kg revealed only a slight elevation of aspartate aminotransferase (AST) in animals. Conclusion: C. dactylon possesses significant anthelmintic properties, and its extract appears to be devoid of any major adverse effects in experimental animals. These pharmacological credentials supports the safe folkloristic use of this plant as an anthelmintic remedy.

Immunization with Fasciola hepatica thioredoxin glutathione reductase failed to confer protection against fasciolosis in cattle

The liver fluke Fasciola hepatica remains an important agent of food-borne trematode disease producing great economic losses due to its negative effect on productivity of livestock grazing in temperate areas. The prevailing control strategy based on anthelmintic drugs is unsustainable due to widespread resistance hence vaccination appears as an attractive option to pursue. In this study we evaluate the effect of vaccination in calves with a functional recombinant thioredoxin glutathione reductase (rFhTGR) from liver fluke, a critical antioxidant enzyme at the crossroads of the thioredoxin and glutathione metabolism in flatworms. The recombinant enzyme produced in Escherichia coli was tested in two vaccination experiments; in the first trial rFhTGR was administered in combination with Freund́s Incomplete Adjuvant (FIA) in a three-inoculation scheme on weeks 0, 4 and 8; in the second trial rFhTGR was given mixed with Adyuvac 50 or Alum as adjuvants on weeks 0 and 4. In both cases calves were challenged with metacercariae (400 in the first and 500 in the second trial) 2 weeks after the last inoculation. Our results demonstrate that two or three doses of the vaccine induced a non-significant reduction in worm counts of 8.2% (FIA), 3.8% (Adyuvac 50) and 23.0% (Alum) compared to adjuvant controls indicating that rFhTGR failed to induce a protective immunity in challenged calves. All vaccine formulations induced a mixed IgG1/IgG2 response but no booster was observed after challenge. No correlations between antibody titres and worm burdens were found.

Anthelmintic activity of a standardized extract from the rhizomes of Acorus calamus Linn. (Acoraceae) against experimentally induced cestodiasis in rats.

Background:The rhizomes of a herb Acorus calamus Linn. (Acoraceae) have been widely used as a traditional medicine to cure intestinal-helminthic infections in India and South Africa.Aim:This study was undertaken to investigate the in vivo anthelmintic activity of a standardized methanolic extract obtained from the rhizomes A. calamus in a rodent model.Materials and Methods:A methanolic extract obtained from rhizomes of A. calamus was characterized for active principle using nuclear magnetic resonance 1H NMR, 13C NMR, mass and infrared spectroscopy. The amount of active principle in rhizome isolated active fraction of plant was assayed using high-performance liquid chromatography (HPLC). Later, the standardized rhizome extract of plant and its active principle were tested for in vivo anthelmintic efficacy against experimentally induced Hymenolepis diminuta, a zoonotic cestode, infections in rats.Results:The study revealed that b-asarone is the active principle of plant. The HPLC analysis of local variety of A. calamus revealed that active fraction contains 83.54% (w/w) of b-asarone. The in vivo study revealed that treatment of H. diminuta infected rats by a single 800 mg/kg dose of rhizome extract for 5 days results into 62.30% reduction in eggs per gram of feces counts and 83.25% reduction in worm counts of animals. These findings compared well with the efficacy of a reference drug, praziquantel. The active principle b-asarone showed slightly better anthelmintic effects than crude extract. In acute toxicity assay, a single oral 2000 mg/kg dose of extract did not reveal any signs of toxicity or mortality in mice, and the LD50 of the extract was noted to be >2000 mg/kg.Conclusion:Taken together, the results of this study indicate that rhizomes of A. calamus bear significant dose-dependent effects against intestinal helminths. Further, the Indian variety of A. calamus contains high b-asarone content. Therefore, there exists a great potential to develop some suitable anthelmintic herbal products from this plant.