The Experts below are selected from a list of 66 Experts worldwide ranked by ideXlab platform
P Hordegen - One of the best experts on this subject based on the ideXlab platform.
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In vitro screening of six anthelmintic plant products against larval Haemonchus contortus with a modified methyl-thiazolyl-tetrazolium reduction assay
Journal of Ethnopharmacology, 2006Co-Authors: P Hordegen, Jacques Cabaret, H Hertzberg, W Langhans, V MaurerAbstract:Because of the increasing anthelmintic resistance and the impact of conventional anthelmintics on the environment, it is important to look for alternative strategies against gastrointestinal nematodes. Phytotherapy could be one of the major options to control these pathologies. Extracts or ingredients of six different plant species were tested against exsheathed infective larvae of Haemonchus contortus using a modified methyl-thiazolyl-tetrazolium (MTT) reduction assay. Pyrantel Tartrate was used as reference anthelmintic. Bromelain, the enzyme complex of the stem of Ananas comosus (Bromeliaceae), the ethanolic extracts of seeds of Azadirachta indica (Meliaceae), Caesalpinia crista (Caesalpiniaceae) and Vernonia anthelmintica (Asteraceae), and the ethanolic extracts of the whole plant of Fumaria parviflora (Papaveraceae) and of the fruit of Embelia ribes (Myrsinaceae) showed an anthelmintic efficacy of up to 93%, relative to Pyrantel Tartrate. Based on these results obtained with larval Haemonchus contortus, the modified MTT reduction assay could be a possible method for testing plant products with anthelmintic properties.
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the anthelmintic efficacy of five plant products against gastrointestinal trichostrongylids in artificially infected lambs
Veterinary Parasitology, 2003Co-Authors: P Hordegen, W Langhans, Hubertus Hertzberg, Jorg Heilmann, Veronika MaurerAbstract:Forty-eight helminth-free lambs were divided into eight groups (A-H) of six animals. Groups A-G were infected artificially with 10,000 third stage larvae of Haemonchus contortus and 20,000 third stage larvae of Trichostrongylus colubriformis, whereas group H remained uninfected. Thirty days post-infection the lambs were treated orally with a single dosage of one of the following products: group A with 3 mg/kg body weight (BW) of an aqueous ethanol extract (70%, v/v) of the seeds of Azadirachta indica A. Juss syn. Melia azedarach L. (Meliaceae); group B with 1 g/kg BW of a raw powder of the leaves of Ananas comosus (L.) Merr. (Bromeliaceae); group C with 0.3 mg/kg BW of an aqueous ethanol extract of a 1:1 mixture (g/g) of Vernonia anthelmintica (L.) Willd. (Asteraceae) seeds and Embelia ribes Burm (Myrsinaceae) fruits; group D with 183 mg/kg BW of an aqueous ethanol extract of the whole plants of Fumaria parviflora Lam. (Fumariaceae); group E with 28 mg/kg BW of an aqueous ethanol extract of the seeds of Caesalpinia crista L. (Caesalpiniaceae); group F with 25 mg/kg BW of Pyrantel Tartrate and group G with 50% ethanol. Group H remained untreated. Only the ethanol extract of F. parviflora caused a strong reduction of the faecal egg counts (100%) and a 78.2 and 88.8% reduction of adult H. contortus and T. colubriformis on day 13 post-treatment. The extract was as effective as the reference compound Pyrantel Tartrate. Therefore, the ethanol extract itself or single constituents of F. parviflora could be a promising alternative source of anthelmintic for the treatment of gastrointestinal trichostrongylids in small ruminants.
T. R. Klei - One of the best experts on this subject based on the ideXlab platform.
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experimental cyathostome challenge of ponies maintained with or without benefit of daily Pyrantel Tartrate feed additive comparison of parasite burdens immunity and colonic pathology
Veterinary Parasitology, 1998Co-Authors: C.m. Monahan, T. R. Klei, H.w. Taylor, D D French, M R ChapmanAbstract:Abstract Eighteen mixed-breed, naturally infected ponies ranging in age from 1 to 16 yr and four cyathostome-naive ponies reared and maintained under parasite-free conditions ranging in age from 1 to 4 yr were used in this study. Naturally-infected ponies were treated with 1 dose of ivermectin (IVM) at 200 μg kg−1, followed by a 5-day regimen of oxibendazole (OBZ) at 20 mg kg−1 to remove existing cyathostome burdens; cyathostome-naive control ponies were treated with IVM alone. The naturally infected ponies were matched on age and gender, then randomly assigned to one of three treatment groups of six animals per group; the four cyathostome-naive ponies constituted a fourth group. Following OBZ treatment, Group 1 ponies were treated with Pyrantel Tartrate (PT) in their pelleted ration; the remaining ponies received only the pelleted ration. Beginning on experiment Day 3, a daily challenge infection of 104 mixed cyathostome larvae was administered orally to ponies of Group 1, Group 2 and the cyathostome-naive controls. Group 3 ponies served as unchallenged controls to determine residual parasite burdens following IVM/OBZ treatment. Necropsy examinations were performed on three Group 3 ponies on Day 1; the remainder of the necropsy examinations began on Day 41. Cyathostome burdens were evaluated by recovery of larvae and adults from the luminal contents, by digestions of the intestinal mucosa, and by mural transillumination of full-thickness intestinal sections. Differences in postchallenge clinical responses were also compared. Necropsy examinations included comparisons of grossly visible inflammation of the large bowel, weights of biopsy specimens from each region, and histologic evaluations of these biopsies. Parasite recoveries at necropsy indicated a strong protective effect derived from daily PT treatment. Mean weights of intestinal biopsies corresponded with worm burdens, but histological evaluation did not reveal architectural or cellular changes to account for the increase in weight; therefore, edema was suspected. A strong age-related resistance to challenge infection was apparent in both the PT-treated and control groups by virtue of the lower mean worm burdens found in older ponies compared to younger ponies of the same treatment group; however, daily PT treatment of older ponies reduced the variability of their worm burdens to a uniformly low level. Comparisons of luminal and mucosal parasite burdens of age stratified nontreated controls further suggest that the age related resistance, which is acquired, targets increasing numbers of parasite stages as this resistance matures. Further, there is no evidence for an immune mediated acquisition of hypobiotic L3.
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Foals raised on pasture with or without daily Pyrantel Tartrate feed additive: comparison of parasite burdens and host responses following experimental challenge with large and small strongyle larvae.
Veterinary parasitology, 1997Co-Authors: C.m. Monahan, H.w. Taylor, D D French, T. R. KleiAbstract:Three groups of foals were raised under different management programs in this study: Group 1 (n = 6) and Group 2 (n = 6) were raised with their dams on pasture; Group 3 foals (n = 5) were raised under parasite-free conditions. Mares and foals of Group 1 received daily Pyrantel Tartrate (PT) treatment with their pelleted feed ration, whereas mares and foals of Groups 2 and 3 received only the pelleted ration. Pasture-reared foals were weaned and moved to a heavily contaminated pasture for 5 weeks. Group 1 foals continued to receive daily PT treatment whereas Group 2 foals received only the pelleted feed ration. Following this period, all foals were moved into box stalls. Half of each group was challenged with 10(3) Strongylus vulgaris infective third-stage larvae (L3), 5 x 10(3) Strongylus edentatus L3 and 10(5) mixed cyathostome L3; the remaining half served as unchallenged controls. Necropsy examinations were performed 6-week post-challenge for evaluation of parasite burdens and lesions. Daily PT treatment of Group 1 reduced the patent cyathostome infections of both mares and foals and was effective in reducing pasture burdens of infective larvae. Daily treatment of Group 1 foals during weaning continued to suppress EPG levels; however, it did not prevent large strongyle infections during the weaning period. Group 1 foals were more sensitive to challenge than Group 2 foals, which did not exhibit any post-challenge disturbances. Group 1 foals were equally susceptible to challenge as parasite-free foals.
V Maurer - One of the best experts on this subject based on the ideXlab platform.
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In vitro screening of six anthelmintic plant products against larval Haemonchus contortus with a modified methyl-thiazolyl-tetrazolium reduction assay
Journal of Ethnopharmacology, 2006Co-Authors: P Hordegen, Jacques Cabaret, H Hertzberg, W Langhans, V MaurerAbstract:Because of the increasing anthelmintic resistance and the impact of conventional anthelmintics on the environment, it is important to look for alternative strategies against gastrointestinal nematodes. Phytotherapy could be one of the major options to control these pathologies. Extracts or ingredients of six different plant species were tested against exsheathed infective larvae of Haemonchus contortus using a modified methyl-thiazolyl-tetrazolium (MTT) reduction assay. Pyrantel Tartrate was used as reference anthelmintic. Bromelain, the enzyme complex of the stem of Ananas comosus (Bromeliaceae), the ethanolic extracts of seeds of Azadirachta indica (Meliaceae), Caesalpinia crista (Caesalpiniaceae) and Vernonia anthelmintica (Asteraceae), and the ethanolic extracts of the whole plant of Fumaria parviflora (Papaveraceae) and of the fruit of Embelia ribes (Myrsinaceae) showed an anthelmintic efficacy of up to 93%, relative to Pyrantel Tartrate. Based on these results obtained with larval Haemonchus contortus, the modified MTT reduction assay could be a possible method for testing plant products with anthelmintic properties.
W Langhans - One of the best experts on this subject based on the ideXlab platform.
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In vitro screening of six anthelmintic plant products against larval Haemonchus contortus with a modified methyl-thiazolyl-tetrazolium reduction assay
Journal of Ethnopharmacology, 2006Co-Authors: P Hordegen, Jacques Cabaret, H Hertzberg, W Langhans, V MaurerAbstract:Because of the increasing anthelmintic resistance and the impact of conventional anthelmintics on the environment, it is important to look for alternative strategies against gastrointestinal nematodes. Phytotherapy could be one of the major options to control these pathologies. Extracts or ingredients of six different plant species were tested against exsheathed infective larvae of Haemonchus contortus using a modified methyl-thiazolyl-tetrazolium (MTT) reduction assay. Pyrantel Tartrate was used as reference anthelmintic. Bromelain, the enzyme complex of the stem of Ananas comosus (Bromeliaceae), the ethanolic extracts of seeds of Azadirachta indica (Meliaceae), Caesalpinia crista (Caesalpiniaceae) and Vernonia anthelmintica (Asteraceae), and the ethanolic extracts of the whole plant of Fumaria parviflora (Papaveraceae) and of the fruit of Embelia ribes (Myrsinaceae) showed an anthelmintic efficacy of up to 93%, relative to Pyrantel Tartrate. Based on these results obtained with larval Haemonchus contortus, the modified MTT reduction assay could be a possible method for testing plant products with anthelmintic properties.
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the anthelmintic efficacy of five plant products against gastrointestinal trichostrongylids in artificially infected lambs
Veterinary Parasitology, 2003Co-Authors: P Hordegen, W Langhans, Hubertus Hertzberg, Jorg Heilmann, Veronika MaurerAbstract:Forty-eight helminth-free lambs were divided into eight groups (A-H) of six animals. Groups A-G were infected artificially with 10,000 third stage larvae of Haemonchus contortus and 20,000 third stage larvae of Trichostrongylus colubriformis, whereas group H remained uninfected. Thirty days post-infection the lambs were treated orally with a single dosage of one of the following products: group A with 3 mg/kg body weight (BW) of an aqueous ethanol extract (70%, v/v) of the seeds of Azadirachta indica A. Juss syn. Melia azedarach L. (Meliaceae); group B with 1 g/kg BW of a raw powder of the leaves of Ananas comosus (L.) Merr. (Bromeliaceae); group C with 0.3 mg/kg BW of an aqueous ethanol extract of a 1:1 mixture (g/g) of Vernonia anthelmintica (L.) Willd. (Asteraceae) seeds and Embelia ribes Burm (Myrsinaceae) fruits; group D with 183 mg/kg BW of an aqueous ethanol extract of the whole plants of Fumaria parviflora Lam. (Fumariaceae); group E with 28 mg/kg BW of an aqueous ethanol extract of the seeds of Caesalpinia crista L. (Caesalpiniaceae); group F with 25 mg/kg BW of Pyrantel Tartrate and group G with 50% ethanol. Group H remained untreated. Only the ethanol extract of F. parviflora caused a strong reduction of the faecal egg counts (100%) and a 78.2 and 88.8% reduction of adult H. contortus and T. colubriformis on day 13 post-treatment. The extract was as effective as the reference compound Pyrantel Tartrate. Therefore, the ethanol extract itself or single constituents of F. parviflora could be a promising alternative source of anthelmintic for the treatment of gastrointestinal trichostrongylids in small ruminants.
Craig R. Reinemeyer - One of the best experts on this subject based on the ideXlab platform.
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Serum Strongylus vulgaris-specific antibody responses to anthelmintic treatment in naturally infected horses
Parasitology Research, 2015Co-Authors: Martin K. Nielsen, Holli S Gravatte, Anand N. Vidyashankar, Jennifer Bellaw, Xin Cao, Emily F. Rubinson, Craig R. ReinemeyerAbstract:Strongylus vulgaris is the most pathogenic helminth parasite of horses, causing verminous endarteritis with thromboembolism and infarction. A serum enzyme-linked immunosorbent assay (ELISA) has been validated for detection of antibodies to an antigen produced by migrating larvae of this parasite. The aim was to evaluate ELISA responses to anthelmintic treatment in cohorts of naturally infected horses. Fifteen healthy horses harboring patent S. vulgaris infections were turned out for communal grazing in May 2013 (day 0). On day 55, horses were ranked according to ELISA titers and randomly allocated to the following three groups: no treatment followed by placebo pellets daily; ivermectin on day 60 followed by placebo pellets daily; or ivermectin on day 60 followed by daily Pyrantel Tartrate. Fecal and serum samples were collected at ∼28-day intervals until study termination on day 231. Increased ELISA values were observed for the first 53 days following ivermectin treatment. Titers were significantly reduced 80 days after ivermectin treatment. Horses receiving daily Pyrantel Tartrate maintained lower ELISA values from 137 days post ivermectin treatment until trial termination. These results illustrate that a positive ELISA result is indicative of either current or prior exposure to larval S. vulgaris infection within the previous 5 months.
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effects of daily Pyrantel Tartrate on strongylid population dynamics and performance parameters of young horses repeatedly infected with cyathostomins and strongylus vulgaris
Veterinary Parasitology, 2014Co-Authors: Craig R. Reinemeyer, M K Nielsen, U V Andersen, Julio C Prado, B Schricker, T KennedyAbstract:Strongylid infections are ubiquitous in grazing horse populations. Infections with cyathostomin (small strongyle) and strongylin (large strongyle) nematodes have long been associated with clinical disease in horses, but little is known about their subclinical impact. A masked, randomized, controlled study was conducted to evaluate the effects of daily administration of Pyrantel Tartrate on body condition scores, weight gain, fecal egg counts, and total worm counts of young horses repeatedly inoculated with strongylid larvae. Twenty eight immature horses were treated with larvicidal anthelmintic regimens and randomly allocated to two groups. Group 1 horses were given a pelleted placebo product once daily, and those in Group 2 received Pyrantel Tartrate once daily at ∼ 2.64 mg/kg body weight. On five days during each week, ∼ 5000 infective cyathostomin larvae were administered to each horse. In addition, horses received ∼ 25 infective Strongylus vulgaris larvae once weekly. Horses were maintained on pasture for 154 days and had ad libitum access to grass hay throughout. At approximate, 14-day intervals, body weights were measured, body condition scores were assigned, fecal samples were collected for egg counts, and blood samples were collected for measurement of S. vulgaris antibodies and various physiologic parameters. After 22 weeks at pasture and 14-17 days in confinement, horses were euthanatized and necropsied. Nematodes were recovered and counted from aliquots of organ contents, representative samples of large intestinal mucosa, and the root of the cranial mesenteric artery. Daily treatment with Pyrantel Tartrate at the recommended dosage significantly reduced numbers of adult cyathostomins in the gut lumen and early third-stage larvae in the cecal mucosa, increased the proportions of fourth-stage larvae in the gut contents, and was accompanied by significant improvements in body condition scores. Fecal egg counts of horses receiving daily Pyrantel Tartrate were significantly reduced, with percentages of efficacy ranging from 84.4% to 98.9%, but egg counts of both groups increased significantly over the course of the study. Treatment also significantly reduced the numbers of S. vulgaris larvae in the cranial mesenteric artery by 99.2%. Serum antibodies to S. vulgaris apparently persisted from pre-enrollment infections, but ELISA values gradually declined over the course of the study. This study has provided useful insights into the effects of daily Pyrantel Tartrate on the dynamics of cyathostomin infection, and into some subclinical effects of strongylid parasitism in horses.
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physiologic and systemic acute phase inflammatory responses in young horses repeatedly infected with cyathostomins and strongylus vulgaris
Veterinary Parasitology, 2014Co-Authors: U V Andersen, Stine Jacobsen, S.n. Olsen, Craig R. Reinemeyer, Nils Toft, M K NielsenAbstract:Abstract Migrating Strongylus vulgaris and encysted cyathostomin larvae cause a localized inflammatory response in horses. It is unknown whether these larvae elicit a systemic acute phase response (APR), evidenced by changes in serum amyloid A (SAA), haptoglobin (Hp), iron (Fe), albumin, or albumin/globulin (A/G) ratio. In this study, 28 horses were randomly allocated to receive either Pyrantel Tartrate or a pelleted placebo formulation in their daily feed. Concurrent with treatment, all the horses were administered 5000 Pyrantel-susceptible cyathostomin infective larvae once daily, 5 days a week, for 24 weeks. Beginning in the fifth week, the horses also received 25 S. vulgaris larvae once weekly for the remainder of the study. At regular biweekly intervals, fecal samples were collected for quantitative egg counts, and whole blood and serum samples were collected for measurement of packed cell volume, total protein, albumin, globulin, A/G ratio, SAA, Hp, and Fe. On days 161–164, all the horses were euthanatized and necropsied. Samples were collected for enumeration of total luminal worm burdens, encysted cyathostomin larval populations, and migrating S. vulgaris larvae. Concentrations of Hp, Fe, and A/G ratio were associated significantly with strongyle burdens. Only treated male horses had significant increases in serum albumin. Larval S. vulgaris did not associate with Fe, whereas Fe was associated negatively with both total cyathostomin burdens and encysted L4s. The A/G ratios differed significantly between the two treatment groups. Significant differences between groups and individual time points were also observed for Hp and Fe, whereas SAA concentrations remained low throughout the study. In general, this study illustrated that experimental inoculations with S. vulgaris and cyathostomins may be associated with changes in Hp, Fe, and serum proteins, but not with SAA. Overall, these changes suggest that mixed strongyle infections elicit a mild acute phase reaction.
