Progress 09/20/06 to 02/10/08
Outputs
Progress Report Objectives (from AD-416) Develop immunologic diagnostic techniques to identify pyrrolizidine alkaloids (PA's) in feeds, foods, and animal tissues to identify poisoning, to characterize disease progression, and to prognose the fate of poisoned animals. PA and pyrrole conjugates will be tested as vaccines. Determine and describe the fetal and neonatal effects of other hepatotoxic and neurotoxic plants. Develop forage management and monitoring strategies to avoid poisoning and to assure feed and food quality. Approach (from AD-416) PA's and other plant alkaloids and metabolites will be conjugated to proteins and inoculated into animals. The resulting antibodies will be tested for specificity and developed into ELISA and immunohistochemical analytical methods. Immunized animals will be tested to determine if the resulting immunologic response alters PA toxicity. Chemical and immunologic techniques will be used to detect PA contaminates in feed and food, to diagnose intoxications and to monitor PA toxins and metabolites in vivo. PA toxicity in highly susceptible fetal and neonatal animals will be described. Toxicity and toxicokinetics information will be used to predict disease progression and better predict the risk of poisoning. The clinical, morphologic and molecular alterations in animals poisoned with other hepatotoxic and neurotoxic plants including rayless goldenrod (Happlopappus heterophyllus), and white snakeroot (Eupatoorium rugosum) will be described. Management and grazing strategies will be developed to provide quality livestock forage and ensure quality feeds and food. Significant Activities that Support Special Target Populations This research relates to NP 215 Rangeland, Pasture and Forage, Action Plan Component II, Subcomponent Rangeland Poisonous Plants, Problem Statement P. Hepatotoxic and neurotoxic plants, especially those containing pyrrolizidine alkaloids (PA�s) are found throughout the world and they often contaminate feed and food resulting in livestock and human poisoning. Sensitive assays to monitor feed and food for contamination and better descriptions of the mechanisms and conditions of poisoning are needed. Class and alkaloid specific ELISA�s have been developed and collaborative efforts expanded to make these assays available for screening foods and feed. PA-protein conjugates were evaluated as vaccines. Initial results showed little effect suggesting vaccination is not likely to be a useful tool to avoid poisoning. Additional studies of the effects of low dose PA exposure on susceptible neonatal and fetal animals have been initiated. As PA�s are carcinogenic, P53 knockout mice were obtained and pilot studies initiated to study the carcinogenicity of PA�s. Studies have also been initiated to develop a small animal model with altered PA metabolism and susceptibility. Descriptions of plant- induced poisoning by Adonis aestavalis (pheasant�s eye), Solanum triflorum (cutleaf nightshade), Panicum virgatum (switchgrass), Descurainia sophia (flixweed), and Cicuta maculate (water hemlock) in livestock were made, presented to user groups, and published. As rayless goldenrod (Haplopappus heterophyllus) and white snakeroot (Eupatorium rugosum) have historically been problematic for animal health and food safety, studies of fetal and neonatal toxicity to these plants have been started. ulk plant collections were made and mass spectrometry were developed to analyze plant material for tremetone, hydroxytremetone, dehydrotremetone and other tremetone like compounds. Facilities for large animal exercise, electromyography, and electrocardiographic monitoring were built and tested. Initial studies indicated rayless goldenrod is toxic for goats and horses. The information obtained from these pilot doses will be used to design subsequent dose response studies. As phylloerythrin is the cause of secondary photosensitization, monitoring its serum concentration is an excellent marker of hepatic function in herbivores. Continued progress was made in optimizing fluorescence spectrophotometry techniques for phylloerythrin detection. Quick and sensitive assays will facilitate screening feed and food for PA contamination to ensure product safety. Studies of low dose and chronic PA exposures will be used to better predict the risk of PA exposure to susceptible species and ages. The studies of additional hepatotoxic and neurotoxic plants will be used to promote control of these plant infestations and reduce animal exposures. Rayless goldenrod and white snake root studies will be useful to better understand these toxic plants and determining when they might be a risk to poison animals and contaminate feed, food, and animal products. Phylloerythrin assays will be useful in studying feed related animal photosensitivity. Technology Transfer Number of Web Sites managed: 1
Impacts
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Publications
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) Develop immunologic diagnostic techniques to identify pyrrolizidine alkaloids (PA's) in feeds, foods, and animal tissues to identify poisoning, to characterize disease progression, and to prognose the fate of poisoned animals. PA and pyrrole conjugates will be tested as vaccines. Determine and describe the fetal and neonatal effects of other hepatotoxic and neurotoxic plants. Develop forage management and monitoring strategies to avoid poisoning and to assure feed and food quality. Approach (from AD-416) PA's and other plant alkaloids and metabolites will be conjugated to proteins and inoculated into animals. The resulting antibodies will be tested for specificity and developed into ELISA and immunohistochemical analytical methods. Immunized animals will be tested to determine if the resulting immunologic response alters PA toxicity. Chemical and immunologic techniques will be used to detect PA contaminates in feed and food, to diagnose intoxications and to monitor PA toxins and metabolites in vivo. PA toxicity in highly susceptible fetal and neonatal animals will be described. Toxicity and toxicokinetics information will be used to predict disease progression and better predict the risk of poisoning. The clinical, morphologic and molecular alterations in animals poisoned with other hepatotoxic and neurotoxic plants including rayless goldenrod (Happlopappus heterophyllus), and white snakeroot (Eupatoorium rugosum) will be described. Management and grazing strategies will be developed to provide quality livestock forage and ensure quality feeds and food. Accomplishments PA vaccine studies: PA-protein conjugates, used as a vaccine, were immunized into rats that were later challenged with ridelliine. Vaccination had little effect on the clinical and histologic effects of toxicity. This suggests that vaccination under these conditions is not likely to be a useful tool in avoiding poisoning. Additional conjugates including conjugates with the pyrrole adduct are being developed. These are likely to be more effective as these are the toxic components of pyrrolizidine alkaloid poisoning. This information was presented and published in an international forum on toxic plants. Impact: Under these conditions vaccination does not appear to be a viable treatment for PA poisoning. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub- Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Pyrrolizidine alkaloid containing plant surveys: A relatively recent infestation of a plant commonly called �fireweed� (Senecio madagascariensis Poir.) among the Hawaii Islands has become a serious weed problem and heightened the concern for possible poisoning of grazing livestock in the area. Many of the Senecio spp. contain hepatotoxic pyrrolizidine alkaloids and if grazed over a period of time may induce irreversible liver damage. It is a major economic concern because of poisoning of cattle and horses. The plant is now very widespread in the area around Waimea (Kamuela) the primary cattle- ranching area of Hawaii. The potential for poisoning of livestock in this area is therefore extremely high. Samples of Senecio madagascariensis were collected from Australia, and from Hawaii, and the pyrrolizidine alkaloid content examined. Overall, no appreciable difference in alkaloid content was found between locations, whereas variation among individual plants was evident. The average total pyrrolizidine alkaloid content varied from 0.02 % to 0.20% (dry weight basis) among the locations. Based on comparable alkaloid content and documented pyrrolizidine alkaloidosis cases from Australia, S. madagascariensis may pose a significant risk to livestock grazing heavily infested ranges on the Hawaii islands. Impact: The risk and toxic potential of S. madagascariensis is better understood. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub-Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Photosensitization studies: Phylloerythrin is the cause of secondary photosensitization and it is an excellent marker of hepatic function in herbivores. Continued progress was made in optimizing fluorescence spectrophotometry techniques for phylloerythrin detection. Impact: Techniques for phylloerythrin detection were improved. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub-Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Adonis poisoning in cattle and horses: Field reports of Adonis aestavalis (pheasant�s eye) poisoning in cattle and horses were investigated and a rodent model used to verify poisoning. Syrian hamsters were dosed with ground Adonis at 0, 250 and 500 mg/kg BW. There was no effect at the 0 and low dose, however hamsters dosed with 500 mg/kg exhibited anorexia, diarrhea and became reluctant to move. Serum creatine phosphokinase activities were elevated which is consistent with mild myocardial damage. At necropsy the myocardial lesions were subtle with focal myocyte swelling. Ultrastructurally there were early lesions of myocardial mitochondrial swelling and myofiber disruption. The production of the classical cardioglycoside-associated myocardial lesions is variable and it is probably related to dose, duration, and recovery time. Based on these findings, Adonis aestavalis is cardiotoxic and contaminated hay should not be fed to livestock. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub-Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Cutleaf nightshade poisoning in horses: Cutleaf nightshade (Solanum triflorum) poisoning in horses was recently investigated and verified using a rodent model. The affected horses developed signs of cholinergic stimulation after they were observed eating the plant. They experienced severe salivation, frequent urination, diarrhea and colic. The poisoned horses recovered with no apparent permanent sequelae. Syrian hamsters were used to verify poisoning and to describe histologic changes. Hamsters were dosed at 0, 50, 100, 150 and 200 mg of ground plant. None of the hamsters developed cholinergic-like clinical signs as did the horses, however hamsters treated with the high dose developed diarrhea and small exterior labial-rectal lesions. Histologically these animals had focally extensive hemorrhagic and necrotizing gastroenteritis, most severe in the ileum. These findings suggest that the clinical and pathological effects of cutleaf nightshade poisoning manifest themselves in a different way in horses compared to hamsters. Therefore, additional studies need to be done for comparison. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub- Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Switchgrass toxicity in sheep, goats and horses: Switchgrass (Panicum virgatum) has been reported to cause a crystal- associated hepatic disease and photosensitivity similar to Kleingrass poisoning in livestock. Switchgrass hay was fed free choice to sheep, horses and goats for 90 days. Most of the animals lost body weight during the trial. None of the sheep or horses developed serum biochemical changes suggestive of hepatic or renal disease or damage. However, some of the goats fed switchgrass hay developed skin lesions consistent with phylloerythrin-associated photosensitivity and had hepatocellular swelling, hepatocyte necrosis and perinuclear cytoplasmic clearing sinusoids. These findings suggest that switchgrass may be toxic under certain conditions and young goats appear to be the most susceptible livestock species of the three tested. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub-Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Flixweed (Descurainia Sophia) toxicity in goats: A field case of flixweed toxicity in pregnant goats was investigated. A herd of 28 pregnant Boer goats fed grass hay containing 10-15% flixweed produced 59 kids, of which 41% were either born dead or died shortly after birth. Many of the affected kids were hairless with obvious thyroid hyperplasia (goiters) and had abnormally large birth weights. Glucosinolate analysis of the flixweed revealed significant levels of 3- butenyl (gluconapin) and allyl (sinigrin) glucosinolate. Subsequent removal of the flixweed from the goat�s diet and providing an iodine- containing mineral prevented further occurrence of goiter in this herd. Hay containing flixweed with significant quantities of glucosinolates should not be fed to pregnant animals. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub-Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Water hemlock poisoning in cattle: A case of apparent water hemlock poisoning in cattle was investigated. It has long been know that water hemlock tubers were extremely toxic to livestock. Field investigation determined that cattle placed in fresh pasture with a large population of water hemlock (Cicuta maculata) growing along the stream grazed water hemlock heavily. Nine cows died within 48 hours after introduction into the pasture. The water hemlock plants contained many green seed heads. Chemical analysis of green seeds revealed cicutoxin-like compounds in concentrations equal to the highly toxic tubers. Subsequent toxicology tests in a rodent model confirmed that the green seeds were equally toxic to the tubers. History, chemical analysis and follow up toxicology testing determined that water hemlock was the cause of toxicosis and death. Cows can be removed from a pasture and growing water hemlock to prevent further losses. NP Action Plan 108 Food Safety the Toxic Chemical Component, Sub-Component � Toxins in Range Plants and NP Action Plan 215 (205) Rangeland, Pasture, and Forages Problem Statement and Problem Area P � Rangeland Poisonous Plants. Technology Transfer Number of Web Sites managed: 1 Number of Non-Peer Reviewed Presentations and Proceedings: 6 Number of Newspaper Articles,Presentations for NonScience Audiences: 29
Impacts
(N/A)
Publications
- Panter, K.E., Gardner, D.R., Holstege, D., Stegelmeier, B.L. 2007. A case of acute water hemlock (cicuta maculata) poisoning and death in cattle after ingestion of green seed heads. Poisonous Plants Global Research and Solutions, Chpt. 44, pp. 259-264.
- Stegelmeier, B.L., Elmore, S.A., Lee, S.T., James, L.F., Gardner, D.R., Panter, K.E., Ralphs, M.H., Pfister, J.A. 2007. Switchgrass (panicum virgatum) toxicity in rodents, sheep, goats and horses. Poisonous Plants Global Research and Solutions, Chpt. 19,pp. 113 - 117.
- Stegelmeier, B.L., Hall, J.O., Lee, S.T., James, L.F., Gardner, D.R., Panter, K.E., Ralphs, M.H., Pfister, J.A. 2007. Pheasant's eye (adonis aestavalis) toxicity in livestock and rodents. Poisonous Plant Global Research and Solutions. Chpt. 79, pp. 463 - 468.
- Stegelmeier, B.L., Lee, S.T., James, L.F., Gardner, D.R., Panter, K.E., Ralphs, M.H., Pfister, J.A. 2007. Cutleaf nightshade (solanum triflorumm nutt.) toxicity in horses and hamsters. Poisonous Plant Global Research and Solutions, Chpt. 50, pp. 296 - 300.
- Stegelmeier, B.L., Lee, S.T., James, L.F., Gardner, D.R., Panter, K.E., Ralphs, M.H., Pfister, J.A. 2007. The effects of vaccination on riddelliine toxicity in rats. Poisonous Plant Global Research and Solutions, Chpt. 15, pp. 89 - 93.
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