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Harald Greger - One of the best experts on this subject based on the ideXlab platform.

  • Polyacetylenes from water hemlock, Cicuta virosa.
    Planta medica, 1995
    Co-Authors: Ute Wittstock, Franz Hadacek, Gerald Wurz, Eberhard Teuscher, Harald Greger
    Abstract:

    Isolation of polyacetylenes from aerial and subterranean parts of water hemlock, Cicuta virosa L. (Apiaceae. Apioideae), yielded eleven C 17 -polyacetylenes: cicutoxin (8a), cicutol (3a), (8E,10E)-heptadecadiene-4,6-diyne-1,12-diol (cicudiol, 7), 2,3-dihydrooenanthetol (1) and (8E)-heptadecene-4,6-diyne-1,10-diol (5b) already known to occur in water hemlock, the configurational isomers of cicutoxin (isocicutoxin, 8b) and of cicutol (isocicutol, 3b, and two incompletely characterised isomers with two cis-double bonds, 3c and 3d), all of them not described in previous investigations, falcarindiol (6), (1,8E,10E)-heptadecatriene-4,6-diyn-3-ol (2), already known from other Apiaceae, and the novel polyacetylene (1,8E/Z,10E,12E)-heptadecatetraene-4,6-diyn-3-ol (4a/b). Keto compounds, postulated to occur in water hemlock, could not be detected. HPLC profiles of the lipophilic extracts of different organs, individuals, and provenances of water helmock harvested at different seasons revealed quantitative but not qualitative variations of the polyacetylene composition.

Ute Wittstock - One of the best experts on this subject based on the ideXlab platform.

  • CICUTOXIN FROM Cicuta VIROSA : A NEW AND POTENT POTASSIUM CHANNEL BLOCKER IN T LYMPHOCYTES
    Biochemical and biophysical research communications, 1996
    Co-Authors: Ulf Strauß, Ute Wittstock, Eberhard Teuscher, Rudolf Schubert, Stefan Jung, Eilhard Mix
    Abstract:

    Abstract The effect of cicutoxin, the poisonous principle of the genus Cicuta , on K + currents of activated T lymphocytes was investigated using the patch clamp technique. Cicutoxin produced a dose-dependent [5 × 10 − 6 –7 × 10 −5 mol/l] and completely reversible block of K + currents with an EC 50 of 1.8 × 10 −5 mol/l. A maximum block of 71% was achieved with cicutoxin at a concentration of 7 × 10 −5 mol/l. Since previous studies have shown that T lymphocyte proliferation is associated with K + currents, the effect of cicutoxin on T lymphocyte proliferation was studied by means of 3 H-thymidine uptake assays. At noncytotoxic concentrations [10 −7 −5 × 10 −5 mol/l] cicutoxin reduced the 3 H-thymidine incorporation dose-dependently. In conclusion, cicutoxin is a potent K + current blocker which inhibits K + channel-dependent proliferation of naive and memory T lymphocytes.

  • Polyacetylenes from water hemlock, Cicuta virosa.
    Planta medica, 1995
    Co-Authors: Ute Wittstock, Franz Hadacek, Gerald Wurz, Eberhard Teuscher, Harald Greger
    Abstract:

    Isolation of polyacetylenes from aerial and subterranean parts of water hemlock, Cicuta virosa L. (Apiaceae. Apioideae), yielded eleven C 17 -polyacetylenes: cicutoxin (8a), cicutol (3a), (8E,10E)-heptadecadiene-4,6-diyne-1,12-diol (cicudiol, 7), 2,3-dihydrooenanthetol (1) and (8E)-heptadecene-4,6-diyne-1,10-diol (5b) already known to occur in water hemlock, the configurational isomers of cicutoxin (isocicutoxin, 8b) and of cicutol (isocicutol, 3b, and two incompletely characterised isomers with two cis-double bonds, 3c and 3d), all of them not described in previous investigations, falcarindiol (6), (1,8E,10E)-heptadecatriene-4,6-diyn-3-ol (2), already known from other Apiaceae, and the novel polyacetylene (1,8E/Z,10E,12E)-heptadecatetraene-4,6-diyn-3-ol (4a/b). Keto compounds, postulated to occur in water hemlock, could not be detected. HPLC profiles of the lipophilic extracts of different organs, individuals, and provenances of water helmock harvested at different seasons revealed quantitative but not qualitative variations of the polyacetylene composition.

Eberhard Teuscher - One of the best experts on this subject based on the ideXlab platform.

  • CICUTOXIN FROM Cicuta VIROSA : A NEW AND POTENT POTASSIUM CHANNEL BLOCKER IN T LYMPHOCYTES
    Biochemical and biophysical research communications, 1996
    Co-Authors: Ulf Strauß, Ute Wittstock, Eberhard Teuscher, Rudolf Schubert, Stefan Jung, Eilhard Mix
    Abstract:

    Abstract The effect of cicutoxin, the poisonous principle of the genus Cicuta , on K + currents of activated T lymphocytes was investigated using the patch clamp technique. Cicutoxin produced a dose-dependent [5 × 10 − 6 –7 × 10 −5 mol/l] and completely reversible block of K + currents with an EC 50 of 1.8 × 10 −5 mol/l. A maximum block of 71% was achieved with cicutoxin at a concentration of 7 × 10 −5 mol/l. Since previous studies have shown that T lymphocyte proliferation is associated with K + currents, the effect of cicutoxin on T lymphocyte proliferation was studied by means of 3 H-thymidine uptake assays. At noncytotoxic concentrations [10 −7 −5 × 10 −5 mol/l] cicutoxin reduced the 3 H-thymidine incorporation dose-dependently. In conclusion, cicutoxin is a potent K + current blocker which inhibits K + channel-dependent proliferation of naive and memory T lymphocytes.

  • Polyacetylenes from water hemlock, Cicuta virosa.
    Planta medica, 1995
    Co-Authors: Ute Wittstock, Franz Hadacek, Gerald Wurz, Eberhard Teuscher, Harald Greger
    Abstract:

    Isolation of polyacetylenes from aerial and subterranean parts of water hemlock, Cicuta virosa L. (Apiaceae. Apioideae), yielded eleven C 17 -polyacetylenes: cicutoxin (8a), cicutol (3a), (8E,10E)-heptadecadiene-4,6-diyne-1,12-diol (cicudiol, 7), 2,3-dihydrooenanthetol (1) and (8E)-heptadecene-4,6-diyne-1,10-diol (5b) already known to occur in water hemlock, the configurational isomers of cicutoxin (isocicutoxin, 8b) and of cicutol (isocicutol, 3b, and two incompletely characterised isomers with two cis-double bonds, 3c and 3d), all of them not described in previous investigations, falcarindiol (6), (1,8E,10E)-heptadecatriene-4,6-diyn-3-ol (2), already known from other Apiaceae, and the novel polyacetylene (1,8E/Z,10E,12E)-heptadecatetraene-4,6-diyn-3-ol (4a/b). Keto compounds, postulated to occur in water hemlock, could not be detected. HPLC profiles of the lipophilic extracts of different organs, individuals, and provenances of water helmock harvested at different seasons revealed quantitative but not qualitative variations of the polyacetylene composition.

James R. Manhart - One of the best experts on this subject based on the ideXlab platform.

Kevin D. Welch - One of the best experts on this subject based on the ideXlab platform.

  • The acute toxicity of water hemlock (Cicuta douglasii) in a goat model.
    Toxicon : official journal of the International Society on Toxinology, 2020
    Co-Authors: Kevin D. Welch, Clinton A. Stonecipher, Stephen T. Lee, Daniel Cook
    Abstract:

    Abstract Water hemlock (Cicuta douglasii) is one of the most toxic plants to livestock and humans. Little is known regarding the amount of plant required to cause death. The objective of this study was to determine a lethal dose of water hemlock in a goat model. Plants were dosed to goats via oral gavage of freeze-dried ground plant material. The results from this study suggest that 1–2 fresh tubers would be lethal to goats.

  • Geographical and seasonal variation in water hemlock (Cicuta maculata) toxins
    Biochemical Systematics and Ecology, 2020
    Co-Authors: Clinton A. Stonecipher, Kevin D. Welch, Stephen T. Lee, Daniel Cook, James A. Pfister
    Abstract:

    Abstract Water hemlock (Cicuta spp.) plants are typically found in wet areas and are toxic to all species of livestock. The toxic components in water hemlock are C17 polyacetylenes, with cicutoxin being the most studied. The objective of this study was to evaluate the variation in cicutoxin and total C17 polyacetylene compounds in water hemlock populations across western North America. Cicutoxin and total C17 polyacetylene concentrations varied among the six collection locations and among plant parts. Tubers contained the highest cicutoxin and total C17 polyacetylene concentrations of all plant parts. Green seeds contained the second most abundant total C17 polyacetylene concentrations. Total C17 polyacetylene and cicutoxin concentrations were also compared in different plant parts at several different phenological stages over the growing season. Cicutoxin and total C17 polyacetylene concentrations in the tubers increased until the green seed stage whereupon the concentrations decreased as the seeds matured and the plant began to senesce. Concentrations of secondary compounds in the stems were consistent with the optimal defense theory in which secondary compounds were higher in stems in earlier development stages compared to later stages and concentrations in seeds were higher than other above ground parts. The toxic compounds are found in all plant parts, with tubers posing the most significant risk of livestock poisoning. Results presented in this study suggest that the toxic risk to livestock likely does not differ between water hemlock (Cicuta maculata) populations across western North America under similar circumstances of ingestion.

  • The non-competitive blockade of GABAA receptors by an aqueous extract of water hemlock (Cicuta douglasii) tubers.
    Toxicon : official journal of the International Society on Toxinology, 2015
    Co-Authors: Benedict T. Green, Camila França De Paula Orlando Goulart, Kevin D. Welch, James A. Pfister, Isabelle Mccollum, Dale R. Gardner
    Abstract:

    Water hemlocks (Cicuta spp.) are acutely toxic members of the Umbellierae family; the toxicity is due to the presence of C17-polyacetylenes such as cicutoxin. There is only limited evidence of noncompetitive antagonism by C17-polyacetylenes at GABAA receptors. In this work with WSS-1 cells, we documented the noncompetitive blockade of GABAA receptors by an aqueous extract of water hemlock (Cicuta douglasii) and modulated the actions of the extract with a pretreatment of 10 μM midazolam.

  • Water hemlock poisoning in cattle: Ingestion of immature Cicuta maculata seed as the probable cause
    Toxicon : official journal of the International Society on Toxinology, 2010
    Co-Authors: Kip E. Panter, Kevin D. Welch, Dale R. Gardner, Bryan L. Stegelmeier, Dirk M. Holstege
    Abstract:

    It is well understood that water hemlock tubers are highly toxic to animals and to humans. However, this is the first time that immature seed from (Cicuta maculata) has been implicated in livestock poisoning. Nine mature Hereford cows from a herd of 81 died in northwestern Utah after ingesting immature seed heads of water hemlock (Cicuta maculata) in late summer. No obvious signs of poisoning were reported as all nine were found dead near the banks of the stream where water hemlock was found. Upon discovery of the dead cows, the remaining 72 cows were immediately removed from the pasture and no further losses occurred. Field necropsy of 3 of the dead cows and follow-up serology and histopathological examination of selected tissues did not identify any bacterial or viral causes. History of ingestion of large quantities of water hemlock seed, the acute nature of the deaths, chemical comparison of seed with toxic tubers and follow-up mouse bioassay testing supported the diagnosis of water hemlock poisoning. Seed heads collected from the neighboring pasture upstream and across the fence from the poisoned cattle and tubers collected from grazed plants were chemically analyzed and found to contain cicutoxin, and high levels of two cicutol-like derivatives (cicutol-#1 and #2) as well as other unidentified polyacetylene compounds. Seeds and tubers from suspected plants were semi-quantified and compared to archive samples of highly toxic tubers used in previous experiments. The immature hemlock seed contained less cicutoxin (0.01 times), but 9.5 and 22.5 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Tubers from the grazed plants contained 4.6 times more cicutoxin and 9.8 and 18.8 times more cicutol-#1 and cicutol-#2 respectively, compared to the archive sample. Mouse bioassays with water extracts of immature seed and tubers from grazed plants demonstrated both were highly toxic and of greater toxicity when compared to archived sample.