Comparison of the toxic effects of two duncecap larkspur (Delphinium occidentale) chemotypes in mice and cattle
USDA Agricultural Research Service, Poisonous Plant Research Laboratory, 1150 E 1400 N, Logan, UT 84341, USA. American Journal of Veterinary Research
(Impact Factor: 1.34).
05/2011; 72(5):706-14. DOI: 10.2460/ajvr.72.5.706
To compare the toxic effects of a Delphinium occidentale chemotype containing N-(methylsuccinimido) anthranoyllycoctonine (MSAL)-type alkaloids and a D occidentale chemotype lacking MSAL-type alkaloids in mice and cattle.
225 male Swiss Webster mice and 11 Black Angus steers.
4 collections of larkspur containing MSAL-type alkaloids and 4 collections of larkspur lacking MSAL-type alkaloids were used. From each collection, total alkaloid extracts (0.05 to 0.20 mL) were administered via tail-vein injection in 27 to 29 mice. Dried, finely ground plant material from 1 collection with and 1 collection without MSAL-type alkaloids (doses equivalent to 37.6 mg of total alkaloids/kg) were each administered to 8 cattle via oral gavage in a crossover experiment; 3 cattle received a single dose equivalent to 150.4 mg of total alkaloids/kg (no MSAL-type alkaloids). In mice, clinical effects were monitored; in cattle, heart rate was monitored before (baseline) and 24 hours after treatment. At the 24-hour time point, cattle were exercised as a measure of muscle weakness.
In mice, mean LD(50) associated with alkaloid extracts prepared from plants that did or did not contain MSAL-type alkaloids was 2.3 and 54.2 mg/kg, respectively. In cattle at 24 hours after treatment, plant material containing MSAL-type alkaloids significantly increased heart rate from baseline and was associated with exercise-induced collapse; plant material lacking MSAL-type alkaloids had no similar effects.
Taxonomic classification of D occidentale alone was not a good indicator of the toxic risk to grazing cattle.
Available from: James A. Pfister
- "Research work using a mouse model suggested that MDL-type alkaloids enhance the overall acute toxicity of MLA in an additive manner . In subsequent studies with cattle, the MSAL-type alkaloids such as MLA were the primary factors responsible for the toxicity of larkspurs [16,21,22]. However, populations of larkspurs that contained large amounts of MDL-type alkaloids, in addition to high MSAL-type alkaloid content, were found to pose a greater risk to cattle than plants with only high MSAL-type alkaloids . "
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ABSTRACT: There are numerous species of larkspur (Delphinium spp.) in North America. Larkspurs are a major cause of cattle losses on western ranges in the USA, especially on foothill and mountain rangelands. The toxicity of larkspur species is due to various norditerpenoid alkaloids. In this article, we review the current knowledge regarding larkspur ecology and distribution, analytical technologies to study and quantify the toxins in larkspur, the toxicology of the larkspur plants and their individual toxins, known genetic variations in larkspur susceptibility, and current management recommendations to mitigate losses from larkspur poisoning.
Available from: Benedict T Green
- "provides minimal predictive value of D . stachydeum toxicity in cattle . Furthermore , D . occidentale from Logan , UT that contains only the non - MSAL - type alkaloids , when dosed at an equal dose to D . stachydeum ( 82 . 5 mg / kg ) or even dosed up to 150 . 4 mg total alkaloid / kg BW has elicited no clinical signs in previous dosing trials ( Cook et al . , 2011 ) . These data suggest that the response of cattle dosed with larkspur is not strictly due to the absence , or presence , of the MSAL - type alkaloids . Rather , it is the qualitative composition of the total alkaloids in a given species that determines how cattle may respond to a given larkspur species . Differences in toxicity between"
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ABSTRACT: Larkspurs (Delphinium spp.) are poisonous plants on rangelands throughout the Western United States and Canada. Larkspur-induced poisoning in cattle is due to norditerpene alkaloids that are represented by two main structural groups of norditerpene alkaloids, the N-(methylsuccinimido) anthranoyllycoctonine type (MSAL-type) and the non-MSAL type. Information on the alkaloid composition and resulting toxicity in mice and cattle is lacking for a number of Delphinium species, including D. stachydeum. The objective of this study was to determine the alkaloid composition of D. stachydeum and to characterize its relative toxicity in mice and cattle compared to two reference species D. barbeyi and D. occidentale. D. stachydeum contains the non-MSAL-type alkaloids but not the MSAL-type alkaloids. D. stachydeum was less toxic than D. barbeyi and D. occidentale in the mouse model. D. stachydeum was less toxic than the MSAL-containing D. barbeyi but much more toxic than the non-MSAL-containing D. occidentale in cattle as measured by heart rate and time of exercise. These results indicate that predictions of Delphinium toxicity can't be accurately made based solely on results from the mouse model or the absence of the MSAL-type alkaloids in the plant.
Copyright © 2015. Published by Elsevier Ltd.
Available from: M. Catherine Duryea
- "However, Pozo et al.  found that yeast growth was negatively affected by the alkaloids atropine and tropine found in the nectar of Atropa baetica. Given the well-known bioactivity of norditerpene alkaloids against vertebrate and invertebrate herbivores , , testing the effects of norditerpene alkaloids on nectar microbial communities warrants further investigation. "
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ABSTRACT: Microorganisms frequently colonize the nectar of angiosperm species. Though capable of altering a suite of traits important for pollinator attraction, few studies exist that test the degree to which they mediate pollinator foraging behavior. The objective of our study was to fill this gap by assessing the abundance and diversity of yeasts associated with the perennial larkspur Delphinium barbeyi (Ranunculaceae) and testing whether their presence affected components of pollinator foraging behavior. Yeasts frequently colonized D. barbeyi nectar, populating 54-77% of flowers examined depending on site. Though common, the yeast community was species-poor, represented by a single species, Metschnikowia reukaufii. Female-phase flowers of D. barbeyi were more likely to have higher densities of yeasts in comparison to male-phase flowers. Pollinators were likely vectors of yeasts, as virgin (unvisited) flowers rarely contained yeasts compared to flowers open to pollinator visitation, which were frequently colonized. Finally, pollinators responded positively to the presence of yeasts. Bombus foragers both visited and probed more flowers inoculated with yeasts in comparison to uninoculated controls. Taken together, our results suggest that variation in the occurrence and density of nectar-inhabiting yeasts have the potential to alter components of pollinator foraging behavior linked to pollen transfer and plant fitness.
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