title: Comparison of the toxic effects of two duncecap larkspur (Delphinium occidentale) chemotypes in mice and cattle.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  225 male Swiss Webster mice and 11 Black Angus steers.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Taxonomic classification of D occidentale alone was not a good indicator of the toxic risk to grazing cattle.
authors.affiliation: USDA Agricultural Research Service, Poisonous Plant Research Laboratory, 1150 E 1400 N, Logan, UT 84341, USA. Daniel.Cook@ars.usda.gov
authors.forename: Daniel
authors.initials: D
authors.lastname: Cook
authors.forename: Benedict T
authors.initials: BT
authors.lastname: Green
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Welch
authors.forename: Dale R
authors.initials: DR
authors.lastname: Gardner
authors.forename: James A
authors.initials: JA
authors.lastname: Pfister
authors.forename: Kip E
authors.initials: KE
authors.lastname: Panter
mesh_terms: D000470:Alkaloids / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D002417:Cattle; D018592:Cross-Over Studies; D031882:Delphinium / Q000737:chemistry / Q000145:classification / Q000633:toxicity*; D006339:Heart Rate / Q000187:drug effects*; D007928:Lethal Dose 50; D008297:Male; D051379:Mice; D053580:Muscle Strength / Q000187:drug effects*; D010805:Physical Conditioning, Animal; D010947:Plants, Toxic / Q000737:chemistry / Q000145:classification / Q000633:toxicity; D014481:United States
chemical_list: D000470:Alkaloids