VET406- Plant toxins CONDENSED

Lectures 8/23/24

Piperdine alkaloids

• Affects which system

• Plants

• Mechanism or effect

“Piper the Wolf smoked tobacco by the hemlock tree” 

• Nervous system

• Lupine, tobacco, poison hemlock

• Targets Ach 

Cyanogenic glycosides

• Affects which system

• Plants

• Mechanism or effect

“Cyan choked on Arrows and Gum inside the Toy box”

• Nervous system

• choke cherries, Arrow grass, sorghum, toyon

• beta-glucosidase yields hydrogen cyanide

  • Tx: sodium nitrate, sodium thiosulfate

Unknown toxin - chewing disease

• Affects which system

• Plants

• Mechanism or effect

“Russians chew on yellow stars” 

• Nervous system

• Russian knapweed, Yellow Star thistle 

• Chewing disease- specific to horses 

Cardiac glycosides

• Affects which system

• Plants

• Mechanism or effect 

“ Ole! my cardio is great!”

• Cardiovascular system 

• Oleander

• increase HR

Grayanotoxins

• Affects which system

• Plants

• Mechanism or effect

“Gray rhodes drove his azalea up the mountain to Laurel” 

• Cardiovascular

• Rhododendron, Azalea, Mountain Laurel

• increase HR

Taxine Alkaloids

• Affects which system

• Plants

• Mechanism or effect

“Don’t let the taxes hurt yew!”

• Cardiovascular 

• Yews

• fetal conduction disturbance in the heart 

Persin

• Affects which system

• Plants

• Mechanism or effect

• Cardiovascular

• Avocado

• —

Toxalbumins/ Lectins

• Affects which system

• Plants

• Mechanism or effect

“The lecturer Cast a presise spell of Black magic” 

• Digestive

• Castor bean, Precatory bean, Black locust 

• Glycoprotein A-chain depurinates 28s rRNA = inhibition of protein synthesis 

Tropane alkaloids

• Affects which system

• Plants

• Mechanism or effect

“The tight rope holds Jim’s Angel” 

• Digestive 

• Jimsonweed, Angel’s trumpet

• cause anticholingergic toxidrome - decrease GI motility and dry mouth

Insoluble oxalates

• Affects which system

• Plants

• Mechanism or effect

“Only a dummy would eat insoluble crystals” 

• Digestive

• Dumbcane

• Rapid irritation to mouth and GI tract 

Mechanical trauma

• Affects which system

• Plants

• Mechanism or effect

• Digestive

• Foxtail barley, Bristle grass

• barbed bristle cause injury to oral mucosa, skin, ear canal 

Pyrrolizidine Alkaloids

• Affects which system

• Plants

• Mechanism or effect

“The Pyromaniac rattled the rag at the hound”

• Skin/ liver

• Rattlepod, ragwort, hound’s tongue 

• Liver activation of PA’s forms toxic pyrroles = hepatic dz

  • Photosensitation is secondary- damaged liver cannot excrete phylloerythrin

Primary photosensitization

• Affects which system

• Plants

• Mechanism or effect

• skin/ liver

• St John’s wart 

• Photodynamic agent in bloodstream becomes excited by UV light

  • Erythema, edema, photophobia

Plants affecting the blood

• Affects which system

• Plants

• Mechanism or effect

• blood/ circulatory

• Red maple, onions, garlic 

• Hemolytic anemia, oxidative damage 

  • avoid stress, might need a blood transfusion

Hydrolyzable Tannins

• Affects which system

• Plants

• Mechanism or effect

“We like to tan under the giant oak”

• Kidneys

• Oak

• Phenolic acid released from tannins denature cell proteins 

  • severe in cattle, bloody/mucoid feces 

  • Remove access to oak 

Soluble oxalates

• Affects which system

• Plants

• Mechanism or effect

“Sol has a halo and greasy, curly hair”

• Kidneys

• Halogeton, Greasewood, curly dock 

• Toxin forms insoluble Ca and Mg oxalates = crystallization of calcium-oxalate in the kidneys 

Nephrotoxic (unknown)

• Affects which system

• Plants

• Mechanism or effect

“Pigs have bad kidneys”

• Kidneys

• pigweed

• acute tubular necrosis of proximal and distal tubules

  • edema, hemorr, ascites

Steroidal alkaloids

• Affects which system

• Plants

• Mechanism or effect

“The skunk ate corn while high on steroids”

• Repro

• skunk cabbage, corn lily

• toxin is primarily cyclopamine which interferes with signaling during embryogenesis

  • = cyclops offspring

Isocupressic acid

• Affects which system

• Plants

• Mechanism or effect

“Isolation makes you ponder your life choices”

• Repro

• Ponderosa pine

• reduction to uterine flow = release fetal cortisol = abortion

Affecting the musculoskeletal system

• Affects which system

• Plants

• Mechanism or effect

• Musculoskeletal

• Black Walmut

• Toxin in wood/ shavings = severe laminitis = P3 rotation and separation

  • specific to equine, remove the effected bedding

Hind limb paralysis is caused by

Macadamia nuts