ALKALOIDS Flashcards
Colchicine plants
- autumn crocus/meadow saffron (most toxic is the ROOT)
- glory lily, climbing lily (flower lives 3-4 days)
Colchicine MOA
- ANTIMITOTIC: bind to tubulin and inhibit spindle formation during cell division
- rapidly dividing cells more sensitive
Colchicine CS
*ALL ORGANS ARE INVOLVED
-GI signs including stomatitis, nausea, vomiting, diarrhea, and GI hemorrhage
-CV signs including hypotension and cardiac arrhythmias
-Respiratory signs
-Renal failure
-Hepatic failure
-Seizure and neuronal signs
-Coagulopathies
-Myelosuppression
Diterpene alkaloids
Buttercup family:
- larkspur/delphinium
- monkshood/aconite
Diterpene alkaloid MOA
competitive blockade of nicotinic receptors at muscle endplate (similar to curare)
Diterpene alkaloid CS
- sudden death in cattle
- early signs are of NM blockade including: weakness, staggering, stiffness, trembling, black, recumbency, collapse
- death d/t muscle paralysis –> asphyxia
- Monkshood: cardiac arrhythmias (cardiotoxic)
Diterpene alkaloid TX
Physostigmine or neostigmine is an antidote
- physostigmine crosses BBB
- neostigmine does NOT cross BBB
Ergot alkaloids
ergot (claviceps purpurea)
Ergot MOA
- vasoconstriction and gangrene
- uterine contraction (Ergometrine = abortion contraction in uterus)
Ergot CS
- abortion
- hoof and hair abnormalities (can look like Se deficiency)
Indolidizine alkaloids
- locoweeds/milk vetches (Astragalus and Oxytropis [though many in these groups are not toxic])
- swainsona canescens (Australia)
Indolidizine MOA
- inhibit lysosomal enzymes essential for formation of glycoproteins
- alteration of cellular function in the brain and many other organs
-Astragalus and Oxytropis also have nitropropanol glycoside and selenium –> niropropanol causes peripheral neuronal degeneration and respiratory signs and selenium causes abnormal hoof and hair
Indolidizine CS
- “Locoism”
- neuronal signs / brain damage CS
- more common in horses than sheep/cattle
- depression, incoordination, ataxia, circling, weird behavior
(other: infertility, congenital defects, heart failure, weight loss, poor performance, decreased immune function)
Lyocrine plants
-Amaryllis family: Narcissus (Daffodil!) Kaffir lily / caffir lily Spider lily Barbados lily / fire lily Zephyr lily / rain lily River lily
Lyocrine MOA
- emetic and purgative
- bulb is toxic
Lyocrine CS
- GI signs: anorexia, salivating, vomiting, diarrhea, hypotension
- large amounts cause muscle tremors and seizures
Muscarine plants
poisonous mushroom (amanita muscaria)
Muscarine MOA
-stimulates muscarinic receptors of ACh –> post ganglionic PSNS receptors and CNS
Muscarine CS
-CNS stimulation signs and muscarinic effects (DUMBELLS)
Muscarine TX
- Atropine is an antidote
- symptomatic/decontamination is best)
Piperidine alkaloids plants
- poison hemlock/spotted hemlock
- Lupines
- tobacco
- tree tobacco
- coyte tobacco
Piperidine alkaloids MOA
- piperidine alkaloids include ANABASINE (in tobacco), CONIINE (from poison hemlock), and AMMONDENDRENE (from lupines)
- piperidine alkaloids have nicotinic effects starting with ganglionic and neuromuscular stimulation followed by ganglionic and neuromuscular blockade
- Neuromuscular blockade prevents fetal movement resulting in birth defects
Piperidine alkaloid CS
-ataxia, incoordination, birth defects (skeletal malformations and cleft palate)
Pyridine plants
-Nightshade family:
tobacco plant
tree tobacco
lobelia
Pyridine MOA
Nicotine and lobeline act on nicotinic receptors at autonomic ganglia, neuromuscular junction and some synapses in the CNS
- low doses cause depolarization
- high doses cause blockade
Pyridine CS
- Rapid onset of clinical signs
- Early signs are excitation, salivation, lacrimation, vomiting, diarrhea, and tachypnea
- Muscle twitching, muscle weakness, and dyspnea
- Death is due to respiratory failure
Pyrrolizadine plants
- rattlebox/crotalaria
- senscio/groundsel/ragwort
- heliotrope
Pyrrolizadine MOA
Hepatotoxic (hepatogenic photosensitivity)
-can have grave prognosis
Solanine and Solanidine plants
-black nightshade (*NIGHTSHADE very important) –> berries start out green (more toxic) then become black
- American nightshade
– eggplant (immature)
– tomato (immature – green)
– turkey berry
– Chinese lantern
Solanine and solanidine MOA
GI, CNS, respiratory, and cardiac
Taxine alkaloids plants
Yew (Japanese yew in toxic garden)
–> berries look like red-pitted olives
Taxine MOA
cardiotoxic and GIT
Tropane plants
• Jimsonweed/thornapple --> most common! • devil’s trumpet • angel’s trumpet • henbane -deadly nightshade (belladonna)
Tropane MOA
atropine, hyosine
Tropane antidote
Physostigmine (not neostigmine) b/c physostigmine crosses BBB and so does atropine
Xanthine plants
cocoa (theobroma cacao)
coffee (coffea arabica)
Xanthine MOA
- block adenosine receptors –> increases NE –> CSN stimulation
- inhibit phosphodiesterase
Xanthine CS
- GIT then CNS stim!
- salivation, colic, vomit, diarrhea
- CNS stimulation: convulsive seizures, muscle tremors, tachycardia, hypotension, urination
