ALKALOIDS

Question 1

Colchicine plants

Answer 1

• autumn crocus/meadow saffron (most toxic is the ROOT)

- glory lily, climbing lily (flower lives 3-4 days)

Question 2

Colchicine MOA

Answer 2

• ANTIMITOTIC: bind to tubulin and inhibit spindle formation during cell division
• rapidly dividing cells more sensitive

Question 3

Colchicine CS

Answer 3

*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

Question 4

Diterpene alkaloids

Answer 4

Buttercup family:

• larkspur/delphinium
• monkshood/aconite

Question 5

Diterpene alkaloid MOA

Answer 5

competitive blockade of nicotinic receptors at muscle endplate (similar to curare)

Question 6

Diterpene alkaloid CS

Answer 6

• 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)

Question 7

Diterpene alkaloid TX

Answer 7

Physostigmine or neostigmine is an antidote

• physostigmine crosses BBB
• neostigmine does NOT cross BBB

Question 8

Ergot alkaloids

Answer 8

ergot (claviceps purpurea)

Question 9

Ergot MOA

Answer 9

• vasoconstriction and gangrene

- uterine contraction (Ergometrine = abortion contraction in uterus)

Question 10

Ergot CS

Answer 10

• abortion

- hoof and hair abnormalities (can look like Se deficiency)

Question 11

Indolidizine alkaloids

Answer 11

• locoweeds/milk vetches (Astragalus and Oxytropis [though many in these groups are not toxic])
• swainsona canescens (Australia)

Question 12

Indolidizine MOA

Answer 12

• 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

Question 13

Indolidizine CS

Answer 13

• “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)

Question 14

Lyocrine plants

Answer 14

-Amaryllis family:
Narcissus (Daffodil!)
Kaffir lily / caffir lily 
Spider lily 
Barbados lily / fire lily 
Zephyr lily / rain lily
River lily

Question 15

Lyocrine MOA

Answer 15

• emetic and purgative

- bulb is toxic

Question 16

Lyocrine CS

Answer 16

• GI signs: anorexia, salivating, vomiting, diarrhea, hypotension
• large amounts cause muscle tremors and seizures

Question 17

Muscarine plants

Answer 17

poisonous mushroom (amanita muscaria)

Question 18

Muscarine MOA

Answer 18

-stimulates muscarinic receptors of ACh –> post ganglionic PSNS receptors and CNS

Question 19

Muscarine CS

Answer 19

-CNS stimulation signs and muscarinic effects (DUMBELLS)

Question 20

Muscarine TX

Answer 20

• Atropine is an antidote

- symptomatic/decontamination is best)

Question 21

Piperidine alkaloids plants

Answer 21

• poison hemlock/spotted hemlock
• Lupines
• tobacco
• tree tobacco
• coyte tobacco

Question 22

Piperidine alkaloids MOA

Answer 22

• 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

Question 23

Piperidine alkaloid CS

Answer 23

-ataxia, incoordination, birth defects (skeletal malformations and cleft palate)

Question 24

Pyridine plants

Answer 24

-Nightshade family:
tobacco plant
tree tobacco
lobelia

Question 25

Pyridine MOA

Answer 25

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

Question 26

Pyridine CS

Answer 26

- 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

Question 27

Pyrrolizadine plants

Answer 27

- rattlebox/crotalaria - senscio/groundsel/ragwort - heliotrope

Question 28

Pyrrolizadine MOA

Answer 28

Hepatotoxic (hepatogenic photosensitivity) | -can have grave prognosis

Question 29

Solanine and Solanidine plants

Answer 29

-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

Question 30

Solanine and solanidine MOA

Answer 30

GI, CNS, respiratory, and cardiac

Question 31

Taxine alkaloids plants

Answer 31

Yew (Japanese yew in toxic garden) | --> berries look like red-pitted olives

Question 32

Taxine MOA

Answer 32

cardiotoxic and GIT

Question 33

Tropane plants

Answer 33

``` • Jimsonweed/thornapple --> most common! • devil’s trumpet • angel’s trumpet • henbane -deadly nightshade (belladonna) ```

Question 34

Tropane MOA

Answer 34

atropine, hyosine

Question 35

Tropane antidote

Answer 35

Physostigmine (not neostigmine) b/c physostigmine crosses BBB and so does atropine

Question 36

Xanthine plants

Answer 36

cocoa (theobroma cacao) | coffee (coffea arabica)

Question 37

Xanthine MOA

Answer 37

- block adenosine receptors --> increases NE --> CSN stimulation - inhibit phosphodiesterase

Question 38

Xanthine CS

Answer 38

* GIT then CNS stim! - salivation, colic, vomit, diarrhea - CNS stimulation: convulsive seizures, muscle tremors, tachycardia, hypotension, urination