Plant toxicity review

Question 1

Plant toxicity to skin

Answer 1

Allergic dermatitis.
Contact dermatitis (oral; don’t need initial exposure).
Mechanical injury.
Contact Urticaria ( local vasodilation, stinging and pain).
Phototoxcity ( containsfurocoumarins).
Primary chemical irritation (resembles corrosive acids; eye damage possible; affected by temp and humidity).

Question 2

Plant toxicity to GI

Answer 2

Direct stomach irritation (N/V/D).
Antimitotic (by colchicine (gout tx) N/V, confusion, delirium).
Lectin toxicity (castor beans/ricin; N/D, HA, confusion, death).

Question 3

Plant toxicity to CV system

Answer 3

Digitalis-like glycosides (foxglove, lily of the valley; drug for CHF; N/V, arrhythmias).
Mistletoe (berries; phoratoxin produces hypotention, bradycardia, vasoconstriction of skin and skeletal muscle).
Ergot (fungus parasitic on grains; “St. Anthony’s fire”).
Heart nerves (alkaloids, aconitum and grayanotoxin; can concentrate in honey; decreased HR, hypotension, weakness).

Question 4

Plant toxicity in liver

Answer 4

Hepatitis and cirrhosis (ragwort or groundsel)
Liver failure and death (“death cap”; amatoxin and phalloidin affects RNA and protein synthesis).
Liver CA (alfatoxins: carcinogen).

Question 5

Plant toxicity in NS

Answer 5

Seizures (water hemlock).
Stimulation (red alga, green alga/domoic acid), aberrant behavior (locoweed), neurotoxic (poison hemlock/coniine), paralysis (buckthorn, coyotillo, tullidora), atropine-like effects (jimsoonweed, henbane, deadly nightshade), neuromuscular (tabacco, blue-green alga).

Question 6

Plant toxicity in reproductive system

Answer 6

teratogen (veratrum: blocks cholesterol synthesis) and abortifacients (legumes, bitter melon seeds, swainsonine toxin/ lectins).

Question 7

Jimson Weed

Answer 7

Deadly-nightshade plant.
Can extract atropine (for OP toxicity).
Both poison and cure.
Used as eye cream

Question 8

Cyclopeptide-containing mushrooms

Answer 8

“death angel,” “death cap,” “destroying angel.”.
Sx include gastroenteritis, hepatic/renal failure and death.
Toxin is heat-stable.
Alpha-aminitin interferes with RNA pol. II
Phalotoxin interrupts actin polymerization.
Tx: charcoal lavage, watch for AMS and hypoglycemia.
Antidotes: penicillin, n-acetylcysteine, thioctic acid, liver transplant.

Question 9

Monomethylhydrazine-containing mushrooms

Answer 9

Toxin: gyromitrin metabolized to monomethylhydrazine (inhibits pyridoxal phosphate-related enzyme).
Destroyed by heat.
Sx: HA, N/V, seizure, hepatorenal failure.
Tx: pyridoxine.

Question 10

Coprine-containing mushroom

Answer 10

Toxin: disulfiram-like effect (blocks acetaldehyde dehydrogenase).
Used to counteract methanol toxicity.
Toxic if alcohol is consumed within 48-72 hrs.
Sx: flushing. hypotension, vasodilation.
Tx: anti-H1, anti-H2, prostaglandin inhibitors

Question 11

Ricin

Answer 11

cytotoxin in castor beans.
destroyed by heat.
stalk and leaf of plant are mildly toxic.
blocks protein synthesis–cell death.
Sx: fever, cough, nausea, sweat, chest tightness, hypotension, dyspnea, circulatory/resp collapse.
MOA: ricin 1 < ricin 2 more toxic.
Ricin 2 inactivates the 60s ribosomal subunit by depurinating 1 aa.
No anti-toxin available.

Question 12

Colchicine

Answer 12

anti-inflammatory effects by inhibiting microtubules and PMN activities (used to tx gout).
May cross placenta and mammary barrier.
Sx: abd pain, N/V/D, skin irritation.
renal/resp/cardiac failure, pancytopenia, aplastic anemia, acidosis, blood clotting, convulsion.
Recovery: leukocytosis and alopecia.