Plant toxicity Flashcards
Plants most likely to cause serious poisoning in humans:
- Oleander - Nerium oleander 2. Jimson weed - Datura stramonium 3. Jequirty pea - Abrus precatorius 4. Water hemlock - Cicuta maculata 5. Poison Hemlock - Conium maculatum 6. Monkshood - Aconitum napellus
Oleander, especially the yellow Peruvian variety
• Cardiac glycosides oleandrin and digitoxigenin: Highest in seeds, stem, and roots. • Exam alert! Plant cardiac glycosides inhibits Na-K ATP-ase; raises intracellular Na and Ca concentrations; severe poisoning may cause hyperkalemia. • May react with digoxin immunoassay lab test but levels do not correlate with toxicity and cannot be used to guide treatment. o Treatment: Digibind Fab fragments can be used; dose is based on patient response.
Jimson Weed (Datura stramonium)
• Seeds contain the most toxin. Single fruit equals ~6 mg of atropine. • Anticholinergic poisoning: Dry flushed skin, tachycardia, decreased bowel motility, urinary retention, hallucinations, agitation, seizures, and coma. • Onset 30 minutes; duration 48 hours or longer. • Treatment: Benzodiazepines for sedation. • Physostigmine for severe toxicity not responding to benzodiazepines. “Go low, go slow.” Start with a low dose (2 mg) given slowly by IV infusion to avoid bradycardia and heart block. o Physostigmine has very short half-life compared to anticholinergic alkaloids, so repeat dosing or continuous miniscule infusion might be needed.
Toxalbumin group:
Jequirity Pea, Castor Bean • Toxalbumins inhibit cellular protein synthesis and induce cellular injury in various organs. • Jequirty peas (Abrus precatorius) are used to make jewelry. Contains the toxin, abrin. • Castor bean (Ricinis communis) contains the toxin, ricin. The intact bean is surrounded by a hard shell. Even chewed beans rarely result in significant morbidity. o Other plants: Black locust tree (toxin, robin); tropical Florida Sandbox tree (toxin, hurin). • Rapid onset of vomiting, diarrhea, abdominal pain, and delayed multisystem organ failure especially if the exposure is parenteral. • Inhalation of purified toxalbumin (perhaps as a terror event) can lead to rapid airway inflammation/difficulty breathing, myalgia, circulatory failure, death in 36-48 hours.
Water Hemlock
cicutoxin - potent, noncompetitive GABA antagonist. Very toxic! o Nausea, vomiting, diarrhea initially; then CNS excitation: Tremors, seizures, coma. o Plants grow in wet areas, grow up to 6-8 feet tall; with branching, tuberous root stalk like a dahlia. The lower part of the stem is chambered; hollow stems may be purplish. Has divided leaves and clusters (umbels) of white flowers. o All parts contain toxin; roots are the most toxic.
Poison Hemlock
coniine, a nicotine-like alkaloid, in all plant parts but mainly seeds. o Plants grow up to 8-10 feet tall along the dry side of roads and in pastures; has fernlike foliage, mottled purple spots along stems and umbelled flowers that look like wild carrot or Queen Anne’s lace. Has one main solid taproot and stem. o Symptoms similar to nicotine: Stimulation then fatigue of nicotinic receptors in autonomic ganglia, CNS, and skeletal muscle. Nausea, vomiting, hyper then hypotension, bradycardia, muscle weakness, respiratory depression.
Monkshood, Wolfsbane
Aconitum species • Toxin in the root; used in herbal preparations for pain and as an arrow poison. • Aconitine: Causes various neurotoxic and cardiotoxic effects. • Mechanism: Interferes with sodium channel function to induce a chronic depolarization state, at first making it easier to fire cells and to release acetylcholine from nerve terminals. Eventually it paralyzes the nerve. • Mix of GI, neurologic, and cardiovascular effects: GI upset, paresthesia, sweating, muscle cramping then weakness, hypotension, bradycardia or tachycardia, ventricular arrhythmias including Torsades, and death by respiratory paralysis or cardiac arrest.
Oleander
Cardiac glycoside
foxglove
Cardiac glycoside
lily of the valley
Cardiac glycoside
red squill
Cardiac glycoside
balloon cotton
Cardiac glycoside
dogbane
Cardiac glycoside
butterfly weed
(Asclepias) Cardiac glycoside
cane toad
(Bufo marinus) Cardiac glycoside
False or green hellebore
Veratrum alkaloid
Zygadenus venenosus
(death camus) Veratrum alkaloid
black snakeroot
Veratrum alkaloid
certain azaleas
Grayonotoxin
rhododendron
Grayonotoxin
mountain laurel
Grayonotoxin
honey made from pollen
Grayonotoxin
Yew
Contains taxines, which are sodium and calcium channel blockers. -Nausea, vomiting, abdominal pain, bradycardia, conduction delays, hypotension, arrhythmias.
Autumn crocus, glory lily
Colchicine • Purified agent is a drug to treat gout by inhibiting cell division and migration of white cells. • Nausea, vomiting, diarrhea, abdominal pain, and more severe toxicity of bone marrow suppression and multi-organ damage.
Pokeweed
(Phytolacca toxin, saponine, mitogens) - Root contains the most toxins. • Self-limited headache and gastroenteritis, burning sensation in the mouth, intense vomiting, abdominal cramping, hemorrhagic gastritis, frothy diarrhea. • Cooking does not always render safe to eat. If no symptoms in 6 hours most likely will not have any symptoms (true of most GI irritants.)
Philodendron
Insoluble calcium oxalate crystals irritate mouth and throat:
dumbcane
Insoluble calcium oxalate crystals irritate mouth and throat:
caladium
Insoluble calcium oxalate crystals irritate mouth and throat:
elephants ear
Insoluble calcium oxalate crystals irritate mouth and throat:
jack-in-the-pulpit
Insoluble calcium oxalate crystals irritate mouth and throat:
rhubarb
Heavy in soluble oxalates; increased risk of calcium oxalate kidney stones. o Soluble oxalates are perceived as sour/biting when eaten, but it does not contain the needle-like raphide crystals that can pierce the oral mucosa.
Raw or uripe Ackee fruit
Exam alert! Usually affects children who do not yet know to avoid unripe or uncooked fruit. Cooking water also toxic. Imported from Jamaica and found in international grocery stores. o Hypoglycin A causes profound hypoglycemia and intractable vomiting, thus the name of the illness, “Jamaican vomiting sickness.” o Abdominal discomfort begins 2-6 hours after ingestion, followed by sudden onset of vomiting. In severe cases, potentially life-threatening CNS depression. o Hypoglycemia occurs due to inhibition of glucose output by the liver. Microscopically the injury to the liver cells is similar to Reye’s Syndrome. o Treatment: Bedside monitoring of serum glucose; bolus dextrose as needed (D50 adult, D25 older child, D10 young child).
Comfrey/Comfrey tea
Induces hepatic veno-occlusive disease that closes down sinusoids and veins in the liver, causing acute portal hypertension.
Sassafras
Safrole is a potential liver carcinogen; banned by the FDA from commercial food use. Safrole-free sassafras is still OK to use. Filé, a spice used in Cajun cooking, is made from ground sassafras leaves.
Prunus species
(bitter almond, apricot, apple, peach, pear, plum, cherry, etc.) pits and seeds contain amygdalin. o Only bitter almonds and kernels from apricot pits are risky for mild-to-moderate symptoms of acute cyanide toxicity if eaten in reasonably-normal quantities such as 1-2 ounces. o These are typically obtained from the internet or holistic health food/alternative medicine suppliers, not the grocery store.
Cassava
Is a tuber that provides the primary carbohydrate source for much of the world’s tropical and semitropical populations. It is our source of tapioca pudding. Once properly prepared and cooked, the cyanogenic glycoside isgone and it is safe. If not properly prepared, it supplies small amounts of cyanide. o Chronic, low-level cyanide exposure is associated with the development of goiter and with tropical ataxic neuropathy, a neurologic disorder that renders a person unsteady and uncoordinated. o Severe sub-acute dietary cyanide poisoning from eating a particular variety, “bitter cassava”, particularly during famines, is associated with outbreaks of an irreversible, debilitating, spastic paralytic disorder called Konzo.
Veratrum alkaloids
Severe nausea and vomiting, then bradycardia, heart block, syncope, diaphoresis, weakness, hypotension.
Grayanotoxins
Salivation, burning mouth, perioral numbness, nausea, vomiting, dizziness, diaphoresis, significant hypotension and bradycardia.
