Plant Toxins (L12) Flashcards
(37 cards)
How do plants defend themselves?
- Physical
- Anima Guard
- Visual
- Chemical
Why are some plants poisnous?
- To survive
- Protection/defence from predators
- Could only be harmful to specific things
- Releases chemicals from their roots or fallen leaves so plants cannot grow next to them
What is the source of their poisons?
- Certain ecological conditions such as an accumulation of toxic inorganic materials (such as copper, lead, nitrates, manganese)
Why have people shifted to phytomedicine?
- Belief that herbal remedies are safe
- Dissatisfaction with conventional drugs
- High price of prescription drugs
- Inflated claims of efficacy of herbal-based remedies
- Erroneous belief that herbal products are superior
Which age group are the most likely to be poisoned by plants?
Young children
What factors affect toxicity?
- Genetics
- Geography
- Season
- Age/part of plant
What are some common poisonous parts of a plant?
- Berries/fruits
- Seeds/flowers/leaves
- Stems/roots/bulbs
Some plants can cause skin reactions that could be rashes, inflammation, blisters, etc, what is this known as?
- Allergic or irritant contact dermatisis
Name a few toxic plants
- Death cap (Fatal dose = 1 mushroom)
- Hemlock dropwart (fatal dose = 1 root)
- Ackee (fatal dose = 1 fruit)
Name a few plants that cause skin reactions
- poison ivy, poison oak, poison sumac - Urushiol oil
- Giant hogweed, stinging nettles
- Dieffenbachia
- Agave
name plants can cause gastrointestinal irritation (diarrhoea, vomiting, nausea)
- Amaryllis - bulb
- Buttercup - all parts
- Daffodil - all parts, bulb more potent
- Wisteria - pods
- Mistletoe - berries and leaves
Which toxic protein in Castor Bean Plant seeds cause agglutination of red blood cells
Ricin
What are the symptoms of ricin poisoning from the intake of castor beans?
- Respiratory distress, severe vomiting, multiple organ failure
- Death within 48-72 hours
The beans of the Jequirity Bean plant releases which poison?
Abrin (A chain, B chain)
What are symptoms of Abrin poisoning?
- Stomach cramping
- Vomiting and severe diarrhoea
- Can also inc seizures, liver/kidney failure
What do both Abrin and Ricin inhibit?
Protein synthesis
What are the two major subtypes of Acetylcholine receptors? (AChRs)
- Metabotropic muscarinic receptors
- Ionotropic nicotinic receptors
What are acetylcholine receptors?
An integral membrane protein that responds to the binding of acetylcholine, a neurotransmitter
Which neurotoxin blocks acetycholine receptors?
Curare
- It binds to acetylcholine receptors at the neuromuscular junction and preventing nerve impulses from activating skeletal muscles - Paralysis.
Which neurotoxin is a nicotinic acetylcholine
receptor antagonist that comes from Hemlock?
Coniine - inhibition of the nervous system - causes suffocation in mammals
What are the symptoms of coniine poisoning?
Ataxia, salivation, paralysis, heart & respiratory failure
Which is deadlier, water or poison hemlock?
Water hemlock, can cause death within a few minutes of ingestion
Which toxin comes from water hemlock?
Cicutoxin - acts as a noncompetitive gamma-aminobutyric acid
What are the symptoms of cicutoxin poisoning from ingestion of water hemlock?
severe vomiting, gastrointestinal pain, convulsions, dizziness, salivation, etc
