Study Set Content:
• These two types of peppers produce the major irritants ()(). Specific nerves in the airway have been found to be capsaicin-sensitive, which leads to the irritation and cough.
capsaicin and dihydrocapsaicin
Ingestion of toxic plant can cause()()often resulting in nausea, vomiting, and diarrhea.
irritation of the gastrointestinal tract
are found in buffalo beans. Ingestion by children causes nausea, vomiting, dizziness, and abdominal discomfort.
Toxic quinolizidine alkaloids
Nuts from Aesculus hippocastanum (horse chestnut) and Aesculus glabra (Ohio buckeye contain a glucoside called (). Ingestion by humans causes gastroenteritis
Esculin
is found in Podophyllum peltatum (May apple, Berberidaceae) especially in its foliage and roots. • In low doses, mild purgation occurs; however, overdose results in nausea and severe paroxysmal vomiting. By binding microtubules, podophyllotoxin blocks mitosis from proceeding.
Podophyllotoxin
The family Euphorbiaceae contains several genera that are known to be very toxic. • Castor bean (Ricinus communis), toxic agents are two lectins found in the beans:
ricin I and ricin II
Castor bean (Ricinus communis), toxic agents are two lectins found in the beans: ricin I and ricin II of which ricin() is more toxic
II
is made up of an A-chain and a B-chain. B-chain is responsible for helping the A-chain get inside the cell. Once inside, the A-chain inactivates the 60s ribosomal subunit of cells by catalytic depurination of an adenosine residue within the 28s rRNA, thereby blocking protein synthesis
Rincin II
Various plants that contain cardioactive glycosides include ()(), which contains , () etc. • The cardiac glycosides inhibit Na+, K+ -ATPase.
Digitalis purpurea, squill (Scilla maritima), lily of the valley, scillaren, milkweeds
Toxic alkaloids found in ()()() cause nausea, emesis, hypotension, and bradycardia on ingestion.
Veratrum viride(American hellebore, Liliaceae), Veratrum album (European hellebore), and Veratrum californicum
A mixture of alkaloids includes ()that affects the heart by causing a repetitive response to a single stimulus resulting from prolongation of the sodium current.
protoveratrine, veratramine, and jervine
() species causes not only cardiac arrhythmias and hypotension, but ingestion causes gastrointestinal upset and neurological symptoms. o Works by causing a prolonged sodium current with slowed repolarization of cardiac muscle and nerve fibers.
Aconitum
mad honey poisoning bind to sodium channels in cardiac and muscle cells resulting in increased sodium conductance
• Grayanotoxins
produces a toxin (phoratoxin and viscotoxin). It causes hypotension, vasoconstriction of the vessels in skin and skeletal muscle, and bradycardia resulting from negative inotropic actions on heart muscle.
Mistletoe
Ingestion of the fungus () (ergot) which grows on grains that are used for food, causes vasoconstriction. o In extreme cases, the vasoconstriction was severe enough that () would develop in the extremities. Abortion in pregnant women is a so common after ingestion of ergotcontaminated grains.
Claviceps purpure, gangrene
Ingestion of significant concentrations of () alkaloids causes liver damage in the form of hepatic venoocclusive disease associated with lipid peroxidation.
pyrrolizidine
Cattle that graze on grass contaminated with • ()and consumption of contaminated wheat crops. • Liver damage caused by ingestion clinically appears to be similar to cirrhosis and some hepatic tumors that can easily be mistaken to be the source of the disease.
Senecio
Repeated ingestion of false morel, () has been found to cause hepatitis. o Boiling generally inactivates the toxin gyromitrin.
, Gyromitra esculenta,
contain phalloidin and amatoxins. () is capable of binding actin in muscle cells; however, it is not readily absorbed during digestion. Smaller α-, β-, and γ-amanitins are readily absorbed.
Amanita phalloides, Phalloidin
is the most toxic as it inhibits protein synthesis in hepatocytes by binding to RNA polymerase II. It also irreversibly inhibits acetylcholinesterase.
α-amanitin
