Definition
Description
Lotaustralin Health Effects
General Information
- Metabolism: Upon exposure to enzymes and gut flora in the human intestine, lotaustralin can decompose to the toxic chemical hydrogen cyanide. This occurs via the enzyme linamarase, which is found in the cell wall of the plant. Chewing of the plant allows the enzyme to contact the lotaustralin converting it into acetone cyanohydrin, which then spontaneously decomposes to hydrogen cyanide. (L630, L1240) Organic nitriles are converted into cyanide ions through the action of cytochrome P450 enzymes in the liver. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Cyanide metabolites are excreted in the urine. (L96)
- Uses/Sources: Lotaustralin is a plant toxin found in the roots and leaves of plants such as cassava (Manihot esculenta), lima bean (Phaseolus lunatus), roseroot (Rhodiola rosea) and white clover (Trifolium repens). (L1240)
- Health Effects: Dietary exposure to lotaustralin has been reported as a risk factor in developing glucose intolerance and diabetes. It may also cause the upper motor neuron disease known as konzo. (L630, L1240)
- Symptoms: Cyanide poisoning is identified by rapid, deep breathing and shortness of breath, general weakness, giddiness, headaches, vertigo, confusion, convulsions/seizures and eventually loss of consciousness. (L96, L97)
- Route of Exposure: Oral
Mechanism of Action
Target Name | Mechanism of Action | References |
---|---|---|
Glutathione reductase, mitochondrial | Cyanide inhibits glutathione reductase. (A76) |
2734799 |
Tyrosinase | Cyanide inhibits tyrosinase. (A77) |
16950829 |
Cytochrome c oxidase subunit 1 Cytochrome c oxidase subunit 2 Cytochrome c oxidase subunit 3 Cytochrome c oxidase subunit 4 isoform 1, mitochondrial Cytochrome c oxidase subunit 5A, mitochondrial Cytochrome c oxidase subunit 5B, mitochondrial Cytochrome c oxidase subunit 6A1, mitochondrial Cytochrome c oxidase subunit 6A2, mitochondrial Cytochrome c oxidase subunit 6B1 Cytochrome c oxidase subunit 6C Cytochrome c oxidase subunit 7A1, mitochondrial Cytochrome c oxidase subunit 7A2, mitochondrial Cytochrome c oxidase subunit 7B, mitochondrial Cytochrome c oxidase subunit 7C, mitochondrial Cytochrome c oxidase subunit 8A, mitochondrial Cytochrome c oxidase subunit 6B2 Cytochrome c oxidase subunit 4 isoform 2, mitochondrial Cytochrome c oxidase subunit 7B2, mitochondrial Cytochrome c oxidase subunit 8C, mitochondrial |
Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. (L97) |
|
Succinate dehydrogenase cytochrome b560 subunit, mitochondrial Succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial Succinate dehydrogenase [ubiquinone] flavoprotein subunit, mitochondrial Succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial |
Cyanide inhibits succinate dehydrogenases. (A76) |
2734799 |
Alkaline phosphatase, tissue-nonspecific isozyme Alkaline phosphatase, placental-like |
Cyanide inhibits alkaline phosphatases. (A73) |
924371 |
Glutathione peroxidase 1 Glutathione peroxidase 2 Glutathione peroxidase 3 Phospholipid hydroperoxide glutathione peroxidase, mitochondrial Epididymal secretory glutathione peroxidase Glutathione peroxidase 6 Glutathione peroxidase 7 Probable glutathione peroxidase 8 |
Cyanide inhibits glutathione peroxidases. (A75) |
7437059 |
Catalase | Cyanide inhibits catalase. (A74) |
16728955 |
Superoxide dismutase [Cu-Zn] Extracellular superoxide dismutase [Cu-Zn] |
Cyanide inhibits superoxide dismutase [Cu-Zn]. (A72) |
15856906 |