what part of the plant is toxic ? :
The leaves and seeds of Creeping Indigo contain Indospicine according to available literature. See the link provided below, on Indospicine studies, under "Tpxicity".
Creeping Indigo contains two toxins:
3-nitropropionate (3-NPA) - A highly toxic compound, produced by the plant primarily as defense against destruction by herbivores. The toxin is a potent and irreversible inhibitor of mitochondrial succinate dehydrogenase, a key enzyme in transforming glucose and oxygen into useable energy. Nerve cells are extremely vulnerable to energy deprivation, thus accounting for the early and prominent neurologic signs seen with all types of 3-NPA toxicity. Because it is metabolized quickly, it is unlikely to be found in the serum of affected animals.
Indospicine - A non-protein amino acid. It is toxic to the liver because of antagonism to the essential amino acid arginine, with which it competes. It is a CUMULATIVE toxin meaning: it builds in their system over a LIFETIME and persists, even after, removal from the weed. One of its principal toxic actions is inhibition of nitric oxide synthase, an action likely associated with the development of corneal edema and ulceration of mucous membranes. Although horses are relatively resistant to the liver damaging effects of this toxin, it persists in the tissues of horses dying or killed with the disease and these tissues are potentially toxic. Indospicine CAN BE detected in the serum of affected animals however, that test is not currently included in U.S. toxicology panels.
How much has to be consumed in order to cause illness has not yet been studied and or published.
3-nitropropionate (3-NPA) - A highly toxic compound, produced by the plant primarily as defense against destruction by herbivores. The toxin is a potent and irreversible inhibitor of mitochondrial succinate dehydrogenase, a key enzyme in transforming glucose and oxygen into useable energy. Nerve cells are extremely vulnerable to energy deprivation, thus accounting for the early and prominent neurologic signs seen with all types of 3-NPA toxicity. Because it is metabolized quickly, it is unlikely to be found in the serum of affected animals.
Indospicine - A non-protein amino acid. It is toxic to the liver because of antagonism to the essential amino acid arginine, with which it competes. It is a CUMULATIVE toxin meaning: it builds in their system over a LIFETIME and persists, even after, removal from the weed. One of its principal toxic actions is inhibition of nitric oxide synthase, an action likely associated with the development of corneal edema and ulceration of mucous membranes. Although horses are relatively resistant to the liver damaging effects of this toxin, it persists in the tissues of horses dying or killed with the disease and these tissues are potentially toxic. Indospicine CAN BE detected in the serum of affected animals however, that test is not currently included in U.S. toxicology panels.
How much has to be consumed in order to cause illness has not yet been studied and or published.