Cycasin

[3] It induces hepatotoxicity and Zamia staggers, a fatal nervous disease affecting cattle resulting from browsing on the leaves or other parts of cycads.

The origin and biological role of these toxins is unknown, as there does not appear to be a statistically significant correlation between the concentration of toxic material and the types of herbivory observed in animals consuming the plants.

Treatment with β-glucosidase causes cycasin to release methylazoxymethanol (MAM), which spontaneously decomposes to form formaldehyde and methyldiazonium.

It is clinically characterized by weight loss followed by lateral swaying of the hind quarters, with weakness, ataxia, and proprioceptive defects in the rear limbs, and results in demyelination and axonal degeneration in the brain, spinal cord, and dorsal root ganglia.

Starches prepared from the seeds of a native cycad species, Cycas micronesica, are used to create the sago-like flour fadang, which forms a major part of the diet of the Chamorro people.

As the seeds contain the highest amount of the toxin found in the plant, it was proposed that a dietary explanation relating to the consumption of poorly processed fadang was poisoning the natives.

The bats accumulate BMAA in their fat by consuming cycad seeds, resulting a in a high concentration of the neurotoxin.

Chemical structure of cycasin
Cycas micronesica , one of the cycad species consumed by the Chamorro