Melatonin hormonal activity is dependent of daylight period. 6-MBOA is a plant derived cyclic carbamate that has been suggested as a reproductive trigger via a unknown interaction with melatonin. Some workers hypothesize that 6-MBOA is abundant in some plants during early spring when food supply is plenty. Buckwheat is used as a grain source, green forage and green manure crop in Australia and some temperate areas. The seeds and the whole plant used as forage can cause photosensitization in animals exposed to sunlight.
Acute toxicities can produce nervous symptoms as well.
However, some studies did not show toxic effects when Buckwheat replaced wheat or barleyt in pigs diets. This fern is consumed by livestock. It is also considered a gourmet food in Japan and some few other places. Pterosins have been tentatively considered as the bracken-poisoning factor. Widespread hemorrhagy follows with subsequent death.