thiaminase/ワラビ

Thiaminase type 1 and 2 activities and thiamine content of five plants were determined. Of these Pteridium aquilinum and Equisetum ramosissimum were found to have considerably more thiaminase activity and lower thiamine content than Malva parviflora, Pennisetum clandestinum and Medicago sativa.

Bracken fern (Pteridium aquilinum) is the fifth most distributed common weed species of the world. Its ecological distribution is very wide, and the plant can grow and spread successfully on many types of soil. The cover of P. aquilinum is--in some cases--remarkable (e.g., in the United Kingdom).

Thiaminase induced thiamine deficiency occurs in fish, humans, livestock and wild animals. A non-radioactive thiaminase assay was described in 2007, but a direct comparison with the radioactive 14C-thiamine method which has been in use for more than 30 years has not been reported. The objective was

Polioencephalomalacia (PEM) was induced in sheep, with an overall incidence of 63 per cent, using local bracken fern (Pteridium esculentum) rhizomes as a source of thiaminase type 1 and pyridine as a basic cosubstrate. The condition was thiamin responsive and PEM was confirmed by histopathological