A 28-day oral toxicology study of an aqueous extract of Polypodium leucotomos (Fernblock ? )

摘要

Fernblock? is a standardized commercial aqueous extraction of the leaves of the tropical fern Polypodium leucotomos promoted as an orally active photoprotective substance. In a previous battery of toxicological tests on Fernblock?, no genotoxicy was observed and no oral toxicity was observed up to 1200 mg/kg bw/day. The current study was conducted in Hsd.Han Wistar rats using doses of 0, 2000, 3500, and 5000 mg/kg bw/day Fernblock? by gavage for 28 consecutive days. No mortality or toxic effects were observed and no target organs were identified. The no observed adverse effect level was determined to be 5000 mg/kg bw/day, the highest dose tested.