Alterações anátomo-histopatológicas em ratos submetidos à dieta com extrato de broto de samambaia (Pteridium aquilinum var. arachnoideum) de dois municípios do estado do Paraná / Macroscopic and microscopic changes in rats fed on a bracken fern diet (Pteridium aquilinum var. arachnoideum) from different regions of Parana State, Brazil

The carcinogenicity of bracken fern harvest from two regions of Paraná State to induce hematury in rats was studied. In order to do that, 33 Wistar rats were divided in three groups. Groups I and II received an aqueous extract of bracken fern from Londrina-PR or Ibaiti-PR, respectively, in drinking water for 60 days. Group III, control group, received regular plain water with no bracken fern. After 15 months, euthanasia was performed in all animals and samples were collected for histology examination. Histologic analysis revealed that two animals of Group II had ileal adenocarcinoma and soft tissue fibroma of leg.