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

Timothy S Murbach; Róbert Glávits; Gábor Hirka; John R Endres; Amy E Clewell; Ilona Pasics Szakonyiné

doi:10.1016/j.toxrep.2017.09.002

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

Toxicol Rep. 2017 Sep 12:4:494-501. doi: 10.1016/j.toxrep.2017.09.002. eCollection 2017.

Authors

Timothy S Murbach¹, Róbert Glávits², Gábor Hirka², John R Endres¹, Amy E Clewell¹, Ilona Pasics Szakonyiné²

Affiliations

¹ AIBMR Life Sciences, Inc., 2800 East Madison Street, Suite 202, Seattle, WA, 98112, USA.
² Toxi-Coop Zrt., Magyar Jakobinusok tere 4/B, H-1122 Budapest, Hungary.

Abstract

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.

Keywords: A/G ratio, albumin to globulin ratio; ANOVA, analysis of variance; BALT, bronchus associated lymphoid tissue; FOB, functional observation battery; Fernblock; MTD, maximum tolerated dose; NOAEL; NOAEL, no observed adverse effect level; OECD, Organisation for Economic Cooperation and Development; Photoprotection; Polypodium leucotomos; SPF, specific pathogen free; Toxicity; Toxicology.