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

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: Polypodium leucotomos, Toxicology, Toxicity, Fernblock, NOAEL, Photoprotectio

An Assessment of the Genotoxicity and Subchronic Toxicity of a Supercritical Fluid Extract of the Aerial Parts of Hemp

A battery of toxicological studies was conducted on a supercritical CO2 extract of the aerial parts of the Cannabis sativa plant, containing approximately 25% cannabinoids. No evidence of genotoxicity was found in a bacterial reverse mutation test (Ames), in an in vitro mammalian chromosomal aberration test, or in an in vivo mouse micronucleus study. A 14-day repeated oral dose-range finding study conducted in Wistar rats at 1000, 2000, and 4000 mg/kg bw/day resulted in effects where a NOAEL could not be concluded. Based on those results, a 90-day repeated dose oral toxicity study was performed in rats using doses of 100, 360, and 720 mg/kg bw/day, followed by a 28-day recovery period for two satellite groups. Significant decreases in body weight, body weight gain, and differences in various organ weights compared to controls were observed. At the end of the recovery period, many of the findings were trending toward normal; thus, the changes appeared to be reversible. The NOAEL for the hemp extract in Hsd.Han Wistar rats was considered to be 100 mg/kg bw/day for males and 360 mg/kg bw/day for females