A toxicological evaluation of a fulvic and humic acids preparation.

Humic substances are ubiquitous in soils and waters. These complex superstructures are derived from the decomposition of dead plant and animal matter and are vital to soil health. Their heterogenous composition is specific to their site of origin and is comprised of weakly bound aggregates of small organic compounds that can sequester minerals and make them available to plants. As such, they may possess potential nutritional value for humans, and extractions of fulvic and humic acids can be produced that could be suitable for such purposes. For this reason, we evaluated the toxicological profile of a specific preparation (blk. 333) of fulvic and humic acids derived from a lignite deposit in Alberta, Canada and found it to lack genotoxic potential in a bacterial reverse mutation test, in vitro mammalian chromosomal aberration test, and in vivo mammalian micronucleus test. No general or organ toxicity was observed in Wistar rats following 90 days of continuous exposure, and a no observed adverse effect level (NOEAL) was determined at 2000 mg/kg bw/day, the highest tested dose. Our results suggest the feasibility of further evaluation for development of the preparation as a nutritional supplement in food.

A comprehensive toxicological safety assessment of an extract of Ageratum conyzoides.

A battery of toxicological studies was conducted to aid in the safety assessment of an ethanolic extract of Ageratum conyzoides for use as an ingredient in food. In accordance with internationally accepted standards, a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, an in vivo mammalian micronucleus test, and a 90-day repeated-dose oral toxicity study in rats were performed. In the first three applied test systems, no evidence of mutagenicity, clastogenicity or genotoxicity was revealed. Ageratum conyzoides did not cause mortality or toxic changes in Hsd.Han Wistar rats in the 90-day repeated dose oral (gavage) toxicity study at doses of 500, 1000 and 2000 mg/kg bw/d. The NOAEL was determined to be 2000 mg/kg bw/d for both male and female rats, the highest dose tested.

A 28-Day Repeated Dose Toxicological Study of an Aqueous Extract of Morus Alba L.

Morus alba L. (white mulberry) leaves are one of the oldest recognized traditional Chinese medicines. More recently, M alba leaves and their constituents, particularly iminosugars (or azasugars), have garnered attention for their ability to maintain normal blood glucose concentrations, an effect identified in both animal studies and human clinical trials. Reducose (Phynova Group Limited) is a commercial water-soluble extract of M alba leaves standardized to 5% 1-deoxynojirimycin (DNJ), an iminosugar with α-glucosidase inhibition properties. Although there is an extensive history of consumption of M alba leaves by humans and animals worldwide, suggesting that the leaves and their extracts have a relatively good safety profile, we are unaware of safety assessments on an extract containing a higher amount of DNJ than that occurs naturally. The current 28-day repeated dose oral toxicity study in rats, conducted according to Organisation for Economic Co-operation and Development guidelines, was carried out to assess the safety of Reducose. Male and female Hsd.Han Wistar rats (4 groups of 10 animals/sex) were administered Reducose via gavage at doses of 0, 1,000, 2,000 and 4,000 mg/kg body weight (bw)/d. No treatment-related mortality or adverse effects (per clinical observations, body weight/weight gain, food consumption, ophthalmoscopy, clinical pathology, gross pathology, organ weights, or histopathology) were observed, and no target organs were identified. The no observed adverse effect level was determined to be 4,000 mg/kg bw/d for both male and female rats, the highest dose tested.

A Comprehensive Toxicological Safety Assessment of an Extract of Olea Europaea L. Leaves (Bonolive™).

A battery of toxicological studies was conducted to investigate the genotoxicity and repeated-dose oral toxicity of Bonolive™, a proprietary water-soluble extract of the leaves of the olive tree (Olea europaea L.), in accordance with internationally accepted protocols. There was no evidence of mutagenicity in a bacterial reverse mutation test and in an vitro mammalian chromosomal aberration test nor was any genotoxic activity observed in an in vivo mouse micronucleus test at concentrations up to the limit dose of 2000 mg/kg bw/d. Bonolive™ did not cause mortality or toxic effects in Crl:(WI)BR Wistar rats in a 90-day repeated-dose oral toxicity study at doses of 360, 600, and 1000 mg/kg bw/d. The no observed adverse effect level in the 90-day study was 1000 mg/kg bw/d for both male and female rats, the highest dose tested.

A comprehensive toxicological safety assessment of an aqueous extract of Polypodium leucotomos (Fernblock(®)).

A battery of toxicological studies was conducted in accordance with internationally accepted standards to investigate the genotoxicity and repeated-dose oral toxicity of Fernblock(®), a commercial aqueous extraction of the leaves of the tropical fern Polypodium leucotomos used for its oral and topical photoprotective properties. No evidence of mutagenicity was observed in a bacterial reverse mutation test or in vitro mammalian chromosomal aberration test nor was any genotoxic activity observed in an in vivo mouse micronucleus test. Two repeated-dose oral toxicity studies were conducted in male and female Wistar rats. In the first study, no mortality or toxic effects were observed and no target organs were identified at doses administered for 14 days by gavage up to the maximum dose of 5000 mg/kg bw/day. Based on these results, a 90-day study was conducted at 0, 300, 600, and 1200 mg/kg bw/day. No mortality or treatment-related adverse effects were observed and no target organs were identified. The NOAEL from the 90-day study was determined to be 1200 mg/kg bw/day, the highest dose tested.

Safety assessment of a hydroethanolic extract of Caralluma fimbriata.

This toxicological assessment evaluated the safety of a hydroethanolic extract prepared from Caralluma fimbriata (CFE), a dietary supplement marketed worldwide as an appetite suppressant. Studies included 2 in vitro genotoxicity assays, a repeated dose oral toxicity study, and a developmental study in rats. No evidence of in vitro mutagenicity or clastogenicity surfaced in the in vitro studies at concentrations up to 5000 µg of extract/plate (Ames test) or 5000 µg of extract/mL (chromosomal aberration test). No deaths or treatment-related toxicity were seen in the 6-month chronic oral toxicity study in Sprague-Dawley rats conducted at 3 doses (100, 300, and 1000 mg/kg body weight (bw)/d). The no observed effect level for CFE in this study was considered to be 1000 mg/kg bw/d. A prenatal developmental toxicity study conducted at 3 doses (250, 500, and 1000 mg/kg bw/d) in female Sprague-Dawley rats resulted in no treatment-related external, visceral, or skeletal fetal abnormalities, and no treatment-related maternal or pregnancy alterations were seen at and up to the maximum dose tested. CFE was not associated with any toxicity or adverse events.

Safety evaluation of a natural eggshell membrane-derived product.

Natural Eggshell Membrane (NEM®) is a novel dietary ingredient that contains naturally occurring glycosaminoglycans and proteins essential for maintaining healthy joint and connective tissues. NEM® was evaluated for safety via in vitro and in vivo toxicological studies. This included testing for cytotoxicity, genotoxicity, acute oral toxicity, and 90-day repeated-dose oral toxicity. NEM® did not exhibit any cytotoxic effects at a dose of 100 µg in an in vitro human cell viability assay after incubation for up to 20 h. NEM® did not exhibit any genotoxic effects in an in vitro assay of four strains of histidine-dependent Salmonella typhimurium and one strain of tryptophan-dependent Escherichia coli at a dose of up to 5000 µg/plate. NEM® did not exhibit any signs of acute toxicity in rats at a single oral dose of up to 2000 mg/kg body weight, nor signs of toxicity (via urinalysis, hematology, clinical chemistry, or histopathological evaluation) in rats at a repeated oral dose of up to 2000 mg/kg body weight per day for 90 days. The results of these studies suggest that NEM® may be safe for human consumption.