An evaluation of the genotoxicity and 90-day repeated-dose toxicity of a CBD-rich hemp oil.

Currently, there is much interest in the sales and study of consumable Cannabis sativa L. products that contain relatively high levels of cannabidiol (CBD) and low levels of Δ-9-tetrahydrocannabinol. While there are published safety evaluations for extracts containing low concentrations of CBD, toxicological assessments for those with higher concentrations are still scant in the public domain. In this paper, genotoxicity tests and a 90-day repeated-dose toxicity study of an ethanolic extract of C. sativa containing ~85% CBD were performed following relevant OECD guidelines. No increased gene mutations were observed in a bacterial reverse mutation assay compared to controls up to the maximum recommended concentration of the guideline. An in vitro chromosomal aberration assay showed no positive findings in the short-term (3 h) treatment assays. Long-term treatment (20 h) showed an increased number of cells containing aberrations at the highest dose of 2 µg/mL, which was outside of historical control levels, but not statistically significantly different from the controls. An in vivo micronucleus study showed no genotoxic potential of the test item in mice. A 90-day repeated-dose gavage study using 0, 75, 125, and 175 mg/kg bw/day showed several slight findings that were considered likely to be related to an adaptive response to consumption of the extract by the animals but were not considered toxicologically relevant. These included increases in liver and adrenal weights compared to controls. The NOAEL was determined as 175 mg/kg bw/day, the highest dose tested (equivalent to approximately 150 mg/kg bw/day of CBD).

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 Toxicological Evaluation of Mango Leaf Extract (Mangifera indica) Containing 60% Mangiferin.

A battery of OECD- and GLP-compliant toxicological studies was performed on mango leaf extract (Mangifera indica) containing 60% mangiferin (MLE). No evidence of genotoxicity was found in a bacterial reverse mutation test (Ames). While evidence of clastogenic activity was noted in an in vitro chromosomal aberration test, an in vivo mammalian micronucleus test showed no findings up to the limit dose (2000 mg/kg bw). A 90-day repeated dose oral toxicity study was conducted in rats using doses of 0 (vehicle control), 500, 1000, and 2000 mg/kg bw/day. Based on the lack of mortality or toxic effects in the 90-day study, the NOAEL for MLE in Han:Wist male and female rats was determined to be 2000 mg/kg bw/day, the highest dose tested.

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 Toxicological Evaluation of Methylliberine (Dynamine®).

Methylliberine (CAS 51168-26-4), a methoxiuric acid, is a caffeine metabolite present at low levels in various Coffea plants; however, very little has been published regarding this compound and we could find no toxicological data in the public domain. Therefore, we undertook the toxicological investigation of a pure, synthetic form of methylliberine in order to evaluate its potential health hazards as a food ingredient. A (1) bacterial reverse mutation test, (2) in vitro mammalian chromosomal aberration test, (3) in vivo mammalian micronucleus test, and (4) 90-day repeated-dose oral toxicity study in rats with a 28-day recovery period were conducted. No in vitro mutagenic or clastogenic activity was observed in the presence or absence of metabolic activation up to the maximum OECD recommended test concentrations. No genotoxicity was observed in the mammalian micronucleus study up to the highest dose tested of 700 mg/kg bw. In the 90-day study, methylliberine was administered to Han:WIST rats at doses of 0, 75, 112, 150, 187, and 225 mg/kg bw/day. No mortality or morbidity was observed and no toxicologically relevant clinical effects or effects on clinical pathology parameters were observed. In male animals, test item-related effects on body weight and sexual organs, which were not reversible after a 28-day recovery period without treatment, were observed in the high-dose group. Body weight development was also slightly and reversibly depressed in the 187 mg/kg bw/day male group. No toxicological effects were observed in females. The NOAEL for females was determined to be 225 mg/kg bw/day, the highest dose tested, while the NOAEL for males was determined to be 150 mg/kg bw/day. Future studies are encouraged to corroborate the safety, and assess efficacy, of methylliberine in humans.

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.

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.

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 90-Day Oral Toxicological Evaluation of the Methylurate Purine Alkaloid Theacrine.

A 90-day repeated-dose oral toxicological evaluation was conducted according to GLP and OECD guidelines on the methylurate purine alkaloid theacrine, which is found naturally in certain plants. Four groups of Hsd.Brl.Han Wistar rats (ten/sex/group) were administered theacrine by gavage doses of 0 (vehicle only), 180, 300, and 375 mg/kg bw/day. Two females and one male in the 300 and 375 mg/kg bw/day groups, respectively, died during the study. Histological examination revealed centrilobular hepatocellular necrosis as the probable cause of death. In 375 mg/kg bw/day males, slight reductions in body weight development, food consumption, and feed efficiency, decreased weight of the testes and epididymides and decreased intensity of spermatogenesis in the testes, lack or decreased amount of mature spermatozoa in the epididymides, and decreased amount of prostatic secretions were detected at the end of the three months. At 300 mg/kg bw/day, slight decreases in the weights of the testes and epididymides, along with decreased intensity of spermatogenesis in the testes, and lack or decreased amount of mature spermatozoa in the epididymides were detected in male animals. The NOAEL was considered to be 180 mg/kg bw/day, as at this dose there were no toxicologically relevant treatment-related findings in male or female animals.

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.

Effect of the novel low molecular weight hydrolyzed chicken sternal cartilage extract, BioCell Collagen, on improving osteoarthritis-related symptoms: a randomized, double-blind, placebo-controlled trial.

Osteoarthritis (OA) is a significant source of pain and disability. Current medical and surgical treatments can be costly and have serious side effects. The aim of this randomized, double-blind, placebo-controlled trial was to investigate the tolerability and efficacy of BioCell Collagen (BCC), a low molecular weight dietary supplement consisting of hydrolyzed chicken sternal cartilage extract, in the treatment of OA symptoms. Patients (n = 80) in the study had physician-verified evidence of progressive OA in their hip and/or knee joint. Joint pain had been present for 3 months or longer at enrollment, and pain levels were 4 or higher at baseline as assessed by Physician Global Assessment scores. Subjects were divided into two groups and administered either 2 g of BCC or placebo for 70 days. Other outcome measurements included visual analogue scale (VAS) for pain and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores taken on days 1, 35, and 70. The tolerability profile of the treatment group was comparable to that of the placebo. Intent-to-treat analysis showed that the treatment group, as compared to placebo, had a significant reduction of VAS pain on day 70 (p < 0.001) and of WOMAC scores on both days 35 (p = 0.017) and 70 (p < 0.001). The BCC group experienced a significant improvement in physical activities compared to the placebo group on days 35 (p = 0.007) and 70 (p < 0.001). BCC was well tolerated and found to be effective in managing OA-associated symptoms over the study period, thereby improving patient's activities of daily living. BCC can be considered a potential complement to current OA therapies.

Efficacy and tolerability assessment of a topical formulation containing copper sulfate and hypericum perforatum on patients with herpes skin lesions: a comparative, randomized controlled trial.

BACKGROUND: Topical Acyclovir has moderate efficacy on recurrent HSV symptoms, requiring repeat applications for several days. Topical Dynamiclear, which requires only a single dose application, may provide a more effective and convenient treatment option for symptomatic management of HSV. OBJECTIVES: The study assessed the comparative efficacy and tolerability of a single use, topical formulation containing copper sulfate pentahydrate and Hypericum perforatum that is marketed as Dynamiclear™ to a topical 5% Acyclovir cream standard preparation and use. METHODS: A prospective, randomized, multi-centered, comparative, open-label clinical study was conducted. A total of 149 participants between 18 and 55 years of age with active HSV-1 and HSV-2 lesions were recruited for the 14-day clinical trial. Participants were randomized into two groups: A (n=61), those receiving the Dynamiclear formulation, and B (n=59), those receiving 5% Acyclovir. Efficacy parameters were assessed via physical examination at baseline (day 1), day 2, 3, 8, and 14. Laboratory safety tests were conducted at baseline and on day 14. RESULTS: Use of the Dynamiclear formulation was found to have no significant adverse effects and was well tolerated by participants. All hematological and biochemical markers were within normal range for the Dynamiclear group. Statistically, odds for being affected by burning and stinging sensation were 1.9 times greater in the Acyclovir group in comparison to the Dynamiclear group. Similarly, the odds of being affected by symptoms of acute pain, erythema and vesiculation were 1.8, 2.4, and 4.4 times higher in the Acyclovir group in comparison to the Dynamiclear group. CONCLUSIONS: The Dynamiclear formulation was well tolerated, and efficacy was demonstrated in a number of measured parameters, which are helpful in the symptomatic management of HSV-1 and HSV-2 lesions in adult patients. Remarkably, the effects seen from this product came from a single application.

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.

Safety evaluation of a proprietary food-grade, dried fermentate preparation of Saccharomyces cerevisiae.

A safety evaluation was performed for EpiCor, a product produced by a proprietary fermentation process using Saccharomyces cerevisiae. Studies included the following assays: bacterial reverse mutation, mouse lymphoma cell mutagenicity, mitogenicity assay in human peripheral lymphocytes, and a cytochrome P450 ([CYP] CYP1A2 and CYP3A4) induction assessment as well as 14-day acute, 90-day subchronic, and 1-year chronic oral toxicity studies in rats. No evidence of genotoxicity or mitogenicity was seen in any of the in vitro or in vivo studies. The CYP assessment showed no interactions or inductions. No toxic clinical symptoms or histopathological lesions were observed in the acute, subchronic, or chronic oral toxicity studies in the rat. Results of the studies performed indicate that EpiCor does not possess genotoxic activity and has a low order of toxicity that is well tolerated when administered orally. The no observable adverse effect level (NOAEL) was 1500 mg/kg body weight (bw)/d for the 90-day study and 800 mg/kg bw/d for the 1 year study, for the highest doses tested.

Evaluation of the safety of the dietary antioxidant ergothioneine using the bacterial reverse mutation assay.

The dietary antioxidant L-(+)-ergothioneine was tested for its potential mutagenic activity using the bacterial reverse mutation assay. The experiments were carried out using histidine-requiring auxotrophic strains of Salmonella typhimurium (Salmonella typhimurium TA98, TA100, TA1535 and TA1537), and the tryptophan-requiring auxotrophic strain of Escherichia coli (Escherichia coli WP2 uvrA) in the presence and absence of a post-mitochondrial supernatant (S9) prepared from livers of phenobarbital/ß-naphthoflavone-induced rats. The revertant colony numbers of vehicle control plates with and without S9 Mix were within the corresponding historical control data ranges. The reference mutagen treatments (positive controls) showed the expected, biologically relevant increases in induced revertant colonies in all experimental phases in all tester strains. No biologically relevant increases were observed in revertant colony numbers of any of the five test strains following treatment with L-(+)-ergothioneine at any concentration level, either in the presence or absence of metabolic activation (S9 Mix) in the performed experiments. On the basis of the data reported, it can be concluded that L-(+)-ergothioneine did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Thus L-(+)-ergothioneine has no mutagenic activity on the applied bacteria tester strains under the test conditions used in this study. Research is continuing to define the role of L-(+)-ergothioneine in disease pathophysiology. Further studies on its safety are suggested.

Safety evaluation of an açai-fortified fruit and berry functional juice beverage (MonaVie Active(®)).

The safety of an açai (Euterpe oleracea Mart.) pulp enriched fruit and berry juice, MonaVie Active®, fortified with the functional ingredient, glucosamine, was studied. The beverage was found not to be mutagenic, clastogenic, cytotoxic, or genotoxic, as determined by the bacterial reverse mutation assay, chromosomal aberration assay, mouse micronucleus assay, and mammalian cell gene mutation (L5178Y) assay. The single dose LD50 based on a 14-day acute oral toxicity study is greater than 20,000 mg/kg bw, the highest dose tested. In a repeat dose 90-day oral subchronic toxicity study by gavage, 220 animals were randomly assigned to a control group, an untreated group, or one of three experimental groups (10, 20 and 40 g/kg bw). No treatment-related significant changes in body weight, food and water consumption, ophthalmology, organ weights, urinanalysis, hematological and clinical chemistry, or gross pathology, were observed in surviving animals compared to the control groups. Three animals died midway through the observation period (male, 20 g/kg bw/day; male 40 g/kg bw/day; and, female, 10 g/kg bw/day). These animals died without preceding clinical symptoms, histopathological lesions, or evidence of injury to tissue or organs except for signs of suffocation/aspiration congestion, which was concluded to be due to problems with the gavage administration of the fluid test article, and not due to the test article itself. The NOEAL was determined to be 40 g/kg bw/day for male and female rats, which was the highest dose tested. Phylloquinone (vitamin K1) content averaged 21.7 µg/100 g, comparable to amounts found in iceberg lettuce. In conclusion, the results provide additional experimental evidence that MonaVie Active® juice is non-toxic.

Similar structural basis for membrane localization and protein priming by an RNA-dependent RNA polymerase.

Protein primers are used to initiate genomic synthesis of several RNA and DNA viruses, although the structural details of the primer-polymerase interactions are not yet known. Poliovirus polymerase binds with high affinity to the membrane-bound viral protein 3AB but uridylylates only the smaller peptide 3B in vitro. Mutational analysis of the polymerase identified four surface residues on the three-dimensional structure of poliovirus polymerase whose wild-type identity is required for 3AB binding. These mutants also decreased 3B uridylylation, arguing that the binding sites for the membrane tether and the protein primer overlap. Mutation of flanking residues between the 3AB binding site and the polymerase active site specifically decreased 3B uridylylation, likely affecting steps subsequent to binding. The physical overlap of sites for protein priming and membrane association should facilitate replication initiation in the membrane-associated complex.