Safety assessment of lutein and zeaxanthin (Lutemax™ 2020): Subchronic toxicity and mutagenicity studies

Lutein and zeaxanthin, naturally occurring carotenoids, have shown to reduce the risk of cataracts and age-related macular degeneration. Lutemax™ 2020 is a lutein and zeaxanthin (including meso-isomer) enriched product obtained from Marigold flowers (Tagetes erecta L). The objective of the present study was to investigate adverse effects, if any, of Lutemax 2020™ in acute and subchronic toxicity, and mutagenicity studies. In acute toxicity study in rats no lethality was noted at 2000 mg Lutemax 2020™/kg body weight (bw). In the subchronic study, Wistar rats (10/sex/group) were administered (gavage) lutein/zeaxanthin concentrate at dose levels of 0, 4, 40 and 400 mg/kg bw/day for 90-days. Compared with the control group, administration of lutein/zeaxanthin concentrate did not result in any toxicologically significant treatment-related changes in clinical observations, ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. No toxicologically relevant findings were noted in urinalysis, hematology or clinical biochemistry parameters at the end of the treatment or recovery period. Terminal necropsy did not reveal any treatment-related gross or histopathology findings. The results of mutagenicity testing in Salmonella typhimurium did not reveal any genotoxicity. The no observed-adverse-effect level (NOAEL) for lutein/zeaxanthin concentrate was determined as 400 mg/kg bw/day, the highest dose tested.     

Subchronic oral toxicity of 4-chloro-alpha, alpha, alpha-trifluorotoluene in Sprague-Dawley rats

The subchronic oral toxicity of 4-chloro-alpha, alpha, alpha-trifluorotoluene (CTT) was assessed in Sprague-Dawley rats. Four groups of six male and six female rats were treated daily for 28 days, by gavage, with doses of 0, 10, 100 and 1000 mg CTT/kg body weight using olive oil as a vehicle. No clinical signs were observed, other than salivation in the high-dose group in the last week. The males of this group showed a significant decrease in body-weight gain without a concurrent decrease in food consumption. In males, there were significant dose-dependent increases in blood cholesterol and triglycerides, suggestive of alterations in lipid metabolism. The females showed only a small dose-related increase in serum lactate dehydrogenase. Specific histological alterations were found in the males given 1000 mg/kg/day, namely hyaline droplet nephrosis, along with a significant increase in relative kidney weight, and an increase in lipid vacuoles in the adrenal cortex. Slight nephrosis was also observed in males given 100 mg/kg. Both male and female rats showed a significant increase in relative liver weight at a dose of 1000 mg CTT/kg. CTT appears to have a low subchronic oral toxicity. Neither pathological nor biochemical alterations were found at 10 mg/kg body weight/day and this can be defined as the no-observable-effect level (NOEL).     

Safety assessment of a solid lipid curcumin particle preparation: Acute and subchronic toxicity studies

Curcumin, a polyphenol, is obtained from turmeric, the ground rhizomes of Curcuma longa L. Extensive research over the past half century has revealed several health benefits of curcumin. The objective of the present study was to investigate potential adverse effects, if any, of a novel solid lipid curcumin particle (SLCP) preparation in rats following acute and subchronic administration. The oral LD₅₀ of the preparation in rats as well as in mice was found to be greater than 2000 mg/kg body weight (bw). In the subchronic toxicity study, Wistar rats (10/sex/group) were administered via oral gavage 0 (control), 180, 360, and 720 mg/kg bw/day of SLCP preparation for 90 days. Administration of the curcumin preparation did not result in any toxicologically significant treatment-related changes in clinical (including behavioral) observations, ophthalmic examinations, body weights, body weight gains, feed consumption, and organ weights. No adverse effects of the curcumin preparation were noted on the hematology, serum chemistry parameters, and urinalysis. Terminal necropsy did not reveal any treatment-related gross or histopathology findings. Based on the results of this study, the No Observed-Adverse-Effect Level (NOAEL) for this standardized novel curcumin preparation was determined as 720 mg/kg bw/day, the highest dose tested.     

Subchronic toxicity studies of the aqueous extract of Aristolochiae fructus in Sprague-Dawley rats

The subchronic toxicity of Aristolochiae fructus containing aristolochic acids (AAs), a natural component in the Aristolochiaceae family, was investigated. The A. fructus was daily administered by gavage to male and female rats for 90 d at dose levels of 21.35, 213.5, and 2135 mg/kg (equivalent to 0.05, 0.5, and 5 mg/kg as AAs, respectively). During the test period, clinical signs, mortality, body weights, food and water consumption, hematology, serum biochemistry, organ weights, and histopathology were examined. Significant decreases in body weight gain were noted in the high-dose group receiving both the aqueous extract of A. fructus and AAs. Decreases in food consumption were noted beginning at 50 d and did not recover in the high-dose group of aqueous extract of A. fructus and AAs. Irrespective of dose, water consumption was not affected. There was no mortality or adverse clinical signs, hematology, or serum biochemistry in the treatment groups versus control. Nephrotoxicity and hyperplasia of epithelial cells in the forestomach were observed in rats receiving the highest dose of aqueous extract of A. fructus and at doses of >or= 0.5 mg/kg/day AAs. For both genders, the no-observed-adverse-effect level (NOAEL) for A. fructus based on this subchronic study in rats was considered to be 21.3 mg/kg/d.     

Ninety-day oral toxicity study of lycopene from Blakeslea trispora in rats

Lycopene, as a suspension in sunflower oil (20% w/w), was tested for subchronic toxicity by administration at dietary concentrations of 0, 0.25, 0.50, and 1.0% to groups of 20 male and 20 female Wistar rats for a period of 90 days. The lycopene examined in this study was derived from a fungal biomass (Blakeslea trispora). Lycopene intake was calculated to be 0, 145, 291, and 586mg/kg body weight/day in control through high-dose males and 0, 156, 312, and 616mg/kg body weight/day in control through high-dose females. The results from this study do not provide any evidence of toxicity of lycopene at dietary levels up to 1.0% as demonstrated by the findings of clinical observations, neurobehavioral observations, motor activity assessment, body weight and food consumption measurements, ophthalmoscopic examinations, hematology, clinical chemistry, urinalysis, organ weights, gross pathology, or histopathology. The No-Observed-Effect Level (NOEL) was 1.0% in the diet, the highest dietary concentration tested.     

Safety assessment of heat-sterilized green tea catechin preparation: A 6-month repeat-dose study in rats

Evidence suggests that the purported health benefits associated with green tea consumption are related to tea catechins. In the present study, potential adverse effects of a standardized heat-sterilized green tea catechin (GTC-H) preparation was investigated following gavage administration to rats at doses of 0, 120, 400, 1200 mg/kg/day for 6 months. A decaffeinated high-dose group (1200 mg/kg/day) (GTC–HDC), was included for comparison. A possibly test article-related clinical finding of intermittent increased activity was noted in the 400 and 1200 mg/kg/day GTC-H groups, but was not considered to be adverse. Lower body weight gains without any decrease in food consumption were noted in the high-dose (1200 mg/kg/day)-treated GTC-H and GTC–HDC females. In the high-dose male GTC-H group, a lower total motor activity count for the 60-min session was noted prior to dosing at the study week 25 evaluations compared to the control group. Similar changes were not observed in the GTC–HDC group. Based on the results of this study, the no-observed-adverse-effect level (NOAEL) for GTC-H was 1200 mg/kg/day for males, the highest dose tested, and 400 mg/kg/day for females based on reduced body weight gains. The NOAEL for GTC–HDC was 1200 mg/kg/day for males and could not be determined in females.     

Acute and subchronic mammalian toxicity of naphthenic acids from oil sands tailings.

Naphthenic acids are the most significant environmental contaminants resulting from petroleum extraction from oil sands deposits. In this study, a mixture of naphthenic acids isolated from Athabasca oil sands (AOS) tailings pond water was used in acute and subchronic toxicity tests with rodents, in order to assess potential risks posed to terrestrial wildlife. Dosages were chosen to bracket worst-case environmental exposure scenarios. In acute tests, adult female Wistar rats were given single po dosages of naphthenic acids at either 3, 30, or 300 mg per kg body weight (mg/kg), while adult male rats received 300 mg/kg. Food consumption was temporarily suppressed in the high-dose groups of both sexes. Following euthanasia 14 days later, histopathology revealed a significant incidence of pericholangitis in the high-dose group of both sexes, suggesting hepatotoxicity as an acute effect. Other histological lesions included brain hemorrhage in high-dose males, and cardiac periarteriolar necrosis and fibrosis in female rats. In subchronic tests, naphthenic acids were po administered to female Wistar rats at 0.6, 6, or 60 mg/kg, 5 days per week for 90 days. Results again suggested the liver as a potential target organ. The relative liver weight in the high-dose group was 35% higher than in controls. Biochemical analysis revealed elevated blood amylase (30% above controls) and hypocholesterolemia (43% below controls) in high-dose rats. Excessive hepatic glycogen accumulation was observed in 42% of animals in this group. These results indicate that, under worst-case exposure conditions, acute toxicity is unlikely in wild mammals exposed to naphthenic acids in AOS tailings pond water, but repeated exposure may have adverse health effects.     

Subchronic toxicity and mutagenicity/genotoxicity studies of Irvingia gabonensis extract (IGOB131)

African Bush Mango from Irvingia gabonensis is a West African culinary fruit and the mucilage from this fruit seed is used to make traditional soups and sauces. Extract from the kernel (IGOB131) has been claimed for its health benefits. In the present investigations, potential adverse effects, if any, of IGOB131 were investigated in dose–response 90-day study and genotoxicity studies. In the subchronic study, Sprague Dawley rats (20/sex/group) were gavaged with I. gabonensis extract (IGOB131) at dose levels of 0, 100, 1000 and 2500 mg/kg body weight (bw)/day for 90-days. No treatment-related changes in clinical signs, functional observations, mortality, ophthalmologic observations, body weights, body weight gain or feed consumption were noted. Similarly, hematological, clinical chemistry, urine analysis parameters, and organ weights did not reveal any toxicologically significant treatment-related changes. No treatment-related macroscopic and microscopic abnormalities were noted at the end of treatment period. The mutagenicity as evaluated by Ames assay, in vitro and in vivo chromosomal aberration test and in vivo micronucleus assay did not reveal any genotoxicity of IGOB131. The results of subchronic toxicity study suggest the no-observed-adverse-effect level (NOAEL) for I. gabonensis extract (IGOB131) as ?2500 mg/kg bw/day, the highest dose tested.     

A subchronic oral toxicity study of almond skins in rats

Almond skins have been suggested to have some potential benefits. To investigate the subchronic toxicity of almond skins, a 90-feeding study was conducted in rats. Sprague–Dawley rats were randomly divided into four groups (20 rats/sex/group) and received a diet containing 0%, 2.5%, 5.0% and 10% (w/w) almond skins for 90 days. Daily clinical observations and weekly measurement of body weights and food consumption were conducted. Ophthalmic examinations were performed at pre-test and termination. Blood samples were obtained on day 46 and day 91 for the measurement of hematology, coagulation and clinical chemistry parameters. Urine samples were collected on day 91 for urinalysis. Animals were euthanized for necropsy. Selected organs were weighted and recorded. Histological examination was performed on all tissues from animals in the control and high-dose groups. No mortality, body weight, ophthalmic abnormalities or treatment-related findings in clinical observations, hematology, coagulation, urinalysis parameters, macroscopic or microscopic examinations were observed. Differences between treated and control groups in weight gain, food consumption, clinical chemistry, and organ weight were not considered treatment-related. The no-observed-adverse-effect-level (NOAEL) for almond skins was considered to be 10% (w/w) for both genders (females, 9.7 g/kg body weight/day; males, 8.2 g/kg body weight/day).     

Subchronic toxicity and genotoxicity of diiodomethyl-p-tolylsulfone (DIMPTS) in laboratory animals

These studies were conducted to determine subchronic toxicity and genotoxicity of the biocide diiodomethyl-p-tolysulfone (DIMPTS) in rats and dogs. Male and female Sprague-Dawley rats and Beagle dogs were administered DIMPTS for 90-days via the diet at 0, 5, 20, and 80 mg/kg/day to rats and via capsules at 0, 2, 10, and 60 mg/kg/day to dogs. In rats, the only treatment-related finding was squamous metaplasia of the salivary gland duct in the 80 mg/kg/day group. In dogs, female body weights in the high-dose group were significantly lower than controls. Altered clinical pathology parameters were considered secondary to inflammatory changes observed in some of the dogs. Treatment-related alterations were found in the thyroid glands, salivary glands, GI-tract in the mid- and/or high-dose groups. DIMPTS was negative in the four in vitro and one in vivo genotoxicity assays. The toxicological effects noted in the two mammalian species are consistent with the principal toxic effects of iodine, and are proposed to arise from release of iodide from the DIMPTS molecule with toxic sequelae.     

Toxicological assessment of a particulate yeast (1,3/1,6)-beta-D-glucan in rats.

This study investigates the toxicity of WGP 3-6, a yeast-derived beta-glucan ingredient, during single-dose acute and sub-chronic toxicity studies in rats. For the acute study, Fisher-344 rats were administered WGP 3-6 via gavage at a dose of 2000 mg/kg body weight, and any evidence of toxicity was monitored over a 14-day period. WGP 3-6 was well tolerated, indicating that the LD(50) value is greater than 2000 mg/kg body weight. For the sub-chronic study, Fisher-344 rats (10/sex/group) were randomly allocated to receive daily gavage treatment with WGP 3-6 at doses of 0, 2, 33.3, or 100 mg/kg body weight. Control and high-dose satellite recovery groups of each sex also were included. Full toxicological monitoring and endpoint investigations were performed throughout and upon completion of the study. No negative effects on animal weights or food consumption attributable to WGP 3-6 were evident at any dose. In addition, no mortality, clinical pathology, functional/behavioral, microscopic, or gross observations indicating toxicity were observed. Sporadic changes in some biochemical and hematological parameters were observed; however, since the effects were within the physiological ranges in historical controls, were not dose-responsive, or were not observed in both sexes, they were determined to be of no toxicological significance. In conclusion, no adverse or toxic effects were observed after subchronic oral administration of 2, 33.3, or 100mg/kg body weight/day of WGP 3-6 in Fisher-344 rats, and therefore, a no observed adverse effect level (NOAEL) of 100 mg/kg body weight/day, the highest dose tested, was determined.     

Acute and subchronic toxicity studies of pyrroloquinoline quinone (PQQ) disodium salt (BioPQQ™) in rats

The potential use of pyrroloquinoline quinone disodium salt (BioPQQ™), as a supplemental food ingredient, was evaluated in a range of oral toxicity studies in rats including an acute study, a 14-day preliminary and a 28-day repeated-dose study, and a 13-week subchronic study. The median lethal dose of BioPQQ™ was shown to be 1000–2000 mg/kg body weight (bw) in male and 500–1000 mg/kg bw in female rats. In the 14-day study, high doses of BioPQQ™ resulted in increases in relative kidney weights with associated histopathology in female rats only, while a follow-up 28-day study in female animals resulted in increases in urinary protein and crystals. These findings were reversible, and resolved during the recovery period. In the 13-week study, a number of clinical chemistry findings and histopathological changes were noted, which were deemed to be of no toxicological significance, as the levels were within the historical control range, were not dose-dependent, occurred at a similar frequency in control groups, or only occurred in the control group. Based on these findings, a no-observed-adverse-effect level of 100 mg/kg bw/day was determined for BioPQQ™ in rats, the highest dose tested in the 13-week study.     

Two-year drinking-water study of formaldehyde in rats

Formaldehyde was administered in the drinking-water to groups of 70 male and 70 female Wistar rats for up to 24 months. Survivors of subgroups of ten rats/sex/group each were killed after 12 or 18 months. The mean formaldehyde doses administered were 0, 1.2, 15 or 82 mg/kg body weight/day for males, and 0, 1.8, 21 or 109 mg/kg/day for females. There were no adverse effects on general health, survival or haematological or clinical chemistry parameters. Body weight and food intake were decreased in the high-dose group. Liquid intake was decreased by 40% in the high-dose group in both sexes in comparison with the controls. There was a slight temporary increase in the density of urine, whereas there was a tendency towards lower urine production in the high-dose group. The relative kidney weights were increased in the high-dose females. Gross examination at autopsy revealed a raised and thickened limiting ridge of the forestomach in most high-dose rats. In addition, several rats in the high-dose group showed irregular mucosal thickenings in the fore- and/or glandular stomach. Treatment-related histopathological gastric changes seen in most of the animals of the high-dose group included papillary epithelial hyperplasia frequently accompanied by hyperkeratosis and focal ulceration in the forestomach and focal chronic atrophic gastritis, occasionally accompanied by ulceration and/or glandular hyperplasia, in the glandular stomach. A higher incidence and/or degree of renal papillary necrosis occurred in the high-dose rats. From this study it appeared that the 'no-observed-adverse-effect level' of formaldehyde was 15 and 21 mg/kg body weight/day for male and female rats, respectively. Oral administration of formaldehyde at doses of 82 and 109 mg/kg/day to male and female rats, respectively, caused severe damage to the gastric mucosa but did not result in gastric tumours or tumours at other sites. The study did not provide any evidence of carcinogenicity of formaldehyde after oral administration.     

Subchronic and developmental toxicity studies in rats with Ac-Di-Sol croscarmellose sodium

Studies were conducted to evaluate the subchronic and developmental toxicity of Ac-Di-Sol (croscarmellose sodium). In the subchronic study, groups of Sprague-Dawley rats (20/sex/group) received 0 (control), 10000, or 50000 ppm Ac-Di-Sol in the diet for 90 consecutive days (equivalent to 757 and 893 mg/kg/day for males and females fed 10000 ppm, respectively, and to 3922 and 4721 mg/kg/day for males and females fed 50000 ppm, respectively). No mortality, clinical signs of toxicity, or adverse toxicological effects on hematology or serum chemistry parameters, feed consumption, or ophthalmologic examinations were noted in any treatment group. Body weight gain was depressed in high-dose males during the final 3 weeks. The only treatment-related histological lesion noted was moderate renal mineralization at the corticomedullary junction in one high-dose female. This lesion was not considered a specific effect of Ac-Di-Sol, but rather a secondary effect resulting from a potential increase in urinary pH and renal excretion of sodium due to the high intake of sodium associated with Ac-Di-Sol. In the developmental toxicity study, groups of pregnant Sprague-Dawley rats (25/group) received 0 (control), 10000, or 50000 ppm Ac-Di-Sol in the diet on gestational days 6 to 15. No evidence of maternal, fetal, or embryo toxicity was noted. The no-observed-adverse-effect level (NOAEL) for Ac-Di-Sol in both studies exceeds 50000 ppm in the diet, which represents doses of 3922 and 4712 mg/kg/day, for males and females, respectively. The results of these studies demonstrate the low subchronic oral toxicity and developmental toxicity of Ac-Di-Sol, and support the safe use of Ac-Di-Sol in oral applications such as pharmaceuticals, dietary supplements, and sweetener tablets.     

Results of a 90-day safety assessment study in mice fed a glucan produced by Agrobacterium sp. ZX09

Salecan is a novel water-soluble glucan produced by Agrobacterium sp. ZX09. It has potential application as a food additive with a unique chemical composition and excellent physicochemical properties. The objective of this study was to investigate the acute and subchronic toxicity of Salecan. The oral LD50 of Salecan in ICR mice was greater than 3000 mg/kg body weight. In the subchronic study, ICR mice (10/sex/group) were fed diets containing 0%, 1.0%, 2.5% and 5.0% of Salecan (weight/weight) for 13 weeks. Based on the results from the subchronic study, the overall health, body weight gain, food consumption and clinical pathology parameters were comparable between the groups feed Salecan and the control. No dose-related effects were observed in the treated animals. The only exception was the observation that blood glucose in female mice fed Salecan was lower than in the control group. In addition, the fecal matter from Salecan fed mice exhibited increased water content versus the control animals. The no observed adverse effect level (NOAEL) of 14478 mg/kg body weight/day was determined. The results from this study support the conclusion that Salecan is non-toxic at the levels tested and does not pose a risk to human health when used in food.     

A 90-day oral toxicity study of beta-carotene derived from Blakeslea trispora, a natural food colorant, in F344 rats.

A subchronic oral toxicity study of beta-carotene derived from Blakeslea trispora, a natural food colorant, was performed with groups of 10 male and 10 female F344 rats fed the agent at dietary levels of 0%, 0.2%, 1.0% and 5.0% for 90 days. There were no treatment-related adverse effects with regard to body weight, food and water consumption, urinalysis, ophthalmology, hematology, serum biochemistry, and organ weight data. On clinical observation, red coloring of fur was noted in both sexes of the 1.0% and 5.0% group rats, with red feces observed in all treated group animals, and necropsy revealed all rats of the treated groups to have reddish coloration of the contents of the gastro-intestinal tract, due to the pigmentation and thus lacking toxicological significance. On histopathological examination, sporadic spontaneous lesions known to occur in this strain of rats were the only findings, with no specific relation to the test substance. Thus, the no-observed-adverse-effect-level (NOAEL) was judged to be a dietary level of at least 5.0% (3127 mg/kg body weight/day for males, 3362 mg/kg body weight/day for females) for beta-carotene derived from B. trispora under the present experimental conditions.     

Genotoxicity, acute and subchronic toxicity studies in rats of a rooster comb extract rich in sodium hyaluronate

The toxicity of a rooster comb extract (IB0004) that contains mainly sodium hyaluronate was assessed in acute and subchronic studies and in a bacterial reverse mutation assay. In a single dose acute study, male and female rats were administered 2000 mg/kg body weight (bw) of the product and observed for 14 days. No mortality was recorded, thus it was considered that the minimum lethal dose for rats by oral route was greater than 2000 mg/kg bw. A 90-day subchronic study (5, 55 and 600 mg/kg bw/day, oral gavage) with 50 male and 50 female Wistar-Hannover rats produced no significant adverse effects on food consumption, body weight, mortality, clinical biochemistry, hematology, gross pathology, and histopathology. Although some differences were observed between the treated and control animals in body weight gain (%) and some hematological parameters, these changes were generally minor in nature and, are considered to be of no toxicological significance. The no-observable-adverse-effects level was established at 600 mg/kg bw/day. There was no evidence of mutagenic activity in Salmonella typhimurium TA98, TA100, TA1535 and TA1537 or in Escherichia coli WP2 uvra pkM101. In conclusion, the results from these safety studies support the safety of rooster comb extract IB0004 in food.     

Acute, subchronic and genotoxicity studies conducted with Oligonol, an oligomerized polyphenol formulated from lychee and green tea extracts

Oligonol is a phenolic product derived from lychee fruit extract and green tea extract, containing catechin-type monomers and oligomers of proanthocyanidins, produced by a manufacturing process which converts polyphenol polymers into oligomers. The safety of Oligonol was assessed in acute and subchronic studies and genotoxicity assays. In a single dose acute study of Oligonol, male and female rats were administered 2000mg/kg body weight (bw) Oligonol in water by gavage. Oligonol caused no adverse effects and body weight gain and food consumption were within normal range, thus the LD(50) of Oligonol was determined to be greater than 2000mg/kg. A 90 day subchronic study (100, 300 and 1000mg/kgbw/day, oral gavage) in male and female rats reported no significant adverse effects in food consumption, body weight, mortality, clinical chemistry, haematology, gross pathology and histopathology. Similarly, no adverse effects were observed in mice fed diets providing 2, 20 or 200mg/kgbw Oligonol or 200mg/kgbw lychee polyphenol for 90 days. Oligonol did not show any potential to induce gene mutations in reverse mutation tests using Salmonella typhimurium TA98, TA100, TA1535, TA1537 and Escherichia coli WP2uvrA strains. Oligonol did not induce chromosomal aberrations in cultured Chinese hamster lung cells, but it showed increased polyploidy. In a micronucleus assay in mice, Oligonol did not induce any micronuclei or suppress bone marrow, indicating it does not cause chromosome aberrations. The results from these safety studies and previous reports support the safety of Oligonol for human consumption.     

Prechronic Toxicity Studies on 2-Ethylhexanol in F334 Rats and B6C3F1 Mice

Data on the subchronic toxicity of 2-ethylhexanol (2EH) wererequired to establish the dose vehicle and dose levels for oncogenicitystudies. In preliminary studies 2EH was given subacutely (11days) to male and female Fischer 344 rats and B6C3F1 mice asan aqueous emulsion by oral gavage (0, 100, 330, 1000, and 1500mg/kg/day). Clinical observations were made, body weights, foodconsumption, clinical chemistries, hematologies, and selectedorgan weights were measured, and gross and micropathologieswere performed. Target organs were the central nervous system,liver, forestomach, spleen, thymus, and kidney in rats and thecentral nervous system, liver, and forestomach in mice. 2EHwas then administered by oral gavage to male and female F344rats and B6C3F1 mice as an aqueous emulsion (0, 25, 125, 250,and 500 mg/kg/day) for 13 weeks. At 500 mg/kg/day in the ratthere was reduced body weight gain (6% male, 7% female), increasedrelative liver (29% male, 15% female), kidney (16% male, 6%female), stomach (11% male, 16% female), and testes (6%) weights,and moderate gross and microscopic changes in the liver andforestomach. There were no behavioral effects or effects onthe spleen or thymus. A no-effect level for target organ effectsin the rat was 125 mg of 2EH/kg/day. At 500 mg of 2EH/kg/dayin the mouse the only effects were increased relative stomachweights in males (13%) and a low incidence of gross and microscopicfindings in the forestomach (male and female) and liver (female).A no-effect level for target organ effects in the mouse was125 mg of 2EH/kg/day. 2EH was a peroxisome proliferator in therat but not in the mouse at subchronic dose levels of 500 mg/kg/day.Dose levels in oncogenicity studies were set at 50 mg/kg/dayfor the absence of treatment-related effects in rats and mice,and 500 and 750 mg/kg/day, respectively, in rats and mice ashigh doses producing minimal toxicity without altering the lifespan.     

Safety evaluation of an enzymatically-synthesized glycogen (ESG)

An enzymatically-synthesized glycogen (ESG), intended for use as a food ingredient, was investigated for potential toxicity. ESG is synthesized in vitro from short-chain amylose by the co-operative action of branching enzyme and amylomaltase. In an acute toxicity study, oral administration of ESG to Sprague–Dawley rats at a dose of 2000 mg/kg body weight did not result in any signs of toxicity. ESG did not exhibit mutagenic activity in an in vitro bacterial reverse mutation assay. In a subchronic toxicity study, increased cecal weights noted in the mid- (10%) and high-dose (30%) animals are common findings in rodents fed excess amounts of carbohydrates that increase osmotic value of the cecal contents, and thus were considered a physiological rather than toxicological response. The hematological and histopathological effects observed in the high-dose groups were of no toxicological concern as they were secondary to the physiological responses resulting from the high carbohydrate levels in the test diets. The no-observed-adverse-effect level for ESG in rats was therefore established to be 30% in the diet (equivalent to approximately 18 and 21 g/kg body weight/day for male and female rats, respectively). These results support the safety of ESG as a food ingredient for human consumption.