Effects of dietary diacylglycerol oil on embryo/fetal development in rats

Diacylglycerol (DAG) oil is an edible oil with similar taste and usability characteristics as conventional edible oil. Recent studies suggest that use of DAG oil may be helpful in the prevention and management of obesity. This study evaluated the potential maternal and fetal effects of DAG oil, following exposure to pregnant rats, during the critical period of major organogenesis. DAG oil was administered via gavage to four groups of mated female Crl:CD(SD)IGS BR rats (25/group) once daily from gestation day 6 through 17, at dose levels of 0, 1.25, 2.5 or 5.0 ml/kg/day (0, 1160, 2320 and 4630 mg/kg/day) with total volume made to 5 ml/kg/day with triacylglycerol (corn) oil. No mortality or treatment-related clinical or internal findings were noted in any of the groups. Compared to animals in control group, mean maternal body weights, body weight gains, net body weights, net body weight gains, gravid uterine weights, and food consumption were not affected by DAG oil administration. Similarly, intrauterine growth and survival were not affected by DAG oil administration. No DAG oil-related fetal malformations or developmental variations were noted. A maternal maximum tolerated dose for DAG oil was not achieved in this study. Based on the results of this study, a dose level of 5.0 ml/kg (4630 mg/kg/day) was considered as no-observed-adverse-effect level (NOAEL) for both maternal and developmental toxicity.     

Safety assessment of pomegranate fruit extract: Acute and subchronic toxicity studies

Pomegranate (Punica granatum L.) fruit is widely consumed as fresh fruit and juice. Because of its potential for health benefits, pomegranate fruit extracts have been commonly marketed as dietary supplements in recent years. The objective of the present study was to investigate potential adverse effects, if any, of a standardized pomegranate fruit extract in rats following subchronic administration. The extract was standardized to 30% punicalagins, the active anomeric ellagitannins responsible for over 50% of the antioxidant potential of the juice. The oral LD(50) of the extract in rats and mice was found to be greater than 5 g/kg body weight. The intraperitoneal LD(50) in rats and mice was determined as 217 and 187 mg/kg body weight, respectively. In the subchronic study, Wistar strain rats (10/sex/group) were administered via gavage 0 (control), 60, 240 and 600 mg/kg body weight/day of the extract for 90 days. Two additional groups received 0 and 600 mg/kg/day of the extract for 90 days, followed by a 28 day recovery phase. Compared to the control group, administration of the extract did not result in any toxicologically significant treatment-related changes in clinical observations, ophthalmic examinations, body weights, body weight gains, feed consumption, clinical pathology evaluations and organ weights. The hematology and serum chemistry parameters that showed statistical significant changes compared to control group were within the normal laboratory limits and were considered as biological variations and not the toxic effect of the extract. 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 pomegranate fruit extract was determined as 600 mg/kg body weight/day, the highest dose tested.     

Safety assessment of Cissus quadrangularis extract (CQR-300): Subchronic toxicity and mutagenicity studies

Cissus quadrangularis has been used for centuries for therapeutic and culinary purposes. Extract from this plant (CQR-300) has been claimed for its health benefits. The objective of present investigation was to delineate adverse effects, if any, of CQR-300 in subchronic toxicity, and gentotoxicity studies. In the subchronic study, Sprague Dawley rats (20/sex/group) were administered (gavage) C. quadrangularis extract (CQR-300) at dose levels of 0, 100, 1000, and 2500 mg/kg body weight (bw)/day for 90 days. No treatment related clinical signs of toxicity, mortality or changes in body weights, body weight gain or food consumption were noted. Functional observation tests and ophthalmological examination did not reveal any changes. No toxicologically significant treatment related changes in hematological, clinical chemistry, urine analysis parameters, and organ weights were noted. No treatment related macroscopic and microscopic abnormalities were noted at the end of treatment period. The results of mutagenicity studies as evaluated by Ames assay, in vitro chromosomal aberration and in vivo micronucleus assay did not reveal any genotoxicity of CQR-300. Based on the subchronic study, the no-observed-adverse-effect level (NOAEL) for C. quadrangularis extract (CQR-300) determined as 2500 mg/kg bw/day, the highest dose tested.     

Safety assessment of dietary diacylglycerol oil: A two-generation reproductive toxicity study in rats

Diacylglycerol (DAG) oil is a novel edible oil with similar taste and usability characteristics as conventional edible oils. Recent studies suggest that DAG oil may be helpful in the prevention and management of obesity. The objective of the present two-generation study was to evaluate potential adverse effects of DAG oil on reproductive processes. DAG oil was administered via gavage to rats (30/sex/group) for at least 70 days prior to mating, at dose levels of 0, 1.25, 2.5 or 5.0ml/kg/day (0, 1160, 2320 and 4630mg/kg/day). An additional group received a triacylglycerol (TAG) oil with a similar fatty acid composition to DAG oil. The rats were treated throughout the mating, gestation and lactation periods. Administration of DAG or TAG oil did not reveal any toxicologically significant effects on reproductive performance (mating, fertility and copulation/conception indices). DAG oil did not affect mean gestation lengths, the process of parturition, spermatogenic parameters, organ weights, histopathologic findings, mean numbers of pups born, implantation sites and unaccounted sites. F1 and F2 pup viability, live litter sizes, body weights, mean age of attainment of balanopreputial separation and vaginal patency were similar to those in the control group. Based on the results of this study, a dose level of 5.0ml/kg (4630mg/kg/day) was considered as the no-observed-adverse-effect level for reproductive and systemic toxicity, and neonatal toxicity.     

Safety assessment of EPA-rich triglyceride oil produced from yeast: Genotoxicity and 28-day oral toxicity in rats

The 28-day repeat-dose oral and genetic toxicity of eicosapentaenoic acid triglyceride oil (EPA oil) produced from genetically modified Yarrowia lipolytica yeast were assessed. Groups of rats received 0 (olive oil), 940, 1880, or 2820 mg EPA oil/kg/day, or fish oil (sardine/anchovy source) by oral gavage. Lower total serum cholesterol was seen in all EPA and fish oil groups. Liver weights were increased in the medium and high-dose EPA (male only), and fish oil groups but were considered non-adverse physiologically adaptive responses. Increased thyroid follicular cell hypertrophy was observed in male high-dose EPA and fish oil groups, and was considered to be an adaptive response to high levels of polyunsaturated fatty acids. No adverse test substance-related effects were observed on body weight, nutritional, or other clinical or anatomic pathology parameters. The oil was not mutagenic in the in vitro Ames or mouse lymphoma assay, and was not clastogenic in the in vivo mouse micronucleus test. In conclusion, exposure for 28 days to EPA oil derived from yeast did not produce adverse effects at doses up to 2820 mg/kg/day and was not genotoxic. The safety profile of the EPA oil in these tests was comparable to a commercial fish oil.     

One-generation reproductive toxicity study of DHA-rich oil in rats

Polyunsaturated fatty acids, including docosahexaenoic acid (DHA), are natural constituents of the human diet. DHA-algal oil is produced through the use of the marine protist, Ulkenia sp. The reproductive toxicity of DHA-algal oil was assessed in a one-generation study. Rats were provided diets containing DHA-algal oil at concentrations of 1.5, 3.0, or 7.5%, and the control group received a diet containing 7.5% corn oil. Males and females were treated for 10 weeks prior to mating and during mating. Females continued to receive test diets during gestation and lactation. In parental animals, clinical observations, mortality, fertility, and reproductive performance were unaffected by treatment. Differences in food consumption, body weight, and liver weight in the treated groups were not considered to be due to an adverse effect of DHA-algal oil. Spleen weight increases in treated animals were associated with extramedullary hematopoiesis. Yellow discoloration of abdominal adipose tissue was observed in rats from the high-dose group, and histological examination revealed steatitis in all treated parental groups. Exposure to DHA-algal oil did not influence the physical development of F(1) animals. These results demonstrate that DHA-algal oil at dietary concentrations of up to 7.5% in rats does not affect reproductive capacity or pup development.     

Safety assessment of EPA-rich oil produced from yeast: Results of a 90-day subchronic toxicity study

The safety of eicosapentaenoic acid (EPA) oil produced from genetically modified Yarrowia lipolytica yeast was evaluated following 90 days of exposure. Groups of rats received 0 (olive oil), 98, 488, or 976 mg EPA/kg/day, or GRAS fish oil or deionized water by oral gavage. Rats were evaluated for in-life, neurobehavioral, anatomic and clinical pathology parameters. Lower serum cholesterol (total and non-HDL) was observed in Medium and High EPA and fish oil groups. Lower HDL was observed in High EPA and fish oil males, only at early time points. Liver weights were increased in High EPA and Medium EPA (female only) groups with no associated clinical or microscopic pathology findings. Nasal lesions, attributed to oil in the nasal cavity, were observed in High and Medium EPA and fish oil groups. No other effects were attributed to test oil exposure. Exposure to EPA oil for 90 days produced no effects at 98 mg EPA/kg/day and no adverse effects at doses up to 976 mg EPA/kg/day. The safety profile of EPA oil was comparable to that of GRAS fish oil. These results support the use of EPA oil produced from yeast as a safe source for use in dietary supplements.     

Genotoxicity and subchronic toxicity studies of DHA-rich oil in rats

Polyunsaturated fatty acids, including docosahexaenoic acid (DHA), are natural constituents of the human diet. DHA-algal oil is produced through the use of the non-toxigenic and non-pathogenic marine protist, Ulkenia sp. The safety of DHA-algal oil was assessed in a subchronic toxicity study and in genotoxicity studies. In a 90-day study, rats were orally administered water or DHA-algal oil at concentrations of 0, 500, 1000, and 2000 mg/kg in combination with 2000, 1500, 1000 or 0 mg/kg DHA-containing fish oil, respectively. Additional animals were administered water, 2000 mg/kg DHA-algal oil, or 2000 mg/kg fish oil for 90 days, followed by a 4-week recovery phase. No treatment-related effects were observed in clinical observations, food and water consumption, mortality, gross pathology, and histopathology. Increased body weights and liver weights in oil-treated groups were attributed to the large lipid load and were not regarded as toxicologically significant. Furthermore, no treatment-related differences in the measured parameters between the DHA-algal oil and fish oil groups were detected. In genotoxicity experiments, DHA-algal oil exerted no mutagenic activity in various bacterial strains, nor did it induce chromosomal aberrations in Chinese hamster fibroblast cells. These results support the safety of DHA-algal oil as a dietary source of DHA.     

Toxicologic evaluation of Dichrostachys glomerata extract: Subchronic study in rats and genotoxicity tests

In western Cameroon, edible fruits and seeds from the plant Dichrostachys glomerata are commonly used as spices. Extract from the fruit pods has been reported as a good natural source of antioxidants and may provide health benefits. The objective of the present study was to investigate potential adverse effects, if any, of D. glomerata fruit pod extract (Dyglomera™) in a subchronic toxicity study and in genotoxicity studies. In the toxicity study, Sprague Dawley rats (20/sex/group) were gavaged with D. glomerata extract at dose levels of 0, 100, 1000 and 2500 mg/kg body weight (bw)/day for 90-days. Dyglomera™ administration did not result in mortality or show treatmentrelated changes in clinical signs of toxicity, body weights, body weight gain or feed consumption. Similarly, no toxicologically significant treatment-related changes in hematological, clinical chemistry, urine analysis parameters, and organ weights were noted. Macroscopic and microscopic examinations did not reveal treatment-related abnormalities. Mutagenic and clastogenic potentials as evaluated by Ames assay, in vitro and in vivo chromosomal aberration test and in vivo micronucleus test did not reveal any genotoxicity of the extract. The results of subchronic toxicity study supports the no-observed-adverse-effect level (NOAEL) for D. glomerata extract as 2500 mg/kg bw/day, the highest dose tested.     

Carbofuran in water: Subchronic toxicity to rats

Carbofuran toxicity on rats was studied during subchronic exposure. Female and male rats were administered carbofuran in drinking water in concentrations of 25, 100 and 400 ppm for a period of 90 days. Clinical symptoms, water consumption, body weight gain, organ weight, pathological and histopathological changes in the liver and kidneys were observed and biochemical and haematological examinations were carried out.

The results obtained show that carbofuran administered to rats caused a significant decrease in water consumption as well as in brain, serum and erythrocyte cholinesterase activities. Statistically significant increases in relation to the control were found in the serum enzyme activities.

The haematological data showed that carbofuran had no significant effect on Hb concentration and total RBC, but total WBC showed a significant statistical decrease. The histopathological changes in liver and kidneys were observed. However, cell regeneration in the liver and kidneys was found in all test groups.     

Safety assessment of Apoaequorin,a protein preparation: Subchronic toxicity study in rats

Apoaequorin, a calcium-binding protein originally isolated from jellyfish is available commercially as a dietary supplement. The objective of the present study was to investigate potential adverse effects, if any, of Apoaequorin, a recombinant protein preparation, in rats following subchronic administration. For this study, Sprague–Dawley (Hsd:SD®) rats (10/sex/group) were administered via oral gavage 0 (control), 92.6, 462.9, and 926.0 mg/kg body weight (bw)/day of Apoaequorin preparation, for 90 days. The corresponding amount of Apoaequorin protein was 0, 66.7, 333.3 and 666.7 mg/kg bw/day, respectively. Administration of the Apoaequorin preparation did not result in any mortality. There were no clinical or ophthalmological signs, body weight, body weight gain, food consumption, food efficiency, clinical pathology or histopathological changes attributable to administration of Apoaequorin. Any changes noted were incidental and in agreement with those historically observed in the age and strain of rats used in this study. Based on the results of this study, the No Observed-Adverse-Effect Level (NOAEL) for Apoaequorin was determined as 666.7 mg/kg bw/day, the highest dose tested.     

Subchronic toxicity study in rats fed gum karaya

Gum karaya was given to groups of 15 rats of each sex at levels of 0 (control). 0·2, 1 or 5% (w/w) in the diet for 13 wk. An increase in faecal bulk was seen in all treated groups throughout the study. There was a decrease in weight-gain at the highest dietary level (significant only in the females), which was associated with a marginal reduction in food-conversion efficiency. Males given 1 or 5% drank more than the controls and a transient increase in water intake was seen in females given the highest level. The no-untoward-effect level from this study was 5% (w/w) of the diet, providing a mean intake of about 4 g karaya gum/kg body weight/day.     

Subchronic toxicity study of peppermint oil in rats.

Peppermint oil was given p.o. to four groups of 28 rats at dosage levels of 0, 10, 40, and 100 mg/kg body wt. per day for 90 days. At the highest dose histopathological changes consisting of cyst-like spaces scattered in the white matter of cerebellum were seen. No other signs of encephalopathy were observed. Nephropathy was seen in the male rats in the highest dose group. A no-observed-adverse-effect level of 40 mg/kg body wt. per day was determined.     

FDA'S food ingredient approval process: Safety assurance based on scientific assessment

Fifty years ago, the Food and Drug Administration (FDA) began implementing new provisions of the Federal Food, Drug, and Cosmetic Act aimed at assuring the safety of new food additives before they enter the marketplace. Today, the agency's procedures for premarket evaluation of food additive safety have evolved into a scientifically rigorous, sound and dependable system whose objective and independent evaluations by FDA scientists assure that new food additives are safe for their intended uses before they arrive on the consumer's plate. Although controversy often surrounds food additives in the popular media and culture, and science-based challenges to FDA's decisions do arise, the agency's original safety judgments successfully withstand these challenges time and again. This article reviews the basic components of the FDA's decision-making process for evaluating the safety of new food additives, and identifies characteristics of this process that are central to assuring that FDA's decisions are marked by scientific rigor and high integrity, and can continue to be relied on by consumers.     

Non-clinical safety assessment of Hwangryunhaedok-tang: 13-week toxicity in Crl:CD Sprague Dawley rats

Hwangryunhaedok-tang (Huang-Lian-Jie-Du-Tang in Chinese, Oren-gedoku-to in Japanese) is a traditional herbal medicine with a long history of use for anti-inflammatory purposes. In this study, subchronic toxicity of daily oral administration of a Hwangryunhaedok-tang water extract (HHT) at 0, 250, 750, and 2000 mg/kg for 13 weeks was examined in rats. Mortality, clinical signs, and changes in body weight, food consumption, clinical signs, ophthalmological examination, urinalysis, hematology, serum biochemistry, gross observation, organ weight, and histopathology were monitored in accordance with Good Laboratory Practice and OECD guidelines. We found no mortality or abnormality in clinical signs, body weight, serum biochemistry, or organ weight in HHT-treated groups in either sex. However, there were significant changes in glucose, bilirubin, urobilinogen, protein (only male) in urine after 2000 mg/kg/day HHT treatment for both sexes. In hematological examinations, we found a significant decreased number of red blood cells (RBC), whereas, an increased the mean corpuscular volume, number of platelets, and rate of reticulocyte (RET) after 2000 mg/kg/day HHT treatment of male rats. In male and female rats, 750 and 2000 mg/kg/day HHT treatment decreased the number of RBC and increased RET. Histopathological examinations revealed stomach mucosal erosion in female rats (2000 mg/kg/day). No-observed-adverse-effect levels were established for 750 mg/kg HHT in rats under the conditions of this study. However, other toxicological studies are necessary to evaluate the safety of HHT fully.     

Safety assessment of mushroom β-glucan: Subchronic toxicity in rodents and mutagenicity studies

Mushroom β-glucan, a polymer of β-(1,3/1,6)-glucan, has been claimed for its health benefits. The objective of this study was to assess the safety in-use of mushroom β-glucan as dietary supplement and food ingredient. Hence, a subchronic toxicity and mutagenicity studies were conducted. In the subchronic toxicity study, Sprague Dawley rats (12/sex/group) were administered (gavage) mushroom β-glucan at dose levels of 0, 500, 1000 and 2000 mg/kg body weight (bw)/day for 90 days. As compared to control group, administration of β-glucan 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 adverse effects of the β-glucan on the hematology, serum chemistry parameters, urinalysis or terminal necropsy (gross or histopathology findings) were noted. The results of mutagenicity studies as evaluated by gene mutations in Salmonella typhimurium, in vitro chromosome aberrations and in vivo micronucleus test in mouse did not reveal any genotoxicity of β-glucan. Based on the subchronic study, the no observed-adverse-effect level (NOAEL) for mushroom β-glucan was determined as 2000 mg/kg bw/day, the highest dose tested.     

Evaluation of short-term and subchronic toxicity of magnolia bark extract in rats

Magnolia bark has been traditionally used in Chinese and Japanese medicines, and its extract is a constituent of currently marketed dietary supplements and cosmetic products. The safety of magnolia bark extract (MBE) was assessed in short-term and subchronic studies. In a 21-day pilot study, rats were administered MBE at levels of 0, 60, 120, 240 or 480 mg/kg body weight (bw)/day in the diet. There were no treatment-related effects in clinical observations, macroscopic or microscopic findings, hematological, clinical chemistry, urinalysis, or organ weight measurements, and there were no deaths or significant differences in body weight and weight gain. In the 90-day study, rats were administered 0, 60, 120 or 240 mg MBE/kg bw/day in the diet. No mortality, ophthalmic abnormalities or treatment-related findings in clinical observations, hematology, coagulation or organ weight measurements were observed. There were no treatment-related macroscopic or microscopic findings. Differences between treated and control groups in body weight, weight gain, food consumption and utilization, clinical chemistry and urinalysis parameters were not considered toxicologically significant as they were not dose-related and/or because values remained within historical control ranges. These results support the safety of MBE for oral consumption.     

Subchronic toxicity evaluation of γ-aminobutyric acid (GABA) in rats

γ-Aminobutyric acid (GABA) is an amino acid compound contained in vegetables such as tomatoes and also widely distributed in mammals. GABA acts as an inhibitory neurotransmitter and promotes parasympathetic activity to provide several beneficial effects, for instance, relaxation, anti-stress, and insomnia. GABA, produced via a fermentation process, has been available as a functional food ingredient. As part of a program to assess its safety, GABA was administered by oral gavage at doses of 500, 1250, and 2500 mg/kg body weight to groups of 10 male and 10 female Sprague–Dawley rats for 13 weeks. Treatment was not associated with the test substance-related mortality and appeared to be well tolerated. There were no toxicologically and statistically significant changes in urinalysis, hematology, clinical chemistry parameters, and in necropsy findings. A few statistically significant changes in food consumption and body weights were noted in the male groups while any significant changes were not noted in female groups. There was no effect of treatment on organ weights or on the results of the histopathological examinations. The results of toxicity evaluation support the safety use of GABA and the potential use as a functional food ingredient.     

Safety evaluation of a thermolysin enzyme produced from Geobacillus stearothermophilus

Thermolysin is a zinc metalloprotease that has potential uses in the food industry. The safety of thermolysin has not been demonstrated before, and therefore a series of standard toxicological tests to assess its potential toxicity was undertaken. The thermolysin used in this study was derived from the thermophilic bacterium Geobacillus stearothermophilus, which had undergone chemical mutagenesis to generate strains with increased thermolysin production. Acute toxicity studies in rats and mice showed that thermolysin powder is not acutely toxic with an oral LD₅₀ of more than 18,000 mg/kg (2520 mg/kg thermolysin protein) in rats and more than 24,000 mg/kg (3360 mg/kg protein) in mice. Subchronic feeding studies in rats for 91 days at doses up to 1000 mg/kg (390 mg/kg protein) revealed no significant differences between treated and non-treated groups and a No Observed Effect Level (NOEL) of 1000 mg/kg (390 mg/kg protein) per day was established. Results from genotoxicity tests such as in vitro chromosomal aberration assay and in vivo mouse micronucleus were negative. Allergenicity sequence analysis revealed no evidence suggesting that thermolysin is an allergen. The data presented in this study support the conclusion that thermolysin is safe for use in food production.