Safety assessment and gastrointestinal retention of orally administered cerium oxide nanoparticles in rats

Cerium oxide nanoparticles (CeO2 NPs, NM-212) are well-known for their catalytic properties and antioxidant potential, and have many applications in various industries, drug delivery, and cosmetic formulations. CeO2 NPs exhibit strong antimicrobial activity and can be used to efficiently remove pathogens from different environments. However, knowledge of the toxicological evaluation of CeO2 NPs is too limited to support their safe use. In this study, CeO2 NPs were orally administered to Sprague Dawley rats for 13 weeks at the doses of 0, 10, 100, and 1000 mg/kg bw/day, followed by a four week recovery period. The hematology values for the absolute and relative reticulocyte counts in male rats treated with 1000 mg/kg bw/day CeO2 NPs were lower than those in control rats. The clinical chemistry values for sodium and chloride in the treated male rat groups (100 and 1000 mg/kg/day) and total protein and calcium in the treated female rat groups (100 mg/kg/day) were higher than those in the control groups. However, these changes were not consistent in both sexes, and no abnormalities were found in the corresponding pathological findings. The results showed no adverse effects on any of the parameters assessed. CeO2 NPs accumulated in the jejunum, colon, and stomach wall of rats administered 1000 mg/kg CeO2 NPs for 90 days. However, these changes were not abnormal in the corresponding histopathological and immunohistochemical examinations. Therefore, 1000 mg/kg bw/day may be considered the "no observed adverse effect level" of CeO2 NPs (NM-212) in male and female SD rats under the present experimental conditions.

A toxicological assessment of spermidine trihydrochloride produced using an engineered strain of Saccharomyces cerevisiae

Spermidine is a polyamine consumed in the diet, endogenously biosynthesized in most cells, and produced by the intestinal microbiome. A variety of foods contribute to intake of spermidine along with other polyamines. Spermidine trihydrochloride (spermidine-3HCl) of high purity can be produced using an engineered strain of Saccharomyces cerevisiae. Spermidine has a demonstrated history of safe use in the diet; however, limited information is available in the public literature to assess the potential toxicity of spermidine-3HCl. To support a safety assessment for this spermidine-3HCl as a dietary source of spermidine, authoritative guideline and good laboratory practice (GLP) compliant in vitro genotoxicity assays (bacterial reverse mutation and mammalian micronucleus assays) and a 90-day oral (dietary) toxicity study in rats were conducted with spermidine-3HCl. Spermidine-3HCl was non-genotoxic in the in vitro assays, and no adverse effects were reported in the 90-day oral toxicity study up to the highest dose tested, 12500 ppm, equivalent to 728 mg/kg bw/day for males and 829 mg/kg bw/day for females. The subchronic no observed adverse effect level (NOAEL) is 728 mg/kg bw/day.

Acute and subchronic oral toxicity study of Camelina sativa oil in Wistar rats

Objective

The aim of these studies was to ascertain if Camelina sativa oil is harmful in both the acute and subchronic states.

Methods

Wistar rats of both sexes were used in an acute toxicity test, and the fatal dosage (LD50) of oral Camelina sativa oil was greater than 27.6 g/kg bw. Rats were gavaged with Camelina sativa oil at dosages of 0.00, 0.92, 1.84, and 3.68 g/kg bw per day for 90 days. In addition, satellite groups were established in the control and high-dose groups for a 28-day recovery period. The following factors were assessed: mortality, clinical anomalies, body weight, food intake, hematological, serum biochemistry, urine, gross necropsy, and histology.

Results

There were no observable toxicity-related changes in any of the three dosage groups. There is no toxicological relevance to the change in the high-dose hematological indicator PLT at the conclusion of the recovery period because it was within the usual range for this strain in our laboratory. The test material did not result in any pathological alterations, according to a pathological examination.

Conclusion

Since the results of the current study, the no-observed-adverse-effect-level (NOAEL) for Camelina sativa oil in rats has been determined to be greater than 3.68 g/kg bw.

Evaluation of subchronic toxicity of the compound of diphenhydramine hydrochloride and caffeine after 28 days of repeated oral administration in Sprague-Dawley rats and beagle dogs

This study was designed to evaluate the subchronic toxicity of the compound of diphenhydramine hydrochloride (DH) and caffeine in Sprague-Dawley (SD) rats and beagle dogs. A total of 180 SD rats (15/sex/group) were randomly divided into the compound low-, medium- and high-dose groups (51, 102, 204 mg/kg), DH group (60 mg/kg), caffeine group (144 mg/kg) and the vehicle control group. Sixty beagle dogs (5/sex/group) were randomly divided into the compound low-, medium- and high-dose groups (male: 14.20, 28.30, 56.60 mg/kg, female: 5.66, 14.20, 28.30 mg/kg), DH group (male: 16.60 mg/kg, female: 8.30 mg/kg), caffeine group (male: 40.00 mg/kg, female: 20.00 mg/kg) and the vehicle control group. Rats and dogs were given continuous oral administration for 28 days following a 28-day recovery period. The adverse effects of the compound on rats and beagle dogs mainly included anorexia and liver function impairment. Most adverse effects induced by administration were reversible. Under the experimental conditions, the no-observed-adverse-effect level (NOAEL) of the compound of DH and caffeine was 51 mg/kg/day for SD rats and 28.30 mg/kg/day (male) and 5.66 mg/kg/day (female) for beagle dogs.

Systemic subchronic toxicity and comparison of four selenium nutritional supplements by 90-day oral exposure in Sprague-Dawley rats

To evaluate and compare the safety of four selenium supplements, namely Se-enriched peptides (SeP), yeast selenium (SeY), L-Se-methylselenocysteine (L-SeMc) and sodium selenite (Na2SeO3), the subchronic toxicity study was designed by 90-day gavage administration in Sprague-Dawley rats. The doses of SeP, SeY, L-SeMc and Na2SeO3 were 0.15, 0.30 and 0.60 mg/kg bw/day, with additional dose of 0.45 mg/kg L-SeMc (All dose calculated as Se). Symptoms like growling, hair loss and significant weight loss were found at 0.60 mg/kg of L-SeMc, but not in other groups. At the dose of 0.60 mg/kg, females in Na2SeO3, SeY and L-SeMc groups showed significant elevations in ALT and/or ALP. Pathologic manifestations such as bile duct hyperplasia and cholestasis were predominantly found in females at 0.6 mg/kg of L-SeMc and SeY groups, and in males at same dose of L-SeMc group showed marked testicular atrophy. 0.60 mg/kg of SeY and Na2SeO3, and 0.30, 0.45, 0.60 mg/kg of L-SeMc induced significant reductions in sperm motility rates, rapid movement and amount. In conclusion, the NOAEL of SeP, SeY, L-SeMc, Na2SeO3 was all 0.30 mg/kg for female, and 0.60, 0.30, 0.15 and 0.30 mg/kg for male respectively. Liver and reproductive organs are possible toxic target organs of hyper selenium.

The food safety assessment of all-female common carp (Cyprinus carpio) (cyp17a1+/-;XX genotype) generated using genome editing technology

There are several technical challenges and public issues concerning genome editing applications before they become viable in commercial aquaculture. Recently, we developed a novel strategy to generate all-female (AF) common carp, which exhibited a growth advantage over the control carp, using genetic editing through single gene-targeting manipulation. Here, we found that the body weight of the AF common carp was higher by 22.58% than that of the control common carp. Because the genotype of the AF common carp was cyp17a1+/-;XX, the contents of sex steroids were normally synthesized, as they were comparable to that of the control female carp. To evaluate the food safety of the AF carp, Wistar rats were fed a diet containing control female carp (control, C) or all-female (AF) carp at an incorporation rate of 5, 10 and 20% (w/w) for 90 days. Compared with those fed control carp, the rats fed AF common carp exhibited no significant difference in body weight, food intake, feed conversion ratio, hematology, serum biochemistry, urine test, relative organ weight, gross necropsy, and histopathological examination. This is the first food safety assessment of the farmed fish strain cultured using CRISPR/Cas9, which will further advance the fishery development of genome-edited animals.

Toxicity of a 90-day repeated oral dose of a collagen peptide derived from skate (Raja kenojei) skin: a rat model study

Collagen peptides are widely employed as therapeutic materials due to their numerous beneficial properties, including for the following uses: antiaging, antioxidant applications, antibacterial applications, wound healing, tissue engineering, medication delivery, and cosmetics. Although collagen peptides are useful in these applications, to our knowledge, few published studies have been undertaken on their repeated-dose toxicity. We evaluated the possible subchronic toxicity of a collagen peptide derived from skate (Raja kenojei) skin (CPSS) in Sprague-Dawley rats by administering repeated oral doses over 90 days. Rats of both sexes were assigned randomly to one of four experimental groups, respectively receiving 0, 500, 1000, or 2000 mg/kg/day of CPSS. At all doses tested, repeated oral CPSS administration had no treatment-related adverse effects in terms of clinical signs, body weight, food consumption, detailed clinical observation, sensory reactivity, functional assessment, urinalysis, ophthalmic examination, gross pathology, hematology, serum biochemistry, hormone analysis, organ weight, and histopathology. Even though there were some alterations in hematologic parameters, serum biochemistry parameters, organ weight, and histopathological findings, these did not follow a dose-response pattern and were within historical limits for control rats. The oral no-observed-adverse-effect level (NOAEL) of the CPSS was 2000 mg/kg/day for both male and female rats in the applied experimental circumstances, and no target organs were identified.

Chlorine substitution-dependent toxicities of polychlorinated biphenyls to the earthworm Eisenia fetida in soil

Polychlorinated biphenyls (PCBs) with different chlorine substitution patterns often coexist in e-waste-processing sites. However, the single and combined toxicity of PCBs to soil organisms and the influence of chlorine substitution patterns remain largely unknown. Herein, we evaluated the distinct in vivo toxicity of PCB28 (a trichlorinated PCB), PCB52 (a tetrachlorinated PCB), PCB101 (a pentachlorinated PCB), and their mixture to earthworm Eisenia fetida in soil, and looked into the underlining mechanisms in an in vitro test using coelomocytes. After a 28-days exposure, all PCBs (up to 10 mg/kg) were not fatal to earthworms, but could induce intestinal histopathological changes and microbial community alterations in the drilosphere system, along with a significant weight loss. Notably, pentachlorinated PCBs with a low bioaccumulation ability showed greater inhibitory effects on the growth of earthworm than lowly chlorinated PCBs, suggesting that bioaccumulation was not the main determinant of chlorine substitution-dependent toxicity. Furthermore, in vitro assays showed that the highly chlorinated PCBs induced a high-percentage apoptosis of eleocytes in the coelomocytes and significantly activated antioxidant enzymes, indicating that the distinct cellular vulnerability to lowly/highly chlorinated PCBs was the main contributor to the PCBs toxicity. These findings emphasize the specific advantage of using earthworms in the control of lowly chlorinated PCBs in soil due to their high tolerance and accumulation ability.

Marine toxin C17-SAMT causes major structural damage to vital organs in mice following subchronic toxicity trials

C17-sphinganine analog mycotoxin (C17-SAMT) has been characterized as the contaminant responsible for the atypical toxicity reported in mussels from the Bizerte lagoon (northern Tunisia) over the past decade. C17-SAMT exhibited common symptoms of toxicity in mice, including flaccid paralysis and severe respiratory distress, followed by rapid death. To determine the potential health risks of this neurotoxin, we assessed its subchronic toxicity according to the recommendations of OCDE n° 407. The body weight and the structural changes of vital organs were recorded. Biochemical and hematological parameters were also quantified. Macroscopic observations showed that mice treated with 0.9, 9, and 90 µg/kg C17-SAMT had significantly reduced stomach weights, swollen and fragile intestines, and signs of nephritis with renal abscesses. Transaminase assays pointed out that exposure to C17-SAMT can lead to transaminitis. Above-average lactate dehydrogenase values were recorded in both the treated and satellite groups. Hematology data showed a significant reduction in red blood cell counts in high-dose-treated group. Reductions in hemoglobin and hematocrit were also recorded. Mean leukocyte counts were significantly elevated in the high-, mid-dose treated and satellite groups. At the microscopic level, we noted myocardial atrophy and hyperemia. In the lungs, we noted necrosis associated with macrophages perivascular infiltration and congestion. The kidneys showed mild inflammation and glomerular atrophy. The stomach exhibited mucosal atrophy, while a thin colon and distended small intestine were observed in high-dose-treated group. The liver was affected by vascular congestion, inflammatory infiltration, and lobular necrosis that evolved into acute hepatitis. Lesions, such as inflammatory infiltration and mild necrosis of the liver, cortical abscess with central necrosis in the kidney, and mild congestion of cardiac tissue were recorded in the satellite group.

Oral toxicity evaluation of cannabidiol

Use of cannabidiol (CBD) in humans has increased considerably in recent years. While currently available studies suggest that CBD is relatively safe for human consumption, data from publicly available studies on CBD conducted according to modern testing guidelines are lacking. In the current study, the potential for toxicity following repeated oral exposure to hemp-derived CBD isolate was evaluated in male and female Sprague Dawley rats. No adverse treatment-related effects were observed following administration of CBD via oral gavage for 14 and 90 days at concentrations up to 150 and 140 mg/kg-bw/d, respectively. Microscopic liver and adrenal gland changes observed in the 90-day study were determined to be resolved after a 28-day recovery period. CBD was well tolerated at these dose levels, and the results of this study are comparable to findings reported in unpublished studies conducted with other CBD isolates. The current studies were conducted as part of a broader research program to examine the safety of CBD.

Effect of different exposure times and doses of cyantraniliprole on oxidative stress and genotoxicity in earthworms (Eisenia fetida)

Cyantraniliprole, the second generation of diamide insecticides, is widely used to control various pests, which will certainly result in adverse effects on earthworms in soil. In this study, after exposure with six doses of cyantraniliprole (0, 0.5, 1, 2.5, 5, and 10 mg kg^-1) by artificial soil method, six biomarkers, four functional genes, and histopathological changes of Eisenia fetida were measured on the 7th, 14th, 21st, and 28th days. The comprehensive toxicity was assessed by the IBR version 2 (IBRv2) method. The results showed that the reactive oxygen species (ROS) level was induced significantly. The superoxide dismutase (SOD) activity was activated in 7-28 days. The catalase (CAT) and glutathione S-transferases (GST) activities were also activated in the initial 14 days. The 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) contents in the high treatment increased until the late stage of exposure. On the 28th day, the metallothionein (MT) and calreticulin (CRT) genes were up-regulated, the transcriptionally controlled tumor protein (TCTP) gene was down-regulated. The SOD gene showed a good correlation with SOD activity. Extensive histopathological damage was found in the endoderm and ectoderm of E. fetida. The 5 and 10 mg kg^-1 treatments showed higher comprehensive toxicity than the 0.5, 1, and 2.5 mg kg^-1 treatments on the 28th day. These results suggest that cyantraniliprole exerted certain subchronic toxic effects of oxidative stress, DNA damage, and histopathological changes to E. fetida, which provided theoretical basis for rational use of cyantraniliprole and evaluation of its safety to soil environment.

A 90-day rodent feeding study with grain for genetically modified maize L4 conferring insect resistance and glyphosate tolerance

A 90-day rat feeding study was performed to conduct a safety assessment on L4, a multi-gene genetically modified maize, conferring "Bt" insect resistance and glyphosate tolerance. A total of 140 Wistar rats were assigned to seven groups, 10 animals/group/sex, which comprised three genetically modified groups fed diets containing different concentrations of L4, three corresponding non-genetically modified groups fed diets containing different concentrations of zheng58 (parent plants), and a basal diet group fed the standard basal diet for 13 weeks. The fed diets contained L4 and Zheng58 at w/w% percentages of 12.5%, 25.0%, and 50% of the total. Animals were evaluated on some research parameters, including general behaviour, body weight/gain, feed consumption/efficiency, ophthalmology, clinical pathology, organ weights, and histopathology. Throughout the feeding trial, all animals were in good condition. No mortality and no biologically relevant effects or toxicologically significant alterations were observed in the total research parameters of the rats in the genetically modified groups compared with those in the basal diet group or their corresponding non-genetically modified groups. No adverse effects were observed in any of the animals. The results indicated that L4 is as safe and wholesome as conventional, non-genetically modified control maize.

Subchronic toxicity study of ferric oxide nanoparticles through intragastric administration: A 94-d, repeated dose study in Sprague Dawley rats

In this study, the toxicity of ferric oxide nanoparticles (Fe₂O₃ NPs) administered through gavage to Sprague Dawley (SD) rats for 94 d, consecutively and the recovery after Fe₂O₃ NPs withdrawal for 30 d were evaluated. The vehicle control group, low-, medium-, and high-dose groups were administered with the vehicle (0.5% sodium carboxymethyl cellulose [CMC-Na]), 125, 250, and 500 mg/kg of Fe₂O₃ NPs, respectively, administered every morning for 94 d. There was no significant difference in the body weight, food intake, hematological, blood biochemical, and urine indices of SD rats in each administration group and the control group (P > 0.05). There was no significant difference in organ weight, organ indices, and the coefficient of the visceral brain between the SD rats in the different dosage groups and the SD rats in the vehicle control group (P > 0.05). Histopathological observations showed that there was no correlation between the pathological lesions of the organs observed in this study and the dose of Fe₂O₃ NPs (P > 0.05). The no-observed-adverse-effect level (NOAEL) dose of Fe₂O₃ NPs was initially determined to be 500 mg/kg administered to SD rats through oral gavage for 94 d, consecutively, followed by recovery after Fe₂O₃ NPs withdrawal for 30 d.

Cyhalofop-butyl and pyribenzoxim-induced oxidative stress and transcriptome changes in the muscle of crayfish (Procambarus clarkii)

Cyhalofop-butyl and pyribenzoxim are commonly used herbicides in rice-crayfish co-culture fields. In actual production, weed control in paddy fields is inseparable from cyhalofop-butyl and pyribenzoxim, while its risk to P. clarkii is still unclear. The present study investigated the risk of acute and subchronic toxicity of cyhalofop-butyl and pyribenzoxim to P. clarkii. The results showed that cyhalofop-butyl and pyribenzoxim exposure for 28 days could accumulate in P. clarkii muscle and inhibit P. clarkii growth. Further research found that the malondialdehyde (MDA) level and glutathione-S-transferase (GST) activity in muscle of P. clarkii were significantly increased after exposure to cyhalofop-butyl and pyribenzoxim (4 days and 28 days), and the superoxide dismutase (SOD) and catalase (CAT) activities were significantly altered. Histological results also confirmed cyhalofop-butyl and pyribenzoxim-induced muscle damage in P. clarkii. Additionally, after 28 days exposure to 1.02 mg/L cyhalofop-butyl and 10.4 mg/L pyribenzoxim, transcriptome analysis identified 2029 and 4246 differentially expressed genes (DEGs), respectively. Exposure to 1.02 mg/L cyhalofop-butyl significantly altered metabolism-related pathways, such as drug metabolism-other enzymes, glutathione metabolism, drug metabolism-cytochrome P450, fatty acid biosynthesis and fatty acid degradation. While the pathways related to antioxidant system and nutrient substances synthesis and metabolic were significantly enriched after exposure to 10.4 mg/L pyribenzoxim. This research has significant implications for scientific and rational use of herbicides under rice-crayfish co-culture and will contribute to the development of the highly productive agricultural model.

A 13-week subchronic toxicity study of heme iron in SD rats

Heme iron (HI) has been widely used as a food additive and supplement to support iron fortification. However, no sufficient toxicological data to evaluate the safety of HI have been reported. In the current study, we performed a 13-week subchronic toxicity study of HI in male and female Crl:CD(SD) rats. Rats were orally administered HI in the diet at concentrations of 0%, 0.8%, 2%, and 5%. Observations of general condition, body weight (bw) and food consumption, urinalysis, hematology, serum biochemistry, and macroscopic and histopathological examination were performed. The results showed that HI had no adverse effects on any of the examined parameters. Therefore, we concluded that the no-observed-adverse-effect level (NOAEL) for HI was estimated to be 5% for both sexes (2,890 mg/kg bw/day for males and 3,840 mg/kg bw/day for females). Since the iron content of HI used in this study was in a range of 2.0-2.6%, iron content at NOAEL for HI was calculated to be 57.8-75.1 mg/kg bw/day for males and 76.8-99.8 mg/kg bw/day for females.

Research on 90-day subchronic toxicities of the ethanol extract from the cultivated Fritillaria Cirrhosa bulbs by oral administration in Sprague-Dawley rats

Fritillaria Cirrhosa bulbus (BFC) is a Chinese herbal medicine. In the present study, subchronic toxicities of the ethanol extract from cultivated Fritillaria Cirrhosa bulbus (ECBFC) were performed by oral daily administration in Sprague-Dawley rats. The subchronic toxicity test of ECBFC was conducted at doses of 0.34, 0.68, and 2.04 g/kg/day for 90 days (equivalent to the highest human clinical recommend dosage of 25, 50, and 150-fold) with a 4-week satellite group. No mortality or significant changes in behaviors, body weight and food consumption were observed during the experimental and recovery periods. According to the data from ematological analysis, biochemistry, organ coefficient and the results of histopathology, the ECBFC have toxicity to the spleen and liver at the highest (2.04 g/kg), medium (0.68 g/kg) dose and nephrotoxicity at the highest dose. Subchronic oral toxicity of ECBFC in SD rats (90 days) with NOAEL was 0.34 g/kg and LOAEL was 0.68 g/kg. In addition, the toxicity is gender neutral and reversible. The NOAEL value (0.34 g/kg) is 25-fold of the highest human clinical recommend dosage thus the ECBFC could be long-term used as Chinese patent medicine or functional food.

Acute and subchronic toxicity profile of methanol extract of leaves of Fimbristylis miliacea (L.) Vahl

Ethnopharmacological relevance

Fimbristylis miliacea (L.) Vahl (Cyperaceae) is a grass like herb habitually breeds as weed in paddy fields and mostly disseminated in tropical or sub-tropical countries of south and south-east Asia, northern Australia, and west Africa. The plant has been traditionally used to treat fever as a form of poultice. However, no scientific study regarding its toxicity profile has been testified.

Aim of the study

The study has been carried out to determine the potential toxicity of the methanol extract from leaves of the Fimbristylis miliacea, employing the technique of acute and subchronic oral administration in mice.

Materials and methods

In the acute toxicity study according to OECD guideline 425, oral administration of FM methanol extract at single doses of 2000 and 5000 mg/kg in both sexes of Swiss albino mice was performed. Toxic symptoms, abnormal behavior, changes in body weight, and mortality were observed for 14 consecutive days. In subchronic toxicity study according to OECD guideline 407, plant extract was administered orally at doses of 100, 500, 1000, and 2000 mg/kg daily for 28 days. The general toxic symptoms, abnormal behavior, changes in body weight were observed daily. Biochemical analysis of serum, and histopathological examination of liver were performed at the end of the study.

Results

No mortality, abnormal behavior and urination, changes in sleep, food intake, adverse effect, and non-linearity in body weight have been recorded during acute toxicity study at the doses of 2000 and 5000 mg/kg. Also, in subchronic toxicity study, FM extract produced no mortality or any kind of adverse effects in regards of general behavior, body weight, urination, sleeping routine, and food intake. In case of analysis of thirteen different biochemical parameters, concentrations of aspartate transaminase (AST) and glucose were altered significantly in male and female mice in both acute and subchronic study. Total cholesterol and triglycerides at 5000 mg/kg.bw were changed in male mice in acute toxicity study. On the other hand, female mice had altered triglycerides in subchronic test. All other critical parameters were found unaffected. In subchronic test, histopathological examination of liver demonstrated cellular necrosis at 2000 mg/kg.bw in both male and female mice while minor necrosis was observed at 1000 mg/kg.bw. Thus, the no observed adverse effect level (NOAEL) can be assumed around 1000 mg/kg.bw.

Conclusion

The present study suggests that treatment with FM extract does not reveal significant toxicity.

Non-clinical safety evaluation of salvianolic acid A: acute, 4-week intravenous toxicities and genotoxicity evaluations

BACKGROUND

Toxicological problem associated with herbal medicine is a significant public health problem. Hence, it is necessary to elaborate on the safety of herbal medicine. Salvianolic acid A (SAA) is a major active compound isolated from Danshen, a popular herbal drug and medicinal food plant in China. The aim of the present study was to explore the toxicological profile of SAA.

METHODS

The acute toxicity studies were performed in mice and Beagle dogs with single administration with SAA. A 4-week subchronic toxicity was test in dogs. SAA was intravenously administered at doses of 20, 80 and 300 mg/kg. Clinical observation, laboratory testing and necropsy and histopathological examination were performed. The genotoxic potential of SAA was evaluated by 2 types of genotoxicity tests: a reverse mutation test in bacteria and bone marrow micronucleus test in mice.

RESULTS

In acute toxicities, the LD50 of SAA is 1161.2 mg/kg in mice. The minimum lethal dose (MLD) and maximal non-lethal dose (MNLD) of SAA were 682 mg/kg and 455 mg/kg in dogs, respectively. The approximate lethal dose range was 455-682 mg/kg. In the study of 4-week repeated-dose toxicity in dogs, focal necrosis in liver and renal tubular epithelial cell, the decrease in relative thymus weight, as well as abnormal changes in biochemical parameters, were observed in SAA 80 or 300 mg/kg group. The no observed adverse effect level (NOAEL) of SAA was 20 mg/kg. Thymus, liver and kidneys were the toxic targets. These toxic effects were transient and reversible. These results indicated that it should note examination of liver and kidney function during the administration of SAA in clinic. Furthermore, SAA had no mutagenic effect at any tested doses.

CONCLUSION

These results provide new toxicological information of SAA for its clinical application and functional food consumption.

Toxicity of Nanocomplexes Containing Gadolinium Orthovanadate Nanoparticles and Cholesterol

Previous studies have shown the ability of nanocomplexes (NCs), which consist of nanoparticles (NPs) of orthovanadates of rare earth metals (GdYVO₄:Eu³⁺) and cholesterol, to inhibit the growth of Ehrlich's ascites carcinoma (EAC). However, the biosafety of these NCs remains unclear. Our objective was to investigate the acute and subchronic toxicity of NCs. NCs were administered to BALB/c mice in NPs concentration of 5.9; 29.5; 59.1; and 118.2 mg/kg. Acute toxicity was induced by a single administration of NCs, subchronic-by repeated daily administration of NCs for 14 days. On day 15 and on day 31 for acute and subchronic toxicity, respectively, the percentage of animal survival, body weight, condition of visceral organs, and activities of γ-glutamyl transferase (GGT) and glucose-6-phosphate dehydrogenase (G-6-PDH) were determined. It was found that administration of NCs in the concentration of 5.9 mg/kg and 29.5 mg/kg of NPs did not influence on survival of animals or have a negative impact on their performance status, morphological and quantitative characteristics of visceral organs, and activities of the GGT and G-6-PDH in the liver. For acute toxicity, the semi-lethal dose (LD₅₀) of nanocomplexes was determined (118.2 mg/kg of NPs). As to subchronic toxicity, it was found that repeated (for 14 days) administration of NCs containing 59.1 mg/kg of NPs decrease survival of animals to 50%. The coefficient of accumulation (C_acum = 7) indicates the low accumulative ability of NCs upon long-term use. Thus, from the LD₅₀ and accumulation coefficient, NCs can be referred to as low-toxic substances and used in conditionally therapeutic doses in oncological practice to develop nanostructured formulations of drugs.

Genotoxicity, acute and subchronic toxicity evaluation of fermented Morinda officinalis

Morinda officinalis has diverse pharmacological effects and has the potential to be used as functional food and medicine. Fermentation is traditionally used to process Morinda officinalis. However, the toxicological profile of fermented Morinda officinalis (FMO) is not reported. In the present study, the toxicological characteristics of FMO were assessed for the first time. FMO did not show any genotoxicity based on the Ames test, mammalian erythrocyte micronucleus test, and mouse primary spermatocyte chromosome aberration test. FMO administered by gavage in mice and rats at a dose of 20 g/kg BW did not induce death or toxicity based on acute study, indicating that FMO could be regarded as non-toxic at the tested dose. In the 90-day subchronic toxicity study, rats fed with FMO at the maximum dose of 8 g/kg BW did not affect mortalities, BW, food consumption, organ weights, hematology, serum biochemistry, or urinalysis. The no observed adverse effect level of FMO in both sexes was not less than 8 g/kg BW/day based on subchronic toxicity. The obtained results support the safe use of FMO as functional food and medicine.

Neurotoxic, biotransformation, oxidative stress and genotoxic effects in Astyanax altiparanae (Teleostei, Characiformes) males exposed to environmentally relevant concentrations of diclofenac and/or caffeine

The present study evaluated neurotoxic, biotransformation, genotoxic and antioxidant responses to relevant environmental concentrations of diclofenac (0.4 μg L^-1) and caffeine (27.5 μg L^-1), separate and combined, in adult males of the freshwater fish Astyanax altiparanae after a subchronic exposure (14 days). Fish exposed to diclofenac and caffeine, both separate and combined, revealed a neurotoxic effect through the inhibition of acetylcholinesterase activity in the muscle, while diclofenac alone and in combination caused cyclooxygenase inhibition. Caffeine alone produces genotoxicity on this species but, when combined with diclofenac, it potentiates hepatic lipoperoxidation and the inhibition of oxidative stress enzymes, while diclofenac alone or in combination produces a general inhibition of important enzymes. This study suggests that aquatic contamination produced by these pharmaceuticals has the potential to affect homeostasis and locomotion in A. altiparanae and compromise their immune system and general health.

Acute and subchronic 90-days toxicity assessment of propyl-propane-thiosulfinate (PTS) in rats

The organosulfur compounds (OSC) extracted from Allium spp. exhibit antibacterial, antifungal, and antioxidant properties. The agri-food industry is taking advantage of these properties by using them as natural feed and food additives. In the present work, an acute and a subchronic 90-days toxicity studies have been conducted for the first time to assess the safety of the OSC propyl-propane-thiosulfinate (PTS). Both studies were carried out following the Organization for Economic Co-operation and Development test guidelines (425 and 408, respectively). The acute study provided a maximum tolerated dose (MTD) of 175 mg/kg and the subchronic study established the Non Observed Adverse Effect Level (NOAEL) ≥ 55 mg/kg body weight (b.w.)/day in both sexes. In addition, the subchronic study performed on rats exposed to 14, 28 and 55 mg/kg b.w./day PTS, revealed no changes in any of the hematological parameters measured as well as no differences in body weight and water/food consumption. However, biochemical parameters were altered in some groups, although they were not biologically significant (Ca2+ in female rats, and the thyroids hormones T3 and T4 in rat males). Furthermore, the histopathological assessment evidenced no abnormality on the gastrointestinal, respiratory, lymphoid, urinary, circulatory, nervous, musculoskeletal, and reproductive systems.

Phytochemical identification, acute and subchronic oral toxicity assessments of hydroalcoholic extract of Acroptilon repens in BALB/c mice: A toxicological and mechanistic study

Acroptilon repens (L.) DC, commonly known as Rhaponticum repens, is a popular traditional phytomedicine. The current study was conducted to evaluate the acute and subchronic toxicity of the hydroalcoholic extract of this herb with regard to its terpenoid contents in a BALB/c mice model and to investigate the toxicity of this medicinal herb. Identification of extract components of the plant was done using gas chromatography (GC)-mass spectrometry. In order to establish the acute toxicity model, a single dose of 2000 mg/kg of the extract was given orally to male mice and in the subchronic toxicity study, the extract was consecutively administered at doses 250, 500, and 1000 mg/kg for 28 days. After 28 and 42 days, signs of toxicity and mortality were observed. Organ weight changes and the toxicity-associated parameters such as biochemical indicators, oxidative stress indices, mitochondrial parameters, apoptosis-associated gene expression levels, and pro-inflammatory cytokines were evaluated along with the histopathological examination. GC analysis showed that the terpenoids are the major components of the extract. The LD50 value (2 g/kg) was obtained in the acute toxicity assay; the subchronic administration caused a significant elevation in the serum biomarkers as well as in the levels of lipid peroxidation, protein carbonyl, and ROS. Besides, significant reductions in the superoxide dismutase and catalase activities were observed. This toxic effect was further confirmed by histological studies, cytokine assay, and gene expression assays. Following the treatment discontinuation, the abnormalities in the values of biochemical parameters and histopathological changes returned to normal. These findings demonstrate that the subchronic administration of the hydroalcoholic extract of A. repens can reversibly cause toxicity by inducing oxidative stress and mitochondrial dysfunction.

90-day nose-only inhalation toxicity study of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in Sprague-Dawley rats

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the key tobacco-specific nitrosamines that plays an important role in human lung carcinogenesis. Repeated dose inhalation toxicity data on NNK, particularly relevant to cigarette smoking, however, is surprisingly limited. Hence, there is a lack of direct information available on the carcinogenic and potential non-carcinogenic effects of NNK via inhalational route exposure. In the present study, the subchronic inhalation toxicity of NNK was evaluated in Sprague Dawley rats. Both sexes (9-10 weeks age; 23 rats/sex/group) were exposed by nose-only inhalation to air, vehicle control (75% propylene glycol), or 0.2, 0.8, 3.2, or 7.8 mg/kg body weight (BW)/day of NNK (NNK aerosol concentrations: 0, 0, 0.0066, 0.026, 0.11, or 0.26 mg/L air) for 1 h/day for 90 consecutive days. Toxicity was evaluated by assessing body weights; food consumption; clinical pathology; histopathology; organ weights; blood, urine, and tissue levels of NNK, its major metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and their glucuronides (reported as total NNK, tNNK, and total NNAL, tNNAL, respectively); tissue levels of the DNA adduct O6-methylguanine; blood and bone marrow micronucleus (MN) frequency; and bone marrow DNA strand breaks (comet assay). The results showed that NNK exposure caused multiple significant adverse effects, with the most sensitive endpoint being non-neoplastic lesions in the nose. Although the genotoxic biomarker O6-methylguanine was detected, genotoxicity from NNK exposure was negative in the MN and comet assays. The Lowest-Observed-Adverse-Effect-Level (LOAEL) was 0.8 mg/kg BW/day or 0.026 mg/L air of NNK for 1 h/day for both sexes. The No-Observed-Adverse-Effect-Level (NOAEL) was 0.2 mg/kg BW/day or 0.0066 mg/L air of NNK for 1 h/day for both sexes. The results of this study provide new information relevant to assessing the human exposure hazard of NNK.

Toxicological and pharmacological effects of pentacyclic triterpenes rich fraction obtained from the leaves of Mansoa hirsuta

Mansoa hirsuta is a medicinal plant native to the Brazilian semi-arid region. This approach aimed to investigate the in vitro and in vivo toxicity and anti-inflammatory and analgesic actions of the M. hirsuta fraction (MHF). In vitro cell viability was assessed in 3T3 cells. In vivo, the acute toxicity test, a single dose of the MHF was administered. For the subchronic toxicity test, three doses of were administered for 30 days. Locomotion and motor coordination were assessed using open field and rota-rod. The anti-inflammatory activity was evaluated in carrageenan-induced paw edema and zymosan-induced air-pouch models. Myeloperoxidase (MPO) and total proteins were also measured. The antinociceptive activity MHF was determined using acid acetic-induced abdominal writhing and formalin models. In the cytotoxicity assay, MHF showed no significative impairment of cell viability and in the acute toxicity study, did not cause mortality or signs of toxicity. Repeated exposure to MHF did not cause relevant toxicological changes. The evaluation in the open field test showed that the MHF did not alter the locomotor activity and there was no change in motor coordination and balance of animals. MHF significantly reduced edema, MPO production, the migration of leukocytes and protein leakage. In addition, MHF reduced abdominal writhing and significantly inhibited the first and second stage of the formalin test. The results of this study indicated that MHF has an anti-inflammatory and analgesic potential without causing acute or subchronic toxic effects and it can be a promising natural source to be explored.

A 90-day subchronic toxicity study of Myrrh in F344 rats

Myrrh is a flavoring agent and food additive. Here, we performed a subchronic toxicity study of Myrrh in male and female F344 rats by feeding at 5,000, 15,000 and 50,000 ppm for 90 days. No deaths or clinical signs were observed. Suppression of body weight gain was observed from the early phase of administration in both males and females in the 50,000 ppm group. Because there were no obvious changes in food intake in any of the Myrrh groups compared with the control group, suppression of body weight gain was considered an adverse effect of Myrrh. Hematology and serum biochemistry parameters with significant changes observed in the Myrrh groups were considered to have no toxicological significance. We observed a significant increase in relative kidney weight in male rats treated with 50,000 ppm Myrrh; this effect was considered to be related to the appearance of hyaline droplets in the epithelium of the proximal tubules histopathologically observed in this group. Immunohistochemical staining with anti-α_2u-globulin antibodies suggested that these hyaline droplets were caused by factors other than α_2u-globulin deposition. Thus, the no-observed-adverse-effect level of Myrrh was determined to be 15,000 ppm (males: 0.85 g/kg/day, females: 0.95 g/kg/day).

extract: Genotoxicity, acute toxicity, and 13-week subchronic toxicity study in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Platycodon grandiflorus (Jacq.) A.DC. is a well-known traditional herbal medicine administered for bronchitis and inflammatory diseases. Especially, anti-inflammatory effect of fermented P. grandiflorus (Jacq.) A.DC. extract (FPGE) was higher than that of P. grandiflorus (Jacq.) A.DC. extract. However, toxicological information for FPGE is lacking.

AIM OF THE STUDY

In this study, we establish a toxicological profile for FPGE by testing genotoxicity, acute and 13-week subchronic toxicity.

MATERIALS AND METHODS

FPGE was evaluated with bacterial reverse mutation, chromosome aberration, and micronucleus test. For the acute- and 13-week subchronic toxicity tests, FPGE was administered orally at doses of 0, 750, 1500, and 3000 mg/kg in SD rats.

RESULTS

The results of the genotoxic assays indicated that FPGE induced neither mutagenicity nor clastogenicity. The acute toxicity test showed that FPGE did not affect animal mortality, clinical signs, body weight changes, or microscopic findings at ≤ 3000 mg/kg. The approximate lethal dose (ALD) of FPGE in SD rats was >3000 mg/kg. For the 13-week subchronic toxicity assay, no FPGE dose induced any significant change in mortality, clinical signs, body or organ weight, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings and histopathologic examination in either SD rat sex. The rat no observed adverse effects level (NOAEL) for FPGE was set to 3000 mg/kg.

CONCLUSIONS

The present study empirically demonstrated that FPGE has a safe preclinical profile and indicated that it could be safely integrated into health products for atopic dermatitis treatment.

Safety assessment of subtilisin QK in rats

BACKGROUND

Subtilisin QK is a serine protease in the subtilisin family, and is fermented by Bacillus subtilis QK02. The fibrinolytic activity of subtilisin QK was measured by detecting low molecular weight degradation products using a spectrophotometric method developed by Japan Bio Science Laboratory Co., Ltd. Subtilisin QK powder can maintain its fibrinolytic activity for more than 24 months when it is stored at room temperature and protected from light. Our previous results showed that subtlisin QK directly degraded cross-linked fibrins in the fibrin plate assay and effectively inhibited thrombosis in the mouse thrombus model. The aim of this study was to determine the acute toxicity, potential subchronic toxicity, and safety pharmacology of subtilisin QK in Sprague-Dawley (SD) rats.

METHODS

In the acute toxicity study, a single oral dose of 100,000 FU/kg was administered to 10 female and 10 male SD rats. In the 28-day subchronic toxicity, 60 female and 60 male SD rats were randomly assigned to four experimental groups (daily oral dose of 0, 2500, 7500 and 25,000 FU/kg). In the safety pharmacology study, 20 female and 20 male SD rats were randomly assigned to four experimental groups (single oral dose of 0, 500, 1500 and 5000 FU/kg).

RESULTS

No death occurred and no adverse effects were observed in the acute toxicity study at a dose of 100,000 FU/kg. In the 28-day subchronic toxicity study, several hematological and blood biochemical parameters showed increases or decreases; however, due to the lack of a dose-response relationship, these differences were considered unrelated to treatment. In the safety pharmacology study, no adverse effects were observed on the central nervous of SD rats post-administration up to a dose of 5000 FU/kg subtilisin QK.

CONCLUSION

The results showed that oral consumption of subtilisin QK is of low toxicological concern. No adverse effects were observed at doses of 2500, 7500, and 25,000 FU/kg in the 28-day subchronic toxicity, and the no-observed-adverse-effect level (NOAEL) of subtilisin QK was 25,000 FU/kg.

Toxicological evaluation of S. involucrata culture: Acute, 90-day subchronic and genotoxicity studies

Saussurea involucrata is an endangered plant that is used in traditional Chinese medicine. Through the use of plant cell culture techniques, preparations of Saussurea involucrata (S. involucrata) cell cultures have been developed and used to generate medicinal preparations. There have been few evidence-based analyses of the toxicological effects of S. involucrata culture conducted to date. Here, we conducted the experiments designed to assess the acute, subchronic, and genotoxic toxicological effects of S. involucrata culture. The genotoxic study was assessed through Ames, marrow micronucleus, and sperm malformation assays. The acute toxicity was assessed by orally administering in rats and mice at dose of 7500 mg/kg. Subchronic toxicity studies were then conducted by administering rats at doses of 500, 1000, or 1500 mg/kg for 90 days. No genotoxicity was observed at any tested dose levels, nor was any evidence of acute toxicity detected in treated mice or rats. Similarly, subchronic study of S. involucrata culture administration was not associated with any changes in rat food intake, weight, hematological parameters, organ weight, or organ histology. Then, we determined that the no observed adverse effect level of S. involucrata culture was greater than 1500 mg/kg in our 90-day toxicity study.

Subchronic safety evaluation of hot-water extract from thinned immature mangos (Mangifera indica 'Irwin'): 90-days oral toxicity study in rats

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Thinned immature mango fruits are usually handled as waste.

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Information is limited about the safety of its daily consumption.

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A 90-days toxicity study of its hot-water extract (TIMEx) was conducted in rats.

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TIMEx is safe for daily consumption and its NOAEL is 2500 mg/kg/day.

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Thinned immature mango fruits will be candidate for functional food.

Thinned immature fruit of the mango tree (Mangifera indica ‘Irwin’) are handled as waste. In this study, we conducted a 90-days toxicity study in male and female Sprague Dawley rats to evaluate the safety of a hot-water extract of thinned immature mango fruits (TIMEx) administered by oral gavage at doses of 500, 1000 and 2500 mg/kg body weight/day. Treatment did not result in death or changes in the behavior or external appearance of the animals. No alterations were observed in hematological or serum chemical parameters, urinalysis, food consumption, body weight gain or organ weights at the end of the treatment period, with the exception of higher mean corpuscular volume in male rats that received high doses and lower serum creatine phosphokinase levels in female rats that received medium doses. Under the conditions of this study and based on the toxicological endpoints evaluated, the no-observed-adverse-effect level (NOAEL) for TIMEx was 2500 mg/kg/day. The findings indicate that TIMEx is safe for consumption and should be investigated as a candidate food.

Safety assessment of phytase transgenic maize 11TPY001 by 90-day feeding study in rats

11TPY001 is a transgenic maize that expresses the Aspergillus niger phyA2 gene which could significantly improve phosphorus bioavailability in monogastric animals. The present study was conducted to investigate the potential health effects of phytase transgenic maize 11TPY001 through a 90-day subchronic rodent feeding study. Maize grains from 11TPY001 or its parental counterpart maize OSL963 were incorporated into rodent diets at 12.5%, 25% and 50% concentrations by mass and administered to Sprague-Dawley rats (n = 10/sex/group) for 90 days. An additional control group of rats (n = 10/sex/group) were fed with common maize Zhengdan958 diets at 50% by mass. All formulated diets were nutritionally balanced. Body weights, food intake, hematology, serum chemistry, absolute and relative organ weights were measured, and gross as well as microscopic pathology were examined. Compared with rats fed OSL963 maize and the common maize diet groups, no adverse diet-related differences were observed in rats fed 11TPY001 maize diets with respect to clinical signs of toxicity, body weight/gain, food consumption/efficiency, hematology, clinical chemistry, organ weights, and gross and microscopic pathology. Under the conditions of this study, the results indicated that 11TPY001 did not cause any treatment related adverse effects in rats compared with its non-transgenic parental maize OSL963.

Safety evaluation of BPL9K-4 rice in a subchronic rodent feeding study

In the present study, a new genetically modified rice producing phytase-lactoferricin fusion protein, BPL9K-4, was evaluated for safety in a 90-day rat feeding study. Rats were fed rodent diets formulated with BPL9K-4 rice, and were compared with rats fed diets formulated with its corresponding non-transgenic parental rice 9 K, commercially available non-transgenic rice Weiyou64, and a basal diet. BPL9K-4 and 9 K rice were formulated into diets at concentrations of 15%, 30% and 60%, and Weiyou64 common rice was added to diets at concentration of 60%. AIN93G diet was set as a basal-diet control. Diets of all groups were fed to rats (10/sex/group) for 90 days. Compared with rats in the 9 K, Weiyou64 and the basal-diet group, rats fed the BPL9K-4 diet did not show any treatment-related adverse effects on mortality, body weights, feed consumption, clinical chemistry, hematology, organ weights and gross and microscopic pathology. Under the conditions of this study, the genetically modified BPL9K-4 diets did not cause any toxicologically significant effects in rats following 90 days of dietary administration as compared with rats fed diets with the corresponding non-transgenic control diet and the basal-diet group. The results indicated that BPL9K-4 rice is as safe as its conventional comparators.

Toxicological evaluation of the ketogenic ester bis hexanoyl (R)-1,3-butanediol: Subchronic toxicity in Sprague Dawley rats

Bis-hexanoyl (R)-1,3-butanediol (BH-BD) is novel ketone ester undergoing development as a food ingredient to achieve nutritional ketosis in humans. Male and female Crl:CD(SD) rats were administered BH-BD twice daily at 9000, 12,000 or 15,000 mg/kg/day, by oral gavage in a 90-day toxicity study with 28-day recovery period; and an interim 28-day phase. Test substance-related early deaths occurred in four females at 15,000 mg/kg/day. A dose-dependent increase in acute transient postdose (1-3 h) observations of incoordination at ≥12,000 mg/kg/day and decreased activity at all dose levels were noted in both sexes. Postdose observations were likely associated with peak ketonemia and were considered adverse at 15,000 mg/kg/day. These daily observations decreased over the study without any persistent effects, as determined during weekly pre-dose observations. Adverse histopathological changes included ulceration/erosion in non-glandular stomach at ≥ 12,000 mg/k/day and in glandular stomach at 15,000 mg/kg/day. These histopathological findings were not noted after 28-days of recovery. Due to unlikely human relevance of the rat non-glandular stomach effects for BH-BD and test substance-related mortality at 15,000 mg/kg/day, the no-observed-adverse-effect level (NOAEL) for subchronic toxicity of BH-BD was determined to be 12,000 mg/kg/day.

A 90-day subchronic toxicity study of 5-methyl-2-phenyl-2-hexenal in F344 rats

5-Methyl-2-phenyl-2-hexenal (MPH) has been used as a flavoring agent. In the present study, we performed a subchronic toxicity study in male and female F344 rats with oral administration of MPH by gavage at 0, 8, 24 and 70 mg/kg body weight (BW)/day for 90 days. No mortality or clinical signs were observed during the experimental period. Body weight and food consumption for all treated groups of both sexes were essentially the same as for the respective control groups. Hematologic examination demonstrated significant decreases in monocyte counts for females given 24 and 70 mg/kg BW/day. However, these changes were not substantial and no related histopathological changes were observed, suggesting that these changes were not toxicologically significant. Among organ weights, the absolute and/or relative weights of testes and liver were significantly increased in the 70 mg/kg BW/day groups of males and females, respectively, but no related histopathological changes were observed, suggesting that these changes did not reflect adverse effects. In addition, no treatment-related histopathological changes were observed for any of the tissues examined. Based on the overall data, the no-observed-adverse-effect level (NOAEL) for MPH was determined to be 70 mg/kg BW/day, the highest dose tested, in both male and female rats.

Subchronic toxicity study in rats evaluating herbicide-tolerant soybean DAS-68416-4

A subchronic toxicity study was conducted in Wistar rats to evaluate the potential health effects of genetically modified (GM) herbicide-tolerant soybean DAS-68416-4. Rats were fed with diets containing toasted meal produced from GM soybean engineered with aad-12 and pat genes or containing non-GM soybean at a dose of 30.0, 15.0, or 7.5%,w/w% and 0% (control group) for 90 consecutive days. Animals were evaluated for general behavior, body weight gain, food consumption, food use efficiency, etc. At the middle and end of the study, blood and serum samples were collected for routine and biochemical assays. Internal organs were taken for calculating relative weights and doing histopathological examination. The rats were active and healthy without any abnormal symptoms during the entire study period. No biological differences in hematological or biochemical indices were detected. No histopathological changes were observed. Under the conditions of this study, herbicide-tolerant soybean DAS-68416-4 did not cause any treatment-related effects in Wistar rats following 90 days of dietary administration.

Safety assessment of a novel thermostable phytase

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The toxicity of Phytase TSP a new thermostable phytase was studied.

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No genotoxic or toxic effects were recorded for Phytase TSP.

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The NOAEL for the new Phytase TSP is 1000 mg/kg bw/d.

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The studies support the safety of Phytase TSP as an animal feed additive.

A novel 6-phytase (Phytase TSP, trade name OptiPhos® PLUS) with improved thermostability has been developed for use in animal feed. The safety of the new phytase was evaluated by testing for genotoxicity and subchronic toxicity. In in vitro and in vivo genotoxicity assays Phytase TSP concentrate was not mutagenic and did not induce biologically or statistically significant increases in the frequency of micronucleated polychromatic erythrocytes. In a subchronic toxicity study, male and female rats administered 100, 500 or 1000 mg/kg body weight/day of Phytase TSP concentrate via oral gavage for 90 days had no mortalities, and no treatment-related effects on body weight, food consumption, clinical observations or ophthalmology. Furthermore, there were no changes in haematology, clinical chemistry, urinalysis, gross pathology, organ weights or histopathology that could be attributed to the test article. Several endpoints exhibited statistically significant effects, but none was dose-related or considered to be of toxicological relevance. Based on these results, Phytase TSP concentrate (OptiPhos® PLUS) was not genotoxic and the No Observed Adverse Effect Level (NOAEL) for male and female rats was 1000 mg/kg body weight/day.

Genotoxicity and subchronic toxicity studies of supercritical carbon dioxide and acetone extracts of rosemary

Toxicology studies conducted with oil-soluble rosemary extracts to support authorization as a food additive (antioxidant) in the EU include an Ames test using a supercritical carbon dioxide extract (D74), a full 90-day study using D74 and an acetone extract (F62), and an investigative 90-day study with a 28-day recovery period (using D74 only). D74 was non-mutagenic in the Ames test. In the full 90-day study, where rats (20/sex/group) were either provided control diet or diets containing D74 (300, 600, or 2400 mg/kg) or F62 (3800 mg/kg), liver enlargement and hepatocellular hypertrophy were observed. To determine a mode of action and assess the reversibility of the hepatic effects, an investigative 90-day study was conducted using female rats (10/group receiving control diet or diet containing 2400 mg/kg D74). Liver enlargement was fully reversible after 28 days and microsomal enzyme analysis revealed reversible induction of cytochrome P450 enzymes (CYP2A1, CYP2A2, CYP2C11, CYP2E1, and CYP4A), demonstrating that the hepatic effects were adaptive and of no toxicological concern. Therefore, the highest dietary concentrations were established as the NOAELs. The investigative 90-day study NOAEL (providing 64 mg/kg bw/day carnosol and carnosic acid [the primary antioxidant components]) was used to establish a temporary ADI for rosemary extracts.

In vivo and in vitro safety evaluation of fermented Citrus sunki peel extract: acute and 90-day repeated oral toxicity studies with genotoxicity assessment

Background

Citrus sunki Hort. ex Tanaka peel has been traditionally used as an ingredient in folk medicine due to its therapeutic effects on promotion of splenic health and diuresis as well as relief of gastrointestinal symptoms. Although a growing interest in health-promoting natural products and the development of highly concentrated products have facilitated consumption of C. sunki peel, its safety assessment has not been explored, posing a potential health risk. In this study, we carried out a series of systemic and genetic toxicity tests on fermented C. sunki peel extract (FCPE) to provide the essential information required for safe use in human.

Methods

We conducted acute and 90-day repeated oral toxicity studies in Sprague-Dawley rats to evaluate systemic toxicity, and three genotoxicity assays to measure bacterial mutation reversion, cellular chromosome aberration and in vivo micronucleus formation.

Results

Single oral administration of FCPE did not cause any clinical signs and lethality in all animals, establishing LD50 to be over 2000 mg/kg BW. Repeated administration of up to 2000 mg/kg BW FCPE for 90 days revealed no test substance-related toxicity as demonstrated in analysis of body weight gain, food/water intake, blood, serum biochemistry, organ weight and histopathology, collectively determining that the no-observable-adverse-effect-level of FCPE is over 2000 mg/kg BW. In addition, we detected no mutagenicity and clastogenicity in FCPE at 5000 μg/plate for the in vitro assays and 2000 mg/kg BW for the in vivo micronucleus test.

Conclusion

FCPE did not cause systemic and genetic toxicity in our model systems at the tested dose levels. These results suggest a guideline for safe consumption of C. sunki peel in human.

Genotoxicity and repeated-dose toxicity evaluation of dried Wolffia globosa Mankai

Wolffia is a genus of protein-rich aquatic plants. Mankai, a cultivated strain of Wolffia globosa, contains more than 40 % protein based on dry matter evaluation. Furthermore, Mankai is nutritionally excellent as a food material, and is expected to be applicable to various products as a substitute for animal protein. A battery of toxicological studies was conducted on the dried product of Mankai (Dry Mankai), with the expectation to utilize it as a raw material for food applications. Dry Mankai was not genotoxic in a bacterial reverse mutation test and in vitro micronucleus assay. In the subchronic toxicity study, rats were provided Dry Mankai in the diet at levels of 0 %, 5 %, 10 %, or 20 % (w/w), equivalent to 0, 3.18, 6.49, and 13.16 g/kg/day for males and 0, 3.58, 7.42, and 15.03 g/kg/day for females, respectively. No adverse effects that could be attributable to treatment were observed in clinical observations, body weight, food consumption, ophthalmology, hematology and blood chemistry, urinalysis, and macroscopic and microscopic findings. According to the repeated-dose study in rats, the no observed adverse effect level of Dry Mankai was 20 % (w/w) for both sexes (13.16 and 15.03 g/kg/day for males and females, respectively).

Safety assessment of propyl-propane-thiosulfonate (PTSO): 90-days oral subchronic toxicity study in rats

Propyl-propane-thiosulfonate (PTSO) is one of the main organosulfur compounds present in Allium essentials oil. Different applications in the food sector have been proposed for PTSO, such as food and feed additive and as active packaging. However, the authorization of its use depends on its toxicity profile. Thus, as a part of its safety assessment, in this work a repeated dose 90-day oral toxicity study has been conducted for the first time in rats following the OECD guideline 408. PTSO was administered to groups of 10 male and 10 female rats at dose levels of 0, 14, 28, and 55 mg/kg/day. No clinical signs or mortality and no changes in body weight, food consumption and feed conversion efficiency were detected through the study. Moreover, no treatment-related changes in hematological and biochemical parameters were observed, for either sex or dose groups. The histopathology study performed revealed no differences in organ weights, and no morphological and histopathological changes were observed. Based on these results, the no-observed-adverse-effect level (NOAEL) of PTSO was judged to be ≥ 55 mg/kg/day for both sexes.

barks in rats

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Extract and ethyl acetate fraction of Cassia fistula L. have potent antibacterial activity against resistant bacteria such as Salmonella typhosa.

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Extract and Ethyl acetate fraction of Cassia fistula L. barks revealed the most active in vivo antibacterial activity.

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At 1000 mg/kg dose of extract exposured for 90 days, histological damages were found either in liver or kidney, but after 30 days the abnormality fully were recovered.

Increasing incidence of antibiotic resistance necessitates the development of more potent antibiotics. The aim of this work was to evaluate the antibacterial activity of Cassia fistula L. barks as an alternative agent for resistant pathogenic bacteria. The C. fistula barks were extracted with ethanol, followed by partition of the extract to give n-hexane, ethyl acetate and water fractions. An in vitro antibacterial assay was conducted to evaluate inhibitory activity of the extract and fractions against Salmonella typhosa and Shigella dysenteriae. An in vivo antibacterial activity was examined using S. typhosa-infected mouse models, in which the colony number of S. typhosa were counted from the infected rats’ feces. Assesment on safety of the extract was conducted by a subchronic toxicity test which mainly examined alteration occured in biochemical parameters and hystopatological conditions of livers and kidneys. The results showed that the ethanol extract inhibited the growth of both S. typhosa and S. dysenteriae with the MIC of 0.3125% w/v, and the ethyl acetate fraction with the MIC of 0.625% b/v. In the in vivo antibacterial assay, the extract at three doses decreased the colony number of S. typhosa significantly, and after the fourth to sixth days, the precentage of decrease reached more than 90% by 1000 mg/kg dose. The subchronic toxicity test revealed that after the extract exposured for 90 days, a dose of 1000 mg/kg induced liver and kidney damages histologically, however, it returned to normal condition after 30 days of recovery. The results of this study indicated that the extract of C. fistula L. barks had potent in vivo antibacterial activity against S. typhosa as sample of resistant bacteria, and is safe to be used as a herbal medicine, preferably at a dose lower than 1000 mg/kg.

An evaluation of the genotoxicity and subchronic toxicity of the peel extract of Ponkan cultivar 'Ohta ponkan' (Citrus reticulata Blanco) that is rich in nobiletin and tangeretin with anti-dementia activity

Nobiletin and tangeretin are major components of polymethoxylated flavones in the peels of citrus fruits such as Citrus reticulata. Because nobiletin and tangeretin have attracted attention due to their beneficial health properties, citrus peel extracts, in which they are concentrated, have the potential to serve as a functional food ingredient to prevent diseases. In this study, a series of toxicological studies on the peel extract of Ponkan cultivar 'Ohta ponkan' (Citrus reticulata Blanco), was conducted. No mutagenic activity was observed in a bacterial reverse mutation test, whereas chromosomal aberrations were induced in an in vitro mammalian chromosomal aberration test. No genotoxicity was observed in an in vivo mammalian micronucleus test. In a 90-day study at daily doses of 54, 180, or 540 mg/kg body weight (bw)/day, hyaline droplet nephropathy, which specifically occurs in adult male rats, was observed in males of 540 mg/kg bw/day group. No other adverse effects were observed in the 90-day study. The no adverse effect level in the 90-day study was considered to be 540 mg/kg bw/day for female rats and less than 540 mg/kg bw/day for male rats.

Subchronic toxicological evaluation of Bojungikki-tang water extract: 13-Week oral repeated-dose toxicity study in Crl:CD (SD) rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bojungikki-tang is a traditional herbal medicine used to boost immunity and reduce fatigue. However, there is not enough scientific evidence about its toxicological safety profile to support its continued clinical application.

AIM OF THE STUDY

The objective of this study was to investigate the subchronic toxicity profile of Bojungikki-tang water extract (BITW) in Sprague Dawley rats who were exposed to it in multiple doses and various concentrations.

MATERIALS AND METHODS

BITW was administered to rats orally, once daily at doses of 0, 500, 1000, or 2000 mg/kg/day for 13 weeks. We checked toxicological parameters including general observations, organ/body weights, food consumption, ophthalmological signs, hematological and serum biochemical values, urinalysis values and histopathological findings.

RESULTS

The 13 week repeated oral administration of BITW to rats at doses at doses levels of less than or equal to 2000 mg/kg/day caused no significant toxicological changes and only minor nonsignificant changes.

CONCLUSIONS

Our findings indicate that administration of BITW for up to 13 weeks may be safe and nontoxic, with a no-observed-adverse-effect-level of >2000 mg/kg/day for both male and female rats.

Morning glory seed keeps laxative effect while retains less subchronic toxicity after being fried

ETHNOPHARMACOLOGICAL RELEVANCE

Morning glory seed (MGS), has been widely used in treating constipation especially towards children. Clinically, people usually take fried MGS (MGSF) in formulas to reduce its side effect. However, the safety of MGSF other than MGS has yet to be explored.

OBJECTIVE

The study aimed to reveal the potential mechanisms of using MGSF instead of MGS basing on chemistry, pharmacodynamics and toxicology.

METHODS

The chemical compositions of the extracts of MGS and MGSF were compared using UPLC-Q-TOF/MS method. Simultaneously, to prove the availability and safety of MGSF, we investigated the laxative effect and subchronic toxicity of MGS and MGSF and addressed the mechanism of laxative effect of them.

RESULTS

In this study, less phenolic acids and more fatty acids were detected in MGSF compared with the compounds in MGS. Moreover, we found that MGS group had stronger laxative effect than MGSF group via downregulating the expression of AQP3 protein. As for subchronic toxicity test, the body weights of MGS group were lower than MGSF group. In serum biochemistry and histopathological examinations, MGS group could cause more serious toxicity in liver, kidney and colon than MGSF group with higher values of BUN, Cr, AST and ALP.

CONCLUSION

Based on the findings in this study, MGSF with varied compounds contents could still keep the laxative effect while retain less subchronic toxicity, which emphasized the necessity of processing and provided an insight into the rational use of MGSF in clinical practice.

Biochemical responses and DNA damage induced by herbicide QYR301 in earthworm (Eisenia fetida)

QYR301, a novel herbicidal inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD), has great potential for resistant weed control in paddy fields, but massive use of pesticides may result in toxicity to soil non-target organisms. Thus, this study was designed to assess subchronic toxicity of different doses of QYR301 in artificial soil (0, 0.1, 1.0, 2.5, and 5.0 mg kg^-1) to earthworms (Eisenia fetida) on days 7, 14, 21, and 28 after exposure, using biomarkers of reactive oxygen species (ROS) and malondialdehyde (MDA) contents, activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and glutathione-S-transferase (GST), and DNA damage. The ROS content significantly increased for all treatments on 7 and 14 days then decreased, and recovered to control level for 0.1 and 1.0 mg kg^-1 treatment on day 28. Concerning enzymes activities, QYR301 increased POD, SOD, and GST activities, but inhibited CAT activity. Except for POD activity, SOD, CAT, and GST activities of 0.1 mg kg^-1 group recovered to control level on day 28. Also, the MDA content of 0.1 mg kg^-1 group reached control level on day 28. However, DNA damage was observed for all treatments throughout the experiment and it increased with increasing doses and time except for 5.0 mg kg^-1 treatment on day 28. These results suggested that QYR301 induced excessive ROS production leading to oxidative stress in earthworms, which caused lipid membrane peroxidation and DNA damage ultimately. The findings could provide a theoretical foundation for assessing ecological damage of QYR301 to soils and a guide for future QYR301 applications.

Antihypertensive Effect and Safety Evaluation of Rice Bran Hydrolysates from Sang-Yod Rice

Rice bran hydrolysates contain highly nutritional proteins and beneficial phytochemicals. Sang-Yod rice bran hydrolysates (SRH) extracted from red pigmented rice is a rich source of nutrients and phenolic compounds. The present study evaluated the antihypertensive effect of SRH and its safety in Sprague-Dawley rats. Hypertension was induced in male rats by administration of L-NAME (50 mg/kg/day) in drinking water for three weeks, and the antihypertensive effect of SRH was evaluated. Treatment of SRH (250 or 500 mg/kg) significantly reduced arterial blood pressure and improved hemodynamic parameters. The antihypertensive effect was associated with decreased oxidative stress, suppressed p47^phox NADPH oxidase expression, increased nitric oxide bioavailability and decreased angiotensin II level and ACE activity. The SRH was shown to be safe after feeding male and female rats with a rodent diet containing 1.5% SRH for 90 days. Overall, these findings suggest that SRH is safe and may help to prevent hypertension.

Subchronic feeding toxicity studies of drought-tolerant transgenic wheat MGX11-10 in Wistar Han RCC rats

A subchronic toxicity study were conducted in Wistar Han RCC rats to evaluate the potential health effects of genetically modified (GM), drought-tolerant wheat MGX11-10. Rats were fed a rodent diet formulated with MGX11-10 and were compared with rats fed a diet formulated with its corresponding non-transgenic control Jimai22 and rats fed a basal diet. MGX11-10 and Jimai22 were ground into flour and formulated into diets at concentrations of 16.25, 32.5, or 65%, w/w% and fed to rats (10/sex/group) for 13 weeks. Compared with rats fed Jimai22 and the basal-diet group, no biologically relevant differences were observed in rats fed the GM diet with respect to body weight/gain, food consumption/efficiency, clinical signs, mortality, ophthalmology, clinical pathology (hematology, prothrombin time, urinalysis, clinical chemistry), organ weights, and gross and microscopic pathology. Under the conditions of this study, the MGX11-10 diets did not cause any treatment-related effects in rats following at least 90 days of dietary administration as compared with rats fed diets with the corresponding non-transgenic control diet and the basal-diet group. The MGX11-10 diets are considered equivalent to the diets prepared from conventional comparators. The results demonstrated that MGX11-10 wheat is as safe and wholesome as the corresponding non-transgenic control wheat.

Preclinical safety evaluation of triacylglycerol lipase QLM from Burkholderia ubonensis

Triacylglycerol lipases are well characterized enzymes that catalyze the hydrolysis of fats. They are biotechnologically relevant enzymes and are used in a wide range of practical applications in industry. Lipase produced from Burkholderia ubonensis (strain PL266-QLM) (Lipase QLM) is being investigated for use as a processing aid in multiple food applications and may therefore be present at trace levels in finished food products. A battery of toxicological studies was therefore conducted on Lipase QLM to support its safe use in food. Lipase QLM was not genotoxic or mutagenic in an in vitro bacterial reverse mutation test and chromosome aberration test. Additionally, no test article-related adverse effects were observed in clinical observations, body weight, food consumption, ophthalmology, hematology, blood chemistry, urinalysis, and macroscopic and microscopic findings in a subchronic toxicity study in rats administered Lipase QLM in the diet at levels of 0%, 0.8%, 2%, and 5% Lipase QLM. The no-observed-adverse-effect level was therefore considered to be 5% Lipase QLM in both sexes [3357.2 and 3777.6 mg/kg body weight/day (2756.3 and 3101.4 mg total organic solids/kg body weight/day) in males and females, respectively] under the test conditions, which supports the safety of this ingredient for use in food for human consumption.

Genotoxicity and subchronic toxicological study of a novel ginsenoside derivative 25-OCH3-PPD in beagle dogs

Background

Ginsenosides have been widely used clinically for many years and were regarded as very safe. However, a few researches on the toxicities of these kinds of agents showed that some ginsenosides may have side-effect on the rats or dogs. So it is extremely necessary to further clarify the potential toxicity of ginsenosides. This study was carried out to investigate long-term toxicity and genotoxicity of 25-methoxydammarane-3, 12, 20-triol (25-OCH₃-PPD), a new derivative of ginsenoside, in beagle dogs.

Methods

Twenty-four beagle dogs were divided randomly into four treatment groups and repeatedly orally administered with 25-OCH₃-PPD capsule at 60, 120, and 240 mg/kg/day for 91 consecutive days. Ames, micronucleus, and chromosomal aberration tests were established to analyze the possible genotoxicity of 25-OCH₃-PPD.

Results

There was no 25-OCH₃-PPD–induced systemic toxicity in beagle dogs at any doses. The level of 25-OCH₃-PPD at which no adverse effects were observed was found to be 240 mg/kg/day. The result of Ames test showed that there was no significant increase in the number of revertant colonies of 25-OCH₃-PPD administrated groups compared to the vehicle control group. There were also no significant differences between 25-OCH₃-PPD administrated groups at all dose levels and negative group in the micronucleus test and chromosomal aberration assay.

Conclusion

The highest dose level of 25-OCH₃-PPD at which no adverse effects were observed was found to be 240 mg/kg per day, and it is not a genotoxic agent either in somatic cells or germs cells. 25-OCH₃-PPD is an extremely safe candidate compound for antitumor treatment.

Subchronic toxicity of cerium nitrate by 90-day oral exposure in wistar rats

This study evaluated the subchronic toxicity of cerium nitrate and determined the no observed adverse effect level (NOAEL) in Wistar rats. In accordance with the Organization for Economic Co-operation and Development guidelines, cerium nitrate was orally administered to Wistar rats by gavage at 0, 0.2, 75, 150, and 300 mg/kg bw/day for 90 days, followed by 28 days of recovery period in the 300 mg/kg bw/day and the control groups. The following parameters were evaluated: mortality, abnormalities, body weight, food consumption, hematology, serum biochemistry, urinanalysis, gross necropsy and histopathology. At the end of the treatment, several significant changes were observed in the 300 mg/kg bw/day groups: relatively decreased mean body weight of males, increased LYMPH%, RET% and decreased NEUT%, RBC of the females, increased ALT, AST and decreased ALB, T-Bil, CHO, CK, LDH of males. Significantly decreased T-Bil, CHO, CK and LDH were also observed in males of the 150 mg/kg bw/day group. Pathological examination revealed that the incidences of foreign body granulomatous lesions in lungs were higher in the 150 and 300 mg/kg bw/day groups as compared with the control group. These findings were attributed to unexpected gavage exposure because the granuloma exhibited a bronchiole-derived distribution. Taken together, the NOAEL of cerium nitrate in Wistar rats is set to be 75 mg/kg bw/day in the present study.