Oral Toxicity In Rats Research Articles

2,4-Dinitroanisole (DNAN) (2014).

2,4-dinitroanisole (DNAN) is a warhead explosive currently under investigation as a replacement for TNT in melt-cast insensitive munitions. In animal studies, DNAN is a mild ocular and skin irritant with a significant potential for dermal absorption. It is not a dermal sensitizer. Acute and subacute rat inhalation studies demonstrated minimal toxicity with LC50 and LOAEL endpoints of 2.9 and 150 mg/m3, respectively. In rat oral toxicity studies (14 and 90 days) organ weight and clinical chemistry changes suggested hepatocellular injury and anemia, particularly in females. In males there was evidence of testicular injury at the high-dose level (80 mg/kg/day). The NOAELs for the 14- and 90-day studies were 25 and 5 mg/kg/day, respectively, with a calculated BMDL10 value of 0.93 mg/kg/day. No chronic, carcinogenicity or reproductive/developmental toxicity data were available for DNAN, but a maternal and fetal NOAEL of 5.1 mg/kg/day was inferred. DNAN is considered non-mutagenic and non-genotoxic. It is metabolized in vivo to 2,4-dinitrophenol (DNP), but other details of its metabolism or pharmacokinetics are unknown. There are considerable toxicity data for DNP, a known un-coupler of oxidative phosphorylation among other things, and these data may further inform regarding the safety of DNAN. In humans, DNAN was a component of louse powder (prior to DDT) with no reported safety concerns. However, its handling and use as a munition component presents a potential occupational hazard by both inhalation and dermal routes of exposure. Considering both DNAN and DNP toxicity endpoints, the recommended Workplace Environmental Exposure limit for DNAN is 0.1 mg/m2 (8-h time weighted average).

Acute and Subacute Oral Toxicity Evaluation of Commiphora Campestris Methanolic Stem Bark Extract (CASBMCE) In Mice and Rats

Acute and Subacute Oral Toxicity Evaluation of Commiphora Campestris Methanolic Stem Bark Extract (CASBMCE) In Mice and Rats

Safety evaluation of HOWARU® Restore (Lactobacillus acidophilus NCFM, Lactobacillus paracasei Lpc-37, Bifidobacterium animalis subsp. lactis Bl-04 and B. lactis Bi-07) for antibiotic resistance, genomic risk factors, and acute toxicity

Although probiotic lactobacilli and bifidobacteria are generally considered safe by various regulatory agencies, safety properties, such as absence of transferable antibiotic resistance, must still be determined for each strain prior to market introduction as a probiotic. Safety requirements for probiotics vary regionally and evaluation methods are not standardized, therefore methodologies are often adopted from food ingredients or chemicals to assess microbial safety. Four individual probiotic strains, Lactobacillus acidophilus NCFM®, Lactobacillus paracasei Lpc-37®, Bifidobacterium animalis subsp. lactis strains Bl-04®, and Bi-07®, and their combination (HOWARU® Restore) were examined for antibiotic resistance by broth microdilution culture, toxin genes by PCR and genome mining, and acute oral toxicity in rats. Only B. lactis Bl-04 exhibited antibiotic resistance above a regulated threshold due to a tetW gene previously demonstrated to be non-transferable. Genomic mining did not reveal any bacterial toxin genes known to harm mammalian hosts in any of the strains. The rodent studies did not indicate any evidence of acute toxicity following a dose of 1.7–4.1 × 1012 CFU/kg body weight. Considering a 100-fold safety margin, this corresponds to 1.2–2.8 × 1012 CFU for a 70 kg human. Our findings demonstrate a comprehensive approach of in vitro, in silico, and in vivo safety testing for probiotics.

Development and Acute Oral Toxicity Evaluation of a Dry Extract from Tamarindus Indica L

Development and Acute Oral Toxicity Evaluation of a Dry Extract from Tamarindus Indica L

Acute oral toxicity evaluation of aqueous ethanolic extract of Saccharum munja Roxb. roots in albino mice as per OECD 425 TG.

S. munja roots have been used in ethno medicines for the treatment of different ailments. Despite its beneficial uses no studies on its toxicity potential have been reported. The study was designed to evaluate acute toxic potential of aqueous ethanolic extract of S. munja roots according to OECD TG No. 425. Female mice were divided into two groups (n=5). One group served as control while the other as treated group that received 2000mg/kg b.w. of S. munja roots ethanolic extract orally. Then both groups were observed for 14days. Then the blood samples were collected by cardiac puncture, under chloroform general anesthesia and were subjected to hematological and biochemical analyses. The vital organs of anesthetized animals were preserved for histopathological examination. The the data revealed that LD50 of the extract was greater than 2000mg/kg b.w. There was no significant alteration found in body weight and organ to body mass index. In comparison with control group, there was significant increase in levels of ALT, AST, total proteins, globulin levels, serum urea, cholesterol, triglycerides, LDL, platelet count, MCV, MCH, WBC count and lymphocytes whereas ALP and MCHC levels were reduced significantly. From the data obtained in this study, It can be concluded that though LD50 is greater than 2000mg/kg b.w. but moderate toxicity signs appeared in liver, kidney, lipid profile and CBC also showed blood dyscresias at limit dose.

Acute and Sub-chronic Oral Toxicity Evaluation of Eucalyptus globulus Essential Oil-Water Emulsion in Mice

Background: plants are composed of bioactive chemicals some of which may be toxic. Therefore, scientists advocate for toxicological studies to be carried out in order to ensure the safety of drugs. Accordingly, this study was aimed to assess the possible toxic effects of Eucalyptus glubulus essential oil- water emulsion after oral administration in mice. Methods: The essential oil used in this study was obtained by extraction of the fresh leaves of E. glubulus through hydro-distillation technique. In the acute toxicity study, the mice placed in the seven treatment groups were administered with randomly selected 0.5 ml/kg initial dose up to 3.5 ml/kg body weight spaced by 0.5 ml/kg. The control animals received vehicle. All animals were gavaged the designated dose once and observed for the next two weeks. In the sub-chronic study, a control and two treatment groups, each containing twelve animals were used. Based on the findings of acute toxicity study, the two treatment groups were received 1.5 and 2.0 ml/kg body weight test doses respectively for three months in 24 hours interval. At the end study period, blood samples were taken by cardiac puncture and then, all animals were sacrificed and the vital organs were collected and processed for histopathological examination. Results: In the acute toxicity study, some toxicity signs and deaths of mice were recorded only at doses higher than 2.0 ml/kg body weight. 1 out of 6 mice in a group treated with 3.0 ml/kg and, 4 out of 6 animals in a group treated with 3.5 ml/kg body weight test doses of the emulsion were died following the administration. Therefore, the oral route LD50 of the emulsion falls between 3 ml/kg and 3.5 ml/kg. In the sub-chronic treatment, no death was recorded, and there was no statistically significant (p>0.05) change in the body weight, evaluated hematological and biochemical parameters of blood. However, minor pathological changes like; pyknosis and vacuolations of hepatocytes in some liver sections, and perivascular lymphocytic infiltrations and hyaline casts in renal tubules of some kidney sections, were observed in mice treated with 2.0 ml/kg body weight test dose. Conclusions and recommendations: The emulsion at relatively lower doses does not produce obvious toxic effects after acute and prolonged oral administration in mice. However, further investigation is needed to confirm this.

Toxicological Studies of Rasasindura, an Ayurvedic Formulation

Rasasindura is a unique, Ayurvedic mercurial preparation widely used by practitioners. Thi investigation is an attempt to perform acute and chronic oral toxicity evaluation of Rasasindura along with an adjuvant Guduchi Ghana (solidified aqueous extract of Tinospora cordifolia Will.) in rats. Oral acute toxicity study of test drug was carried at the limit dose of 2000 mg/kg orally in rats. For chronic toxicity, Rasasindura with adjuvant was administered at therapeutic equivalent dose (45 mg/kg, orally), therapeutic equivalent dose×5 (225 mg/kg, orally), therapeutic equivalent dose×10 (450 mg/kg, orally) for 90 days and an additional recovery group of therapeutic equivalent dose×10 for 30-day observation after the treatment period. Acute toxicity result showed that drug did not produce any signs and symptoms of toxicity or mortality up to an oral dose of 2000 mg/kg in rats. Chronic toxicity results showed that Rasasindura, even at a level as high as therapeutic equivalent dose×10 level, had no significant effect whatsoever on the ponderal and hematological parameters. Although the drug produced mild to moderate adverse changes (in kidney, liver, intestine, and stomach) at therapeutic equivalent dose×10 dose level, equivalent of which are unlikely to be ever employed in a clinical trial. The observed changes were not seen at the lower dose levels as well as in the recovery study. Hence, it is suggested that the Rasasindura, along with the adjuvant prepared as per the customary method, is safe for consumption at the therapeutic dose level.

상지추출물의 단회/반복투여 독성 및 복귀돌연변이능 평가

상지추출물의 단회/반복투여 독성 및 복귀돌연변이능 평가

Safety of micronized palmitoylethanolamide (microPEA): lack of toxicity and genotoxic potential.

Palmitoylethanolamide (PEA) is a natural fatty acid amide found in a variety of foods, which was initially identified in egg yolk. MicroPEA of defined particle size (0.5–10 μm) was evaluated for mutagenicity in Salmonella typhimurium, for clastogenicity/aneuploidy in cultured human lymphocytes, and for acute and subchronic rodent toxicity in the rat, following standard OECD test protocols, in accordance with Good Laboratory Practice (GLP). PEA did not induce mutations in the bacterial assay using strains TA1535, TA97a, TA98, TA100, and TA102, with or without metabolic activation, in either the plate incorporation or liquid preincubation methods. Similarly, PEA did not induce genotoxic effects in human cells treated for 3 or 24 h without metabolic activation, or for 3 h with metabolic activation. PEA was found to have an LD50 greater than the limit dose of 2000 mg/kg body weight (bw), using the OECD Acute Oral Up and Down Procedure. Doses for the 90‐day rat oral toxicity study were based on results from the preliminary 14‐day study, that is, 250, 500, and 1000 mg/kg bw/day. The No Effect Level (NOEL) in both subchronic studies was the highest dose tested.

Photoprotective effect and acute oral systemic toxicity evaluation of the novel heterocyclic compound LQFM048

The new heterocyclic derivative LQFM048 (3) (2,4,6-tris ((E)-ethyl 2-cyano-3-(4-hydroxy-3-methoxyphenyl)acrylate)-1,3,5-triazine) was originally designed through the molecular hybridization strategy from Uvinul® T 150 (1) and (E)-ethyl 2-cyano-3-(4hydroxy-3-methoxyphenyl)acrylate (2) sunscreens, using green chemistry approach. This compound was obtained in global yields (80%) and showed an interesting redox potential. In addition, it is thermally stable up to temperatures around 250°C. It was observed that LQFM048 (3) showed a low degradation after 150min of sunlight exposure at 39°C, whereas the extreme radiation conditions induced a considerable photodegradation of the LQFM048 (3), especially when irradiated by VIS and VIS+UVA. During the determination of sun protection factor, LQFM048 (3) showed interesting results, specially as in association with other photoprotective compounds and commercial sunscreen. Additionally, the compound (3) did not promote cytotoxicity for 3T3 fibroblasts. Moreover, it was not able to trigger acute oral systemic toxicity in mice, being classified as a compound with low acute toxicity hazard (2.000mg/kg>LD50<5.000mg/kg). Therefore, this compound synthesized using green chemistry approach is promising showing potential to development of a new sunscreen product with advantage of presenting redox potential, indicating antioxidant properties.

Safety evaluation of AB-LIFE® (Lactobacillus plantarum CECT 7527, 7528 and 7529): Antibiotic resistance and 90-day repeated-dose study in rats

AB-LIFE® is a probiotic product consisting of equal parts of three strains of Lactobacillus plantarum (CECT 7527, 7528, and 7529) blended with inert excipients. Whole genome sequencing was performed on each of the three strains. Antibiotic resistance was evaluated by genomic mining for resistance genes, and assessment for transferability. No risk of transfer potential was identified for any antibiotic resistance genes in the three strains. AB-LIFE® was evaluated for potential subchronic oral toxicity in rats, with dosages of 300 and 1000 mg/kg BW/day (equivalent to 5.55 × 1010 and 1.85 × 1011 CFU/kg BW/day). Survival of the three test strains through the gastrointestinal tract was supported by fecal analysis. No adverse effects were identified with respect to in-life parameters, clinical or anatomic pathology, translocation, or fecal chemical analyses. The no-observed-adverse-effect level (NOAEL) for AB-LIFE® in male and female rats was 1000 mg/kg BW/day (1.85 × 1011 CFU of AB-LIFE®/kg BW/day), the highest dose level evaluated. These results, in conjunction with a previous acute toxicity study in rats, support the conclusion that AB-LIFE® is safe for human consumption.

Oral subchronic toxicity evaluation of a novel antitumor agent 25-methoxydammarane-3, 12, 20-triol from Panax notoginseng in Sprague–Dawley rats

Panax notoginseng and its main active ingredients ginsenosides have long been used as medicines and food additives in China. Comparing with the extensive uses and active researches of P. notoginseng and its products, the side effect and probable toxicity were rare. 25-Methoxydammarane-3,12,20-triol (25-OCH3-PPD), a novel dammarane-type triterpene sapogenin that was first isolated from the extract of P. notoginseng, was proven to have strong antitumor activities against prostate cancer, breast cancer and lung cancer. The aim of the present study was to investigate the potential subchronic toxicity of 25-OCH3-PPD after it was repeatedly orally administered to Sprague–Dawley rats (5/sex/group/each time-point) at dose levels of 0, 150, 300 or 600 mg/kg/day for 13 weeks and 4-week recovery. No mortality and treatment-related toxicity effects were observed as a result of the administration of 25-OCH3-PPD at any dose level (150, 300 and 600 mg/kg) for 92 consecutive days. Although there were some statistical changes, such as increased weights in female rats and decreased organ weights and coefficients of the liver, spleen, kidney, and adrenal gland compared with the control group at the corresponding time, the autopsy and histopathological examination of the target organs did not show any abnormal responses. As a result, 25-OCH3-PPD was well tolerated by SD rat at doses of up to 600 mg/kg and that it is a potential candidate for therapeutic use.

Subchronic oral toxicity evaluation of ethanolic whole plant extract of Eleucine indica on haematological and biochemical indices in Wistar albino rats

Objective: To evaluate the effect of ingestion of ethanolic whole plant extract of Eleucine indica on haematological and biochemical parameters of Wistar albino rats. Methods: Subchronic toxicity study was carried out by oral administration of different doses (200, 400 and 600 mg/kg body weight) of the extract on alternate-day basis to different groups of rats for 28 days. The animals were subsequently sacrificed and blood samples were collected by cardiac puncture for haematological and biochemical analyses. Results: Haematological indices were preserved and the extract showed significant (P < 0.01-0.001) haemostatic potentials. There was significant reduction (P < 0.05-0.001) in total bilirubin, aspartate aminotransferase (P < 0.001), alanine transaminase (P < 0.05), alkaline phosphatase (P < 0.001) and blood glucose (P < 0.001) compared to control. The level of total protein increased significantly (P < 0.05-0.001). Kidney functions were, however, intact. Conclusions: The results obtained indicated that ingestion of Eleucine indica whole plant extract for a long period of time reduces both bleeding and clotting times, reduces blood sugar and shows no apparent toxic effect on liver and kidneys. The results of this study may be useful as a basis for clinical trials in humans.

Toxicological evaluation of genotoxicity and 28-day oral toxicity study on freeze-dried powder of Allomyrina dichotoma larvae

Edible insects have noteworthy potential as an alternative food material because of their economical efficiency and nutritional value. This study was conducted to evaluate toxicological effects on in vitro and in vivo experiments for Allomyrina dichotoma (A. dichotoma), whose larvae are known for containing biologically valuable functions. The present study included testings for genotoxicity and 28-day repeated oral toxicity. The genotoxic potential was evaluated by a standard battery test. To evaluate the repeated dose toxicity, the freeze-dried powder of A. dichotoma larvae was orally administered to Sprague–Dawley (SD) rats at dose levels of 0, 250, 850 and 2500mg/kg body weight per day for 28days. The powder exhibited no mutagenic or clastogenic effects based on the results of in vitro and in vivo genotoxicity tests. Also, there were no treatment-related changes or findings on the repeated oral toxicity in rats after 28days oral administration. In conclusion, the results of these experiments suggest that the NOAEL (No Observed Adverse Effect Level) of the freeze-dried powder from A. dichotoma larvae was determined to be 2500mg/kg/day or more in both sexes of SD rats.

Acute and sub-chronic (28 days) oral toxicity evaluation of tincture Baccharis trimera (Less) Backer in male and female rodent animals

The infusion of Baccharis trimera (Less) DC, popularly known as “carqueja” (broom), is popularly used in the treatment of hepatic and digestive problems. In this study, we evaluated the acute and sub-chronic oral toxicities of B. trimera tincture on male and female Wistar rats according to Organization for Economic Cooperation and Development (OECD, guidelines 423 e 407, respectively). The B. trimera tincture was administered by oral gavage in a single dose (2000 mg/kg) in doses of 100, 200 and 400 mg/kg daily for 28 days. Blood was collected to analyze hematological and biochemical parameters. Kidneys and liver were homogenized to determine lipid peroxidation and δ-aminolevulinate dehydratase (δ-ALA-D) and catalase (CAT) enzyme activities. In acute treatment, tincture did not induce any signs of toxicity or mortality. Daily oral administration produced no significant changes in the hematological and biochemical parameters, except for the hepatic enzymes alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) that showed a reduction in both sexes. Moreover, the B. trimera tincture did not increase lipid peroxidation or affected ALA-D and CAT activities. In conclusion, the tincture of B. trimera may be considered relatively safe in this protocol.

Acute and Subacute Oral Toxicity Evaluation of Crude Antifungal Compounds Produced by Lactobacillus plantarum HD1 in Rats.

The aim of this study was to investigate the acute and subacute oral toxicity of crude antifungal compounds produced by Lactobacillus plantarum HD1 in Sprague-Dawley rats. In the acute toxicity study, the crude antifungal compounds (0.625, 1.25, 2.5, and 5.0 g/kg) did not produce mortality, significant changes in general behavior, or changes in the gross appearance of the organs. In the subacute toxicity study, the crude antifungal compounds were administered orally to rats at doses of 0, 0.5, 1.0, and 2.0 g/kg daily for 28 days. There were no test article-related deaths, abnormal clinical signs, or body weight changes. The study also showed no significant differences between the control and treated groups in hematological and serum biochemical parameters, histopathological examination, or any other findings. These results suggest that acute or subacute oral administration of crude antifungal compounds from L. plantarum HD1 is not toxic in rats.

Acute Toxicity Prediction in Multiple Species by Leveraging Mechanistic ToxCast Mitochondrial Inhibition Data and Simulation of Oral Bioavailability

There is great interest in assessing the in vivo toxicity of chemicals using nonanimal alternatives. However, acute mammalian toxicity is not adequately predicted by current in silico or in vitro approaches. Mechanisms of acute toxicity are likely conserved across invertebrate, aquatic, and mammalian species, suggesting that dose-response concordance would be high and in vitro mechanistic data could predict responses in multiple species under conditions of similar bioavailability. We tested this hypothesis by comparing acute toxicity between rat, daphnia, and fish and by comparing their respective acute data to inhibition of mitochondria membrane potential (MMP) using U.S. Environmental Protection Agency ToxCast in vitro high-throughput screening data. Logarithmic scatter plots of acute toxicity data showed a clear relationship between fish, daphnia, and intravenous rat but not oral rat data. Similar plots versus MMP showed a well-delineated upper boundary for fish, daphnia, and intravenous data but were scattered without an upper boundary for rat oral data. Adjustments of acute oral rat toxicity values by simulating fractional absorption and CYP-based metabolism as well as removing compounds with hydrolyzable linkages or flagged as substrates for glucuronidation delineated an upper boundary for rat oral toxicity versus MMP. Mitochondrial inhibition at low concentrations predicted highly acutely toxic chemicals for fish and daphnia but not the rat where toxicity was often attenuated. This use of a single high-throughput screening assay to predict acute toxicity in multiple species represents a milestone and highlights the promise of such approaches but also the need for refined tools to address systemic bioavailability and the impact of limited absorption and first pass metabolism.

Toxicity and Biokinetics of Colloidal Gold Nanoparticles.

Gold nanoparticles (Au-NPs) have promising potential for diverse biological application, but it has not been completely determined whether Au-NP has potential toxicity in vitro and in vivo. In the present study, toxicity of Au-NP was evaluated in human intestinal cells as well as in rats after 14-day repeated oral administration. Biokinetic study was also performed to assess oral absorption and tissue distribution. The results demonstrated that Au-NP did not cause cytotoxic effects on cells after 24 h exposure in terms of inhibition of cell proliferation, membrane damage, and oxidative stress. However, when a small number of cells were exposed to Au-NP for seven days, colony forming ability remarkably decreased by Au-NP treatment, suggesting its potential toxicity after long-term exposure at high concentration. Biokinetic study revealed that Au-NP slowly entered the blood stream and slightly accumulated only in kidney after oral administration to rats. Whereas, orally administered Au ions were rapidly absorbed, and then distributed in kidney, liver, lung, and spleen at high levels, suggesting that the biological fate of Au-NP is primarily in nanoparticulate form, not in ionic Au. Fourteen-day repeated oral toxicity evaluation showed that Au-NP did not cause severe toxicity in rats based on histopathological, hematological, and serum biochemical analysis.

Acute and 28-day sub-acute oral toxicity evaluation of two dietary bamboo charcoal powders in Sprague-Dawley rats.

No data were available on the acute oral toxicity, short-term oral toxicity of vegetable carbon in animals. This study was designed to evaluate the safety of two commercially available dietary bamboo charcoal powders (BCP1 and BCP2). The size distribution of the two powders was determined by a Mastersizer 2000 laser particle size analyzer prior to the in vivo safety studies. For the acute toxicity study, a single dose of 11.24 g/kg body weight of BCP1 and BCP2 was given once orally to healthy Sprague-Dawley (SD) rats. Mortality and clinical symptoms were observed and recorded for the first 30 min after treatment, at 4 h post-administration, and then at least once daily for 14 days after administration. In the repeated dose 28-day oral toxicity study, BCP1 and BCP2 were administered orally at doses of 2.81, 5.62, and 11.24 g/kg body weight for 28 days to SD rats. Animals were sacrificed and organs and blood samples were analyzed. Results showed that both BCP1 and BCP2 were micro-sized and various in size. In the acute toxicity and the repeated dose 28-day oral toxicity studies, BCP caused neither mortality nor visible signs of toxicity in rats. No significant differences were found in the relative organ weights or in biochemical parameters in BCP treated groups compared to a control group. No treatment-related histological changes were observed in the organs of these animals. Based on these data, it is concluded that the median lethal dose (LD50) of BCP for both male and female rats is more than 11.24 g/kg body weight and the no-observed-adverse-effect level (NOAEL) is >11.24 g/kg body weight for 28 days.

A 28-day oral toxicity evaluation of small interfering RNAs and a long double-stranded RNA targeting vacuolar ATPase in mice

New biotechnology-derived crop traits have been developed utilizing the natural process of RNA interference (RNAi). However, plant-produced double stranded RNAs (dsRNAs) are not known to present a hazard to mammals because numerous biological barriers limit uptake and potential for activity. To evaluate this experimentally, dsRNA sequences matching the mouse vATPase gene (an established target for control of corn rootworms) were evaluated in a 28-day toxicity study with mice. Test groups were orally gavaged with escalating doses of either a pool of four 21-mer vATPase small interfering RNAs (siRNAs) or a 218-base pair vATPase dsRNA. There were no treatment-related effects on body weight, food consumption, clinical observations, clinical chemistry, hematology, gross pathology, or histopathology endpoints. The highest dose levels tested were considered to be the no observed adverse effect levels (NOAELs) for the 21-mer siRNAs (48mg/kg/day) and the 218bp dsRNA (64mg/kg/day). As an additional exploratory endpoint, vATPase gene expression, was evaluated in selected gastrointestinal tract and systemic tissues. The results of this assay did not indicate treatment-related suppression of vATPase. The results of this study indicate that orally ingested dsRNAs, even those targeting a gene in the test species, do not produce adverse health effects in mammals.