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.

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.

Subchronic oral exposure of tungsten induces myofibroblast transformation and various markers of kidney fibrosis.

Tungsten is a naturally occurring transition element used in a broad range of applications. As a result of its extensive use, we are increasingly exposed to tungsten from our environment, including potable water, since tungsten can become bioaccessible in ground sources. The kidneys are particularly susceptible to tungsten exposure as this is the main site for tungsten excretion. In this study, we investigated the prolonged effects of tungsten on the kidneys and how this may impact injury and function. When mice were exposed to tungsten in their drinking water for 1 mo, kidney function had not significantly changed. Following 3-mo exposure, mice were presented with deterioration in kidney function as determined by serum and urine creatinine levels. During 3 mo of tungsten exposure, murine kidneys demonstrated significant increases in the myofibroblast marker α-smooth muscle actin (αSMA) and extracellular matrix products: fibronectin, collagen, and matricellular proteins. In addition, Masson's trichrome and hematoxylin-eosin (H&E) staining revealed an increase in fibrotic tissue and vacuolization of tubular epithelial cells, respectively, from kidneys of tungsten-treated mice, indicative of renal injury. In vitro treatment of kidney fibroblasts with tungsten led to increased proliferation and upregulation of transforming growth factor ß1 (TGFß1), which was consistent with the appearance of fibroblast-to-myofibroblast transition (FMT) markers. Our data suggest that continuous exposure to tungsten impairs kidney function that may lead to the development of chronic kidney disease (CKD).

Lung Surfactant Decreases Biochemical Alterations and Oxidative Stress Induced by a Sub-Toxic Concentration of Carbon Nanoparticles in Alveolar Epithelial and Microglial Cells.

Carbon-based nanomaterials are nowadays attracting lots of attention, in particular in the biomedical field, where they find a wide spectrum of applications, including, just to name a few, the drug delivery to specific tumor cells and the improvement of non-invasive imaging methods. Nanoparticles inhaled during breathing accumulate in the lung alveoli, where they interact and are covered with lung surfactants. We recently demonstrated that an apparently non-toxic concentration of engineered carbon nanodiamonds (ECNs) is able to induce oxidative/nitrosative stress, imbalance of energy metabolism, and mitochondrial dysfunction in microglial and alveolar basal epithelial cells. Therefore, the complete understanding of their "real" biosafety, along with their possible combination with other molecules mimicking the in vivo milieu, possibly allowing the modulation of their side effects becomes of utmost importance. Based on the above, the focus of the present work was to investigate whether the cellular alterations induced by an apparently non-toxic concentration of ECNs could be counteracted by their incorporation into a synthetic lung surfactant (DPPC:POPG in 7:3 molar ratio). By using two different cell lines (alveolar (A549) and microglial (BV-2)), we were able to show that the presence of lung surfactant decreased the production of ECNs-induced nitric oxide, total reactive oxygen species, and malondialdehyde, as well as counteracted reduced glutathione depletion (A549 cells only), ameliorated cell energy status (ATP and total pool of nicotinic coenzymes), and improved mitochondrial phosphorylating capacity. Overall, our results on alveolar basal epithelial and microglial cell lines clearly depict the benefits coming from the incorporation of carbon nanoparticles into a lung surfactant (mimicking its in vivo lipid composition), creating the basis for the investigation of this combination in vivo.

Dermal toxicity, dermal irritation, and delayed contact sensitization evaluation of oil body linked oleosin-hEGF microgel emulsion via transdermal drug delivery for wound healing.

Objective: The expression of therapeutic proteins in plant oil body bioreactors has attracted much attention. But its safety is not yet clear. This article determines the risk of safety after using the drug. Methods: The oil body-linked oleosin-hEGF microgel emulsion (OBEME) was prepared by mixing the xanthan gum with suitable concentrations in an appropriate proportion. Skin irritation and sensitization reaction were investigated in rats and guinea pigs using OBEME as test article.Results: The OBEME did not produce dermal erythema/eschar or oedema responses. The dermal subacute and subchronic toxicity of OBEME were evaluated in accordance with OECD guidelines. Compared with the control group, the basic physical signs, such as weight, feed, drinking, excretion, and behaviour of experimental animals, were not abnormal. In addition, no abnormality was found in haematological parameters, biochemical indexes, relative organ weight, and histopathological observation of organs, and there was no significant difference compared with normal saline treatment group. Therefore, we conclude that OBEME has no toxic effects and is safe and reliable to be used for topical application.

Incorporating lines of evidence from New Approach Methodologies (NAMs) to reduce uncertainties in a category based read-across: A case study for repeated dose toxicity.

A group of triazole compounds was selected to investigate the confidence that may be associated with read-across of a complex data gap: repeated dose toxicity. The read-across was evaluated using Assessment Elements (AEs) from the European Chemicals Agency's (ECHA's) Read-Across Assessment Framework (RAAF), alongside appraisal of associated uncertainties. Following an initial read-across based on chemical structure and properties, uncertainties were reduced by the integration of data streams such as those from New Approach Methodologies (NAM) and other existing data. In addition, addressing the findings of the ECHA RAAF framework, complemented with specific questions concerning uncertainties, increased the confidence that can be placed in read-across. Although a data rich group of compounds with a strong mechanistic basis was analysed, it was clearly demonstrated that NAM data available from publicly available resources could be applied to support read-across. It is acknowledged that most read-across studies will not be so data rich or mechanistically robust, therefore some targeted experimentation may be required to fill the data gaps. In this sense, NAMs should constitute new experimental tests performed with the specific goal of reducing the uncertainties and demonstrating the read-across hypothesis.

A 13-week subchronic toxicity study of a Dioscorea Rhizome water extract in rats.

Dioscorea Rhizome is widely used as a traditional herbal medicine to treat asthma, diarrhea, cough, bronchitis, spermatorrhea, leukorrhea, and rheumatoid arthritis. This study investigated the potential subchronic toxicity of a D. Rhizome water extract (DRWE) after repeated oral administration at 0, 800, 2000, and 5000 mg/kg/day in rats for 13 weeks. During the study period, clinical signs, mortality, body weight, food consumption, water consumption, urinalysis, ophthalmoscopy, hematology, serum biochemistry, gross pathology, organ weights, and histopathology were examined. The 13-week repeated oral administration of DRWE to rats resulted in an increased incidence of zona glomerulosa hypertrophy and hyperplasia in the adrenal gland at dose levels of ≥2000 mg/kg/day in both sexes. However, these findings are considered as non-adverse adaptive changes because of minimal histological changes in the lesions, which were not accompanied by any corresponding alterations in serum electrolytes and adrenal gland weight. No treatment-related adverse effects on clinical signs, body weight, food and water consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, and organ weights were observed at any dose tested. Under the present experimental conditions, the no-observed-adverse-effect level of the DRWE was considered to be 5000 mg/kg/day in both sexes, and no target organs were identified.

Sphaeranthus senegalensis DC: Evaluation of chemical constituents, oral safety, gastroprotective activity, and mechanism of action of its hydroethanolic extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Sphaeranthus senegalensis DC is a seasonal herb with a spicy smell that grows wild in wet grounds of tropical Africa and Asia. The plant is used in folk medicine for the treatment of various diseases; that includes its use to treat gastric ulcers. AIM OF THE STUDY: This study aimed to investigate the chemical constituents of the hydroethanolic extract of Sphaeranthus senegalensis DC and evaluate its oral safety, gastroprotective activity, and mechanisms of action using laboratory models in rats and mice. MATERIALS AND METHODS: Hydroethanolic extract (70%) of the powdered whole dried material was prepared, and chemical constituents of the resultant extract (denoted HESs) standardized using the high-performance liquid chromatography (HPLC) method. The safety profile of HESs was assessed using 2000 mg/kg, oral (p.o.) for Hippocratic screening in mice, and 800 mg/kg, p.o. for 28 days subchronic toxicity assay in rats. The gastroprotective effect of HESs (25, 100, and 400 mg/kg, p.o.) was investigated using acidified ethanol, piroxicam, water immobilization stress, and acetic acid-induced ulcer models. The gastroprotective mechanisms of HESs were evaluated using its effect on gastric mucus protection, nitric oxide modulation, gastric juice secretory parameters, catalase and myeloperoxidase activities. Histological analysis of the stomach tissues was also carried out. RESULTS: The HPLC analysis indicated the presence of 25.94% phenolics (gallic acid, caffeic acid, and ferulic acid) and 14.53% flavonoids (rutin, morin, luteolin, quercetin, and apigenin). Hippocratic screening and the 28 days subchronic study indicated that HESs is generally safe. Result shows that oral administration of HESs (25, 100 and 400 mg/kg) alleviated the severity of the gastric ulcers induced by acidified ethanol by 35.65% (p < 0.05), 48.70% (p < 0.05) and 78.02% (p < 0.001) respectively; exhibited gastroprotective effect against the gastric lesions induced by piroxicam by 37.97% (p < 0.05), 53.27% (p < 0.05) and 76.23% (p < 0.001) respectively; and decreased the severity of the water immobilization stress-induced gastric ulcers by 32.43% (p < 0.05), 55.26% (p < 0.01) and 74.05% (p < 0.001) respectively, when compared to the vehicle control group. The mechanisms of action assays indicated that the gastroprotective activity was mediated mainly through gastroprotection, antisecretory, and antioxidant activities. Histological analysis showed it inhibited epithelial cell loss, vascular damage, and leucocyte infiltration. CONCLUSION: HESs contains useful phytochemicals, is safe, and exhibited significant gastroprotective action. The results provided justification for its claim in the treatment of gastric ulcers and its evaluation for potential application as a gastroprotective agent.

A 26-week toxicological study of Xuezhikang (XZK), red yeast rice extract, in Beagle dogs with a 4-week recovery period.

Xuezhikang (XZK) is an extract derived from red yeast rice that is commonly used to treat cardiovascular conditions as a traditional Chinese medicine, both within China and globally. Genotoxicity, acute toxicity, and a 26-week toxicity study in rat have been reported in our previous publication. The present study was designed to assess the long-term safety of XZK when administered orally to dogs. Dogs were treated with encapsulated XZK at a maximum dose of 2000 mg/kg followed by 1000 mg/kg and 500 mg/kg (n = 6/sex/group) for this 26-week oral toxicity study. Control animals were given an empty capsule. Treated animals were then monitored through measurements of body weight, body temperature, food intake, ophthalmic and electrocardiogram examinations, general clinical observations, mortality rates, and clinical and anatomic pathological findings. Additionally, blood samples were collected and used to conduct hematological and biochemical analysis. Several abnormalities were found in all groups including: fecal abnormalities (including mucoid, poorly formed, or liquid feces). Moreover, reduced CHOL and TRIG values were seen in all XZK groups (p < 0.05), increased WBC and NEUT levels in 500 mg/kg group (males only, p < 0.05), and elevated AST, ALT, and ALP activities in 2000 mg/kg group (p < 0.05). These changes were resolved in the recovery period. The results indicated that XZK may temporarily impact the liver enzyme levels, but were not considered adverse effects. These findings yielded a NOAEL for XZK in dogs of 2000 mg/kg.

Weight of evidence and human relevance evaluation of the benfluralin mode of action in rodents (Part I): Liver carcinogenesis.

Benfluralin, an herbicide of the dinitroaniline class used in weed control, was first registered in the United States in 1970. Increased incidence of liver tumors was observed in the 2 year dietary carcinogenicity studies. A review of the toxicology database provides evidence that the mode of action (MOA) of benfluralin responsible for hepatocellular adenoma and carcinoma in rodents depends on activation of the constitutive androstane (CAR)/pregnane X (PXR) receptors, that triggers enzyme induction and altered gene expression leading to hepatocyte proliferation. After prolonged exposures at high dose levels, altered hepatic foci and liver tumors are observed. This hepatocarcinogenic MOA has been described in rodents following long-term dietary exposures to other CAR/PXR activator chemicals, such as phenobarbital, and is generally considered as non-relevant in humans due to differences between human and rodent responses. We analyzed the existing and newly acquired toxicology data to establish that the hepatocarcinogenic MOA of benfluralin in rodents includes the same key events previously described in the rodent MOA of phenobarbital. A weight of evidence approach was taken to establish temporal and dose-related concordance of the causal key events supporting the conclusion that rodent liver carcinogenicity of benfluralin is unlikely to be relevant for human cancer risk.

Weight of Evidence and Human Relevance Evaluation of the Benfluralin Mode of Action in Rats (Part II): Thyroid carcinogenesis.

Benfluralin is an herbicide of the dinitroaniline class used to control grasses and weeds. In a 2 year dietary study in rats, benfluralin increased incidences of thyroid follicular adenoma and carcinoma at high dietary concentrations (≥2500 ppm). The benfluralin toxicology database suggests the mode of action (MOA) is initiated by induction of liver metabolizing enzymes, particularly thyroid hormone specific UGTs, a major pathway for T4 clearance in rats. As reported with phenobarbital, this effect triggers negative feedback regulation, increasing thyroid stimulating hormone (TSH) release into circulating blood. When sustained over time, this leads to thyroid changes such as follicular hypertrophy, hyperplasia and thyroid follicular tumors with chronic exposures. The described MOA was previously established in rat studies with various chemical activators of xenobiotic receptors in the liver. It is generally considered as non-relevant in humans, due to differences between humans and rats in T4 turnover and susceptibility to this carcinogenic MOA. A structured methodology based on the IPCS/MOA/Human Relevance framework was used in the evaluation of available benfluralin data, and the conclusion was determined that the carcinogenic potential of benfluralin in the thyroid is not relevant in humans.

Incorporation of in vitro techniques for botanicals dietary supplement safety assessment - Towards evaluation of developmental and reproductive toxicity (DART).

As complex mixtures, botanicals present unique challenges when assessing safe use, particularly when endpoint gaps exist that cannot be fully resolved by existing toxicological literature. Here we explore in vitro gene expression as well receptor binding and enzyme activity as alternative assays to inform on developmental and reproductive toxicity (DART) relevant modes of action, since DART data gaps are common for botanicals. Specifically, botanicals suspected to have DART effects, in addition to those with a significant history of use, were tested in these assays. Gene expression changes in a number of different cell types were analysed using the connectivity mapping approach (CMap) to identify modes of action through a functional read across approach. Taken together with ligand affinity data obtained using a set of molecular targets customised towards known DART relevant modes of action, it was possible to inform DART risk using functional analogues, potency comparisons and a margin of internal exposure approach.

Cadmium-Induced Testicular Toxicity in Mice: Subacute and Subchronic Route-Dependent Effects.

This study aimed to compare Cd exposure by intraperitoneal (i.p.) and oral routes, evaluating the testicular subacute and subchronic effects. Adult male mice were separated into three groups subdivided according to the experimental period (7 and 42 days after Cd exposure: subacute and subchronic effects, respectively): one group received water and two groups received CdCl2 (1.2 mg/kg i.p. and 24 mg/kg oral). The testicular concentration of essential minerals and Cd, activity of antioxidant enzymes and markers of oxidative stress, histology, and testicular histomorphometry were evaluated. The subacute effect of oral Cd showed reduced Fe concentration, while Ca and Cu increased in this route. The subchronic effect promoted decreasing in Mg in i.p. and oral routes, whereas Zn decreased only in the oral, and the Fe concentration did not change. SOD activity decreased in the oral subacute evaluation and in both pathways, i.p. and oral routes, in the subchronic evaluation, while GST activity increased, and MDA concentration decreased. Labeling of apoptotic cells was increased in the subacute and subchronic evaluation. Seminiferous epithelium degeneration, death of germ cells, and Leydig cell damages occurred in i.p. and oral routes. However, these damages were more intense in the oral route, mainly evaluating the subchronic effects. The results confirm that the severity of Cd-induced testicular injury depends on the pathway, as well as the duration of exposure.

Study on evaluation of toxicology and quality control of Yimusake tablet.

ETHNOPHARMACOLOGICAL RELEVANCE: The Yimusake tablet (YMSK-T) is a type of Xinjiang Uygur Medicine, which affects curing diseases of impotence and premature ejaculation. It has remarkable pharmacological effects that mainly involve improving the number and shape of smooth muscle cells in the corpus cavernosum and enhancing the relaxation and contraction function of corpus cavernosum smooth muscle. AIM OF THE STUDY: The YMSK-T prescription, which consists of 11 traditional herbs, has significant pharmacological effects, however the evaluation of toxicology and quality control of the preparation has not yet been reported. Therefore, in this study, we evaluated the toxicology and quality control of YMSK-T to ensure its safety and effectiveness in clinical applications. MATERIALS AND METHODS: Male rats were divided into three groups and were given continuous gavage administration of high, medium and low concentrations of YMSK-T. To determine hematopoietic parameters, orbital blood was collected at regular intervals. At termination of the experiment, rats were dissected for histopathological examination. According to the function of the prescription medicinal materials, seven active components were selected for content determination under the same chromatographic condition of using 0.2% aqueous phosphoric acid (solvent A) and acetonitrile (solvent B) with a 40 min post time: 0-13 min, 20% →30% B; 13-26 min, 30% →72% B; 26-38 min, 72% →92% B; 38-40 min, 92% →96% B. The column was maintained at 25 °C and the total sample injection was 10 µL. RESULTS: Our data showed that using a large dose (400X the dosage used in humans) of YMSK-T resulted in myocardium and liver damage, and eventually death of the rats. At sub-chronic toxicity, no significant differences were observed among indexes about relative organ weight, hematology, serum biochemistry and histopathological examination, and rats behaved normally. Our results also demonstrated that the YMSK-T dosage used was not toxic in the normal range. The linearity of each component was sufficient (correlation coefficients>0.9997). Moreover, the relative standard deviations of precision, repeatability, stability, and recovery were less than 2.0%, which showed that the method for determination of content was stable and reliable. CONCLUSIONS: YMSK-T has been found to be relatively safe in a rat model, and the method of content determination can be used for quality control of YMSK-T. Toxicology and quality control studies indicated that, the drug is safe and effective for clinical application.

Evaluation of the exposure, dose-response and fate in the lung and pleura of chrysotile-containing brake dust compared to TiO2, chrysotile, crocidolite or amosite asbestos in a 90-day quantitative inhalation toxicology study - Interim results Part 1: Experimental design, aerosol exposure, lung burdens and BAL.

This 90-day repeated-dose inhalation toxicology study of brake-dust (BD) (brakes manufactured with chrysotile) in rats provides a comprehensive understanding of the biokinetics and potential toxicology in the lung and pleura. Exposure was 6 h/d, 5d/wk., 13wks followed by lifetime observation (~20 % survival). Control groups included a particle control (TiO2), chrysotile, commercial crocidolite and amosite asbestos. Aerosol fiber distributions of the chrysotile, crocidolite and amosite were similar (fibers L > 20 µm/cm3: chrysotile-Low/High 29/72; crocidolite 24; amosite 47 fibers/cm3; WHO-fibers/cm3: chrysotile-Low/High 119/233; crocidolite 181; amosite 281 fibers/cm3). The number of particles/cm3 in the BD was similar to that in the chrysotile, crocidolite & amosite exposures (BD 470-715; chrysotile 495-614; crocidolite 415; amosite 417 particles/cm3). In the BD groups, few fibers L > 20 µm were observed in the lungs at the end of exposure and no fibers L > 20 µm at 90d post exposure. In the chrysotile groups, means of 204,000 and 290,000 fibers(L > 20 µm)/lung were measured at 89d. By 180d, means of 1 and 3.9 fibers were counted on the filter corresponding to 14,000 and 55,000 fibers(L > 20 µm)/lung. In the crocidolite and amosite groups mean lung concentrations were 9,055,000 and 11,645,000 fibers(L > 20 µm)/lung at 89d. At 180d the means remained similar with 8,026,000 and 11,591,000 fibers(L > 20 µm)/lung representing 10-13% of the total lung fibers. BAL determined the total number of macrophages, lymphocytes, neutrophils, eosinophils, epithelial-cells and IL-1 beta, TNF-alpha and TGF-beta. At the moderate aerosol concentrations used in this study, neutrophil counts increased ~5 fold in the amphibole asbestos exposure groups. All other groups and parameters showed no important differences at these exposure concentrations. The exposure and lung burden results provide a sound basis for assessing the potential toxicity of the brake dust in comparison to the TiO2 particle control and the chrysotile, crocidolite and amosite asbestos control groups. The BAL results provide an initial indication of the differential response. Part 2 presents the presentation and discussion of the histopathological and confocal microscopy findings in this study through 90 days post exposure.

Pulmonary toxicity in rats following inhalation exposure to poorly soluble particles: The issue of impaired clearance and the relevance for human health hazard and risk assessment.

Intensive discussions are ongoing about the interpretation of pulmonary effects observed in rats exposed to poorly soluble particles. Alveolar clearance differs between rats and humans and becomes impaired in rats at higher exposure concentrations. Some have doubted the human relevance of toxic effects observed in rats under impaired clearance conditions and have suggested that experimental exposures should stay below concentrations inducing impaired clearance. However, for regulatory purposes, insight in potential health effects at relatively high concentrations is needed to fully understand the hazard. Many aspects of impaired particle clearance remain unclear, hampering human health hazard and risk assessment. For an adequate evaluation of the impact of impaired clearance on pulmonary toxicity, a clear definition of alveolar clearance is needed that enables to quantitatively relate the level of impairment to the induction of adverse pulmonary health effects. Also, information is needed on the mechanism of action and the appropriate dose metric for the pulmonary effects observed. In absence of these data, human hazard and risk assessment can only be performed in a pragmatic way. Unless available data clearly point out otherwise, rat pulmonary toxicity including lung inflammation and tumour formation, needs to be considered relevant for human hazard and risk assessment.

Acute and sub-chronic oral toxicity studies of hesperidin isolated from orange peel extract in Sprague Dawley rats.

Citrus sinensis contains glycoside hesperetin-7-rhamnoglucoside (hesperidin) which harbor an array of therapeutic potentials including antioxidant, anticancer, and anti-inflammatory. However, a systematic examination of safety is needed before its utilization. Hence, the present investigation is aimed to evaluate acute and sub-chronic toxicity of hesperidin isolated from the citrus fruit. Hesperidin (73%) was isolated from a methanolic extract of dried peel of the citrus fruit, characterized using FTIR, and standardized by HPLC. Its acute oral toxicity (AOT) and sub-chronic toxicity studies were carried out in Sprague-Dawley rats. Hesperidin (5000 mg/kg) showed 10% mortality in AOT. In sub-chronic toxicity study, hesperidin (250 and 500 mg/kg) did not induce any abnormalities in body weight, food consumption, clinical signs, ophthalmological and neurological observations, urine analysis, hematology, clinical chemistry, organ weights, and gross pathology. However, hesperidin (1000 mg/kg) showed significant (p < 0.05) alterations in body and organ weights, hematology, clinical chemistry, and tissue histopathology. To conclude, hesperidin has median lethal dose (LD50) of 4837.5 mg/kg, and Low Observed Adverse Effect Level (LOAEL) at 1000 mg/kg for both male and female Sprague-Dawley rats. Thus, hesperidin isolated from citrus fruit showed a good safety profile in animal study.

Interstitial Adipocytes in the Beagle Dog and New Zealand White Rabbit Choroid Plexus.

The choroid plexus (CP) produces cerebrospinal fluid and has epithelial, interstitial, and vascular compartments. The CP is a potential site of toxicity, and recognizing the normal microanatomy in different animal models is important for the pathologist. In preclinical studies with beagle dog and New Zealand white rabbits, we observed variable numbers of adipocytes in the CP interstitium of control and xenobiotic-treated animals. The adipocytes were unilocular and consistent morphologically with white adipose tissue. There was a striking variability in the number of adipocytes; however, the presence of adipocytes was not associated with other microscopic findings that would suggest a pathologic process. The morphology of adipocytes was reminiscent of what is observed normally in the interstitium of other tissues like skeletal muscle, bone marrow, and the subcutis. Therefore, we propose that the interstitial adipocytes not be recorded as a finding in preclinical studies unless the adipocytes are altered spontaneously (ie, lipoma) or after xenobiotic treatment.

Subchronic (90-day) repeated dose toxicity study of 2-hydroxybenzylamine acetate in rats.

2-Hydroxybenzylamine (2-HOBA), a naturally occurring compound found in buckwheat, can protect cells and tissues from oxidative stress. In this study, 2-HOBA acetate was orally administered to male and female rats for 90 consecutive days at doses of 100, 500, and 1000 mg·kg BW-1·d-1 (n = 20 per sex/group). Subchronic administration of 2-HOBA was well tolerated at all dose levels. 2-HOBA-treated male rats were slightly heavier in the last weeks of the study, but this difference was very small (<5%), did not show a dose-response relationship, and was not observed in female rats. Similarly, some statistically significant changes in serum biochemistry and hematology parameters were noted, but these were not considered to be of biological or toxicological significance. Sporadic differences in organ weights were observed between groups, but all were small (<10%) and unlikely to indicate toxicity. The incidence of histopathological lesions was similar between treated and control groups across all organs. Based upon these findings, the no-observed-adverse-effect level was determined to be ≥ 1000 mg·kg BW-1·d-1, which was the highest dose tested. These results further support no toxicity associated with oral consumption of 2-HOBA acetate in rats and the continued development of 2-HOBA as a dietary supplement or functional food.

[Acute oral toxicity and 90 days feeding test of recombinant human lactoferrin].

OBJECTIVE: To study the edible safety of recombinant human lactoferrin( rh LF) expressed from transgenic cow mammary gland bioreactor. METHODS: According to the food additive safety toxicology evaluation procedures and method, acute oral toxicity in rats and 90 day subchronic toxicity test in mice were done to evaluate the edible safety of rh LF. RESULTS: Acute oral toxicity test indicated that rh LF was no toxic effect during the observation period, mouse acute oral LD50 of recombinant human lactoferrin was greater than 20 000 mg/kg. 90 days feeding test indicated that there was no-observedadverse-effect-level after givening 300 times rh LF recommended dose of animals body, toxicological parameters NOAEL was 10. 00 g/( kg·d). CONCLUSION: According to the acute toxic dose graduation standard, rh LF was nonpoisonous. Rh LF was no-observedadverse-effect-level and no subchronic toxicity after givening 300 times rh LF recommended dose of animals body. According to the result, rh LF was no potential food safety risk.