Repeated Toxicity Study Research Articles

Examination of in vitro and in vivo antitumor activity of PARP1 selective inhibitor D0112-005.

e15115 Background: The approved PARP inhibitors have demonstrated efficacy in ovarian, breast, prostate, and pancreatic cancers, particularly in homologous recombination repair (HRR)-deficient tumors, including BRCA mutant tumors. The severe hematological toxicity of first-generation PARPi in combination with chemotherapy is due to the lack of selectivity for PARP2. So, we developed selective PARP1 inhibitor D0112-005 with the aim to improve safety and efficacy. Methods: The selectivity of D0112-005 on PARP1, PARP2 was measured by chemiluminescent assay kit and PARP trap™ assay kit. The anti-proliferative ability of D0112-005 was evaluated by CCK-8 in BRCA mutant cell lines. In vivo anti-tumor effect of D0112-005 was evaluated in MDA-MB-436 BRCA1 mutant xenograft model. The potential for hematologic toxicity was evaluated in rats for 28 days repeat-dose and dogs for 14 days repeat-dose. Results: D0112-005 is a highly potent and selective inhibitor of PARP1 with 2000-fold selectivity for PARP1 over PARP2 and PARP3. D0112-005 trapped PARP1-DNA with an EC50 value of 6.49 nM. In contrast, the EC50 of PARP2-DNA trapping was 430μM. These data demonstrate that D0112-005 is a potent and selective PARP1 trapper. D0112-005 showed high anti-proliferation activity against BRCA mutant MDA-MB-436 and HCC1395 cell lines, with IC50 values of 2.06 nM and 2.446 nM, respectively. In the MDA-MB-436 BRCA1m xenograft model, a dose-dependent anti-tumor effect was observed after 21 days administration, with TGIs of 38.77%, 106.7% and 111.73% at the dose of 0.1, 0.3 or 1 mg/kg once daily by oral, respectively. In the 1 mg/kg group, the anti-tumor efficacy was maintained after 14 days of drug withdrawal. D0112-005 showed well tolerance without bodyweight loss. In rat 28 days repeat dose study, D0112-005 100mg/kg had less changes on hematologic parameters compared with Olaparib. The main toxic reaction of D0112-005 (10mg/kg) was reversible thrombocytopenia in dog 14 days repeated toxicity study. Conclusions: D0112-005 potently and selectively inhibits PARP1 resulting in excellent anti-tumor activity in vivo and in vitro, which also good safety profile in the repeated toxicity study in rats and dogs.

TOXICOLOGICAL EVALUATION OF OLEANOLIC ACID (PENTACYCLIC TRITERPENOID) EXTRACTED FROM LANTANA CAMARA ROOTS FOLLOWING ORAL EXPOSURE IN WISTAR RATS

Objective: The aim of the present study was to perform an acute toxicity study to obtain information on the possible adverse effects from a single oral administration of Oleanolic acid in Wistar rats as the onset of toxicity, and to determine the range of exposure (to the LD50 cut-off criteria). Following a sub-chronic 90-days Repeated toxicity study by oral route to determine any potential indication of its dose response relationship and determine no observed effect level (NOEL)/ no-observed adverse effect level (NOAEL)/ low observed effect level (LOEL)/ low observed adverse effect level (LOAEL). Methods: A dose level of 2000mg/kg body weight was employed as step one for single acute study. Based on the survival pattern of the previously dosed animals after 48 hours, same dose 2000 mg/kg body weight) was repeated for Step 2 as a confirmatory test. For the 90-day toxicity study, the highest dose was determined as 1000mg/kg Body weight, and the middle and lower doses were 500 and 250mg/kg Body weight respectively. The rat group was held for a 14-day recovery period after the last dose administration, to observe for any persistence or reversal of toxic effects. Results: Results of the acute toxicity study showed no mortality on the dose level of 2000mg/kg body weight with no significant clinical and body weight changes. During the 90-day Repeated dose oral sub-chronic toxicity study, no rats died. There were no significant clinical changes related to the test item in terms of functional evaluation, body weight, food and water consumption, ophthalmological tests, urine analysis, necropsy findings, or organ weight, Hematology, and biochemistry at the highest dose level of 1000 mg/kg bwt. Conclusion: It is concluded that LD50 Cut-off Value of “Oleanolic acid” in from acute oral toxicity study in Wistar Rats is 2000 mg/kg b.wt. In addition, 90 days study have showed no significant changes with respect to any hematological or blood chemical analyses in 1000, 500 and 250 mg/kg bwt groups. Based on histopathological findings, clinical signs and other parameters, it may be concluded that upon repeated once oral administration for consecutive 90 days, the Oleanolic acid (Pentacyclic Triterpenoid) extracted from Lantana camara roots at the dose level of 1000 mg/kg body weight have caused no adverse effect in both sexes of Wistar Rats.

Cross-protective efficacy and safety of an adenovirus-based universal influenza vaccine expressing nucleoprotein, hemagglutinin, and the ectodomain of matrix protein 2

It is necessary to develop universal vaccines that act broadly and continuously to combat regular seasonal epidemics of influenza and rare pandemics. The aim of this study was to find the optimal dose regimen for the efficacy and safety of a mixture of previously developed recombinant adenovirus-based vaccines that expressed influenza nucleoprotein, hemagglutinin, and ectodomain of matrix protein 2 (rAd/NP and rAd/HA-M2e). The vaccine efficacy and safety were measured in the immunized mice with the mixture of rAd/NP and rAd/HA-M2e intranasally or intramuscularly. The minimum dose that would be efficacious in a single intranasal administration of the vaccine mixture and cross-protective efficacy against various influenza strains were examined. In addition, the immune responses that may affect the cross-protective efficacy were measured. We found that intranasal administration is an optimal route for 107 pfu of vaccine mixture, which is effective against pre-existing immunity against adenovirus. In a study to find the minimum dose with vaccine efficacy, the 106 pfu of vaccine mixture showed higher antibody titers to the nucleoprotein than did the same dose of rAd/NP alone in the serum of immunized mice. The 106 pfu of vaccine mixture overcame the morbidity and mortality of mice against the lethal dose of pH1N1, H3N2, and H5N1 influenza infections. No noticeable side effects were observed in single and repeated toxicity studies. We found that the mucosal administration of adenovirus-based universal influenza vaccine has both efficacy and safety, and can provide cross-protection against various influenza infections even at doses lower than those previously known to be effective.

Pirarubicin loaded biodegradable nanoparticles downregulate IL-6, COX-II and TNF-α along with oxidative stress markers in comparison to conventional pirarubicin in healthy albino rats

Pirarubicin (PRB) is an anthracycline antibiotic that has shown equal or superior cytotoxicity compared to doxorubicin. However, the detailed toxicological profile for Pirarubicin has not yet been investigated. The present study was designed to access the acute and chronic toxicity of the nanoformulation coupled with inflammatory and oxidative stress responses. PRB was encapsulated in PLGA nanoparticles and was physico-chemically evaluated. The nanoparticle size was found to be 420.0 ± 8.2 nm with an encapsulation efficiency of 80.3 ± 3.1%. The SEM images showed spherical nanoparticles while the drug release in PBS (pH 7.4) was estimated to be 72.5 ± 3.5%. Acute toxicity in female albino rats was conducted for 14 days at two dosage levels (i.e., 5 and 300 mg/kg) once a week through an intravenous route. A repeated toxicity study was conducted for 28 days at 3 different dosage levels (i.e., 30, 60 and 100 mg/kg) weekly. No mortality was observed during the experimentation period. Toxicity assessment of body weights, hematological parameters, blood biochemistry, histopathological evaluation of internal organs and relative organ weight percentage was done. Inflammatory markers quantification (COX-II, TNF-α, IL-6) along with the generation of oxidative stress (SOD, GSH-ST, GSH-PX, MDA, and H2O2) was also investigated in a repeated 28 days toxicity study. The nanoformulation did not have any effect on the behavioral pattern, food, water consumption or body weights. The abnormalities in function and morphology of the organs produced by nano-formulated PRB were dose-dependent and reversible. The serum sample of rats treated with nanoparticles exhibited a non-significant difference in levels of COX-II, TNF-α, and IL-6 as compared to the normal saline (NS) group. Altogether the results offered us evidence about the safety profile of Pirarubicin loaded PLGA nanoparticles (PRB-NP) as compared to PRB alone.

Safety Evaluation of Curcumol by a Repeated Dose 28-Day Oral Exposure Toxicity Study in Rats

Curcumol, a natural product isolated from the traditional Chinese medicine Rhizoma curcumae, possesses various potential therapeutic values in many diseases. However, evidence of its toxicological profile is currently lacking. In this study, a repeated toxicity study of curcumol was conducted for the first time. SD rats were exposed to doses of 250, 500, 1000 mg/kg in a selected dose formulation for 28 days through oral administration. The potential toxic effects of curcumol on the blood system were observed and further validated in vivo and in vitro. Moreover, other hematology and biochemistry parameters as well as the weight of organs were altered, but no related histopathological signs were observed, indicating these changes were not regarded as toxicologically relevant. Our current findings provide a complete understanding of the safety profile of curcumol, which may contribute to its further study of investigational new drug application.

Efficacy and safety evaluation of black ginseng (Panax ginseng C.A. Mey.) extract (CJ EnerG): broad spectrum cytotoxic activity in human cancer cell lines and 28-day repeated oral toxicity study in Sprague-Dawley rats

BackgroundGinseng (Panax ginseng C.A. Mey.) has been used as a valuable ingredient in traditional medicine for thousands of years mostly in Asian countries due to its therapeutic effects in various diseases. Among the processed ginseng products, black ginseng is produced by a repeated steaming and drying process of ginseng roots and has been known for its superior efficacy based on high accumulation of minor ginsenosides as recently discovered. Despite its popularity and increasing use, the toxicity information on black ginseng still remained largely lacking, raising safety concerns. This study was therefore carried out to determine the repeated oral toxicity of black ginseng extract (BGE; CJ EnerG) with evaluation of cytotoxic activity as validation of its pharmacological activity for toxicity testing.MethodsPrior to the toxicity test, we examined the cytotoxicity of BGE in six cancer cell lines derived from distinct human tissues in comparison with red ginseng extract (RGE), ginsenosides Rg5 and 20(S)-Rg3, and then assessed 28-day repeated oral toxicity in Sprague-Dawley (SD) rats using daily administration of up to 2000 mg/kg BGE.ResultsBGE showed higher cytotoxicity than RGE in all the cell lines used in this study. Interestingly, the efficacy of BGE closely resembled the cytotoxic pattern of Rg5, suggesting Rg5 as the main effector in the cytotoxic activity of BGE. During the toxicity study, BGE-treated groups showed no noticeable abnormality in clinical signs, body weight gain, food and water consumption and urinalysis. Furthermore, hematological, serum biochemical and histopathological analyses did not find any BGE-related toxicity.ConclusionOur findings demonstrated that BGE has broad-spectrum in vitro cytotoxic activity, and that NOAEL of BGE in SD rats is > 2000 mg/kg, providing the essential safety information for human consumption.

Toxicity profiling of the ethanolic extract of Citrullus lanatus seed in rats: behavioral, biochemical and histopathological aspects.

Citrullus lanatus (Cucurbitaceae) is conventionally used for the treatment of urinary tract infection, renal stones, hypertension, diabetes and diarrhoea. Current study evaluates acute and 28 days repeated toxicity ethanolic extract of C. lanatus seed (EECLS) in Wistar rats to measure its safety profile. The single dose (2000 mg/kg BW) of EECLS was administered while in 28 days repeated study 250, 500 and 1000 mg/kg BW were administered orally in rats. Parameters such as biochemical, haematological and histopathological were analysed in subacute toxicity study. During study, no apparent sign of toxicity, behavioural changes and mortality were detected in acutely exposed animals. In 28 days repeated toxicity study, rats did not show significant changes in behaviour, gross pathology, body weight, biochemical and haematological parameters. Abridged serum glucose and cholesterol levels during the study designate their roles in treatment of hyperglycaemic and hyperlipidaemic conditions. No significant difference was observed in histopathology of liver and kidneys of treated rats. The current investigation demonstrated that EECLS is non-toxic below 1000 mg/kg BW and provides protection to some body organs. The data propose that LD50 of EECLS was greater than 2000 mg/kg BW and the no observed adverse effect level (NOAEL) of EECLS was at the dose of 1000 mg/kg in rats. Taken together, our finding suggests that, EECLS is safe and provides some protection to body organs; also, its extract can be used for further preclinical and clinical evaluation for its therapeutic activity.

28 Days repeated oral toxicity study of Rosmarinus officinalis in Wistar Rats

Rosmarinus officinalis has long been used as a traditional oriental medicine. It is traditionally used as antioxidants as well as essential oil. Rosmarinus officinalis mainly contains the phenolic compounds which is responsible for the antioxidant property. In the present study, 28-day subacute oral dose toxicity studies of hydroalcoholic extracts of the plant of Rosmarinus officinalis were performed in Wistar rats. The repeated oral toxicity study was carried out to detect the no-observed adverse effect level (NOAEL). In this study, a total of 48 rats were classified into the control, low dose (300 mg/kg), medium dose (500 mg/kg) and high dose (1000 mg/kg) treatment groups. The extract was administered daily from day 1 until day 28. At the end of the study, the animals were humanely sacrificed and assessed for the effect extract of Rosmarinus officinalis plant on body weight and relative organ weights, biochemical, haematological and histopathological parameters. The biochemical parameters for the assessment of kidney and liver injuries were carried out. Results of haematological and biochemistry results showed no changes in the control and treated groups. In the histopathology, evaluation of kidney tissues in all treated groups showed no significant (p > 0.05) lesions. The results conclude that hydro-alcoholic extract of leaves Rosmarinus officinalis was found to be safe at highest dose level of 1000mg/kg for 28 days of oral administration.
 Keywords: Repeated toxicity study, Rosmarinus officinalis, biochemical analysis, histopathological study

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

BackgroundCitrus 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.MethodsWe 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.ResultsSingle 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.ConclusionFCPE 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.

Acute and Sub-Acute Toxicity Assessment of the Hydroalcoholic Extract of Madhuca Longifolia Leaves in Wistar Rats

ABSTRACTThe in vivo acute and sub-acute toxicity of the hydroalcoholic leaf extract of Madhuca longifolia (HAEML) were evaluated as per the OECD guidelines. In the acute toxicity study, Albino Wistar rats were administered orally with 2000 mg kg−1 b.w. of HAEML and the animal behavior, adverse effect and mortality were observed for 14 d. Sub- acute toxicity study was conducted by oral administration of the extracts at daily doses of 200 and 400 mg kg−1 b.w. for 28 d. At the end of the treatment period the rats were sacrificed for hematological, biochemical and histopathological studies. No toxic signs or mortality were observed during the experimental period. Hence, the LD50 of the HAEML extracts was determined to be greater than 2000 mg kg−1 b.w. In repeated dose sub-acute toxicity study, the results did not reveal any treatment-related abnormalities in terms of body weight, relative organ weight and biochemical parameters. However, there was a notable difference in hematological profile and antioxidant enzymes. No gross morphological alteration was observed in histopathological studies.

Safety Assessment of Mentha mozaffarianii Essential Oil: Acute and Repeated Toxicity Studies.

Mentha mozaffarianii, an endemic species from the Labiatae family, is used in Iranian traditional medicine. This study evaluated the acute and repeated oral toxicity of the Mentha mozaffarianii essential oil (MMEO) in rats and mice. To assess the toxicity profile of the MMEO, we administered the essential oil to 48 rats and mice of both sexes by gavage in acute and repeated models. In acute toxicity, the animals were administered the MMEO (2000 mg/kg) and were monitored for 14 days. In the repeated toxicity, the MMEO was administered (100 mg/kg) daily for 4 weeks. On the 28th day, all the animals were scarified and blood and tissue samples were prepared. All the clinical, biochemical, and histopathological changes were assessed and compared with those in the controls. Statistical significance was determined by one- and two-way analyses of variance, followed by the Tukey test using GraphPad Prism 6. In the acute test, there was no mortality; therefore, the oral LD50 value determined in the mice and rats of both sexes was greater than 2000 mg/kg. In the repeated test, the animals received the MMEO and there was no mortality. In the biochemical analysis, there were significant increases in blood glucose, cholesterol, ALT, AST, ALP, and TSH in the female rats and also in BUN in the male rats. The histopathological studies revealed evidence of microscopic lesions in the liver, kidney, stomach, and small intestine tissues of the MMEO group. The results indicated that the acute toxicity of the MMEO in the mice and rats was of a low order and it revealed slight tissue damage to several organs when given subchronically at a dose of 100 mg/kg.

Thyrotoxic rubber antioxidants, 2-mercaptobenzimidazole and its methyl derivatives, cause both inhibition and induction of drug-metabolizing activity in rat liver microsomes after repeated oral administration

We examined the effects of thyrotoxic rubber antioxidants, 2-mercaptobenzimidazole (MBI, 0.3 mmol/kg/day) and its methyl derivatives, methyl-MBIs [4-methyl-MBI (4-MeMBI, 0.6 mmol/kg/day), 5-methyl-MBI (5-MeMBI, 0.6 mmol/kg/day), and 4(or 5)-methyl-MBI (4(5)-MeMBI, 0.6 or 1.2 mmol/kg/day)], on the drug-metabolizing activity in male rat liver microsomes by 8-day repeated oral administration. The weight of liver and thyroid were increased by all the test chemicals; MBI was most potent, and there was no additive or synergistic effect between 4-MeMBI and 5-MeMBI. MBI decreased the cytochrome P450 (CYP) content, NADPH-cytochrome P450 reductase (POR) activity, 7-ethoxycoumarin O-deethylation (ECOD) activity, and flavin-containing monooxygenase (FMO) activity, but increased the 7-pentoxyresorufin O-depentylation (PROD) activity, suggesting inhibition of the drug-metabolizing activity on the whole but induce some activities such as the CYP2B activity. On the contrary, all the methyl-MBIs increased the CYP content, CYB5 content, ECOD activity, 7-ethoxyresorufin O-deethylation (EROD) activity, and PROD activity, indicating that they are mostly inducible of the CYP activity. However, the methyl-MBIs decreased the FMO activity, and 5-MeMBI and 4(5)-MeMBI appeared inhibitory for CYPs 2C11 and 2C13. Between 4-MeMBI and 5-MeMBI, there was no additive or synergistic effect on the drug-metabolizing activity, but was counteraction. It was concluded that MBI and methyl-MBIs had both inhibitory and inducible effects on the drug-metabolizing activity in rat liver microsomes at thyrotoxic doses. The effects of 4(5)-MeMBI indicated that the increased liver weight alone can be a hepatotoxic sign but not an adaptive no-adverse response in toxicity studies. The present results were related to the toxicokinetic profiles of MBI and 4(5)-MeMBI in the repeated toxicity studies.

Discovery of hepatitis B virus capsid assembly inhibitors leading to a heteroaryldihydropyrimidine based clinical candidate (GLS4)

Inhibition of hepatitis B virus (HBV) capsid assembly is a novel strategy for the development of chronic hepatitis B (CHB) therapeutics. Herein we described our lead optimization studies including the synthesis, molecular docking studies and structure-activity relationship (SAR) studies of a series of novel heteroaryldihydropyrimidine (HAP) inhibitors of HBV capsid assembly inhibitors, and the discovery of a potent inhibitor of HBV capsid assembly of GLS4 (ethyl 4-[2-bromo-4-fluorophenyl]-6-[morpholino-methyl]-2-[2-thiazolyl]-1,4-dihydro-pyrimidine-5-carboxylate) which is now in clinical phase 2. GLS4 demonstrated potent inhibitory activities in HBV HepG2.2.15 cell assay with an EC50 value of 1nM, and it also exhibited high potency against various drug-resistant HBV viral strains with EC50 values in the range of 10–20nM, more potent than the typical HBV polymerase inhibitors such as lamivudine, telbivudine, and entecavir. Pharmacokinetic profiles of GLS4 were favorable and safety evaluation including acute toxicity and repeated toxicity study indicated that GLS4 was safe enough to support clinical experiments in human.

Comparative subcutaneous repeated toxicity study of enoxaparin products in rats

Enoxaparin is a low-molecular-weight heparin widely used for the prevention and treatment of thromboembolism. With the development of several enoxaparin biosimilars, real medical concerns about their safety and efficacy have been raised. This repeated dose toxicity study consists of preclinical toxicological evaluation of a biosimilar biological version of enoxaparin, the drug product “Enoxa”, compared to the enoxaparin reference drug product, “Lovenox”. Eighty white Wistar rats were treated with “Enoxa” versus the reference product, using subcutaneous therapeutic and toxic doses, varying from 3.5 to 100 mg/kg/day. Dose levels were adjusted and ultimately fixed at 3.5 and 20 mg/kg/day as therapeutic and toxic doses, respectively. A sodium chloride solution (0.9%) was used as the control, and the comparative study was conducted over periods of 14 and 28 days. Comparable effects were observed with few adverse effects at the administration dose of 20 mg/kg/day, for both enoxaparin biosimilar and reference products. Interestingly, mortality started only at high doses of 40 mg/kg/day and reached 25% at 100 mg/kg/day for both products. These results, as part of the recommended biosimilarity monitoring, demonstrated comparable toxicity profiles of “Enoxa” and “Lovenox” products in rats. Continuing investigation of biosimilarity on humans to confirm safety and efficacy is suggested.

The Safety Evaluation of Salvianolic Acid B and Ginsenoside Rg1 Combination on Mice.

Our previous study indicated that the combination of salvianolic acid B (SalB) and ginsenoside Rg1 (Rg1), the main components of Salvia miltiorrhizae and Panax notoginseng, improves myocardium structure and ventricular function in rats with ischemia/reperfusion injury. The present study aimed to determine the safety of the combined SalB and Rg1 (SalB-Rg1) in mice. The safety of SalB-Rg1 was evaluated through acute toxicity and repeated-dose toxicity. In the acute toxicity study, the up and down procedure was carried out firstly, and then, the Bliss method was applied. In the toxicity study for seven-day repeated treatment of SalB-Rg1, forty Kunming mice were randomly divided into four groups. The intravenous median lethal dose (LD50) of the SalB-Rg1 combination was 1747 mg/kg using the Bliss method. For both the acute toxicity study and the seven-day repeated toxicity study, SalB-Rg1 did not induce significant abnormality on brain, heart, kidney, liver and lung structure at any dose based on H&E stain. There were no significant changes related to the SalB-Rg1 toxicity detected on biochemical parameters for two kinds of toxicity studies. The LD50 in mice was 1747 mg/kg, which was more than one hundred times higher than the effective dose. Both studies of acute toxicity and seven-day repeated dose toxicity indicated the safety of the SalB-Rg1 combination.

Essential oil of Syzygium aromaticum reverses the deficits of stress-induced behaviors and hippocampal p-ERK/p-CREB/brain-derived neurotrophic factor expression.

Syzygium aromaticum has been widely used in traditional medicine. Our study investigated the safety and antidepressant-like effects of the essential oil of S. aromaticum after acute or long-term treatment. Using GC-MS, a total of eight volatile constituents were identified in the essential oil of S. aromaticum. The single LD50 was approximately 4500 mg/kg based on a 24-h acute oral toxicity study. In a long-term repeated toxicity study of this essential oil (100, 200, and 400 mg/kg, p. o.), only 400 mg/kg induced a significant decrease in body weight. In addition, no significant changes in relative organ weights and histopathological analysis were observed in all doses of essential oil-treated mice compared with the control group. Furthermore, acute S. aromaticum essential oil administration by gavage exerted antidepressant-like effects in the forced swimming test (200 mg/kg, p < 0.05) and tail suspension test (100 and 200 mg/kg, p < 0.05). Long-term S. aromaticum essential oil treatment via gavage significantly increased sucrose preference (50 mg/kg, p < 0.05; 100 and 200 mg/kg, p < 0.01) as well as elevated the protein levels of hippocampal p-ERK, p-CREB, and brain-derived neurotrophic factor in mice exposed to chronic unpredictable mild stress. These results confirmed the safety of the essential oil of S. aromaticum and suggested that its potent antidepressant-like property might be attributed to the improvement in the hippocampal pERK1/2-pCREB-BDNF pathway in rats exposed to chronic unpredictable mild stress.

Toxicological evaluation of lactase derived from recombinant Pichia pastoris.

A recombinant lactase was expressed in Pichia pastoris, resulting in enzymatic activity of 3600 U/mL in a 5 L fermenter. The lactase product was subjected to a series of toxicological tests to determine its safety for use as an enzyme preparation in the dairy industry. This recombinant lactase had the highest activity of all recombinant strains reported thus far. Acute oral toxicity, mutagenicity, genotoxic, and subchronic toxicity tests performed in rats and mice showed no death in any groups. The lethal dose 50% (LD50) based on the acute oral toxicity study is greater than 30 mL/kg body weight, which is in accordance with the 1500 L milk consumption of a 50 kg human daily. The lactase showed no mutagenic activity in the Ames test or a mouse sperm abnormality test at levels of up to 5 mg/plate and 1250 mg/kg body weight, respectively. It also showed no genetic toxicology in a bone marrow cell micronucleus test at levels of up to 1250 mg/kg body weight. A 90-day subchronic repeated toxicity study via the diet with lactase levels up to 1646 mg/kg (1000-fold greater than the mean human exposure) did not show any treatment-related significant toxicological effects on body weight, food consumption, organ weights, hematological and clinical chemistry, or histopathology compared to the control groups. This toxicological evaluation system is comprehensive and can be used in the safety evaluation of other enzyme preparations. The lactase showed no acute, mutagenic, genetic, or subchronic toxicity under our evaluation system.

Effects of the Methanol Root Extract of Cissampelos mucronata A. Rich on the Kidney and Liver of Rats- a Histological and Biochemical Study

Aim: The aim of this study was to determine the potential toxicologic effects of the methanol root extract of Cissampelos mucronata (A. Rich) on liver and kidney tissues. Methodology: A total of 30 rats were used for the study consisting of 5 female rats for the acute toxicity study and 25 rats for the 28 day repeated toxicity studies, the 25 rats were divided into five groups of 5 rats per group. Group I served as the control, while r ats

Evaluation of General Toxicity and Genotoxicity of the Silkworm Extract Powder

The silkworm extract powder contain 1-deoxynojirimycin (DNJ), a potent α-glycosidase inhibitor, has therapeutic potency against diabetes mellitus. Therefore, natural products containing DNJ from mulberry leaves and silkworm are consumed as health functional food. The present study was performed to evaluate the safety of the silkworm extract powder, a health food which containing the DNJ. The repeated toxicity studies and gentic toxicity studies of the silkworm extract powder were performed to obtain the data for new functional food approval in MFDS. The safety was evaluated by a single-dose oral toxicity study and a 90 day repeated-dose oral toxicity study in Sprague-Dawley rats. The silkworm extract powder was also evaluated for its mutagenic potential in a battery of genetic toxicity test: in vitro bacterial reverse mutation assay, in vitro chromosomal aberration test, and in vivo mouse bone marrow micronucleus assay. The results of the genetic toxicology assays were negative in all of the assays. The approximate lethal dose in single oral dose toxicity study was considered to be higher than 5000 mg/kg in rats. In the 90 day study, the dose levels were wet at 0, 500, 1000, 2000 mg/kg/day, and 10 animals/sex/dose were treated with oral gavage. The parameters that were monitored were clinical signs, body weights, food and water consumptions, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weights, and histopathological examination. No adverse effects were observed after the 90 day administration of the silkworm extract powder. The No-Observed-Adverse-Effect-Level (NOAEL) of silkworm extract powder in the 90 day study was 2000 mg/kg/day in both sexes, and no target organ was identified.

Tumor necrosis therapy antibody interleukin-2 fusion protein elicits prolonged and targeted antitumor effects in vivo

Interleukin-2 (IL-2) is one of the most successful cytokines applied in tumor immunotherapy because of its ability to stimulate potent cellular immune response. The life-threatening toxicity of vascular leak syndrome (VLS) associated with the high-dose IL-2 treatment regimen has limited its use in tumor immunotherapy. To reverse this situation, a tumor-targeted fusion protein, recombinant human TNT-IL2 (rhTNT-IL2), was generated with both the cytokine activity of IL-2 and the tumor-targeting ability of TNT antibody. TNT is a human tumor necrosis therapy monoclonal antibody capable of binding intracellular antigens which are accessible and abundant in necrotic regions of tumors. The immunotherapeutic potential of this fusion protein was tested in murine melanoma and lung cancer models, and tumor-bearing mice showed satisfied tumor regressions after rhTNT-IL2 immunotherapy. Immunohistochemical study showed a distinct penetration of IL-2 in tumors in mice treated with rhTNT-IL2, indicating its evident tumor-targeting activity. Moreover, the rhTNT-IL2 was well tolerated in cynomolgus monkeys in a 12-week long-term repeated toxicity study. These studies indicate that the targeting of IL-2 to necrotic areas of tumors might be a new approach for the immunotherapy of solid tumors.