• Toxicological Research
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• v.25 no.2
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• pp.59-69
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• 2009

Metabolomics which deals with the biological metabolite profile produced in the body and its relation to disease state is a relatively recent research area for drug discovery and biological sciences including toxicology and pharmacology. Metabolomics, based on analytical method and multivariate analysis, has been considered a promising technology because of its advantage over other toxicogenomic and toxicoproteomic approaches. The application of metabolomics includes the development of biomarkers associated with the pathogenesis of various diseases, alternative toxicity tests, high-throughput screening (HTS), and risk assessment, allowing the simultaneous acquisition of multiple biochemical parameters in biological samples. The metabolic profile of urine, in particular, often shows changes in response to exposure to xenobiotics or disease-induced stress, because of the biological system's attempt to maintain homeostasis. In this review, we focus on the most recent advances and applications of metabolomics in toxicological research.

• Toxicological Research
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• v.24 no.3
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• pp.219-225
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• 2008

A screening study of the acute toxicity of organic arsenics such as arsenobetaine and arsenocholine, a product of arsenic methylation metabolite, and inorganic arsenic was carried out to examine hematological and serum biochemical parameters in cynomolgus monkeys(Macaca fascicularis). We found soft and liquid feces, and vomiting in all treated groups with inorganic and organic arsenics. The monkeys in inorganic arsenic-treated group showed a significant increase in vomiting frequency compared with those in three organic arsenics-treated groups. These results suggest that inorganic arsenic might be more toxic than three other organic arsenics tested. The monkeys in inorganic arsenic-treated group showed a decrease in platelet and an increase in monocyte on day 4 and the monkeys in arsenocholine-treated group showed an increase in reticulocyte percentage on day 8. The monkeys in inorganic-treated group also showed decreases in AST and ALT values and the monkeys in arsenobetaine-treated group showed a decrease in AST value and an increase in T-CHO value. However, these hematological and biochemical changes were within the physiological ranges, showing that the single dose of inorganic and organic arsenics did not affect at least hematological and serum biochemical parameters. The present study of toxicity with single dose of arsenics provides valuable indicators for longer term study of toxicity of repeated doses of arsenics in primates.

• Toxicological Research
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• v.24 no.4
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• pp.289-295
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• 2008

Toxicology screening following treatment with astemizole, a histamine receptor antagonist, at oral doses of 0, 10, 30 and 60 mg/kg was carried out in male cynomolgus monkeys (Macaca fascicularis). No dose-related changes in mortality, clinical signs, body weight changes, food consumption, or urine analysis occurred in any animal compared to the vehicle control. However, the high-dose group showed a decrease in BUN and ALP compared to vehicle control group. In addition, the levels of TG, AST, ALP and CK increased. Although astemizole did not produce significant toxicological changes at any dose tested, we predict that it can cause toxicological changes of the liver and heart based on the changes in the serum parameters related to the heart and liver. The Action Potential Duration (APD) was prolonged in the heart of 60 mg/kg treatment group compared to the control group. The APD increase in 60 mg/kg treatment group along the other related changes in toxicological parameters imply that astemizole has major cardiotoxic effects in the cynomolgus monkey. This study is a valuable assessment for predicting the general toxicity and cardiotoxic effects of antihistamine drugs using nonhuman primates.

• Biomolecules & Therapeutics
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• v.15 no.2
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• pp.102-107
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• 2007

Cimetidine, a substrate for P-glycoprotein (P-gp), is a well known drug interacting with a variety of drugs and results in alteration of pharmacokinetic parameters by concomitant administration. The aim of present study was to investigate whether cimetidine affects the transport of various quinolone antibiotics in human colorectal cancer cell line (Caco-2) system which has been typically used to investigate drug transport via P-gp. The apparent permeability coefficients (P$_{app}$) value of 9 quinolone antibiotics in the co-treatment with cimetidine was examined. Apical to basolateral (AP-to-BL) transport of fleroxacin in the co-treatment with cimetidine was increased to 1.5-fold (p<0.01) compared with that of fleroxacin alone, whereas basolateral to apical (BL-to-AP) transport of fleroxacin was decreased to 0.83-fold significantly (p<0.05). Ofloxacin was decreased to 0.8-fold (p<0.01) and 0.72-fold (p<0.01) significantly in AP-to-BL and BL-to-AP direction, respectively by cimetidine cotreatment. The P$_{app}$ values of gatifloxacin, moxifloxacin, ciprofloxacin and rufloxacin also were changed by cimetidine. These results have a potential that cimetidine influences on the pharmacokinetics of quinolone antibiotics. It suggests that careful drug monitoring and dosage adjustment may be necessary during the co-administration of quinolone antibiotics with cimetidine.

• Toxicological Research
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• v.7 no.1
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• pp.51-59
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• 1991

The purpose of the present study was to investigate the effects of non-watering, fasting and non-watering fasting for 16-17 hrs on haematological and biochemical parameters in SD rats. 1. Liver weight was decreased in the order of in the fasting group, non-watering fasting group and non-watering group in both sexes. 2. In fasting group and non-watering fasting group, haematologic parameters of male (HGB and MCH) and femal (MCHC) were trends to decrease compared with normal feeding & watering group. 3. In the differential leucocyte counts, there were no significant differences compared with noraml feeding % watering group.

• Toxicological Research
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• v.7 no.2
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• pp.165-171
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• 1991

Effects of forced physical exercise on the CCl4 hepatotoxicity were examined in adult female rats. Rats were treated with CCl4 (2 mmol/kg, ip) and introduced into a cylindrical cage rotating at 9 rpm for 20 min/hr for 6 hr. Eighteen hr following the termination of exercise serum sorbitol dehydrogenase (SDH), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) activities and glucose-6-phosphatase activity were determined as parameters for hepatotoxicity. Physical exercise inhibited the $CCI_{4-}$induced increases in SDH, GOT, GPT activity, and glucose-6-phosphatase activity were determined as parameters for hepatotoxicity.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.299-304
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• 2009

Rosiglitazone maleate (RGM) is widely used for improving insulin resistance. RGM is a moderate inhibitor of cytochrome P450 2C8 (CYP2C8) and is also mainly metabolized by CYP2C8. The aim of this study was to determine whether the effect of RGM on CYP2C8 is altered by co-treatment with other drugs, and whether amlodipine camsylate (AC) changes the pharmacokinetics (PK) of RGM. Of the 11 drugs that are likely to be co-administered with RGM in diabetic patients, seven drugs lowered the $IC_{50}$ value of RGM on CYP2C8 by more than 80%. In vitro CYP2C8 inhibitory assays of RGM in combination with drugs of interest showed that the $IC_{50}$ of RGM was decreased by 98.9% by AC. In a pharmacokinetic study, Sprague-Dawley (SD) rats were orally administered 1 mg/kg of RGM following by single or 10-consecutive daily administrations of 1.5 mg/kg/day of AC. No significant changes in the pharmacokinetic parameters of RGM were observed after a single administration of AC, but the AUC and $C_{max}$ values of RGM were significantly reduced by 36% and 31%, respectively, by multiple administrations of AC. In conclusion, RGM was found to be affected by AC by in vitro CYP2C8 inhibition testing, and multiple dosing of AC appreciably changed the pharmacokinetics of RGM. These findings suggest that a drug interaction exists between AC and RGM.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.388-394
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• 2010

Metabolomics aims at the comprehensive, qualitative and quantitative analysis of wide arrays of endogenous metabolites in biological samples. It has shown particular promise in the area of toxicology and drug development, functional genomics, system biology and clinical diagnosis. In this study, analytical technique of MS instrument with high resolution mass measurement, such as time-of-flight (TOF) was validated for the purpose of investigation of amino acids, sugars and fatty acids. Rat urine and serum samples were extracted by selected each solvent (50% acetonitrile, 100% acetonitrile, acetone, methanol, water, ether) extraction method. We determined the optimized liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) system and selected appropriated columns, mobile phases, fragment energy and collision energy, which could search 17 metabolites. The spectral data collected from LC/TOFMS were tested by ANOVA. Obtained with the use of LC/TOFMS technique, our results indicated that (1) MS and MS/MS parameters were optimized and most abundant product ion of each metabolite were selected to be monitorized; (2) with design of experiment analysis, methanol yielded the optimal extraction efficiency. Therefore, the results of this study are expected to be useful in the endogenous metabolite fields according to validated SOP for endogenous amino acids, sugars and fatty acids.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.104-113
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• 2011

We investigated the systemic effects of leaf folder (Cnaphalocrocis medinalis) resistant rice (transgenic rice, Nakdongbyeb) in Sprague-Dawley rats for 13 weeks. Leaf folder resistant rice was added to the diet at percentage levels of 0, 5 and 20 percentage/feeder and was administered for 13 weeks. The results did not show any changes in food and water intake. There were also no biologically significant changes in both body and organ weights, hematological and blood biochemical parameters, autopsy and histopathology between the treatment and control groups. Based on these results, no observed adverse effect level (NOAEL) of transgenic rice was considered to be more than 10,000 mg/kg b.w. under the conditions of the present study.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.239-254
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• 2004

It has been debating about conducting and interpretating of 2-year rodent carcinogenicity bioassay. Although some criticisms arising in usefulness, it has been still known that long-term carcinogenicity studies using rodents would be the only assay system to predict any possible human risks, which would not be replaced. Both regulatory agencies and academies have developed some assay models, however, there have been controversy whether those study designs and interpretations are based on sound scientific rationale and validated data. Such kinds of issues including choice of species/strain, dose level selection, duration of study, number of animals per group, historical control data, monitoring parameters, terminal investigations, peer review, statistics, alternative assay models, interpretation of neoplastic lesions, and risk assessments, were reviewed.