Role of Nrf2 pathway in flutamide-induced mitochondrial biogenesis / 中国临床药理学与治疗学

AIM: To investigate the effect of flutamide on mitochondrial biogenesis and the regulating effect of anoxidative pathway Nrf2 on it. METHODS: Human hepatocyte HepG2 cells were treated with flutamide (0-50 μmol/L) for 24 h, then mtDNA copy number and protein expression of mitochondrial biogenesis were detected by RT-PCR and WB. The effects of ERK1/2 and the role of Nrf2 pathway in mitochondrial biogenesis were further observed by gene knockdown and protein activation/inhibition methods. RESULTS: Flutamide interfered mitochondrial biogenesis concentration-dependently, the mtDNA copy number, ERK1/2 and PGC-1α proteins increased with the dose. ERK1/2 inhibition and activation regulated flutamide-induced mtDNA copy number and PGC-1α expression, and inhibition of Nrf2 pathway also affected flutamide-induced mtDNA copy number and expression of PGC-1α, as well as ERK1/2 expression. CONCLUSION: Flutamide affects mitochondrial biogenesis, and the antioxidant pathway Nrf2 may be involved in the regulation of flutamine-induced mitochondrial biogenesis by regulating ERK1/2.

LC-MS/MS method developed for determination of albiflorin in rat plasma and its application on toxicokinetic study / 国际药学研究杂志

Objective To develop and validate a LC-MS/MS method for the determination of albiflorin in rat plasma. Meth?ods Plasma samples were extracted by liquid-liquid extraction with a mixture of ethyl acetate-isopropanol(95:5,V/V)to prepare samples for analysis. Chromatographic separation was performed on a Poroshell 120 EC-C18 column(50 mm × 2.1 mm I.D. 2.7μm). The mobile phase consisted of acetonitrile-water followed gradient elution. Detection of albiflorin and the internal standard(IS)lacos?amide was achieved by ESI MS/MS in the positive ion mode using m/z 498.5→m/z 197.1 and m/z 251.3→m/z 108.2 transitions,respec?tively. Results The method was linear in the range of 20 to 2000 ng/ml when 50μl plasma was analyzed. The lower limit of quantifi?cation was 20 ng/ml. The inter-and intra-day precision values were both below 15%,and the accuracy(relative error)was within ± 8.06%in all quality control samples. Conclusion The method provides a sensitive and rapid means for the determination of albiflorin in rat plasma,and completely meets the requirements for toxicokinetic study.

Sub-chronic toxicity of MNT-016 by benchmark dose method in Sprague-Dawley rats / 军事医学

Objective To evaluate the repeated dose toxicity of MNT-016 in SD rats and to provide reference for toxicity evaluation.Methods MNT-016 was administered to rats at 5, 20 and 80 mg/kg for 90 days.The toxic effects on the animals were evaluated by observing the clinical signs and measuring the body weight, hematology and blood biochemistry as well as histopathological examination.NOAEL and benchmark dose lower confidence limit(BMDL) were observed by the end point of toxicity.Results Compared with the control group, the AST, TBIL, DBIL and Crea of male rats were increased in a dose-dependent manner, while TG and CHOL decreased.The body mass(before anatomy), heart, liver, thymus, epididymis of male rats in 80 mg/kg group were significantly decreased (P<0.05), while absolute organ mass of the heart and lung was increased.The body mass (before anatomy) and thymus of female rats in 80 mg/kg group were significantly decreased (P<0.05), while absolute organ mass of lungs was increased.Vacuolation of hepatocytes was observed in groups each dose, tubule atrophy was found in the kidneys of 20 and 5 mg/kg groups, and tubule basophilia was observed in 80 mg/kg group.The incidence of the above lesions was higher in male animals than in female ones.Conclusion The NOAEL of MNT-016 is lower than 5 mg/kg in male rats and 5 mg/kg in female rats.BMDL value is 2.65 mg/kg in male animals and more accurate than NOAEL, and is 9.04 mg/kg in female animals,which is slightly larger than the corresponding NOAEL.

Repeated dose toxicity of Tangwang Mingmu granules in Sprague-Dawley rats / 军事医学

Objective To observe toxic symptoms and signs , toxic damage extents and reversibility in rats after oral administration of Tangwang Mingmu granules .Methods Four dose groups with 40 rats in each group were designed in this study, including control group fed with distilled water and three groups at different dosages of the test drug .Tangwang Mingmu granules were orally administered to SD rats at the dosage of 8.4, 4.2 and 2.1 g/kg for 3 weeks and 14.0, 8.4 and 4.2 g/kg for 23 weeks, for 26 consecutive weeks .The general state of the rats was observed every day , while body mass and food consumption were calculated once a week .Halfway through and at the end of the administration (13 and 26 weeks) and after four weeks of recovery, parameters of body mass, hematology, hematological biochemistry, organ/body mass ratio and histopathology were measured .Results Compared with the control group at the same time-point, body mass of male rats in the other three groups was slightly reduced .Food consumption in high and medium dose groups was reduced (P<0.05), MCHC, ALT, TBIL and Na +in high dose group were decreased (P<0.05), TP, ALB and D-BIL were increased (P<0.05), the mean body mass and relative organ weight of thymus in medium dose male rats were decreased (P<0.05), relative organ weight of the liver and kidney in high dose male rats was increased (P<0.05), and focal chronic inflammation to different extent was observed in the liver , kidney and prostate gland .No dose-effect relationship was found in these perturbations that were all within the normal range of animals .No significant drug-related pathological changes were found.Conclusion The NOAEL of Tangwang Mingmu granules is considered to be 14.0 g/kg body mass/day (equal to 50 times the proposed clinical adult dosage ) for the 26-week repeated dose oral toxicity study in male andfemale rats.

Research progress in benchmark dose in risk assessment of long-team exposure toxicity / 军事医学

The purpose of risk assessment is to evaluate the permissible exposure level under specific risk factors.To extrapolate the human acceptable daily intake (ADI) and/or reference dose (RfD), the traditional method uses the no-observed-adverse-effect level ( NOAEL ) to quantify toxicity after being divided by uncertainty factor.There are many limitations with NOAEL method in safety evaluation,for it relies too much on experimental design.Benchmark dose ( BMD) approach is a more reliable method with many advantages.BMD approach and its analysis software, the advantages of BMD over NOAEL, the application and methodological perfection in risk assessment of long-team exposure toxicity are presented in this review.

Development of human embryonic stem cell platforms for human health-safety evaluation / 北京大学学报(医学版)

SUMMARY Thehumanembryonicstemcells(hESCs)serveasaself-renewable,genetically-healthy, pluripotent and single source of all body cells,tissues and organs.Therefore,it is considered as the good standard for all human stem cells by US,Europe and international authorities.In this study,the standard and healthy human mesenchymal progenitors,ligament tissues,cardiomyocytes,keratinocytes,primary neurons,fibroblasts,and salivary serous cells were differentiated from hESCs.The human cellular health-safety of NaF,retinoic acid,5-fluorouracil,dexamethasone,penicillin G,adriamycin,lead ace-tate PbAc,bisphenol A-biglycidyl methacrylate (Bis-GMA)were evaluated selectively on the standar-dized platforms of hESCs,hESCs-derived cardiomyocytes,keratinocytes,primary neurons,and fibro-blasts.The evaluations were compared with those on the currently most adopted cellular platforms.Parti-cularly,the sensitivity difference of PM2.5 toxicity on standardized and healthy hESCs derived fibroblasts, currently adopted immortalized human bronchial epithelial cells Beas-2B and human umbilical vein endo-thelial cells (HUVECs)were evaluated.The results showed that the standardized hESCs cellular plat-forms provided more sensitivity and accuracy for human cellular health-safety evaluation.

Progress in alternative testing strategies for human embryonic stem cell-based drug toxicity / 中国药理学与毒理学杂志

Traditional drug development and pre-clinical tests are based on animals and involve large numbers of animals,costs and long periods. Meanwhile,inter-species differences are difficult to overcome. Human embryonic stem cells (hESCs),which can self-renew and directly differentiate to types of cells,have become a new tool for toxicity alternative testing. hESC-Based alternative testing models,such as the reproductive toxicity test system,neuro development toxicity test system and metabolic model,can be used to predict target organ toxicity and toxic mechanisms of chemicals, analyze metabolic pathways and to search for potential toxicity biomarkers, when combined with omics such techiniques as metabonomics , proteomics and genomics. Therefore, hESC-based alternative testing models have extensive application to toxicology.

Establishment of normal reference ranges for clinical pathology indexes of Beagle dogs in GLP system / 军事医学

Objective To establish the normal reference ranges of clinical pathology for Beagle dogs in the Good Laboratory Practice ( GLP ) system.Method Sixteen biochemical indexes , seventeen hematological indexs and three coagulation function indexes of 117 Beagle dogs were detected , and the mean value of each index and the normal reference ranges were calculated and compared .Results Only alkaline phosphatase ( ALP ) from the biochemical items was significantly different between males and females (P<0.01),which was higher among males than among females .Three in-dexes of hematology were significantly different between males and females (P<0.01),with red blood cell(RBC), hemo-globin(HGB)and hematocrit(HCT)lower among males than among females.The coagulation function items were not signif-icantly different between the two sexes .Conclusion Some indexes of clinical pathology were significantly different between males and females , which should be considered during statistic analysis on toxicity .Our study has established the normal reference range of clinical pathology for Beagle dogs in the GLP system , which provides reference for toxicity tests .

Metabonomics analysis of effects induced by PCBs and high fat diet combined expo-sure in SD rats / 军事医学

Objective To explore the effect on metabolism of glucose and lipids, potential toxicity mechanism and possible biomarker candidates by analyzing urine metabonome changes of rats after oral administration of polychlorinated biphenyl congeners( PCBs) and high fat diet alone or in combination.Methods Male SD rats were divided randomly into control group,high fat diet group, PCBs group and combination group of PCBs and high fat diet.Urine samples were collected after 6-week treatment, 1 H NMR spectra were performed and analyzed by principal component analysis ( PCA) . Results The PCA scores plot of urine 1 H NMR data showed that the combined group could be easily distinguished from the other three groups, suggesting great difference in metabolism.The loading plot of the PCA revealed significant increase in the levels of lactate, glucose, creatine, 2-hydroxy-isovaleric acid and reduction in the levels of citrate, succinate, taurine, hippurate and trimethylamine oxide ( TMAO) in the combined exposure group after six-week exposure.Conclusion The altered levels of metabolites induced by combined exposure of PCBs and high fat diet may be related to the injury to mitochondrial function, reduction of energy metabolism in tricarboxylic acid cycle (TAC).These effects possibly lead to perturbations in the metabolism of glucose, lipid and amino acids.The altered metabolites may be considered biomarker candidates of toxicity induced by exposure to PCBs and high fat diet.

Role of gonadotropin-releasing hormone on advancing rat puberty onset induced by estradiol / 中国药理学与毒理学杂志

OBJECTIVE To investigate the role of gonadotropin-releasing hormone (GnRH) in es-tradiol(E2 ) induced advance of puberty onset in rats. METHODS Postnatal day 18 SD rats were given a daily intragastric administration of corn oil or E2(50 μg.kg-1 ) for consecutive 5 d. The day of vaginal opening (VO), pathological changes in ovary and protein expression levels of GnRH, G protein-coupled receptor 54 ( GPR54) and phospholipase C ( PLC) in hypothalamus were observed. RESULTS As compared to corn oil controll group, VO was advanced by about 12.2 d, corpus luteum was observed in the ovary section, and the protein expression levels of GnRH,GPR54 and PLC in hypothalamus were significantly increased by 47%, 55% and 56% in E2 group, respectively. CONCLUSION E2 induced onset of puberty advance may be closely related to regulation of the expression of GnRH, GPR54 and PLC in hypothalamus.

T-2 toxin inhibits mitochondrial function of differentiated murine embryonic stem cells / 中国药理学与毒理学杂志

OBJECTIVE ToexplorethepossiblemechanismoractiontargetsofT-2toxinembryo toxicity by observing the effect of T-2 toxin on mitochondrial function of differentiated murine e mbryonic stemcells(mESCs).METHODS Duringdifferentiationat24,72and120h,ESCswereexposedto T-2 toxin 0.5 μg·L-1 .Meanwhile,mESCs were pre-treated with antioxidant Trolox (200 μmol·L-1 )for 30 min and exposed to T-2 toxin (0.5 μg·L-1 )for 72 h.The mitochondrial ultrasture of differentiated mESCs was observed under a transi mission electrical microscope (TEM).The differentiated ESC mito-chondrial function,including respiratory control ratio (RCR),ATP synthase activity and mitochondrial membranepotential(MMP),wasmeasuredat144hafterdifferentiation.RESULTS Significant decrease of the mitochondrial number,deformation of mitochondrial structure,and lack of complete mito-chodrial crest were observed through TEM in the groups of T-2 toxin exposed for 72 and 1 20 h,respec-tively.Compared with the normal control group,RCR declined by 49.5% and 55.1%,ATP synthase activity decreased by 84.9% and 89.3%,and MMP decreased by 23.2% and 35.2% in T-2 toxin 0.5 μg·L-1 exposure 72 and 1 20 h group,respectively.However,the inhibition of mitochondrial function by T-2 toxin in differentiated mESCs recovered significantly in the presence of the antioxidant Trolox. CONCLUSION T-2toxininducesoxidativestressandinhibitsmESCsmitochondrialfunctionindifferenti-ated mESCs,and ROS-induced mitochondrial malfunction plays an i mportant role in T-2 toxin e mbryonic toxicity mechanis m.

Regulatory role of metallothionein in process of ischemic brain injury / 中国药理学与毒理学杂志

Metallothionein ( MT ) is a cysteine-rich and low-molecular metal binding protein. Three isoforms of MT have been found in the central nervous system, including MT-Ⅰ, Ⅱ, and Ⅲ. MT is widely involved in many critical activities in the central nervous system, such as neuronal growth, auto-defensive reaction, immune-regulation, and repair of cerebral injury. MT exerts many important biological functions like scavenging of free radicals, regulation of ion homeostasis in brain cells, detoxification of heavy metals, anti-inflammation, and anti-apoptosis. Recently, MT has been increasingly shown to have protective effects against cerebral ischemia. MT promises to be an important target for prevention and/or treatment of cerebral ischemic disease. ln this review, the expression and regulation characteristics, and the effect of cerebral ischemic stress on MT expression have been summarized, with focus on the neuro-protective effect of MT and its possible underlying mechanisms.

Comparative study on metabonomics and on liver and kidney toxicity of Aristolochia fangchi and Stephania tetrandra / 中国中药杂志

<p><b>OBJECTIVE</b>Combined the blood biochemical markers, the renal histopathological changes and the metabonomics profile were investigated to study the toxicity differences between Aristolochia fangchi and Stephania tetrandra.</p><p><b>METHOD</b>Ten rats were randomly selected from 70 male Wistar rats as blank control group. The remaining 60 rats were divided into three groups. The two treated groups were orally administrated by 8.1 g x kg(-1) of A. fangchi and S. tetrandra respectively and the control group by equal volume of distilled water for 4weeks. Before the administrated and every 2 weeks, urine and plasma were collected and their 1H-NMR spectra were acquired, and then subjected to data process and PCA. Blood biochemical analysis and histopathological examination were carried out.</p><p><b>RESULT</b>On the 2nd weekend, the BUN of the two treated groups, the AST of A. fangchi group were all markedly higher than that of the control group (P < 0.05). Compared with the A. fangchi group, the SCr higher in the S. tetrandra group (P < 0.05). The kidney pathological changes were apparently in the two treated groups and the pathological changes in the liver apparently in the S. tetrandra group. Along with the lasting of administration to the 4th week, the BUN, ALT and AST of the two treated groups, the SCr of A. fangchi group were all significantly higher than that of the control group (P < 0.01). The renal and liver injuries in the two treated groups were all become more seriously. Comparing the A. fangchi group, the BUN, SCr and AST were all higher in the S. tetrandra group (P < 0.05). Compared with control group, the urinary concentrations of citrate, 2-oxo-glutarate, taurine, hippurate, TMAO, creatine and the plasma concentrations of 3-D-hydroxybutyrate, acetone, NAC, OAC, creatinine were all changed.</p><p><b>CONCLUSION</b>The A. fangchi and S. tetrandra all can induce the renal and liver lesion and its seriousness is correspondent to the lasting of administration. The liver and kidney toxicity of S. tetrandra are all more serious than the A. fangchi.</p>

Nephrotoxicity study of Aristolochia fangchi in rats by metabonomics / 中西医结合学报

To study the changes of metabolites in rat urine after treatment of Aristolochia fangchi decoction by metabonomic method.

Cytotoxicity evaluation of a novel anticholinergic drug penehyclidine hydrochloride and its optical isomers / 中国临床药理学与治疗学

AIM: To evaluate the cytotoxicity of a novel anticholinergic drug penehyclidine hydrochloride (PHC) and its four optical isomers R-1, R-2, S-1, and S-2. METHODS: Two in vitro assays, MTT assay and neutral red uptake assay, were used to evaluate the cytotoxicity following PHC and its isomers exposure to HepG2 cells at different concentrations. RESULTS: PHC and its isomers induced decreases of viability of HepG2 cells in a concentration-dependent manner. Comparison of the cytotoxicity of the five anticholinergic agents with 50% inhibitory concentration (IC50) values indicated that the order of potency was PHC>R-2>R-1>S-2>S-1 for MTT assay, and R-2>PHC≈R-1>S-2>S-1 for neutral red uptake assay. CONCLUSION: With respect to the cytotoxicity of the four isomers on HepG2 cells, the R configuration was more potent than the S configuration, and R-2 was the most potent isomer whereas S-1 was the least potent isomer among the four optical isomers.

Protective effects of metallothionein induced by zinc against doxorubicin-caused cardiotoxicity and its potential mechanisms / 中国新药与临床杂志

AIM: To investigate the effects of metallothionein (MT) induced by zinc on doxorubicin (DOX)-treated mice and to explore the potential mechanisms. METHODS: Male C57BL/6J mice were divided randomly into 4 groups (n = 6) following control, DOX, Zn and Zn plus DOX. Mice were pretreated with eikg-1, ip) or equal volume of saline, and were killed on d 4 after the last injection. Serum and hearts were collected for examination. RESULTS: Zinc pretreatment elevated cardiac MT levels significantly while other antioxidants in heart including glutathione (GSH), glutathione peroxidase (GSHpx) , superoxide dismutase (SOD), and catalase (CAT) were not altered. Severe oxidative injury occurred in the mice treated with DOX as myocardial lipid peroxidation and morphological changes manifested by myocardial fibers swelling and vacuolization and nuclear condensation or dissolution, with increased activities of serum creatine kinase and lactate dehydrogenase and depletion of GSH, GSHpx, and SOD while CAT activity was increased in compensation. However, pre-induction of MT with zinc attenuated all of these toxic changes significantly. Furthermore, DOX induced elevation of hydrogen peroxide in heart tissues was greatly inhibited by zinc pretreatment. CONCLUSION: Preinduction of MT by zinc protects the heart from DOX-induced cardiotoxicity, and this effect is possibly correlated with the property of MT on scavenging free radicals in vivo.

Biological Characteristics of Acid Sensing Ion Channels (ASICs) and Their Modulations / 生物化学与生物物理进展

ASICs are H+-gated novel cation ion channels, which belong to the epithelial sodium channels (NaC/DEG) superfamily. As recent studies focus, ASICs are expected to be pharmacological targets on protecting the neuron from ischemia and damage, improving the ability of memory and study, curing epilepsy and analgesia. It is not until the most recentness that the subunits of ASICs have been cloned. Now, researchers have paid more attention to the distribution, expression, function and modulation of ASICs in the organism.

The cytotoxicity of maitotoxin to LLC-PK(1) and its antagonism to calcium channel blocking agents / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the cytotoxicity of maitotoxin (MTX) and its protective effects on calcium-channel blocking agents, so as to provide the data for control and treatment of MTX poisoning.</p><p><b>METHODS</b>Cytotoxicity was measured by MTT detecting system, and cytoplasmic free [Ca(2+)]i was measured by F-4500 fluorometry.</p><p><b>RESULTS</b>Incubation with 8 ng/ml MTX for 3 h reduced the survival ratio of LLC-PK(1) cells. The response was found in a time- and concentration-dependent manner, with significant differences as compared with the control group. The MTX-induced increase in [Ca(2+)]i was inhibited by Verapamil and Nifedipine at 5 x 10(-5) mol/L and 1 x 10(-4) mol/L respectively. Both of them significantly reduced the death of the LLC-PK(1) cells.</p><p><b>CONCLUSIONS</b>Cytotoxicity of MTX may be caused by the elevated intracellular [Ca(2+)]i. Calcium-channel blocking agents could protect LLC-PK(1) cells from injury by MTX.</p>

Induction of Micronuclei in HepG2 Cell line by Dichlorvos,Dimethoate and Malathion / 环境与健康杂志

Objective Micronucleus test(MNT) was used to evaluate the single and combined genotoxicity of dichlorvos(DDVP),dimethoate(DM) and malathion(Mal) in HepG2 cell line,and 2?2 factorial design was adopted to elucidate the combined genotoxic effects.Methods In cytotoxicity test,HepG2 cells were exposed to the three OPPs(DDCP,DM,Mal) for 4 h respectively,and the doses at which cell viability above 80% were selected for the MNT,DDVP:3.125-25 ?g/ml,DM:25-200 ?g/ml,Mal:50400 ?g/ml,the micronucleated cell(MNC) rates and the replicative index(RI) were calculated.The combined genotoxicity of them was investigated with their doses as follows:low dose(DDVP:3.125 ?g/ml,DM:25 ?g/ml,Mal:50 ?g/ml);high dose(DDVP:12.5 ?g/ml,DM:100 ?g/ml,Mal:200 ?g/ml).Results In MNT,after treatment of HepG2 cells with DDVP,DM or Mal alone for 4 h,the MNC rates were increased in a dose-response manner(DDVP:r=0.955,P

Calcium homeostasis deregulation in glutamate-induced excitotoxicity and its role in neurodegenerative diseases / 中国药理学通报

Excitotoxicity refers to a process of neuronal death caused by excessive or prolonged activation of receptors for the excitatory amino acids, which is related to the overload of intracellular calcium ([Ca2+]i) and mitochondrial depolarization. The well accepted hypothesis that Ca2+ plays a central role in neurotoxicity, and it mediated excitotoxicity is deeply involved in both acute and chronic neurodegeneration suggests that inhibitors of Ca2+ transduction, such as NMDA antagonists, might block the pathological process at an early stage and provide more effective protections.