Human & Experimental Toxicology

Siqian, L; Lei, S; Ying, L

doi: 10.1177/0960327115621364pmid: 26721909

Abstract Objective: To develop a mouse cell biosensor system for the high-throughput genotoxicity detection of chemicals, such as environmental pollutants. Method: We developed a novel reporter vector pGL4-GFP, wherein the firefly luciferase reporter gene in the pGL4.82 vector was replaced by the green fluorescent protein (GFP) gene from the pAcGFP1-N1 vector. To construct the reporter pGL4-p53-GFP (p53 promoter linked to GFP), a fragment containing the p53 gene promoter was generated by amplifying a region from −481 to +180 of mouse genomic DNA isolated from mouse tail tissue. We developed a mouse cell biosensor system for the high-throughput genotoxicity detection of new drugs by stably integrating the reporter plasmid of pGL4-p53-GFP into the mouse embryonic fibroblast cells. Various genotoxic agents were used to treat this biosensor system. The resulting fluorescence was directly observed under a fluorescence microscope, and the GFP protein level was measured through Western blot analysis. Result: The biosensor system was treated with genotoxic agents, such as doxorubicin, cyclophosphamide, and benzo(a)pyrene. The GFP protein expression was significantly increased in cells exposed to genotoxic agents but negatively responded to the non-genotoxic agent dimethyl sulfoxide, thereby proving the specificity and sensitivity of the biosensor system. Conclusion: This novel in vitro biosensor system can be especially useful in genotoxicity detection.

Pourtaji, A; Robati, R Yazdian; Lari, P; Hosseinzadeh, H; Ramezani, M; Abnous, K

doi: 10.1177/0960327115619771pmid: 26721910

Abstract Aim: Diazinon (DZN) is one of the most important organophosphorus compounds used to control pests in agriculture in many countries. Several studies have shown that exposure to DZN may alter protein expression in the liver. In order to further investigate the mechanism of DZN toxicity, differentially expressed ATP-interacting proteins, following subacute exposure to toxin, were separated and identified in rat liver. Main methods: Male rats were equally divided into four groups: control (corn oil) and DZN (15 mg/kg) by gavage once a day for 4 weeks. After homogenization of liver tissue, lysates were incubated ATP-sepharose beads. After several washes, ATP-interacting proteins were eluted and separated on 2-D polyacrylamide gels. Deferentially expressed proteins were cut and identified using matrix-assisted laser desorption/ionization/time-of-flight and Mascot database. Identified proteins were classified according to their biological process using protein analysis through evolutionary relationships (PANTHER) Web site. Key finding: In this work, we showed that several key proteins involved in biological processes such as antioxidant system, oxidative stress, apoptosis, and metabolism were differentially expressed after subacute exposure to DZN.

Chen, Y; Wu, L; Wang, Q; Wu, M; Xu, B; Liu, X; Liu, J

doi: 10.1177/0960327115622258pmid: 26704364

Abstract Prussian blue nanoparticle (PBNP), a new type of theranostic nanomaterial, had been used for cancer magnetic resonance imaging and photothermal therapy. However, their long-term toxicity after short exposure in vivo was still unclear. In this study, we investigated the dynamic changes of the biochemical and immunity indicators of mice after PBNPs injection through tail vein. Histological results showed that the PBNPs were mainly accumulated in liver and spleen. In the spleen, we found the frequency of T cells was starting to decrease after 1 day of PBNPs injection, but then slowly recovered to normal level after 60 days of injection. Meanwhile, the frequency of T cells in the blood was firstly decreased after the PBNPs injection, and then the T cell frequency kept increasing and recovered back to normal levels after 7 days of injection. The serum indexes of liver functions (alanine transaminase, aspartate transaminase, total bilirubin, and alkaline phosphatase) increased rapidly to a relatively high level only after 1 h of injection, which meant certain acute liver damage, but these indexes were gradually decreased to normal levels after 60 days of injection. These results indicate that PBNPs have acute toxicity in vivo, however, their long-term toxicity after short-time exposure is low, which might provide guidance for further applications of PBNPs in future.

Muthu, R; Selvaraj, N; Vaiyapuri, M

doi: 10.1177/0960327115618245pmid: 26655637

Abstract Colorectal cancer (CRC) is a serious health problem throughout the world. 5-Flurouracil, the first-line chemotherapy of colorectal cancer often produces more toxicity to neighboring cells; however, it is still used for CRC treatment. To overcome this, umbelliferone (UMB), a less toxic bioflavonoid has been used to test its anticancer effects on animal model. The objective of the present study is to evaluate the anticancer activity of UMB on 1,2-dimethylhydrazine (DMH)-induced rat colon tumorigenesis to determine the development of aberrant crypt foci (ACF), agyrophylic nucleolar organizer regions (AgNORs), mast cell recruitment, pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and also study the expressions of inducible nitric oxide synthase, cyclooxygenase (COX)-2, and apoptotic markers. DMH-induced rats showed increased ACF number (incidence), multiplicity and its distribution, counts of AgNORs, mast cells, inflammatory markers and apoptotic proteins. Interestingly, UMB supplementation to DMH-induced rats (group 4) significantly (p < 0.05) suppressed ACF development, AgNORs, mast cells, and inflammatory markers and increased the apoptotic markers as compared to DMH-induced rats (group 2). We concluded that UMB is a potential anticancer agent that can be used for the prevention and treatment of CRC.

Chen, T; Wang, L; Chen, K; Qiu, S; Cen, X; Li, H; Hu, C

doi: 10.1177/0960327115622259pmid: 26699188

Abstract To provide support for future pharmacology and preclinical studies, we have established a stable nonhuman primate animal model to demonstrate the histopathological changes in the gastrointestinal tract following gamma ray irradiation. In this study, 12 healthy rhesus monkeys were divided into 2 groups (control and radiation groups). Animals in the radiation group were exposed to gamma rays (cobalt 60 source) at a dose level of 6.5 Gy total body irradiation bilaterally (i.e. 3.25 Gy on each side). Control animals were sham exposed using identical procedures. After a 5-day in-life observation period, gastrointestinal tract tissues (esophagus, stomach, duodenum, jejunum, ileum, colon, and rectum) were collected and fixed in 10% neutral-buffered formalin for subsequent hematoxylin and eosin and 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry processing. The results showed that the esophagus was undergoing degeneration without obvious inflammatory changes, while the stomach and duodenum exhibited both degeneration and inflammation. From the jejunum to the rectum, late-stage inflammation with glandular regeneration, as well as a high-level BrdU labeling index, was present.

Nielsen, VG

doi: 10.1177/0960327115621366pmid: 26666988

Abstract Thousands suffer poisonous snake bite, often from defibrinogenating species annually. Three rattlesnake species in particular, the timber rattlesnake, Eastern diamondback rattlesnake, and Southern Pacific rattlesnake, cause clinically relevant hypofibrinogenemia via thrombin-like activity in their venom. It has been demonstrated that iron (Fe) and carbon monoxide (CO) change the ultrastructure of plasma thrombi and improve coagulation kinetics. Thus, the present investigation sought to determine if pretreatment of plasma with Fe and CO could attenuate venom-mediated catalysis of fibrinogen via thrombin-like activity. Human plasma was pretreated with ferric chloride (0–10 μM) and CO-releasing molecule-2 (0–100 μM) prior to exposure to 2.5–10 μg/ml of venom obtained from the aforementioned three species of rattlesnake. Coagulation kinetics were determined with thrombelastography. All three snake venoms degraded plasmatic coagulation kinetics to a significant extent, especially diminishing the speed of clot growth and strength. Pretreatment of plasma with Fe and CO completely abrogated the effects of all three venoms on coagulation kinetics. Further in vitro investigation of other pit viper venoms that possess thrombin-like activity is indicated to see if there is significant conservation of venom enzymatic target recognition of specific amino acid sequences such that Fe and CO can reliably attenuate venom-mediated catalysis of fibrinogen. These data also serve as a rationale for future preclinical investigation.

Charehsaz, M; Onen-Bayram, FE; Sipahi, H; Buran, K; Giri, AK; Aydin, A

doi: 10.1177/0960327115621365pmid: 26666987

Abstract ALC67 is an N-acylated thiazolidine compound with promising anticancer activity that led to the recent discovery of a series of 3-propionyl thiazolidine-4-carboxylic acid ethyl esters as a family of novel antiproliferative agents. Since the mutagenic and genotoxic properties of marketed anticancer molecules constitute a main issue to be addressed, this study focused on the analysis of the mutagenicity, antimutagenecity, and genotoxicity of this molecule. The mutagenicity and antimutagenicity of ALC67 were evaluated by Ames test performed on Salmonella TA98 and TA100 strains. The genotoxicity of this molecule was investigated in the chromosomal aberration assay on human lymphocytes. All results revealed that the analyzed structure is not mutagenic in the two Salmonella strains tested and was not genotoxic in human lymphocytes in vitro. On the other hand, it showed a weak antimutagenic effect in these two bacterial strains. The above results indicate that after performing some more mutagenicity assays using the other recommended strains, this compound can be safely used for the development of new structures exhibiting anticancer activities.

Asadi, R; Afshari, R; Dadpour, B

doi: 10.1177/0960327115617229pmid: 26655638

Abstract Background: Disability weights (DWs) are used in disease burden studies, with the calculation of the weight of the disability as years lived with disability versus years of lost life accounting for mortalities. Currently, there is a single DW score available for poisoning, which is considered to be a single health state. This makes it difficult to evaluate the differing burdens of poisonings involving various substances/conditions in comparison with other health states in countries with different patterns of substance abuse. The aim of this study is therefore to estimate the DWs of 18 common poisonings based on the expert elicitation method. Methods: A panel of 10 medical clinicians who were familiar with the clinical aspects of different poisonings estimated the DWs of 50 health states by interpolating them on a calibrated Visual Analogue Scale. The DWs of some poisonings, such as alcohol, cannabis and heroin, had been estimated in previous studies and so were used to determine the external consistency of our panel. As a matter of routine, the DWs could vary on a scale between 0 (best health state) and 1 (worst health state). Results: Statistical analysis showed that both the internal (Cronbach’s α = 0.912) and external consistency of the panel were acceptable. The DWs for the different poisonings were estimated along a range from 0.830 for severe aluminium phosphide to 0.022 for mild benzodiazepine. Conclusions: Different poisonings should be weighted differently since they vary widely. Unfortunately, they are currently all weighted the same.