In Vitro Toxicity to Two Cellular Systems of the First Ten Chemicals on the MEIC List

1990 ◽  
Vol 17 (3) ◽  
pp. 218-223
Author(s):  
Xavier Ponsoda ◽  
Ramiro Jover ◽  
José Vicente Castell ◽  
Mariá José Gómez-Lechón

The cytotoxic effects of the first 10 chemicals on the MEIC list were evaluated with two experimental cellular systems, monolayer cultures of rat hepatocytes and cell lines (Hep G2 and 3T3). Three endpoints were measured to evaluate cytotoxicity, intracellular LDH activity, cellular protein content and the MTT test. The results show that: 1. digoxin, amitriptyline and diazepam were the most cytotoxic chemicals (IC50:0.01-0.5mM); 2. alcoholic compounds (sopropanol, ethylene glycol, ethanol and methanol) produced the lowest toxic effects (IC50: 100–1500mM); 3. paracetamol, acetylsalicylic acid and ferrous sulphate showed an intermediate cytotoxic action (C50: 0.05–15mM); 4. regarding the sensitivity of the cellular systems, paracetamol, acetylsalicylic acid, diazepam and ferrous sulphate were more toxic to rat hepatocytes, while digoxin produced a different toxic effect on hepatic and non-hepatic cells; and 5. the other chemicals did not show significant differences in their toxicity in the different cellular systems studied.

2007 ◽  
Vol 26 (4) ◽  
pp. 333-338 ◽  
Author(s):  
Anna Forsby ◽  
Bas Blaauboer

Risk assessment of neurotoxicity is mainly based on in vivo exposure, followed by tests on behaviour, physiology and pathology. In this study, an attempt to estimate lowest observed neurotoxic doses after single or repeated dose exposure was performed. Differentiated human neuroblastoma SH-SY5Y cells were exposed to acrylamide, lindane, parathion, paraoxon, phenytoin, diazepam or caffeine for 72 hours. The effects on protein synthesis and intracellular free Ca2+concentration were studied as physiological endpoints. Voltage operated Ca2 +channel function, acetylcholine receptor function and neurite degenerative effects were investigated as neurospecific endpoints for excitability, cholinergic signal transduction and axonopathy, respectively. The general cytotoxicity, determined as the total cellular protein levels after the 72 hours exposure period, was used for comparison to the specific endpoints and for estimation of acute lethality. The lowest concentration that induced 20% effect (EC 20) obtained for each compound, was used as a surrogate for the lowest neurotoxic level (LOEL) at the target site in vivo. The LOELs were integrated with data on adsorption, distribution, metabolism and excretion of the compounds in physiologically-based biokinetic (PBBK) models of the rat and the lowest observed effective doses (LOEDs) were estimated for the test compounds. A good correlation was observed between the estimated LOEDs and experimental LOEDs found in literature for rat for all test compounds, except for diazepam. However, when using in vitro data from the literature on diazepam's effect on gamma-amino butyric acid (GABA)A receptor function for the estimation of LOED, the correlation between the estimated and experimental LOEDs was improved from a 10 000-fold to a 10-fold difference. Our results indicate that it is possible to estimate LOEDs by integrating in vitro toxicity data as surrogates for lowest observed target tissue levels with PBBK models, provided that some knowledge about toxic mechanisms is known. Human & Experimental Toxicology (2007) 26, 333—338


2018 ◽  
Vol 17 (3) ◽  
pp. 6-11
Author(s):  
M. P. Klantsa ◽  
I. Ye. Herasymyuk

According to the results of the study, it has been established that chronic acetylsalicylic acid poisoning results in severe liver disorders presented by both venous and portal blood overloaded with a reflex throughput decrease of the arterial part of the bloodstream. Prolonged venous stasis and reflex vasoconstriction of arteries lead to ischemia of the liver tissue with the development and progression of dystrophic changes in hepatocytes. With an increase in the duration of observation, there is an expansion of cell zones with signs of granular dystrophy, which pass into fields with dystrophy of hepatic cells, damage of intercellular boundaries, homogenization of cytoplasm and degradation of nuclei of hepatocytes. It was manifested quantitatively by an increase in the cross-section of hepatocytes and their nuclei with an appropriate dynamics of nuclear-cytoplasmic relations.


1971 ◽  
Vol 124 (2) ◽  
pp. 385-392 ◽  
Author(s):  
R. W. Wannemacher ◽  
C. F. Wannemacher ◽  
M. B. Yatvin

Weanling (23-day-old) rats were fed on either a low-protein diet (6% casein) or a diet containing an adequate amount of protein (18% casein) for 28 days. Hepatic cells from animals fed on the deficient diet were characterized by markedly lower concentrations of protein and RNA in all cellular fractions as compared with cells from control rats. The bound rRNA fraction was decreased to the greatest degree, whereas the free ribosomal concentrations were only slightly less than in control animals. A good correlation was observed between the rate of hepatic protein synthesis in vivo and the cellular protein content of the liver. Rates of protein synthesis both in vivo and in vitro were directly correlated with the hepatic concentration of individual free amino acids that are essential for protein synthesis. The decreased protein-synthetic ability of the ribosomes from the liver of protein-deprived rats was related to a decrease in the number of active ribosomes and heavy polyribosomes. The lower ribosomal content of the hepatocytes was correlated with the decreased concentration of essential free amino acids. In the protein-deprived rats, the rate of accumulation of newly synthesized cytoplasmic rRNA was markedly decreased compared with control animals. From these results it was concluded that amino acids regulate protein synthesis (1) by affecting the number of ribosomes that actively synthesize protein and (2) by inhibiting the rate of synthesis of new ribosomes. Both of these processes may involve the synthesis of proteins with a rapid rate of turnover.


2000 ◽  
Vol 19 (5) ◽  
pp. 309-317 ◽  
Author(s):  
M I Grant ◽  
K Anderson ◽  
G McKay ◽  
M Wills ◽  
C Henderson ◽  
...  

The liver-specific phenotype of immortalised rat hepato-cytes is not irretrievably lost as they age in culture but can be manipulated by modifying the culture environment. Testosterone metabolism was used to investigate the profile of cytochrome P450 isoenzymes present in two immortalised cell lines, P9 and LQC, and in primary cultures of rat hepatocytes, cultured on collagen films, gels and double gel cultures (sandwich configuration). The extent of testosterone metabolism, and the range of metabolites produced, was increased in immortalised cells by the presence of collagen as a substratum film or gel but survival was poorer and the range of metabolites was reduced in sandwich culture. In contrast, testosterone metabolism was retained in primary hepatocytes in sandwich cultures at a higher level than in collagen film or gel cultures. Expression of alpha class glutathione-S-transferases (GSTs) increased and that of GSTP1 decreased (changes which indicate a recovery of normal liver GST phenotype) when the medium of immortalised cell cultures was supplemented with dimethyl sulph-oxide (DMSO). DMSO also improved ethoxyresorufin 0-deethylation (EROD) and testosterone metabolism in immortalised cells. It also markedly inhibited prolifera-tion, DNA, RNA and protein synthesis. Maximal testosterone metabolism was observed in immortalised cells cultured on collagen gels in the presence of l1o (v/v) DMSO. Development of a protocol for treating immortalised liver cells cultured on collagen gels with DMSO to switch between proliferation and differentiation may provide a convenient system expres-sing the xenobiotic metabolising enzymes required for in vitro toxicity testing.


Hepatology ◽  
1988 ◽  
Vol 8 (6) ◽  
pp. 1673-1678 ◽  
Author(s):  
Philippe Mavier ◽  
Bernard Guigui ◽  
Anne-Marie Preaux ◽  
Jean Rosenbaum ◽  
Marie-Claude Lescs ◽  
...  

2016 ◽  
Vol 60 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Lidia Radko ◽  
Maria Minta ◽  
Sylwia Stypuła-Trębas

Abstract Introduction: The cytotoxicity of anthelmintic agent, albendazole (ABZ) and its two major metabolites, sulfoxide (ABZSO) and sulfone (ABZ-SO2), on non-hepatic Balb/c 3T3 line, two hepatoma cell lines (FaO, HepG2), and isolated rat hepatocytes was investigated. Material and Methods: Cell cultures were exposed for 24, 48, and 72 h to eight concentrations of the compounds ranging from 0.05 to 100 μg/mL (ABZ) and from 0.78 to 100 μg/mL (ABZ-SO and ABZ-SO2). Three different assays were applied in which various biochemical endpoints were assessed: lysosomal activity - neutral red uptake (NRU) assay, proliferation - total protein contents (TPC) assay and lactate dehydrogenase (LDH) leakage assay. Results: The most toxic was albendazole whose EC50 values calculated from the concentration effect curves ranged from 0.2 to 0.5 μg/mL (Balb/c 3T3 ) and from 0.4 to 73.3 μg/mL (HepG2). Rat hepatoma line and isolated rat hepatocytes were less sensitive to the impact of ABZ. Toxic action expressed as EC50 was recorded after 72 h exposure only in LDH release assay at 0.8 μg/mL and 9.7 μg/mL respectively. The toxicity of metabolites was much lower. The most sensitive to ABZ-SO were fibroblasts and EC50-72h values were similar in all three assays used, i.e. NRU (14.1 μg/mL), TPC (15.8 μg/mL), and LDH (20.9 μg/mL). In the case of ABZ-SO2 the mean effective concentrations were the highest, and could be reached only in one LDH assay. These values (μg/mL) were as follows: 65.3 (FaO), 65.4 (HepG2), 75.8 (hepatocytes), and 77.4 (Balb/c 3T3). Conclusion: The differences in in vitro toxicity of albendazole depend on metabolic ability of the cellular models. Primary cultured rat hepatocytes represent a valuable tool to study the impact of biotransformation on the cytotoxicity of drugs.


1990 ◽  
Vol 15 (3) ◽  
pp. 145-156 ◽  
Author(s):  
Akiko KAWAJI ◽  
Tomomichi SONE ◽  
Reiko NATSUKI ◽  
Masakazu ISOBE ◽  
Eigo TAKABATAKE ◽  
...  

2002 ◽  
Vol 21 (1) ◽  
pp. 43-48 ◽  
Author(s):  
N Somchit ◽  
S M Hassim ◽  
S H Samsudin

This current study was to investigate the in vitrocytotoxicity of rat hepatocytes induced by the antifungal drugs, itraconazole and fluconazole. Both antifungal drugs caused dose-dependent cytotoxicity. In vitro incubation of hepatocytes with itraconazole revealed significantly higher lactate dehydrogenase (LDH) leakage when compared to fluconazole. Phenobarbital pretreated hepatocytes contained significantly higher total cytochrome P450 content than the control hepatocytes. P450 content was reduced approximately 30% for both types of hepatocytes after 6 hours incubation. Interestingly, cytotoxicity of itraconazole was reduced significantly by phenobarbital pretreatment. Phenobarbital did not have any effect on the cytotoxicity induced by fluconazole. These results demonstrate the in vitro toxicity of hepatocytes induced by itraconazole and fluconazole that were expressed in a dose and time-dependent manner. Phenobarbital plays a role in the cytoprotection of hepatocytes to itraconazole-induced but not fluconazole-induced cytotoxicity in vitro.


Author(s):  
M A Akanji

Mitochondria and lysosome have been used to study drug-cell interactions both in vitro and in vivo. However, their preparations to free them from other sub-cellular organelles are tedious and cumbersome. Erythrocytes (being a simple type of cells without sub-cellular organelles and very easy to obtain in pure form) was assessed for in-vitro toxicity testing of selected chemical compounds by monitoring the release of its hemoglobin content as an index of damage to cell membrane. Washed erythrocytes from male wistar rats were prepared in sodium phosphate buffer (pH 7.5) incubated with and without acetylsalicylic acid (a membrane stabilizer) and chloroquine (a membrane labilizer). The light scattering properties of the suspensions and the hemoglobin released were determined using standard methods. Acetylsalicylic acid did not significantly alter the degree of hemolysis (P > 0.05) whereas the chloroquine alone as well as the mixture of acetylsalicylic acid and chloroquine significantly increased (P < 0.05) it. Acetylsalicylic acid stabilized the erythrocytes membrane while chloroquine destroys it causing lysis of the cell membrane. Results obtained in this study suggest that the drugs have interacted with the erythrocytes in a manner that corresponds to their mode of action. Erythrocytes can therefore be used to study interactions between drug molecules and cell membrane.


1989 ◽  
Vol 35 (11) ◽  
pp. 1000-1008 ◽  
Author(s):  
A. Vey ◽  
J. M. Quiot

The cytotoxic effect of the cyclodepsipeptide mycotoxins of the group of destruxins (DA, DB, DE) has been investigated in the insect host, Galleria mellonella, and in invertebrate cell cultures, mainly at the ultrastructural level. The strong effect of DE is characterized by changes in the morphology of the cells, and the development of structural alterations at the nuclear and cytoplasmic levels. The major lesions observed even at low doses consist in a pycnotic evolution of the nucleus and a degradation of mitochondria, while the rough endoplasmic reticulum and the ribosomes are also impaired. In the host, the main organs and tissues attacked by DE are the midgut, the malpighian tubules, and the circulating hemocytes. A comparative study of the effect of DE, DA, and DB has revealed a specificity in the cytotoxic action of these compounds. The following classification has been observed in the efficiency of the molecules: DE > DA > DB. These results allow a better understanding of the role of peptidic mycotoxins in the pathogenesis of fungal infections. They also reveal similarities with the action of other mycotoxins, and constitute a valuable foundation for studies on the molecular aspects of the mechanism of action of destruxins.Key words: mycotoxin, destruxin, mode of action, cytotoxic effect, in vitro toxicity.


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