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The aim of this paper was to assess the influence of Fasciola hepatica infection on oxidative modifications of rat liver cell components such as proteins and lipids. Wistar rats were infected per os with 30 metacercariae of F. hepatica. Activities and concentrations of liver damage markers were determined in the 4th, 7th, and 10th week postinfection (wpi). A decrease in antioxidant capacity of the host liver, manifested by a decrease in total antioxidant status (TAS), was observed. Diminution of antioxidant abilities resulted in enhanced oxidative modifications of lipids and proteins. F. hepatica infection enhanced lipid peroxidation, which was visible in the statistically significant increase in the level of different lipid peroxidation products such as conjugated dienes (CDs), lipid hydroperoxides (LOOHs), malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). The level of protein modification markers in the rat liver was also significantly changed and the most intensified changes were observed at seventh week postinfection. Concentration of carbonyl groups and dityrosine was significantly increased, whereas the level of tryptophan and sulfhydryl and amino groups was decreased. Changes in the antioxidant abilities of the liver and in the lipid and protein structure of the cell components resulted in destruction of the function of the liver. F. hepatica infection was accompanied by raising serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as markers of liver damage. A significant decrease in lysosomal as well as in the total activity of cathepsin B during fasciolosis was also observed. [ABSTRACT FROM AUTHOR]

Ethanol introduced into the organism undergoes rapid metabolism to acetaldehyde and then to acetic acid. The process is accompanied by formation of reactive oxygen species (ROS), which damage mainly lipids of membrane cells. The effects of ROS can be neutralized by administering preparations with antioxidant properties. The natural preparations of this kind are teas. This paper reports data on the effect of green and black tea on the surface charge density, content of phospholipids, and level of lipid peroxidation products of liver cell membrane of rats chronically intoxicated with ethanol. Surface charge density of liver cells was measured by the electrophoresis method, whereas qualitative phospholipid composition was determined by the HPLC method. Ethanol administration caused an increase in the amount of all phospholipids, in surface charge density as well as in lipid peroxidation products. Ingestion of green and black tea with ethanol partially prevented these ethanol-induced changes, and the action of green tea was stronger than that of black tea. [ABSTRACT FROM AUTHOR]

Aflatoxin B1 (AFB1) can cause hepatocellular carcinoma (HCC) through a mutagenic mode of action but can also lead to global changes in gene expression; however, the AFB1 network of molecular pathways involved in HCC is not known. Here, we used toxicogenomic data from human liver cells exposed to AFB1 to infer the network of AFB1-responsive molecular pathways involved in HCC. The following computational tools: STRING, MCODE, cytoHubba, iRegulon, kinase enrichment tool KEA3, and DAVID were used to identify protein-protein interaction network, hub genes, transcription factors (TFs), upstream kinases, and biological processes (BPs). Predicted molecular events were validated with an external dataset, whereas the hub genes in HCC were validated using the UALCAN database. The results revealed an association between AFB1 and the hub genes involved in the cell cycle. We identified TFs that regulate the hub genes and linked them with upstream kinases including cyclin-dependent kinases, mitogen-activated protein kinase 1, and AKT. This approach enabled the construction of the AFB1-mediated regulatory network consisting of upstream kinases, TFs, hub genes, and BPs, thus revealing the signaling hierarchy and information flow that may contribute to AFB1-induced HCC. This could be a useful tool in predicting the molecular mechanisms involved in chemical-induced diseases when available toxicogenomic data exist. [ABSTRACT FROM AUTHOR]

As a pesticide extracted from plants, rotenone is widely used to control plant pests. In order to explore the safety of rotenone in the environment, we took 60 healthy male SD rats and randomly divided them into rotenone low-dose group, rotenone medium-dose group, rotenone high-dose group, dimethyl sulfoxide group (DMSO), and control group. After 28 days of oral administration, the rat liver tissue ultrastructure, liver function, oxidative stress indexs, mitochondrial function, and apoptosis-related factors were tested to evaluate the hepatotoxicity and toxicological mechanism of rotenone. The results showed that rotenone significantly increased the hepatic index of rats and the activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum. Rotenone can reduce the number of endoplasmic reticulum of hepatocyte, concentrate chromatin and make the hepatocyte nuclears irregular. Rotenone weakened the ATP synthesis ability in mitochondria, decreased the activity of ATP enzyme in mitochondria, and increased the mitochondrial membrane potential in the high-dose group. And it induced oxidative stress damage to the mitochondria of rat liver cells. Rotenone can upregulate the expression of pro-apoptotic factors and downregulate the expression of anti-apoptotic factors. These results indicate that oral rotenone in rats induced hepatotoxicity in a dose-dependent manner. The mechanism of rotenone poisoning is that oxidative stress damages organelles of hepatocyte such as mitochondria and endoplasmic reticulum, resulting in their function being weakened or lost, leading to hepatocyte apoptosis. [ABSTRACT FROM AUTHOR]

Predicting drug-induced liver injury is important in early stage drug discovery; however, an accurate prediction with existing hepatotoxicity evaluation tools is difficult. Conventional monolayer (2D) cultures have short viabilities and are therefore inappropriate for performing long-term toxicity tests. Conventionally used 200-μm spheroids also have toxicity detection limits. The goal of this study was to develop a humanized liver tissue capable of evaluating long-term toxicity with high sensitivity. Spheroids consisting of co-cultured cryopreserved primary human hepatocytes and human hepatic stellate cells were developed using a 3D bio-printer. The "3D bio-printed liver tissue", of ∼1 mm, was then used for long-term viability assessments (over 25 days) based on ATP, albumin, and urea levels. Hepatotoxicity evaluation was performed by analyzing the expression of genes involved in drug metabolism and transport over a 2-week drug exposure period. The 3D bio-printed liver tissue showed improved viability and enhanced gene expression of enzymes related to drug metabolism and transport, as compared to the controls. Additionally, the 3D bio-printed liver tissue demonstrated a high sensitivity for hepatotoxicity evaluation when combined with pathological evaluation and measurements for ATP production, and secretion of albumin and urea. In conclusion, the 3D bio-printed liver tissue was able to detect the toxicity of compounds that was, otherwise, undetected by 2D culture and conventionally used spheroids. These findings demonstrate a 3D bio-printed liver tissue with increased accuracy of hepatotoxicity prediction in the early stages of drug discovery, as compared to currently available methods. [ABSTRACT FROM AUTHOR]

The possible molecular mechanisms of Nano-selenium (nano-se) in attenuating hepatocellular carcinoma (HCC) was investigated in this study. To achieve this target, the apoptotic/necrotic rate in hepatic cells was investigated morphologically by double staining with acridine orange/ethidium bromide to address the type of cell death induced by nano-Se in HCC-bearing rats. To predict the oxidative stress and DNA damage, the generation of 8-hydroxy-2-deoxyguanosine (8-OHdG) and 2-deoxyguanosine (2-dG) was examined. Moreover, the expression of some HCC-related genes was investigated such as aldo-keto reductase 1B10 ( Akr1b10), ING3 and Foxp1 genes. As well as the histopathological study of liver tissue sections was performed. The results obtained from this study revealed that (HCC+Nano Se) group shows the highest number of damaged cancerous cells. Furthermore, the necrotic/apoptotic rate was significantly higher in (nano-Se+HCC), (HCC+Doxo) and (HCC+Doxo+nano-se) compared to that in the untreated HCC group. Treatment of HCC group with nano-se decreased the ratio of 8-OHdG/2-dG generation significantly with respect to the untreated HCC group. The opposite was observed regarding the gene expression of AKr1b10 and ING3. The treatment of HCC group with nano-se elicited significant increase in the expression of Akr1b10 and ING3 genes compared with untreated HCC group. On the other hand, the expression of Foxp1 gene was significantly decreased in HCC group treated with nano-se in comparison with the untreated HCC group. The histopathological study provided a supportive evidence for the molecular genetics study. Our data shed light on the molecular mechanisms of nano-se in attenuating HCC in the experimental model. [ABSTRACT FROM AUTHOR]

Massive application of pesticides had generated a considerable concern in the public. Potentials of chlorpyrifos [ O,O-diethyl- O-(3,5,6-trichloro-2-pyridinyl) phosphorothionate] and cypermethrin [( RS)- α-cyano-3-phenoxybenzyl (1 RS)- cis- trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate] to induce the excision-repairable DNA damage, DNA strand breakage, and DNA hypomethylation in ICR mouse hepatocytes were investigated. It was showed that chlorpyrifos and cypermethrin didn't increase the incorporation of 3H-TdR into DNA of ICR mouse hepatocytes but increased the frequency of comet cells and decreased the 5MeC percentage of ICR mouse hepatocytes. In conclusion, chlorpyrifos and cypermethrin induced no excision-repairable DNA damage but led to DNA strand breakage and DNA hypomethylation in ICR mouse hepatocytes. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of fenugreek seed polyphenolic extract (FPEt) on ethanol-induced protein expression in Chang liver cells. Cells were incubated with either 30 mM EtOH alone or together in the presence of FPEt for 24 h. Cells were harvested and assessed for expression of alcohol metabolizing enzymes-alcohol dehydrogenase (ADH2 isoform), aldehyde dehydrogenase (ALDH2 isoform), cytochrome P450 (CYP2E1), the electron transport component (cytochrome-c), and the heat shock proteins. The expression of ADH2, ALDH2, and CYP2E1 were upregulated, whereas the expression of cytochrome-c was downregulated in the ethanol-treated cells. The expression of cellular heat shock proteins-HSP70, HSC70, HSC92, and mitochondrial protein mtHSP70 were induced in ethanol-treated Chang liver cells. FPEt modulated the protein expression changes induced by ethanol and had no effect when incubated with normal Chang liver cells. FPEt might exert cytoprotective action on ethanol-induced liver cell damage, possibly by enhancing cellular redox status. [ABSTRACT FROM AUTHOR]

This study is aimed to evaluate the role of intracellular GSH in pyrrolizidine alkaloid clivorine-induced toxicity on human normal liver L-02 cells. Clivorine induced profound intracellular GSH depletion in a concentration-dependent manner. The GSH synthesis inhibitor L-Buthionine (S, R)-sulfoximine (BSO) significantly potentiated toxicity of clivorine, while GSH and GSH synthesis precursors N-Acetyl-L-cysteine (NAC) and S-adenosyl-L-methionine (SAM) protected cells against toxicity of clivorine. Overall, the results suggest that intracellular GSH plays an important role in the toxicity of clivorine on human hepatocytes. [ABSTRACT FROM AUTHOR]

During the last years, much attention was focused on the measurement of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxo-dG) as a marker of oxidative DNA damage. Among various analytical techniques, the 32 P-postlabeling assay has been applied in determination of 8-oxo-dG. However, artefactual DNA oxidation could take place during the work-up procedures leading to over-estimate the level of 8-oxo-dG. In the present study, we optimized the 32 P-postlabelling assay with thin layer chromatography to measure 8-oxo-dG in standard samples of 8-oxo-dG, calf thymus DNA and primary cultured rat hepatocytes. The background levels of 8-oxo-dG in calf thymus DNA and in primary cultured rat hepatocytes were lesser than those determined by the previously described 32 P-postlabeling procedures and were in the range of those determined by chromatography methods (GC-MS, HPLC-MS). [ABSTRACT FROM AUTHOR]