Hepatotoxicity In HepG2 Cells Research Articles

Chebulic Acid against t‐BHP‐induced effect via Modulations of Nrf2 and Its Related Enzymes in HepG2 cells

Chebulic acid, phenolic compound isolated from the ripe fruits of Terminalia chebular Retz. shows diverse biological effects. The purpose of this study is to investigate protective effects of chebulic acid against tert‐butyl hydroperoxide (t‐BHP) induced oxidative stress and its mechanism related to Nrf2 signal pathway in HepG2 cells. Chebulic acid attenuated cell death and production of reactive oxygen species in t‐BHP‐induced HepG2 cells and increased intracellular glutathione (GSH) content and the ratio of GSH to glutathione disulfide (GSSG). Chebulic acid also upregulated the activity of heme oxygenase‐1 (HO‐1). The treatment with chebulic acid increased the translocation of Nrf2 into the nucleus and the expression of Nrf2 target genes such as γ‐glutamate cysteine ligase and HO‐1 in a dose‐dependent manner. In addition, the exposure of chebulic acid enhanced the phosphorylation of mitogen‐activated protein kinases (MAPK). The overall result is that chebulic acid has cytoprotective effect on t‐BHP‐induced hepatotoxicity in HepG2 cells through Nrf2‐mediated antioxidant enzymes and MAPK.Support or Funding InformationThis work was supported by a Grant from the Institute of Life Science and Natural Resources, Korea University.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Detoxifying effect of pyridoxine on acetaminophen-induced hepatotoxicity via suppressing oxidative stress injury

The detoxifying effect of pyridoxine against acetaminophen (APAP)-induced hepatotoxicity was investigated. HepG2 cells were co-treated with APAP and pyridoxine to compare with betaine or methionine for 24 h. LDH, ALT and AST activities were measured to determine direct cells damage in vitro and in vivo. Lipid peroxidation, antioxidant enzymes activity, and glutathione level were measured. Cytochrome c releaseand procaspase-3, cleaved caspase-3, Bcl-2, or Bax protein levels were measured to determine APAP-induced apoptotic cell death. Pyridoxine treatment significantly increased cell viability and decreased leakage of LDH activity against APAP-induced hepatotoxicity in HepG2 cells. ALT and AST activities were dose-dependently reduced by pyridoxine treatment compared to APAP-treated group. Significant increases in activities of GST and GPx were observed after co-treatment with APAP and pyridoxine. Although APAP-induced Nrf2 and HO-1 expression levels were gradually reduced in HepG2 cells by pyridoxine treatment, induction of antioxidant enzymes activities were dose-dependently increased. These protected effects of pyridoxine against APAP-induced hepatoxicity were closely associated with suppression of APAP-induced oxidative stress and apoptotic cell death in HepG2 cells. These data indicated that the protective action of pyridoxine against hepatic cell injuries was involved in the direct antioxidant activity which provides a pivotal mechanism for its potential hepatoprotective action.

Modulation of miR-26a-5p and miR-15b-5p Exosomal Expression Associated with Clopidogrel-Induced Hepatotoxicity in HepG2 Cells.

Clopidogrel is an essential antiplatelet drug used to prevent thrombosis complications associated with atherosclerosis. However, hepatotoxicity is a potential adverse effect related to clopidogrel therapy. Exosome-derived miRNAs may be useful for improved monitoring of drug response and hepatotoxicity risk. In the present study, the expression of several exosomal miRNAs (miR-26a-5p, miR-145-5p, miR-15b-5p, and miR-4701-3p) and cell-derived mRNA targets (PLOD2, SENP5, EIF4G2, HMGA2, STRADB, and TLK1) were evaluated in HepG2 cells treated with clopidogrel (6.25, 12.5, 25, 50, and 100 μM) for 24 and 48 h. Then, clopidogrel cytotoxicity was evaluated by analyzing DNA fragmentation and the cell cycle profile using flow cytometry. Differential expression of exosome-derived miRNAs and cell-derived mRNAs was analyzed by RT-qPCR. Exposure of HepG2 cells to high concentrations of clopidogrel (50 and 100 μM) for 24 h caused significant DNA fragmentation (17.6 and 44.4%, respectively; p < 0.05) and 48 h (26.8 and 48.9%, respectively; p < 0.05), indicating cellular toxicity. Upregulation of miR-26a-5p and downregulation of miR-15b-5p was observed in cells exposed to 100 μM clopidogrel for 24 and 48 h. The miR-26a-5p target mRNAs HMGA2, EIF4G2, STRADB, and SENP5 were downregulated in HepG2 cells following exposure to cytotoxic concentrations of clopidogrel (50 and 100 μM) for 24 h, and HMGA2 levels remained low after 48 h of treatment. TLK1, a target of miR-15b-5p, was downregulated by 50 and 100 μM clopidogrel at 24 h. In conclusion, our results suggest that exposure to high concentrations of clopidogrel modulates the expression of exosomal miR-26a-5p and miR-15b-5p and their target mRNAs in HepG2 cells. Dysregulation of these miRNAs maybe modulate the regulatory pathways involved in clopidogrel-induced liver injury.

Hepaprotective Effect of StandardizedEcklonia stoloniferaFormulation on CCl4-Induced Liver Injury in Sprague-Dawley Rats

The liver is an essential organ for the detoxification of exogenous xenobiotics, drugs and toxic substances. The incidence rate of non-alcoholic liver injury increases due to dietary habit change and drug use increase. Our previous study demonstrated that Ecklonia stolonifera (ES) formulation has hepatoprotective effect against alcohol-induced liver injury in rat and tacrine-induced hepatotoxicity in HepG2 cells. This present study was designated to elucidate hepatoprotective effects of ES formulation against carbon tetrachloride (CCl4)-induced liver injury in Sprague Dawley rat. Sixty rats were randomly divided into six groups. The rats were treated orally with ES formulation and silymarin (served as positive control, only 100 mg/kg/day) at a dose of 50, 100, or 200 mg/kg/day for 21 days. Seven days after treatment, liver injury was induced by intraperitoneal injection of CCl4 (1.5 ml/kg, twice a week for 14 days). The administration of CCl4 exhibited significant elevation of hepatic enzymes (like AST and ALT), and decrease of antioxidant related enzymes (superoxide dismutase, glutathione peroxidase and catalase) and glutathione. Then, it leaded to DNA damages (8-oxo-2′-deoxyguanosine) and lipid peroxidation (malondialdehyde). Administration of ES formulation inhibited imbalance of above factors compared to CCl4 induced rat in a dose dependent manner. Real time PCR analysis indicates that CYP2E1 was upregulated in CCl4 induced rat. However, increased gene expression was compromised by ES formulation treatment. These findings suggests that ES formulation could protect hepatotoxicity caused by CCl4 via two pathways: elevation of antioxidant enzymes and normalization of CYP2E1 enzyme.

Protective effects of flavonoids isolated from Korean milk thistle Cirsium japonicum var. maackii (Maxim.) Matsum on tert-butyl hydroperoxide-induced hepatotoxicity in HepG2 cells

Ethnopharmacological relevanceMilk thistle leaves and flowers have been traditionally used as herbal remedy to alleviate liver diseases for decades. Korean milk thistle, Cirsium japonicum var. maackii (Maxim.) Matsum has been employed in traditional folk medicine as diuretic, antiphlogistic, hemostatic, and detoxifying agents. Aim of the studyThe aim of current investigation was to evaluate hepatoprotective properties of the MeOH extract of the roots, stems, leaves and flowers of Korean milk thistle as well as four isolated flavonoids, luteolin, luteolin 5-O-glucoside, apigenin and apigenin 7-O-glucuronide during t-BHP-induced oxidative stress in HepG2 cells. Materials and methodsHepatoprotective potential of the MeOH extracts and flavonoids derived from Korean milk thistle against t-BHP-induced oxidative stress in HepG2 cells were evaluated following MTT method. Incubating HepG2 cells with t-BHP markedly decreased the cell viability and increased the intracellular ROS generation accompanied by depleted GSH levels. Protein expression of heme oxygenase (HO-1) and nuclear factor-E2-related factor 2 (Nrf-2) was determined by Western blot. ResultsOur findings revealed that pretreating HepG2 cells with MeOH extracts and bioactive flavonoids significantly attenuated the t-BHP-induced oxidative damage, followed by increased cell viability in a dose-dependent manner. The results illustrate that excess ROS generation was reduced and GSH levels increased dose-dependently when HepG2 cells were pretreated with four flavonoids. Moreover, Western blotting analysis demonstrated that protein expressions of Nrf-2 and HO-1 were also up-regulated by flavonoids treatment. ConclusionsThese results clearly demonstrate that the MeOH extracts and flavonoids from Korean milk thistle protected HepG2 cells against oxidative damage triggered by t-BHP principally by modulating ROS generation and restoring depleted GSH levels in addition to the increased Nrf-2/HO-1 signaling cascade. These flavonoids are potential natural antioxidative biomarkers against oxidative stress-induced hepatotoxicity.

Antioxidant properties of Resveratrol on Acetaminophen induced toxicity in Wistar Rat liver and HepG2 Cells

Background: Although acetaminophen (APAP) is considered safe at therapeutic doses, intake of high amounts of this drug can cause liver failure. In the present experiment, we examined the hepatoprotective effects of resveratrol (RES) in HepG2 cells and rat liver. Objectives: This study aimed to evaluate the influence of RES on liver function in rat model of necrosis and HepG2 cells. Materials and Methods: In this study, rats were randomly assigned into 4 groups (7 rats in each group) as follows; group 1: control rats (received normal saline), group 2: hepatotoxic control (control rats that received 640 mg/kg/d APAP), group 3: positive control (received 150 mg/kg N-acetylcysteine), group 4: RES (received 30 mg/kg RES). The animals were treated for 7 days. Afterwards, the levels of liver enzymes, protein carbonyl content, glutathione (GSH) level, and Tumor necrosis factor (TNF-α) level were determined. Results: In the in vitro experiment, APAP-induced HepG2 cells were treated with RES at different concentrations and various factors such as cell viability, liver enzymes, GSH and TNF-α levels were measured. Conclusions: Our results indicated that RES could normalize all these factors in vitro and in vivo (P&lt;0.05). In fact, RES had potential hepatoprotective effect against APAP -induced hepatotoxicity in HepG2 cells and animal models mainly via dual change of oxidative stress and cytokine levels.

Lactobacillus fermentum Postbiotic-induced Autophagy as Potential Approach for Treatment of Acetaminophen Hepatotoxicity.

The aim of this study was to investigate the potential of postbiotics originated from Lactobacillus fermentum BGHV110 strain (HV110) to counteract acetaminophen (APAP)-induced hepatotoxicity in HepG2 cells. This strain was selected according to its autophagy inducing potential, based on previous studies reporting protective role of autophagy in APAP caused cellular damage. Cell viability was assessed using MTT and LDH assays, while autophagy was monitored by qPCR analysis of BECN1, Atg5, p62/SQSTM1, and PINK1 mRNA expression and by Western blot analysis of p62/SQSTM1 and lipidated LC3 accumulation. Our results showed that detrimental effect of APAP on cell viability was suppressed in the presence of HV110 which was linked with increased conversion of LC3 protein and p62/SQSTM1 protein degradation. Additionally, higher p62/SQSTM1 and PINK1 mRNA transcription were noticed in cells co-treated with APAP/HV110, simultaneously. In conclusion, this study suggests that HV110 enhances activation of PINK1-dependent autophagy in HepG2 cells and its eventual co-supplementation with APAP could be potentially used for alleviation of hepatotoxic side effects caused by APAP overdose.

Dereplication-guided isolation of novel hepatoprotective triterpenoid saponins from Celosiae Semen by high-performance liquid chromatography coupled with electrospray ionization tandem quadrupole–time-of-flight mass spectrometry

Although natural products (NPs) from ethnomedical plants have played a vital role in modern drug discovery, separation and purification of bioactive compounds from plant extract is still challenging. In this study, a dereplication strategy using HPLC–QTOF-MS was employed to rapidly discover and highly targeted isolate the novel hepatoprotective triterpenoid saponins from the methanol extract of Celosiae Semen. Firstly, four known saponins, i.e. celosin H, celosin I, celosin J, and pseudoginsenoside RT1 were selected as model compounds, and their fragmentation patterns in ESI-QTOF-MS/MS were characterized. Secondly, an HPLC–QTOF-MS/MS method was applied to chemically screen the saponins of interest, and thereby to guide the subsequent fraction and isolation procedure. Thirdly, the targeted isolation of desired compounds afforded two new triterpenoid saponins namely celosin K (1) and celosin L (2), which were structurally elucidated by combination of extensive NMR spectroscopic and chemical analyses. Finally, the protective effects of compounds 1 and 2 against APAP-induced hepatotoxicity in HepG2 cells were evaluated. These results indicate that the HPLC–QTOF-MS-guided isolation is an efficient methodology for isolating new NPs from medicinal plants through improving selectivity in separation and purification process.

Hepatoprotective and antioxidant effect of ellagitannins and galloyl esters isolated from Melaleuca styphelioides on carbon tetrachloride-induced hepatotoxicity in HepG2 cells

Context In a previous study, the total extract of Melaleuca styphelioides Sm. (Myrtaceae) showed a significant hepatoprotective effect in a CCl4-induced toxicity model in mice. However, the active components responsible for the activity of the extract were not identified.Objective To determine the in vitro hepatoprotective activity of the isolated pure compounds from M. styphelioides leaves using the CCl4-challenged HepG2 cell model.Materials and methods The hepatoprotective activity of the compounds (at concentrations of 100, 50 and 25 μm), the total extract and silymarin (Sil) (100, 50 and 25 μg/ml) was determined by measuring the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) after pretreatment with the tested samples for one hour. Glutathione (GSH) and superoxide dismutase activity (SOD) were estimated to determine the mechanisms of the hepatoprotective activity.Results Some compounds showed marked hepatoprotection, including tellimagrandin I, which produced 42, 36 and 31% decrease in ALT and 47, 43 and 37% decrease in AST, at the tested concentrations, respectively, pedunculagin (32, 32 and 30% decrease for ALT and 48, 48 and 45% for AST), tellimagrandin II (38, 32 and 26% decrease for ALT and 45, 40 and 34% for AST) and pentagalloyl glucose (30, 28 and 26% decrease for ALT and 45, 38 and 36% for AST). Tellimagrandin I and II showed the highest increase in GSH (113, 105 and 81% and 110, 103 and 79%, respectively), which was comparable to Sil. Pedunculagin produced the highest increase in SOD (497, 350 and 258%).Conclusion This study highlights promising natural hepatoprotective candidates derived from M. styphelioides.

LC-MS untargeted metabolomic analysis of drug-induced hepatotoxicity in HepG2 cells.

Hepatotoxicity is the number one cause for agencies not approving and withdrawing drugs for the market. Drug-induced human hepatotoxicity frequently goes undetected in preclinical safety evaluations using animal models. Human-derived in vitro models represent a common alternative to in vivo tests to detect toxic effects during preclinical testing. Most current in vitro toxicity assays rely on the measurement of nonspecific or low sensitive endpoints, which result in poor concordance with human liver toxicity. Therefore, making more accurate predictions of the potential hepatotoxicity of new drugs remains a challenge. Metabolomics, whose aim is to globally assess all the metabolites present in a biological sample, may represent an alternative in the search for sensitive sublethal markers of drug-induced hepatotoxicity. To this end, a comprehensive LC-MS-based untargeted metabolite profiling analysis of HepG2 cells, exposed to a set of well-described model hepatotoxins and innocuous compounds, was performed. It allowed to determine meaningful metabolic changes triggered by a toxic insult and gave a first estimation of the main toxicity-related pathways. Based on these metabolic patterns, a partial least squares-discriminant analysis model, able to discriminate between nontoxic and hepatotoxic compounds, was constructed. The approach described herein may provide an alternative for animal testing in preclinical stages of drug development and a controlled experimental approach to gain a better understanding of the underlying causes of hepatotoxicity.

Protective effects of germinated and fermented soybean extract against tert-butyl hydroperoxide-induced hepatotoxicity in HepG2 cells and in rats

The aim of the current study is to investigate the antioxidant and hepatoprotective effects of germinated and fermented soybean extract (GFSE) on tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in HepG2 cells and in the rat liver. High performance liquid chromatography (HPLC) analysis showed that genistin (3.40 ± 0.14 μg mg(-1)) was the most abundant isoflavone in the GFSE. Coumestrol (1.00 ± 0.04 μg mg(-1)), daidzin (0.78 ± 0.14 μg mg(-1)), genistein (0.68 ± 0.05 μg mg(-1)), glycitin (0.54 ± 0.02 μg mg(-1)), glycitein (0.41 ± 0.02 μg mg(-1)), and daidzein (0.02 ± 0.0 g mg(-1)) are also contained in decreasing order of content. GFSE significantly inhibited t-BHP-induced reactive oxygen species (ROS) production in HepG2 cells. This GFSE-induced ROS reduction was associated with the down-regulation of nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), a pro-oxidant enzyme, and the up-regulation of the mRNA levels of antioxidant enzymes, including catalase, superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (Gpx) in the rat liver. In addition, increased levels of antioxidant enzyme mRNAs correlated with the enhanced enzymatic activities of SOD, catalase, and glutathione-S-transferase (GST). The antioxidant effect of GFSE was supported by the reduction in the levels of malondialdehyde (MDA), a hydroperoxide, and the serum levels of lactate dehydrogenase (LDH), a biomarker of cell damage, were also lowered by GFSE. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which are clinical biomarkers of liver function, were shown to be improved with GFSE administration. The effects of GFSE were attributable to an improvement in liver tissue morphology. Taken together, GFSE protected the liver from t-BHP-induced oxidative stress by regulating ROS-related enzymes. Our results suggest that GFSE might be a hepatoprotective source against oxidative stress.

Phytoextract of Indian mustard seeds acts by suppressing the generation of ROS against acetaminophen-induced hepatotoxicity in HepG2 cells

Context: Indian mustard [Brassica juncea (L.) Czern. & Coss. (Brassicaceae)] is reported to possess diverse pharmacological properties. However, limited information is available concerning its hepatoprotective activity and mechanism of action.Objective: To study the protective mechanism of mustard seed extract against acetaminophen (APAP) toxicity in a hepatocellular carcinoma (HepG2) cell line.Materials and methods: Hepatotoxicity models were established using APAP (2.5–22.5 mM) based on the cytotoxicity profile. An antioxidant-rich fraction from mustard seeds was extracted and evaluated for its hepatoprotective potential. The mechanism of action was elucidated using various in vitro antioxidant assays, the detection of intracellular generation of reactive oxygen species (ROS), and cell cycle analysis. The phytoconstituents isolated via HPLC-DAD were also evaluated for hepatoprotective activity.Results: Hydromethanolic seed extract exhibited hepatoprotective activity in post- and pre-treatment models of 20 mM APAP toxicity and restored the elevated levels of liver indices to normal values (p < 0.05). Post-treatment suppressed the generation of ROS by 58.37% and pre-treatment effectively prevented the generation of ROS by 90.5%. The mechanism of ROS suppression was further supported by antioxidant activity (IC50) data from DPPH (103.37 ± 4.2 µg AAE/mg), FRAP (83.26 ± 1.1 µg AAE/mg), ORAC (1115 µM GAE/ml), ABTS (83.05 µg GAE/ml), and superoxide (345.22 ± 5.15 µg AAE/mg) scavenging assays and by the restoration of cell cycle alterations. HPLC-DAD analysis revealed the presence quercetin, vitamin E, and catechin, which exhibited hepatoprotective activity.Discussion and conclusions: A phytoextract of mustard seeds acts by suppressing the generation of ROS in response to APAP toxicity.

High-content screening of drug-induced mitochondrial impairment in hepatic cells: effects of statins.

A frequent mechanism for drug-induced liver injury (DILI) is mitochondrial impairment, and early evaluation of new drugs for their potential to cause mitochondrial dysfunction is becoming an important task for drug development. To this end, we designed a high-content screening assay to study mitochondrial-induced hepatotoxicity in HepG2 cells in detail. Simultaneous assessment of mitochondrial mass and cell viability in cells exposed for 24h to compounds provides preliminary information on the mitochondrial- or nonmitochondrial-related hepatotoxic potential of compounds. To fully address the mechanisms implicated in mitochondrial impairment, prelethal changes in mitochondrial superoxide production, mitochondrial membrane potential, mitochondrial permeability transition, intracellular calcium concentration and apoptotic cell death were studied in cells incubated for 1h with compounds. The assay correctly classified a set of well-known mitochondrial toxicants and negative controls and revealed high sensitivity for the detection of mitochondrial DILI and the establishment of different mitochondrial toxicity risks (low to high). This procedure was used for analysing the potential mitochondrial impairment of six statins to determine their clinical risk. All the tested statins produced mitochondrial impairment, although they showed different levels of toxicity (low-medium toxicity risk). The results suggest that this cell-based assay is a promising in vitro approach to predict the potential of drug candidates to induce mitochondrial-associated hepatotoxicity.

Hepatoprotective effects of fermented field water-dropwort (Oenanthe javanica) extract and its major constituents

Dropwort (Oenanthe javanica) has been used for many years for the treatment of inflammatory conditions, including hepatitis. We investigated the protective effects of fermented field water-dropwort extract (FDE) on tert-butyl hydroperoxide (t-BHP)-induced hepatotoxicity in HepG2 cells and carbon tetrachloride (CCl4)-induced liver damage in rats. Pretreatment with FDE prior to the t-BHP treatment of HepG2 cells inhibited cell death and lactate dehydrogenase (LDH) leakage in a dose-dependent manner. In addition FDE significantly prevented the increase of hepatic enzyme markers (ALT, AST) in vivo. Moreover, FDE administration for 7days significantly affected CYP2E1, CYP4A2, and PPARγ gene expressions. CYP2E1 and CYP4A2 gene expression in the liver, increased 2 and 22-fold by CCl4 administration, respectively, was attenuated to normal levels by pretreatment with FDE. PPARγ gene expression, completely blocked by CCl4 treatment, was increased by FDE pretreatment compared to normal control group. Histopathological examination of the livers also revealed that FDE reduced the incidence of liver lesions. Caffeic acid and chlorogenic acid were identified as major constituents of FDE. These results demonstrate the protective effects of FDE against hepatocytotoxicity induced by CCl4 and t-BHP in rats and HepG2 cells, thus indicating the potential of FDE as a therapeutic for acute liver diseases.

MicroRNA-561 Promotes Acetaminophen-Induced Hepatotoxicity in HepG2 Cells and Primary Human Hepatocytes through Downregulation of the Nuclear Receptor Corepressor Dosage-Sensitive Sex-Reversal Adrenal Hypoplasia Congenital Critical Region on the X Chromosome, Gene 1 (DAX-1)

One of the major mechanisms involved in acetaminophen (APAP)-induced hepatotoxicity is hepatocyte nuclear factor 4α (HNF4α)-mediated activation of pregnane X receptor (PXR) and constitutive androstane receptor (CAR). In the present study, we investigated the role of miR-561 and its target gene DAX-1 encoding a corepressor of HNF4α in the process of APAP-induced hepatotoxicity. We used both human hepatocellular liver carcinoma cell line (HepG2) cells and primary human hepatocytes in this study and monitored the levels of reactive oxygen species, lactate dehydrogenase, and glutathione. Our bioinformatics study suggests an association between miR-561 and DAX-1, but not HNF4α. Treatment of HepG2 cells with APAP significantly reduced the expression of DAX-1 in a concentration-dependent manner. miR-561 was induced by APAP treatment in HepG2 cells. Transfection of HepG2 cells with an miR-561 mimic exacerbated APAP-induced hepatotoxicity. HNF4α is physically associated with DAX-1 in HepG2 cells. A decreased protein level of DAX-1 by APAP treatment was also enhanced by miR-561 mimic transfection in HepG2 cells and primary human hepatocytes. The basal and APAP-induced expression of PXR and CAR was enhanced by miR-561 mimic transfection; however, transfection of HepG2 cells or primary human hepatocytes with a miR-561 inhibitor or DAX-1 small interfering RNA reversed these effects. Additionally, the chromatin immunoprecipitation assay revealed that recruitment of DAX-1 onto the PXR promoter was inversely correlated with the recruitment of peroxisome proliferator-activated receptor-α coactivator-1α and HNF4α on APAP treatment. These results indicate that miR-561 worsens APAP-induced hepatotoxicity via inhibition of DAX-1 and consequent transactivation of nuclear receptors.

Antioxidative and cytoprotective effects of andrographolide against CCl4-induced hepatotoxicity in HepG2 cells

This article describes antioxidative and cytoprotective property of andrographolide, a major active component of the plant Andrographis paniculata (A. paniculata). High yields (2.7%) of andrographolide was isolated from the aerial parts of this plant via silica column chromatography. The purity of the compound was determined by high-performance thin-layer chromatography (HPTLC) and reversed phase high-performance liquid chromatography (HPLC) analysis. The structure was elucidated using techniques such as UV-visible spectrophotometry, elemental analysis, Fourier transform infrared (FT-IR), (1)H nuclear magnetic resonance ((1)H NMR), (13)C nuclear magnetic resonance ((13)C NMR) and mass spectral analysis and the data obtained were comparable with reported results. It was observed that andrographolide exhibited significant antioxidative property (IC50 = 3.2 µg/ml) by its ability to scavenge a stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) as compared to known antioxidants like ascorbic acid, butylated hydroxy toluene (BHT) and the plant extract. The cytoprotective role of andrographolide against carbon tetrachloride (CCl4) toxicity in human hepatoma HepG2 cell line was assessed using trypan blue exclusion test, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, by estimation of various leakage enzymes and by measuring the glutathione levels. The recovery obtained for andrographolide treatment in the presence of CCl4 was two-fold compared to A. paniculata extract for all other related biochemical parameters investigated. The results of the study indicate that andrographolide is a potent inhibitor of CCl4-mediated lipid peroxidation.

Infliximab Exerts No Direct Hepatotoxic Effect on HepG2 Cells In Vitro

BackgroundInfliximab-induced hepatotoxicity is reported in several case studies involving patients with inflammatory bowel disease (IBD) and a direct hepatotoxic effect has been proposed.ObjectiveThe aim of this study was to determine the direct in vitro toxicity of infliximab. As a proof of principle the in vitro toxicity of thiopurines and methotrexate was also determined.MethodsCell survival curves and the half maximal inhibitory concentrations (IC50) were obtained after 24, 48 and 72 h of incubation in HepG2 cells with the IBD drugs azathioprine, 6-mercaptopurine, 6-thioguanine, methotrexate or infliximab by using the WST-1 cytotoxicity assay.ResultsNo in vitro hepatotoxicity in HepG2 cells was seen with infliximab, while concentration-dependent cytotoxicity was observed when HepG2 cells were incubated with increasing concentrations of azathioprine, 6-mercaptopurine and 6-thioguanine.ConclusionInfliximab alone or given in combination with azathioprine showed no direct hepatotoxic effect in vitro, indicating that the postulated direct hepatotoxicity of infliximab is unlikely.

Neolignans and Sesquiterpenes from Cell Cultures ofStellera chamaejasme

Two new neolignans (1, 2) and six sesquiterpenes (3- 8) were isolated from the cell cultures of Stellera chamaejasme. Their structures and absolute configurations were elucidated by extensive spectroscopic and computational methods. Compound 4 exhibited significant protective effects against CCl (4)-induced hepatotoxicity in HepG2 cells, reducing aspartate aminotransferase release by 29.49 % at 10 µM. These compounds have not been isolated from plant material, which implies that in vitro plant cell cultures may offer alternative and effective sources of bioactive natural compounds.

Protective effects of protein hydrolysate from marine microalgae Navicula incerta on ethanol-induced toxicity in HepG2/CYP2E1 cells

Ethanol is independently known to cause tissue damage through various mechanisms. This study was designed to evaluate the protective effect of marine microalgae, Navicula incerta protein enzymatic hydrolysates (NEHs) against ethanol-induced hepatotoxicity in HepG2 cells transfected with human CYP2E1. Induction of CYP2E1 by ethanol is one of the central pathways by which ethanol generates a state of oxidative stress in hepatocytes. When the alcohol-induced cells were treated with NEHs at various concentrations, there was a dose-dependent decrease of gamma-glutamyl transpeptidase (GGT) activity in the culture media and loss of cell viability. Among the NEHs constituents the hydrolysates which were obtained by papain (P-NEH), pronase-E (PR-NEH) and α-chymotrypsin (A-NEH) activity attenuated the ethanol cytotoxicity effectively, respectively. The activity appeared to be a GGT inhibitor. Therefore, the cytoprotective effects at alcohol-induced HepG2/CYP2E1 cells could be attributed to the inhibition of GGT activity by NEHs. This study suggests that NEHs have enough potential to be considered as highly active compounds against ethanol toxicity which leads NEHs to be significant nutraceuticals.

Pathophysiological Relevance of Proteomics Investigations of Drug-Induced Hepatotoxicity in HepG2 Cells

Pathophysiological Relevance of Proteomics Investigations of Drug-Induced Hepatotoxicity in HepG2 Cells