Oxidative Stress In Hepatocytes Research Articles

Differentiated modulation of signaling molecules AMPK and SIRT1 in experimentally drug-induced hepatocyte injury.

Currently available medicines have little to offer in terms of supporting the regeneration of injured hepatic cells. Previous experimental studies have shown that resveratrol and metformin, less specific activators of AMP-activated protein kinase (AMPK) and sirtuin 1 (SIRT1), can effectively attenuate acute liver injury. The aim of this experimental study was to elucidate whether modulation of AMPK and SIRT1 activity can modify drug/paracetamol (APAP)-induced hepatocyte damage in vitro. Primary rat hepatocytes were pretreated with mutual combinations of specific synthetic activators and inhibitors of SIRT1 and AMPK and followed by a toxic dose of APAP. At the end of cultivation, medium samples were collected for biochemical analysis of alanine-aminotransferase and nitrite levels. Hepatocyte viability, thiobarbituric reactive substances, SIRT1 and AMPK activity and protein expression were also assessed. The harmful effect of APAP was associated with decreased AMPK and SIRT1 activity and protein expression alongside enhanced oxidative stress in hepatocytes. The addition of AMPK activator (AICAR) or SIRT1 activator (CAY10591) significantly attenuated the deleterious effects of AMPK inhibitor (Compound C) on the hepatotoxicity of APAP. Furthermore, CAY10591 but not AICAR markedly decreased the deleterious effect of APAP in combination with SIRT1 inhibitor (EX-527). Our findings demonstrate that decreased AMPK activity is associated with the hepatotoxic effect of APAP which can be significantly attenuated by the administration of a SIRT1 activator. These findings suggest that differentiated modulation of AMPK and SIRT1 activity could therefore provide an interesting and novel therapeutic opportunity in the future to combat hepatocyte injury.

Incretin-induced changes in the transcriptome of skeletal muscles of fa/fa Zucker rat (ZFR) with obesity, without diabetes

Glucagon-like peptide-1 receptor agonists (GLP-1ra) are increasingly used in treating type 2 diabetes and obesity. Exendin-4 (Ex-4), a long acting GLP-1ra, was previously reported to decrease oxidative stress in hepatocytes, adipocytes and skeletal muscle cells in obese nondiabetic fa/fa Zucker rats (ZFR), thereby improving insulin resistance. We aimed first to identify Ex-4-induced changes in the transcriptome of skeletal muscle cells in ZFR. Ontology analysis of differentially expressed genes (DEGs) in ZFR versus lean animals (LR) showed that the extracellular matrix (ECM) is the first most affected cellular compartment, followed by myofibrils and endoplasmic reticulum (ER). Interestingly, among 15 genes regulated in ZFR versus LR, 14 of them were inversely regulated by Ex-4, as further confirmed by RT-qPCR. Picro-Sirius red histological staining showed that decreased ECM fiber area in ZFR is partially restored by Ex-4. Ontology analysis of the myofibril compartment revealed that decreased muscle contractile function in ZFR is partially restored by Ex-4, as confirmed by Phalloidin histological staining that showed a partial restoration by Ex-4 of altered contractile apparatus in ZFR. Ontology analysis of ER DEGs in ZFR versus LR showed that some of them are related to the AMP-activated protein kinase (AMPK) signaling pathway. Phosphorylated AMPK levels were strongly increased in Ex-4-treated ZFR. Altogether, our results suggest that GLP-1ra strongly restructure ECM and reinforce contractile capabilities in ZFR, while optimizing the cellular metabolism through AMPK.

From the Editor’s Desk...

From the Editor’s Desk...

SSTEAP4 regulates cellular homeostasis and improves high-fat-diet-caused oxidative stress in hepatocytes

AimNonalcoholic fatty liver disease (NAFLD) has become a global epidemic, but its pathogenesis is unclear. STEAP4, a member of six transmembrane protein family, integrates inflammatory and metabolic responses. Our present aim is to explore the roles of STEAP4 in maintaining cellular homeostasis and improving high-fat-diet (HFD)-caused oxidative stress in hepatocytes. Main methodsNAFLD model was established by HFD-feeding mice. The effects of over-nutrition on liver were detected by serum biochemical analysis and bulk RNA-seq. The levels of gene expression were measured by QPCR and Western Blot. Immunofluorescent staining was applied to determine the localization of STEAP4. AMPK agonist was employed to investigate the link between STEAP4 and AMPK pathway. Key findingsSus scrofa STEAP4 (sSTEAP4) relieved oxidative stress and rescued the viability of hepatocytes. sSTEAP4 increased AKT phosphorylation and SOD2 level in hepatocytes, whether or not treated with H2O2, suggesting sSTEAP4 has regulatory effects on insulin signaling and antioxidant pathways. However, sSTEAP4 inhibited AMPK phosphorylation and Beclin1/LC3 expression under H2O2-deficiency situation, but the results were conversed with H2O2 stimulation. The cellular ER stress was aggravated with the increased energy during oxidative stress, indicating that sSTEAP4 might regulate the energetic communication between ER and mitochondria by intervening mitochondrial energy production. In addition, sSTEAP4 was demonstrated to localize in the membranes of plasma and ER in HepG2 hepatocytes. SignificanceOur results reveal that sSTEAP4 based on the needs of cell itself to improve hepatic oxidative stress and HFD-caused NAFLD, which might provide a new therapeutic scheme for NAFLD.

Dietary Selenium Alleviated Mouse Liver Oxidative Stress and NAFLD Induced by Obesity by Regulating the KEAP1/NRF2 Pathway.

Nonalcoholic fatty liver disease (NAFLD) occurs when excess fat is stored in the liver and it is strongly linked with metabolic syndrome and oxidative stress. Selenium (Se) is an essential micronutrient in animals, which has a variety of biological functions, including antioxidant and anti-inflammatory. However, the exact effect of dietary selenium on NAFLD and the underlying molecular mechanism are not yet clear. Herein, we fed a high-fat diet (HFD) to C57BL/6 mice to construct an in vivo NAFLD model, treated AML-12 cells with palmitic acid (PA) to construct an in vitro NAFLD model, and AML-12 cells were stimulated with H2O2 to induce hepatocyte oxidative stress and then treated with adequate selenium. We observed that adequate selenium significantly improved the hepatic injury and insulin resistance in HFD mice, and decreased the fat accumulation and the expression of lipogenic genes in PA-induced AML-12 cells. Meanwhile, selenium significantly inhibited the production of reactive oxygen species (ROS), inhibited apoptosis, and restored mitochondrial number and membrane potential in PA- induced AML-12 cells. In addition, selenium can promote selenoproteinP1 (SEPP1) synthesis to regulate the Kelch-like ECH-associated protein 1 (KEAP1)/NF-E2-related factor 2 (NRF2) pathway, so as to defend against hepatocyte oxidative stress. These findings suggest that dietary selenium supplementation can effectively resist hepatic injury and insulin resistance during NAFLD development, and regulate the KEAP1/NRF2 pathway to resist oxidative stress by promoting SEPP1 synthesis.

Effect of electroacupuncture on hepatocyte autophagy and oxidative stress in SAMP8 mice by regulating AMPK/mTOR/ULK1 signaling pathway

To observe the effect of electroacupuncture (EA) on physical strength and expression levels of hepatic AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), unc-51 like autophagy activating kinase 1 (ULK1) proteins and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNAs in aging (senescence accelerated mouse/prone 8, SAMP8)mice, so as to exp lore its mechanism underlying delaying aging by activating AMPK/mTOR/ULK1 signaling pathway. Twenty-four male SAMP8 mice were randomly divided into model group, rapamycin (autophagy inducer) group, EA group and EA+autophagy inhibitor (EA+inhibitor) group, with 6 mice in each group, and 6 homologous anti-rapid aging male (SAMR1) mice in the same age were used as the control group. Mice of the rapamycin group received intraperitoneal injection of rapamycin solution (2 mg·kg-1·d-1). EA (2 Hz, 1 mA) was applied to bilateral "Taichong"(LR3)and "Shenshu"(BL23) for 15 min each time. Mice of the EA+inhibitor group received intraperitoneal injection of mTOR inhibitor 3-methyladenine (1.5 mg·kg-1·d-1) before the EA intervention each time. The above-mentioned interventions were conducted 6 times a week for 2 consecutive weeks. Physical conditions of mice were assessed by exhaustive swimming tests. Histopathological changes of the liver were observed by H.E. staining. Western blot was used to detect the expression of AMPK, phosphorylated AMPK (p-AMPK), mTOR, phosphorylated mTOR (p-mTOR), ULK1 and phosphorylated ULK1 (p-ULk1) in the liver tissues. The expression levels of Atg5, Atg7, Atg13, Beclin1 and ULK1 (cellular autophagy-related genes) mRNAs in the liver were detected by quantitative real-time PCR. The immunoactivity (IA) of heme oxygenase 1 (HO-1) in the liver was detected by immunohistochemistry, and the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) of the liver were measured by hydroxylamine method for assessing the level of oxidative stress. Compared with the control group, the duration of exhaustive swimming, the expression levels of AMPK, p-AMPK, ULK1 and p-ULK1 proteins, and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNA, HO-1 IA and SOD activity were considerably down-regulated (P<0.01), while the expression levels of mTOR and p-mTOR and MDA content were significantly up-regulated (P<0.01) in the model group. In comparison with the model group, the duration of the exhausted swimming, the expression levels of AMPK, p-AMPK, ULK1 and p-ULK1 proteins, and Atg5, Atg7, Atg13, Beclin1 and ULK1 mRNAs, HO-1 IA and SOD activity were significantly up-regulated (P<0.01, P<0.05), whereas the expression levels of mTOR and p-mTOR proteins and MDA content were notably down-regulated (P<0.01, P<0.05) in the rapamycin, EA and EA+inhibitor groups. The improvement of the abovementioned indexes of EA+inhibitor group was not as good as rapamycin and EA groups (P<0.01), suggesting an elimination of the therapeutic effects after administration of 3-methyladenine. No significant differences were found between the rapamycin and EA groups in the abovementioned indexes (P>0.05) except p-mTOR and mTOR which were higher in the EA group (P<0.01). H.E. staining showed ambiguous boundary of the liver lobule, disordered arrangement of hepatocytes with a large amount of fat vacuoles at different size and deviation of nucleus, and lysis of some hepatocytes. These situations were relatively milder in the rapamycin and EA groups. EA may enhance physical strength and promote cellular autophagy in the liver of aging mice by regulating AMPK/mTOR/ULK1 signaling, thereby inhibiting excessive oxidative stress, and delaying aging process to some extent.

Oleanolic acid-loaded nanoparticles attenuate activation of hepatic stellate cells via suppressing TGF-β1 and oxidative stress in PM2.5-exposed hepatocytes

Liver fibrosis has the potential to progress into liver cirrhosis, liver failure, and even death. Hepatic stellate cells (HSCs) activation play a central role in liver fibrosis, and persistently damaged hepatocytes secrete soluble factors that activate transdifferentiation of HSCs into myofibroblasts. Our previous studies indicated that fine particulate matter (PM2.5) can activate HSCs by stimulating hepatocytes to secrete TGF-β1. However, whether PM2.5 activates HSCs by regulating oxidative stress in hepatocytes remains uncertain. Oleanolic acid (OA) has been widely used in the clinic for hepatoprotection in Chinese medicine. In the present study, OA-loaded nanoparticles (OA-NP) with high solubility were used to attenuate the activation of HSCs induced by PM2.5-treated hepatocytes, and further studies were performed to explore the mechanism in which OA-NP plays a vital part. Our results showed that consistently PM2.5 treatment induced oxidative stress in hepatocytes. Moreover, the activation of HSCs induced by PM2.5-treated hepatocytes was reversed by antioxidant N-acetylcysteine treatment. Hence, PM2.5 may participate in the activation of HSCs by regulating oxidative stress in hepatocytes. Using a co-cultivation system, our results proved pretreatment with OA-NP significantly attenuates the activation of HSCs induced by PM2.5-exposed hepatocytes. In addition, the TGF-β1 expression and oxidative stress in hepatocytes with PM2.5 treated were reduced by the incubation with OA-NP. These observations demonstrated that OA-NP protects against the activation of HSCs by decreasing the TGF-β1 level and oxidative stress in PM2.5-exposed hepatocytes.

Curcumin mitigates aflatoxin B1-induced liver injury via regulating the NLRP3 inflammasome and Nrf2 signaling pathway

Aflatoxins are produced as secondary metabolites by the toxigenic Aspergillus fungi. Among the aflatoxins, aflatoxin B1 (AFB1) is a common contaminant of global concern in human and animal food products. Prolonged exposure to AFB1 may provoke hepatocyte pyroptosis and oxidative stress, which leads to liver damage. Dietary polyphenols could protect the liver from a wide range of toxins. Curcumin, a polyphenolic substance derived from turmeric, is rich in pharmacological activity. The aim of this study was to systematically investigate the protective effects of curcumin against AFB1-induced liver injury in mice and to explore the possible molecular mechanisms. BALB/c mice received oral gavage of AFB1 (0.75 mg/kg) and curcumin (100 or 200 mg/kg) for 30 days. Our data demonstrated that curcumin attenuated AFB1-induced weight loss in mice and rescued liver injury by mitigating the alterations in pathology and liver function with AFB1 exposure. Curcumin reduced the accumulation of AFB1-DNA adducts in the liver and alleviated hepatotoxicity by inhibiting AFB1-induced oxidative stress and potentiating glutathione S-transferase (GST)-mediated phase II detoxification. In addition, curcumin significantly reduced the characteristic indices of AFB1-induced pyroptosis, such as the expression of mRNAs for genes related to NOD-like receptor protein 3 (NLRP3) inflammasome assembly and activation, the expression of key proteins (NLRP3, Caspase-1 and GSDMD). The release of interleukin-1β (IL-1β) and interleukin-18 (IL-18) in the serum detected by ELISA was also significantly decreased. Notably, administration of curcumin upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its related downstream antioxidant molecules (SOD, CAT, HO-1, NQO1) and phase II detoxification enzyme-related molecules (GST, GSH, GSS, GCLC, GCLM) in the presence of AFB1 exposure. To summarize, our results indicated that curcumin could modulate the NLRP3 inflammasome and Nrf2 signaling pathways to attenuate AFB1-induced liver pyroptotic damage and oxidative stress.

Arsenic trioxide-induced autophagy affected the antioxidant capacity and apoptosis rate of chicken hepatocytes

Arsenic has recently received widespread attention due to its high toxicological effects on multiple animals; however, the mechanism underlying this toxicity is unclear. We investigated the damaging effects of arsenic trioxide (ATO) on hepatocytes and the effects of regulating autophagy on the hepatocyte damage induced by ATO exposure. First, we investigated the effects of ATO exposure (0, 0.6, 1.2, 2.4, and 4.8 μM) on the biochemical function and autophagy of chicken hepatocytes. The findings showed that as the concentration of ATO increased, the lactate dehydrogenase (LDH) concentration increased, more autophagosomes were observed via transmission electron microscopy (TEM), and the gene and protein expression levels of P62, LC3Ⅱ, and Beclin1 increased. Adding N-acetyl-l-cystine (NAC, 1 mM) attenuated autophagy and the hepatocyte damage induced by ATO. Then, we used rapamycin (Rapa) and 3-methylpurine (3-MA) to regulate the autophagy induced by exposure to 4.8 μM ATO and observed changes in the antioxidant capacity and apoptosis rate of chicken hepatocytes. Induction of autophagy reduced ATO-induced hepatocyte apoptosis but caused no significant effect on oxidative stress in chicken hepatocytes. Inhibition of autophagy exacerbated ATO-induced hepatocyte oxidative stress and apoptosis. These findings demonstrate that autophagy plays an important role in ATO-induced cell damage.

Sinapine Improves LPS-Induced Oxidative Stress in Hepatocytes by Down-Regulating MCJ Protein Expression

Sinapine Improves LPS-Induced Oxidative Stress in Hepatocytes by Down-Regulating MCJ Protein Expression

SSTEAP4 Regulates Cellular Homeostasis and Improves High-Fat-Diet-Caused Oxidative Stress in Hepatocytes

sSTEAP4 Regulates Cellular Homeostasis and Improves High-Fat-Diet-Caused Oxidative Stress in Hepatocytes

Mechanism of action of Jieduhuayu granules for remission of oxidative stress in hepatocytes

Objective: To study and explore the effect and mechanism of action of Jieduhuayu granules on oxidative injury of human liver L02 cells. Methods: Human liver L02 oxidative injury model was established with 0.1 mmol/ L H(2)O(2) intervention for 1 h, and treated with different concentrations of Jieduhuayu (JDHY) solution. Hepatocytes were divided into five groups: normal, H(2)O(2), H(2)O(2) + JDHY (0.5 mg/ml), H(2)O(2) + JDHY (1 mg/ml), and H(2)O(2) + JDHY (1.5 mg/ml). MTT assay was used to detect hepatocytes activity. Transmission electron microscope was used to observe mitochondrial morphology in hepatocytes. Biochemical test was used to detect the levels of superoxide dismutase, lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, malondialdehyde, and reduced glutathione and albumin in hepatocytes. Western blot was used to detect the expression levels of rabbit anti-phosphatidylinositol 3-kinase (PI3K), AKT and mTOR in hepatocytes. One-way analysis of variance was used for comparison between multiple groups, and the LSD method was used for pairwise comparison. Results: Compared with the normal group, the cell proliferation activity (P < 0.05), mitochondrial vacuolization, superoxide dismutase activity, reduced albumin and glutathione content, and PI3K, AKT, and mTOR protein expression levels in the H(2)O(2) group were all significantly reduced (P < 0.05), while the content of malondialdehyde and the activities of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase were significantly increased (P < 0.05). Compared with H(2)O(2) group, the cell proliferation activity (P < 0.05), alterations in morphological remission of mitochondria, superoxide dismutase activity, reduced albumin and glutathione content, and PI3K, AKT and mTOR protein expression levels in the H(2)O(2) + JDHY (1 mg/ml) and H(2)O(2) + JDHY (1.5 mg/ml) group (P < 0.05) were all significantly increased (P < 0.05), while malondialdehyde content and alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities were significantly decreased (P < 0.05). Conclusion: Jieduhuayu granule can effectively improve oxidative stress and mitochondrial injury in hepatocytes, and its effect may be related to the promoting expression of PI3K/AKT/mTOR signaling pathways.

Arbutin Alleviates the Liver Injury of α-Naphthylisothiocyanate-induced Cholestasis Through Farnesoid X Receptor Activation.

Cholestasis is a kind of stressful syndrome along with liver toxicity, which has been demonstrated to be related to fibrosis, cirrhosis, even cholangiocellular or hepatocellular carcinomas. Cholestasis usually caused by the dysregulated metabolism of bile acids that possess high cellular toxicity and synthesized by cholesterol in the liver to undergo enterohepatic circulation. In cholestasis, the accumulation of bile acids in the liver causes biliary and hepatocyte injury, oxidative stress, and inflammation. The farnesoid X receptor (FXR) is regarded as a bile acid–activated receptor that regulates a network of genes involved in bile acid metabolism, providing a new therapeutic target to treat cholestatic diseases. Arbutin is a glycosylated hydroquinone isolated from medicinal plants in the genus Arctostaphylos, which has a variety of potentially pharmacological properties, such as anti-inflammatory, antihyperlipidemic, antiviral, antihyperglycemic, and antioxidant activity. However, the mechanistic contributions of arbutin to alleviate liver injury of cholestasis, especially its role on bile acid homeostasis via nuclear receptors, have not been fully elucidated. In this study, we demonstrate that arbutin has a protective effect on α-naphthylisothiocyanate–induced cholestasis via upregulation of the levels of FXR and downstream enzymes associated with bile acid homeostasis such as Bsep, Ntcp, and Sult2a1, as well as Ugt1a1. Furthermore, the regulation of these functional proteins related to bile acid homeostasis by arbutin could be alleviated by FXR silencing in L-02 cells. In conclusion, a protective effect could be supported by arbutin to alleviate ANIT-induced cholestatic liver toxicity, which was partly through the FXR pathway, suggesting arbutin may be a potential chemical molecule for the cholestatic disease.

Albicanol inhibits the toxicity of profenofos to grass carp hepatocytes cells through the ROS/PTEN/PI3K/AKT axis

Profenofos (PFF) as an environmental pollutant seriously harms the health of aquatic animals, and even endangers human safety through the food chain. Albicanol, a sesquiterpenoid extraction from the Dryopteris fragrans, has previously been shown to effectively exhibit anti-aging, anti-oxidant, and antagonize the toxicity of heavy metals. However, the mechanism of hepatocyte toxicity caused by PFF and the role that Albicanol plays in this process are still unclear. In this study, a PFF poisoning model was established by treating grass carp hepatocytes cells with PFF (150 μM) for 24 h The results of AO/EB staining, Tunel staining and flow cytometry showed that the proportion of apoptotic liver cells increased significantly after exposure. The results of ROS staining show that compared with the control group, ROS levels and PTEN/PI3K/AKT-related gene expression were up-regulated after PFF exposure. RT-qPCR and Western blotting results showed that the expression of PTEN/PI3K/AKT related genes was up-regulated. These results indicate that PFF can induce oxidative stress in hepatocytes and inhibit the phosphorylation of AKT. We further found that the expressions of Bax, CytC, Caspase-3, Caspase-9, Caspase-8 and TNFR1 after PFF exposure were significantly higher than those of the control group, and Bcl-2/Bax was significantly lower than that of the control group. These results indicate that PFF can induce oxidative stress in hepatocytes and inhibit the phosphorylation of AKT and activate mitochondrial apoptosis. Using Albicanol (5 × 10−5 μg mL−1) can significantly reduce the above-mentioned effects of PFF exposure on grass carp hepatocytes cells. In summary, Albicanol inhibits PFF-induced apoptosis by regulating the ROS/PTEN/PI3K/AKT pathway.

C24:0 avoids cold exposure-induced oxidative stress and fatty acid β-oxidation damage

SummaryLow temperatures can cause severe growth inhibition and mortality in fish. Previous studies about the cold resistance of fish mainly focused on the role of unsaturated fatty acids, rather than saturated fatty acids (SFAs). In this study, the role of very-long-chain SFA synthetized by fatty acyl elongase 1 gene (elovl1) in cold resistance was explored. Both an aggravated liver oxidative stress and a mitochondrial metabolism disorder were observed in elovl1a–/– and elovl1b–/– zebrafish with cold stress. In vitro studies confirmed that high levels of C20:0 and C22:0 obviously increased the hepatocyte oxidative stress and activated the extracellular signal-regulated kinases 1/2 (Erk1/2) pathway to further induce apoptosis and inflammation. We further demonstrated that C24:0 could promote mitochondrial β-oxidation to improve the cold resistance of zebrafish. Overall, our results define a positive role of C24:0 fatty acids synthetized by elovl1 in the cold resistance of fish.

Capillin protects against non-alcoholic steatohepatitis through suppressing NLRP3 inflammasome activation and oxidative stress

Background Non-alcoholic steatohepatitis (NASH) is an extreme form of non-alcoholic fatty liver disease. The present study concentrated on the role of Capillin, a polyacetylene compound isolated from Artemisia capillaris Thunb., in NASH development. Materials and methods Palmitic acid (PA) was treated with FL83B hepatocytes, and high-fat diet was given to mouse to construct the NASH model in vivo. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, flow cytometry, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were carried out to measure the viability and apoptosis of FL83B hepatocytes. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to measure the mRNA expressions of infiltration markers (Cd11c, Ccr2, and Ly6c), fibrosis genes (Tgfβ1, Col1a1, and Timp1), and alpha-smooth muscle actin (α-SMA). Western blot, immunofluorescence, and Enzyme-linked immunosorbent assay (ELISA) were implemented to examine the proteins of Caspase-3, Bcl2, Nrf2, HO-1, NLRP3, ASC, and Caspase-1, the ROS level, and oxidative stress markers (MDA, GSH-ST, SOD, and GSH-Px), and the lipid peroxidation level, respectively. Moreover, HE staining was manipulated to observe the histopathological changes in liver tissue. Results Capillin hampered PA-mediated hepatocytes apoptosis and enhanced cell viability. Furthermore, Capillin suppressed PA-mediated oxidative stress in hepatocytes, promoted Nrf2/HO-1 expression, and repressed NLRP3-ASC-Caspase1 inflammasome. The in vivo studies indicated that Capillin vigorously improves liver fat accumulation, oxidative stress, and liver injury in NASH mice. Mechanistically, Capillin repressed NLRP3-ASC-Caspase1 inflammasome and up-regulated the Nrf2-HO-1 pathway in the liver. Conclusion Capillin ameliorates hepatocyte injury by dampening oxidative stress and repressing NLRP3 inflammasome in NASH mice.

S-ademetionine in the treatment of non-alcoholic fatty liver disease (NAFLD)

The experimental and clinic data supporting S- ademetionin application in NAFLD complex therapy were presented. The therapy corrects an oxidative stress in hepatocytes and transforms the nutrition behavior in patients with excessive body weight when depressive syndrome is developed.

Dihydromyricetin attenuates palmitic acid-induced oxidative stress by promoting autophagy via SIRT3-ATG4B signaling in hepatocytes

BackgroundOxidative stress in hepatocytes was important pathogenesis of nonalcoholic steatohepatitis (NASH). Autophagy was a cellular process that can remove damaged organelles under oxidative stress, and thus presented a potential therapeutic target against NASH. This work aimed to investigate whether autophagy was participated in the protective effects of dihydromyricetin (DHM) on palmitic acid (PA)-induced oxidative stress in hepatocytes and the underlying mechanism.MethodsHepG2 and HHL-5 cell lines were pretreated with DHM (20 μM) for 2 h, followed by PA (0.2 mM) treatment for 16 h. The oxidative stress was assessed by the quantification of intracellular reactive oxygen species (ROS), mitochondrial ROS (mtROS), mitochondrial membrane potential (MMP) and mitochondrial ultrastructural analyses. The protein expressions of SIRT3, LC3I/II, P62 and ATG4B, as well as the acetylation of AGT4B were determined by western blotting using HepG2 and HepG2/ATG4B± cells with heterozygous knockout of ATG4B.ResultsExposure to PA resulted in increased intracellular ROS and mtROS, decreased MMP and aggravated mitochondrial injury in HepG2 cells, which were notably attenuated by DHM treatment. DHM-induced inhibition of oxidative stress was associated with the induction of autophagy, characterized by upregulated ATG4B and LC3 II as well as downregulated P62 levels. Furthermore, the inhibitory effects of DHM on PA-induced autophagy arrest and oxidative stress were eliminated when pretreated with a SIRT3 inhibitor 3-TYP or conducted in HepG2/ATG4B± cells, suggesting that SIRT3 and ATG4B were involved in DHM-induced benefits. Moreover, DHM treatment increased the protein expression of SIRT3 and SIRT3-dependent deacetylation of ATG4B in HepG2 cells.ConclusionOur results demonstrated that DHM attenuated PA-induced oxidative stress in hepatocytes through induction of autophagy, which was mediated through the increased expression of SIRT3 and SIRT3-mediated ATG4B deacetylation following DHM treatment.

THE CHEMOTHERAPEUTIC ROLE OF p-MCA IN AVERTING NDEA INDUCED HEPATIC CARCINOGENESIS IN EXPERIMENTAL WISTAR RATS

OBJECTIVES: Hepatocellular carcinoma (HCC) is the primary liver cancer and second leading cause of cancer related deaths worldwide. The aim of this present study was to evaluate the biochemical, histopathological and chemotherapeutic efcacy of p-methoxycinnamic acid (p-MCA) against N- nitrosodiethylamine (NDEA) in a rat model of hepatocellular carcinoma. MATERIALS AND METHODS: Approximately thirty male wistar rats weighing 150-200 g were designated for this study. The rats were arbitrarily separated into ve groups and each group comprised of six rats. Group 1 served as control; Group 2 rats received p-MCA at the dose of 80 mg/kg b.w. Group 3, 4 and 5 rats were induced HCC using NDEA. 2-acetylaminouorene (AAF) was used as a promotor. Group 4 and 5 rats received p-MCA at the doses of 40 and 80 mg/kg b.w. throughout the 12 week experimental period. At the end of the experimental period, liver tissues from all the rats were collected and liver specic enzymes, lipid peroxidation, markers, xenobiotic metabolizing enzymes, antioxidant status and brotic markers were evaluated.RESULTS: NDEA administration induced hepatocyte damage, oxidative stress, cell proliferation, inammation and brosis. The liver sections from NDEA induced group 3 rats showed loss of lobular architecture, morphological changes in the nuclei and DNA damage. Administration of p-MCA to NDEA treated rats restored the hepatic architecture, enzyme activities, cell proliferation, inammation and brosis.CONCLUSION: We conclude that oral administration of p-MCA for 12 weeks exerts a signicant therapeutic effect against HCC by regulating the concentration of specic hepatic and xenobiotic enzymes, suppressing oxidative stress, inhibiting cell proliferation and reducing the inammatory response.

NFATc4 mediates ethanol-triggered hepatocyte senescence

BackgroundHepatocyte senescence is a core event that mediates the occurrence and development of alcoholic liver disease. Nuclear factor of activated T-cells 4 (NFATc4) is a key driver of nonalcoholic steatohepatitis. However, little was known about the implication of NFATc4 for alcoholic liver disease. This study was aimed to investigate the role of NFATc4 in hepatocyte senescence and further elucidate the underlying mechanism. MethodsReal-time PCR, Western blot, immunofluorescence staining, and enzyme-linked immunosorbent assay were performed to explore the role of NFATc4 in hepatocyte senescence. ResultsNFATc4 was induced in ethanol-incubated hepatocytes. NFATc4 knockdown recovered cell viability and reduced the release of aspartate transaminase, alanine transaminase, and lactic dehydrogenase from ethanol-incubated hepatocytes. NFATc4 knockdown protected mice from alcoholic liver injury and inflammation. NFATc4 knockdown counteracted ethanol-induced hepatocyte senescence, evidenced by decreased senescence-associated β-galactosidase positivity and reduced p16, p21, HMGA1, and γH2AX, which was validated in in vivo studies. Peroxisome proliferator-activated receptor (PPAR)γ was inhibited by NFATc4 in ethanol-treated hepatocytes. PPARγ deficiency abrogated the inhibitory effects of NFATc4 knockdown on hepatocyte senescence, oxidative stress, and hepatic steatosis in mice with alcoholic liver disease. ConclusionsThis work discovered that ethanol enhanced NFATc4 expression, which further triggered hepatocyte senescence via repression of PPARγ.