Evaluation of the intracellular lipid-lowering effect of polyphenols extract from highland barley in HepG2 cells

Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against obesity.In practical application,the research of food combinations is more significant than a specific food component.This study investigated the lipid-lowering effect of highland barley polyphenols via lipase assay in vitro and HepG2 cells induced by oleic acid(OA).Five indexes,triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein-cholesterol(LDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),were used to evaluate the lipidlowering effect of highland barley extract.We also preliminary studied the lipid-lowering mechanism by Realtime fluorescent quantitative polymerase chain reaction(q PCR).The results indicated that highland barley extract contains many components with lipid-lowering effects,such as hyperoside and scoparone.In vitro,the lipase assay showed an 18.4%lipase inhibition rate when the additive contents of highland barley extract were 100μg/m L.The intracellular lipid-lowering effect of highland barley extract was examined using 0.25 mmol/L OA-induced HepG2 cells.The results showed that intracellular TG,LDL-C,and T-CHO content decreased by 34.4%,51.2%,and 18.4%,respectively.ALT and AST decreased by 51.6%and 20.7%compared with the untreated hyperlipidemic HepG2 cells.q PCR results showed that highland barley polyphenols could up-regulation the expression of lipid metabolism-related genes such as PPARγand Fabp4.

Reduction of the oxidative damage to H_(2)O_(2)-induced HepG2 cells via the Nrf2 signalling pathway by plant flavonoids Quercetin and Hyperoside

Hyperoside and quercetin are similar in molecular structures.In this study,the antioxidant regulatory targets of hyperoside and quercetin are mainly in the nuclear factor(erythroid-2-derived)-related factor 2(Nrf2)pathway predicted by network pharmacology.And the antioxidant effect and mechanism of hyperoside and quercetin were measured and compared in H_(2)O_(2)-induced Hep G2 cells and Caenorhabditis elegans.The findings indicated that quercetin was more effective than hyperoside in reducing oxidative damage,which was proved by improved cell viability,decreased reactive oxygen species(ROS)production,decreased cellular apoptosis,and alleviated mitochondrial damage.In addition,quercetin was more efficient than hyperoside in enhancing the expression of Nrf2-associated m RNAs,increasing the activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),and catalase(CAT),and reducing the cellular malondialdehyde(MDA)content.Quercetin was superior to hyperoside in prolonging the lifespan of worms,decreasing the accumulation of lipofuscin,inhibiting ROS production,and increasing the proportion of skn-1 in the nucleus.With the Nrf2 inhibitor ML385,we verified that quercetin and hyperoside primarily protected the cells against oxidative damage via the Nrf2 signalling pathway.Furthermore,molecular docking and dynamics simulations demonstrated that the quercetin-Kelch-like ECH-associated protein 1(Keap1)complex was more stable than the hyperoside-Keap1 complex.The stable structure of the complex might hinder the binding of Nrf2 and Keap1 to release Nrf2 and facilitate its entry into the nucleus to play an antioxidant role.Overall,quercetin had a better antioxidant than hyperoside.

Naringin ameliorates H_(2)O_(2)-induced oxidative damage in cells and prolongs the lifespan of female Drosophila melanogaster via the insulin signaling pathway

Naringin exists in a wide range of Chinese herbal medicine and has proven to possess several pharmacological properties.In this study,PC12,HepG2 cells,and female Drosophila melanogaster were used to investigate the antioxidative and anti-aging effects of naringin and explore the underlying mechanisms.The results showed that naringin inhibited H_(2)O_(2)-induced decline in cell viability and decreased,the content of reactive oxygen species in cells.Meanwhile,naringin prolonged the lifespan of flies,enhanced the abilities of climbing and the resistance to stress,improved the activities of antioxidant enzymes,and decreased malondialdehyde content.Naringin also improved intestinal barrier dysfunction and reduced abnormal proliferation of intestinal stem cells.Moreover,naringin down-regulated the mRNA expressions of inr,chico,pi 3k,and akt-1,and up-regulated the mRNA expressions of dilp2,dilp3,dilp5,and foxo,thereby activating autophagy-related genes and increasing the number of lysosomes.Furthermore,the mutant stocks assays and computer molecular simulation results further indicated that naringin delayed aging by inhibiting the insulin signaling(IIS)pathway and activating the autophagy pathway,which was consistent with the result of network pharmacological predictions.

Protective effect of brain and muscle arnt-like protein-1 against ethanol-induced ferroptosis by activating Nrf2 in mice liver and HepG2 cells

Alcohol abuse has recently become a serious health concern worldwide,and the incidence of alcoholic liver disease(ALD)is rapidly increasing with high morbidity and mortality.Ferroptosis is a newly recognized form of regulated cell death caused by the iron-dependent accumulation of lipid peroxidation.Here we showed that the circadian clock protein brain and muscle arnt-like protein-1(BMAL1)in hepatocytes is both necessary and sufficient to protect against ALD by mitigating ferroptosis.U pon exposure to alcohol(5%Lieber-DeCarli liquid alcohol diet for 10 days before binged alcohol with 5 g/kg body weight in vivo,300 mmol/L for 12 h in vitro,respectively),the content of iron,reactive oxygen species(ROS)and malondialdehyde(MDA)was boosted signifi cantly while glutathione(GSH)was decreased that mainly based on the downregulated protein expression of ferritin heavy chain(FTH),ferroportin(FPN),heme oxygenase1(HO-1)and anti-cystine/glutamate antiporter(SLC7A11),while these changes could be abolished by ferroptosis inhibitor Ferrostatin-1[Fer-1(5 mg/kg body weight for 10 days in vivo,10μmol/L for 2 h in vitro,respectively)].Further study indicated that the alcohol could activate the protein expression of BMAL1 which exerts a protective effect against ferroptosis through promoting nuclear factor erythroid 2-related factor 2(Nrf2)translocation into nuclear and subsequently stimulating its downstream proteins FTH,FPN,glutathione peroxidase 4 activity(GPX4),HO-1,SLC7A11,while knockdown of BMAL1 and Nrf2 by RNA interference further downregulated the expression of these protein and thus promoting ferroptosis in response to alcohol.Collectively,our results unveiled that the protective action of BMAL1 during alcohol challenge depends on its ability to activate Nrf2-ARE antiferroptosis pathway and targeting hepatic BMAL1 to dampen hepatic ferroptosis signaling may have therapeutic potential for ALD.

mRNA transcriptome profiling of human hepatocellular carcinoma cells HepG2 treated with Catharanthus roseus-silver nanoparticles

BACKGROUND The demand for the development of cancer nanomedicine has increased due to its great therapeutic value that can overcome the limitations of conventional cancer therapy.However,the presence of various bioactive compounds in crude plant extracts used for the synthesis of silver nanoparticles(AgNPs)makes its precise mechanisms of action unclear.AIM To assessed the mRNA transcriptome profiling of human HepG2 cells exposed to Catharanthus roseus G.Don(C.roseus)-AgNPs.METHODS The proliferative activity of hepatocellular carcinoma(HepG2)and normal human liver(THLE3)cells treated with C.roseusAgNPs were measured using MTT assay.The RNA samples were extracted and sequenced using BGIseq500 platform.This is followed by data filtering,mapping,gene expression analysis,differentially expression genes analysis,Gene Ontology analysis,and pathway analysis.RESULTS The mean IC 50 values of C.roseusAgNPs on HepG2 was 4.38±1.59μg/mL while on THLE3 cells was 800±1.55μg/mL.Transcriptome profiling revealed an alteration of 296 genes.C.roseusAgNPs induced the expression of stress-associated genes such as MT,HSP and HMOX-1.Cellular signalling pathways were potentially activated through MAPK,TNF and TGF pathways that are responsible for apoptosis and cell cycle arrest.The alteration of ARF6,EHD2,FGFR3,RhoA,EEA1,VPS28,VPS25,and TSG101 indicated the uptake of C.roseus-AgNPs via both clathrin-dependent and clathrinindependent endocytosis.CONCLUSION This study provides new insights into gene expression study of biosynthesised AgNPs on cancer cells.The cytotoxicity effect is mediated by the aberrant gene alteration,and more interestingly the unique selective antiproliferative properties indicate the C.roseusAgNPs as an ideal anticancer candidate.

Anti-diabetic potential of apigenin,luteolin,and baicalein via partially activating PI3K/Akt/GLUT-4 signaling pathways in insulin-resistant HepG2 cells

Dietary flavonoids are abundant in natural plants and possess multiple pharmacological and nutritional activities.In this study,apigenin,luteolin,and baicalein were chosen to evaluate their anti-diabetic effect in high-glucose and dexamethasone induced insulin-resistant(IR)HepG2 cells.All flavonoids improves the glucose consumption and glycogen synthesis abilities in IR-HepG2 cells via activating glucose transporter protein 4(GLUT4)and phosphor-glycogen synthase kinase(GSK-3β).These fl avonoids signifi cantly inhibited the production of reactive oxygen species(ROS)and advanced glycation end-products(AGEs),which were closely related to the suppression of the phosphorylation form of NF-κB and P65.The expression levels of insulin receptor substrate-1(IRS-1),insulin receptor substrate-2(IRS-2)and phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway in IR-HepG2 cells were all partially activated by the fl avonoids,with variable effects.Furthermore,the intracellular metabolic conditions of the fl avonoids were also evaluated.

Ghrelin regulates insulin resistance by targeting insulin-like growth factor-1 receptor via miR-455-5p in hepatic cells

Objective: To explore the mechanism by which ghrelin regulates insulin sensitivity through modulation of miR-455-5p in hepatic cells. Methods: HepG2 cells were treated with or without DAG (1 μM). Glucose consumption, intracellular glycogen content, phosphorylation of PI3K and Akt stimulated by insulin, expression of miR-455-5p, as well as IGF-1R protein level were analyzed. In addition, bioinformatic analysis, dual luciferase reporter assay, miR- 455-5p mimic or inhibitor treatment was conducted to investigate the molecular mechanisms. Results: High glucose treatment upregulated miR-455-5p expression but reduced glucose consumption and glycogen content. DAG reversed the effect of high glucose on glucose metabolism, increased protein level of IGF-1R and phosphorylation of PI3K/Akt stimulated by insulin, as well as downregulated miR-455-5p expression. Bioinformatic analysis indicated IGF-1R was the target of miR-455-5p. Dual luciferase reporter assay, as well as transfection with miR-455-5p mimic/inhibitor confirmed that DAG activated IGF-1R/PI3K/Akt signaling via inhibiting miR-455-5p. Conclusion: DAG improves insulin resistance via miR-455-5p- mediated activation of IGF-1R/PI3K/Akt system, suggesting that suppression of miR-455-5p or activation of DAG may be potential targets for T2DM therapy.

黄蜀葵花总黄酮介导AKT1信号通路拮抗HepG-2细胞脂质沉积研究

目的:探讨黄蜀葵花总黄酮(TFA)对棕榈酸(PA)诱导HepG-2细胞脂质沉积模型的干预效应及机制。方法:体外培养人肝源HepG-2细胞,应用PA处理以构建细胞脂质沉积模型,然后从黄蜀葵花中提取TFA,以TFA或蛋白激酶B(AKT)抑制剂作为干预剂,对PA诱导的细胞脂质沉积模型进行预处理,应用油红O染色、酶联免疫吸附实验和免疫印迹实验(Western blotting)检测细胞脂质代谢、AKT1和脂联素(APN)信号通路蛋白表达水平。结果:与PA模型组比较,TFA或AKT抑制剂干预后,细胞脂质沉积程度(%)、游离脂肪酸(FFAs)和甘油三酯(TG)水平降低,而APN水平升高(P<0.05)。Western blotting实验显示PA模型组AKT1和固醇调节元件结合蛋白1(SREBP-1)表达水平上调而APN和糖原合成酶激酶3β(GSK3β)水平下调(P<0.05)。与PA模型组比较,TFA或AKT抑制剂干预显示AKT1下调而APN水平上调,其下游信号GSK3β表达上调而SREBP-1表达下调(P<0.05)。结论:TFA拮抗PA诱导的HepG-2细胞脂质沉积可能与其介导AKT1抑制及APN信号通路激活有关。

The anti-cancerous mechanism of licochalcone A on human hepatoma cell HepG2 based on the miRNA omics

To explore the function of licochalcone A as an anticancer phytochemical on HepG2 cells and investigate its potential mechanisms,we analyzed the microRNAs(miRNAs)expression profile of HepG2 cells in response to licochalcone A(70μmol/L)in vitro.102 dysregulated miRNAs were detected,and SP1 was expected as the transcription factor that regulates the functions of most screened miRNAs.A sum of 431 targets,the overlap of predicted mRNAs from TargetScan,miRDB,and miRtarbase were detected as the targets for these dysregulated miRNAs.FoxO signaling pathway was the hub pathway for the targets.A protein-protein interaction network was structured on the STRING platform to discover the hub genes.Among them,PIK3R1,CDC42,ESR1,SMAD4,SUMO1,KRAS,AGO1,etc.were screened out.Afterwards,the miRNA-target networks were established to screen key dysregulated miRNAs.Two key miRNAs(hsa-miR-133b and hsa-miR-145-5p)were filtered.Finally,the miRNA-target-transcription factor networks were constructed for these key miRNAs.The networks for these key miRNAs included three and two transcription factors,respectively.These identified miRNAs,transcription factors,targets,and regulatory networks may offer hints to understand the molecular mechanism of licochalcone A as a natural anticarcinogen.

MiR-34a overexpression enhances the inhibitory effect of doxorubicin on HepG2 cells

BACKGROUND Hepatocellular carcinoma(HCC) is the third leading cause of death from malignant tumors worldwide. More than 50% of HCC cases occur in China. The prognosis remains poor and overall efficacy is still unsatisfactory. Chemotherapy resistance is the most important reason for the poor outcome. Much progress has been made in the study of chemotherapy resistance of HCC;however, the specific mechanisms of progression of HCC have still only been partially established.Therefore, the mechanism of chemotherapy resistance in HCC requires more research.AIM To investigate the effect of miR-34 a expression on the growth inhibition of HepG2 cells by doxorubicin.METHODS A recombinant lentiviral vector containing miR-34 a was constructed and transfected into HepG2 cells. The expression of miR-34 a was detected by reverse transcription-polymerase chain reaction(commonly known as RT-PCR) before and after transfection. Cells were exposed to 2 μM doxorubicin or phosphatebuffered saline before and after transfection. Cell viability in each group was detected by MTT assay, and cell cycle and apoptosis were detected by flow cytometry. Changes in expression levels of phospho(p)-p53, sirtuin(SIRT) 1,cyclin D1, cyclin-dependent kinase(CDK) 4, CDK6, BCL-2, multidrug resistance protein(MDR) 1/P glycoprotein(P-gp), and AXL were detected by Western blotting.RESULTS Recombinant lentiviral vector LV-hsa-mir-34 a was successfully constructed by restriction endonuclease digestion and sequencing. RT-PCR showed that expression of miR-34 a in HepG2 cells was significantly upregulated after transfection(P < 0.01). MTT assay showed that growth of HepG2 cells was inhibited after upregulation of miR-34 a, and viability was significantly decreased after combined treatment with doxorubicin(P < 0.01). Flow cytometry showed that the number of HepG2 cells in G1 phase increased, and G1 phase arrest was more obvious after intervention with doxorubicin(P < 0.01). The apoptosis rate of HepG2 cells was increased after upregulation of miR-34 a, and became more obvious after intervention with doxorubicin(P < 0.01). Western blotting showed that upregulation of miR-34 a combined with treatment with doxorubicin caused significant changes in the expression levels of p-p53, SIRT1, cyclin D1, CDK4,CDK6, BCL-2, MDR1/P-gp and AXL proteins(P < 0.01).CONCLUSION MiR-34 a may enhance the inhibitory effect of doxorubicin by downregulating MDR1/P-gp and AXL, which may be related to p53 expression.

Incomplete radiofrequency ablation promotes the development of CD133+cancer stem cells in hepatocellular carcinoma cell line HepG2 via inducing SOX9 expression

Background: Cancer stem cells(CSCs) accelerate the growth of hepatocellular carcinoma(HCC) residual after incomplete radiofrequency ablation(In-RFA). The present study aimed to detect the effects of In-RFA on stemness transcription factors(STFs) expression which are important for the production and function of CSCs, and to find which STFs promote HCC stemness after In-RFA. Methods: HepG2 cells were used for in vitro and in vivo studies. Flow cytometry and sphere-formation assays were used to detect the level and function of CD133~+ CSCs in the models. PCR array and ELISA were applied to analyze the altered expression of 84 STFs in CD133~+ CSCs in two models. Specific lentiviral shRNA was used to knockdown STFs expression, followed by detecting In-RFA’s effects on the levels and function of CD133~+ CSCs. Results: In-RFA was identified to induce CD133~+ CSCs and increase their tumorigenesis ability in vitro and in vivo. The mRNA levels of 84 STFs in CD133~+ CSCs were detected by PCR array, showing that 15 and 22 STFs were up-regulated in two models, respectively. Meanwhile, the mRNA levels of seven common STFs were up-regulated in both models. ELISA assay demonstrated that only the protein of sex determining region Y-box 9(SOX9) was up-regulated in both models, the protein levels of the other 6 common STFs did not increase in both models. Finally, SOX9 was identified to play an important role in inducing, maintaining stemness and promoting tumorigenesis ability of CD133~+ CSCs in both models. Conclusion: In-RFA-induced SOX9 stimulates CD133~+ CSCs proliferation and increases their tumorigenesis ability, suggesting that SOX9 may be a good target for HCC treatment.

Salvianolic acid B modulates the expression of drug-metabolizing enzymes in HepG2 cells

BACKGROUND: Enzymes involved in drug and xenobiotic metabolism have been considered to exist in two groups: phase I and phase II enzymes. Cytochrome P450 isoenzymes (CYPs) are the most important phase I enzymes in the metabolism of xenobiotics. The products of phase I metabolism are then acted upon by phase II enzymes, including glutathione S-transferases (GSTs). Herbs that inhibit CYPs such as CYP3A4 or that induce GSTs may have the potential to protect against chemical carcinogenesis since the mutagenic effects of carcinogens are often mediated through an excess of CYP-generated reactive intermediates. This study was designed to investigate the effects of salvianolic acid B (Sal B), a pure compound extracted from Radix Salviae Miltiorrhizae, a Chinese herb, on cell proliferation and CYP1A2 and CYP3A4 mRNA expression in the presence or absence of rifampicin, a potent inducer of CYPs and GST protein expression in HepG2 cells. METHODS: HepG2 cells were incubated with different concentrations of Sal B. Cell proliferation was determined by SYTOX-Green nucleic acid staining. CYP3A4 and CYP1A2 mRNA expression was assayed by real-time PCR. GST protein expression was analyzed by Western blotting. RESULTS: Low concentrations of Sal B (0-20 μmol/L) had no significant effects on cell proliferation, while higher concentrations (100-250 μmol/L) significantly inhibited proliferation in a concentration-dependent manner. Ten μmol/L Sal B, but not 1 μmol/L, down-regulated CYP3A4 and CYP1A2 mRNA expression after 24 hours of incubation, whereas both 1 and 10 μmol/L Sal B down-regulated CYP3A4mRNA expression after 96 hours of incubation; moreover, 1 and 10 μmol/L Sal B inhibited CYP3A4 mRNA expression induced by rifampicin. Both 1 μmol/L and 10 μmol/L Sal B increased GST expression. CONCLUSION: Sal B inhibits CYP3A4 and CYP1A2 mRNA expression and induces GST expression in HepG2 cells.

Triterpenoid of avocado (Persea americana) seed and its cytotoxic activity toward breast MCF-7 and liver HepG2 cancer cells

Objective:To determine the structure of triterpenoid isolated from avocado seeds and the cytotoxic effect on MCF-7 and Hep G2 cells.Methods:The powder sample was macerated with ethanol,followed with separation of the extract by column chromatography.The target compound was monitored on thin layer chromatography plate and reagent Lieberman–Buchard.The isolated compound was characterized by spectral analysis,mainly ultraviolet,infrared,and liquid chromatographymass spectroscopy and their spectroscopic data with those reported in literature were compared.In vitro cytotoxic activity was investigated against Vero,MCF-7,and Hep G2 cell lines using MTT assay.Results:A triterpenoid compound was isolated from ethanol extract.The extracts,fraction(F3),and the isolated compound showed a significant cytotoxic activity against all investigated cell lines.MTT assay showed that the triterpenoid isolate inhibited cell proliferation of MCF-7 and Hep G2 cell line with the IC50 values of 62 mg/m L and 12 mg/m L,respectively,and was safe to normal cells.Conclusions:The results of the present study reveal that triterpenoid from avocado seeds have the potential for further development as anticancer agents.

Autophagy in anti-apoptotic effect of augmenter of liver regeneration in HepG2 cells

AIM:To investigate the role of autophagy in the antiapoptotic effect of augmenter of liver regeneration(ALR).METHODS:Autophagy was induced through serum deprivation.An ALR-expressing plasmid was transfected into HepG2 cells,and autophagic flux was determined using fluorescence microscopy,electron microscopy,Western blot and quantitative polymerase chain reaction(q PCR) assays.After ALR-expressing plasmid transfection,an autophagy inhibitor [3-methyladenine(3-MA)] was added to HepG2 cells,and apoptosis was observed using fluorescence microscopy and flow cytometry.RESULTS:Autophagy was activated in HepG2 cells,peaking at 24 h after serum deprivation.Microtubuleassociated protein light chain three-II levels were higher in HepG2 cells treated with ALR than in control cells,fluorescence microscopy,electron microscopy and q PCR studies showed the similar trend,and p62 levels showed the opposite trend,which indicated that ALR may play an important role in increasing autophagy flux.The numbers of apoptotic cells were substantially higher in HepG2 cells treated with both ALR and 3-MA than in cells treated with ALR alone.Therefore,the protective effect of ALR was significantly attenuated or abolished when autophagy was inhibited,indicating that the anti-apoptotic effect of ALR may be related to autophagy.CONCLUSION:ALR protects cells from apoptosis partly through increased autophagy in HepG2 cells and may be valuable as a new therapeutic treatment for liver disease.

Curcuma angustifolia ameliorates carbon tetrachloride-induced hepatotoxicity in HepG2 cells and Swiss albino rats

Objective:To determine the antioxidant and hepatoprotective potential of methanol extract of rhizome of Curcuma angustifolia(MECA)against carbon tetrachloride(CCl4)-induced hepatic damage in vitro and in vivo.Methods:DPPH,ABTS and reducing power assays were performed to estimate the antioxidant effect of MECA.In vitro cytotoxicity of MECA against HepG2 cells was evaluated,whereas serum biochemical parameters and levels of antioxidative enzymes were measured in vivo and in vitro.Additionally,histopathological studies were estimated in order to investigate the hepatoprotective efficacy of MECA.Furthermore,GC-MS analysis of the extract was performed to identify the chemical components.Results:MECA exhibited strong antioxidant activity and attenuated CCl4-induced decrease in the viability of HepG2 cells.Additionally,MECA significantly restored the ALT,AST,ALP,TP and albumin level in comparison with the CCl4 group.After pre-treatment with MECA,effects of SOD,CAT and GSH were increased as well as lipid peroxidation amount decreased on CCl4-induced hepatotoxicity in in vitro and in vivo model.Furthermore,histopathological observation confirmed that MECA reduced liver injury induced by CCl4 in rats.GC-MS analysis confirmed the presence of bioactive constituents such as α-tocopherol(12.27%),phytol(7.61%),squalene(3.71%),β-sitosterol(2.19%),eugenol(2.59%),curcumenol(1.20%),β-elemene(1.00%)and eucalyptol(0.89%).Conclusions:MECA contains antioxidant and hepatoprotective constituents such asα-tocopherol,phytol,squalene and eugenol and exerts hepatoprotective effect both in vitro and in vivo.

The protective effects of peptides from Chinese baijiu on AAPH-induced oxidative stress in HepG2 cells via Nrf2 signaling pathway

Antioxidant peptides have been widely reported.However,only a few reports have been published examining the antioxidant peptides derived from Chinese baijiu.In this study,6 novel peptides derived from Chinese baijiu were identified successfully using high-performance liquid chromatography-quadrupoletime-of-flight mass spectrometry(HPLC-QTOF-MS)with a concentration of 0.835–24.540μg/L.The underlying molecular mechanisms were investigated,and their cytoprotective effects were examined against 2,2’-azobis(2-methylpropanimidamidine)dihydrochloride(AAPH)-induced oxidative stress in Hep G2 cells.The results showed that these peptides exerted protective effects by suppressing reactive oxygen species(ROS)generation,preventing malondialdehyde(MDA)formation,and upregulating cellular antioxidant enzyme activities(SOD,CAT,and GSH-Px)in a dose-dependent manner.Further experiments proved that these peptides exerted antioxidant effects via Nrf2/ARE-mediated signaling pathway by promoting Nrf2 nuclear translocation,inhibiting ubiquitination,and enhancing transcription capacity of Nrf2 in Hep G2 cells.These findings provide the molecular basis for the effects of antioxidant peptides derived from Chinese baijiu,which is important for a deeper understanding of the relationship between human health and moderate drinking.

Effects of Traditional Chinese Medicinal Plants on Antiinsulin Resistance Bioactivity of DXMS-Induced Insulin Resistant HepG2 Cells

Medicinal plants have a long history of use in China to treat diabetic symptoms.Ancient Chinese medical manuscripts and ethnobotanical surveys document plant remedies that continue to be actively used in China for the treatment of diabetic symptoms.Based on a systematic ancient Chinese medical manuscripts review in combination with ethnobotanical survey,16 medicinal plants for the traditional treatment of diabetic symptoms were identified for the evaluation of anti-insulin resistance bioactivity.The biological activity of 16 medicinal plants was tested on dexamethasone(DXMS)-induced insulin resistant HepG2 cells.The result shows that 11 of the 16 medicinal plants enhanced glucose uptake of DXMS-induced insulin resistant HepG2 cells,thereby demonstrating their ability to increase insulin sensitivity,other five medicinal plants including Astragalus membranaceus were found ineffective.The study shows that ancient Chinese medical manuscripts and ethnobotanical surveys on plants for the prevention and treatment of diabetic symptoms provide a promising knowledge base for drug discovery to mitigate the global diabetes epidemic.

siRNA of ADAM17 gene induces apoptosis,proliferation inhibition and enhances the effects of genistein on HepG2 cells

Objective：To investigate the effects of siRNA of ADAM17 gene and genistein on apoptosis and the inhibition of proliferation in HepG2 cells in an attempt to seek an effective therapy for hepatocellular carinoma. Methods：Cells were divided into control groups and experimental groups and siRNA was used to silence the ADAM17 gene, alone and in combination with genistein. Cells were harvested at several time periods and assessed for proliferation and apoptosis. Proliferation was assayed by MTT at 24, 48, 72 and 96 hours following treatment and apoptosis was assessed by flow cytometric analysis at 48 hours. Results：In siRNA groups, proliferation of cells was significantly inhibited compared to the control groups at 24, 48 and 72 hours（P 〈 0.05）, and apoptosis was significantly increased at 48 hours（P〈 0.01）; In genistein groups, proliferation was inhibited at 24, 48, 72 and 96 hours, and the apoptosis ratio was significantly increased at 48 hours（P〈 0.01）; while in the groups that received the combination of siRNA transfection and genistein treatment, there was a further significant decrease of proliferation and increase in apoptosis compared with either treatment alone. Conclusion：The ADAM17 gene could be an effective target, and genistein could be a useful agent, in the treatment of hepatocellular carcinoma, siRNA of ADAM17 gene and genistein both inhibited HepG2 cells proliferation and promoted apoptosis, and further, the combination of these treatments had a greater effect than either treatment alone.

The Effects of HBx Gene on the Expression of DNA Repair Enzymes hOGG1 and hMYHα mRNA in HepG2 Cells

To observe the alteration in the expression of DNA repair enzymes hOGG1 and hMYHa and the change in 8-OHdG levels in the HBx gene-transfected cells HepG2/HBx and to explore the mechanisms of the HBV-associated hepatocellular carcinoma, the gene-transfected cells HepG2/HBx which stably expressed HBx was established, and the effect of HBx on the cell cycle and proliferation of HepG2 was examined. By using the β-actin as the interior control, real-time polymerase chain reaction （Real-time qPCR） was employed to quantitatively detect the expression of DNA repair enzymes hOGG1 and hMYHα in the HepG2/HBx, the control cells HepG2 and HepG2 transfected with pcDNA3.1 vector （HepG2/pDNA3.1）. The 8-OHdG levels were determined by HPLC/ECD in the established gene-transfected cells HepG2/HBx and the control cells HepG2 and HepG2/pcDNA3.1. Our results showed that the expression of DNA repair enzyme hMYHα in the HepG2/HBx （0.021±0.007） was significantly lower than that of HepG2 （0.099±0.041） （P〈0.05） and HepG2/pDNA3.1 （0.121±0.005） （P〈0.05）. However, the no significant differences existed in the expression of DNA repair enzyme hOGG1 among the three cell strains （P〉0.05）. The 8-OHdG level in the HepG2/HBx was significantly higher than that in HepG2 and HepG2/pcDNA3.1 （P〈0.05）. It is concluded that HBx gene may inhibit the expression of DNA repair enzyme hMYHα mRNA to impair the ability to repair the intracellular DNA oxidative damage, to increase the oxidative DNA-adduct 8-OHdG and to affect the nucleotide excision repair function, thus participate in the occurrence and development of hepatocellular carcinoma.