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.

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.

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.

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.

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.

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.

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.

Artemyrianins A-G from Artemisia myriantha and Their Cytotoxicity Against HepG2 Cells

Four new sesquiterpenoids,artemyrianins A-D(1-4),and three new norlignans,artemyrianins E-G(5-7),together with five known compounds(8-12),were isolated from the aerial parts of Artemisia myriantha(Asteraceae).The new compounds were established by spectroscopic data analyses(HRMS,IR,1D and 2D NMR),and their absolute configurations were confirmed by the single-crystal X-ray diffraction or ECD calculations.The isolates showed cytotoxicity against HepG2 cells with IC50 values ranging from 33.3 to 145.2μM.

Combination of metformin and curcumin exhibits synergistic inhibitory effects on tumor growth and metastasis in HepG2 cells

OBJECTIVE Hepatocel ular carcinoma(HCC)is the most common cause of cancer-related mortality,with high incidence rates,robust metastatic propensity and acquired resistance to therapy.Metformin,an extensively prescribed and well-tolerated first-linetherapeutic drug for type 2 diabetes mellitus,has recently been identified as a potential and attractive anticancer adjuvant drug combined with chemotherapeutics to improve treatment efficacy and lower doses.Curcumin,a botanical extracts,has been shown antitumorigenic properties.This study aims to investigate the combinational effect of metformin and curcumin on inbibition of tumor growth and metastasis in Hep G2 cells and the possible underlying mechanisms.METHODS The cell proliferation was determined by MTT,CCK-8 and colony formation assay.The protein expression was detected by Western blotting.Activity of MMP-2 and MMP-9 was estimated by gelatin zymography.Flow cytometry analysis was used to evaluate the influence of metformin and curcumin on cell cycle arrest and apoptosis,and morphology observation of apoptosis was detected by Hoechst33342.Scratch and transwell assay was performed to detect the cell migration and invasion.The suppression of this combination therapy oncapillary tube formation was detected by tube formation assay.RESULTS Combination of metformin and curcumin induced stronger inhibition on Hep G2 cells proliferation than monotherapywhich related to induction of cell cycle arrest in G2/M phase and apoptosis through regulation of the protein expression of cyclin B and Bcl-2/Bax.Moreover,the co-treatment of metformin with curcumin exerted an enhanced inhibitory effect on Hep G2 cell metastasis and synergistically inhibited the tube formation of HUVEC cells.The suppression of PI3K/AKT/m TOR pathway and inhibition the protein expression of STAT3,MMP9,MMP2 and VEGF might involve in this synergistic effects of combination treatment.CONCLUSION Combination of metformin and curcumin inhibited Hep G2 cells proliferationmore effectively than monotherapy and synergistically induced a greater inhibition on migration and invasion of Hep G2 cells.

Gene expression profile analysis reveals the effect of metformin treatment on HepG2 cells

Metformin is a first-line drug in the fight against type 2 diabetes.In recent years,studies have shown that metformin has some preventive and therapeutic effects on liver cancer,but the effects of metformin on the gene expression of liver cancer cells are not fully known.This study focused on the differences in the gene expression profiles in liver cancer cells treated with or without metformin.A total of 153 differentially expressed genes(DEGs)(FC>2 and q-values<0.001)were found,including 77 upregulated genes and 76 downregulated genes.These DEGs are involved in mitogen-activated protein kinase(MAPK),nuclear factor-kappa B(NF-κB),cell adhesion molecules(CAMs),and leukocyte transendothelial migration signaling pathways.These findings reveal the effects of metformin treatment on gene expression profiles in liver cancer cells and provide new clues for unveiling the mechanism of the antitumor effects of metformin.

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.

Differential Expression of Genes in HepG2 Cells Caused by UC001kfo RNAi as Shown by RNA-seq

The differential expression of genes in HepG2 cells caused by UC001 kfo RNAi was investigated using RNA-seq. HepG2 cells were infected by Lenti-sh UC001 kfo lentivirus particles. The expression of UC001 kfo m RNA in the HepG2-sh UC001 kfo cell line was detected by real-time PCR. RNA-seq technology was used to identify the difference in the expression of genes regulated by lnc RNA UC001 kfo in the HepG2 cell line. Gene ontology and signaling pathway analysis were performed to reveal the biological functions of the genes encoding of significantly different m RNAs. The results showed that m RNAs were differentially expressed between the HepG2-sh UC001 kfo cell line and the HepG2 cell line. The UC001 kfo m RNA was significantly down-regulated in the stable cell line HepG2-sh UC001kfo（P〈0.001）. Additionally, we found 19 signaling pathways or functional classifications encompassing 30 genes that played a role in cancer characteristics, cell adhesion, invasion and migration. The results also showed that the expression of many genes associated with cancer cell invasion and metastasis was decreased with the down-regulation of the lnc RNA UC001 kfo. Lnc RNA UC001 kfo may play a role in regulating cancer cell invasion and metastasis. It was suggested that m RNAs were differentially expressed in the HepG2 cell line after the down-regulation of lnc RNA-UC001 kfo. Some took part in the extracellular matrix, cell adhesion, motility, growth, and localization. The genes encoding of differentially expressed m RNAs may participate in cell invasion and metastasis.

AstragalosideⅣameliorates insulin induced insulin resistance in HepG2 cells through reactive oxygen species mediated c-Jun N-terminal kinase pathway

OBJECTIVE:To investigate the effects and elucidate the mechanism of Astragaloside IV(AS-IV)for insulin resistance(IR)and type 2 diabet es mellitus(T2DM).METHODS:CCK8 kit was used to detect cell viability,glucose detection kit was used to detect the concentration of glucose in cell supernatant,reactive oxygen species(ROS)detection kit and Western blot were used to explore the mechanism of Astragaloside IV(AS-IV)in improving IR.A diabetic rat model was also established by feeding high sugar and fat diet and streptozotocin(STZ)injection.After treatment with AS-IV,rosiglitazone(ROZ),or normal saline,the fasting blood glucose(FBG),C peptide(C-P),tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and the glucose tolerance were assessed.RESULTS:AS-IV could effectively reduce the content of ROS and increase the glucose uptake in high insulintreated IR-type HepG 2 cells.The results of molecular mechanisms indicated that AS-IV could improve insulin resistance by reducing JNK phosphorylation and regulating c-Jun N-terminal kinase(JNK)downstream protein expression.Additionally,AS-IV could significantly reduce the levels of FBG,TNF-α,IL-6 and the glucose tolerance in diabetic rats(P<0.05 or<0.01).The high and medium dose groups of AS-IV could significantly increase the C-P levels in diabetic rats(P<0.05 or<0.01).CONCLUSIONS:Our results indicated that AS-IV improve liver IR through the JNK pathway and ROS,which meant a new molecular target for the treatment of diabetes.The AS-IV also helped to prevent and improved the insulin resistance of rats.

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.

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.

Dynamic monitoring of the cytotoxic effects of protoberberine alkaloids from Rhizoma Coptidis on HepG2 cells using the xCELLigence system

AIM: To investigate the cytotoxic effects of the six protoberberine alkaloids(PAs) from Rhizoma Coptidis on HepG2 cells. METHOD: A systematic screening was conducted to investigate the dynamic response of HepG2 cells to the PAs using the impedance-based xCELLigence system. Cisplatin was selected as the positive control. The real time, concentration-response curves and the 50% inhibitory concentrations(IC50) were acquired to evaluate the anticancer activity of the PAs. RESULTS: All of the six PAs inhibited cell growth and induce death in HepG2 cells in a time- and concentration-dependent manner. The IC50 values of cisplatin, berberine, columbamine, coptisine, epiberberine, jatrorrhizine, and palmatine were 5.13, 42.33, 226.54, 36.90, 302.72, 383.54, and 456.96 μg·mL-1, respectively. The results obtained using the xCELLigence system corresponded well with those of the conventional methods. CONCLUSION: The xCELLigence system is a reliable and efficient tool for real-time screening of the cytotoxic effect of compounds in cell-based in vitro assays. Coptisine and berberine, with methylenedioxy group at C2 and C3 on the phenyl ring showed stronger effect.than the other four PAs. However, compared with cisplatin, the six PAs didn't show obvious cytotoxic effect on HepG2 cells.These results provided some useful data for the evaluation of the anticancer compounds, and the clinical application of traditional Chinese medicine.

Effect of environmental factors on chemoresistance of HepG2 cells by regulating hypoxia-inducible factor-1α

Background Accumu1αting evidence demonstrates that the microenvironment of the host has an important effect on the chemoresistance of tumors. We also found that the formation of intrinsic multidrug resistance is re1αted to environmental factors that are common with tumor growth of hepatocellu1αr carcinoma. The aim of this study was to explore the molecu1αr mechanisms by which multidrug resistance of hepatocellu1αr carcinoma is induced by the microenvironment. In particu1αr, the regu1αtion of nuclear transcription factor （hypoxia-inducible factor-1α, HIF-1α） activation in the process of multidrug resistance formation was investigated. Methods HepG2 cells were exposed to different microenvironmental conditions respectively, such as hypoxia, stimu1αtion of glucose deprivation and transfection of p1αsmid PcDNA3/HBx. In the HepG2 cells, the expression of the re1αted MDR proteins, HIF-1α protein expression and localization, activity of extracellu1αr signal-regu1αted kinase /mitogen-activated protein kinase （ERK/MAPK） were detected. Specific inhibitor U0126 was used to block ERK/MAPK signal pathway, the alteration of HIF-1α and the re1αted MDR proteins were investigated. Multivariate analysis of variance （MANOVA） repeated measures and one-way analysis of variance （ANOVA） followed by Tukey test or t-test were used to determine differences over time and effects of the treatments. Results The above three microenvironment factors increase the expression of the re1αted MDR proteins （including P-gp, LRP, and MRP1） and induce MDR of HepG2 cells. HIF-1α was induced at the protein and mRNA levels and the nuclear translocation was also increased. The activity of ERK/MAPK was also increased in HepG2 cells. But when ERK/MAPK pathway was inhibited, the mRNA and protein decreased. Inhibition of ERK/MAPK significantly reduced HIF-1α, whereas HIF-1α mRNA levels were not affected. expression of MDR1, MRP1, and LRP was to some extent activated HIF-1α protein and the nuclear translocation of Conclusions The microenvironmental factors could induce MDR of HepG2 cells by the activity of HIF-1α. The activity of HIF-1α is regu1αted by the ERK/MAPK pathway at the phosphory1αtion level. As an important nuclear transcription factor, HIF-1α controls the transcription of MDR-re1αted genes and the synthesis of their corresponding proteins by ERK/MAPK signal pathway in HepG2 cells.

Effect of high exposure of chlorogenic acid on lipid accumulation and oxidative stress in oleic acid-treated HepG2 cells

Objective：To evaluate the effect of high concentration of chlorogenic acid（CGA）on non-alcoholic fatty liver disease（NAFLD）in normal and oleic acid（OA）treated Hep G2 cells,as well as the underlying mechanism involved in the fat accumulation,oxidative stress and insulin resistance（IR）induced by CGA treatment.Methods：OA（0.5 mmol/L）induced hepatic steatosis was established in Hep G2 cells as an in vitro model of NAFLD.The normal and OA-treated Hep G2 cells were treated by CGA（0,0.5,1,and 2 mmol/L）for24 h,then cellular lipid droplets,reactive oxygen species（ROS）,and glucose uptake were evaluated by Oil Red O staining and cellular biochemical assays,respectively.Signaling pathways involved in adipogenesis including SREBP-1c and PNPLA3,oxidative stress,and IR including CYP2E1 and CYP4A,were investigated by Western blot and RT-q PCR.Results：CGA（0.5,1,and 2 mmol/L）treatment increased the cellular lipid droplets and the expression of SREBP-1c and PNPLA3 in the tested cells.Additionally,2-NBDG uptake was significantly increased,whereas the cellular ROS and protein levels of CYP2E1 and CYP4A were significantly decreased in OA-treated cells.Conclusion：Our results suggest that high concentrations of CGA ameliorated OA-induced oxidative damage and IR likely by inhibiting the expression of CYP2E1 and CYP4A,and promoted lipid accumulation by inducing the expression of SREBP-1c and PNPLA3 in the tested cells.

Effect of Fanbaicao(Herba Potentillae Discoloris) oil on the expression of p21 and CDK4 in HepG2 cells

OBJECTIVE:To research the anti-cancer mechanism of the Traditional Chinese Medicine Fanbaicao(Herba Potentillae Discoloris) oil in the human hepatoma cell line Hep G2.METHODS:Gas chromatography was used to analyze the components of Fanbaicao(Herba Potentillae Discoloris).We tested the inhibitory effect of Fanbaicao(Herba Potentillae Discoloris) oil on the human hepatoma cell line Hep G2 in vitro using 3-(4,5-Dimet hylt hiazol-2-yl)-2,5-dip henyltetrazoliumbromide assays.Fluorescence activating cell sorter analysis was used to examine the levels of apoptosis,and western blot and immunofluorescence were used to detect the expression of p21,p-p21 and CDK4 proteins.RESULTS:Fanbaicao(Herba Potentillae Discoloris)oil contains 45 ingredients,and L-ascorbic acid 2,6-bispalmitate was the main component and accounted for 44.96% of total drive-off peak area.Other components included(Z)-14-met hyl-8-exadecenal-acetal(8.56%),phytol(7.74%) and lauric acid(6.31%).Fanbaicao(Herba Potentillae Discoloris)oil treatment reduced the proliferation of Hep G2 cells and the half growth inhibition concentration(IC50) was 2.03 mg/m L.Furthermore,we also observed significantly increased Hep G2 cell apoptosis in a dose-dependent manner(P < 0.05).Fanbaicao(Herba Potentillae Discoloris) oil significantly increased the expression of p21 and p-p21 and significantly decreased the expression of CDK4 in Hep G2 cells compared with controls(P < 0.01).CONCLUSION:Our results showed that Fanbaicao(Herba Potentillae Discoloris) oil has anti-cancer activities in Hep G2 cells,which is probably related to the upregulation of p21 and p-p21 and downregulation of CDK4 expression.