Human Liver Carcinoma Cell Line Research Articles

Evaluation of DNA/Protein interactions and cytotoxic studies of copper(II) complexes incorporated with N, N donor ligands and terpyridine ligand

A series of four new copper(II) heteroleptic complexes, [Cu(2‴-pytpy) (L)] (NO3)2·2H2O (1–4), where 2‴-pytpy=4′-(2′′′-Pyridyl)-2, 2′:6′, 2′′-terpyridine, L=bipyridyl (bpy), 1, 10 phenanthroline(phen), dipyridoquinoxaline(dpq) and dipyridophenazine (dppz) were synthesized and characterized by spectroscopic techniques. Further, the molecular structure of the complex (2) was confirmed by single crystal X-ray diffraction technique and the data revealed a penta coordinated, distorted square-pyramidal geometry with triclinic system. The interactions of four complexes with calf thymus DNA and bovine serum albumin (BSA) were investigated by electronic absorption, fluorescence and circular dichroism spectroscopy techniques. Spectral studies substantiated an intercalative binding mode of metal complexes with ct-DNA. Significant binding interactions of the complexes with protein have been further revealed from fluorescence studies. Furthermore, all the four complexes show potential cytotoxicity towards the human liver carcinoma cell line (HepG-2).

Essential oil components decrease pulmonary and hepatic cells inflammation induced by air pollution particulate matter

Outdoor air pollution and fine particulate matter (PM) were recently classified as carcinogenic to humans by the International Agency for Research on Cancer. The exposure to airborne particulate matter also contributes to cardiovascular and respiratory diseases, which are major public health concerns. Up to now, no work has evaluated the ability of essential oils as an alternative medicine to relieve the adverse health effects caused by airborne particulate matter. Here, we investigated for the first time the effects of four essential oil components, trans-anethole, estragole, eugenol and isoeugenol, on the reduction in inflammation induced by particulate matter with an aerodynamic diameter below 2.5 μm (PM2.5), in human bronchial epithelial (BEAS-2B) and human liver carcinoma (HepG2) cell lines. Anethole is a flavor component of anise and fennel, estragole is occurring in basil, eugenol occurs in clove bud oil and isoeugenol occurs in ylang-ylang. Essential oil components were tested either as free or hydroxypropyl-β-cyclodextrin-encapsulated forms. Control experiments showed that particulate matter (PM2.5) induced inflammation by secretion of pro-inflammatory cytokines IL-6 and IL-8. Our results show that the addition of either free or encapsulated essential oil components to particulate matter exposed cells decreased up to 96 % the cytokine IL-6 level, and by up to 87 % the cytokine IL-8 level. Overall our findings evidence for the first time that natural essential oil components counteract the inflammatory effects of particulate matter and that encapsulation in cyclodextrins preserved their properties.

Synthesis, characterization of 1,2,4-triazole Schiff base derived 3d-metal complexes: Induces cytotoxicity in HepG2, MCF-7 cell line, BSA binding fluorescence and DFT study

Two novel Schiff base ligands H2L1 and H2L2 have been synthesized by condensation reaction of amine derivative of 1,2,4-triazole moiety with 2-hydroxy-4-methoxybenzaldehyde. Co(II), Ni(II), Cu(II) and Zn(II) of the synthesized Schiff bases were prepared by using a molar ratio of ligand:metal as 1:1. The structure of the Schiff bases and synthesized metal complexes were established by 1H NMR, UV–Vis, IR, Mass spectrometry and molar conductivity. The thermal stability of the complexes was study by TGA. Fluorescence quenching mechanism of metal complexes 1–4 show that Zn(II) and Cu(II) complex binds more strongly to BSA. In DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. The spectral data shows that the ligands behaves as binegative tridentate. On the basis of the spectral studies, TGA and DFT data an octahedral geometry has been assigned for Co(II), Ni(II), square planar for Cu(II) and tetrahedral for Zn(II) complexes. The anticancer activity were screened against human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (Hep-G2). Result indicates that metal complexes shows increase cytotoxicity in proliferation to cell lines as compared to free ligand.

Abstract 4421: Molecular features of hepatocellular carcinoma arising from non-alcoholic fatty liver

Abstract (Background) The incidence of hepatocellular carcinoma (HCC) arising from non-alcoholic fatty liver (NAFL) has been recently increasing according to increase of patients having metabolic syndrome. HCC, which shows steatosis, cellular ballooning, Mallory-Denk bodies, inflammation and fibrosis in cancer tissue, are recognized as steatohepatitic HCC (SH-HCC). This HCC phenotype is more frequently found in NAFL patients than in viral-hepatitic patients. (Purpose) The purpose of this study is to elucidate molecular features of SH-HCC with NAFL background. (Methods) To profile SH-HCC-related genes, mRNA expression patterns in SH-HCCs were compared with those in viral hepatitis HCCs by RNA array. RNA expression of the identified SH-HCC related gene was analyzed in three human liver carcinoma cell lines (HepG2, Huh7, and HLE) in normal conditioned medium. By mimicking the lipid-rich environment, these cell lines were also cultured in the presence of saturated (palmitic or stearic acid, recognized as endoplasmic reticulum stressors) or unsaturated fatty acids (oleic acid: OA). To address the role of SH-HCC-related gene, cell proliferation and apoptosis were assessed in the presence or absence of fatty acids, by knock-down of the objective gene using siRNA. (Results) (1) Caveolin (cav)-1 and -2 were identified as SH-HCC related genes (1.63 and 1.58 fold expression of cav-1 and -2, respectively) by RNA microarray analysis. (2) HLE and Huh7 showed high and low expression of both cav-1 and -2 mRNA, whereas HepG2 did not express either on qRT-PCR. (3) In the presence of OA, HepG2 and Huh7 did not well proliferate, whereas HLE cell proliferation increased with concentration of OA and culture duration. (4) Knock-down of cav-1 and -2 canceled OA-induced increase of cell proliferation. In the same condition, expression of cleaved caspase 3 was increased, suggesting the promotion of apoptosis. (Consideration) Cav-1 and -2, the important protein for endocytosis and cellular signaling, are highly expressed in SH-HCC. These proteins would increase cell proliferation and inhibit apoptosis in the presence of unsaturated fatty acids, presumably by using these fatty acids as energy source or by caveolae-related anti-apoptotic process. Citation Format: Makoto Takeda, Takanori Sakaguchi, Ryouta Kiuchi, Takanori Hiraide, Yasushi Shibasaki, Yoshihumi Morita, Hirotoshi Kikuchi, Mitsutoshi Setou, Hiroyuki Konno. Molecular features of hepatocellular carcinoma arising from non-alcoholic fatty liver. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4421.

Redox-responsive star-shaped magnetic micelles with active-targeted and magnetic-guided functions for cancer therapy

Highly efficient delivery of therapeutic agents to target sites is of great importance for achieving excellent therapeutic efficacy in cancer treatment. Here, we report a redox-responsive star-shaped magnetic micelle with both active-targeted and magnetic-guided functions. The magnetic star-shaped micelles are formed by self-assembly of four-arm poly(ethylene glycol) (PEG)-poly(ε-caprolactone) (PCL) copolymers with disulfide bonds as intermediate linkers. Anticancer drug doxorubicin (DOX) and magnetic iron oxide nanoparticles (Fe3O4) are simultaneously encapsulated into the hydrophobic cores. PBA ligands are chemically conjugated to the end of the hydrophilic PEG segments, endowing the active targeting of nanocarriers. Both qualitative and quantitative analyses of the intracellular uptake of these micelles with active-targeting and dual-targeting are performed in vitro by cultured with salic acid (SA)-positive tumor cells (human liver carcinoma cell line HepG2, human cervical cancer cell line HeLa) and SA-negative tumor cells (human breast adenocarcinoma cell line MCF-7, human non-small cell lung cancer cell line A549) in the presence or absence of a permanent magnetic field. In vivo biodistribution studies with active-targeting and dual-targeting and in vivo anti-tumor effect are carried out in detail after being applied to the BALB/c mice bearing mouse H22 hepatocarcinoma cells tumor model. These in vivo results demonstrate that a great amount of dual-targeted magnetic micelles accumulate around the tumor tissues by the magnetic-guiding and in turn are taken up by the tumor cells through SA-mediated endocytosis, leading to a high therapeutic efficacy to the artificial solid tumor. Statement of SignificanceA redox-responsive star-shaped magnetic micelle with both active-targeted and magnetic-guided functions was developed. Both qualitative and quantitative analysis of the intracellular uptake with dual-targeting of these micelles were performed in vitro by salic acid (SA)-positive tumor cells. The in vivo results demonstrate that a great amount of dual-targeted magnetic micelles accumulated around the tumor tissues, leading to a high therapeutic efficacy to artificial solid tumor.

The Mechanism by Which Amentoflavone Improves Insulin Resistance in HepG2 Cells.

Background: The aim of this study was to explore the mechanism by which amentoflavone (AME) improves insulin resistance in a human hepatocellular liver carcinoma cell line (HepG2). Methods: A model of insulin resistant cells was established in HepG2 by treatment with high glucose and insulin. The glucose oxidase method was used to detect the glucose consumption in each group. To determine the mechanism by which AME improves insulin resistance in HepG2 cells, enzyme-linked immunosorbent assay (ELISA) and western blotting were used to detect the expression of phosphatidyl inositol 3-kinase (PI3K), Akt, and pAkt; the activity of the enzymes involved in glucose metabolism; and the levels of inflammatory cytokines. Results: Insulin resistance was successfully induced in HepG2 cells. After treatment with AME, the glucose consumption increased significantly in HepG2 cells compared with the model group (MG). The expression of PI3K, Akt, and pAkt and the activity of 6-phosphofructokinas (PFK-1), glucokinase (GCK), and pyruvate kinase (PK) increased, while the activity of glycogen synthase kinase-3 (GSK-3), phosphoenolpyruvate carboxylase kinase (PEPCK), and glucose-6-phosphatase (G-6-Pase) as well as the levels of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and C reactive protein (CRP) decreased. Conclusions: The mechanism by which treatment with AME improves insulin resistance in HepG2 cells may involve the PI3K-Akt signaling pathway, the processes of glucose oxygenolysis, glycogen synthesis, gluconeogenesis and inflammatory cytokine expression.

Nanoceria Attenuated High Glucose-Induced Oxidative Damage in HepG2 Cells.

Hyperglycemia, a common metabolic disorder in diabetes, can lead to oxidative damage. The use of antioxidants can benefit the control and prevention of diabetes side effects. This study aims to evaluate the effect of nanoceria particles, as an antioxidant, on glucose induced cytotoxicity, reactive oxygen species (ROS), lipid peroxidation (LPO) and glutathione (GSH) content in a human hepatocellular liver carcinoma cell line (HepG2) cell line. In this experimental study, we divided HepG2 cells into these groups: i. Cells treated with 5 mM D-glucose (control), ii. Cells treated with 45 mM D- mannitol+5 mM D-glucose (osmotic control), iii. Cells treated with 50 mM D-glucose (high glucose), and iv. Cells treated with 50 mM D-glucose+nanoceria. Cell viability, ROS formation, LPO and GSH were measured and analyzed statistically. High glucose (50 mM) treatment caused significant cell death and increased oxidative stress markers in HepG2 cells. Interestingly, nanoceria at a concentration of 50 mM significantly decreased the high glucose-induced cytotoxicity, ROS formation and LPO. This concentration of nanoceria increased the GSH content in HepG2 cells (P<0.05). The antioxidant feature of nanoceria particles makes it an attractive candidate for attenuation of hyperglycemia oxidative damage in different organs.

Antioxidant, antimicrobial and cytotoxic potential of condensed tannins from Leucaena leucocephala hybrid-Rendang

Condensed tannins (CTs) are one of the promising compounds due to their potentially health-promoting qualities. In this study, CTs were extracted from a Leucaena leucocephala hybrid-Rendang and subjected to various biological studies including antioxidant (using Ferric reducing antioxidant power (FRAP), DPPH and ABTS radical scavenging assay), anti-microbial (against different pathogens) and cytotoxic activities (toward human breast adenocarcinoma (MCF-7), human colon carcinoma (HT29), human cervical carcinoma (HeLa) and human liver carcinoma (HepG2) cell lines) in cancer cells through in vitro experiments. The structural characteristics and purity of CTs extract were determined using 13C NMR. The results showed that CTs exhibited higher in vitro antioxidant activities (2257.12±80.55mgTEAC/gextract, 605.3±1.82mgTEAC/gextract and 1014.03±1.20mgTEAC/gextract in FRAP, ABTS and DPPH assay, respectively) and demonstrated anti-microbial activities toward selected Gram's positive and Gram's negative bacteria tested with MIC and MBC value at 6.25–50mg/mL. Furthermore, among other selected cancer cells, CTs also demonstrated cytotoxic activity toward human breast cancer cells (MCF-7) (IC50=38.33±2.08μg/mL). Characteristic of apoptosis such as cell shrinkage, nuclear condensation and apoptotic bodies were shown in MCF-7. These preliminary investigations have provided scientific rationale to use CTs as an alternative therapy for various oxidative and inflammatory associated diseases.

Evaluation of geno-toxicity of methyl parathion and chlorpyrifos to human liver carcinoma cell line (HepG2).

Insecticides and their residues are known to cause several types of ailments in human body. An attempt had been made to assess digitally the geno-toxicity of methyl parathion (MP) and chlorpyrifos (CP) to in vitro-grown HepG2 cell line, with Hoechst 33342 staining, comet, and micronucleus assays. Additionally, "acridine orange/ethidium bromide" (AO/EB) staining was done for the determination of insecticide-induced cytotoxicity, in corollary. Hoechst 33342 staining of cells revealed a decrease in live cell counts at 8-40mg/L MP and 15-70mg/L CP. Moreover, nuclear fragmentations in ranges 8 to 40mg/L MP and 15 to 70mg/L CP were recorded dependant on individual doses, increasingly with concomitant increases in comet tail length values. DNA fragmentation index measured in comet assays was 94.3 ± 0.57 at 40mg/L MP and 93.3 ± 2.08 at 70mg/L CP. Average micronuclei number was 59.0 ± 2.00 at 40mg/L MP and 62.6 ± 1.52 at 70mg/L CP, per 1000 cell nuclei, in micronucleus assay. Minimum inhibitory concentration (MIC) values with AO/EB staining for monitoring cytotoxicity were 4 and 10mg/L for MP and CP, respectively. Lethal concentration50 (LC50) values were 20.89mg/L MP and 79.43mg/L CP in AO/EB staining, for cytotoxicity with probit analyses. It was concluded that MP was comparatively more geno-toxic than CP to HepG2 cell. It was discernible that at lower levels of each insecticide, geno-toxicity was recorded in comparison to cytotoxicity.

Preparation and Characterization of Irinotecan Loaded Cross-Linked Bovine Serum Albumin Beads for Liver Cancer Chemoembolization Therapy

In this paper, a novel temporary embolization agent for transarterial chemoembolization of liver cancer was developed and tested. The Irinotecan loaded bovine serum albumin (BSA) beads were tried to be used as embolic agent of liver cancer therapy. BSA beads were prepared by a water-in-oil emulsion solvent diffusion method in soya oil and Span 85 was used as the emulsifier. The obtained BSA beads were able to swell 2.37-fold comparing to dried beads. Depending on the equilibrium swelling process, the Irinotecan was loaded with 9.8% total drug concentration and tested. In vitro drug release studies showed that a burst release of Irinotecan was achieved. Eventually BSA beads were completely degraded in a few weeks. CCK-8 assay demonstrated that BSA beads showed no cytotoxicity against human umbilical vein endothelial cells, and the Irinotecan loaded BSA beads showed comparable cytotoxicity against Hep G2, a human liver carcinoma cell line, as the traditional Irinotecan. In a rabbit model, it was found that BSA beads can successfully be transferred to liver and provide occlusion of small arteries. The present investigation suggested that the BSA beads are promising drug carriers and can potentially be used as temporary embolization agents in interventional oncology.

Trehalose-Based Block Copolycations Promote Polyplex Stabilization for Lyophilization and in Vivo pDNA Delivery.

The development and thorough characterization of nonviral delivery agents for nucleic acid and genome editing therapies are of high interest to the field of nanomedicine. Indeed, this vehicle class offers the ability to tune chemical architecture/biological activity and readily package nucleic acids of various sizes and morphologies for a variety of applications. Herein, we present the synthesis and characterization of a class of trehalose-based block copolycations designed to stabilize polyplex formulations for lyophilization and in vivo administration. A 6-methacrylamido-6-deoxy trehalose (MAT) monomer was synthesized from trehalose and polymerized via reversible addition–fragmentation chain transfer (RAFT) polymerization to yield pMAT43. The pMAT43 macro-chain transfer agent was then chain-extended with aminoethylmethacrylamide (AEMA) to yield three different pMAT-b-AEMA cationic-block copolymers, pMAT-b-AEMA-1 (21 AEMA repeats), -2 (44 AEMA repeats), and -3 (57 AEMA repeats). These polymers along with a series of controls were used to form polyplexes with plasmids encoding firefly luciferase behind a strong ubiquitous promoter. The trehalose-coated polyplexes were characterized in detail and found to be resistant to colloidal aggregation in culture media containing salt and serum. The trehalose-polyplexes also retained colloidal stability and promoted high gene expression following lyophilization and reconstitution. Cytotoxicity, cellular uptake, and transfection ability were assessed in vitro using both human glioblastoma (U87) and human liver carcinoma (HepG2) cell lines wherein pMAT-b-AEMA-2 was found to have the optimal combination of high gene expression and low toxicity. pMAT-b-AEMA-2 polyplexes were evaluated in mice via slow tail vein infusion. The vehicle displayed minimal toxicity and discouraged nonspecific internalization in the liver, kidney, spleen, and lungs as determined by quantitative polymerase chain reaction (qPCR) and fluorescence imaging experiments. Hydrodynamic infusion of the polyplexes, however, led to very specific localization of the polyplexes to the mouse liver and promoted excellent gene expression in vivo.

The hepatitis B virus receptor.

Hepatitis B virus (HBV) infection affects 240 million people worldwide. A liver-specific bile acid transporter named the sodium taurocholate cotransporting polypeptide (NTCP) has been identified as the cellular receptor for HBV and its satellite, the hepatitis D virus (HDV). NTCP likely acts as a major determinant for the liver tropism and species specificity of HBV and HDV at the entry level. NTCP-mediated HBV entry interferes with bile acid transport in cell cultures and has been linked with alterations in bile acid and cholesterol metabolism in vivo. The human liver carcinoma cell line HepG2, complemented with NTCP, now provides a valuable platform for studying the basic biology of the viruses and developing treatments for HBV infection. This review summarizes critical findings regarding NTCP's role as a viral receptor for HBV and HDV and discusses important questions that remain unanswered.

Direct writing of porous tissue scaffolds based on Vaseline-doped hydroxyapatite inks

A novel type of 40 vol.% hydroxyapatite ( HAp ), Ca 10( PO 4)6( OH )2, suspension doped with Vaseline was developed, and porous three-dimensional (3D) scaffolds were fabricated by using a direct ink writing (DIW) method. The preparation of the HAp inks and the principles of the DIW technique were investigated. The microporosity of the scaffold wall increased after introducing the Vaseline, whereas macroporosity can be produced by varying the DIW technique. The micromorphology test results show that the samples sintered at 1150°C for 2 h formed ceramics with a set amount of pores, which benefit cell growth by providing more locations for cells to attach and proliferate. Under a microscope, the proliferations of human liver carcinoma cell line ( HepG2 ) cells can be observed on the 3D HAp scaffolds. The DIW method has the advantages of a rapid process, ease of design and high precision control, potentially inspiring the design and application of biomaterials and scaffolds.

Investigation of cell behaviors on thermo-responsive PNIPAM microgel films

The use of poly(N-isopropylacrylamide) (PNIPAM) as building blocks for engineering responsive coatings and their potential use as switchable substrates such as biosensors have attracted great attention in recent years. However, few studies have been conducted regarding the cell behaviors and the related mechanism on thermos-responsive surfaces consisting of PNIPAM microgel particles. In this work, monodisperse PNIPAM microgels were synthesized and used to prepare PINPAM microgel films. Uniform microgel surfaces can be fabricated by drop-coating with the precoating of a polyethylenimine (PEI) layer. Cell experiments indicate that unlike PNIPAM polymer brushes reported with controllable detachment ability, HepG2, which is a human liver carcinoma cell line, remains adherent on the microgel films upon cooling. Surface plasmon resonance (SPR) experiments show an irreversible adsorption of serum proteins on the microgel surface upon cooling, whose adsorption is a prerequisite of cell adhesion during cell culture. This fact may account for the irreversible adhesion of HepG2 cells.

Design, spectral characterization, thermal, DFT studies and anticancer cell line activities of Co(II), Ni(II) and Cu(II) complexes of Schiff bases derived from 4-amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol

A series of two biologically active Schiff base ligands L1, L2 have been synthesized in equimolar reaction of 4-amino-5-(pyridin-4-yl)-4H-1,2,4-triazole-3-thiol with thiophene-2-carbaldehyde and furan-2-carbaldehyde. The synthesized Schiff bases were used for complexation with different metal ions like Co(II), Ni(II) and Cu(II) by using a molar ratio of ligand: metal as 1:1 and 2:1. The characterization of Schiff bases and metal complexes was done by 1H NMR, UV–Vis, TGA, IR, mass spectrometry and molar conductivity studies. The in DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. On the basis of the spectral studies an octahedral geometry has been assigned for Co(II), Ni(II) and Cu(II) complexes. The effect of these complexes on proliferation of human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (Hep-G2) were studied and compared with those of free ligand. The anticancer cell line results reveal that all metal complexes show moderate to significant % cytotoxicity on cell line HepG2 and MCF-7.

Anticancer Compounds from Chaetomium globosum

The present work resulted in isolation and purification of two potential anticancer compounds from Chaetomium globosum isolated from Egyptian soil. The two compounds were tested against Michigan Cancer Foundation-7(MCF-7) breast cancer cell line and Hepatocellular carcinoma, Human (HEPG-2) a human liver carcinoma cell line and showed inhibition effect on the proliferation of two cell lines. The structures of the two pure compounds were elucidated by HNMR and Mass spectroscopy as methyl 9-dihydro-8-trihydroxy-9-oxo-Hxanthene- 1-carboxylate as a member of xanthones and (E)-methyl 2-hydroxy-6, 6-dimethyl hept-3-enoate.

Synthesis and biological evaluation of new pyridines containing imidazole moiety as antimicrobial and anticancer agents

The synthesis of a novel series of pyridine and bipyridine derivatives is described via one-pot multicomponent reaction of 5-acetylimidazole, malonitrile (or ethylcyanoacetate or diethylmalonate), substituted benzaldehyde (or terephthaldehyde), and ammonium acetate in good yields. The structures of all the new compounds were elucidated on the basis of elemental analysis and spectral data. The antimicrobial activities of the synthesized compounds were screened and the results showed that most of such compounds exhibit considerable activities. Furthermore, some of the newly synthesized compounds were screened for their anticancer activity against human breast cell line (MCF-7) and liver carcinoma cell line (HEPG2) in comparison to doxorubicin. Most of the tested compounds exhibited promising activity.

Schisandra chinensis regulates drug metabolizing enzymes and drug transporters via activation of Nrf2-mediated signaling pathway.

Drug metabolizing enzymes (DMEs) and drug transporters are regulated via epigenetic, transcriptional, posttranscriptional, and translational and posttranslational modifications. Phase I and II DMEs and drug transporters play an important role in the disposition and detoxification of a large number of endogenous and exogenous compounds. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a critical regulator of a variety of important cytoprotective genes that are involved in disposition and detoxification of xenobiotics. Schisandra chinensis (SC) is a commonly used traditional Chinese herbal medicine that has been primarily used to protect the liver because of its potent antioxidative and anti-inflammatory activities. SC can modulate some DMEs and drug transporters, but the underlying mechanisms are unclear. In this study, we aimed to explore the role of Nrf2 in the regulatory effect of SC extract (SCE) on selected DMEs and drug transporters in human hepatocellular liver carcinoma cell line (HepG2) cells. The results showed that SCE, schisandrin A, and schisandrin B significantly increased the expression of NAD(P)H: Nicotinamide Adenine Dinucleotide Phosphate-oxidase or:quinone oxidoreductase 1, heme oxygenase-1, glutamate–cysteine ligase, and glutathione S-transferase A4 at both transcriptional and posttranscriptional levels. Incubation of HepG2 cells with SCE resulted in a significant increase in the intracellular level of glutathione and total glutathione S-transferase content. SCE significantly elevated the messenger ribonucleic acid and protein levels of P-glycoprotein and multidrug resistance-associated protein 2 and 4, whereas the expression of organic anion transporting peptide 1A2 and 1B1 was significantly downregulated by SCE. Knockdown of Nrf2 by small interfering ribonucleic acid attenuated the regulatory effect of SCE on these DMEs and drug transporters. SCE significantly upregulated Nrf2 and promoted the translocation of Nrf2 from cytoplasm to the nuclei. Additionally, SCE significantly suppressed the expression of cytosolic Kelch-like ECH-associated protein 1 (the repressor of Nrf2) and remarkably increased Nrf2 stability in HepG2 cells. Taken together, our findings suggest that the hepatoprotective effects of SCE may be partially ascribed to the modulation of DMEs and drug transporters via Nrf2-mediated signaling pathway. SCE may alter the pharmacokinetics of other coadministered drugs that are substrates of these DMEs and transporters and thus cause unfavorable herb–drug interactions.

Glutathione-Mediated Degradation of Surface-Capped MnO2for Drug Release from Mesoporous Silica Nanoparticles to Cancer Cells

Owing to its higher concentration in cancer cells than that in the corresponding normal cells, glutathione (GSH) provides an effective and flexible mechanism to design drug delivery systems. Here a novel GSH-responsive mesoporous silica nanoparticle (MSN) is reported for controlled drug release. In this system, manganese dioxide (MnO2) nanostructure, formed by the reduction of KMnO4 on the surface of carboxyl-functionalized MSN can block the pores (MSN@MnO2). By a redox reaction, the capped MnO2 nanostructure can dissociate into Mn2+ in the presence of GSH molecules. The blocked pores are then uncapped, which result in the release of the entrapped drugs. As a proof-of-concept, doxorubicin (DOX) as model drug is loaded into MSN@MnO2. DOX-loaded MSN@MnO2 shows an obvious drug release in 10 × 10−3 m GSH, while no release is observed in the absence of GSH. In vitro studies using human hepatocellular liver carcinoma cell line (HepG2) prove that the DOX-loaded MSN@MnO2 can entry into HepG2 cells and efficiently release the loaded DOX, leading to higher cytotoxicity than to that of human normal liver cells (L02). It is believed that further developments of this GSH-responsive drug delivery system will lead to a new generation of nanodevices for intracellular controlled delivery.

Ovothiol isolated from sea urchin oocytes induces autophagy in the Hep-G2 cell line.

Ovothiols are histidine-derived thiols isolated from sea urchin eggs, where they play a key role in the protection of cells toward the oxidative burst associated with fertilization by controlling the cellular redox balance and recycling oxidized glutathione. In this study, we show that treatment of a human liver carcinoma cell line, Hep-G2, with ovothiol A, isolated from Paracentrotus lividus oocytes, results in a decrease of cell proliferation in a dose-dependent manner. The activation of an autophagic process is revealed by phase contrast and fluorescence microscopy, together with the expression of the specific autophagic molecular markers, LC3 II and Beclin-1. The effect of ovothiol is not due to its antioxidant capacity or to hydrogen peroxide generation. The concentration of ovothiol A in the culture media, as monitored by HPLC analysis, decreased by about 24% within 30 min from treatment. The proliferation of normal human embryonic lung cells is not affected by ovothiol A. These results hint at ovothiol as a promising bioactive molecule from marine organisms able to inhibit cell proliferation in cancer cells.