Hepa Lclc7 Cells Research Articles

Phytochemical analysis of the triterpenoids with cytotoxicity and QR inducing properties from the total tea seed saponin of Camellia sinensis

The tea seed triterpene saponin (TS) from Camellia sinensis was found to exhibit better antitumor activity in vivo in S180 implanted ICR mice and QR inducing activity for hepa lclc7 cells respectively compared with the total tea seed saponin (TTS), hydrolysate of the TTS and tea seed flavonoid glycosides (TF). By bioassay-guided isolation, the TS fraction was separated and seven major components were purified and identified as theasaponin E1 (1), theasaponin E2 (2), theasaponin C1 (3), assamsaponin C (4), theasaponin H1 (5), theasaponin A9 (6), and theasaponin A8 (7), among which compounds 4 and 5 were isolated from this genus for the first time. The antitumor bioassay of the isolated compounds showed that compounds 1, 2 and 3 exhibited potential activities against the human tumor cell lines K562 and HL60. Furthermore, compound 1 (the major constituent with a mass content of over 1%) showed significant QR inducing activity with an IR value of 4.2 at 4μg/ml. So it can be concluded that tea seed especially the compound 1 (theasaponin E1) could be used as an antitumor agent and a chemoprevention agent of cancer. The preliminary structure–activity relationship in the anti-tumor activity and QR inducing activity of tea saponins was discussed briefly.

New isoflavonolignan with quinone reductase inducing activity from Alhagi pseudalhagi (M.B.)

Bioassay-directed separation of the chloroform extracts from the air-dried aerial part of Alhagi pseudalhagi (M.B.) led to the isolation of a new isoflavonolignan ( 1), together with five known isoflavones ( 2– 6) (Fig. 1). Their structures were identified on the basis of spectral analysis of NMR, MS, IR, UV and CD spectral evidences. The quinone reductase (QR) inducing activities of the extracts and compound 1 were evaluated and the new isoflavonolignan ( 1) exhibited moderate quinone reductase (QR) inducing activity for hepa lclc7 cells.

Sesquiterpenes with Quinone Reductase-Inducing Activity from Liriodendron Chinense

Bioassay-directed separation of the methylene chloride extracts from the wood of Liriodendron chinense led to the isolation of six sesquiterpenes, tulipinolide (1), alpha-liriodenolide (2), beta-liriodenolide (3), lipiferolide (4), 11,13-dehydrolanuginolide (5), and tulipinolide diepoxide (6). Compounds 1-6 have not been found previously in L. chinense. The structures of the compounds were established on the basis of NMR spectroscopic data. All the compounds exhibited quinone reductase (QR)-inducing activity in Hepa lclc7 cells.

Anthraquinones with Quinone Reductase-Inducing Activity and Benzophenones from Morinda citrifolia (Noni) Roots

Two new benzophenones, morintrifolins A ( 1) and B ( 2), together with 14 known anthraquinones and four other known compounds, were isolated from a chloroform-soluble extract of Morinda citrifolia roots. Of the isolated compounds, four known anthraquinones, namely, 1,2-dihydroxyanthraquinone ( 3), 1,3-dihydroxy-2-methylanthraquinone ( 4), 2-hydroxy-3-(hydroxymethyl)anthraquinone ( 5), and 1,3,6-trihydroxy-2-methylanthraquinone ( 6), exhibited quinone reductase (QR)- inducing activity in Hepa lclc7 cells, with concentrations required to double QR activity of 12.0, 8.1, 0.94, and 0.56 microM, respectively.

Heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli

Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.

Heating decreases epithiospecifier protein activity and increases sulforaphane formation in broccoli

Sulforaphane, an isothiocyanate from broccoli, is one of the most potent food-derived anticarcinogens. This compound is not present in the intact vegetable, rather it is formed from its glucosinolate precursor, glucoraphanin, by the action of myrosinase, a thioglucosidase enzyme, when broccoli tissue is crushed or chewed. However, a number of studies have demonstrated that sulforaphane yield from glucoraphanin is low, and that a non-bioactive nitrile analog, sulforaphane nitrile, is the primary hydrolysis product when plant tissue is crushed at room temperature. Recent evidence suggests that in Arabidopsis, nitrile formation from glucosinolates is controlled by a heat-sensitive protein, epithiospecifier protein (ESP), a non-catalytic cofactor of myrosinase. Our objectives were to examine the effects of heating broccoli florets and sprouts on sulforaphane and sulforaphane nitrile formation, to determine if broccoli contains ESP activity, then to correlate heat-dependent changes in ESP activity, sulforaphane content and bioactivity, as measured by induction of the phase II detoxification enzyme quinone reductase (QR) in cell culture. Heating fresh broccoli florets or broccoli sprouts to 60 °C prior to homogenization simultaneously increased sulforaphane formation and decreased sulforaphane nitrile formation. A significant loss of ESP activity paralleled the decrease in sulforaphane nitrile formation. Heating to 70 °C and above decreased the formation of both products in broccoli florets, but not in broccoli sprouts. The induction of QR in cultured mouse hepatoma Hepa lclc7 cells paralleled increases in sulforaphane formation.

Induction of cytochrome P4501A1 by ozone-oxidized tryptophan in Hepa lclc7 cells.

The present investigation was undertaken to determine whether administration of O3-oxidized amino acids to mouse hepatoma cells, Hepa lclc7 (Hepa-1), in culture would effect Cyp1a1 gene expression. The results demonstrate that, of all the amino acids tested, only O3-oxidized tryptophan caused a significant induction of CYP1A1-dependent 7-ethoxyresorufin O-deethylase (EROD) activity compared to the controls (p < 0.01). CYP1A1 mRNA and protein were markedly induced in the O3-oxidized tryptophan administered group compared to the controls. Gel mobility shift assays using nuclear extracts of Hepa-1 cells revealed that oxidized products of tryptophan can induce both aryl hydrocarbon receptor (AhR) transformation and binding of the liganded AhR complex to its specific DNA recognition site, thereby initiating transcription of the Cyp1a1 gene with concomitant increase of CYP1A1 protein and EROD activity in Hepa-1 cells.

Effects of estradiol and progesterone on cytochrome P4501A1 expression in Hepa 1c1c7 cells.

The effects of estradiol and progesterone on the expression of cytochrome P4501A1 were investigated in Hepa 1c1c7 cells. Both steroids, at 10 microM concentration, increased P4501A1-mediated 7-ethoxyresorufin O-deethyalase activity and amounts of its immunoreactive protein and CYP1A1 mRNA. Gel shift assay revealed that the steroids could induce both AhR transformation and binding of the ligand-AhR complex to its specific DNA recognition site. Transient transfection demonstrated that 5'flanking region of CYP1A1 could respond to the steroid action. The competitive binding assay showed that the steroids bound to AhR with moderate affinity. These results suggested that steroidal structure can be AhR ligands and induce CYP1A1 expression in AhR-dependent manner.

Induction of glutathione S-transferase activity in hepG2 cells by extracts from fruits and vegetables

The human hepatoma cell line, hepG2, retains many of the xenobiotic metabolising enzymes found in normal hepatocytes, including an inducible glutathione S-transferase (GST). The isoform of GST that is induced by xenobiotics in this cell line is GSTA1-1. As a first step to determining the effect of diet on induction of GST in humans, we have examined the ability of extracts from a wide variety of fruits and vegetables to induce GST activity in hepG2 cells. Extracts from cruciferous vegetables (broccoli, Brussels sprouts, cabbage) were the most potent inducers, but this was dependent on the variety. Most of the extracts from fruits, with the exception of grapefruit, were poor inducers. Similarities and differences between the induction of GST and of quinone reductase in mouse hepalclc7 cells are discussed. The results show that extracts from cruciferous vegetables are effective inducers of human GST, in agreement with previous studies on GST in animals and cell lines derived from animals.

Inhibition of Cytochrome P450 1A1 by Antisense Phosphorothioate Oligonucleotide in Hepa lclc7 Cells

The influence of an antisense phosphorothioate oligonucleotide has been investigated on 7-ethoxyresorufin O-deethylase (EROD) activity and CYP1A1 protein in wild type mouse hepatoma Hepa lclc7 (Hepa-1) cells. The results show that administration of a 15-mer antisense phosphorothioate oligonucleotide in ribonucleoside-free minimum essential medium effectively inhibited UV-oxidized tryptophan-inducible EROD activity and CYP1A1 protein. The inhibition of EROD activity was dose- and time-dependent. The inhibition of oxidized tryptophan-inducible EROD activity after administration of 5 μM antisense oligonucleotide for 18 hours was 74% over the control oligonucleotide-administered cells. There was no effect of the control or antisense oligonucleotide on the cell growth. This is the first demonstration that inducible CYP1A1 can be effectively inhibited by antisense phosphorothioate oligonucleotide in Hepa-1 cells. Utility of this approach should be useful in elucidating the role(s) of CYP1A1 in chemical carcinogenesis.

Induction of cytochrome P4501A1 by photooxidized tryptophan in Hepa lclc7 cells

Mouse hepatoma Hepa-lclc? (Hepa-1) cells were cultivated in the presence of UV-irradiated amino acids. The results demonstrated that all of the amino acids tested, UV-oxidized tryptophan caused the highest induction of 7-ethoxyresorufin O-deethylase (EROD) activity compared with the controls (P < 0.01). The induction of EROD activity by oxidized tryptophan was dose dependent, and maximal induction was obtained at 12 hr after administration. Studies with various Hepa-1 mutants, which are defective in either the aryl hydrocarbon (Ah) receptor or Ah receptor nuclear translocator protein, indicated that the induction of EROD activity by oxidized tryptophan occurs through the Ah receptor. Gel mobility shift assays using nuclear extracts of Hepa-1 cells revealed that oxidized products of tryptophan can induce both Ah receptor transformation and binding of the liganded Ah receptor complex to its specific DNA recognition site. CYP1A1 mRNA, quantified by reverse transcription-polymerase chain reaction, and CYP1A1 protein were induced markedly in the oxidized tryptophan group compared with the controls. Injection of isolated oxidized tryptophan products into adult male rats caused significant induction of EROD activity in the pulmonary and hepatic microsomes compared with the controls (P < 0.01). These results demonstrated that oxidized tryptophan induces Ah receptor activation and binding of the liganded Ah receptor complex to its specific DNA recognition site, thereby initiating transcription and translation of the CYP1A1 gene with concomitant increase of EROD activity in Hepa-1 cells. Induction of EROD activity in the liver and lungs after injection of isolated oxidized tryptophan products into rats suggests that a similar mechanism may be operative in vivo.