BACKGROUND: Rice bran is the outer layer of the rice grain, and contains high amounts of bioactive phytochemicals. Here, we investigated and compared chemopreventive properties of purple and white rice bran extracts. METHODS: Rice bran was extracted with dichloromethane and methanol. Chemical constituents in the extracts were analyzed by colorimetric assay and high performance liquid chromatography. The mutagenicity and antimutagenicity of the extracts were determined via the Salmonella mutation assay. The anticarcinogenic enzyme induction and antioxidant activities of the extracts were examined using Hepa1c1c7 cells and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, respectively. RESULTS: The methanol extracts of rice bran contained high amounts of phenolic acids, flavonoids, anthocyanins, and phytic acid, whereas large amounts of γ-oryzanol and vitamin E were presented in the dichloromethane extract. None of the extracts were mutagenic to Salmonella typhimurium. All rice bran extracts had strong antimutagenic effects against aflatoxin B1- and 2-amino-3,4-dimethylimidazo [4,5-f]quinoline-induced mutagenesis. The inhibitory effect against 2-aminofluorene-induced mutagenesis was found in the dichloromethane extract, while only the methanol extract of purple rice bran exhibited antimutagenic effects against benzo(a)pyrene. None of the extracts induced quinone reductase activity in Hepa1c1c7 cells. Additionally, the greatest antioxidant capacity was found in the methanol extract of purple rice bran. CONCLUSIONS: The methanol extract of purple rice bran containing high amount of phenolic acids, flavonoids, anthocyanins, and phytic acid showed the most effective antioxidant and antimutagenic activities by inhibiting mutagenic metabolizing enzymes and/or scavenging free radicals. These results demonstrate the nutritional and medical value of Thai rice for cancer prevention.
Aflatoxins ; Anthocyanins ; Antimutagenic Agents ; Asian Continental Ancestry Group* ; Benzo(a)pyrene ; Chromatography, Liquid ; Enzyme Induction ; Flavonoids ; Free Radicals ; Humans ; Methanol ; Methylene Chloride ; Mutagenesis ; NAD(P)H Dehydrogenase (Quinone) ; Phenol ; Phytic Acid ; Phytochemicals ; Salmonella ; Salmonella typhimurium ; Vitamin E ; Vitamins

<p>OBJECTIVETo explore a new method of establishing HepG2 cell model of steatosis and observe the expression and significance of nuclear factor erythroid-2p45-related factor 2(Nrf2)/antioxidative response element (ARE) pathway related factors in HepG2 cells of steatosis.p><p>METHODSHepG2 cells were induced with DMEM containing 25% fetal bovine serum, 0.1% MCT/LCT Fat Emulsion and 0.1 mmol/L free fatty acid (FFA) at different stages and the control group cells were cultured with normal DMEM medium. After the cell models were successfully established, lipid droplets in cytoplasm were observed with Oil Red 0 staining, and the triglyceride (TG) accumulation in HepG2 cells were tested by biochemical assay. Intracellular reactive oxygen species (ROS) concentration were detected by flow cytometry. Nitric oxide (NO), superoxide dismutase(SOD), malonyldialdehyde(MDA) and glutathione peroxidase(GSH-Px) were tested by biological reagent kit, while the protein expression of nuclear factor erythroid-2p45-related factor 2(Nrf2), heme oxygenase-1 (HO-1) andp><p>NAD(P)Hquinone oxidoreductase-1(NQO1) were analyzed by Western blot.p><p>RESULTSCompared with that in the control group, red cytoplasmic lipid droplets were visible in model group; TG,ROS, NO, MDA concentration (P < 0.05, P < 0.01) and the protein expression of Nrf2, HO-1 and NQO1 (P < 0.05, P < 0.01)were significantly higher in model group, while SOD, GSH-Px concentration reduced significantly (P < 0.01).p><p>CONCLUSIONThe in vitro cell model of steatosis and oxidative stress was successfully established. The activation of Nrf2/ARE pathway related factors maybe relevant to the overreaction of oxidative stress in HepG2 cells of steatosis.p>
Antioxidant Response Elements ; Culture Media ; Fatty Acids, Nonesterified ; Fatty Liver ; metabolism ; GA-Binding Protein Transcription Factor ; Glutathione Peroxidase ; metabolism ; Heme Oxygenase-1 ; metabolism ; Hep G2 Cells ; Humans ; Malondialdehyde ; metabolism ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NF-E2-Related Factor 2 ; metabolism ; Nitric Oxide ; metabolism ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism ; Triglycerides ; metabolism

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the first rate-limiting step in converting nicotinamide to NAD(+), essential for a number of enzymes and regulatory proteins involved in a variety of cellular processes, including deacetylation enzyme SIRT1 which modulates several tumor suppressors such as p53 and FOXO. Herein we report that NQO1 substrates Tanshione IIA (TSA) and β-lapachone (β-lap) induced a rapid depletion of NAD(+) pool but adaptively a significant upregulation of NAMPT. NAMPT inhibition by FK866 at a nontoxic dose significantly enhanced NQO1-targeting agent-induced apoptotic cell death. Compared with TSA or β-lap treatment alone, co-treatment with FK866 induced a more dramatic depletion of NAD(+), repression of SIRT1 activity, and thereby the increased accumulation of acetylated FOXO1 and the activation of apoptotic pathway. In conclusion, the results from the present study support that NAMPT inhibition can synergize with NQO1 activation to induce apoptotic cell death, thereby providing a new rationale for the development of combinative therapeutic drugs in combating non-small lung cancer.
Abietanes ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; enzymology ; genetics ; physiopathology ; Cell Line, Tumor ; Cytokines ; antagonists & inhibitors ; genetics ; metabolism ; Enzyme Inhibitors ; pharmacology ; Humans ; NAD ; metabolism ; NAD(P)H Dehydrogenase (Quinone) ; genetics ; metabolism ; Naphthoquinones ; pharmacology ; Nicotinamide Phosphoribosyltransferase ; antagonists & inhibitors ; genetics ; metabolism

The role of genetic polymorphisms of NAD(P)H:quinone oxidoreductase 1 (NQO1), which is known to be related to carcinogen metabolism and oxidative status, was evaluated for lung cancer development. The genotypes of two NQO1 polymorphisms, namely, IVS1-27C>G and Ex6+40C>T, were determined in 616 lung cancer cases and 616 lung cancer-free controls and haplotypes composed of the two polymorphisms were estimated. In the evaluation of the effect of the NQO1 genotypes or diplotypes, we did not find any significant association with lung cancer risk after adjusting for body mass index and smoking status. However, when we evaluated the effect of the NQO1 diplotypes for lung cancer risk in combination with smoking, smokers without the C-T/C-T diplotype showed a significantly increased risk of lung cancer compared with nonsmokers without the C-T/C-T diplotype (adjusted OR, 2.2; 95% CI, 1.67-3.02), and smokers with the C-T/C-T diplotype showed the highest OR of lung cancer (adjusted OR, 2.7; 95% CI, 1.78-4.21). Moreover, a trend test showed an additive interaction between smoking and the NQO1 C-T/C-T diplotype (P(trend) < 0.01). The additive effect of smoking and the NQO1 C-T/C-T diplotype was more apparent in squamous cell carcinoma, although this effect was statistically significant in all lung cancer cell types (all cell types, P(trend) < 0.05). This result suggests that haplotypes of the NQO1 gene play an important role in the development of lung cancer by interaction with smoking.
Aged ; Carcinoma, Non-Small-Cell Lung/epidemiology/*genetics ; Female ; Genetic Predisposition to Disease ; Haplotypes/genetics ; Humans ; Lung Neoplasms/epidemiology/*genetics ; Male ; Middle Aged ; NAD(P)H Dehydrogenase (Quinone)/*genetics ; Polymorphism, Single Nucleotide/genetics ; Risk ; Small Cell Lung Carcinoma/epidemiology/*genetics ; Smoking/*adverse effects

Carcinoma, Medullary ; metabolism ; Carcinoma, Neuroendocrine ; Humans ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NADP ; metabolism ; Neoplasm Proteins ; metabolism ; Prognosis ; Thyroid Neoplasms ; metabolism

<p>OBJECTIVETo investigate the regulation of α-Tocopherol on NFκB and Nrf2 signaling pathway at early stage of N-nitrosomethylbenzylamine (NMBzA)-induced human esophageal carcinogenesis.p><p>METHODSHuman normal esophageal HET-1A cells were treated with NMBzA at 50 µmol/L, 100 µmol/L for 24 h to intimate the initiation of esophageal carcinogenesis. For intervention groups, HET-1A cells were pre-treated with α-T at 25, 50, 100 µmol/L for 3 h and then co-treated with NMBzA (100 µmol/L) for 24 h. In comparison with HET-1A cells, human esophageal cancer EC109 cells were treated with α-T at corresponding concentrations. Cells treated with 0.1% DMSO were used as negative control. Immunofluorence staining was used for the determination of distribution and activation of NFκB p65 and Nrf2 in the cell. Real time PCR and Western blot were used to determine the expression levels of target genes including cyclinD1, KI67, proliferating cell nuclear antigen (PCNA), cyclo-oxygen-ase 2 (COX2), 5LOX, HO-1, NQO1 and GCLC. Flow cytometry was utilized to analyze the reactive oxygen species contents in the cells.p><p>RESULTSAs compared to the control group (1.00 ± 0.08), the expression of CyclinD1 (2.99 ± 0.15), KI67 (2.35 ± 0.38) and PCNA (2.46 ± 0.25) in HET-1A were all markedly increased by NMBzA treatment (F values were 97.23, 65.28, 34.62, P < 0.001). Also, the proportion of cells with nucleus translocation of NFκB p65 (71.0%, 98/138) or Nrf2 (36.3%, 49/135) were significantly increased (χ² values were 194.71, 133.72, P < 0.001), and the expression of COX2 (3.22 ± 0.17), 5LOX (2.87 ± 0.12) as well as HO-1 (1.87 ± 0.22), NQO1 (2.14 ± 0.08), GCLC (2.63 ± 0.41) at protein levels were elevated (F values were 72.35, 43.87, 69.23, 71.34, 85.79, P values were 0.013, 0.015, 0.010, 0.011, 0.002). Under the treatment with 50 µmol/L α-T, comparing with the control group(59.1%,65/110),the nuclear translocation of NFκB p65 (77.7%, 8/104) was clearly inhibited (χ² = 148.1, P < 0.001), and protein expression levels of COX2 (0.74 ± 0.19) and 5LOX (0.42 ± 0.13) were decreased (F values were 56.31, 73.25, P values were 0.003, 0.001). However, no changes on Nrf2 signaling pathway were observed; α-T showed little impact on NFκB or Nrf2 pathway in EC109 cells.p><p>CONCLUSIONSAt the early stage of NMBz-induced esophageal cancer, α-T could block the initiation of carcinogenesis through suppressing the activation of NFκB signaling pathway. It might be the major mechanism by which α-T is potentially chemopreventive to esophageal cancer. During the progression of esophageal cancer, the cells may acquire the adaptive functions to accommodate oxidative stress via activating Nrf2 pathway.p>
Carcinogenesis ; Cyclooxygenase 2 ; Dimethylnitrosamine ; analogs & derivatives ; Esophageal Neoplasms ; Heme Oxygenase-1 ; Humans ; NAD(P)H Dehydrogenase (Quinone) ; NF-E2-Related Factor 2 ; NF-kappa B ; Oxidative Stress ; Reactive Oxygen Species ; Signal Transduction ; alpha-Tocopherol

Hypoxia, a state of low oxygen, is a common feature of solid tumors and is associated with disease progression as well as resistance to radiotherapy and certain chemotherapeutic drugs. Hypoxic regions in tumors, therefore, represent attractive targets for cancer therapy. To date, five distinct classes of bioreactive prodrugs have been developed to target hypoxic cells in solid tumors. These hypoxia-activated prodrugs, including nitro compounds, N-oxides, quinones, and metal complexes, generally share a common mechanism of activation whereby they are reduced by intracellular oxidoreductases in an oxygen-sensitive manner to form cytotoxins. Several examples including PR-104, TH-302, and EO9 are currently undergoing phase II and phase III clinical evaluation. In this review, we discuss the nature of tumor hypoxia as a therapeutic target, focusing on the development of bioreductive prodrugs. We also describe the current knowledge of how each prodrug class is activated and detail the clinical progress of leading examples.
Anthraquinones ; chemistry ; pharmacology ; Antineoplastic Agents ; chemistry ; pharmacology ; Aziridines ; chemistry ; pharmacology ; Cell Hypoxia ; drug effects ; Humans ; Indolequinones ; chemistry ; pharmacology ; Molecular Structure ; NAD(P)H Dehydrogenase (Quinone) ; chemistry ; pharmacology ; Neoplasms ; drug therapy ; pathology ; Nitrogen Mustard Compounds ; chemistry ; pharmacology ; Nitroimidazoles ; chemistry ; pharmacology ; Phosphoramide Mustards ; chemistry ; pharmacology ; Prodrugs ; chemistry ; pharmacology ; Triazines ; chemistry ; pharmacology

<p>OBJECTIVETo measure the levels of ghrelin-induced expression or activation of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), andp><p>NAD(P)Hquinone oxidoreductase 1 (NQO1) in the PQ-injured lungs of mice and to evaluate the protective effect of ghrelin against paraquat (PQ)-induced acute lung injury in mice.p><p>METHODSAccording to the random number table method, 50 ICR mice of clean grade were assigned to 5 groups: normal control group (n = 10), PQ group (n = 10), and ghrelin intervention groups (n = 30). For PQ group, mice were injected with a single dose of PQ (20 mg/kg, i.p.); for ghrelin intervention groups, mice were injected with a single dose of PQ (20 mg/kg, i.p.), and then ghrelin was injected at three concentrations (16.58, 33.15, and 49.73 µg/kg). Lung tissues were collected and proceeded to the following studies. HE staining was used for histopathological examination under a light microscope, and the changes in nuclear expression of Nrf2 were evaluated by Western blot. The activities of HO-1 and NQO1 were measured by ELISA. Malondialdehyde (MDA) content and MPO activity were measured by colorimetry. Another 40 mice were divided into PQ group (n = 10) and 16.58, 33.15, and 49.73 µg/kg ghrelin intervention groups (n = 10 for each); mortality and clinical manifestations were recorded within 72 h.p><p>RESULTSCompared with the normal control group, the PQ group showed significant increases in nuclear protein level of Nrf2, content of MDA, and activities of HO-1, NQO1, and MPO (P < 0.05 for all). Compared with the PQ group, ghrelin treatment significantly increased the expression of Nrf2 and activities of HO-1 and NQO1 and significantly reduced the content of MDA and activity of MPO (P < 0.01 for all). Histopathological studies indicated that ghrelin showed an antioxidant property that reduced the histological changes induced by PQ in the lungs. The ghrelin intervention groups had a significantly lower mortality than the PQ group, and there was a significant difference between the high-dose ghrelin intervention group and PQ group (P < 0.05).p><p>CONCLUSIONGhrelin can up-regulate nuclear expression of Nrf2, increase the activities of HO-1 and NQO1, and reduce the activity of MPO and content of MDA, thus protecting PQ-exposed mice from acute lung injury.p>
Acute Lung Injury ; chemically induced ; metabolism ; Animals ; Ghrelin ; pharmacology ; Heme Oxygenase-1 ; metabolism ; Lung ; drug effects ; metabolism ; Male ; Malondialdehyde ; metabolism ; Membrane Proteins ; metabolism ; Mice ; Mice, Inbred ICR ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NF-E2-Related Factor 2 ; metabolism ; Oxidative Stress ; Paraquat ; poisoning ; Peroxidase ; metabolism

<p>OBJECTIVETo explore the role of NF-E2-related factor 2(Nrf2) and its related factors in the progression of nonalcoholi steatohepatitis (NASH) by investigating the alterations of lipid metabolism and liver histopathology as well as the changes of mRNA and protein expression levels of Nrf2 and its related factors in rats during NASH progression.p><p>METHODSMale SD rats were randomly divided into normal group and model group, which were administrated with high fat diet to establish nonalcoholic steatohepatitis model. The rats from both groups were randomly killed at the end of 4, 12 weeks respectively. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) were detected in the serum and liver tissue; Changes in fat deposition in liver tissue were determined by oil red O staining. HE staining were used to observe the pathological changes of liver tissue and to calculate nonalcoholic fatty liver disease (NAFLD) activity score (hepatic steatosis, inflammation and ballooning degeneration of liver cells). The expression of Nrf2 in liver was detected by immunohistochemical staining. The mRNA and protein levels of Nrf2 and related factors in liver were determined by Realtime PCR and Western blot, respectively.p><p>RESULTSAfter 4 weeks of high fat diet, the levels of ALT, AST, TC in rat serum and TC, TG, LDL-C in liver were significantly increased compared with that of the normal group (P < 0.01, P < 0.05). After 4 weeks of high fat diet, the levels of ALT, AST, TC, TG in serum and TC, TG, LDL- C in liver increased further (P < 0.01, P < 0.05). Until the 12th week, the content of HDL-C in liver was significantly lower than that of the normal group (P < 0.05). At the end of the 4th or the 12th week, lipid droplets in the model rat liver cells were heavily dyed red and hepatic steatosis increased severely, with ballooning degeneration of liver cells. With the extension of high fat diet feeding time, fat deposition in the liver tissue, hepatic steatosis, NAFLD score, Nrl2 expression were significantly increased (P < 0.01). Expression levels of mRNA and protein of Nrf2, heme oxyenase 1(HO1), NADPH quinone oxidoreductase 1(NQO1), γ-glutamylcysteine synthethase (γ-GCS), glutathione S-transferase (GST) in the model rats increased or decreased at the end of the 4th or the 12th week differentially, (P < 0.01, P < 0.05) with the more significant changes at the end of the 4th week than the 12th week.p><p>CONCLUSIONNrf2 and its related factors may be involved in the occurrence and development of nonalcoholic fatty liver disease, which may play an important role in the process of NASH formation.p>
Alanine Transaminase ; metabolism ; Animals ; Aspartate Aminotransferases ; metabolism ; Cholesterol ; metabolism ; Diet, High-Fat ; Dipeptides ; metabolism ; Disease Progression ; Glutathione Transferase ; metabolism ; Heme Oxygenase (Decyclizing) ; metabolism ; Lipid Metabolism ; Liver ; pathology ; Male ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NF-E2-Related Factor 2 ; metabolism ; Non-alcoholic Fatty Liver Disease ; metabolism ; Rats ; Rats, Sprague-Dawley ; Triglycerides ; metabolism

<p>OBJECTIVETo investigate the significance of NADPH quinine oxidoreductase 1 (NQO1) protein overexpression on prognostic evaluation of head and neck squamous cell carcinoma (HNSCC).p><p>METHODSNQO1 protein was detected in 162 of HNSCC, 45 cases of adjacent nontumor tissues and 26 samples of normal head and neck epithelia using EnVision immunohistochemical. Correlation between NQO1 overexpression and patients prognosis was also analyzed.p><p>RESULTSThe positive rate and strongly positive rate of NQO1 protein were 84.0% (136/162) and 69.8% (113/162) in HNSCC, respectively, and both of which were significantly higher than either those in adjacent nontumor tissues and normal head and neck epithelia (both P < 0.01). NQO1 expression was significantly correlated with the clinical stage, pT and chemoradiotherapy of HNSCC (P < 0.01). Kaplan-Meier survival analysis showed that overall survival and disease-free survival rates were significantly higher in HNSCC patients with high level NQO1 expression than that those with low level of NQO1 expression (Log-rank = 6.625 , P = 0.010;Log-rank = 6.234 , P = 0.013). Additional analysis by Cox proportional hazard regression model showed that high level of NQO1 expression was an independent hazard predictor for overall survival of patients with HNSCC (Wald = 6.626, P = 0.008).p><p>CONCLUSIONSNQO1 expression level is closely correlated with the progression and prognosis of patients with HNSCC. High level of NQO1 expression may be used as an important indicator for patients with poor prognostic HNSCC.p>
Breast ; enzymology ; Carcinoma, Squamous Cell ; enzymology ; mortality ; pathology ; Disease-Free Survival ; Female ; Head and Neck Neoplasms ; enzymology ; mortality ; pathology ; Humans ; Kaplan-Meier Estimate ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NADH, NADPH Oxidoreductases ; metabolism ; Prognosis ; Proportional Hazards Models