Biofactors - Volume 20, issue 1

Authors: Kutuk, Ozgur | Adli, Mazhar | Poli, Giuseppe | Basaga, Huveyda

Article Type: Research Article

Abstract: Here we report on the marked protective effect of resveratrol on 4-hydroxynonenal (4-HNE) induced oxidative stress and apoptotic death in Swiss 3T3 fibroblasts. 4-HNE, one of the major aldehydic products of the peroxidation of membrane w-6 polyunsaturated fatty acids, has been suggested to contribute to oxidant stress mediated cell injury. Indeed, in vitro treatment of 3T3 fibroblasts with 4-HNE induced a condition of oxidative stress as monitored by the oxidation of dichlorofluorescein diacetate; this reaction was …prevented when cells were pretreated with resveratrol. Further, 4-HNE-treated fibroblasts eventually underwent apoptotic death as determined by differential staining and internucleosomal DNA fragmentation. Resveratrol pretreatment also prevented 4-HNE induced DNA fragmentation and apoptosis. These observations are consistent with a potential role of lipid peroxidation-derived products in programmed cell death and demonstrate that resveratrol can counteract this effect by quenching cell oxidative stress. Show more

Keywords: 4-HNE, lipid peroxidation, cell death, resveratrol, DNA fragmentation

Citation: BioFactors, vol. 20, no. 1, pp. 1-10, 2004

Authors: Han, Dalho | Nagy, Scott R. | Denison, Michael S.

Article Type: Research Article

Abstract: In this study, we have compared the time and dose response curves for TCDD using the pGudLuc1.1-chemically activated luciferase expression (CALUX) cell bioassay and two new recombinant cell lines that contain a stably transfected mutated form of firefly luciferase reporter gene (pGudLuc6.1) or enhanced green fluorescent protein (EGFP) reporter gene (pGreen1.1). The time course of induction with pGudLuc1.1-containing H1L1.1c2 cells is transient, with maximal activity observed at 4 hours after treatment with 1 nM TCDD. In …contrast, expression of luciferase from the pGudLuc6.1-containing H1L6.1c2 cells and the pGreen1.1-containing H1G1.1c3 cells progressively increases with time, with luciferase activity increasing at a significant faster rate than that of EGFP. Dose response analysis with each cell line at optimal analysis times reveal similar relative dose response curves and EC_{50} s for H1L6.1c2 and H1G1.1c3 cells, while the EC_{50} for TCDD in the H1L1.1c2 cells was about 7-fold lower. In addition, these bioassay systems respond to halogenated and/or polycyclic aromatic hydrocarbons in a dose-specific manner. Given the above differences between cell lines and reporters, the choice of which cell line to use will certainly be dependent on the specific questions and issues being examined. Show more

Keywords: cell bioassay, Ah receptor agonists, TCDD, CALUX, EGFP

Citation: BioFactors, vol. 20, no. 1, pp. 11-22, 2004

Authors: Hurst, John S. | Contreras, Janice E. | Siems, Werner G. | van Kuijk, Frederik J.G.M.

Article Type: Research Article

Abstract: The stability to autoxidation of the polar carotenoids, lutein and zeaxanthin, was compared to that of the less polar carotenoids, β-carotene and lycopene at physiologically or pathophysiologically relevant concentrations of 2 and 6 μM, after exposure to heat or cigarette smoke. Three methodological approaches were used: 1) Carotenoids dissolved in solvents with different polarities were incubated at 37 and 80°C for different times. 2) Human plasma samples were subjected to the same temperature conditions. 3) …Methanolic carotenoid solutions and plasma were also exposed to whole tobacco smoke from 1–5 unfiltered cigarettes. The concentrations of individual carotenoids in different solvents were determined spectrophotometrically. Carotenoids from plasma were extracted and analyzed using high performance liquid chromatography. Carotenoids were generally more stable at 37 than at 80°C. In methanol and dichloromethane the thermal degradation of β-carotene and lycopene was faster than that of lutein and zeaxanthin. However, in tetrahydrofuran β-carotene and zeaxanthin degraded faster than lycopene and lutein. Plasma carotenoid levels at 37°C did not change, but decreased at 80°C. The decrease of β-carotene and lycopene levels was higher than those for lutein and zeaxanthin. Also in the tobacco smoke experiments the highest autoxidation rates were found for β-carotene and lycopene at 2 μM, but at 6 μM lutein and zeaxanthin depleted to the same extent as β-carotene. These data support our previous studies suggesting that oxidative stress degrade β-carotene and lycopene faster than lutein and zeaxanthin. The only exception was the thermal degradation of carotenoids solubilized in tetrahydrofuran, which favors faster breakdown of β-carotene and zeaxanthin. Show more

Keywords: autoxidation, β-carotene, carotenoids, cigarette smoke; heat, lutein, lycopene, zeaxanthin

Citation: BioFactors, vol. 20, no. 1, pp. 23-35, 2004

Authors: Imamoto, Eiko | Yoshida, Norimasa | Uchiyama, Kazuhiko | Kuroda, Masaaki | Kokura, Satoshi | Ichikawa, Hiroshi | Naito, Yuji | Tanigawa, Toru | Yoshikawa, Toshikazu

Article Type: Research Article

Abstract: The interaction between leukocytes and the vascular endothelial cells (EC) via cellular adhesion molecules plays an important role in various inflammatory and immune diseases. It has been suggested that peroxisome proliferator-activated receptor-γ (PPAR-γ, a member of the nuclear receptor superfamily of transcription factors) might be involved in the control of inflammation and in modulating the expression of various cytokines. The aim of this investigation was to evaluate the anti-inflammatory properties of …PPAR-γ activators, as well as the inhibitory effect of PPAR-γ on the expression of adhesion molecules on leukocytes and vascular endothelial cells. Pioglitazone, a synthetic PPAR-γ activator, suppressed the increase of CD11b/CD18 expression on FMLP-activated leukocytes, as detected by immunofluorescence flow cytometry. However, the FMLP-induced elevation of cytosolic Ca^{2+} in leukocytes was not suppressed by pioglitazone. Pioglitazone inhibited the expression of VCAM-1 protein and mRNA on activated human umbilical vein endothelial cells (HUVEC) after IL-1β stimulation, as detected by ELISA and real-time PCR. However, it showed little effect on the expression of ICAM-1 and E-selectin. The present study revealed that pioglitazone can influence monocyte-EC binding by inhibiting VCAM-1 expression on activated EC and neutrophil-EC binding by inhibiting upregulation of CD11b/CD18 on activated neutrophils. Accordingly, pioglitazone may be useful for treating inflammatory diseases. Show more

Keywords: pioglitazone, adhesion molecule, neutrophils, endothelial cells

Citation: BioFactors, vol. 20, no. 1, pp. 37-47, 2004

Authors: Naito, Yuji | Uchiyama, Kazuhiko | Aoi, Wataru | Hasegawa, Goji | Nakamura, Naoto | Yoshida, Norimasa | Maoka, Takashi | Takahashi, Jiro | Yoshikawa, Toshikazu

Article Type: Research Article

Abstract: Oxidative stress is implicated as an important mechanism by which diabetes causes nephropathy. Astaxanthin, which is found as a common pigment in algae, fish, and birds, is a carotenoid with significant potential for antioxidative activity. In this study, we examined whether chronic administration of astaxanthin could prevent the progression of diabetic nephropathy induced by oxidative stress in mice. We used female db/db mice, a rodent model of type 2 diabetes, and their non-diabetic db/m littermates. The …mice were divided into three groups as follows: non-diabetic db/m, diabetic db/db, and diabetic db/db treated with astaxanthin. Blood glucose level, body weight, urinary albumin, and urinary 8-hydroxydeoxyguanosine (8-OHdG) were measured during the experiments. Histological and 8-OHdG immunohistochemical studies were performed for 12 weeks from the beginning of treatment. After 12 weeks of treatment, the astaxanthin-treated group showed a lower level of blood glucose compared with the non-treated db/db group; however, both groups had a significantly high level compared with the db/m mice. The relative mesangial area calculated by the mesangial area/total glomerular area ratio was significantly ameliorated in the astaxanthin-treated group compared with the non-treated db/db group. The increases in urinary albumin and 8-OHdG at 12 weeks of treatment were significantly inhibited by chronic treatment with astaxanthin. The 8-OHdG immunoreactive cells in glomeruli of non-treated db/db mice were more numerous than in the astaxanthin-treated db/db mice. In this study, treatment with astaxanthin ameliorated the progression and acceleration of diabetic nephropathy in the rodent model of type 2 diabetes. The results suggested that the antioxidative activity of astaxanthin reduced the oxidative stress on the kidneys and prevented renal cell damage. In conclusion, administration of astaxanthin might be a novel approach for the prevention of diabetes nephropathy. Show more

Keywords: astaxanthin, diabetic nephropathy, 8-hydroxydeoxyguanosine, oxidative stress

Citation: BioFactors, vol. 20, no. 1, pp. 49-59, 2004