-
[show abstract]
[hide abstract]
ABSTRACT: Interleukin-1 beta (IL-1β) induces endothelial dysfunction and reduces nitric oxide (NO) production. IL-1β also enhances adhesion molecule expression and induces arteriosclerosis. Conversely, high-density lipoprotein (HDL) induces endothelial NO synthase (eNOS), paraoxonase-1 (PON-1) activity, and maintains vascular health. Diet-derived β-carotene prevents arteriosclerosis, but its mode of action is not understood. The purpose of this study was to examine the HDL-like mechanisms of β-carotene in endothelial cells. We added IL-1β and/or β-carotene to cultured human endothelial cells and examined its effects on the regulation of HDL signal transduction pathways using RT-PCR, real-time PCR, Western blot (WB), and endothelial-U937 adhesion analysis. IL-1β decreased the expression of Ca2+/calmodulin-dependent kinase II (CaMKII), eNOS, PON-1, phosphatidylinositol 3-kinase (PI3K), PSD-95/Dlg/ZO-1 (PZK1), and liver kinase B1 (LKB1). Conversely, it increased the expression of intercellular adhesion molecule-1 (ICAM-1), and monocyte chemoattractant protein 1 (MCP-1). In contrast, β-carotene increased the expression of CaMKKII, PI3K, PZK1, LKB1, eNOS, PON-1, and reduced the expression of ICAM-1 and MCP-1. β-carotene also induced phospho-AMP-activated protein kinase (p-AMPK), phospho-eNOS and PON-1 proteins. Importantly, β-carotene upregulated the IL-1β-mediated decrease of CaMKKII, PZK1, LKB1, eNOS and PON-1. β-carotene inhibited IL-1β-mediated cell adhesion of U937 to endothelial cells. The effect of β-carotene was reversed by a CaMKK inhibitor, STO-609. These findings indicate that β-carotene regulates the expression of PON-1, eNOS and adhesion molecules via CaMKK pathway activation. β-carotene may contribute to the functional maintenance of vascular endothelial cells in a manner similar to HDL, protecting them against stimuli such as IL-1β.
Microvascular Research 06/2012; · 2.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The antibiotic heliquinomycin inhibited cellular DNA replication at IC(50) of 2.5 µM without affecting level of chromatin-bound MCM4 and without activating the DNA replication stress checkpoint system, suggesting that heliquinomycin perturbs DNA replication mainly by inhibiting the activity of replicative DNA helicase that unwinds DNA duplex at replication forks. Among the DNA helicases involved in DNA replication, DNA helicase B was inhibited by heliquinomycin at IC(50) of 4.3 µM and RECQL4 helicase at IC(50) of 14 µM; these values are higher than that of MCM4/6/7 helicase (2.5 µM). These results suggest that heliquinomycin mainly targets actions of the replicative DNA helicases. Gel-retardation experiment indicates that heliquinomycin binds to single-stranded DNA. The single-stranded DNA-binding ability of MCM4/6/7 was affected in the presence of heliquinomycin. The data suggest that heliquinomycin inhibits the DNA helicase activity of MCM4/6/7 complex by stabilizing its interaction with single-stranded DNA.
Journal of biochemistry 02/2012; 151(2):129-37. · 1.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The early stages of vascular endothelial dysfunction enhance angiogenic stimulation and strongly influence vascular rearrangement. The aim of this study was to determine whether a short period of high glucose (HG, 30 mM glucose) plus tumor necrosis factor alpha (TNFα) treatment or reoxygenation after hypoxia (H/R) alters the expression levels of apelin in human endothelial cells. In addition, we also examined the effects of the dietary flavonoid apigenin on apelin expression. Human endothelial cell lines were treated with HG plus TNFα or subjected to H/R. The expression levels of genes and proteins were then assessed by the reverse transcriptase polymerase chain reaction, Western blotting and immunofluorescence analyses. The expression level of apelin was significantly higher in the HG group following exposure to reoxygenation or TNFα. Reoxygenation after hypoxia decreased the expression levels of apelin and fatty acid transport protein (FATP) 1 compared with those observed during hypoxia alone and normoxia in a normal glucose concentration. Inversely, apigenin augmented H/R-reduced apelin and FATP1 expression in endothelial cells. Based on our findings, we propose that the early stages of endothelial disorder subtly influence angiogenesis and that HG and H/R stimulate vascular rearrangement and are involved in fatty acid uptake. Furthermore, dietary apigenin might improve the expression of angiogenic genes and fatty acid uptake.
The Journal of nutritional biochemistry 08/2011; 23(8):929-36. · 4.29 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although hyperglycemia can induce diabetic vascular disorders, the mechanisms responsible for the early stages of this process are unknown. To determine the factor(s) that initially stimulate hyperglycemia and the preventive effects of polyphenols, we examined the effects of high glucose (HG) conditions and several dietary polyphenols on human endothelial cells (EC). The purpose of the present study was to investigate the augmentation of the expression of angiotensin II type I receptor (AT1R), cyclooxygenase-2 (COX-2), lectin-like oxidized LDL receptor-1 (LOX-1), prostacyclin/prostaglandin I 2 synthase (PGIS), and thromboxane A2 synthase (TXA2S) by tumor necrosis factor-alpha (TNFα) in HG conditions (30mM) in human EC over a short period, and we also investigated the regulatory effects of 10 dietary flavonoids. HG plus TNFα strongly induced LOX-1 and AT1R expression in the EC. Furthermore, apigenin, kaempferol, chrysin, and flavone significantly inhibited HG plus TNFα-induced LOX-1 expression. The inhibition of LOX-1 expression by apigenin was found to require a flavone skeleton, the double bond found in its C-ring, and the absence of a third hydroxyl group from its B- and C-rings. These findings suggest that TNFα and HG regulate diverse cellular processes and promote endothelial dysfunction via the expression of LOX-1 and AT1R. Conversely, the inhibitory action of apigenin may be beneficial for the treatment of diabetic endothelial dysfunction.
Microvascular Research 10/2010; 81(1):60-7. · 2.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We examined the possibility that the expression of adhesion molecules is regulated differently in cultured astrocytes from stroke-prone spontaneously hypertensive rats (SHRSP/IZM) rats than in those from Wistar Kyoto rats (WKY/IZM) by tumor necrosis factor-alpha (TNF-alpha) or hypoxia and reoxygenation (H/R) and the inhibitory effects of apigenin. It was found that the expression of vascular cell adhesion molecule-1 (VCAM-1) by TNF-alpha in astrocytes isolated from SHRSP/IZM was increased compared with that in WKY/IZM. The expression of monocyte chemotactic protein-1 (MCP-1) mRNA induced by H/R in SHRSP/IZM astrocytes was increased compared with that in normal oxygen concentrations. Apigenin strongly attenuated TNF-alpha-induced VCAM-1 mRNA and protein expression and suppressed the adhesion of U937 cells and SHRSP/IZM astrocytes. These results suggest that the expression levels of adhesion molecules during H/R affect disease outcome and can drive SHRSP/IZM to stroke. It is suggested that apigenin regulates adhesion molecule expression in reactive astrocytes during ischemia.
Stroke research and treatment. 01/2010; 2010.
-
[show abstract]
[hide abstract]
ABSTRACT: The antibiotic heliquinomycin, which inhibits cellular DNA replication at a half-maximal inhibitory concentration (IC(50)) of 1.4-4 microM, was found to inhibit the DNA helicase activity of the human minichromosome maintenance (MCM) 4/6/7 complex at an IC(50) value of 2.4 microM. In contrast, 14 microM heliquinomycin did not inhibit significantly either the DNA helicase activity of the SV40 T antigen and Werner protein or the oligonucleotide displacement activity of human replication protein A. At IC(50) values of 25 and 6.5 microM, heliquinomycin inhibited the RNA priming and DNA polymerization activities, respectively, of human DNA polymerase-alpha/primase. Thus, of the enzymes studied, the MCM4/6/7 complex was the most sensitive to heliquinomycin; this suggests that MCM helicase is one of the main targets of heliquinomycin in vivo. It was observed that heliquinomycin did not inhibit the ATPase activity of the MCM4/6/7 complex to a great extent in the absence of single-stranded DNA. In contrast, heliquinomycin at an IC(50) value of 5.2 microM inhibited the ATPase activity of the MCM4/6/7 complex in the presence of single-stranded DNA. This suggests that heliquinomycin interferes with the interaction of the MCM4/6/7 complex with single-stranded DNA.
FEBS Journal 06/2009; 276(12):3382-91. · 3.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Diabetes mellitus is associated with increased endothelial dysfunction and development of atherosclerotic vascular diseases. In contrast, an increased intake of dietary flavonoids is associated with a decreased risk of cardiovascular diseases. Here we demonstrate that high glucose (HG) and tumor necrosis factor alpha (TNFalpha) result in the expression of adhesion molecules and junctional molecules on endothelial cells (EC) within a short time. Simultaneously, we examined the regulatory effects of several dietary flavonoids. We demonstrated the short-term expression of adhesion molecules in a human EC line cultured with normal glucose (5.5 mM), HG (30 mM) and TNFalpha (10 ng/ml) by reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry and adhesion assay. The expression of intercellular adhesion molecule-1 (ICAM1) and vascular cell adhesion molecule-1 (VCAM1) increased, but that of occludin decreased. Apigenin strongly inhibited the expression of VCAM1, IkappaB kinase (IKK) alpha and IKKepsilon/IKKi, and suppressed the adhesion of U937 cells. From the structure and inhibitory activity of several dietary flavonoids, it was recognized that a double bond between apigenin and the third hydroxyl group was required for inhibition of gene expression. HG and TNFalpha induced the expression of cell adhesion molecules and reduced that of occludin in EC. These flavonoids modified the expression of cloudin 5 and occludin. These results demonstrated that apigenin inhibits HG- and TNFalpha-induced adhesion molecule expression and that flavonoids regulate the expression of junctional molecules in human EC. It is suggested that apigenin inhibited the expression of several genes through inhibition of IKKs.
The Journal of nutritional biochemistry 03/2009; 21(2):116-24. · 4.29 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Adenosine, which accumulates rapidly during ischemia due to the breakdown of ATP, has beneficial effects in many tissues. We examined whether adenosine induces the production of glial cell line-derived neurotrophic factor (GDNF) in cultured astrocytes. We evaluated GDNF mRNA expression and GDNF production in astrocytes cultured with adenosine and the adenosine selective receptor agonists 5-(N-ethylcarboxamido) adenosine (NECA), N(6)-cyclopentyladenosine (CPA) and 2-p-(2-carboxyethyl) phenethylamino-5'-N-ethylcarboxamindo-adenosine hydrochloride (CGS 21680). Moreover, we examined the possibility that the expression of GDNF is regulated differently in cultured astrocytes from the stroke-prone spontaneously hypertensive rat (SHRSP) than in those from Wistar Kyoto rats (WKY). In this study, we confirmed that adenosine and the selective A(2B) adenosine receptor agonist NECA induced the expression of GDNF in cultured astrocytes. The A(2B) receptor antagonist alloxazine was able to inhibit the increase in extracellular GDNF produced by adenosine. Furthermore, the amounts of GDNF produced were significantly reduced in astrocytes of the adenosine-treated SHRSP compared with those of WKY. These results indicate that adenosine induces the expression of GDNF, and adenosine A(2B) receptors participate in the regulation of GDNF levels in astrocytes. This expression was attenuated in astrocytes of SHRSP compared with those of WKY.
Neuroscience Research 01/2008; 59(4):467-74. · 2.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Five different coloured sweet peppers (Capsicum annuum cv. Signal), white, green, yellow, orange and red were analysed for total carotenoids, α-tocopherol, sugars (glucose, fructose and sucrose), organic acids (citric and ascorbic acids) and anti-oxidant properties. The mature fruits, ‘Signal Red’, ‘Signal Orange’ and ‘Signal Yellow’ contained higher carotenoids, α-tocopherol, sugars and organic acids than the immature fruits, ‘Signal Green’ and ‘Signal White’. Among the mature fruits, ‘Signal Red’ was the highest in total carotenoids [9.15 mg (100 g)−1 of fresh weight] while ‘Signal Orange’ was the highest in α-tocopherol [5.40 mg (100 g)−1 of fresh weight]. ‘Signal Red’ and ‘Signal Orange’ contained the most sugars and organic acids. The suppression of 2,2′-azobis (2,4-dimethylvaleronitrile) (AMVN)-induced oxidation of methyl linoleate by the acetone extracts from the coloured sweet peppers resulted as follows: ‘Signal Red’ > ‘Signal Orange’ ≈ ‘Signal Yellow’ > ‘Signal Green’ ≈ ‘Signal White’. The order of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of the acetone extracts was similar to that of suppression of methyl linoleate oxidation.
International Journal of Food Science & Technology 06/2007; 42(12):1482 - 1488. · 1.26 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The stability of red radish extract to light, heat, and hydrogen peroxide at different pH values (3, 5, and 7) was examined, in which major anthocyanins were pelargonidin glycosides acylated with a combination of p-coumaric, ferulic, or caffeic acids. The light irradiation (fluorescence light, 5000 lx; at 25 degrees C) indicated that the red radish extract was more stable at lower pH than at higher pH. The HPLC analyses revealed that diacylated anthocyanins in the extract were more stable to light at pH 3 than monoacylated anthocyanins. No significant difference in degradation rates of acylated anthocyanins at pH 5 was observed, whereas anthocyanins acylated with p-coumaric or ferulic acids were more stable at pH 7 than ones with caffeic acids. The stability to heat (at 90-95 degrees C) showed a tendency similar to that for light. The number of intramolecular acyl units contributes to stability to light and heat at lower pH, whereas the characteristics of intramolecular acyl units influence the stability at higher pH. The degradation behavior of red radish extract to H2O2 were almost the same to those of light and heat, depending on the pH. However, HPLC analyses revealed that the stability of individual acylated anthocyanins were independent of the pH. These data suggest that the characteristics, the number, and the binding site of intramolecular acyl units affect the stability of anthocyanin to H2O2. DPPH radical scavenging activity of all acylated anthocyanins was higher than those of pelargonidin and perlargonidin-3-glucoside. The activity of acylated anthocyanins mostly depended on the activity of intramolecular acyl units (caffeic acid > ferulic acid > p-coumaric acid). However, the activity was highly affected by the binding site of intramolecular acyl units even if anthocyanins have common acyl units.
Journal of Agricultural and Food Chemistry 05/2007; 55(9):3692-701. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Arsenic compounds in the red alga Porphyra yezoensis were purified by gel filtration on Bio-Gel P-2; chromatographic behavior suggested that they were arsenic-containing ribofuranosides (arsenosugars). When partially purified arsenosugars were orally administered to mice, 86% and 13% of the arsenic administered were excreted in feces and urine, respectively, within 48 h. Arsenic compounds excreted in feces were identified as arsenosugars by gel filtration and highperformance liquid chromatography, while those excreted in urine were identified as methylarsonic acid, dimethylarsinic acid and arsenobetaine. On the other hand, upon intravenous administration of arsenosugars, a large part of the arsenic administered was excreted rapidly in urine; after 72 h, 92% of the arsenic administered was recovered in urine and 6% in feces. Similarly to the case of oral administration, methylarsonic acid, dimethylarsinic acid and arsenobetaine were detected in urine.
Applied Organometallic Chemistry 09/2004; 4(3):281 - 286. · 2.06 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We examined the antioxidant effects of paprika pigments on oxidation of linoleic acid and on decoloration of the sample when stored at 37 degrees C in the dark or exposed to fluorescent light for 8 h per day. (1)H nuclear magnetic resonance with dioxane as an external proton reference was used to estimate the oxidative deterioration of linoleic acid. Oxidation was estimated by observing the ratio of the divinylmethylene proton signal area in linoleic acid vs the proton signal area in dioxane. The addition of paprika pigments suppressed the oxidation of linoleic acid during storage in the dark, and the effect was markedly increased with increasing concentrations (0.02, 0.2, and 2%). When the linoleic acid with added paprika pigments was exposed to light, only a slight suppression of oxidation was observed, and the color of the sample disappeared more rapidly than that in the dark. At the time of decoloration of the sample with added pigments, considerable oxidation of linoleic acid occurred. As the color change is due to degradation of the pigment, an increase in oxidation at the time of discoloration is consistent with the pigments functioning as antioxidants. The addition of alpha-tocopherol to paprika pigments stabilized degradation of the pigments by light. Although the addition of alpha-tocopherol to linoleic acid with added paprika pigments prolonged the decoloration of the sample under light, the prevention of oxidation under the light condition was not as effective as for the samples stored in the dark.
Journal of Agricultural and Food Chemistry 07/2004; 52(11):3601-5. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Six products were formed by reaction of ethynylestradiol (EE2) with sodium hypochlorite in buffered solutions. 4-Chloroethynylestradiol (4-ClEE2) and 2,4-dichloroethynylestradiol (2,4-diClEE2) were identified as the two major reaction products, using preparative HPLC, MS, and NMR. When EE2 reacted with chlorine at different pHs (pH 5, 7, and 9) or chlorine concentrations (0.2, 1, 2, and 5 mmol/l, corresponding to molar ratios to EE2, 1, 5, 10, and 25, respectively), the formation of 4-ClEE2 and 2,4-diClEE2 was observed under the above conditions, and the highest yields were 20 and 52 mol%, respectively. EE2 was consumed almost completely within 5 min of chlorination by addition of chlorine of more than 1 mmol/l (molar ratio to EE2, 5). On the other hand, the two products existed in highly chlorinated solutions after 60 min (4ClEE2, 1-6 mol%; 2,4-diClEE2, 3-25 mol%). The estrogenic activities of 4-ClEE2 by estrogen receptor alpha or beta binding assay were similar to those of the parent EE2, and the activities of 2,4-diClEE2 were lower about 10 times.
Chemosphere 06/2004; 55(6):839-47. · 3.21 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Red radish anthocyanin extract, which consists of 12 known acylated anthocyanins, was reacted with 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) to generate peroxyl radicals under acidic pH conditions at 37 degrees C. The reaction products were isolated using preparative HPLC, and their chemical structures were determined to be p-hydroxybenzoic acid (1), 6-O-(E)-p-coumaroyl-2-O-beta-d- glucopyranosyl-alpha-d-glucopyranoside (3), p-coumaric acid (4), 6-O-(E)-feruloyl-2-O-beta-d-glucopyranosyl-alpha-d-glucopyranoside (5), and ferulic acid (6). Some products were not identified. HPLC analyses of the mixture of acylated pelargonidin isolated from red radish and AAPH revealed that the acylated pelargonidins possess the radical scavenging ability on some common sites even if the characteristics of the intramolecular acyl units are different. Degradation rates of acylated pelargonidins and the formation rates of the resulting reaction products were found to be quite different.
Journal of Agricultural and Food Chemistry 06/2003; 51(10):3157-61. · 2.82 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Three peptide toxins (gigantoxins I-III) with crab toxicity were isolated from the sea anemone Stichodactyla gigantea by gel filtration on Sephadex G-50 and reverse-phase HPLC on TSKgel ODS-120T and their complete amino acid sequences were determined. Gigantoxins II (44 residues) and III (48 residues) have LD(50) (against crabs) of 70 and 120 microg/kg, respectively, and are analogous to the known type 1 and 2 sea anemone sodium channel toxins, respectively. On the other hand, gigantoxin I (48 residues) is potently paralytic to crabs (ED(50) 215 microg/kg), although its lethality is very weak (LD(50)>1000 microg/kg). Interestingly, gigantoxin I has 31-33% homologies with mammalian epidermal growth factors (EGFs), with the same location of six cysteine residues. In accordance with the sequence similarity, gigantoxin I exhibits EGF activity as evidenced by rounding of A431 cells and tyrosine phosphorylation of the EGF receptor in the cells, although much less potently than human EGF. Gigantoxin I is the first example of EGF-like toxins of natural origin.
Toxicon 03/2003; 41(2):229-36. · 2.51 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The antioxidant ability of capsanthin and the fatty acid esters was examined by measuring the free radical-oxidation of methyl linoleate. To assess radical scavenging effect, the production of methyl linoleate hydroperoxides and the decomposition of capsanthins in reaction solution were measured by HPLC. Capsanthin suppressed hydroperoxide formation as well as β-carotene, lutein, and zeaxanthin. Interestingly, capsanthin decomposed more slowly than the other carotenoids, and the radical scavenging effect of capsanthin was found to last longer. Also, the capsanthin esterified partially and/or totally with fatty acids (mono- and/or diesterified capsanthin), isolated from paprika color, suppressed oxidation of methyl linoleate in a similar manner as nonesterified capsanthin. This finding suggests that the radical scavenging ability of capsanthin was not influenced by esterification, that is, the ability would contribute to the polyene chain, especially conjugated keto group. It was first found that esterified (monoesterified and diesterified) capsanthins also were good radical scavengers. Keywords: Capsanthin; esterified capsanthin; esterification; antioxidant activity; radical scavenging ability
09/1998;
-
[show abstract]
[hide abstract]
ABSTRACT: The relationship between the cardiac glycoside contents in Corchorus olitorius seeds and the seed color was examined. The seed color was assigned a shade (color value) (L value in UCS system). The dark grayish green seeds, showing lower L value, contained more cardiac glycosides than dark grayish yellow seeds showing higher L value. When the total cardiac glycoside contents were plotted against the L values, a positive correlation (r = –0.913) was observed. Also, there was a higher content ratio of strophanthidin glycosides (erysimoside and olitoriside) in the seeds showing lower L value, while there was a lower content ratio of digitoxigenin glycosides (coroloside and glucoevatromonoside) in the seeds showing lower L value.
Journal of Health Science. 478510:158-8501.
