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1.
Nature ; 562(7725): 86-90, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30224747

RESUMO

Topological operations around exceptional points1-8-time-varying system configurations associated with non-Hermitian singularities-have been proposed as a robust approach to achieving far-reaching open-system dynamics, as demonstrated in highly dissipative microwave transmission3 and cryogenic optomechanical oscillator4 experiments. In stark contrast to conventional systems based on closed-system Hermitian dynamics, environmental interferences at exceptional points are dynamically engaged with their internal coupling properties to create rotational stimuli in fictitious-parameter domains, resulting in chiral systems that exhibit various anomalous physical phenomena9-16. To achieve new wave properties and concomitant device architectures to control them, realizations of such systems in application-abundant technological areas, including communications and signal processing systems, are the next step. However, it is currently unclear whether non-Hermitian interaction schemes can be configured in robust technological platforms for further device engineering. Here we experimentally demonstrate a robust silicon photonic structure with photonic modes that transmit through time-asymmetric loops around an exceptional point in the optical domain. The proposed structure consists of two coupled silicon-channel waveguides and a slab-waveguide leakage-radiation sink that precisely control the required non-Hermitian Hamiltonian experienced by the photonic modes. The fabricated devices generate time-asymmetric light transmission over an extremely broad spectral band covering the entire optical telecommunications window (wavelengths between 1.26 and 1.675 micrometres). Thus, we take a step towards broadband on-chip optical devices based on non-Hermitian topological dynamics by using a semiconductor platform with controllable optoelectronic properties, and towards several potential practical applications, such as on-chip optical isolators and non-reciprocal mode converters. Our results further suggest the technological relevance of non-Hermitian wave dynamics in various other branches of physics, such as acoustics, condensed-matter physics and quantum mechanics.

2.
Phys Rev Lett ; 127(8): 083601, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34477430

RESUMO

Anti-parity-time (APT) symmetry is associated with various effects beyond the fundamental limitations implied in the standard Hermitian-Hamiltonian dynamics. Here, we create an optical APT-symmetric system in a synthetic frequency domain using a conventional fiber without intrinsic gain or loss and experimentally reveal photonic APT-symmetric effects, including energy-difference conservation and synchronized power oscillation, which have not yet been confirmed experimentally in the optical domain. The optical fiber-based APT-symmetric system has a long interaction length because of its negligible loss, and the APT-symmetric Hamiltonian is precisely tunable with optical pumping density and phase mismatch. On this basis, we observe the phase transition at exceptional points, energy-difference conservation, and synchronized power oscillation. Our results provide a robust theoretical and experimental framework connecting the emerging non-Hermitian physics with technologically important nonlinear fiber-optic interactions.

3.
Nanotechnology ; 30(5): 054003, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30511659

RESUMO

In last few decades, micro- and nano-fabrication techniques based on photolithography and electron beam lithography have advanced greatly, mainly in the field of semiconductor fabrication. Such techniques are generally transferrable to the fabrication of plasmonic structures and metamaterials. However, plasmonic devices often require a transparent insulating substrate to be operational at visible or near-infrared wavelengths. Here we report a resist-on-metal bilayer lift-off technique enabling the fabrication of plasmonic structures on insulating substrates. The metal layer under the resist eliminates major difficulties in lithography, such as charging during electron beam exposure and uncontrolled diffuse optical scattering during photolithography. In addition, the resist-on-metal bilayer can be migrated to different substrates with minimal process alteration, because the material properties of the substrate, such as secondary electron emission or optical reflectance, become irrelevant due to the shielding provided by the metal layer. As demonstrations, we fabricate large-scale plasmonic waveguides and Bragg gratings, adiabatically-modulated plasmonic waveguide couplers, and plasmonic nanoantenna arrays using the resist-on-metal bilayer lift-off process. The process can also be used to define structures formed of other materials such as dielectrics.

4.
BMC Gastroenterol ; 16(1): 59, 2016 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-27268017

RESUMO

BACKGROUND: Since the biological function of c-Jun N-terminal kinase (JNK) in gastric cancer remains unclear, we investigated the clinical significance of JNK activation and its association with FOXO1 activation. METHODS: Immunohistochemical tissue array analysis of 483 human gastric cancer specimens was performed, and the results of the immunostaining were quantified. The correlation between JNK activation (nuclear staining for pJNK) and clinicopathological features, the proliferation index, prognosis or FOXO1 inactivation (cytoplasmic staining for pFOXO1) was analyzed. The SNU-638 gastric cancer cell line was used for in vitro analysis. RESULTS: Nuclear staining of pJNK was found in 38 % of the gastric carcinomas and was higher in the early stages of pTNM (P < 0.001). pJNK staining negatively correlated with lymphatic invasion (P = 0.034) and positively correlated with intestinal type by Lauren's classification (P = 0.037), Ki-67-labeling index (P < 0.001), cyclin D1 (P = 0.045), cyclin E (P < 0.001) and pFOXO1 (P < 0.001). JNK activation correlated with a longer patients survival (P =0.008) and patients with a JNK-active and FOXO1-inactive tumor had a higher survival rate than the remainder of the population (P = 0.004). In vitro analysis showed that JNK inhibition by SP600125 in SNU-638 cells decreased cyclin D1 protein expression and increased FOXO1 activation. Further, JNK inhibition markedly suppressed colony formation, which was partially restored by FOXO1 shRNA expression. CONCLUSIONS: Our results indicate that JNK activation may serve as a valuable prognostic factor in gastric cancer, and that it is implicated in gastric tumorigenesis, at least in part, through FOXO1 inhibition.


Assuntos
Proteína Forkhead Box O1/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neoplasias Gástricas/metabolismo , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Ativação Enzimática , Feminino , Humanos , Imuno-Histoquímica , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Taxa de Sobrevida
5.
Asian-Australas J Anim Sci ; 29(5): 624-30, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26954229

RESUMO

Many studies have reported the frequency and distribution of haplogroups among various cattle breeds for verification of their origins and genetic diversity. In this study, 318 complete sequences of the mtDNA control region from four Korean cattle breeds were used for haplogroup classification. 71 polymorphic sites and 66 haplotypes were found in these sequences. Consistent with the genetic patterns in previous reports, four haplogroups (T1, T2, T3, and T4) were identified in Korean cattle breeds. In addition, T1a, T3a, and T3b sub-haplogroups were classified. In the phylogenetic tree, each haplogroup formed an independent cluster. The frequencies of T3, T4, T1 (containing T1a), and T2 were 66%, 16%, 10%, and 8%, respectively. Especially, the T1 haplogroup contained only one haplotype and a sample. All four haplogroups were found in Chikso, Jeju black and Hanwoo. However, only the T3 and T4 haplogroups appeared in Heugu, and most Chikso populations showed a partial of four haplogroups. These results will be useful for stable conservation and efficient management of Korean cattle breeds.

6.
Opt Express ; 23(9): 11783-9, 2015 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-25969269

RESUMO

We theoretically demonstrate spontaneous PT-symmetry breaking behavior of surface-plasmon polaritons (SPP) in coupled double-slab (DS) waveguides. By virtue of a flat-top field at critical wavelength, the imaginary index of a DS-SPP mode can be controlled via changing the core thickness, while the real index is kept constant. Therefore, a waveguide coupler that consists of a pair of DS-SPP waveguides with different core thicknesses can represent a passive PT-symmetric system, which always maintains symmetry under a real potential. This set-up also represents a good opportunity to investigate the underlying physics of PT-symmetry breaking in non-Hermitian Hamiltonian systems.

7.
Gastric Cancer ; 17(3): 423-30, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24202965

RESUMO

BACKGROUND: Cisplatin (CDDP) is one of the most important chemotherapeutic agents in the treatment of advanced gastric cancer, but its efficacy is limited by CDDP resistance. Because the transcription factor FOXO1 is related to chemoresistance in various cancer cells, we investigated the function of FOXO1 in CDDP resistance in human gastric cancer cells. METHODS: Human gastric cancer cell lines MKN45 and SNU-601 were used. FOXO1 activation was modulated by transfection of FOXO1 AAA mutant gene or FOXO1 shRNA. The effects of FOXO1 on cell growth and CDDP cytotoxicity were assessed by crystal violet assay. Protein expressions of FOXO1, p110α, pAkt, and Akt were analyzed by Western blotting, and FOXO1 mRNA expression was evaluated by semiquantitative reverse transcription-polymerase chain reaction. FOXO1 activity was determined by luciferase reporter assay, and cell apoptosis was assessed by DAPI staining and Western blotting for PARP cleavage. RESULTS: Cisplatin treatment induced FOXO1 expression and activation in both gastric cancer cell lines. FOXO1 overexpression increased the CDDP resistance without changes in cell growth, whereas FOXO1 silencing enhanced CDDP cytotoxicity along with apoptotic characteristics. Both constitutive and CDDP-induced FOXO1 activations were accompanied by an increase in p110α and pAkt expression. Furthermore, Akt inhibition by LY294002 treatment restored the CDDP cytotoxicity that was suppressed by FOXO1 overexpression. CONCLUSION: FOXO1 inhibits CDDP-induced apoptosis in gastric cancer cells via activating PI3K/Akt pathway. Thus, FOXO1 may be an useful pharmacological indicator to predict CDDP efficacy in gastric cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Fatores de Transcrição Forkhead/genética , Neoplasias Gástricas/tratamento farmacológico , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Proteína Forkhead Box O1 , Humanos , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia
8.
Light Sci Appl ; 13(1): 122, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806499

RESUMO

As semiconductor devices shrink and their manufacturing processes advance, accurately measuring in-cell critical dimensions (CD) becomes increasingly crucial. Traditional test element group (TEG) measurements are becoming inadequate for representing the fine, repetitive patterns in cell blocks. Conventional non-destructive metrology technologies like optical critical dimension (OCD) are limited due to their large spot diameter of approximately 25 µm, which impedes their efficacy for detailed in-cell structural analysis. Consequently, there is a pressing need for small-spot and non-destructive metrology methods. To address this limitation, we demonstrate a microsphere-assisted hyperspectral imaging (MAHSI) system, specifically designed for small spot optical metrology with super-resolution. Utilizing microsphere-assisted super-resolution imaging, this system achieves an optical resolution of 66 nm within a field of view of 5.6 µm × 5.6 µm. This approach effectively breaks the diffraction limit, significantly enhancing the magnification of the system. The MAHSI system incorporating hyperspectral imaging with a wavelength range of 400-790 nm, enables the capture of the reflection spectrum at each camera pixel. The achieved pixel resolution, which is equivalent to the measuring spot size, is 14.4 nm/pixel and the magnification is 450X. The MAHSI system enables measurement of local uniformity in critical areas like corners and edges of DRAM cell blocks, areas previously challenging to inspect with conventional OCD methods. To our knowledge, this approach represents the first global implementation of microsphere-assisted hyperspectral imaging to address the metrology challenges in complex 3D structures of semiconductor devices.

9.
Food Sci Anim Resour ; 43(1): 46-60, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36789192

RESUMO

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55°C/3 h) and thermolysin (pH 7.5/37°C/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

10.
J Anim Sci Technol ; 63(1): 149-159, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33987592

RESUMO

This study examined the effects of different wet-aging times on the physicochemical characteristics and microbial profile of longissimus lumborum (LL) and biceps femoris (BF) muscles from Korean native black goat (KNBG) meat. The water holding capacity (WHC), pH, cooking loss, shear force, meat color, free amino acid, total bacteria, and coliform count of KNGB meat were analyzed at 0, 5, 10, and 15 days of wet-aging at 4°C under vacuum packaging. The results showed that different wet-aging times led to significant pH variations between the muscles throughout the aging period. The wet-aging time did not affect the WHC and cooking loss in meat from the LL muscle. In the BF muscle, however, meat wet-aged for five days had a significantly higher WHC and less cooking loss than meat aged for 0, 10, and 15 days. The meat from the LL muscle wet-aged for five days produced tenderer meat (low shear force value) than the unaged meat (p < 0.05). Moreover, the color was similar in the LL muscle regardless of the number of aging days. In the BF muscle, the redness (a*) was higher in the meat wet-aged for 15 days compared to that aged for 0, 5, and 10 days (p < 0.05). Regardless of the muscles, an increase in wet-aging time led to an increase in the total free amino acids contents in both muscles (p < 0.05). On the other hand, the tasty/bitter amino acid ratio was significantly higher for five days of wet-aged meat than 10 and 15 days of aging from the BF muscle. In addition, regardless of the muscles, the total bacteria and coliform counts were significantly lower for five days of wet-aged meat than 10 and 15 days of aging (p < 0.05). Therefore, chevon wet-aged for five days is an optimal aging period under vacuum packaging that fortifies meat quality with a minimal microbial negative defect.

11.
J Anim Sci Technol ; 61(6): 352-358, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31844545

RESUMO

The supplementation effects of sea tangle powders were determined for the meat quality in Korean native black goats. A total 90 castrated male black goats at 3-month age were divided into 3 dietary treatment groups: control (basal diet + mineral block), T1 (0.3% sea tangle feeding with the basal diet), T2 (0.9% sea tangle feeding with the basal diet). At 9-months feeding, 10 goats per treatment group were slaughtered, and the longissimus dorsi muscle samples were vacuum-packed, and subsequently analyzed for physicochemical evaluations. Analysis revealed decrease in the shear force and TBARS values of meat in the sea tangle dietary groups (p < 0.05). The T2 group exhibited increased levels of unsaturated fatty acids such as C16:1, C18:1, C18:2, and C20:4 (p < 0.05). The content of free amino acids with desirable taste such as aspartic acid, glutamic acid, glycine, histidine, and serine were higher in T2, whereas alanine content was higher in both sea tangle dietary groups, as compared to control (p < 0.05). These data indicate that feeding dietary sea tangle as an alternative mineral source results in an improvement in the physicochemical profiles of goat meat.

12.
J Med Food ; 11(1): 78-85, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18361741

RESUMO

This study investigated the inhibitory effects of soy isoflavones and fructooligosaccharide (FOS) on colon carcinogenesis. Sprague-Dawley male rats were injected with 1,2-dimethylhydrazine (DMH) and given experimental diets that contained 0%, 3%, 6%, or 9% FOS with or without soy isoflavones (1,000 mg/kg of diet). After 12 weeks, colonic aberrant crypt foci (ACF) formation, cyclooxygenase-2 (COX-2) expression, and fecal bile acid profiles were determined. The numbers of ACF, the numbers of ACF containing four or more crypts per focus of colonic mucosa, and the levels of COX-2 protein in the colonic epithelial tissues were significantly decreased in a dose-dependent manner in the FOS-fed, DMH-treated rats (P < .001), as compared to the DMH-treated control rats. Soy isoflavones significantly decreased the number of ACF with four or more aberrant crypts per focus (P < .001) and the amount of COX-2 protein (P < .01), independently of the effect of the oligosaccharide. The highest suppression of ACF formation was obtained with soy isoflavones combined with >or=6% FOS. No significant relationship was found between the dosage of FOS or soy isoflavones and the concentration of fecal secondary bile acid. We conclude that the combination of FOS and soy isoflavones inhibits colonic ACF formation and reduces COX-2 expression in DMH-treated rats.


Assuntos
Anticarcinógenos/administração & dosagem , Neoplasias do Colo/prevenção & controle , Ciclo-Oxigenase 2/análise , Glycine max/química , Isoflavonas/administração & dosagem , Oligossacarídeos/administração & dosagem , Animais , Ácidos e Sais Biliares/análise , Colo/enzimologia , Colo/patologia , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/patologia , Dimetilidrazinas , Fezes/química , Mucosa Intestinal/enzimologia , Ratos , Ratos Sprague-Dawley
13.
Nat Commun ; 9(1): 2182, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29872042

RESUMO

Parity-time (PT) symmetry and associated non-Hermitian properties in open physical systems have been intensively studied in search of new interaction schemes and their applications. Here, we experimentally demonstrate an electrical circuit producing key non-Hermitian properties and unusual wave dynamics grounded on anti-PT (APT) symmetry. Using a resistively coupled amplifying-LRC-resonator circuit, we realize a generic APT-symmetric system that enables comprehensive spectral and time-domain analyses on essential consequences of the APT symmetry. We observe an APT-symmetric exceptional point (EP), inverse PT-symmetry breaking transition, and counterintuitive energy-difference conserving dynamics in stark contrast to the standard Hermitian dynamics keeping the system's total energy constant. Therefore, we experimentally confirm unique properties of APT-symmetric systems, and further development in other areas of physics may provide new wave-manipulation techniques and innovative device-operation principles.

14.
Nat Commun ; 8: 14154, 2017 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-28106054

RESUMO

Time-asymmetric state-evolution properties while encircling an exceptional point are presently of great interest in search of new principles for controlling atomic and optical systems. Here, we show that encircling-an-exceptional-point interactions that are essentially reciprocal in the linear interaction regime make a plausible nonlinear integrated optical device architecture highly nonreciprocal over an extremely broad spectrum. In the proposed strategy, we describe an experimentally realizable coupled-waveguide structure that supports an encircling-an-exceptional-point parametric evolution under the influence of a gain saturation nonlinearity. Using an intuitive time-dependent Hamiltonian and rigorous numerical computations, we demonstrate strictly nonreciprocal optical transmission with a forward-to-backward transmission ratio exceeding 10 dB and high forward transmission efficiency (∼100%) persisting over an extremely broad bandwidth approaching 100 THz. This predicted performance strongly encourages experimental realization of the proposed concept to establish a practical on-chip optical nonreciprocal element for ultra-short laser pulses and broadband high-density optical signal processing.

15.
Nat Commun ; 7: 12201, 2016 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-27425577

RESUMO

Recently, synthetic optical materials represented via non-Hermitian Hamiltonians have attracted significant attention because of their nonorthogonal eigensystems, enabling unidirectionality, nonreciprocity and unconventional beam dynamics. Such systems demand carefully configured complex optical potentials to create skewed vector spaces with a desired metric distortion. In this paper, we report optically generated non-Hermitian photonic lattices with versatile control of real and imaginary sub-lattices. In the proposed method, such lattices are generated by vector-field holographic interference of two elliptically polarized pump beams on azobenzene-doped polymer thin films. We experimentally observe violation of Friedel's law of diffraction, indicating the onset of complex lattice formation. We further create an exact parity-time symmetric lattice to demonstrate totally asymmetric diffraction at the spontaneous symmetry-breaking threshold, referred to as an exceptional point. On this basis, we provide the experimental demonstration of reconfigurable non-Hermitian photonic lattices in the optical domain and observe the purest exceptional point ever reported to date.

16.
World J Gastroenterol ; 22(41): 9141-9153, 2016 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-27895401

RESUMO

AIM: To investigated the relationships between HER2, c-Jun N-terminal kinase (JNK) and protein kinase B (AKT) with respect to metastatic potential of HER2-positive gastric cancer (GC) cells. METHODS: Immunohistochemistry was performed on tissue array slides containing 423 human GC specimens. Using HER2-positve GC cell lines SNU-216 and NCI-N87, HER2 expression was silenced by RNA interference, and the activations of JNK and AKT were suppressed by SP600125 and LY294002, respectively. Transwell assay, Western blot, semi-quantitative reverse transcription-polymerase chain reaction and immunofluorescence staining were used in cell culture experiments. RESULTS: In GC specimens, HER2, JNK, and AKT activations were positively correlated with each other. In vitro analysis revealed a positive regulatory feedback loop between HER2 and JNK in GC cell lines and the role of JNK as a downstream effector of AKT in the HER2/AKT signaling pathway. JNK inhibition suppressed migratory capacity through reversing EMT and dual inhibition of JNK and AKT induced a more profound effect on cancer cell motility. CONCLUSION: HER2, JNK and AKT in human GC specimens are positively associated with each other. JNK and AKT, downstream effectors of HER2, co-operatively contribute to the metastatic potential of HER2-positive GC cells. Thus, targeting of these two molecules in combination with HER2 downregulation may be a good approach to combat HER2-positive GC.


Assuntos
Movimento Celular , Transição Epitelial-Mesenquimal , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor ErbB-2/metabolismo , Transdução de Sinais , Neoplasias Gástricas/enzimologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Ativação Enzimática , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Retroalimentação Fisiológica , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Metástase Neoplásica , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Interferência de RNA , Receptor ErbB-2/genética , Transdução de Sinais/efeitos dos fármacos , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Fatores de Tempo , Transfecção
17.
Biofactors ; 22(1-4): 161-3, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15630274

RESUMO

A primary methanol extract (F-ME), secondary butanol-soluble fraction (F-BU), and lignans were prepared from forsythia fruit (Forsythia viridissima L.) and added to 0.5% (w/w) cholesterol diets for male Sprague-Dawley rats weighing 121 +/- 12 g. There were six experimental groups: a control group, 0.2%, 0.4% F-ME supplemented groups, 0.1%, 0.02% F-BU groups and 0.02% lignan group. After 3 weeks of feeding, body weight gains, serum GOT and GPT levels were not different among the groups. HDL-/total cholesterol ratios increased in the 0.2% F-BU and lignan groups compared with the control groups. Liver triglyceride level lowered in most of forsythia groups. Fecal cholesterol excretions increased in the lignan group. Arctiin isolated from the forsythia fruit reduced cholesterol and triglyceride contents in cultured HepG2 cells at 0.01-0.1 microM. These results indicated that the forsythia lignan, arctiin is effective on improving blood lipid status without a significant hepatotoxicity and is to be utilized for the functional foods for lipid-lowering action.


Assuntos
Colesterol na Dieta/farmacologia , Forsythia , Furanos/farmacologia , Glucosídeos/farmacologia , Lignanas/farmacologia , Metabolismo dos Lipídeos , Extratos Vegetais/farmacologia , Sementes , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Peso Corporal/efeitos dos fármacos , Linhagem Celular Tumoral , Suplementos Nutricionais , Humanos , Lipídeos/sangue , Masculino , Ratos , Ratos Sprague-Dawley
18.
J Med Food ; 7(2): 130-5, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15298757

RESUMO

Diabetes mellitus is a chronic disease associated with serious complications that may be linked to increased lipid peroxidation. This study investigated the effects of dietary supplementation of sea tangle on lipid peroxidation and antioxidant systems in streptozotocin (STZ)-induced diabetes. Forty Sprague-Dawley rats were divided into four groups (n = 10 each) fed AIN76-based diets with either sea tangle powder, water extract of sea tangle, or sodium alginate, or a control diet with no supplement. On day 21 after beginning the diets, rats received intramuscular injections of STZ (45 mg/kg of body weight) to induce diabetes. Experimental diet feeding was continued for 3 more weeks. Dietary supplementation with water extract of sea tangle resulted in lower plasma glucose compared with the control and sodium alginate groups. There was no significant difference in plasma and hepatic lipid peroxides among the groups. Sea tangle and sodium alginate did not affect activities of catalase and glutathione peroxidase; however, supplementation of water extract of sea tangle resulted in higher superoxide dismutase activity as compared with the control and sodium alginate groups. The plasma concentration of alpha-tocopherol increased in the sea tangle water extract group, but the hepatic concentration of alpha-tocopherol was not affected by dietary supplementation. Plasma retinol was not different among experimental groups. In conclusion, our results showed that water extract of sea tangle reduces plasma glucose and protects the antioxidant system in diabetic rats. These results suggest that water extract of sea tangle contains unknown physiologically active components, other than alginic acid, that may exert a protective effect against diabetes.


Assuntos
Antioxidantes/metabolismo , Glicemia/análise , Dieta , Phaeophyceae , Vitamina A/análogos & derivados , Alginatos/administração & dosagem , Animais , Peso Corporal , Diabetes Mellitus Experimental , Suplementos Nutricionais , Diterpenos , Ingestão de Alimentos , Ácido Glucurônico/administração & dosagem , Ácidos Hexurônicos/administração & dosagem , Fígado/química , Masculino , Phaeophyceae/química , Ratos , Ratos Sprague-Dawley , Ésteres de Retinil , Vitamina A/análise , Vitamina A/sangue , alfa-Tocoferol/análise , alfa-Tocoferol/sangue
19.
J Nutr Sci Vitaminol (Tokyo) ; 50(1): 32-7, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15228215

RESUMO

Six polyphenolic compounds were isolated from ethylacetate extract secondary to 80% ethanol extraction of defatted safflower seeds. They were categorized into three types: lignans, flavones and serotonin derivatives. Female Sprague-Dawley rats weighing 163.4 +/- 6.3 g were ovariectomized (Ovx) and fed either ethylacetate extract at a level of 1% (w/w) or three types of safflower polyphenolic compounds at a level of 200 mg/kg in a diet containing 0.5% (w/w) cholesterol for four wk. The sham and Ovx control groups were fed the same diet without safflower components. Plasma GOT and GPT levels did not differ among the six experimental groups. The plasma levels of total cholesterol were reduced in the four safflower groups by 20-30% as compared to the Ovx control. The plasma level of HDL-cholesterol was higher in the Ovx+ethylacetate extract group or appeared to be in the three Ovx+safflower polyphenolic groups than in the Ovx control. The level of plasma triglyceride was also significantly lower in the Ovx+lignan group than in the Ovx control. The liver level of cholesterol was significantly reduced in the Ovx+ethylacetate extract group. Fecal excretion of cholesterol increased by the safflower lignans and flavones, whereas that of bile acid was not significantly changed by the safflower polyphenols. Matairesinol and acacetin isolated from safflower seeds reduced the cholesterol content in cultured HepG2 cells at a concentration of 0.01-0.1 microM and all three safflower polyphenolics decreased triglyceride content at the concentration of 0.1 microM. These results suggest that safflower polyphenols have the effect of improving blood lipid status via increasing HDL-cholesterol formation and cholesterol excretion without significant uterotropic action in estrogen-deficient animals.


Assuntos
Carthamus tinctorius/química , Colesterol na Dieta/administração & dosagem , Lipídeos/análise , Fígado/química , Fenóis/administração & dosagem , Sementes/química , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Ácidos e Sais Biliares/análise , Peso Corporal , Linhagem Celular , Colesterol/análise , Colesterol/sangue , Dieta , Fezes/química , Feminino , Flavonoides/administração & dosagem , Lipídeos/sangue , Tamanho do Órgão , Ovariectomia , Extratos Vegetais/administração & dosagem , Ratos , Ratos Sprague-Dawley , Triglicerídeos/análise , Triglicerídeos/sangue
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