RESUMEN
To date, only limited evidence has supported the notion that resistance exercise positively impacts non-alcoholic fatty liver disease. We evaluated the effects of resistance exercise on the metabolic parameters of non-alcoholic fatty liver disease (NAFLD) in 53 patients who were assigned to either a group that performed push-ups and squats 3 times weekly for 12 weeks (exercise group; n=31) or a group that did not (control; n=22). Patients in the control group proceeded with regular physical activities under a restricted diet throughout the study. The effects of the exercise were compared between the 2 groups after 12 weeks. Fat-free mass and muscle mass significantly increased, whereas hepatic steatosis grade, mean insulin and ferritin levels, and the homeostasis model assessment-estimated insulin resistance index were significantly decreased in the exercise group. Compliance with the resistance exercise program did not significantly correlate with patient background characteristics such as age, sex, BMI and metabolic complications. These findings show that resistance exercise comprising squats and push-ups helps to improve the characteristics of metabolic syndrome in patients with non-alcoholic fatty liver disease.
Asunto(s)
Terapia por Ejercicio/métodos , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/terapia , Entrenamiento de Fuerza , Anciano , Alanina Transaminasa/sangre , Aspartato Aminotransferasas/sangre , Índice de Masa Corporal , LDL-Colesterol/sangre , Femenino , Ferritinas/sangre , Homeostasis , Humanos , Insulina/sangre , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Cooperación del PacienteRESUMEN
We have identified a non-insulin-dependent diabetic patient with fasting hyperinsulinemia (90 microU/ml), an elevated insulin:C-peptide molar ratio (1.68; normal, 0.05-0.20), normal insulin counterregulatory hormone levels, and an adequate response to exogenously administered insulin. Insulin-binding antibodies were absent from serum, erythrocyte insulin receptor binding was normal, and greater than 90% of circulating immunoreactive insulin coeluted with 125I-labeled insulin on gel filtration. The patient's insulin diluted in parallel with a human standard in the insulin radioimmunoassay, confirming close molecular similarity. The patient's insulin was purified from serum and shown to possess both reduced binding and ability to stimulate glucose uptake and oxidation in vitro. Analysis of the patient's insulin by high-performance liquid chromatography (HPLC) revealed two products: 7.3% of insulin immunoreactivity coeluted with the human standard, while the remaining 92.7% eluted as a single peak with increased hydrophobicity. Family studies confirmed the presence of hyperinsulinemia in four of five relatives in three generations, with secretion of an abnormal insulin documented by HPLC in the three tested. Leukocyte DNA was harvested from the propositus and the insulin gene cloned. One allele was normal, but the other displayed a thymine for guanine substitution at nucleotide position 1298 from the putative cap site, resulting in a leucine for valine substitution at position 3 of the insulin A chain. Insulin Wakayama is therefore identified as [LeuA3] insulin.
Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Insulina/análogos & derivados , Tejido Adiposo/metabolismo , Animales , Secuencia de Bases , Péptido C/sangre , ADN/genética , ADN Recombinante , Desoxiglucosa/metabolismo , Diabetes Mellitus Tipo 2/genética , Femenino , Glucosa/metabolismo , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , Insulina/genética , Resistencia a la Insulina , Persona de Mediana Edad , Ratas , Receptor de Insulina/metabolismoRESUMEN
The objective of this study was to find serum indicators of gastric ulcers in foals. By using two-dimensional electrophoresis of serum proteins, three distinct spots were detected in samples from foals with gastric ulcers detected endoscopically. One of them appeared with high frequency and was identified by partial digestion with trypsin and subsequent nano-electrospray ionisation-tandem mass spectrometry (nanoesi-ms/ms) analysis as an alpha(1)-antitrypsin. Western blot analysis, using an antibody against human alpha(1)-antitrypsin, revealed at least two bands, of molecular weight 58 kDa and 55 kDa, in the sera. The 55 kDa band was detected in 44 of 47 serum samples from foals with gastric ulcers, but in only three of 22 serum samples from healthy foals.
Asunto(s)
Enfermedades de los Caballos/sangre , Úlcera Gástrica/sangre , alfa 1-Antitripsina/sangre , Secuencia de Aminoácidos , Animales , Animales Recién Nacidos , Anticuerpos Monoclonales , Biomarcadores/sangre , Western Blotting/veterinaria , Electroforesis en Gel Bidimensional/veterinaria , Enfermedades de los Caballos/metabolismo , Caballos , Peso Molecular , Isoformas de Proteínas , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/veterinaria , Úlcera Gástrica/metabolismo , alfa 1-Antitripsina/inmunología , alfa 1-Antitripsina/metabolismoRESUMEN
We developed a fast X-ray detector system for nuclear resonant scattering (NRS) experiments. Our system employs silicon avalanche photo-diode (Si-APD) as a fast X-ray sensor. The system is able to acquire both timing and energy of a single X-ray photon simultaneously in a high rate condition, 106 counts per second for one Si-APD. The performance of the system was investigated in SPring-8, a synchrotron radiation facility in Japan. Good time resolution of 120 ps (FWHM) was achieved with a slight tail distribution in the time spectrum by a level of 10-9 at 1 ns apart from the peak. Using this system, we successfully observed the NRS from the 26.27-keV level of mercury-201, which has a half-life of 630(50) ps. We also demonstrated the reduction of background events caused by radioactive decays in a radioactive sample by discriminating photon energy.
RESUMEN
Antigenotoxic and antimutagenic activities of green tea extract and tea-derived polyphenols have been studied using in vitro and in vivo experiments. However, antigenotoxic substances in the non-polyphenolic fraction of green tea have been poorly elucidated. In the present study, the effect of the non-polyphenolic fraction of green tea on genotoxin-induced umu C gene expression was analyzed using a tester bacteria, and potent antigenotoxic substances in the non-polyphenolic fraction were identified. The non-polyphenolic fraction of green tea showed strong suppressive activities against umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1) or mitomycin C (MMC) in the presence or absence of S9 metabolizing enzyme mixture. The non-polyphenolic fraction of green tea exhibited major two-color bands in a silica gel TLC and they were identified as chlorophyll-related compounds, pheophytins a and b, judged by their specific colors, Rf values in silica gel TLC and absorption spectra. These pigments showed significant suppressive activities against umu C gene expression in tester bacteria induced by Trp-P- and MMC in a dose-dependent manner. These results suggest that the non-polyphenolic fraction of green tea contains pheophytins a and b as potent antigenotoxic substances.
Asunto(s)
Antimutagênicos/farmacología , Proteínas Bacterianas/genética , Proteínas de Escherichia coli , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Feofitinas/farmacología , Salmonella typhimurium/genética , Té/química , ADN Polimerasa Dirigida por ADN , Respuesta SOS en Genética/efectos de los fármacos , Spinacia oleracea/químicaRESUMEN
Chlorophyll-related compounds pheophytin a and b have been recently identified as antigenotoxic substances in the non-polyphenolic fraction of green tea (Camellia sinensis), which suppressed umu C gene expression in tester bacteria induced by various genotoxins (Okai and Higashi-Okai, Cancer Lett. 118 (1997) 117-123). In the present study, the authors analyzed in vivo and in vitro effects of pheophytin a and b from the non-polyphenolic fraction of green tea on tumor promotion in mouse skin as follows. (1) When pheophytin a and b from green tea were topically applied prior to each treatment with a tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA) on BALB/c mouse skin initiated by 7,12 dimethylbenz[a]anthracene (DMBA), they caused suppression in a dose-dependent fashion against skin tumorigenesis. (2) Pheophytin a and b exhibited significant suppressions against TPA-induced inflammatory reaction, such as edema formation, in BALB/c mouse ear skin in a dose-dependent manner. (3) Pheophytin a and b from green tea showed inhibitory effects against early induction of ornithine decarboxylase (ODC) in BALB/c mouse skin fibroblasts caused by TPA. These results suggest that pheophytin a and b from the non-polyphenolic fraction have potent suppressive activities against tumor promotion in mouse skin.
Asunto(s)
Anticarcinógenos/farmacología , Neoplasias Experimentales/prevención & control , Feofitinas/farmacología , Neoplasias Cutáneas/prevención & control , Té/química , Células 3T3 , 9,10-Dimetil-1,2-benzantraceno/farmacología , Animales , Anticarcinógenos/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Edema/inducido químicamente , Edema/prevención & control , Femenino , Ratones , Ratones Endogámicos BALB C , Ornitina Descarboxilasa/metabolismo , Feofitinas/aislamiento & purificación , Piel/efectos de los fármacos , Piel/enzimología , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
Some of epidemiological data indicated that ubiquitous consumption of seaweeds in Japan may be a possible protective factor against some types of tumor. To analyse this problem, the authors studied the antimutagenic and antitumor promotion activities in methanol-soluble extracts of typical edible seaweeds which showed suppressive effects on 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1)-induced umu C gene expression in SOS response of Salmonella typhimurium (TA 1535/pSK 1002) and 12-O-tetradecanoylphorbol-13-acetate (TPA)-dependent ornithine decarboxylase induction in BALB/c 3T3 fibroblast cells. Although eight varieties of edible seaweeds including chlorophyta, Phaenophyta and Rhodophyta showed significant antimutagenic and antipromotion activities, they expressed the activities different from each other. Among these seaweeds, Enteromorpha prolifera ('Sujiaonori' in Japanese) and Porphyra tenera ('Asakusanori') showed relatively strong suppressive activities in both antimutagenic and antipromotion assays compared with other seaweeds. These seaweeds contained considerable amounts of beta-carotene as a possible active principle with anticarcinogenic activity. This compound was partially associated with the antimutagenic activity in the seaweed extract, but did not contribute to the antipromotion activity of seaweed extract under our experimental conditions. These results strongly suggest that Japanese edible seaweeds have possible antimutagenic and antipromotion activities probably associated with antitumor activity.
Asunto(s)
Anticarcinógenos/farmacología , Antimutagênicos/farmacología , Proteínas de Escherichia coli , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Ornitina Descarboxilasa/biosíntesis , Algas Marinas , Células 3T3 , Animales , Anticarcinógenos/aislamiento & purificación , Antimutagênicos/aislamiento & purificación , Proteínas Bacterianas/genética , Carotenoides/análisis , Carotenoides/aislamiento & purificación , ADN Polimerasa Dirigida por ADN , Inducción Enzimática/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Genes Bacterianos , Metanol , Ratones , Ratones Endogámicos BALB C , Oncogenes , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Salmonella typhimurium/crecimiento & desarrollo , Algas Marinas/química , Acetato de Tetradecanoilforbol/toxicidad , Factores de Tiempo , beta CarotenoRESUMEN
Recently, a relatively strong antimutagenic activity has been detected in the extract of Porphyra tenera (Asakusa-nori in Japanese) which showed a suppressive effect on mutagen-induced umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002 (Okai et al. (1994) Cancer Lett., 87, 25-32). In the present paper, we analyzed the active principles for the antimutagenic activity in an extract of Porphyra tenera and detected three color spots on a silica gel TLC plate which indicated very similar Rf values and absorbance spectra of standard pigments such as beta-carotene, chlorophyll a and lutein. The seaweed pigments recovered from preparative silica gel TLC corresponding to beta-carotene, chlorophyll a and lutein exhibited significant suppressive activities against mutagen-induced umu C gene expression and combined treatment with these pigments showed an additive effect compared with single treatment with each pigment. Furthermore, the standard pigments prepared from other biological sources also exhibited similar anti-mutagenic activities. The significance of this finding is discussed from the protective role of seaweed pigments against mutagenesis probably associated with carcinogenesis.
Asunto(s)
Antimutagênicos/farmacología , Pigmentos Biológicos/farmacología , Rhodophyta/química , Carotenoides/farmacología , Clorofila/farmacología , Clorofila A , Luteína/farmacología , Pruebas de Mutagenicidad , Algas Marinas/química , beta CarotenoRESUMEN
Although previous epidemiological studies have indicated that beta-carotene is an important agent for the chemical prevention against carcinogenesis, a recent prospective study has strikingly suggested that supplementation with beta-carotene significantly increased the incidence of some types of cancer (The alpha-Tocopherol and beta-Carotene Cancer Prevention Study Group, New Engl. J. Med., 330 (1994) 1031-1035). To analyze the discrepancy of this problem, the authors analyze the effects of beta-carotene on biochemical and biological events associated with carcinogenesis by in vitro experiments. (1) All-trans beta-carotene enhanced the proliferation and DNA synthesis of BALB/c 3T3 cells induced by a tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and fetal bovine serum, although beta-carotene itself did not show mitogenic activity. (2) All-trans beta-carotene caused a remarkable stimulation for the early induction of ornithine decarboxylase (ODC) activity after the stimulation of TPA and fetal bovine serum. (3) All-trans beta-carotene exhibited significant antimutagenic activity which suppresses umu C gene expression in Salmonella typhimurium (TA 1535/pSK 1002) induced by a typical mutagen, 2-aminoanthracene (2-AA). These experimental results suggest that all-trans beta-carotene might cause beneficial and harmful effects on different phases of carcinogenesis.
Asunto(s)
Células 3T3/efectos de los fármacos , Antimutagênicos/farmacología , Proteínas Bacterianas/biosíntesis , Carcinógenos/toxicidad , Carotenoides/farmacología , Proteínas de Escherichia coli , Ornitina Descarboxilasa/metabolismo , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Acetato de Tetradecanoilforbol/toxicidad , Células 3T3/citología , Células 3T3/enzimología , Animales , Antracenos/toxicidad , Antimutagênicos/toxicidad , Proteínas Bacterianas/genética , Carotenoides/toxicidad , Bovinos , División Celular/efectos de los fármacos , ADN/biosíntesis , ADN/efectos de los fármacos , ADN Polimerasa Dirigida por ADN , Interacciones Farmacológicas , Inducción Enzimática/efectos de los fármacos , Sangre Fetal , Expresión Génica/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Mutágenos/toxicidad , Ornitina Descarboxilasa/biosíntesis , Ornitina Descarboxilasa/efectos de los fármacos , Salmonella typhimurium/metabolismo , beta CarotenoRESUMEN
Potent antigenotoxic and anti-tumor promoting activities of a Japanese edible seaweed, Enteromorpha prolifera (Sujiao-nori in Japanese) were previously identified using an in vitro cell culture experiment (Y. Okai, K. Higashi-Okai, S. Nakamura, Y. Yano, S. Otani, Cancer Lett. 87 (1994) 25-32). However, in vivo anti-carcinogenic activity of this seaweed has not been elucidated until now. In the present study, the anticarcinogenic activity of E. prolifera was analyzed using an initiation and promotion model experiment of mouse skin tumorigenesis caused by 7,12-dimethylbenz[a]anthracene (initiator) and 12-O-tetradecanoylphorbol-13-acetate (promoter). (1) Application of the extract of E. prolifera prior to the treatment with a tumor initiator or promoter caused a significant suppression against skin tumorigenesis, and the combined application of the extract prior to both treatments with initiator and promoter exhibited much stronger suppression against the same skin tumorigenesis. (2) As a possible active principle for the anticarcinogenic activity of the extract, we propose a chlorophyll-related compound, pheophytin-a, which has been recently identified in the extract of this alga as an antigenotoxic substance (Y. Okai, K. Higashi-Okai, J. Sci. Food Agric. 74 (1997) 531-535), and showed significant suppressive effects in the same tumorigenesis experiment. These results suggest that E. prolifera has a potent suppressive activity against chemically induced mouse skin tumorigenesis through the suppression at the initiation and promotion phases, and that pheophytin-a might be partially associated with the in vivo anticarcinogenic activity.
Asunto(s)
Anticarcinógenos/uso terapéutico , Antineoplásicos Fitogénicos/uso terapéutico , Feofitinas/uso terapéutico , Extractos Vegetales/uso terapéutico , Algas Marinas , Neoplasias Cutáneas/prevención & control , 9,10-Dimetil-1,2-benzantraceno , Animales , Pruebas de Carcinogenicidad , Carcinógenos , Cromatografía Líquida de Alta Presión , Cromatografía en Capa Delgada , Relación Dosis-Respuesta a Droga , Femenino , Ratones , Ratones Endogámicos ICR , Extractos Vegetales/aislamiento & purificación , Algas Marinas/química , Neoplasias Cutáneas/inducido químicamente , Acetato de TetradecanoilforbolRESUMEN
Many studies have shown that the kidney plays an important role in the metabolism of many proteins and small peptides. To understand insulin handling in the kidney, we examined urinary insulin excretion under several conditions in patients with mutant insulin syndrome (MIS; insulin Wakayama). Urinary excretion of insulin was studied using high-performance liquid chromatography analysis in patients with MIS. In these patients, most of the insulin extracted from a 24-hour urine collection and from urine collected after stimulation of insulin secretion by glucose or glucagon was normal insulin, whereas 90% of serum insulin is structurally abnormal (Leu-A3 insulin). On the other hand, arginine, which is known as an inhibitor of renal tubular reabsorption, increased urinary excretion of Leu-A3 insulin. The ratio of Leu-A3 and normal insulin in urine after arginine was similar to that in serum. A large amount of Leu-A3 insulin is excreted in urine when reabsorption of insulin at renal tubules is inhibited by arginine. These data indicate that normal and Leu-A3 insulin are filtered through the glomerulus with relatively little restriction. Using the fact that basal urine has a high concentration of normal insulin and an extremely low concentration of Leu-A3 insulin, which has less receptor-binding affinity, we speculated some possibilities. One possibility is that both forms of insulin are reabsorbed by the tubular cells, but with different efficiencies. Leu-A3 insulin absorption in more complete, and this suggests differences in the uptake pathways that may account for the differences in response to arginine infusions. Another possibility is that only normal insulin is secreted from tubules into urine which is mediated by receptors. Our results provide new insight into renal metabolism of insulin and showed that MIS is a useful model for studying it.
Asunto(s)
Insulina/metabolismo , Riñón/metabolismo , Adulto , Estudios de Casos y Controles , Cromatografía Líquida de Alta Presión , Humanos , Insulina/análogos & derivados , Insulina/sangre , Insulina/orina , Persona de Mediana Edad , SíndromeRESUMEN
para-Nonylphenol (NP) showed a dose-dependent inhibition against the cell growth of Bacillus subtilis, Micrococcus luteus, Pseudomonas aeruginosa and Staphylococcus aureus at 5-100 microM. However, other typical plastic-derived endocrine disruptors such as bisphenol A and di-2-ethylhexyl phthalate (DEHP) did not significantly affect the cell growth of these bacteria at 5-100 microM. The NP-induced cell growth inhibition was restored when concomitantly supplemented with lipophilic antioxidants such as alpha-tocopherol and beta-carotene, but not with hydrophilic antioxidants, ascorbic acid and (-)-epigallocatechin gallate (EGCG). NP also suppressed in a dose-dependent manner cellular oxygen consumption and glucose-induced proton extrusion of these bacteria at 10-100 microM. Both effects were prevented when added with alpha-tocopherol and beta-carotene, but not with ascorbic acid and EGCG. The significance of these results is discussed from the viewpoint of environmental microbiology and a possible biochemical mechanism of the inhibitory effect of NP is suggested.
Asunto(s)
Antioxidantes/farmacología , Bacterias/efectos de los fármacos , Fenoles/farmacología , Vitamina E/farmacología , beta Caroteno/farmacología , Bacterias/crecimiento & desarrollo , Bacterias/metabolismo , Transporte de Electrón/efectos de los fármacos , Glucosa/farmacología , Consumo de Oxígeno/efectos de los fármacos , ProtonesRESUMEN
The cell growth-modulating activity of an endocrine disruptor, p-nonylphenol (NP), was estimated using the yeast Saccharomyces cerevisiae as a simple model of eukaryotic cells. NP caused a dose-dependent suppressive effect on cell growth of S. cerevisiae at 10, 25 and 50 microM. The NP-induced cell growth inhibition was restored when concomitantly lipophilic antioxidants such as alpha-tocopherol and beta-carotene were supplied, but not the hydrophilic antioxidants ascorbic acid or (-)epigallocatechin gallate (EGCG). The cellular oxygen consumption of S. cerevisiae was also inhibited in a dose-dependent fashion by the extracellular addition of NP, and pretreatment with alpha-tocopherol and beta-carotene suppressed NP-induced inhibition of cellular oxygen consumption, but ascorbic acid and EGCG were not effective. Furthermore, NP caused a marked generation of radical oxygen species (ROS) in S. cerevisiae, which was suppressed by treatment with alpha-tocopherol and beta-carotene, but not with ascorbic acid and EGCG. However, NP did not show a significant inhibitory effect on cell growth and survival of mitochondria-deficient petite mutant cells and they showed a relatively weak ROS-generating activity compared with parent yeast cells. These results suggest that NP-induced inhibition of cell growth and oxygen consumption in S. cerevisiae might be possibly associated with ROS generation in yeast mitochondria. The significance of this finding is discussed from the viewpoint of NP-induced oxidative stress against eukaryotic cells.
Asunto(s)
Antioxidantes/farmacología , Fenoles/farmacología , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/crecimiento & desarrollo , Medios de Cultivo , Mitocondrias/genética , Mitocondrias/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Saccharomyces cerevisiae/genéticaRESUMEN
Islet amyloid polypeptide (IAPP/Amylin) is a novel peptide which was extracted from islet amyloid deposits in patients with non-insulin-dependent diabetes mellitus (NIDDM). However, its pattern of secretions and plasma concentrations under various conditions has not yet been made clear enough. In this study, we examined IAPP secretion from islet beta-cells in vitro using cultured islet cells of neonatal rat pancreas and plasma IAPP responses under various conditions in vivo in normal control subjects and patients with glucose intolerance. Our data revealed that (1) IAPP is co-secreted with insulin from islet cells of the rat pancreas by glucose and non-glucose stimuli; (2) fasting plasma IAPP levels in normal control subjects are 24.9 +/- 2.0 pg/ml and the molar ratio of IAPP/insulin is approximately 1/7; (3) fasting IAPP levels are high in obese patients and low in insulin-dependent diabetic patients, and the molar ratio of IAPP/C-peptide in NIDDM patients is lower than that in normal control subjects, suggesting the basal hyposecretion of IAPP relative to insulin in NIDDM; and (4) the obese patients who had a hyperresponsiveness of insulin relative to C-peptide had the hyperresponsiveness of IAPP relative to C-peptide during an oral glucose load, suggesting that IAPP may have some physiological effect in glucose metabolism.
Asunto(s)
Amiloide/metabolismo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus/sangre , Islotes Pancreáticos/metabolismo , Obesidad , Adulto , Amiloide/sangre , Animales , Animales Recién Nacidos , Glucemia/metabolismo , Péptido C/sangre , Células Cultivadas , Diabetes Mellitus/fisiopatología , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Técnica de Clampeo de la Glucosa , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/sangre , Polipéptido Amiloide de los Islotes Pancreáticos , Persona de Mediana Edad , Ratas , Valores de ReferenciaRESUMEN
A significant antimutagenic activity was found in the hot water-soluble extract from a common edible brown alga, Laminaria japonica (Makonbu in Japanese) which showed suppressive effects on umu gene expression of the SOS response against DNA damage in Salmonella typhimurium (TA1535/pSK1002). The extract showed a drastic antimutagenic activity against 2-acetylaminofluorene (2-AAF)- or 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1)-induced mutagenesis which requires liver-metabolizing enzymes, whereas the same extract exhibited weak but significant inhibitory effects on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)- or furylfuramide (AF-2)-induced mutagenesis in the absence of liver-metabolizing enzymes. Among these antimutagenic activities, the minor activity was found in the polysaccharide fraction of the extract which showed roughly equal antimutagenic activities against all the mutagens tested. The major activity was detected in the nonpolysaccharide fraction which exhibited a relatively strong antimutagenic activity against 2-AAF- or Trp-P-1-induced mutagenesis but a weak activity against MNNG- or AF-2-induced mutagenesis. The nonpolysaccharide fraction was further separated into high- or low-molecular-weight fractions and the latter fraction showed a much stronger activity than the former fraction. In addition, similar antimutagenic activities were detected in polysaccharide and nonpolysaccharide fractions from the extract of the other edible brown alga, Undaria pinnatifida (Wakame in Japanese). These experimental results indicate that the hot water-soluble extract of Laminaria japonica or Undaria pinnatifida contains heterogenous antimutagenic activities against typical genotoxic substances. The significance of this finding is discussed from the viewpoint of the protection against genotoxic substances by traditional edible seaweeds in Japan.
Asunto(s)
Antimutagênicos/farmacología , Phaeophyceae/química , Extractos Vegetales/farmacología , Expresión Génica/efectos de los fármacos , Peso Molecular , Pruebas de Mutagenicidad , Salmonella typhimurium/efectos de los fármacos , Algas MarinasRESUMEN
The potentially protective role of chlorophyllin, the sodium and copper salt of chlorophyll a against the initiation and promotion stages in carcinogenesis was studied by in vitro short-term assays. Chlorophyllin showed a dose-dependent suppressive effect on 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indol (Trp-P-1)-induced umu C gene expression of Salmonella typhimurium (TA 1535/pSK 1002) in the presence of metabolizing enzyme mixture. The similar inhibitory effect of chlorophyllin was detected in mitomycin C (MMC)-dependent umu C gene expression in the absence of metabolizing enzyme mixture. Furthermore chlorophyllin also exhibited a dose-dependent inhibition on 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced ornithine decarboxylase (ODC) activity of 3T3 fibroblast cells at the same concentrations. However, when chlorophyll a isolated from Japanese tea leaves was applied on the same assay systems as a comparative experiment, chlorophyll a showed much weaker activity compared with that of chlorophyllin. The significance of this finding is discussed from the viewpoint of the protective role of chlorophyllin against carcinogenesis.
Asunto(s)
Antimutagênicos/administración & dosificación , Proteínas Bacterianas/antagonistas & inhibidores , Clorofilidas/administración & dosificación , Proteínas de Escherichia coli , Inhibidores de la Ornitina Descarboxilasa , Salmonella typhimurium/genética , Células 3T3 , Animales , Proteínas Bacterianas/genética , ADN Polimerasa Dirigida por ADN , Inducción Enzimática/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Ornitina Descarboxilasa/biosíntesis , Ornitina Descarboxilasa/genéticaRESUMEN
Effects of retinoids, carotenoids and antioxidant vitamins were studied by mutagen-induced umu C gene expression system in Salmonella typhimurium (TA 1535/pSK 1002). Retinol (vitamin A), retinol acetate and retinoic acid showed remarkable inhibitory activities, whereas retinol palmitate exhibited significant but weak activity for umu C gene expression in tester bacteria induced by 3-amino-3,4-dimethyl-5H-pyrido[4.3-b]indol (Trp-P-1) in the presence of hepatic metabolizing enzymes (S9 mixture). Carotenoids having provitamin A activity (beta-carotene and canthaxanthin) exhibited moderate suppressive effects on the same experimental system. The ranks of suppressive activities were retinol > retinol acetate > retinoic acid > canthaxanthin > beta-carotene > retinol palmitate and their doses for inhibition by 50% (ID50) were estimated to be 1.2 x 10(-7), 3.0 x 10(-7), 5.4 x 10(-7), 1.5 x 10(-6), 4.0 x 10(-5) and 6.0 x 10(-5) M, respectively. However, they did not cause significant inhibition on umu C gene expression induced by direct-acting mutagen (adriamycin or mitomycin C) in the absence of S9 mixture. Inhibition of umu gene expression appears to be due to inhibition of P450-mediated metabolic activation of the heterocyclic amine Trp-P-1. Ascorbic acid (vitamin C) showed weak but significant suppressive activity at high-dose concentrations (3 x 10(-6) - 10(-4)M). However, alpha-tocopherol did not exhibit significant suppression at all dose concentrations. The significance of the experimental results is discussed from the viewpoint of the chemoprevention against genotoxicity associated with carcinogenesis.
Asunto(s)
Proteínas Bacterianas/efectos de los fármacos , Carotenoides/farmacología , Proteínas de Escherichia coli , Expresión Génica/efectos de los fármacos , Retinoides/farmacología , Salmonella typhimurium/efectos de los fármacos , Vitaminas/farmacología , Animales , Antimutagênicos/farmacología , Antioxidantes/farmacología , Proteínas Bacterianas/genética , Carbolinas/toxicidad , ADN Polimerasa Dirigida por ADN , Relación Dosis-Respuesta a Droga , Compuestos Heterocíclicos/toxicidad , Hígado/efectos de los fármacos , Hígado/enzimología , Mutágenos/toxicidad , Ratas , Ratas Sprague-Dawley , Salmonella typhimurium/genéticaRESUMEN
Di-2-ethylhexyl phthalate (DEHP) is the most extensively used phthalate ester as a plasticizer for plastic products made of polyvinyl chloride (PVC), and previous mutagenic and genotoxic studies have shown positive and negative results of DEHP-induced genotoxicity. To elucidate this discrepancy, we reestimated the genotoxicity of DEHP in more detail using the umu C gene expression system in Salmonella typhimurium (TA 1535/pSK 1002) which reflects SOS response against genotoxin-induced DNA damage. Although DEHP itself did not have a significant effect on umu C gene expression in tester bacteria at 0.5 to 4 mM, higher concentrations of DEHP (2 and 4 mM) caused a weak induction of umu C gene expression in the presence of commercially available S-9 mixture. Rat liver S-9 fraction alone also showed a similar weak inducing activity in the absence of substrates for drug-metabolizing enzymes. When DEHP was preincubated with S-9 fraction of various rat organs and applied to the umu C gene expression assay, S-9 fraction of rat pancreas had the strongest inducing activity, and S-9 fractions of liver and intestine homogenates showed weak but significant activities. However, S-9 fractions of lung and kidney homogenates did not exhibit any significant activities. These S-9 fractions have proportional lipase activities comparable with umu C gene expression activities. Furthermore, when DEHP was treated with highly purified lipase from porcine pancreas, a significant umu C gene expression was observed and this expression was enhanced in the presence of 1 or 5 mM bile acids such as choric acid and deoxychoric acid. These results suggest that DEHP itself has no or very low genotoxicity, but enzymatic and non-enzymatic factors in specific tissues induce DEHP-dependent genotoxic activity.
Asunto(s)
Dietilhexil Ftalato/toxicidad , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Genes Bacterianos/genética , Plastificantes/toxicidad , Salmonella typhimurium/genética , Animales , Ácidos y Sales Biliares/fisiología , Lipasa/fisiología , Masculino , Ratas , Ratas Wistar , PorcinosRESUMEN
Potent antigenotoxic and anti-tumor promoting activities of chlorophyll a from green tea (camellia sinensis) have been shown using in vitro cell culture experiments (Okai Y. et al. (1996) Mutation Res., 370, 11-17). In the present study, the authors analyzed in vivo effects of chlorophyll a and b from green tea on tumor promotion in mouse skin in the following ways. 1. When chlorophyll a and b from green tea were applied before each treatment by a tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on BALB/c mouse skin initiated by 7, 12-dimethylbenz [a] an-thracene (DMBA), they caused significant suppression in a dose-dependent manner against BALB/c mouse skin tumorigenesis. 2. Chlorophyll a and b showed significant suppressive effects against TPA-induced inflammatory reaction such as edema formation in BALB/c mouse ear skin in a dose-dependent fashion. These results suggest that chlorophyll a and b possess potent suppressive activities against tumor promotion in mouse skin.
Asunto(s)
Carcinógenos/antagonistas & inhibidores , Clorofila/farmacología , Pigmentos Biológicos/farmacología , Neoplasias Cutáneas/prevención & control , Té/química , Acetato de Tetradecanoilforbol/antagonistas & inhibidores , 9,10-Dimetil-1,2-benzantraceno , Animales , Clorofila/aislamiento & purificación , Clorofila A , Edema/prevención & control , Ratones , Ratones Endogámicos BALB C , Pigmentos Biológicos/aislamiento & purificaciónRESUMEN
Antioxidant activity of green tea extract or tea-derived polyphenols has been extensively studied. However, antioxidant activity in the non-polyphenolic fraction of green tea has been poorly analyzed. In the present study, we analyzed the antioxidant activity of the non-polyphenolic fraction of the residual green tea (Camellia sinensis) after hot water extraction using the aluminum chloride method. The non-polyphenolic fraction of residual green tea caused a significant suppression against hydroperoxide generation from oxidized linoleic acid in a dose-dependent manner. When the concentrate of the non-polyphenolic fraction was applied to a silica gel TLC plate and developed, six color spots were observed, which were considered to be chlorophylls a and b, pheophytins a and b, carotenoids, such as beta-carotene and lutein according to their specific colors, Rf values of silica gel TLC and spectrophotometric properties. Among these pigments, pheophytins a and b showed relatively abundant amounts, and the second major group of the pigment was chlorophylls a and b, and carotenoids such as beta-carotene and lutein indicated lower concentrations. Although all these pigments exhibited significant antioxidant activities, the ranks of suppressive activity against hydroperoxide generation were chlorophyll a > lutein > pheophytin a > chlorophyll b > beta-carotene > pheophytin b. These results suggest that the non-polyphenolic fraction of residual green tea has a potent suppressive activity against hydroperoxide generation from oxidized linoleic acid, which is derived from the antioxidant activities of chlorophylls a and b, pheophytins a and b, beta-carotene and lutein. This finding also implies that the combined intake of polyphenols in water-soluble fraction and antioxidative pigments in the non-polyphenolic fraction of green tea will be more efficient to prevent life style-related chronic diseases.