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2.
Food Chem Toxicol ; 42(6): 983-93, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15110108

RESUMEN

We studied in vitro hormonal activity of bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE), which are used as a material of interior coating for food cans. We also examined related compounds such as 2,2-bis[4-(3-chloro-2-hydroxypropoxy)phenyl]propane (BADGE.2HCl), and bis[4-(3-chloro-2-hydroxypropoxy)phenyl]methane (BFDGE.2HCl) etc. For this purpose, we constructed two stably transfected CHO-K1 cell lines (AR-EcoScreen for androgenic activity and c-luc for cell toxicity evaluation). One stably expresses luciferase with induction of androgen. The other stably expresses luciferase without androgen induction. Also, we have determined the androgenic and anti-androgenic effects of the test chemicals by reporter gene assay with these cell lines. None of the chemicals tested by this assay exhibited androgen agonistic activity. However, BADGE.2HCl and BFDGE.2HCl had the conspicuous antagonistic activity for androgen. These compounds had a high binding affinity for androgen receptor. Furthermore, these two compounds did not show the estrogenic activity in vitro assays. On the contrary, bisphenol A and bisphenol F exhibited anti-androgenic activity in vitro in addition to the estrogenic activity. These results suggest that these chlorohydroxy compounds of BADGE and BFDGE act as androgen antagonist through the process of binding to androgen receptor.


Asunto(s)
Antagonistas de Andrógenos/farmacología , Carcinógenos/farmacología , Compuestos Epoxi/farmacología , Receptores Androgénicos/efectos de los fármacos , Animales , Compuestos de Bencidrilo , Células CHO , Cricetinae , Cricetulus , Femenino , Embalaje de Alimentos , Genes Reporteros , Transfección
3.
Food Chem Toxicol ; 40(7): 925-33, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12065214

RESUMEN

We orally administered polyphenone-60 (P-60), green tea extract catechins, in the diet (0, 1.25 and 5%) to male rats for 2, 4 and 8 weeks initiated at 5 weeks old. It was found that a 5% dose to male rats for 2-8 weeks induced goiters and decreased weights of the body, testis and prostate gland. Endocrinologically, elevating plasma thyroid stimulating hormone (TSH), luteinizing hormone (LH) and testosterone levels and decreasing tri-iodothyronine (T(3)) and thyroxine (T(4)) levels were induced by this treatment. We also found that P-60 as a whole and some of its constituents exhibited inhibitory effects on human placental aromatase activity by in vitro assay. The concentration of P-60 that required producing 50% inhibition of the aromatase activity (IC(50) value) was 28 microg/ml. The IC(50) values of (-)-catechin gallate (Cg), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCg) and (-)-gallocatechin gallate (GCg) were 5.5 x 10(-6), 1.0 x 10(-4), 6.0 x 10(-5) and 1.5 x 10(-5) M, respectively. (-)- Epicatechin gallate (ECg) at 1.0 x 10(-4) M produced 20% inhibition. (-)-Epicatechin (EC) and (+)-catechin (CT) exhibited no effects on aromatase activity. The endocrinological changes observed in vivo were in conformity with antithyroid effects and aromatase inhibition effects of P-60 and its constituents.


Asunto(s)
Inhibidores de la Aromatasa , Extractos Vegetales/farmacología , Té/química , Administración Oral , Animales , Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Masculino , Tamaño de los Órganos/efectos de los fármacos , Extractos Vegetales/administración & dosificación , Ratas , Ratas Endogámicas F344 , Testosterona/sangre , Hormonas Tiroideas/sangre , Tirotropina/sangre
4.
Biol Pharm Bull ; 24(11): 1258-62, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11725959

RESUMEN

To explore the physiological roles of sulfotransferases (SULTs) in extra-hepatic tissues, we examined the expression of eight SULT genes by reverse transcription (RT)-PCR in human cell lines that were established from various tissues. Expression levels of SULTs were low in neural cell lines such as NB-1 and GI-1, and high in epithelial cell lines, such as Caco-2 and BeWo. SULT1C2 expression was abundant in all cell types, whereas that of SULT1E1, SULTIBI or SULT2B1 was restricted to a specific cell type. SULT1C1, which can catalyze the sulfation of N-hydroxy-2-acetylaminofluorene, was expressed in Caco-2, BeWo and KB562. Induction of differentiation did not generally affect SULT expression, although that of SULT1C2 was reduced after differentiation of the neuroblastoma cell line, NB-1, was induced. The profile of SULT expression in the culture cells obtained here gives clues to understanding the physiological roles of SULT enzymes in extra-hepatic tissues or organs.


Asunto(s)
Células CACO-2/metabolismo , Células HL-60/metabolismo , Células K562/metabolismo , Sulfotransferasas/biosíntesis , Células CACO-2/citología , Diferenciación Celular/fisiología , Coriocarcinoma/enzimología , Neoplasias del Colon/enzimología , Dopamina/metabolismo , Femenino , Perfilación de la Expresión Génica , Células HL-60/citología , Humanos , Mucosa Intestinal/enzimología , Isoenzimas/biosíntesis , Isoenzimas/genética , Células K562/citología , Naftoles/metabolismo , Neuronas/citología , Neuronas/enzimología , Especificidad por Sustrato , Sulfotransferasas/sangre , Sulfotransferasas/genética , Neoplasias Uterinas/enzimología
5.
Environ Health Perspect ; 109(7): 699-703, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11485868

RESUMEN

To examine the estrogenic activities of styrene oligomers, we carried out cell proliferation assays with estrogen-sensitive MCF-7 cells and competitive binding assays to human estrogen receptor [alpha] (hER[alpha]). The styrene oligomers tested were 1,3-diphenyl propane (SD-1), 2,4-diphenyl-1-butene (SD-2), cis-1,2-diphenyl cyclobutane (SD-3), trans-1,2-diphenyl cyclobutane (SD-4), 2,4,6-triphenyl-1-hexene (ST-1), 1a-phenyl-4a-(1'-phenylethyl)tetralin (ST-2), 1a-phenyl-4e-(1'-phenylethyl)tetralin (ST-3), 1e-phenyl-4a-(1'-phenylethyl)tetralin (ST-4), 1e-phenyl-4e-(1'-phenylethyl)tetralin (ST-5), 1e,3e,5a-triphenylcyclohexane (ST-6), and 1e,3e,5e-triphenylcyclohexane (ST-7). In the MCF-7 cell proliferation assay, styrene trimers (ST-1, ST-3, ST-4, and ST-5) had the highest proliferative activities of the compounds tested. The relative potency of these chemicals was 0.0002-0.0015%, which was comparable with that of bisphenol A (0.0001-0.0025%), and their relative proliferative effect was 51-104%. Styrene dimers (SD-3 and SD-4) also significantly increased the cell yields. However, SD-1, SD-2, ST-2, ST-6, and ST-7 had insignificant proliferative activities. The competitive binding assay revealed the binding affinity of some styrene oligomers for hER[alpha]. The order of their binding potency for hER[alpha] was as follows: ST-4 > ST-2 > ST-3 > ST-5 > ST-1 > SD-3 > SD-4 > SD-2 > SD-1. ST-6 and ST-7 did not appear to bind to hER[alpha]. The present studies indicate that styrene dimers SD-3 and SD-4 and styrene trimers ST-1, ST-3, ST-4, and ST-5 have estrogenic activity on MCF-7 cells and binding affinity for hER[alpha]. These compounds might be endocrine disrupters.


Asunto(s)
Neoplasias de la Mama/patología , División Celular/efectos de los fármacos , Receptores de Estrógenos/fisiología , Estirenos/efectos adversos , Unión Competitiva , Relación Dosis-Respuesta a Droga , Receptor alfa de Estrógeno , Femenino , Humanos , Células Tumorales Cultivadas/efectos de los fármacos
6.
J Vet Med Sci ; 63(6): 675-8, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11459016

RESUMEN

Changes in the activities of serum cytokines and in acute phase response were observed in dairy cows with naturally occurring coliform mastitis. Seven cows with severe mastitis showed systemic and mammary inflammatory response throughout the observation period, and 11 cows with mild mastitis recovered and were able to be milked within 3 days of onset of mastitis. Serum interleukin (IL)-I and tumor necrosis factor (TNF) activities were higher in the severe group than in the mild group at the first appearance of symptoms. Elevated IL-1 activity was evident in the severe group throughout the observation period. Serum alpha-1-acidglycoprotein (alpha1AG) concentration began to rise with the beginning of mastitis in the severe group, and peaked at 9 days. Serum haptoglobin (Hp) concentrations peaked at 3 days, and decreased gradually after 3 days in the severe group. These results showed that there are dynamic changes in serum IL-1 activity and in serum alpha1AG and Hp concentrations in cows with severe coliform mastitis.


Asunto(s)
Reacción de Fase Aguda/veterinaria , Infecciones por Enterobacteriaceae/veterinaria , Enterobacteriaceae/crecimiento & desarrollo , Mastitis Bovina/inmunología , Proteínas de Fase Aguda/análisis , Proteínas de Fase Aguda/biosíntesis , Reacción de Fase Aguda/inmunología , Reacción de Fase Aguda/microbiología , Animales , Temperatura Corporal , Bovinos , Citocinas/biosíntesis , Citocinas/sangre , Infecciones por Enterobacteriaceae/inmunología , Infecciones por Enterobacteriaceae/microbiología , Femenino , Haptoglobinas/análisis , Haptoglobinas/biosíntesis , Recuento de Leucocitos/veterinaria , Mastitis Bovina/microbiología , Orosomucoide/análisis , Orosomucoide/biosíntesis , Recuento de Plaquetas/veterinaria , Pulso Arterial/veterinaria
7.
Yakugaku Zasshi ; 121(2): 173-8, 2001 Feb.
Artículo en Japonés | MEDLINE | ID: mdl-11218732

RESUMEN

We studied the effects of 17 kinds of Kampo-formulations prescribed for the treatment of peptic ulcer on H,K-ATPase activity. The activity was strongly inhibited by San-o-shashin-to ([symbol: see text], IC50 = 82 micrograms/ml), Bukuryo-in ([symbol: see text], IC50 = 110 micrograms/ml), Shakuyaku-kanzo-to ([symbol: see text], IC50 = 170 micrograms/ml), Hange-koboku-to ([symbol: see text], IC50 = 290 micrograms/ml), Dai-saiko-to ([symbol: see text], IC50 = 340 micrograms/ml), Irei-san ([symbol: see text], IC50 = 380 micrograms/ml) than other Kampo-formulations. Among the 17 kinds of crude drugs contained in these Kampo-formulation, Rhei Rhizoma, Coptidis Rhizoma, Glycyrrhiza Radix, Cinnamomi Cortex, and Poria have notable inhibitory effects (IC50 = 19-57 micrograms/ml). H,K-ATPase activity was inhibited by sennoside A (Rhei Rhizoma), sennoside B (Rhei Rhizoma), ergosterol (Poria), coptisine (Coptidis Rhizoma), glycyrrhizin (Glycyrrhiza Radix), glycyrrhetic acid (Glycyrrhiza Radix), gallic acid (Cinnamomi Cortex) in the 21 components of these crude drugs (IC50 = 1.6-7.9 x 10(-4) M). The inhibition of San-o-shashin-to and Bukuryo-in is considered to be mainly attributed to Rhei Rhizoma and Poria, respectively. The anti-gastric ulcer effects of San-o-shashin-to and Bukuryo-in may be ascribed to the inhibition of H,K-ATPase activity.


Asunto(s)
Antiulcerosos/farmacología , Medicamentos Herbarios Chinos/farmacología , Inhibidores de la Bomba de Protones , Antiulcerosos/química , Relación Dosis-Respuesta a Droga , Medicamentos Herbarios Chinos/química , Iones , Metales/análisis
9.
Biochem Pharmacol ; 59(7): 881-6, 2000 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-10718347

RESUMEN

Hinesol, a major component of the crude drug "So-jutsu" (Atractylodis Lanceae Rhizoma), strongly inhibited H+,K+-ATPase activity with a IC50 value of 5.8x10(-5) M. It also inhibited Na+,K+-ATPase, Mg2+-ATPase, Ca2+-ATPase, and H+-ATPase activities, although the inhibition rate was lower. No effects on alkaline or acid phosphatase activities were observed. The mechanism by which hinesol inhibited H+,K+-ATPase activity was studied in detail. The inhibition was uncompetitive with respect to ATP, and it increased as the Mg2+ concentration was raised, whereas it was not affected by the K+ concentration. The activity of K+-dependent p-nitrophenyl phosphatase (K+-pNPPase), a partial reaction of H+,K+-ATPase, was inhibited by hinesol noncompetitively with respect to pNPP (IC50 value of 1.6x10(-4) M), and competitively with respect to K+, whereas it was not affected by the Mg2+ concentration. These results suggest that hinesol is a relatively specific inhibitor of H+,K+-ATPase. It appears that hinesol reacts with enzyme in the E1 state in the presence of ATP and Mg2+ and forms the complex hinesol-H+ E1-ATP or hinesol x E1-P, blocking the conformational change to the E2 state. Furthermore, hinesol enhanced the inhibitory effect of omeprazole on H+,K+-ATPase, and the inhibitory site of hinesol was different from that of omeprazole. The effect of So-jutsu as an anti-gastric ulcer agent may be ascribed to the inhibitory effect of hinesol on H+,K+-ATPase activity.


Asunto(s)
Medicamentos Herbarios Chinos/química , Inhibidores Enzimáticos/farmacología , Inhibidores de la Bomba de Protones , Compuestos de Espiro/farmacología , 4-Nitrofenilfosfatasa/antagonistas & inhibidores , 4-Nitrofenilfosfatasa/metabolismo , Adenosina Trifosfatasas/antagonistas & inhibidores , Adenosina Trifosfatasas/metabolismo , Animales , Técnicas In Vitro , Ligandos , Medicina Tradicional China , Omeprazol/farmacología , Monoéster Fosfórico Hidrolasas/antagonistas & inhibidores , Monoéster Fosfórico Hidrolasas/metabolismo , Sesquiterpenos , Porcinos
10.
Biol Pharm Bull ; 23(2): 199-203, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10706384

RESUMEN

Moutan Cortex (root cortex of Paeonia suffruticosa ANDREWS) and Paeoniae Radix (root of Paeonia lactiflora PALLAS) are crude drugs used in many traditional prescriptions and have constituents in common. We studied the effects of extracts of these crude drugs and their constituents on oxidative DNA damage caused by phenylhydroquinone (PHQ), a major metabolite of o-phenylphenol. Both drugs suppressed the cleavage of pUC18 DNA induced by PHQ, and scavenged the superoxide and hydroxy radical generated by the chemical. They also inhibited the oxidative DNA cleavage by tert-butylhydroquinone (TBHQ), one of the major metabolites of butylated hydroxyanisole. When constituents were examined with the same system, galloylpaeoniflorin and 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) were found to be the most potent inhibitors of the DNA cleavage. These constituents had oxygen radical scavenging activity. Paeonol also attenuated the DNA cleavage. Paeoniflorin and albiflorin had relatively small inhibitory effects on DNA cleavage. However, catechin enhanced the PHQ-induced DNA cleavage. The suppression of oxidative DNA damage by Moutan Cortex and Paeoniae Radix might be attributable to the additive effects of galloylpaeoniflorin, PGG and other constituents.


Asunto(s)
Compuestos de Bifenilo/antagonistas & inhibidores , Daño del ADN/efectos de los fármacos , Hidroquinonas/antagonistas & inhibidores , Plantas Medicinales/química , Compuestos de Bifenilo/farmacología , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Grupo Citocromo c/antagonistas & inhibidores , Grupo Citocromo c/metabolismo , Espectroscopía de Resonancia por Spin del Electrón , Depuradores de Radicales Libres/farmacología , Hidroquinonas/química , Hidroquinonas/farmacología , Oxidación-Reducción , Raíces de Plantas/química , Especies Reactivas de Oxígeno , Superóxidos/química
11.
Yakugaku Zasshi ; 120(12): 1429-33, 2000 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-11193391

RESUMEN

Alkyl p-hydroxybenzoates such as isobutyl p-hydroxybenzoate (PHBA-iBu), butyl p-hydroxybenzoate (PHBA-nBu), isopropyl p-hydroxybenzoate (PHBA-iPr), propyl p-hydroxybenzoate (PHBA-nPr), ethyl p-hydroxybenzoate (PHBA-Et), and methyl p-hydroxybenzoate (PHBA-Me) are widely used as preservatives, stabilizers and antiseptics for medical supplies, cosmetics, foodstuffs etc. We determined the binding affinity of alkyl p-hydroxybenzoates to human estrogen receptor alpha (ER alpha) and beta (ER beta) by non-RI receptor binding assays. PHBA-iBu had a high binding affinity for ER alpha (IC50: 6.0 x 10(-6) M, the relative binding affinity (RBA): 0.267) and ER beta (IC50: 5.0 x 10(-6) M, RBA: 0.340). These IC50 values and RBA were almost the same as those of bisphenol A. The ranking of the estrogenic potency of alkyl p-hydroxybenzoates for both ERs is different; that is, PHBA-iBu > PHBA-nBu[symbol: see text]PHBA-iPr[symbol: see text]PHBA-nPr > PHBA-Et >> PHBA-Me. Alkyl p-hydroxybenzoates bound with equal relative affinity to both ER alpha and beta proteins. Alkyl p-hydroxybenzoate having a long alkyl side-chain showed a high affinity for ER alpha and beta. These findings suggest that p-hydroxybenzoates may be endocrine disruptors.


Asunto(s)
Unión Competitiva , Parabenos/metabolismo , Receptores de Estrógenos/metabolismo , Receptor alfa de Estrógeno , Receptor beta de Estrógeno , Humanos , Parabenos/química , Relación Estructura-Actividad
12.
Biol Pharm Bull ; 22(11): 1180-4, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10598024

RESUMEN

We examined the effects of Bu-Zhong-Yi-Qi-Tang (Japanese name: Hochu-ekki-to, HET), a traditional Chinese medicine, on IgE production and histamine release in mice immunized intraperitoneally with a mixture of ovalbumin (OA) and aluminum hydroxide (alum adjuvant). Three groups of mice were orally administered 0, 1.7 or 17 mg of HET on day 13 after the first immunization with a mixture of 1 microg OA and 1 mg alum adjuvant. They were again immunized with the same dose of OA plus alum adjuvant on day 14. The immunological changes in mice treated with OA alone or OA plus HET were examined, and the following findings were obtained. In the HET-treated mice, the elevation of anti-OA IgE in serum, and histamine release from basophils in blood, were significantly suppressed. A significant suppression of interleukin-4 (IL-4) secretion and proliferation of splenic lymphocytes in primary culture was also observed. A tendency to suppress the elevation of anti-OA IgG1 in serum and interleukin-2 (IL-2) secretion from splenic lymphocytes was observed in the HET-treated mice. These findings suggest that oral administration of HET suppresses IgE antibody production and histamine release in type I allergic reaction in mice immunized with OA plus alum adjuvant; this shows the efficacy of HET in treating type I allergic diseases, such as asthma.


Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Liberación de Histamina/efectos de los fármacos , Inmunoglobulina E/biosíntesis , Ovalbúmina/inmunología , Animales , Basófilos/efectos de los fármacos , Basófilos/inmunología , Basófilos/metabolismo , División Celular/efectos de los fármacos , Femenino , Inmunización , Interleucina-2/biosíntesis , Interleucina-4/biosíntesis , Linfocitos/efectos de los fármacos , Linfocitos/inmunología , Masculino , Ratones , Ratas , Ratas Wistar , Bazo/citología , Bazo/efectos de los fármacos , Bazo/metabolismo
14.
Chem Biol Interact ; 109(1-3): 69-80, 1998 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-9566734

RESUMEN

Rat hydroxysteroid sulfotransferase (HS-SULT) cDNAs, ST-40 and ST-20 are 90% identical in amino acid sequences and show different substrate specificities toward dehydroepiandrosterone (DHEA), androsterone (AD) and cortisol (CS). ST-40 enzyme is active toward the three substrates, whereas ST-20 enzyme is preferentially active for CS. First we prepared mutants of well conserved histidine, lysine and asparagine by site-directed mutagenesis. Secondly we constructed 20 chimeric HS-SULTs by reciprocal exchange of five protein domains between ST-20 and ST-40 enzymes. The studies on the expressed mutant and chimeric enzymes indicate the importance of the C-terminal region for the substrate specificity and the involvement of multiple regions for the enzyme activities. Next we determined the genetic loci of ST-40 and ST-20 by fluorescence in situ hybridization. Biotinylated ST-20 and ST-40 probes gave a pair of fluorescent spots on the same region of rat chromosome 1 and the loci of these genes were localized to the same chromosomal region of 1q21.3 --> q22.1. Finally we studied mouse olfactory phenol SULT (P-SULT). It was immunolocalized in the cytoplasm of mouse olfactory sustentacular cells and mouse nasal cytosols show high SULT activities toward phenolic aromatic odorants. We subsequently isolated a mouse P-SULT cDNA from mouse olfactory cDNA library. It encodes 304 amino acid polypeptide and is 94% identical with rat ST1C1 in amino acid sequences.


Asunto(s)
Arilsulfotransferasa/genética , Hígado/enzimología , Vías Olfatorias/enzimología , Sulfotransferasas/genética , Secuencia de Aminoácidos , Animales , ADN Complementario/genética , Ratones , Datos de Secuencia Molecular , Ratas , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Homología de Secuencia de Aminoácido
15.
Cancer Lett ; 122(1-2): 9-15, 1998 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-9464485

RESUMEN

DNA damage caused by tamoxifen and its derivatives was examined by estimating the conversion of supercoiled pUC18 plasmid DNA to linear form by means of agarose gel electrophoresis. N-Desmethyltamoxifen induced DNA cleavage and its effect was enhanced by the addition of reducing agents such as dithiothreitol, NADPH and 2-mercaptoethanol. 4-Hydroxytamoxifen itself had little effect, but the cleavage was slightly enhanced by the addition of reducing agents. DNA damage was higher with alpha-hydroxytoremifene than with alpha-hydroxytamoxifen, which had a prominent effect only at high concentration. The cleavage by alpha-hydroxy derivatives were not enhanced by reducing agents. No damage was induced by tamoxifen, toremifene, 3-hydroxytamoxifen or N-desmethyltoremifene. The DNA cleavage by N-desmethyltamoxifen was inhibited by the addition of EDTA, mannitol, sodium azide, methionine, catalase and superoxide dismutase. The formation of 8-hydroxy-2'-deoxyguanosine was also examined with calf thymus DNA in vitro. A slight increase of its level was found with 4-hydroxytamoxifen in the presence of dithiothreitol and also with N-desmethyltamoxifen in the presence of NADPH, but alpha-hydroxytoremifene and alpha-hydroxytamoxifen were ineffective. These experimental data suggest that among metabolites of tamoxifen, N-desmethyltamoxifen and probably also 4-hydroxytamoxifen cause oxidative DNA damage in which redox cycling is involved. The DNA damage by alpha-hydroxytoremifene appears to involve a different mechanism from that by N-desmethyltamoxifen. Tamoxifen and toremifene are possibly metabolized to the forms contributing to DNA damage.


Asunto(s)
Daño del ADN , ADN/efectos de los fármacos , Desoxiguanosina/análogos & derivados , Antagonistas de Estrógenos/toxicidad , Tamoxifeno/toxicidad , 8-Hidroxi-2'-Desoxicoguanosina , Animales , Bovinos , Aductos de ADN/metabolismo , Desoxiguanosina/metabolismo
16.
FEBS Lett ; 412(1): 153-6, 1997 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-9257710

RESUMEN

Treatment of U937 cells with dolichyl phosphate led to an increase in the activity of the ICE family protease CPP32, accompanied with cleavage of pre-CPP32 to generate p17. Peptide inhibitors YVAD-cmk and Z-Asp-CH2-DCB (specific to ICE) and DEVD-CHO (specific to CPP32) blocked the dolichyl phosphate-induced apoptosis. The dolichyl phosphate-induced increase of CPP32 activity was inhibited by adenylate cyclase inhibitors, SQ 22536 and 2',5'-dideoxyadenosine. Dolichyl phosphate caused a transient increase of intracellular cAMP concentration. The results suggest that modulation of cAMP synthesis due to the stimulation of adenylate cyclase by dolichyl phosphate plays a critical role in CPP32 activation and apoptosis.


Asunto(s)
Apoptosis , Caspasas , Cisteína Endopeptidasas/metabolismo , Fosfatos de Dolicol/farmacología , Leucemia Monocítica Aguda/enzimología , Adenina/análogos & derivados , Adenina/farmacología , Inhibidores de Adenilato Ciclasa , Adenilil Ciclasas/metabolismo , Caspasa 3 , AMP Cíclico/metabolismo , Fragmentación del ADN , Didesoxiadenosina/análogos & derivados , Didesoxiadenosina/farmacología , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/metabolismo , Humanos , Cinética , Células Tumorales Cultivadas
17.
Biochem Pharmacol ; 53(4): 611-4, 1997 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-9105414

RESUMEN

The inhibition of Na+,K(+)-ATPase activity by various constituents of Moutan Cortex and Paeoniae Radix was studied. 1,2,3,4,6-Penta-O-galloyl-beta-D-glucose (PGG), a major component of both crude drugs, strongly inhibited Na+,K(+)-ATPase activity (IC50 = 2.5 x 10(-6) M), whereas galloylpaeoniflorin, benzoic acid, and catechin were weakly inhibitory, and albiflorin, oxypaeoniflorin, paeoniflorin, paconol, and phenol were ineffective. The inhibition of Na+,K(+)-ATPase activity by PGG was decreased in the presence of BSA or phospholipids. The inhibition mode of PGG was noncompetitive with respect to ATP. The K0.5 value for Na+ was increased by the addition of PGG from 9.1 to 12.3 mM, whereas that for K+ was not altered. PGG also inhibited K(+)-dependent p-nitrophenyl phosphatase activity with an IC50 value of 5.3 x 10(-6) M, and the extent of the inhibition increased at higher concentrations of K+. The K0.5 value for K+ was decreased by the addition of PGG from 3.3 to 2.0 mM. These results suggested that the inhibition of Na+,K(+)-ATPase activity is caused by interaction of PGG with the enzyme in the E2 state. The inhibitory effect of Moutan Cortex or Paeoniae Radix is considered to be mainly attributable to PGG.


Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Inhibidores Enzimáticos/farmacología , Taninos Hidrolizables , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Taninos/farmacología , 4-Nitrofenilfosfatasa/antagonistas & inhibidores , Animales , Relación Dosis-Respuesta a Droga , Caballos
18.
Toxicol Lett ; 90(1): 11-8, 1997 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-9020397

RESUMEN

The effects of synthetic phenolic antioxidants, tert-butylhydroquinone (TBHQ), 2,5-di-tert-butylhydroquinone (DTBHQ) and 3-tert-butyl-4-hydroxyanisole (BHA), on DNA cleavage were examined with supercoiled plasmid DNA, pUC18, in vitro. Extensive single and double strand breaks of DNA by TBHQ were observed and almost all the DNA was converted to the linear form at 10(-2) M. The cleavage was stimulated by both CuCl2 and FeCl2, though the effect of FeCl2 was smaller. Metal ion chelators and some oxygen radical scavengers inhibited the cleavage. The generation of TBHQ semiquinone radical and hydroxyl radical in the presence of copper was demonstrated by ESR spectroscopy. DTBHQ also caused DNA cleavage, though its effect was much smaller than that of TBHQ. BHA had no effect in the experimental systems employed. Oxygen radicals were considered to contribute to the DNA cleavage by TBHQ and DTBHQ.


Asunto(s)
Antioxidantes/metabolismo , Daño del ADN/efectos de los fármacos , Hidroquinonas/metabolismo , Quinonas/toxicidad , Especies Reactivas de Oxígeno/metabolismo , Animales , Hidroxianisol Butilado/metabolismo , Cobre/farmacología , Cricetinae , Compuestos Ferrosos/farmacología , Radicales Libres/antagonistas & inhibidores , Radicales Libres/metabolismo , Radicales Libres/toxicidad , Mesocricetus , Quinonas/síntesis química
19.
Toxicol Lett ; 89(2): 163-7, 1996 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-8960159

RESUMEN

Oxidative DNA damage caused by butylated hydroxyanisole (BHA), 2-tert-butyl(1,4)hydroquinone (TBHQ, a metabolite of BHA) and 2,5-di-tert-butyl(1,4)hydroquinone (DTBHQ), as well as 2,6-di-tert-butyl(1,4)benzoquinone (BHTQ, a metabolite of butylated hydroxytoluene), was evaluated by measuring the formation of 8-hydroxydeoxyguanosine (8OHdG) in calf thymus DNA. 8OHdG formation was greatly increased by TBHQ in a concentration-dependent manner. This effect was strongly enhanced by CuCl2 and suppressed by EDTA, bathocuproinedisulfonic acid disodium salt, methionine, glutathione reduced form or catalase, but was not affected by mannitol, sodium benzoate or sodium azide. Thus, TBHQ-induced 8OHdG formation may be mediated by copper. DTBHQ also induced the formation of 8OHdG, though to a much lesser extent than TBHQ, and its effect was stimulated by CuCl2. BHA had a small enhancing effect at high concentration, only in the presence of CuCl2, whereas in the case of BHTQ, it occurred both in the presence of CuCl2 and FeCl2.


Asunto(s)
Antioxidantes/química , Hidroxianisol Butilado/química , Daño del ADN , ADN/química , Desoxiguanosina/análogos & derivados , Hidroquinonas/química , 8-Hidroxi-2'-Desoxicoguanosina , Animales , Hidroxianisol Butilado/metabolismo , Bovinos , Desoxiguanosina/análisis , Desoxiguanosina/química , Timo/química
20.
Biochem Pharmacol ; 51(3): 339-43, 1996 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-8573201

RESUMEN

Atractylon, a major component of the crude drug "Byaku-jutsu" (rhizomes of Atractylodes japonica), strongly inhibited Na+,K(+)-ATPase activity with an I50 value of 8.9 x 10(-6) M. It also inhibited Mg(2+)-ATPase, H+,K(+)-ATPase, H(+)-ATPase and Ca(2+)-ATPase activities, but less potently. No effects on alkaline and acid phosphatase activities were observed. The inhibition of Na+,K(+)-ATPase activity by atractylon was noncompetitive with respect to ATP and was greater with increasing K+ concentration, whereas it was not affected by Na+ concentration. The activity of K(+)-dependent p-nitrophenyl phosphatase, a partial reaction of Na+,K(+)-ATPase, was inhibited noncompetitively with respect to substrate (I50 value of 1.8 x 10(-5) M), and the inhibition rate was independent of the K+ concentration. Furthermore, atractylon increased the Ki value for Na+ from 130 to 190 mM, but did not alter the Ki value for ATP. Inhibition of the phosphoenzyme formation by atractylon was greater at 0.1 M than at 1 M NaCl. K(+)-dependent dephosphorylation (E2-P to K.E2) was inhibited by atractylon, whereas ADP-sensitive (Na.E1-P to Na.E1) and non-specific dephosphorylation steps were not affected. These results suggest that atractylon, a specific inhibitor of Na+,K(+)-ATPase, interacts with enzyme in the E2 state and inhibits the reaction step from E2-P to K.E2.


Asunto(s)
Plantas Medicinales , Sesquiterpenos/farmacología , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , 4-Nitrofenilfosfatasa/antagonistas & inhibidores , Animales , Mucosa Gástrica/enzimología , Caballos , Riñón/enzimología , Medicina Tradicional China , Fosforilación/efectos de los fármacos , Cloruro de Potasio/farmacología , Ratas , Cloruro de Sodio/farmacología , ATPasa Intercambiadora de Sodio-Potasio/aislamiento & purificación
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