Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Front Immunol ; 10: 1737, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31417547

RESUMEN

The gut microbiota influences several biological functions including immune responses. Inflammatory bowel disease is favorably influenced by consumption of several dietary natural plant products such as pomegranate, walnuts, and berries containing polyphenolic compounds such as ellagitannins and ellagic acid. The gut microbiota metabolizes ellagic acid resulting in the formation of bioactive urolithins A, B, C, and D. Urolithin A (UA) is the most active and effective gut metabolite and acts as a potent anti-inflammatory and anti-oxidant agent. However, whether gut metabolite UA affects the function of immune cells remains incompletely understood. T cell proliferation is stimulated by store operated Ca2+ entry (SOCE) resulting from stimulation of Orai1 by STIM1/STIM2. We show here that treatment of murine CD4+ T cells with UA (10 µM, 3 days) significantly blunted SOCE in CD4+ T cells, an effect paralleled by significant downregulation of Orai1 and STIM1/2 transcript levels and protein abundance. UA treatment further increased miR-10a-5p abundance in CD4+ T cells in a dose dependent fashion. Overexpression of miR-10a-5p significantly decreased STIM1/2 and Orai1 mRNA and protein levels as well as SOCE in CD4+ T cells. UA further decreased CD4+ T cell proliferation. Thus, the gut bacterial metabolite UA increases miR-10a-5p levels thereby downregulating Orai1/STIM1/STIM2 expression, store operated Ca2+ entry, and proliferation of murine CD4+ T cells.


Asunto(s)
Bacterias/inmunología , Linfocitos T CD4-Positivos/inmunología , Señalización del Calcio/inmunología , Calcio/inmunología , Cumarinas/inmunología , Microbioma Gastrointestinal/inmunología , MicroARNs/inmunología , Animales , Proliferación Celular , Femenino , Regulación de la Expresión Génica/inmunología , Masculino , Ratones , Proteína ORAI1/inmunología , Molécula de Interacción Estromal 1/inmunología , Molécula de Interacción Estromal 2/inmunología
2.
FASEB J ; 29(6): 2347-58, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25713031

RESUMEN

Catalytic antibodies have exhibited interesting functions against some infectious viruses such as HIV, rabies virus, and influenza virus in vitro as well as in vivo. In some cases, a catalytic antibody light chain takes on several structures from the standpoint of molecular size (monomer, dimer, etc.) and/or isoelectronic point. In this study, we prepared a monomeric 23D4 light chain by mutating the C-terminal Cys to Ala of the wild-type. The mutated 23D4 molecule took a simple monomeric form, which could hydrolyze synthetic 4-methyl-coumaryl-7-amide substrates and a plasmid DNA. Because the monomeric 23D4 light chain suppressed the infection of influenza virus A/Hiroshima/37/2001 in an in vitro assay, the corresponding experiments were conducted in vivo, after the virus strain (which was taken from a human patient) was successfully adapted into BALB/cN Sea mice. In the experiments, a mixture of the monomeric 23D4 and the virus was nasally administered 1) with preincubation and 2) without preincubation. As a result, the monomeric 23D4 clearly exhibited the ability to suppress the influenza virus infection in both cases, indicating a potential drug for preventing infection of the influenza A virus.


Asunto(s)
Anticuerpos Catalíticos/inmunología , Antivirales/inmunología , Cadenas Ligeras de Inmunoglobulina/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Infecciones por Orthomyxoviridae/inmunología , Animales , Anticuerpos Catalíticos/genética , Anticuerpos Catalíticos/metabolismo , Antivirales/metabolismo , Antivirales/farmacología , Western Blotting , Cumarinas/inmunología , Cumarinas/metabolismo , Interacciones Huésped-Patógeno/efectos de los fármacos , Interacciones Huésped-Patógeno/inmunología , Humanos , Cadenas Ligeras de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/metabolismo , Subtipo H1N1 del Virus de la Influenza A/fisiología , Ratones Endogámicos BALB C , Microscopía de Fuerza Atómica , Mutación , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/virología , Especificidad por Sustrato
3.
Peptides ; 68: 105-12, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25579437

RESUMEN

Apolipophorin III (apoLp-III), a lipid-binding protein and an insect homolog of human apolipoprotein E, plays an important role in lipid transport and immune response in insects. In the present study, we have demonstrated a correlation in time between changes in the apoLp-III abundance occurring in the hemolymph, hemocytes, and fat body after immunization of Galleria mellonella larvae with Gram-negative bacteria Escherichia coli, Gram-positive bacteria Micrococcus luteus, yeast Candida albicans, and a filamentous fungus Fusarium oxysporum. Using two-dimensional electrophoresis (IEF/SDS-PAGE) and immunoblotting with anti-apoLp-III antibodies, the profile of apoLp-III forms in G. mellonella larvae challenged with the bacteria and fungi has been analyzed. Besides the major apoLp-III protein (pI=6.5), one and three additional apoLp-III forms differing in the pI value have been detected, respectively, in the hemolymph, hemocytes, and fat body of non-immunized insects. Also, evidence has been provided that particular apoLp-III-derived polypeptides appear after the immune challenge and are present mainly in the hemolymph and hemocytes. The time of their appearance and persistence in the hemolymph was dependent on the pathogen used. At least two of the apoLp-III forms detected in hemolymph bound to the microbial cell surface. The increasing number of hemolymph apoLp-III polypeptides and differences in their profiles observed in time after the challenge with different immunogens confirmed the important role of apoLp-III in discriminating between pathogens by the insect defense system and in antibacterial as well as antifungal immune response.


Asunto(s)
Apolipoproteínas/sangre , Proteínas de Insectos/sangre , Mariposas Nocturnas/metabolismo , Animales , Candida albicans/inmunología , Cumarinas/inmunología , Escherichia coli/inmunología , Cuerpo Adiposo/metabolismo , Hemolinfa/metabolismo , Inmunidad Innata , Larva/inmunología , Larva/metabolismo , Larva/microbiología , Micrococcus luteus/inmunología , Mariposas Nocturnas/inmunología , Mariposas Nocturnas/microbiología , Especificidad de Órganos , Isoformas de Proteínas/sangre
4.
PLoS One ; 9(5): e96502, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24800925

RESUMEN

Daphnetin, a plant-derived dihydroxylated derivative of coumarin, is an effective compound extracted from a plant called Daphne Korean Nakai. Coumarin derivates were known for their antithrombotic, anti-inflammatory, and antioxidant activities. The present study was aimed to determine the immunosuppressive effects and the underlying mechanisms of daphnetin on concanavalin A (ConA) induced T lymphocytes in mice. We showed that, in vitro, daphnetin suppressed ConA-induced splenocyte proliferation, influenced production of the cytokines and inhibited cell cycle progression through the G0/G1 transition. The data also revealed that daphnetin could down-regulate activation of ConA induced NF-κB and NFAT signal transduction pathways in mouse T lymphocyte. In vivo, daphnetin treatment significantly inhibited the 2, 4- dinitrofluorobenzene (DNFB) -induced delayed type hypersensitivity (DTH) reactions in mice. Collectively, daphnetin had strong immunosuppressive activity both in vitro and in vivo, suggesting a potential role for daphnetin as an immunosuppressive agent, and established the groundwork for further research on daphnetin.


Asunto(s)
Cumarinas/inmunología , Inmunosupresores/inmunología , FN-kappa B/inmunología , Factores de Transcripción NFATC/inmunología , Transducción de Señal/inmunología , Linfocitos T/inmunología , Umbeliferonas/inmunología , Animales , Proliferación Celular/efectos de los fármacos , Concanavalina A/inmunología , Cumarinas/farmacología , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/inmunología , Fase G1/efectos de los fármacos , Fase G1/inmunología , Hipersensibilidad Tardía/inmunología , Inmunosupresores/farmacología , Masculino , Ratones , Ratones Endogámicos BALB C , Fase de Descanso del Ciclo Celular/efectos de los fármacos , Fase de Descanso del Ciclo Celular/inmunología , Transducción de Señal/efectos de los fármacos , Linfocitos T/efectos de los fármacos , Umbeliferonas/farmacología
5.
J Agric Food Chem ; 60(36): 8866-76, 2012 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-22463485

RESUMEN

Pomegranate ellagitannins (ETs) are transformed in the gut to ellagic acid (EA) and its microbiota metabolites, urolithin A (Uro-A) and urolithin B (Uro-B). These compounds exert anti-inflammatory effects in vitro and in vivo. The aim of this study was to investigate the effects of Uro-A, Uro-B, and EA on colon fibroblasts, cells that play a key role in intestinal inflammation. CCD18-Co colon fibroblasts were exposed to a mixture of Uro-A, Uro-B, and EA, at concentrations comparable to those found in the colon (40 µM Uro-A, 5 µM Uro-B, 1 µM EA), both in the presence or in the absence of IL-1ß (1 ng/mL) or TNF-α (50 ng/mL), and the effects on fibroblast migration and monocyte adhesion were determined. The levels of several growth factors and adhesion cytokines were also measured. The mixture of metabolites significantly inhibited colon fibroblast migration (∼70%) and monocyte adhesion to fibroblasts (∼50%). These effects were concomitant with a significant down-regulation of the levels of PGE(2), PAI-1, and IL-8, as well as other key regulators of cell migration and adhesion. Of the three metabolites tested, Uro-A exhibited the most significant anti-inflammatory effects. The results show that a combination of the ET metabolites found in colon, urolithins and EA, at concentrations achievable in the intestine after the consumption of pomegranate, was able to moderately improve the inflammatory response of colon fibroblasts and suggest that consumption of ET-containing foods has potential beneficial effects on gut inflammatory diseases.


Asunto(s)
Antiinflamatorios/inmunología , Colon/inmunología , Cumarinas/inmunología , Ácido Elágico/inmunología , Fibroblastos/inmunología , Taninos Hidrolizables/metabolismo , Inflamación/inmunología , Extractos Vegetales/metabolismo , Antiinflamatorios/metabolismo , Biomarcadores/metabolismo , Biotransformación , Línea Celular , Movimiento Celular , Cumarinas/metabolismo , Ácido Elágico/metabolismo , Fibroblastos/citología , Humanos , Inflamación/tratamiento farmacológico , Inflamación/genética , Interleucina-1beta/inmunología , Interleucina-8/genética , Interleucina-8/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/inmunología , Lythraceae/química , Inhibidor 1 de Activador Plasminogénico/genética , Inhibidor 1 de Activador Plasminogénico/metabolismo , Factor de Necrosis Tumoral alfa/inmunología
7.
Contact Dermatitis ; 57(6): 361-4, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17988284

RESUMEN

BACKGROUND: There is controversy as to whether coumarin, an ingredient in cosmetics and fragrances, is a contact allergen involved in fragrance allergy. We recently showed that the purity of coumarin is a critical parameter for its allergenicity because coumarin preparations containing trace amounts of contaminants induced cell proliferation in the local lymph node (LN) assay whereas pure coumarin did not. OBJECTIVE/METHOD: In the present study, we analyzed the sensitizing properties of coumarin (purity > 99.9) and of dihydrocoumarin (DHC), in a recently developed model of fragrance allergy in mice. RESULTS: DHC was able to prime T cells in LNs draining the sensitization skin site and to induce a typical allergic contact dermatitis (ACD) reaction upon challenge, confirming that DHC is endowed with moderate sensitizing properties. In contrast, no T-cell activation and no ACD responses were obtained following sensitization and challenge with coumarin. CONCLUSION: These results confirm that pure coumarin is endowed with very weak sensitizing capacities, if any, and suggest that the presence of contaminants in coumarin preparations may account for the previously reported allergenic properties of coumarin.


Asunto(s)
Cumarinas/efectos adversos , Dermatitis Alérgica por Contacto/etiología , Perfumes/efectos adversos , Animales , Antígenos CD4/inmunología , Cumarinas/inmunología , Dermatitis Alérgica por Contacto/inmunología , Oído/patología , Ensayo de Inmunoadsorción Enzimática , Interferón gamma/metabolismo , Ensayo del Nódulo Linfático Local , Depleción Linfocítica , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Linfocitos T/inmunología , Linfocitos T/metabolismo
8.
Microbes Infect ; 9(1): 7-14, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17196418

RESUMEN

Coumarin and its derivatives are naturally occurring substances with multiple biological activities. Here we demonstrate that prophylactic peroral administration of coumarin or 7-hydroxycoumarin (7-OHC) enhances resistance to subsequent lethal Salmonella enterica Serovar Typhimurium infection in mice. 7-OHC decreased bacterial load in liver and spleen, and enhanced phagocytosis and bacterial killing by macrophages when applied in vitro and in vivo. 7-OHC treatment induced significant NO release in peritoneal macrophage cultures. The observed protective effect correlated with the induction of Th1-associated cytokines, such as IL-12, IFN-gamma, and TNF-alpha. These data demonstrate a clear immunomodulatory potential of coumarins which might have important therapeutic implications to enhance resistance to infection.


Asunto(s)
Cumarinas/farmacología , Salmonella typhi/aislamiento & purificación , Fiebre Tifoidea/inmunología , Umbeliferonas/farmacología , Animales , Cumarinas/sangre , Cumarinas/inmunología , Interferón gamma/inmunología , Interleucina-12/inmunología , Hígado/efectos de los fármacos , Hígado/inmunología , Hígado/microbiología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/microbiología , Ratones , Ratones Endogámicos BALB C , Monocitos/efectos de los fármacos , Monocitos/inmunología , Neutrófilos/efectos de los fármacos , Neutrófilos/inmunología , Fagocitosis/efectos de los fármacos , Fagocitosis/inmunología , Especies de Nitrógeno Reactivo/metabolismo , Salmonella typhi/inmunología , Bazo/efectos de los fármacos , Bazo/inmunología , Bazo/microbiología , Células TH1/efectos de los fármacos , Células TH1/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Fiebre Tifoidea/microbiología , Fiebre Tifoidea/prevención & control , Umbeliferonas/sangre , Umbeliferonas/inmunología
9.
Int Arch Allergy Immunol ; 140(3): 231-8, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16685137

RESUMEN

BACKGROUND/AIMS: Positive patch tests are considered representative of a contact allergy to the tested chemical. However, contaminants and derivatives rather than the suspected chemical itself could be responsible for the allergic skin reactions. Here, we tested the importance of contaminants in the sensitizing and allergenic properties of coumarin in mice and humans. Coumarin, an ingredient in cosmetics and fragrances, was chosen as the reference chemical since conflicting results have been obtained regarding its ability to induce contact allergy. In some chemical preparations, this could be explained by the presence of coumarin derivatives endowed with allergenic properties. METHODS: In mice, three different coumarin preparations were tested in the local lymph node assay. In humans, we assessed the irritant and allergenic properties of highly pure coumarin in nonallergic and fragrance-allergic patients. RESULTS: Pure coumarin did not exhibit irritant or sensitizing properties in the local lymph node assay. In contrast, two other commercially available coumarins and three contaminants that were detected in these coumarin preparations were identified as weak and moderate sensitizers, respectively. In humans, pure coumarin was extremely well tolerated since only 1 out of 512 patients exhibited a positive patch test to the chemical. CONCLUSIONS: These results indicate that coumarin cannot be considered as a common contact allergen and further emphasize that purity of chemicals is mandatory for the assessment of their allergenicity.


Asunto(s)
Cumarinas/química , Dermatitis Alérgica por Contacto/etiología , Adulto , Anciano , Animales , Cumarinas/inmunología , Dermatitis Alérgica por Contacto/diagnóstico , Dermatitis Alérgica por Contacto/inmunología , Contaminación de Medicamentos , Femenino , Humanos , Irritantes/química , Irritantes/inmunología , Ensayo del Nódulo Linfático Local , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos CBA , Persona de Mediana Edad , Pruebas del Parche , Perfumes/química , Perfumes/farmacología
10.
Yakugaku Zasshi ; 121(1): 97-103, 2001 Jan.
Artículo en Japonés | MEDLINE | ID: mdl-11201168

RESUMEN

The contact sensitization of 11 simple coumarins was examined by subcutaneous sensitizing of guinea pigs, and the structure-activity relationship and cross-reactivity were investigated. Esculetin, 4-methylesculetin, and dephnetin were found to be strong sensitizers, and 4-hydroxy-coumarin to be a moderate sensitizer. Other simple coumarins tested had a weak sensitivity to mild sensitizers. The results suggest that the introduction of hydroxy group, especially adjacent substitution at the 6, 7, and 8 positions of the coumarin ring with two hydroxy groups, may play an important role in exhibiting the contact sensitization activity. The cross-reactivity was observed between esculetin and 4-methylesculetin, esculin or isoscoporetin, and also between daphnetin and 4-methylumbelliferone or umbelliferone, although there was no mutual cross-reactivity between esculetin and daphnetin. It is interesting to note that guinea pigs, which had a weak sensitivity to umbelliferone, showed a strong cross-reactivity to daphnetin, while those, which had a weak sensitivity to daphnetin, showed a weak cross-reactivity to umbelliferone. It is assumed that a skin-protein conjugation at 5 or 6 positions of the coumarin ring is important to elicit the cross-reactivity of esculetin or daphnetin groups.


Asunto(s)
Cumarinas/inmunología , Reacciones Cruzadas , Inmunización , Animales , Cumarinas/química , Cumarinas/metabolismo , Femenino , Cobayas , Técnicas In Vitro , Unión Proteica , Albúmina Sérica/metabolismo , Piel/inmunología , Piel/metabolismo , Relación Estructura-Actividad
12.
Clin Exp Allergy ; 26(5): 563-70, 1996 May.
Artículo en Inglés | MEDLINE | ID: mdl-8735869

RESUMEN

BACKGROUND: The need to develop predictive tests which could identify potential allergens has been recognized for many years. There is as yet no accepted in vitro method for the assessment of contact sensitizers. OBJECTIVE: We have tested the ability of a range of contact allergens to induce in vitro primary sensitization of autologous T cells. METHOD: T-cell proliferation induced by haptens using 2-day cultured human Langerhans cells as antigen-presenting cell was assessed by 3H thymidine incorporation. Antigen specific stimulation was calculated as stimulation indexes. RESULTS: Strong allergens induced in vitro a primary T-cell response in all (trinitrophenyl, TNP: 13/13) or in the majority (fluorescein isothiocyanate, FITC: 7/10) of experiments. An irritant, sodium dodecyl sulfate (SDS), failed to generate a significant T-cell proliferation in any of the experiments (0/10). We obtained a significant lymphoproliferative response to weak sensitizers only in a limited number of experiments: (coumarin: 1/12, citronellal: 0/10, hydroxycitronellal: 2/8). p-Phenylenediamine (PPDA), a prohapten and highly sensitizing chemical in vivo, generated primary sensitization in vitro in only one of six experiments, while Bandrowski's base (BB), a metabolization product of PPDA induced a significant T-cell response in all six experiments. CONCLUSION: The present in vitro model allows discrimination between two groups of substances: strong contact sensitizers (TNP, FITC, BB) on the one hand and weak sensitizers (coumarin, citronellal and hydroxycitronellal) and irritants (SDS) on the other hand. It could be used as a screening in vitro assay to eliminate strong contact allergens before further predictive animal tests have to be performed.


Asunto(s)
Dermatitis por Contacto/inmunología , Haptenos/inmunología , Inmunización , Células de Langerhans/inmunología , Linfocitos T/inmunología , Cumarinas/inmunología , Dermatitis por Contacto/prevención & control , Compuestos de Diazonio/inmunología , Fluoresceína-5-Isotiocianato/efectos adversos , Humanos , Activación de Linfocitos/inmunología , Fenilendiaminas/inmunología , Piridinas/inmunología , Dodecil Sulfato de Sodio/farmacología , Terpenos/inmunología , Trinitrobencenos/inmunología
14.
J Cancer Res Clin Oncol ; 120 Suppl: S28-9, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-8132699

RESUMEN

7-Hydroxycoumarin (7-HC) was chemically conjugated by diazo coupling to carrier proteins such as bovine serum albumin (BSA), thyroglobulin and ovalbumin. These conjugates were characterised by sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS-PAGE) and high-performance liquid chromatography (HPLC). Rabbits were immunised using the 7-HC-BSA conjugate. The highest antibody titre achieved was 1:10,000, as determined by competitive enzyme-linked immunosorbent assay (ELISA). The resulting antibodies were purified by ammonium sulphate precipitation, followed by protein A affinity chromatography. Their purity was assessed by SDS-PAGE and HPLC. These antibodies have been used in the development of a competitive ELISA, an amperometric biosensor and an electrochemical immunoassay. Both the ELISA and amperometric biosensor have been successfully applied to the analysis of 7-HC and its glucuronide conjugate in human urine samples. Each of these antibody-based methods provides a novel approach to the analysis of the main metabolites of coumarin.


Asunto(s)
Anticuerpos , Cumarinas/orina , Animales , Anticuerpos/inmunología , Anticuerpos/aislamiento & purificación , Especificidad de Anticuerpos , Reacciones Antígeno-Anticuerpo , Unión Competitiva , Cromatografía Líquida de Alta Presión , Cumarinas/inmunología , Cumarinas/metabolismo , Electroquímica , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Humanos , Masculino , Ovalbúmina/metabolismo , Conejos , Albúmina Sérica Bovina/metabolismo , Tiroglobulina/metabolismo , Umbeliferonas/inmunología , Umbeliferonas/orina
15.
Biochemistry ; 31(8): 2368-75, 1992 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-1540593

RESUMEN

The fate of the amino termini of nascent polyalanine, polyserine, and polylysine was monitored by fluorescence techniques as each was translated on Escherichia coli ribosomes. A coumarin probe was placed at the alpha-amino group of a synthetic elongator alanyl-tRNA or a synthetic initiator alanyl-tRNA or at the epsilon-amino group of natural lysyl-tRNA, and each was used to nonenzymatically initiate peptide synthesis. The fluorescent alanyl-tRNAs containing an AAA anticodon were used to initiate polyserine (with a synthetic tRNA(Ser] or polyalanine synthesis from a poly(uridylic acid) template. The fluorescent lysyl-tRNA was used to initiate polylysine synthesis from poly(adenylic acid). Changes in the fluorescence of the amino-terminal coumarin were examined to characterize the environment of the probe as the nascent peptides were extended. Protection from proteolysis and the binding of anti-coumarin antibodies or Fab fragments suggest that the amino terminus of each polypeptide is protected from interaction with proteins (Mr greater than 28,000) until the peptides are extended to an average length of 40-50 residues; however, the fluorescence from the amino terminus of shorter nascent polyalanine and polyserine peptides was readily quenched by methyl viologen (Mr = 257), indicating ribosomes do not shield the nascent peptide from molecules of this size. The data appear to indicate that polyalanine, polyserine, and polylysine are extended from the peptidyl transferase into a protected region of the ribosome such as a groove or tunnel but that this region is readily accessible to small molecules.


Asunto(s)
Escherichia coli/química , Péptidos/química , Biosíntesis de Proteínas , Ribosomas/química , Secuencia de Aminoácidos , Animales , Formación de Anticuerpos , Cumarinas/inmunología , Endopeptidasa K , Escherichia coli/genética , Femenino , Polarización de Fluorescencia , Colorantes Fluorescentes , Paraquat/química , Biosíntesis de Péptidos , Péptidos/genética , ARN de Transferencia de Alanina/química , Conejos , Ribosomas/metabolismo , Serina Endopeptidasas/farmacología
17.
Contact Dermatitis ; 15(5): 289-94, 1986 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-3816192

RESUMEN

5 coumarins used in perfumery, cosmetics, therapeutic ointments or occurring naturally were investigated by Freund's complete adjuvant technique (FCAT) in guinea pigs to determine their contact sensitizing potency. 4-Methylesculetin was also studied. Esculetin, dihydrocoumarin and daphnetin were found to be moderate to strong sensitizers, while fraxetin was nearly and 7-methylcoumarin completely inactive. The results corroborate the hypothetical view that only those coumarins having a catecholic disubstitution in the benzene ring, e.g., esculetin, 4-methylesculetin, daphnetin, can become sensitizers on the basis that they are capable of forming ortho-quinones under oxidizing conditions.


Asunto(s)
Cumarinas/inmunología , Dermatitis por Contacto/etiología , Animales , Cosméticos/inmunología , Reacciones Cruzadas , Dermatitis por Contacto/inmunología , Femenino , Adyuvante de Freund/inmunología , Cobayas , Inmunización/métodos , Pruebas Cutáneas , Relación Estructura-Actividad , Umbeliferonas/inmunología
19.
Arch Dermatol ; 117(5): 258-63, 1981 May.
Artículo en Inglés | MEDLINE | ID: mdl-7224654

RESUMEN

Coumarin and several of its derivatives were investigated for their photosensitizing properties. With a few exceptions, the coumarins are potentially strong photocontact sensitizers but do not evoke phototoxic reactions. Substitution at the 6 or 7 positions of the benzopyrone ring confers photoallergenic capability, whereas hydrogenation abolishes activity. Photo-cross-reactions among closely related derivatives can develop. The action spectrum for contact photodermatitis extends from 360 nm down to at least 300 nm. Data are presented to show that the photocontact allergic response is related to the ultraviolet A dose and to the concentration of the offending chemical.


Asunto(s)
Cumarinas/farmacología , Adulto , Cumarinas/administración & dosificación , Cumarinas/inmunología , Reacciones Cruzadas , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Trastornos por Fotosensibilidad/inducido químicamente , Relación Estructura-Actividad
20.
Contact Dermatitis ; 6(2): 131-3, 1980 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7398265

RESUMEN

Further confirmation of the effects of vehicles and elicitation concentration in experimental contact sensitization testing with fragrance ingredients is reported. A dose-response relation was seen when sensitized human subjects were challenged with dihydrocoumarin, alantroot oil and diethylmalleate. Furthermore, alcohol was shown to be a more effective vehicle than petrolatum, when cinnamon bark oil, vetiver acetate and diethylmalleate were used in predictive tests. The relation of these findings to risk-benefit judgments is discussed briefly.


Asunto(s)
Dermatitis por Contacto/inmunología , Inmunización , Irritantes , Vehículos Farmacéuticos/inmunología , Cumarinas/inmunología , Etanol/inmunología , Humanos , Maleatos/inmunología , Aceites/efectos adversos , Vaselina/efectos adversos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA