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1.
SN Bus Econ ; 2(8): 113, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36034544

RESUMEN

The present study analyzes the asymmetric association of exchange rate and world income with inbound tourism demand in India using a recently developed nonlinear autoregressive distributed lag model. For this purpose, the study uses monthly data from January 2003 to December 2020 for inbound tourism demand, real effective exchange rate, and world income as the variables of the model. The study used an asymmetric causality test on the lines of Hatemi-J. The findings confirm the existence of a nonlinear association between exchange rate and tourism demand in the long run. Furthermore, the increases in the world income have a positive and significant effect on tourist arrivals in India. In addition, the findings indicate that exchange rate shocks play a vital role in the long run. The cointegration test is supplemented with nonlinear causality analysis. The causal result depicted positive shocks in the exchange rate and world income sharing a unidirectional causal relationship with tourist arrivals. The result of this research can significantly facilitate the policymakers for devising short-run as well as long-run policies to consolidate the macroeconomic fundamentals such that tourism demand can be enhanced in India.

4.
J Hum Nutr Diet ; 31(4): 513-522, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29468754

RESUMEN

BACKGROUND: Micronutrient deficiency is a global health burden, especially among developing countries. The present cross-sectional study aimed to determine the prevalence of vitamin B12 deficiency in healthy Indian school-going adolescents, based on area of residence, sex and body mass index (BMI). Furthermore, the relationship of serum B12 concentration with dietary vitamin B12 intake and anthropometric indices was assessed among adolescents from rural and urban India. METHODS: A total of 2403 school-going adolescents (11-17 years) from National Capital Region and rural areas of Haryana, India were selected. Serum B12 concentrations were estimated using an electrochemiluminescence immunoassay. Dietary assessments were conducted on 65% of total participants (n = 1556) by two 24-h diet recalls. RESULTS: The prevalence of vitamin B12 deficiency in the total study population was 32.4% (rural: 43.9% versus urban: 30.1%, P < 0.001; male: 34.4% versus female: 31.0%, P < 0.05; normal weight: 28.1%, versus overweight: 39.8%, versus obese: 51.2%, P < 0.001). More than half (51.2%) of obese adolescents were vitamin B12 deficient. On multiple linear regression analysis, serum B12 in rural adolescents was associated with age (ß = -0.12, P < 0.05). Among urban adolescents, serum B12 was associated with BMI (ß = -0.08, P < 0.05) and adjusted dietary vitamin B12 intake (ß = 0.14, P < 0.001). Serum vitamin B12 levels were found to be lower in rural females (ß = -0.12, P = 0.030) and urban males (ß: 0.11, P < 0.001) compared to their respective contemporaries. CONCLUSIONS: Vitamin B12 deficiency was higher among rural school-going adolescents. Boys had a higher B12 deficiency than girls. Inverse associations of serum B12 with adiposity indices were observed. Serum B12 levels were positively associated with dietary vitamin B12 intake.


Asunto(s)
Salud del Adolescente/estadística & datos numéricos , Población Rural , Población Urbana , Deficiencia de Vitamina B 12/epidemiología , Adolescente , Factores de Edad , Índice de Masa Corporal , Niño , Femenino , Humanos , India/epidemiología , Masculino , Obesidad/epidemiología , Sobrepeso/epidemiología , Factores Sexuales , Estudiantes , Vitamina B 12/sangre
5.
Mol Psychiatry ; 23(8): 1745-1755, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-28485408

RESUMEN

Development of an efficacious, non-addicting analgesic has been challenging. Discovery of novel mechanisms underlying addiction may present a solution. Here we target the neurokinin system, which is involved in both pain and addiction. Morphine exerts its rewarding actions, at least in part, by inhibiting GABAergic input onto substance P (SP) neurons in the ventral tegmental area (VTA), subsequently increasing SP release onto dopaminergic neurons. Genome editing of the neurokinin 1 receptor (NK1R) in the VTA renders morphine non-rewarding. Complementing our genetic approach, we demonstrate utility of a bivalent pharmacophore with dual activity as a µ/δ opioid agonist and NK1R antagonist in inhibiting nociception in an animal model of acute pain while lacking any positive reinforcement. These data indicate that dual targeting of the dopaminergic reward circuitry and pain pathways with a multifunctional opioid agonist-NK1R antagonist may be an efficacious strategy in developing future analgesics that lack abuse potential.


Asunto(s)
Antagonistas del Receptor de Neuroquinina-1/farmacología , Trastornos Relacionados con Opioides/prevención & control , Receptores de Neuroquinina-1/metabolismo , Dolor Agudo/tratamiento farmacológico , Dolor Agudo/metabolismo , Analgésicos/farmacología , Animales , Sistemas CRISPR-Cas , Modelos Animales de Enfermedad , Dopamina/metabolismo , Escherichia coli , Técnicas de Silenciamiento del Gen , Masculino , Ratones Endogámicos ICR , Morfina/farmacología , Dolor Nociceptivo/tratamiento farmacológico , Dolor Nociceptivo/metabolismo , Trastornos Relacionados con Opioides/genética , Trastornos Relacionados con Opioides/metabolismo , Ratas Sprague-Dawley , Receptores de Neuroquinina-1/genética , Receptores Opioides delta/agonistas , Receptores Opioides delta/metabolismo , Receptores Opioides mu/agonistas , Receptores Opioides mu/metabolismo , Recompensa , Sustancia P/metabolismo , Área Tegmental Ventral/efectos de los fármacos , Área Tegmental Ventral/metabolismo
6.
Hum Exp Toxicol ; 35(10): 1108-15, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26666987

RESUMEN

ALC67 is an N-acylated thiazolidine compound with promising anticancer activity that led to the recent discovery of a series of 3-propionyl thiazolidine-4-carboxylic acid ethyl esters as a family of novel antiproliferative agents. Since the mutagenic and genotoxic properties of marketed anticancer molecules constitute a main issue to be addressed, this study focused on the analysis of the mutagenicity, antimutagenecity, and genotoxicity of this molecule. The mutagenicity and antimutagenicity of ALC67 were evaluated by Ames test performed on Salmonella TA98 and TA100 strains. The genotoxicity of this molecule was investigated in the chromosomal aberration assay on human lymphocytes. All results revealed that the analyzed structure is not mutagenic in the two Salmonella strains tested and was not genotoxic in human lymphocytes in vitro On the other hand, it showed a weak antimutagenic effect in these two bacterial strains. The above results indicate that after performing some more mutagenicity assays using the other recommended strains, this compound can be safely used for the development of new structures exhibiting anticancer activities.


Asunto(s)
Antineoplásicos/toxicidad , Aberraciones Cromosómicas/inducido químicamente , Linfocitos/efectos de los fármacos , Salmonella/efectos de los fármacos , Tiazolidinas/toxicidad , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Células Cultivadas , Relación Dosis-Respuesta a Droga , Descubrimiento de Drogas , Femenino , Humanos , Concentración 50 Inhibidora , Linfocitos/metabolismo , Masculino , Estructura Molecular , Pruebas de Mutagenicidad , Ratas Sprague-Dawley , Salmonella/genética , Tiazolidinas/síntesis química , Tiazolidinas/química
8.
Acta Mater ; 97: 245-256, 2015 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-27099566

RESUMEN

Currently, there is significant interest in magnetocaloric materials for solid state refrigeration. In this work, polycrystalline Heusler alloys belonging to the Ni2+xMn1-xGa family, with x between 0.08 and 0.24, were evaluated for the purpose of finding composition(s) with an enhanced magnetocaloric effect (MCE) close to room temperature. Differential scanning calorimetry (DSC) was successfully used to screen alloy composition for simultaneous magnetic and structural phase transformations; this coupling needed for a giant MCE. The alloy with x = 0.16 showed an excellent match of transformation temperatures and exhibited the highest magnetic entropy change, ΔSM, in the as-annealed state. Furthermore, the MCE increased by up to 84 % with a 2 Tesla (T) field change when the samples were thermally cycled through the martensite to austenite transformation temperature while held under a constant mechanical load. The highest ΔSM measured for our x = 0.16 alloy for a 2 T magnetic field change was -18 J/kg-K. Texture measurements suggest that preferential orientation of martensite variants contributed to the enhanced MCE in the stress-assisted thermally cycled state.

10.
Environ Sci Pollut Res Int ; 20(3): 1281-91, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23093415

RESUMEN

In this work, removal of arsenic (III) from aqueous solution by living cells (Bacillus cereus), biosorption mechanism, and characterization studies have been reported. B. cereus cell surface was characterized using SEM-EDX and FTIR. Dependence of biosorption on pH of the solution, biosorbent dose, initial arsenic (III) concentration, contact time, and temperature had been studied to achieve optimum condition. The maximum biosorption capacity of living cells of B. cereus for arsenic (III) was found to be 32.42 mg/g at pH 7.5, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data of arsenic (III) are fitted to linearly transformed Langmuir isotherm with R (2) (correlation coefficient) >0.99. The pseudo-second-order model description of the kinetics of arsenic (III) is successfully applied to predict the rate constant of biosorption. Thermodynamic parameters reveal the endothermic, spontaneous, and feasible nature of sorption process of arsenic (III) onto B. cereus biomass. The arsenic (III) ions are desorbed from B. cereus using both 1 M HCl and 1 M HNO(3).


Asunto(s)
Arsénico/metabolismo , Bacillus cereus/metabolismo , Contaminantes Químicos del Agua/metabolismo , Biodegradación Ambiental , Biomasa , Concentración de Iones de Hidrógeno , Cinética , Microscopía Electrónica de Rastreo , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Factores de Tiempo
11.
Water Sci Technol ; 66(8): 1699-707, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22907454

RESUMEN

In this work, the biosorption of As(V) from aqueous solutions by living cells of Bacillus cereus has been reported. The batch biosorption experiments were conducted with respect to biosorbent dosage 0.5 to 15 g/L, pH 2 to 9, contact time 5 to 90 min, initial concentration 1 to 10 mg/L and temperature 10 to 40 °C. The maximum biosorption capacity of B. cereus for As(V) was found to be 30.04 at pH 7.0, at optimum conditions of contact time of 30 min, biomass dosage of 6 g/L, and temperature of 30 ± 2 °C. Biosorption data were fitted to linearly transformed Langmuir isotherms with R(2) (correlation coefficient) >0.99. Bacillus cereus cell surface was characterized using AFM and FTIR. The metal ions were desorbed from B. cereus using both 1 M HCl and 1 M HNO(3). The pseudo-second-order model was successfully applied to predict the rate constant of biosorption.


Asunto(s)
Arsénico/metabolismo , Bacillus cereus/metabolismo , Biodegradación Ambiental , Contaminantes Químicos del Agua/metabolismo , Soluciones
12.
Indian J Cancer ; 49(1): 114-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22842178

RESUMEN

AIM OF THE STUDY: A totally implantable venous access port (TIVAP) has become an essential prerequisite for many chemotherapy protocols. It is serving its purpose very well, but its use is not without complications. We are presenting our experience with these devices (TIVAPs). SUBJECTS AND METHODS: We retrospectively reviewed the totally implantable venous access ports in 81 patients at our hospital between January 2009 and March 2011 for long-term problems which include postoperative and follow-up problems, excluding the immediate complications which occur at the time of insertion. RESULTS: Catheter malfunction was the most common complication (9.87%, 0.40/1000 device-days of use/observation). Catheter-related bloodstream infections were present in 5 (6.17%) patients (0.25/1000 device-days of use/observation). The mean life of the catheter was 246 days. Only 11.1% ports required removal during the treatment period. Overall, patients either completed treatment (82.8%) or died (6.1%) while receiving treatment. CONCLUSION: TIVAPs provide safe and reliable vascular access for patients on chemotherapy but require utmost care by a dedicated team of trained medical professionals and paramedics experienced with the use of such ports, in order to minimize the complications and their continued use while administering treatment.


Asunto(s)
Infecciones Relacionadas con Catéteres , Cateterismo Venoso Central/efectos adversos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Neoplasias/tratamiento farmacológico , Adulto , Anciano , Infecciones Relacionadas con Catéteres/patología , Infecciones Relacionadas con Catéteres/terapia , Catéteres de Permanencia/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad
13.
Water Sci Technol ; 63(5): 899-907, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21411939

RESUMEN

In this work, the phytoremediation of Cr (VI) and Hg (II) ion from water by an aquatic plant Eichhornia crassipes has been studied. Plants were cultured in a double distillated water with modified Hoagland's nutrient solution at pH 6.8 supplemented with 0, 0.75, 1.50, 2.50, and 4 mg Cr/L as potassium dichromate (K(2)Cr(2)O(7)) and 0, 5, 10, 15, and 20 mg Hg/L as mercuric chloride (HgCl(2)). They were separately harvested after 3, 6 and 9 days. Plants treated with 4 mg/L of Cr (VI) accumulated the highest concentration of metal in roots (1.22 mg/g, dry weight) and shoots (0.24 mg/g, dry weight) after 9 days; while those treated with 20 mg/L of Hg (II) accumulated the highest concentration of metal in roots (4.22 mg/g, dry weight) and shoots (2.43 mg/g, dry weight) after 9 days. Eichhornia crassipes biomass was characterised using AAS, SEM and FTIR. The accumulation and relative growth of metal ions at different concentrations of chromium and mercury solution significantly increased (P<0.05) with the passage of time. The maximum values of bio-concentration factor (BCF) for Cr (VI) and Hg (II) were found to be 413.33 and 502.40 L/kg respectively.


Asunto(s)
Cromo/toxicidad , Eichhornia/química , Eichhornia/metabolismo , Mercurio/toxicidad , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Biomasa , Cromo/química , Cromo/metabolismo , Eichhornia/ultraestructura , Mercurio/química , Mercurio/metabolismo , Oxidación-Reducción , Oxígeno , Raíces de Plantas/química , Raíces de Plantas/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Agua/química , Contaminantes Químicos del Agua
14.
Hum Exp Toxicol ; 27(5): 381-6, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18715884

RESUMEN

Over six million people in nine districts of West Bengal, India are exposed to very high levels of arsenic primarily through their drinking water. More than 300,000 people showed arsenic-induced skin lesions in these districts. This is regarded as the greatest arsenic calamity in the world. Chronic arsenicosis causes varied dermatological signs ranging from pigmentation changes, hyperkeratosis to non-melanocytic cancer of skin, and also malignancies in different internal organs. Higher incidences of opportunistic infections are found in the arsenic-exposed individuals, indicating that their immune systems may be impaired somehow. We have thus investigated the effect of arsenic on T-cell proliferation and cytokine secretion in 20 individuals with arsenic-induced skin lesions and compared the results with 18 arsenic-unexposed individuals. A marked dose-dependent suppression of Concanavalin A (Con A) induced T-cell proliferation was observed in the arsenic-exposed individuals compared with the unexposed (P < 0.001) individuals. This correlated with a significant decrease in the levels of secreted cytokines by the T cells (TNF-alpha, IFN-gamma, IL2, IL10, IL5, and IL4) in the exposed individuals (P < 0.001). Thus it can be inferred that arsenic exposure can cause immunosuppression in humans.


Asunto(s)
Intoxicación por Arsénico/inmunología , Citocinas/metabolismo , Exposición a Riesgos Ambientales , Linfocitos T/inmunología , Contaminantes Químicos del Agua/toxicidad , Adulto , Células Cultivadas , Concanavalina A/farmacología , Estudios Transversales , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Activación de Linfocitos/efectos de los fármacos , Masculino , Persona de Mediana Edad , Enfermedades de la Piel/sangre , Enfermedades de la Piel/inducido químicamente , Enfermedades de la Piel/patología , Abastecimiento de Agua/análisis
15.
Toxicol Appl Pharmacol ; 230(1): 57-66, 2008 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-18377941

RESUMEN

Arsenic contamination in drinking water is one of the biggest natural calamities, which has become an imperative threat to human health throughout the world. Abbreviation of erythrocyte lifespan leading to the development of anemia is a common sequel in arsenic exposed population. This study was undertaken to explore the mechanism of cell death in human erythrocytes during chronic arsenic exposure. Results revealed transformation of smooth discoid red cells into evaginated echinocytic form in the exposed individuals. Further distortion converted reversible echinocytes to irreversible spheroechinocytes. Arsenic toxicity increased membrane microviscosity along with an elevation of cholesterol/phospholipid ratio, which hampered the flexibility of red cell membrane and made them less deformable. Significant increase in the binding of merocyanine 540 with erythrocyte membrane due to arsenic exposure indicated disruption of lipid packing in the outer leaflet of the cell membrane resulting from altered transbilayer phospholipid asymmetry. Arsenic induced eryptosis was characterized by cell shrinkage and exposure of phosphatidylserine at the cell surface. Furthermore, metabolic starvation with depletion of cellular ATP triggered apoptotic removal of erythrocytes from circulation. Significant decrease in reduced glutathione content indicating defective antioxidant capacity was coupled with enhancement of malondialdehyde and protein carbonyl levels, which pointed to oxidative damage to erythrocyte membrane. Arsenic toxicity intervened into red cell membrane integrity eventually leading to membrane destabilization and hemoglobin release. The study depicted the involvement of both erythrophagocytosis and hemolysis in the destruction of human erythrocytes during chronic arsenic exposure.


Asunto(s)
Anexina A5/efectos de los fármacos , Arsénico/efectos adversos , Membrana Eritrocítica/efectos de los fármacos , Hemólisis/efectos de los fármacos , Fosfatidilserinas/metabolismo , Contaminantes Químicos del Agua/efectos adversos , Adulto , Anemia/etiología , Anexina A5/metabolismo , Arsénico/análisis , Arsénico/orina , Membrana Eritrocítica/metabolismo , Femenino , Humanos , India , Masculino , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/orina
16.
Cytogenet Genome Res ; 104(1-4): 359-64, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15162065

RESUMEN

For centuries arsenic has played an important role in science, technology, and medicine. Arsenic for its environmental pervasiveness has gained unexpected entrance to the human body through food, water and air, thereby posing a great threat to public health due to its toxic effect and carcinogenicity. Thus, in modern scenario arsenic is synonymous with "toxic" and is documented as a paradoxical human carcinogen, although its mechanism of induction of neoplasia remains elusive. To assess the risk from environmental and occupational exposure of arsenic, in vivo cytogenetic assays have been conducted in arseniasis-endemic areas of the world using chromosomal aberrations (CA) and sister chromatid exchanges (SCE) as biomarkers in peripheral blood lymphocytes. The primary aim of this report is to critically review and update the existing in vivo cytogenetic studies performed on arsenic-exposed populations around the world and compare the results on CA and SCE from our own study, conducted in arsenic-endemic villages of North 24 Parganas (district) of West Bengal, India from 1999 to 2003. Based on a structured questionnaire, 165 symptomatic (having arsenic induced skin lesions) subjects were selected as the exposed cases consuming water having a mean arsenic content of 214.96 microg/l. For comparison 155 age-sex matched control subjects from an unaffected district (Midnapur) of West Bengal were recruited. Similar to other arsenic exposed populations our population also showed a significant difference (P < 0.01) in the frequencies of CA and SCE between the cases and control group. Presence of substantial chromosome damage in lymphocytes in the exposed population predicts an increased future carcinogenic risk by this metalloid.


Asunto(s)
Arsénico/efectos adversos , Aberraciones Cromosómicas , Cromosomas Humanos/genética , Adulto , Contaminantes Ocupacionales del Aire/efectos adversos , Arsénico/análisis , Niño , Rotura Cromosómica , Cromosomas Humanos/ultraestructura , Exposición a Riesgos Ambientales , Diseño de Investigaciones Epidemiológicas , Femenino , Salud Global , Humanos , India/epidemiología , Linfocitos/efectos de los fármacos , Linfocitos/ultraestructura , Masculino , Concentración Máxima Admisible , Pruebas de Micronúcleos , Persona de Mediana Edad , Pruebas de Mutagenicidad , Mutágenos/efectos adversos , Exposición Profesional , Intercambio de Cromátides Hermanas/efectos de los fármacos , Enfermedades de la Piel/inducido químicamente , Enfermedades de la Piel/epidemiología , Contaminantes Químicos del Agua/efectos adversos , Abastecimiento de Agua
17.
Mutat Res ; 534(1-2): 133-43, 2003 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-12504762

RESUMEN

Arsenic contamination in groundwater has become a worldwide problem. Currently an unprecedented number of people in West Bengal, India and Bangladesh are exposed to the ubiquitous toxicant via drinking water in exposure levels far exceeding the maximum recommended limit laid down by WHO. This arsenic epidemic has devastated nine districts of West Bengal encompassing an area of 38,865 km(2) leading to various clinical manifestations of chronic arsenicosis. We conducted a human bio-monitoring study using chromosomal aberrations (CA) and sister chromatid exchanges (SCE) as end points to explore the cytogenetic effects of chronic arsenic toxicity in the population of North 24 Parganas, one of the arsenic affected districts in West Bengal. Study participants included 59 individuals residing in this district where the mean level (+/-S.E.) of arsenic in drinking water (microg/l) was 211.70+/-15.28. As age matched controls with similar socio-economic status we selected 36 healthy, asymptomatic individuals residing in two unaffected districts--Midnapur and Howrah where the mean arsenic content of water (microg/l) was 6.35+/-0.45. Exposure was assessed by standardized questionnaires and by detecting the levels of arsenic in drinking water, nails, hair and urine samples. In the exposed group the mean arsenic concentrations in nails (microg/g), hair (microg/g) and urine (microg/l) samples were 9.04+/-0.78, 5.63+/-0.38 and 140.52+/-8.82, respectively, which were significantly high (P<0.01) compared to the corresponding control values of 0.44+/-0.03, 0.30+/-0.02 and 5.91+/-0.49, respectively. Elevated mean values (P<0.01) of the percentage of aberrant cells (8.08%) and SCEs per cell (7.26) were also observed in the exposed individuals in comparison to controls (1.96% and 5.95, respectively). The enhanced rates of CAs and SCEs among the residents of North 24 Parganas are indicative of the cytogenetic damage due to long term exposure to arsenic through consumption of contaminated water.


Asunto(s)
Arsénico/toxicidad , Aberraciones Cromosómicas , Intercambio de Cromátides Hermanas , Contaminantes Químicos del Agua/toxicidad , Adolescente , Adulto , Anciano , Arsénico/análisis , Arsénico/orina , Intoxicación por Arsénico/epidemiología , Intoxicación por Arsénico/patología , Estudios de Casos y Controles , Femenino , Agua Dulce , Cabello/química , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Uñas/química , Piel/patología
18.
Phytother Res ; 16(7): 655-61, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12410547

RESUMEN

Almost two thirds of the world population consume tea everyday. Tea is processed differently in different parts of the world to give green (20%), black (78%) or oolong tea (2%). The antimutagenic and anticarcinogenic activities of green tea were extensively investigated compared with those of black tea. Considering the potent antimutagenic effects of green tea we recognized the need to evaluate the antimutagenic effects of black tea (World Blend Tea, Southern Tea Co., Marietta, GA) in Salmonella strains TA97a, TA98, TA100 and TA102 in preincubation tests, both with and without S9 activation. Attempts have also been made to compare the results of the tea extracts with their two active polyphenols theaflavins and thearubigins. Antimutagenicity assays were carried out in bacterial plates treated with different concentrations (1%, 2.5%, 5%, 10% and 20%) of tea extracts against known bacterial mutagens sodium azide, 4-nitro-o-phenylenediamine, cumine hydroperoxide, 2-aminofluorene and danthron. A significant decrease in the number of revertant colonies was observed in the plates treated with 1% to 20% of tea extract plus positive mutagen when compared with positive mutagen only. Both the active polyphenols theaflavins and thearubigins extracted from the black tea (World blend) also showed significant antimutagenic effects against known positive compounds in these strains. In the experiments with S9 activation, the antimutagenic effects were significantly higher. These results indicate that black tea and its two polyphenols have significant antimutagenic effects in Ames Salmonella assays.


Asunto(s)
Antimutagênicos/farmacología , Biflavonoides , Catequina/análogos & derivados , Flavonoides , Fenoles/farmacología , Fitoterapia , Extractos Vegetales/farmacología , Polímeros/farmacología , Salmonella/efectos de los fármacos , , Animales , Antimutagênicos/administración & dosificación , Antimutagênicos/uso terapéutico , Catequina/administración & dosificación , Catequina/farmacología , Catequina/uso terapéutico , Relación Dosis-Respuesta a Droga , Masculino , Pruebas de Mutagenicidad , Fenoles/administración & dosificación , Fenoles/uso terapéutico , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Polímeros/administración & dosificación , Polímeros/uso terapéutico , Polifenoles , Ratas , Salmonella/genética
19.
Mutat Res ; 512(1): 37-65, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12220589

RESUMEN

Tea is the most popular beverage next to water, consumed by over two-thirds of the world's population. It is processed in different ways in different parts of the world to give green, black or oolong tea. Experimental studies have demonstrated the significant antimutagenic and anticlastogenic effects of both green and black tea and its polyphenols in multiple mutational assays. In the present review, we have attempted to evaluate and update the comparative antimutagenic and anticlastogenic effects of green tea, black tea and their polyphenols in different test systems, based on available literature. Existing reports have suggested that the protective effects of black tea is as good as green tea, however, more studies on black tea and its polyphenols are needed before a final conclusion can be made.


Asunto(s)
Anticarcinógenos/farmacología , Antimutagênicos/farmacología , Biflavonoides , Flavonoides , , Animales , Catequina/farmacología , Células Cultivadas/efectos de los fármacos , Cricetinae , Cricetulus , Aductos de ADN , Escherichia coli/efectos de los fármacos , Fermentación , Genes Bacterianos/efectos de los fármacos , Genes Dominantes/efectos de los fármacos , Genes Letales/efectos de los fármacos , Humanos , Ratones , Pruebas de Mutagenicidad , Mutágenos/farmacología , Fenoles/farmacología , Polímeros/farmacología , Ratas , Salmonella typhimurium/efectos de los fármacos , Té/clasificación
20.
Mutat Res ; 516(1-2): 29-40, 2002 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-11943608

RESUMEN

In West Bengal, India arsenic in ground water has been found to be above the maximum permissible limit in seven districts covering an area of 37,493km2. In the present study, evaluation of the micronuclei (MN) formation in oral mucosa cells, urothelial cells and peripheral blood lymphocytes was carried out in the symptomatic individuals exposed to arsenic through drinking water. Forty five individuals with cutaneous signs of arsenicism from four affected districts (368.11 microg/l of As in drinking water) were considered as the exposed group and 21 healthy individuals with no symptoms of arsenic poisoning and residing in two unaffected districts (5.49 microg/l of As) were considered as controls. The exposed and control groups had similar age distribution and socioeconomic status. Standardised questionnaires were utilised and medical examination was conducted to ascertain exposure history, sociodemographic characteristics, diet, health, medication, addiction and chief symptoms in the study participants. Arsenic exposure was confirmed by measuring the arsenic content in the drinking water, nails, hair and urine samples from the volunteers. Arsenic contents in the urine, nail and hair in the exposed group were 24.45 microg/l, 12.58 and 6.97 microg/g, respectively which were significantly high in comparison to corresponding control group values of 4.88 microg/l, 0.51 and 0.34 microg/g, respectively. Exposed individuals showed a statistically significant increase in the frequency of MN in oral mucosa, urothelial cells and lymphocytes (5.15, 5.74 and 6.39/1000 cells, respectively) when compared with the controls (0.77, 0.56 and 0.53/1000 cells, respectively). Thus, the above results indicate that the symptomatic individuals exposed to arsenic through drinking water in this region have significant cytogenetic damage.


Asunto(s)
Arsénico/efectos adversos , Exposición a Riesgos Ambientales/efectos adversos , Células Epiteliales/patología , Micronúcleos con Defecto Cromosómico/patología , Contaminantes Químicos del Agua/efectos adversos , Adolescente , Adulto , Arsénico/metabolismo , Arsénico/orina , Núcleo Celular/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Femenino , Humanos , India/epidemiología , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Masculino , Pruebas de Micronúcleos , Persona de Mediana Edad , Mucosa Bucal/efectos de los fármacos , Mucosa Bucal/metabolismo , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/metabolismo , Contaminantes Químicos del Agua/análisis
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