RESUMEN
Declining rate of human fertility is a growing concern, where lifestyle and environmental factors play an important role. We recently demonstrated that tributyltin (TBT), an omnipresent endocrine disruptor, affects testicular cells in vitro. In this study, male Wistar rats were gavaged a single dose of 10, 20, and 30 mg/kg TBT-chloride (TBTC) (to mimic accidental exposure in vivo) and sacrificed on day 3 and day 7, respectively. TBT bioavailability was evaluated by estimating total tin content, and essential metal levels were analyzed along with redox molecules (ROS and GSH/GSSG) to understand the effect on physiological conditions. Blood-testicular barrier (BTB) disruption, levels of associated proteins and activity of proteolytic enzymes were evaluated to understand the effect on BTB. Histological analysis of tissue architecture and effect on protein expression of steroidogenic, stress and apoptotic markers were also evaluated. Widespread TBTC pollution can be an eventual threat to male fertility worldwide.
Asunto(s)
Disruptores Endocrinos/toxicidad , Fertilidad/efectos de los fármacos , Compuestos de Trialquiltina/toxicidad , Animales , Apoptosis , Peso Corporal/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Masculino , Tamaño de los Órganos/efectos de los fármacos , Oxidación-Reducción , Estrés Oxidativo/efectos de los fármacos , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Testículo/efectos de los fármacos , Testículo/metabolismoRESUMEN
CONTEXT: Cadmium (Cd) is known to cause severe damage to various organs including lung, liver, kidney, brain and reproductive system. Several studies have reported the induction of oxidative stress pathways following Cd exposure. OBJECTIVE: Since oxidative stress is also deemed responsible for inducing male infertility, a growing worldwide concern, we tried to understand whether the antioxidant N-acetylcysteine (NAC) can be a potential therapeutic agent to counter Cd toxicity using primary Leydig cells. MATERIALS AND METHODS: This study highlights the initial cellular alterations which culminate in cell death induction. Primary Leydig cells were isolated from 28-day-old male Wistar rats, exposed to various concentrations of Cd in vitro and biochemical and cell death parameters were evaluated to understand the effect of Cd. NAC pre-treatment was done to understand its protective efficacy. RESULTS: Following Cd exposure to Leydig cells in vitro, we found simultaneous intracellular calcium (Ca(2+)) increase and reduction in mitochondrial membrane polarization at 30 min, followed by significant induction of reactive oxygen species and MAPK-extracellular-regulated kinases with concurrent glutathione depletion at 1 h, and significant cell death (both necrotic and apoptotic) at 6 and 18 h, respectively. Pre-treatment with NAC abrogated all these toxic manifestations and showed significantly reduced cell death. NAC also rescued the expression of 3-ßHSD, a major steroidogenic protein. DISCUSSION AND CONCLUSION: Taken together, these data illustrated that NAC can be used as a potential protective agent against Cd-induced testicular toxicity, especially with regards to oxidative stress-induced Leydig cell toxicity.
Asunto(s)
Acetilcisteína/farmacología , Antioxidantes/farmacología , Cadmio/toxicidad , Estrés Oxidativo/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Cadmio/administración & dosificación , Calcio/metabolismo , Muerte Celular/efectos de los fármacos , Glutatión/metabolismo , Células Intersticiales del Testículo/efectos de los fármacos , Masculino , Membranas Mitocondriales/efectos de los fármacos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Factores de TiempoRESUMEN
Spirulina is a widely used health supplement and is a dietary source of C-Phycocyanin (CPC), a potent anti-oxidant. We have previously reported the neurotoxic potential of tributyltin chloride (TBTC), an environmental pollutant and potent biocide. In this study, we have evaluated the protective efficacy of CPC against TBTC induced neurotoxicity. To evaluate the extent of neuroprotection offered by CPC, its efficacy was compared with the degree of protection offered by N-acetylcysteine (NAC) (a well known neuroprotective drug, taken as a positive control). Male Wistar rats (28 day old) were administered with 20mg/kg TBTC (oral) and 50mg/kg CPC or 50mg/kg NAC (i.p.), alone or in combination, and various parameters were evaluated. These include blood-brain barrier (BBB) damage; redox parameters (ROS, GSH, redox pathway associated enzymes, oxidative stress markers); inflammatory, cellular, and stress markers; apoptotic proteins and in situ cell death assay (TUNEL). We observed increased CPC availability in cortical tissue following its administration. Although BBB associated proteins like claudin-5, p-glycoprotein and ZO-1 were restored, CPC/NAC failed to protect against TBTC induced overall BBB permeability (Evans blue extravasation). Both CPC and NAC remarkably reduced oxidative stress and inflammation. NAC effectively modulated redox pathway associated enzymes whereas CPC countered ROS levels efficiently. Interestingly, CPC and NAC were equivalently capable of reducing apoptotic markers, astroglial activation and cell death. This study illustrates the various pathways involved in CPC mediated neuroprotection against this environmental neurotoxicant and highlights its capability to modulate glial cell activity.
Asunto(s)
Acetilcisteína/farmacología , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Fármacos Neuroprotectores/farmacología , Ficocianina/farmacología , Animales , Apoptosis/efectos de los fármacos , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Glutatión/metabolismo , Masculino , Estrés Oxidativo/efectos de los fármacos , Oxidorreductasas/metabolismo , Permeabilidad/efectos de los fármacos , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Compuestos de Trialquiltina/toxicidadRESUMEN
Tributyltin (TBT), a well-known endocrine disruptor, is an omnipresent environmental pollutant and is explicitly used in many industrial applications. Previously we have shown its neurotoxic potential on cerebral cortex of male Wistar rats. As the effect of TBT on other brain regions is not known, we planned this study to evaluate its effect on four brain regions (cerebellum, hippocampus, hypothalamus, and striatum). Four-week-old male Wistar rats were gavaged with a single dose of TBT-chloride (TBTC) (10, 20, and 30 mg/kg) and sacrificed on days 3 and 7, respectively. Effect of TBTC on blood-brain barrier (BBB) permeability and tin (Sn) accumulation were measured. Oxidative stress indexes such as reactive oxygen species (ROS), reduced and oxidized glutathione (GSH/GSSG) ratio, lipid peroxidation, and protein carbonylation were analyzed as they play an imperative role in various neuropathological conditions. Since metal catalyzed reactions are a major source of oxidant generation, levels of essential metals like iron (Fe), zinc (Zn), and calcium (Ca) were estimated. We found that TBTC disrupted BBB and increased Sn accumulation, both of which appear significantly correlated. Altered metal homeostasis and ROS generation accompanied by elevated lipid peroxidation and protein carbonylation indicated oxidative damage which appeared more pronounced in the striatum than in cerebellum, hippocampus, and hypothalamus. This could be associated to the depleted GSH levels in striatum. These results suggest that striatum is more susceptible to TBTC induced oxidative damage as compared with other brain regions under study.
Asunto(s)
Encéfalo/efectos de los fármacos , Compuestos de Trialquiltina/toxicidad , Animales , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Calcio/análisis , Corteza Cerebral/efectos de los fármacos , Cuerpo Estriado/metabolismo , Glutatión/metabolismo , Hierro/análisis , Peroxidación de Lípido/efectos de los fármacos , Masculino , Estrés Oxidativo/efectos de los fármacos , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Espectrofotometría Atómica , Zinc/análisisRESUMEN
Tributyltin (TBT) is a potent biocide and commonly used in various industrial sectors. Humans are mainly exposed through the food chain. We have previously demonstrated tin accumulation in brain following TBT-chloride (TBTC) exposure. In this study, effect of TBTC on dissociated cells from different brain regions was evaluated. Cytotoxicity assay (MTT), mode of cell death (Annexin V/PI assay), oxidative stress parameters (ROS and lipid peroxidation), reducing power of the cell (GSH), mitochondrial membrane potential (MMP) and intracellular Ca(2+) were evaluated to ascertain the effect of TBTC. Expression of glial fibrillary acidic protein (GFAP) was measured to understand the effect on astroglial cells. TBTC as low as 30 nM was found to reduce GSH levels, whereas higher doses of 300 and 3000 nM induced ROS generation and marked loss in cell viability mainly through apoptosis. Striatum showed higher susceptibility than other regions, which may have further implications on various neurological aspects.
Asunto(s)
Encéfalo/citología , Encéfalo/efectos de los fármacos , Desinfectantes/toxicidad , Compuestos de Trialquiltina/toxicidad , Animales , Encéfalo/metabolismo , Calcio/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Proteína Ácida Fibrilar de la Glía/metabolismo , Glutatión/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Tributyltin (TBT), a member of the organotin family, is a known endocrine disruptor. It persists long in the environment and is widely used in various industrial applications. This study was planned to understand its toxic influence on Leydig cells isolated from 28 day old wistar rats. In-vitro exposure to TBT-Chloride (TBTC) (300-3000 nM) reduced cell viability (DNA fragmentation, nuclear condensation and MTT assay) and affected testosterone production. TBTC induced both apoptotic and necrotic cell death (AnnexinV/PI binding assay). Involvement of calcium (Ca(2+)), redox imbalance (ROS, GSH and TBARS) and mitochondria in TBTC toxicity was evaluated by using Ca(2+) inhibitors (BAPTA-AM, EGTA, Ruthenium Red), free radical scavengers (NAC, C-Phycocyanin) and mitochondrial permeability transition pore inhibitor (Cyclosporine A). Protein expression analysis of phosphorylated MAPKinases (ERK1/2, JNK1/2, & p38), steroidogenic proteins (3ß-HSD, StAR & TSPO) and apoptotic proteins (Bax, Bcl2) illustrates the cytotoxic and anti-steroidogenic activity of TBTC.
Asunto(s)
Disruptores Endocrinos/toxicidad , Contaminantes Ambientales/toxicidad , Células Intersticiales del Testículo/efectos de los fármacos , Compuestos de Trialquiltina/toxicidad , 3-Hidroxiesteroide Deshidrogenasas/metabolismo , Animales , Apoptosis/efectos de los fármacos , Calcio/metabolismo , Proteínas Portadoras/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Glutatión/metabolismo , Células Intersticiales del Testículo/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , Fosfoproteínas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Receptores de GABA-A/metabolismo , Testosterona/metabolismo , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Tributyltin (TBT) pollution is rampant worldwide and is a growing threat due to its bio-accumulative property. Isolated studies of TBT toxicity on different organs are available but consolidated information is greatly lacking. We planned this study to delineate the effect of subchronic (1 month) exposure to low dose TBT-chloride (TBTC) (1 and 5 mg/kg) in male Wistar rats. Total tin concentration was found to be significantly increased in liver, kidney and blood, and marginally in lungs. Organo-somatic indices were seen to be altered with little effect on serum biochemical markers (liver and kidney function, and general parameters). Reactive oxygen species but not lipid peroxidation content was observed to be significantly elevated both in the tissues and serum. TBTC was found to act as a hyperlipidemic agent and it also affected heme biosynthetic pathway. Hematological analysis showed that TBTC exposure resulted in minor alterations in RBC parameters. Histological studies demonstrated marked tissue damage in all the 3 organs. Calcium inhibitors (BAPTA-AM, EGTA) and antioxidants (NAC, C-PC) significantly restored TBTC induced loss in cell viability, under ex-vivo conditions. Antioxidants were evidently more efficient in comparison to the calcium inhibitors, implying major role of oxidative stress pathways in TBTC toxicity.
Asunto(s)
Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Compuestos de Trialquiltina/toxicidad , Animales , Peso Corporal/efectos de los fármacos , Riñón/metabolismo , Hígado/metabolismo , Masculino , Tamaño de los Órganos/efectos de los fármacos , Estrés Oxidativo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismoRESUMEN
The widespread use of tributyltin (TBT) as biocides in antifouling paints and agricultural chemicals has led to environmental and marine pollution. Human exposure occurs mainly through TBT contaminated seafood and drinking water. It is a well known endocrine disruptor in mammals, but its molecular mechanism in testicular damage is largely unexplored. This study was therefore, designed to ascertain effects of tributyltin chloride (TBTC) on sertoli-germ cell co-culture in ex-vivo and in the testicular tissue in-vivo conditions. An initial Ca(2+) rise followed by ROS generation and glutathione depletion resulted in oxidative damage and cell death. We observed p38 and JNK phosphorylation, stress proteins (Nrf2, MT and GST) induction and mitochondrial depolarization leading to caspase-3 activation. Prevention of TBTC reduced cell survival and cell death by Ca(2+) inhibitors and free radical scavengers specify definitive role of Ca(2+) and ROS. Sertoli cells were found to be more severely affected which in turn can hamper germ cells functionality. TBTC exposure in-vivo resulted in increased tin content in the testis with enhanced Evans blue leakage into the testicular tissue indicating blood-testis barrier disruption. Tesmin levels were significantly diminished and histopathological studies revealed marked tissue damage. Our data collectively indicates the toxic manifestations of TBTC on the male reproductive system and the mechanisms involved.
Asunto(s)
Muerte Celular/efectos de los fármacos , Células Germinativas/efectos de los fármacos , MAP Quinasa Quinasa 4/metabolismo , Células de Sertoli/efectos de los fármacos , Enfermedades Testiculares/inducido químicamente , Compuestos de Trialquiltina/toxicidad , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Apoptosis/efectos de los fármacos , Barrera Hematotesticular/efectos de los fármacos , Calcio/metabolismo , Bloqueadores de los Canales de Calcio/farmacología , Técnicas de Cocultivo , Colorantes , Fragmentación del ADN/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Depuradores de Radicales Libres/farmacología , Glutatión/metabolismo , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Metalotioneína/metabolismo , Necrosis , Oxidación-Reducción , Fosforilación , Ratas , Especies Reactivas de Oxígeno/metabolismo , Enfermedades Testiculares/patología , Testículo/efectos de los fármacos , Testículo/metabolismo , Testículo/patologíaRESUMEN
Tributyltin (TBT), a member of the organotin family, is primarily used for its biocidal activity. Persistent environmental levels of TBT pose threat to the ecosystem. Since neurotoxic influence of TBT remains elusive, we therefore, studied its effect on cerebral cortex of male Wistar rats. A single oral dose of Tributyltin-Chloride (TBTC) (10, 20, 30mg/kg) was administered and the animals were sacrificed on day 3 and day 7. Blood-brain barrier permeability remained disrupted significantly till day 7 with all the doses of TBTC. Pro-oxidant metal levels (Fe, Cu) were increased with a concomitant decrease in Zn. ROS generation was substantially raised resulting in oxidative damage (increased protein carbonylation and lipid peroxidation) with marked decline in tissue antioxidant status (GSH/GSSG levels). Protein expression studies indicated astrocyte activation, upregulation of inflammatory molecules (IL-6, Cox-2 and NF-κB) and simultaneous elevation in the apoptotic index (Bax/Bcl2). Neurodegeneration was evident by reduced neurofilament expression and increased calpain cleaved Tau levels. The in-vitro study demonstrated involvement of calcium and signaling molecules (p38), with downstream activation of caspase-3 and -8, and apoptotic cell death was evident by nuclear fragmentation, DNA laddering and Annexin V binding experiments. Ca(2+) inhibitors (BAPTA-AM, EGTA, and RR) and free radical scavengers (NAC and biliprotein [C-PC]) increased cell viability (MTT assay), signifying specific roles of Ca(2+) and ROS. Significance of p38 signaling was evaluated on pro-apoptotic proteins by using SB203580, a selective p38 inhibitor. Our data collectively illustrates that TBTC can disrupt BBB, induce oxidative stress, cause cell death and initiate neurodegeneration in rat brain.
Asunto(s)
Apoptosis/efectos de los fármacos , Barrera Hematoencefálica/efectos de los fármacos , Corteza Cerebral/efectos de los fármacos , Contaminantes Ambientales/toxicidad , Metales Pesados/metabolismo , Estrés Oxidativo/efectos de los fármacos , Compuestos de Trialquiltina/toxicidad , Animales , Antioxidantes/metabolismo , Astrocitos/efectos de los fármacos , Astrocitos/inmunología , Astrocitos/metabolismo , Astrocitos/patología , Barrera Hematoencefálica/inmunología , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Western Blotting , Técnicas de Cultivo de Célula , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Corteza Cerebral/inmunología , Corteza Cerebral/metabolismo , Corteza Cerebral/patología , Citocinas/inmunología , Citocinas/metabolismo , Homeostasis/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Carbonilación Proteica/efectos de los fármacos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Based on our recent findings that 25 µM cadmium triggers oxidative stress-mediated caspase-dependent apoptosis in murine thymocytes, this study is designed to explore whether Cd also induces caspase-independent apoptosis. We found that pretreatment with caspase inhibitors fails to prevent Cd-induced apoptosis completely, suggesting the possibility of an additional pathway. Western blot and flow cytometry techniques indicated marked expression of apoptosis-inducing factor and endonuclease G in nuclear fraction, signifying their translocation from mitochondria to nucleus. Intracellular Ca²âº and reactive oxygen species (ROS) levels significantly raised by Cd were restored by ruthenium red, which had no influence on mitochondrial membrane depolarization and caspase activity and apoptosis. Using cyclosporin A, ROS formation and mitochondrial membrane depolarization were completely abolished, whereas apoptosis was partly attenuated. These results clearly demonstrate more than one apoptotic pathway in thymocytes and support the role of mitochondrial permeability transition pore in the regulation of caspase-independent cell death triggered by Cd.
Asunto(s)
Apoptosis/efectos de los fármacos , Cadmio/farmacología , Caspasas/metabolismo , Mitocondrias/metabolismo , Timocitos/efectos de los fármacos , Animales , Factor Inductor de la Apoptosis/metabolismo , Cadmio/toxicidad , Calcio/metabolismo , Inhibidores de Caspasas/farmacología , Ciclosporina/farmacología , Endodesoxirribonucleasas/metabolismo , Humanos , Ratones , Mitocondrias/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: In developing countries especially in south Asia, there are growing habits of consumption of tobacco and its products in various forms. These are known to generate a strong free radical environment and when the free radicals overwhelm the antioxidant system, they may lead to degeneration of cellular components and mutations. AIM: The aim of this study is to assess the levels of oxidative stress determinants, which may be one of the critical factors in head and neck cancer development. MATERIALS AND METHODS: This study included 100 consenting SCCHN patients and 90 matched healthy controls and we assessed the total antioxidant capacity (TAC), glutathione (GSH), free radicals (RNS, ROS) and oxidative DNA adduct (8-OHdG). RESULTS: We observed a substantial rise in reactive oxygen species (ROS, ~3.0-fold) and reactive nitrogen species (RNS, ~1.7-fold), together with significant lowering in TAC (~1.2-fold) and GSH (~1.7-fold) was observed. The 8-OHdG levels were also found to be significantly (P < 0.05) higher in patients in comparison to controls. Pearson's correlation between blood ROS and GSH were found to be negatively correlated -0.38 (P < 0.01) and RNS and DNA damage positively correlated 0.44 (P < 0.01). CONCLUSION: Our present results demonstrate significant Redox imbalance in cancer patients suggesting their paramount importance in the development of SCCHN. The 8-OHdG could be the potential biomarker for evaluating risk of SCCHN. To develop new approaches of SCCHN prevention, there is a need of detailed study and better understanding of the molecular mechanisms underlying oxidative stress and DNA damage.
Asunto(s)
Carcinoma de Células Escamosas/sangre , Daño del ADN , Desoxiguanosina/análogos & derivados , Neoplasias de Cabeza y Cuello/sangre , 8-Hidroxi-2'-Desoxicoguanosina , Adulto , Anciano , Antioxidantes/metabolismo , Carcinoma de Células Escamosas/genética , Estudios de Casos y Controles , Desoxiguanosina/sangre , Glutatión/sangre , Neoplasias de Cabeza y Cuello/genética , Humanos , Persona de Mediana Edad , Oxidantes/sangre , Oxidación-Reducción , Estrés Oxidativo , Especies de Nitrógeno Reactivo/sangre , Especies Reactivas de Oxígeno/sangre , Adulto JovenRESUMEN
Squamous cell carcinoma of head and neck (SCCHN) is the sixth most common cancer globally, and in India, it accounts for 30% of all cancer cases. Epidemiological studies have shown a positive association between defective DNA repair capacity and SCCHN. The underlying mechanism of their involvement is not well understood. In the present study, we have analyzed the relationship between SCCHN and the expression of DNA repair genes namely X-ray repair cross-complementing group 1 (XRCC1), xeroderma pigmentosum group D (XPD), and 8-oxoguanine DNA glycosylase (OGG1) in 75 SCCHN cases and equal number of matched healthy controls. Additionally, levels of DNA adduct [8-hydroxyguanine (8-OHdG)] in 45 SCCHN cases and 45 healthy controls were also determined, to ascertain a link between mRNA expression of these three genes and DNA adducts. The relative expression of XRCC1, XPD, and OGG1 in head and neck cancer patients was found to be significantly low as compared to controls. The percent difference of mean relative expression between cases and controls demonstrated maximum lowering in OGG1 (47.3%) > XPD (30.7%) > XRCC1 (25.2%). A negative Spearmen correlation between XRCC1 vs. 8-OHdG in cases was observed. In multivariate logistic regression analysis (adjusting for age, gender, smoking status, and alcohol use), low expression of XRCC1, XPD, and OGG1 was associated with a statistically significant increased risk of SCCHN [crude odds ratios (ORs) (95%CI) OR 2.10; (1.06-4.17), OR 2.76; (1.39-5.49), and 5.24 (2.38-11.52), respectively]. In conclusion, our study demonstrated that reduced expression of XRCC1, XPD, and OGG1 is associated with more than twofold increased risk in SCCHN.
Asunto(s)
Carcinoma de Células Escamosas/genética , ADN Glicosilasas/genética , Reparación del ADN/genética , Proteínas de Unión al ADN/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias de Cabeza y Cuello/genética , Proteína de la Xerodermia Pigmentosa del Grupo D/genética , Adulto , Anciano , Humanos , Masculino , Persona de Mediana Edad , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos XRESUMEN
Effective DNA repair machinery ensures maintenance of genomic integrity. Environmental insults, ageing and replication errors necessitate the need for proper DNA repair systems. Any alteration in DNA repair efficacy would play a dominant role in progression of squamous cell carcinoma of head and neck (SCCHN). Genotypes of XRCC1 gene-Arg194Trp, Arg280His, Arg399Gln and XPD Lys751Gln, by PCR-RFLP were studied in 278 SCCHN patients and an equal number of matched healthy controls residing in north India. In XRCC1 polymorphisms, Arg194Trp and Arg399Gln variants showed a reduced risk, whereas, XPD Lys751Gln variants exhibited â¼2-fold increase in SCCHN risk. With XRCC1-Arg280His variants, there was no association with SCCHN risk. Arg399Gln of XRCC1 appears to have a protective role in people those consume alcohol, while XPD Lys751Gln variants indicated â¼2-fold increased risk of SCCHN in all the co-variate groups. Comparison of gene-gene interaction among XRCC1 Arg280His and XPD Lys751Gln suggested enhanced risk of SCCHN by â¼2.3-fold in group one and â¼6.1-fold in group two. In dichotomized groups of this combination, the risk was â¼2.4 times. Haplotype analysis revealed the frequency of C-G-G-G and C-A-G-G to be significantly associated with an increased risk of SCCHN. On the contrary, T-G-A-A significantly diminished the risk. CART analysis results showed that the terminal node that contains homozygous mutants of XPD Lys751Gln and XRCC1 Arg194Trp, wild type of XRCC1 Arg399Gln and homozygous mutant of XRCC1 Arg280His, represent the highest risk group. Our results demonstrate high degree of gene-gene interaction involving DNA repair genes of NER and BER pathways, namely XRCC1 and XPD. This study amply demonstrates positive association of XPD Arg751Gln polymorphism with an increased risk of SCCHN. Further, XRCC1 Arg280His variant though dormant individually, may also contribute to the development of cancer in combination with XPD Arg751Gln.
Asunto(s)
Carcinoma de Células Escamosas/genética , Proteínas de Unión al ADN/genética , Neoplasias de Cabeza y Cuello/genética , Estilo de Vida , Proteína de la Xerodermia Pigmentosa del Grupo D/genética , Adulto , Anciano , Carcinoma de Células Escamosas/epidemiología , Estudios de Casos y Controles , Reparación del ADN/genética , Proteínas de Unión al ADN/metabolismo , Progresión de la Enfermedad , Epistasis Genética , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Haplotipos , Neoplasias de Cabeza y Cuello/epidemiología , Humanos , India/epidemiología , Modelos Logísticos , Masculino , Persona de Mediana Edad , Polimorfismo de Longitud del Fragmento de Restricción , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Carcinoma de Células Escamosas de Cabeza y Cuello , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X , Proteína de la Xerodermia Pigmentosa del Grupo D/metabolismoRESUMEN
Squamous cell carcinoma of head and neck (SCCHN), one of the leading cancers worldwide, is most prevalent in Indian sub-continent. The major risk factors involved are smoking and consumption of alcohol, since they provide high free radical generating environment. We studied 8-oxoguanine DNA-glycosylase (OGG1) Ser326Cys polymorphism in 278 SCCHN cases and 278 matched controls by PCR-RFLP and observed that the variant genotype Ser/Cys exhibited an enhanced risk of â¼1.7 folds (OR=1.71, 95% CI=1.20-2.93) and Cys/Cys â¼2.5 folds (OR=2.55, 95% CI=1.29-5.00). Furthermore, we found a significant increase in salivary cell 8-OHdG with respect to Ser/Cys and Cys/Cys genotypes of OGG1 in SCCHN cases, when compared to Ser/Ser and Ser/Cys genotypes of the control population. Our results demonstrate that Ser326Cys variant genotype is associated with an increased risk of SCCHN in north India. Ser326Cys variant genotype was found to accumulate more of 8-OHdG, which may serve as a biomarker for early diagnosis of SCCHN.
Asunto(s)
Carcinoma de Células Escamosas/genética , Daño del ADN , ADN Glicosilasas/genética , Neoplasias de Cabeza y Cuello/genética , Polimorfismo Genético , Adulto , Anciano , Estudios de Casos y Controles , Aductos de ADN , Femenino , Guanina/análogos & derivados , Guanina/metabolismo , Humanos , India , Masculino , Persona de Mediana Edad , Medición de Riesgo , Carcinoma de Células Escamosas de Cabeza y CuelloRESUMEN
Cadmium is a common environmental and occupational hazard and its adverse effect on reproductive organ has been well documented. The present study is planned to delineate the mechanism of Cd toxicity in rat testes. Our study shows that Cd causes apoptosis in sertoli-germ cells which is governed by oxidative stress. We assayed ROS, GSH and MMP to ensure the role of oxidative stress, further confirmed it by thiol modulators. The initial biochemical response shown in sertoli-germ cells was a significant rise in intracellular calcium followed by a drastic fall in MMP and then ROS generation. The downstream events included cytochrome c release leading to caspase-3 activation and culminating in cell death via apoptosis. Furthermore Cd disrupted the spermatogenic pathway as evident by suppression in tesmin and LDH-X levels.
Asunto(s)
Cadmio/toxicidad , Células de Sertoli/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Animales , Caspasa 3/metabolismo , Supervivencia Celular/efectos de los fármacos , Técnicas de Cocultivo , Citocromos c/metabolismo , Daño del ADN , Peroxidación de Lípido/efectos de los fármacos , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Células de Sertoli/metabolismo , Espermatozoides/metabolismoRESUMEN
Spirulina platensis, used worldwide as a food supplement, is a natural source of protein, vitamins, carbohydrates and polyunsaturated fatty acids. C-Phycocyanin (C-Pc), its major biliprotein, is known to possess anti-oxidant, anti-inflammatory and radical scavenging properties. Our present study showed that treatment with C-Pc protects the rats from Tributyltin (TBT) induced thymic atrophy. The results reveal TBT-induced oxidative stress mediated apoptosis in rat thymocytes in vivo and its attenuation by C-Pc. This ameliorative effect could be attributed to antioxidant activity of the biliprotein. C-Pc also increased TBTC reduced thymic weight and cellularity as well. TBTC-induced ROS generation and lowered GSH levels were restored by C-Pc, suggesting its radical scavenging properties. The various apoptotic determinants such as mitochondrial membrane potential, Bax/Bcl-2 ratio, caspase-3 activity and apoptotic cell population were effectively modulated by C-Pc treatment. We make this first observation to illustrate the effectiveness of C-Pc in reducing TBTC-induced thymic atrophy. The morphology of thymic tissue was restored to near normal by this biliprotein. The present study, therefore, suggests that C-Pc could serve as an effective natural antioxidant for efficient management of TBTC induced oxidative damage.
Asunto(s)
Antioxidantes/uso terapéutico , Ficocianina/uso terapéutico , Timo/efectos de los fármacos , Compuestos de Trialquiltina/efectos adversos , Animales , Antioxidantes/farmacología , Apoptosis/efectos de los fármacos , Atrofia/tratamiento farmacológico , Caspasa 3/metabolismo , Citometría de Flujo , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Ficocianina/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Wistar , Timo/patología , Compuestos de Trialquiltina/antagonistas & inhibidores , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Cadmium (Cd), an industrial and environmental pollutant, is toxic to several tissues, most notably causing hepatotoxicity on acute administration and nephrotoxicity following chronic exposure. The therapeutic efficacy of Picroliv--a standardized fraction of Picrorhiza kurroa, was investigated in male rats treated with Cd as CdCl2 (0.5 mg/kg, sc) 5 days/week for 24 weeks and Picroliv at two doses (6 and 12 mg/kg, p.o.) was given during the last 4 weeks. The Cd induced levels of malondialdehyde and membrane fluidity and decreased levels of non protein sulphydryls and Na+K+ATPase activity of hepatic tissue, along with liver function serum enzymes were restored to near normalcy on treatment with the higher dose of Picroliv. Enhanced excretion of urinary proteins, Cd, Ca and enzymes (lactate dehydrogenase and N-acetyl-beta-D-glucosaminidase) evident at 24 weeks of Cd exposure, indicated severe renal damage. Picroliv appeared less effective in causing restoration of these urinary parameters as well as oxidative stress indices in the renal tissue. Picroliv not only reduced the accumulated levels of Cd, Zn and Ca and Cd-metallothionein in liver, but also enhanced the bile flow and biliary Cd. The morphological alterations in liver caused by Cd appeared less marked on Picroliv treatment. However, the renal morphology remained uninfluenced. Our earlier data on 18 weeks of Cd and 4 weeks of Picroliv co-treatment showed significant amelioration of both hepatic and renal manifestations of Cd. The hepatic protection by Picrilov is clearly demonstrated in this study, while marginal lowering of urinary proteins and enzymes is a positive signal of renal protective efficacy of Picroliv, which could be augmented by adopting higher doses and extended regimen.
Asunto(s)
Cadmio/toxicidad , Cinamatos/uso terapéutico , Glicósidos/uso terapéutico , Extractos Vegetales/uso terapéutico , Ácido Vanílico/uso terapéutico , Animales , Cadmio/análisis , Cadmio/orina , Calcio/orina , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/patología , Masculino , Fluidez de la Membrana/efectos de los fármacos , Metalotioneína/análisis , Ratas , ATPasa Intercambiadora de Sodio-Potasio/metabolismoRESUMEN
Cadmium being a potent immunotoxicant, affects both humoral and cell mediated immunity. In rodents, it is primarily characterized by marked thymic atrophy and splenomegaly. Cadmium induces apoptosis in mice and suppresses the immune functions. Piperine, major alkaloid of Piper longum Linn. and Piper nigrum Linn. with a long history of medicinal value, has shown anti-apoptotic activity in vitro. Thus, to delineate its role in vivo, piperine (2.5mg/kg/day, oral, 7 days) treated Balb/C mice were administered Cd as CdCl(2) (1.8mg/kg, i.p., once, 4th day). The various biochemical indexes of cell damage such as cytotoxicity (MTT assay), oxidative stress (glutathione, reactive oxygen species), apoptosis (mitochondrial membrane potential, caspase-3 activity, phosphatidylserine externalization, apoptotic DNA, intranucleosomal DNA fragmentation) along with lymphocyte phenotyping, cell proliferative response and cytokine secretion (IL-2 and IFNγ) were assessed in thymic and splenic single cell suspensions. Lowering of body weight gain and cellularity and a loss in cell viability seen in Cd group, were abrogated by piperine treatment. Similarly, oxidative stress and apoptotic markers altered by Cd were also modulated by this alkaloid. In addition, a pronounced inhibition of cell proliferative response, alterations in T- and B-cell phenotypes, cytokine release and morphological changes were restored to normalcy. The present in vivo data corroborating with our previous in vitro findings, provide confirmatory evidence of the immuno-protective efficacy of piperine.
RESUMEN
Cadmium (Cd), a well known environmental carcinogen, is a potent immunotoxicant. In rodents, it is primarily characterized by marked thymic atrophy and splenomegaly. Cadmium induces apoptosis in murine lymphocytes and alters the immune functions. Thus, for the amelioration of its effect, three structurally different bioactive herbal extracts such as piperine-alkaloid, picroliv-glycosides and curcumin-polyphenols were evaluated and their efficacy compared. For ascertaining their immunomodulatory role, various biochemical indices of cell damage such as cytotoxicity, oxidative stress (ROS, GSH), apoptosis (mitochondrial membrane potential, caspase-3 activity, phosphatidylserine externalization, apoptotic DNA) along with lymphocyte phenotyping, blastogenesis and cytokine secretion were assessed in thymic and splenic cell suspensions. Of the three herbals examined, piperine displayed maximum efficacy. All the three doses of piperine (1, 10 and 50 microg/ml) increased cell viability in a dose dependent manner, whereas curcumin and picroliv were also effective, but to a lesser degree. Only the two higher doses exhibited cell viability efficacy. The median doses ie 10 microg/ml, were therefore selected, for comparison of their antioxidant, anti-apoptotic and immune function modulation. Restoration of ROS and GSH was most prominent with piperine. The anti-apoptotic potential was directly proportional to their antioxidant nature. In addition, Cd altered blastogenesis, T and B cell phenotypes and cytokine release were also mitigated best with piperine. The ameliorative potential was in order of piperine > curcumin > picroliv and former could be considered the drug of choice under immunocompromised conditions.
Asunto(s)
Alcaloides/farmacología , Benzodioxoles/farmacología , Cloruro de Cadmio/toxicidad , Cinamatos/farmacología , Curcumina/farmacología , Glicósidos/farmacología , Piperidinas/farmacología , Alcamidas Poliinsaturadas/farmacología , Ácido Vanílico/farmacología , Animales , Apoptosis/efectos de los fármacos , Linfocitos B/efectos de los fármacos , Caspasa 3/metabolismo , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Glutatión/metabolismo , Interferón gamma/metabolismo , Interleucina-2/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Cadmium (Cd), a possible human carcinogen is a potent immunotoxicant. In rodents it causes thymic atrophy and splenomegaly, in addition to immuno-suppression and modulation of humoral and/or cellular immune response. Oxidative stress and apoptosis appear to be underlying mechanism of Cd induced thymic injury. To understand the involvement of reactive oxygen species (ROS), intracellular glutathione (GSH) and apoptosis in modulation of T-cell repertoire, we studied the effect of Cd (10, 25 and 50 microM) on primary T lymphocytes of BALB/c mice at different time intervals (6, 12 and 18 h). We observed a dose and time dependent decline in CD4(+)/CD8(+) ratio (a bio-indicator of immunotoxicity) as a result of significant suppression of CD4(+)subsets (helper T-cells) and enhancement in CD8(+) cells (cytotoxic T-cells) At the same time, the CD4(+)CD8(+) (DP) cell population was lowered while the CD4(-)CD8(-) (DN) cells were increased. The oxidative stress and apoptotic data revealed almost similar ROS generation in both CD4(+) and CD8(+) cells, but relatively more marked GSH depletion and apoptosis in CD4(+) than in CD8(+) population. On further analysis of CD4(+) T-subsets, cytokine release (IL-2 and IFNgamma) by Th 1 cells and IL-4 by Th 2 cells were shown to be significantly suppressed in a dose responsive manner. The highest inhibition was observed in IFNgamma, then IL-2 followed by IL-4. In conclusion, our data demonstrates that T-cell apoptosis by Cd, more in CD4(+)than in CD8(+)cells appear related to higher depletion of intracellular glutathione. Th 1 cells of CD4(+) sub-population are more responsive to Cd than Th 2, leading to higher suppression of IL-2 and IFNgamma than IL-4 and hence, the study unravels to some extend, the underlying events involved in Cd immunotoxicity.