Lead and zinc interactions - An influence of zinc over lead related toxic manifestations.

BACKGROUND: Interaction between metals is known from earlier studies, in which one metal influences the absorption and functional role of other. Lead is known to cause debilitating effects in living organisms and also prevents several essential trace metals from functioning normally. METHODS: The relevant literature using the key words lead toxicity, lead zinc interaction, zinc nutrition and the ability of zinc to act against lead has been reviewed. RESULTS: Role of several nutrients in reducing the manifestations of toxic metals have been elucidated recently. Lead damages bio-membranes, causes cognitive disabilities and disturbs the normal process of DNA replication and transcription. Zinc on the other hand helps in proper maintenance of the cellular membranes and plays an important role as a metal cofactor in most of the proteins vital for membrane integrity. Zinc has essential role in cognitive functioning, zinc finger proteins and significantly neutralizes most toxic effects of lead. CONCLUSION: Increased lead exposure and limited resources for tackling lead poisoning may cause an increased possibility of future environmental emergencies. Interactions between essential nutrient metals and non-essential toxic metals may act as important factor which can be used to target the metal toxicities. An assumption is made that the lead toxicity can be reduced by maintaining the status of essential trace metals like zinc.

Influence of zinc levels on the toxic manifestations of lead exposure among the occupationally exposed workers.

Lead and zinc are usually found at the same occupational places and occur as co-contaminants. Effects of lead toxicity are detrimental on human health as it is probable carcinogen and impairs normal growth and development. On the other hand, zinc is an important nutritional element, the deficiency of which causes debilitating effects on growth and development. The purpose of this study was to examine the possible association of blood lead and zinc levels and any influence of zinc over DNA damage, blood cell membrane aberration and oxidative stress among lead and zinc co-exposed workers. Atomic absorption spectroscopy was used for lead and zinc measurement and comet assay for DNA damage assessment. Haematological aberrations were studied using light and electron microscopy (LM and EM) followed by electron density X-ray spectroscopy (EDS) and elemental mapping. Occupational exposure was observed to cause significant elevation in blood lead levels among workers. This elevation in lead levels and associated DNA damage among workers was significantly high in comparison to controls. Further light and electron micrographs of red blood cells revealed significant morphological alterations associated with increased lead ions in workers. It was clear from SEM-based elemental maps and EDS graphs that elevated lead levels were associated with low levels of zinc. The results suggest that lead absorption is highly influenced due to zinc levels in body which has an impact over DNA damage, blood cell aberration and oxidative stress caused by lead exposure. Efforts are going on to understand the role of other trace metals on lead toxicity in order to develop a sustainably nutrition-based therapeutic intervention. Graphical abstract.

Evaluation of DNA interaction, genotoxicity and oxidative stress induced by iron oxide nanoparticles both in vitro and in vivo: attenuation by thymoquinone.

Iron oxide nanoparticles (IONPs) are known to induce cytotoxicity in various cancer cell lines through the generation of reactive oxygen species (ROS). However, the studies on its potential to induce toxicity in normal cell lines and in vivo system are limited and ambiguity still exists. Additionally, small molecules are known to interact with the DNA and cause damage to the DNA. The present study is designed to evaluate the potential interaction of IONPs with DNA along with their other toxicological effects and subsequent attenuation by thymoquinone both in vitro (primary lymphocytes) and in vivo (Wistar rats). IONPs were characterized by TEM, SEM-EDS, and XRD. The results from DNA interaction studies showed that IONPs formed a complex with DNA and also got intercalated between the base pairs of the DNA. The decrease in percent cell viability of rat's lymphocytes was observed along with an increase in ROS generation in a dose-dependent manner (50, 100, 200, 400 and 800 µg/ml of IONPs). The genetic damage in in vivo might be due to the generation of ROS as depletion in anti-enzymatic activity was observed along with an increase in lipid peroxidation in a dose-dependent manner (25, 50, 100 mg/kg of IONPs). Interestingly, supplementation of thymoquinone in combination with IONPs has significantly (P < 0.05) attenuated the genetic and oxidative damage in a dose-dependent manner both in vitro and in vivo. It can be concluded that thymoquinone has the potential to attenuate the oxidative stress and genetic toxicity in vitro and in vivo.

Brain, behavior and the journey towards neuroepigenetic therapeutics.

Epigenetics has brought about a major shift in our understanding of biological mechanisms and their associated health effects. Strong epigenetic components have been found to be involved in the progression of many diseases. In several human diseases, including debilitating psychiatric disorders, altered epigenetic status has been found as one of the main causes. With continuous progress on drug development, researchers are enthusiastic toward epigenetic therapeutics which could possibly reverse epigenetic modifications. In this article certain developments in epigenetic therapeutics are highlighted, the indiscriminate use of which could also be associated with potential risk. These risks may partly be due to our limited knowledge on genes and the mechanisms underlying epigenetic involvement in different diseases. Epigenetic changes are fundamentally important for a large number of bodily functions; nonspecific usage of therapeutics could be potentially harmful therefore there is a need to harness epigenetics positively.

Protective role of nimbolide against chemotherapeutic drug hydroxyurea induced genetic and oxidative damage in an animal model.

Nimbolide is known to be an antioxidant found in neem plant. Hydroxyurea is a medication frequently used in sickle-cell disease, different cancers and HIV infection. The present study aimed to evaluate the adverse effect of HU and possible amelioration by nimbolide in Wistar rats. To test our hypothesis, we performed genotoxicity tests, biochemical assays, and histopathological studies. We observed that HU caused higher levels of genotoxicity in the treated animals. The observed genetic and oxidative damage might be due to the presence of reactive species as HU increased the level of the malondialdehyde-a biomarker of oxidative damage. Interestingly, co-treatment of animals with HU and nimbolide showed a lower level of damage. We conclude that nimbolide significantly protects the cells from the adverse effect of HU and could be considered as a potential adjuvant for the patients under HU therapy.

Understanding adult neurogenesis beyond its role in learning and memory formation / Comprendiendo la neurogénesis adulta más allá de su papel en la formación del aprendizaje y la memoria

There has been a shift in the understanding of brain, neurons, and their functional role over the last two decades. Earlier it was believed that the brain was a static organ and was not subject to any change throughout life. An understanding was developed later that brain reorganizes its structure by a specific property called neuroplasticity. Recent research shows that the brain generates new neurons even in the adult stage, and this process is called adult neurogenesis. Although researchers still not have all the answers about the newborn neurons, and why and how they are generated, and what is their role, some have highlighted the importance of these in learning and memory formation, and even in memories of fear and spatial navigation. A wide range of environmental experience influences the generation of newborn neurons and their functional variability. There are questions about how different environmental experiences cause the differences in the generation of new neurons. Recently the field of optogenetics attempted to answer the questions on adult neurogenesis. However there are still questions about adult neurogenesis which needs a more naturalistic approach, for their better understanding

No ha habido un cambio en la comprensión del cerebro, las neuronas y su papel funcional de las últimas 2 décadas. Anteriormente se creía que el cerebro es un órgano estático y no está sujeto a ningún cambio durante toda la vida. La comprensión se desarrolló más tarde, que el cerebro reorganiza su estructura por una propiedad específica llamada neuroplasticidad. Investigaciones recientes muestran que el cerebro genera nuevas neuronas, incluso en la etapa adulta, y este proceso se llama neurogénesis adulta. Aunque por ahora los investigadores no tienen todas las respuestas sobre las nuevas neuronas nacidas y por qué y cómo se generan, y cuál es su papel. Algunos han puesto de relieve la importancia de las neuronas recién nacidas en la formación del aprendizaje y la memoria, e incluso en los recuerdos de miedo y la navegación espacial. Una amplia gama de experiencia ambiental influye en la generación de neuronas recién nacidas y su variabilidad funcional. Hay preguntas acerca de cómo la variada experiencia ambiental ocasiona diferencias en la generación de nuevas neuronas. Recientemente, el campo de la optogenética intentó responder a las preguntas sobre la neurogénesis adulta. Sin embargo, todavía hay preguntas sobre la neurogénesis adulta que necesitan de un enfoque más naturalista para su mejor comprensión

Possible role of zinc in diminishing lead-related occupational stress-a zinc nutrition concern.

Lead and zinc are mostly present at the same occupational source and usually found as co-contaminants. Lead is known to associate with detrimental effects to humans. Zinc however is an essential nutrient and its deficiency causes debilitating effects on growth and development. Besides, it acts as core ion of important enzymes and proteins. The purpose of this study was to examine if zinc concentrations are associated with blood lead levels and if zinc may prevent lead-induced DNA damage. Blood samples were collected from 92 workers as participants occupationally exposed to lead or lead and zinc and 38 comparison participants having no history of such exposure. Lead and zinc levels were determined from blood by atomic absorption spectrophotometry and genetic damage was assessed by comet assay. Correlation was calculated by Spearman's rho. Lead concentrations were observed to increase among workers with increase in years of exposure. There was a significant difference (p < 0.001) in blood lead levels between workers and controls. In addition, significant difference (p < 0.001) in the genetic damage was observed among workers and controls. A clear effect of increased occupational exposure was visible among workers. Multiple regression analysis further reveals the positive effect of lead, while as the inverse effect of zinc on DNA damage. The results suggest that zinc may influence body lead absorption and may have a role in preventing the genetic damage caused by lead.

Omega-3 fatty acids and the treatment of depression: a review of scientific evidence.

Depression is a condition in which an individual feels lethargic, irritable, and guilty, has difficulty and trouble, no enjoyment in life, mood swings, sometimes suicidal ideation and thoughts, and loss of pleasure in activities. There are hundreds of millions of individuals suffering from major depression disorder all over the world. This leads to a considerable portion of the economy going for treatment as large amounts of money are spent on drugs every year. Pharmaceutical drugs are not very effective and they also have side effects that compound the problem. There are number of studies which shows that omega-3 fatty acids are proving to be very effective against the treatment of major depression disorder and other psychiatric disorders. However, the data regarding the efficacy of omega-3 fatty acids in depression treatment are conflicted. This article reviews the recent research showing the relation between omega-3 fatty acids and depression. The roles of the omega-3 fatty acids in the treatment of depression are being studied with increased pace in the last decade due to heightened prevalence of depression. It is emphasized that omega-3 fatty acids have no record of associated side effects, which deserves greater attention for further research.

Lead toxicity: a review.

Lead toxicity is an important environmental disease and its effects on the human body are devastating. There is almost no function in the human body which is not affected by lead toxicity. Though in countries like US and Canada the use of lead has been controlled up to a certain extent, it is still used vehemently in the developing countries. This is primarily because lead bears unique physical and chemical properties that make it suitable for a large number of applications for which humans have exploited its benefits from historical times and thus it has become a common environmental pollutant. Lead is highly persistent in the environment and because of its continuous use its levels rise in almost every country, posing serious threats. This article reviews the works listed in the literature with recent updates regarding the toxicity of lead. Focus is also on toxic effects of lead on the renal, reproductive and nervous system. Finally the techniques available for treating lead toxicity are presented with some recent updates.

Blood injury and injection phobia: the neglected one.

Blood injury and injection (BII) phobia is a unique phobia associated with a diphasic cardiovascular response. The aim of this survey was to report the prevalence of BII phobia, its heritability, and clinical characteristics among the males and females in the Indian subcontinent. An interview and a survey were conducted using a developed BII phobia 21-item questionnaire among 3261 participant males (n = 1648) and females (n = 1613). Cronbach' alpha (α) of 0.972 of internal consistency was reported. The prevalence of BII phobia and associated fainting in females was slightly more than double in the males with a significant gender related effect. Similar avoidance behaviours involving hospital visits were reported for both males and females. The relative frequency of BII phobia among first and third degree relatives was found to be higher than among second degree relatives. Depression was found highly comorbid with BII phobia while a low rate of obsessive compulsion disorder (OCD) and social anxiety disorder (SAD) was reported. Morbidity associated with BII phobia may increase dramatically when other medical problems coincide with it.