Arsenic-Induced Antioxidant Depletion, Oxidative DNA Breakage, and Tissue Damages are Prevented by the Combined Action of Folate and Vitamin B12

Metabolism of inorganic arsenic in mice carrying the human AS3MT gene and fed folate deficient or folate supplemented diet

Arsenic (+3 oxidation state) methyltransferase (AS3MT) catalyzes the S-adenosylmethionine (SAM)-dependent methylation of inorganic arsenic (iAs), yielding monomethyl‑arsenic (MAs) and dimethyl‑arsenic (DMAs) metabolites. The formation of DMAs in this pathway is considered a key mechanism for iAs detoxification. Availability of SAM for iAs methylation depends in part on dietary intake of folate. Results of population studies suggest that supplementation with folate stimulates iAs methylation, increasing DMAs and decreasing iAs and MAs proportions in urine and/or blood. The goal of the present study was to determine if folate intake affects methylation and clearance of iAs in a recently established mouse strain that expresses human AS3MT and exhibits a human-like pattern of iAs metabolism. The humanized male and female mice were fed folate-deficient (FD) or folate-supplemented (FS) diet for 6 weeks, followed by exposure to 0 ppb or 400 ppb iAs in drinking water for 5 weeks, while on the same types of diet. The concentrations and proportions of iAs, MAs and DMAs were determined in urine, liver, kidneys, and spleen. The diet-, sex- and dose-related differences were assessed by t-test or a non-parametric test; Bonferroni test was used to correct for multiple comparisons. In general, proportions of DMAs were greater and proportions of iAs were smaller in urine and tissues of FS mice as compared to FD mice. However, folate supplementation also increased MAs proportions. Notably, the folate intake had no effect on the concentrations of total arsenic either in the urine or the tissues. These results suggest that, similar to humans, folate supplementation stimulates iAs methylation in the humanized mice. However, the stimulation of iAs methylation is not associated with clearance of arsenic from tissues, possibly due to an inefficient conversion of MAs to DMAs.

Integration of proteomics and metabolomics analysis investigate mechanism of As-induced immune injury in rat spleen

Arsenic (As) is a widespread metalloid and human carcinogen found in the natural environment, and multiple toxic effects have been shown to be associated with As exposure. As can be accumulated in the spleen, the largest peripheral lymphatic organ, and long-term exposure to As can lead to splenic injury. In this study, a Sprague-Dawley (SD) rat model of As-poisoned was established, aiming to explore the molecular mechanism of As-induced immune injury through the combined analysis of proteomics and metabolomics of rats' spleen. After feeding the rats with As diet (50 mg/kg) for 90 days, the spleen tissue of the rats in the As-poisoned group was damaged, the level of As was significantly higher than that of the control group (P < 0.001), and the level of inflammatory cytokine interleukin-6 (IL-6) was decreased (P < 0.01). Proteomics and metabolomics results showed that a total of 134 differentially expressed proteins (DEPs) (P < 0.05 and fold change > 1.2) and 182 differentially expressed metabolites (DEMs) (VIP >1 and P < 0.05) were identified in the spleens of the As poisoned group compared to the control group (As/Ctrl). The proteomic results highlight the role of hypoxia-inducible factors (HIF), natural killer cell mediated cytotoxicity, and ribosomes. The major pathways of metabolic disruption included arachidonic acid (AA) metabolism, glycerophospholipid metabolism and folate single-carbon pool. The integrated analysis of these two omics suggested that Hmox1, Stat3, arachidonic acid, phosphatidylcholine and leukotriene B4 may play key roles in the mechanism of immune injury to the spleen by As exposure. The results indicate that As exposure can cause spleen damage in rats. Through proteomic and metabolomic analysis, the key proteins and metabolites and their associated mechanisms were obtained, which provided a basis for further understanding of the molecular mechanism of spleen immune damage caused by As exposure.

Assessing groundwater quality and its association with child undernutrition in India

BACKGROUND AND OBJECTIVES

Groundwater contamination poses a significant health challenge in India, particularly impacting children. Despite its importance, limited research has explored the nexus between groundwater quality and child nutrition outcomes. This study addresses this gap, examining the association between groundwater quality and child undernutrition, offering pertinent insights for policymakers.

DATA AND METHODS

The study uses data from the fifth round of the National Family Health Survey (NFHS) and the Central Groundwater Board (CGWB) to analyze the association between groundwater quality and child nutritional status. The groundwater quality data were collected by nationwide monitoring stations programmed by CGWB, and the child undernutrition data were obtained from the NFHS-5, 2019-21. The analysis included descriptive and logistic regression model. The study also considers various demographic and socio-economic factors as potential moderators of the relationship between groundwater quality and child undernutrition.

FINDINGS

Significant variation in groundwater quality was observed across India, with numerous regions displaying poor performance. Approximately 26.53 % of geographical areas were deemed unfit for consuming groundwater. Environmental factors such as high temperatures, low precipitation, and arid, alluvial, laterite-type soils are linked to poorer groundwater quality. Unfit-for-consumption groundwater quality increased the odds of undernutrition, revealing a 35 %, 38 %, and 11 % higher likelihood of stunting, underweight, and wasting in children, with higher pH, Magnesium, Sulphate, Nitrate, Total Dissolved Solids, and Arsenic, levels associated with increased odds of stunting, underweight, and wasting. Higher temperatures (>25 °C), high elevations (>1000 m), and proximity to cultivated or industrial areas all contribute to heightened risks of child undernutrition. Children consuming groundwater, lacking access to improved toilets, or living in rural areas are more likely to be undernourished, while females, higher-income households, and those consuming dairy, vegetables, and fruits daily exhibit lower odds of undernutrition.

POLICY IMPLICATIONS

Policy implications highlight the urgent need for investment in piped water supply systems. Additionally, focused efforts are required to monitor and improve groundwater quality in regions with poor water quality. Policies should emphasize safe sanitation practices and enhance public awareness about the critical role of safe drinking water in improving child health.

n-Butanol fraction of moringa seed attenuates arsenic intoxication by regulating the uterine inflammatory and apoptotic pathways

The adverse effects of arsenic-chelating drugs make it essential to replace invasive chelating therapy with non-invasive oral therapy for arsenic poisoning. The goal of the current investigation was to determine whether the uterine damage caused by arsenization could be repaired by the n-butanol fraction of Moringa oleifera seed (NB). The rats were orally administered with arsenic (10 mg/kg BW) for the initial 8 days, followed by NB (50 mg/kg) for the next 8 days without arsenic. The probable existence of different components in NB was evaluated by HPLC-MS. Pro and anti-inflammatory indicators were assessed by RT-PCR and western blot. ESR-α was detected via immunostaining. Arsenic-exposed rats had significantly increased lipid peroxidation and decreased antioxidant enzyme activity, which were markedly reduced after NB treatment. Weaker ESR-α expression and distorted uterine histomorphology following arsenication were retrieved significantly by NB. Meaningful restoration by NB was also achieved for altered mRNA and protein expression of various inflammatory and apoptotic indicators. Molecular interaction predicted that glucomoringin and methyl glucosinolate of moringa interact with the catalytic site of caspase-3 in a way that limits its activity. However, NB was successful in restoring the arsenic-mediated uterine hypofunction. The glucomoringin and methyl glucosinolate present in n-butanol fraction may play a critical role in limiting apoptotic event in the arsenicated uterus.

Abnormal Phenylalanine Metabolism of Procapra przewalskii in Chronic Selenosis in Selenium-Enriched Habitats

Selenium (Se)-enriched habitats have led to chronic selenosis, seriously affecting the health and survival of Procapra przewalskii (P. przewalskii). Our targets were to explore the molecular mechanisms of chronic selenosis and to look for a new way to protect endangered species. The mineral contents of soils, grass, blood, and muscle were analyzed. The biochemical indices, antioxidant capability, and immune function were also investigated. The analyses of proteomics and metabolomics were also carried out. The results showed that the Se contents in the muscle and blood of P. przewalskii, and the soil and grass in the Se-enriched habitats were significantly higher than those in healthy pastures. The P. przewalskii in the Se-enriched habitats showed symptoms of anemia, decreased antioxidant capability, and low immune function. A total of 44 differential proteins and 36 differential metabolites were screened by analyzing their proteomics and metabolomics. These differential proteins and metabolites were involved in glycolysis pathway, amino acid biosynthesis, carbon metabolism, phenylalanine metabolism, and energy metabolism. In particular, phenylalanine metabolism was the common pathway of proteomics and metabolomics, which was an important finding in studying the mechanism of chronic selenosis in animals. This study will help us to further understand the mechanism of chronic selenosis in P. przewalskii, and it provides a scientific basis for the protection of endangered species in Se-enriched habitats.

Vitamin B12-Multifaceted In Vivo Functions and In Vitro Applications

Vitamin B12 plays a key role in DNA stability. Research indicates that vitamin B12 deficiency leads to indirect DNA damage, and vitamin B12 supplementation may reverse this effect. Vitamin B12 acts as a cofactor for enzymes such as methionine synthase and methylmalonyl-CoA mutase, which are involved in DNA methylation and nucleotide synthesis. These processes are essential for DNA replication and transcription, and any impairment can result in genetic instability. In addition, vitamin B12 has antioxidant properties that help protect DNA from damage caused by reactive oxygen species. This protection is achieved by scavenging free radicals and reducing oxidative stress. In addition to their protective functions, cobalamins can also generate DNA-damaging radicals in vitro that can be useful in scientific research. Research is also being conducted on the use of vitamin B12 in medicine as vectors for xenobiotics. In summary, vitamin B12 is an essential micronutrient that plays a vital role in DNA stability. It acts as a cofactor for enzymes involved in the synthesis of nucleotides, has antioxidant properties and has potential value as a generator of DNA-damaging radicals and drug transporters.

Influence of Dietary Compounds on Arsenic Metabolism and Toxicity. Part I-Animal Model Studies

Population and laboratory studies indicate that exposure to various forms of arsenic (As) is associated with many adverse health effects; therefore, methods are being sought out to reduce them. Numerous studies focus on the effects of nutrients on inorganic As (iAs) metabolism and toxicity, mainly in animal models. Therefore, the aim of this review was to analyze the influence of methionine, betaine, choline, folic acid, vitamin B₂, B₆, B₁₂ and zinc on the efficiency of iAs metabolism and the reduction of the severity of the whole spectrum of disorders related to iAs exposure. In this review, which includes 58 (in vivo and in vitro studies) original papers, we present the current knowledge in the area. In vitro and in vivo animal studies showed that methionine, choline, folic acid, vitamin B₂, B₁₂ and zinc reduced the adverse effects of exposure to iAs in the gastrointestinal, urinary, lymphatic, circulatory, nervous, and reproductive systems. On the other hand, it was observed that these compounds (methionine, choline, folic acid, vitamin B₂, B₁₂ and zinc) may increase iAs metabolism and reduce toxicity, whereas their deficiency or excess may impair iAs metabolism and increase iAs toxicity. Promising results of in vivo and in vitro on animal model studies show the possibility of using these nutrients in populations particularly exposed to As.

Prenatal Environmental Metal Exposure and Preterm Birth: A Scoping Review

Preterm birth (PTB) and its complications are the leading causes of under-five year old child deaths, accounting worldwide for an estimated one million deaths annually. The etiology of PTB is complex and multifactorial. Exposures to environmental metals or metalloids are pervasive and prenatal exposures to them are considered important in the etiology of PTB. We conducted a scoping review to determine the extent of prenatal exposures to four metals/metalloids (lead, mercury, cadmium and arsenic) and their association with PTB. We reviewed original research studies published in PubMed, Embase, the Cochrane Library, Scopus, POPLINE and the WHO regional indexes from 2000 to 2019; 36 articles were retained for full text review. We documented a higher incidence of PTB with lead and cadmium exposures. The findings for mercury and arsenic exposures were inconclusive. Metal-induced oxidative stress in the placenta, epigenetic modification, inflammation, and endocrine disruptions are the most common pathways through which heavy metals and metalloids affect placental functions leading to PTB. Most of the studies were from the high-income countries, reflecting the need for additional data from low-middle-income countries, where PTB rates are higher and prenatal exposure to metals are likely to be just as high, if not higher.

Mitigation of arsenic driven utero-ovarian malfunction and changes of apoptotic gene expression by dietary NAC

An oral painless dietary therapy is also indispensable in the management of arsenic toxicity despite of its conventional painful therapeutic management. The present study focused on the management of arsenic mediated female reproductive dysfunctions by dietary therapy of N-acetyl cysteine (NAC). Here, sodium arsenite was given at the dose of 10 mg/kg body weight orally for the first 8 day. Day 9 onwards up to day 16 these arsenicated rats were provided with NAC (250 mg/kg body weight) enriched basal diet once daily. Arsenic intoxicated group exhibited a comparable inactivation of antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) due to oxidative stress in reproductive organs along with a simultaneous elevation of lipid peroxidation state and decline in non-protein soluble thiols (NPSH) level in female reproductive organs. Arsenic intoxication also accomplished with the up-regulation of inflammatory markers tumour necrosis factor (TNF α) and nuclear factor κB (NF κB). Pro-apoptotic Bax gene and p53 gene expressions were also raised due to arsenic intoxication while anti-apoptotic Bcl-2 gene expression was suppressed. In fact, arsenication decreased the circulating level of vitamin B12 and folic acid. Dietary NAC supplementation significantly reversed back the activity of antioxidant enzymes in arsenite fed rats towards normalcy and also sustained the normal reproductive cyclicity, utero-ovarian histo-morphology and estradiol receptor α (ER-α) expression in these reproductive organs. Dietary NAC exerted its positive action against arsenic intoxication by up-regulation of Bcl-2 gene expression along with the suppression of pro-apoptotic Bax gene and p53 gene. Thus, dietary NAC also plays anti-apoptotic, anti-inflammatory, and anti-oxidative role against arsenic toxicity. NAC also regulates the components (vitamin B12 and folic acid) of S-adenosylmethionine pool in the way of probable removal of arsenic from the system.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.

Zinc Deficiency and Arsenic Exposure Can Act Both Independently or Cooperatively to Affect Zinc Status, Oxidative Stress, and Inflammatory Response

The negative health impact of zinc deficiency overlaps significantly with arsenic exposure, and is associated with increased risk for chronic diseases. Arsenic contamination in the groundwater often co-exists in regions of the world that are prone to zinc deficiency. Notably, low zinc status shares many hallmarks of arsenic exposure, including increased oxidative stress and inflammation. Despite their common targets and frequent co-distribution in the population, little is known regarding the interaction between zinc deficiency and arsenic exposure. In this study, we tested the effect of arsenic exposure at environmentally relevant doses in combination with a physiologically relevant level of zinc deficiency (marginal zinc deficiency) on zinc status, oxidative damage, and inflammation. In cell culture, zinc-deficient THP-1 monocytes co-exposed with arsenic resulted in further reduction in intracellular zinc, as well as further increase in oxidative stress and inflammatory markers. In an animal study, zinc-deficient mice had further decrease in zinc status when co-exposed to arsenic. Zinc deficiency, but not arsenic exposure, resulted in an increase in baseline transcript abundance of inflammatory markers in the liver. Upon lipopolysaccharide challenge to elicit an acute inflammatory response, arsenic exposure, but not zinc deficiency, resulted in an increase in proinflammatory response. In summary, zinc deficiency and arsenic exposure can function independently or cooperatively to affect zinc status, oxidant stress, and proinflammatory response. The results highlight the need to consider both nutritional status and arsenic exposures together when considering their impact on health outcomes in susceptible populations.

Association of Vitamin B12, Lactate Dehydrogenase, and Regulation of NF-κB in the Mitigation of Sodium Arsenite-Induced ROS Generation in Uterine Tissue by Commercially Available Probiotics

Managing arsenic intoxication with conventional metal chelators is a global challenge. The present study demonstrated the therapeutic role of probiotics against arsenic-induced oxidative stress and female reproductive dysfunction. Sodium arsenite-treated (1.0 mg/100 g body weight) Wistar female rats were followed up by a post-treatment of commercially available probiotic mixture in powder form (0.25 mg/100 g body weight) orally. Rats that experienced arsenic ingestion showed a significant lessening in the activities of uterine superoxide dismutase (SOD), catalase activities, and the level of non-protein soluble thiol (NPSH) with a concomitant increase in malondialdehyde (MDA) and conjugated dienes (CD). Exposure to arsenic significantly lowered the levels of vitamin B₁₂ and estradiol. Exposure to arsenic highly expressed the inflammatory marker and transcription factor NF-κB. Arsenic-mediated instability of these above parameters was controlled by the probiotics with a rebuilding of better function of anti-oxidant components. Besides its function in regulating endogenous anti-oxidant system, probiotics were able to augment the protection against mutagenic uterine DNA-breakage, necrosis, and ovarian-uterine tissue damages in arsenicated rats.

Spirulina platensis ameliorates arsenic-mediated uterine damage and ovarian steroidogenic disorder

Novel, non-invasive, painless oral therapeutic agents are needed to replace the painful conventional treatment of arsenic-associated health hazards with metal chelators. Our aim was to examine the effect of spirulina ( Spirulina platensis ( Geitler, 1925 )) on arsenic-mediated uterine toxicity. Female Wistar rats were divided equally into four experimental treatment groups: control group, sodium arsenite group (1.0 mg/100 g body mass), spirulina placebo group (20 mg/100 g body mass), and sodium arsenite + spirulina group. In contrast with the control group, spectrophotometric and electrozymographic evaluation revealed that rats that ingested arsenic for 8 d showed significant diminution of the activities of superoxide dismutase, catalase, and peroxidase ( p < 0.001). Mutagenic uterine DNA breakage and tissue damage were prominent following arsenic consumption by the rats. Oral delivery of spirulina resulted in a significant amelioration of arsenic-induced adverse oxidative stress and genotoxic state of rats. A significant low-signaling ( p < 0.001) of gonadotropins and estradiol was also noted in the arsenic-treated rats, which was terminated by spirulina; this arsenic-primed adverse effect was significant ( p < 0.05, p < 0.01). The spirulina treatment mechanism could be associated with augmentation of the antioxidant defense system that protects the arsenic-mediated pathological state of the uterus.

Prenatal arsenic exposure and dietary folate and methylcobalamin supplementation alter the metabolic phenotype of C57BL/6J mice in a sex-specific manner

Inorganic arsenic (iAs) is an established environmental diabetogen. The link between iAs exposure and diabetes is supported by evidence from adult human cohorts and adult laboratory animals. The contribution of prenatal iAs exposure to the development of diabetes and underlying mechanisms are understudied. The role of factors that modulate iAs metabolism and toxicity in adults and their potential to influence diabetogenic effects of prenatal iAs exposure are also unclear. The goal of this study was to determine if prenatal exposure to iAs impairs glucose metabolism in mice and if maternal supplementation with folate and methylcobalamin (B12) can modify this outcome. C57BL/6J dams were exposed to iAs in drinking water (0, 100, and 1000 µg As/L) and fed a folate/B12 adequate or supplemented diet from before mating to birth of offspring. After birth, dams and offspring drank deionized water and were fed the folate/B12 adequate diet. The metabolic phenotype of offspring was assessed over the course of 14 weeks. Male offspring from iAs-exposed dams fed the folate/B12-adequate diet developed fasting hyperglycemia and insulin resistance. Maternal folate/B12 supplementation rescued this phenotype but had only marginal effects on iAs metabolism in dams. The diabetogenic effects of prenatal iAs exposure in male offspring were not associated with changes in global DNA methylation in the liver. Only minimal effects of prenatal iAs exposure or maternal supplementation were observed in female offspring. These results suggest that prenatal iAs exposure impairs glucose metabolism in a sex-specific manner and that maternal folate/B12 supplementation may improve the metabolic phenotype in offspring. Further studies are needed to identify the mechanisms underlying these effects.

Toxicodynamics of Lead, Cadmium, Mercury and Arsenic- induced kidney toxicity and treatment strategy: A mini review

Environmental pollution has become a concerning matter to human beings. Flint water crisis in the USA pointed out that pollution by heavy metal is getting worse day by day, predominantly by Lead, Cadmium, Mercury and Arsenic. Despite of not having any biological role in flora and fauna, they exhibit detrimental effect following exposure (acute or chronic). Even at low dose, they affect brain, kidney and heart. Oxidative stress has been termed as cause and effect in heavy metal-induced kidney toxicity. In treatment strategy, different chelating agent, vitamins and minerals are included, though chelating agents has been showed different fatal drawbacks. Interestingly, plants and plants derived compounds had shown possible effectiveness against heavy metals induced kidney toxicity. This review will provide detail information on toxicodynamics of Pb, Cd, Hg and As, treatment strategy along with the possible beneficiary role of plant derived compound to protect kidney.

Prenatal arsenic exposure and dietary folate and methylcobalamin supplementation alter the metabolic phenotype of C57BL/6J mice in a sex-specific manner

Inorganic arsenic (iAs) is an established environmental diabetogen. The link between iAs exposure and diabetes is supported by evidence from adult human cohorts and adult laboratory animals. The contribution of prenatal iAs exposure to the development of diabetes and underlying mechanisms are understudied. The role of factors that modulate iAs metabolism and toxicity in adults and their potential to influence diabetogenic effects of prenatal iAs exposure are also unclear. The goal of this study was to determine if prenatal exposure to iAs impairs glucose metabolism in mice and if maternal supplementation with folate and methylcobalamin (B12) can modify this outcome. C57BL/6J dams were exposed to iAs in drinking water (0, 100, and 1000 µg As/L) and fed a folate/B12 adequate or supplemented diet from before mating to birth of offspring. After birth, dams and offspring drank deionized water and were fed the folate/B12 adequate diet. The metabolic phenotype of offspring was assessed over the course of 14 weeks. Male offspring from iAs-exposed dams fed the folate/B12-adequate diet developed fasting hyperglycemia and insulin resistance. Maternal folate/B12 supplementation rescued this phenotype but had only marginal effects on iAs metabolism in dams. The diabetogenic effects of prenatal iAs exposure in male offspring were not associated with changes in global DNA methylation in the liver. Only minimal effects of prenatal iAs exposure or maternal supplementation were observed in female offspring. These results suggest that prenatal iAs exposure impairs glucose metabolism in a sex-specific manner and that maternal folate/B12 supplementation may improve the metabolic phenotype in offspring. Further studies are needed to identify the mechanisms underlying these effects.

Arjunolic Acid Improves the Serum Level of Vitamin B12 and Folate in the Process of the Attenuation of Arsenic Induced Uterine Oxidative Stress

Continuation of prolonged treatment against arsenicosis with conventional chelating therapy is a global challenge. The present study was intended to evaluate the defensive effect of arjunolic acid against arsenic-induced oxidative stress and female reproductive dysfunction. Wistar strain adult female rats were given sodium arsenite (10 mg/kg body weight) in combination with arjunolic acid (10 mg/kg body weight) orally for two estrous cycles. Electrozymographic analysis explored that arjunolic acid co-treatment counteracted As³⁺-induced ROS production in uterine tissue by stimulating the activities of endogenous enzymatic antioxidants. Arjunolic acid was able to enhance the protection against mutagenic uterine DNA breakage, necrosis, and ovarian-uterine tissue damages in arsenicated rats by improving the ovarian steroidogenesis. The mechanisms might be coupled with the augmentation of antioxidant defense system, partly through the elimination of arsenic with the involvement of S-adenosyl methionine pool where circulating levels of vitamin B₁₂, folic acid, and homocysteine play critical roles as evidenced from our present investigation.

The consequence of NAC on sodium arsenite-induced uterine oxidative stress

Arsenic consumption through drinking water is a worldwide major health problem. Management of arsenic intoxication with invasive, painful therapy using metal chelators is usually used as a conventional treatment strategy in human. In this present study, we examined the efficacy of oral administration of N-acetyl l-cysteine (NAC) in limiting arsenic-mediated female reproductive disorders and oxidative stress in female Wistar rats. The treatment was continued for 8 days (2 estrus cycles) on rats with sodium arsenite (10 mg/Kg body weight) orally. We examined the electrozymographic imprint of three different enzymatic antioxidants in uterine tissue. Rats fed with sodium arsenite exhibited a significant lessening in the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx). Uterine DNA breakage, necrosis, ovarian and uterine tissue damage, disruption in steroidogenesis were also found in arsenic treated rats. Co-administration of NAC at different doses (50 mg/kg body weight, 100 mg/kg body weight, respectively) significantly reversed the action of uterine oxidative stress markers like malondialdehyde (MDA), conjugated dienes (CD) and non protein soluble thiol (NPSH); and noticeably improved antioxidant status of the arsenic fed rats. This ultimately resulted in the uterine tissue repairing followed by improvement of ovarian steroidogenesis. However, this effective function of NAC might be crucial for the restoration of arsenic-induced female reproductive organ damage in rats.

Nutritional management can assist a significant role in alleviation of arsenicosis

Consumption of arsenic contaminated water causes serious skin disease and cancer in a significant number of exposed people. Chelating agents, consider an expensive therapy, are employed in the treatment of arsenic intoxication. There are reports which suggest that the poorest suffer the most from arsenicosis. This may be due to improper diet intake, consist of low protein and micronutrients which increase the vulnerability to arsenic-related disorders. Several human studies demonstrated the associations between malnourishment and the development of arsenic-caused skin lesions, skin cancer and cardiovascular effects. Thus, there is an urgent need of implementation of mitigation strategies for improving the health of exposed populations. Nutrition enhances the detoxification process so food rich in vitamins, protein, antioxidants help in its detoxification process. Methylation is the detoxification process which takes place via S-adenosylmethionine (SAM). It is a methyl group donor and it derived its methyl group from diet. Nutritional intervention thus may appear as a practical and inexpensive approach. Nutrition provides protection from toxic effect of arsenic by two ways (i) methylation of As (ii) antioxidants which provides protection against free radical species. The governments and NGOs may run awareness programmes in arsenic affected area regarding prevention and alternate therapy which can decrease the susceptibility of the exposed population. They could also help in distributing cheaper, high protein diets particularly to the masses who cannot afford such foods. Thus, to prevent arsenicosis alternate therapy and proper nutrition could be the important strategy for alleviating its toxic effects. This mini review provides an insight on the importance of nutrition in preventing adverse effect cause by arsenic to suffer population.

Nutrients in one-carbon metabolism and urinary arsenic methylation in the National Health and Nutrition Examination Survey (NHANES) 2003-2004

Exposure to inorganic arsenic (inAs), a potent toxicant, occurs primarily through ingestion of food and water. The efficiency with which it is methylated to mono and dimethyl arsenicals (MMA and DMA) affects toxicity. Folate, vitamins B12 and B6 are required for 1C metabolism, and studies have found that higher levels of these nutrients increase methylation capacity and are associated with protection against adverse health effects from inAs, especially in undernourished populations. Our aim was to determine whether 1C-related nutrients are associated with greater inAs methylation capacity in a general population sample with overall adequate nutrition and low levels of As exposure. Univariate and multivariable regression models were used to evaluate the relationship of dietary and blood nutrients to urinary As methylation in the National Health and Nutrition Examination Survey (NHANES) 2003-2004. Outcome variables were the percent of the sum of inAs and methylated As species (inAs+MMA+DMA) excreted as inAs, MMA, and DMA, and the ratio of MMA:DMA. In univariate models, dietary folate, vitamin B6 and protein intake were associated with lower urinary inAs% and greater DMA% in adults (≥18years), with similar trends in children (6-18). In adjusted models, vitamin B6 intake (p=0.011) and RBC folate (p=0.036) were associated with lower inAs%, while dietary vitamin B12 was associated with higher inAs% (p=0.002) and lower DMA% (p=0.030). Total plasma homocysteine was associated with higher MMA% (p=0.004) and lower DMA% (p=0.003), but not with inAs%; other blood nutrients showed no association with urinary As. Although effect size is small, these findings suggest that 1C nutrients can influence inAs methylation and potentially play an indirect role in reducing toxicity in a general population sample.

Epigenetics of breast cancer: Modifying role of environmental and bioactive food compounds

SCOPE

Reduced expression of tumor suppressor genes (TSG) increases the susceptibility to breast cancer. However, only a small percentage of breast tumors is related to family history and mutational inactivation of TSG. Epigenetics refers to non-mutational events that alter gene expression. Endocrine disruptors found in foods and drinking water may disrupt epigenetically hormonal regulation and increase breast cancer risk. This review centers on the working hypothesis that agonists of the aromatic hydrocarbon receptor (AHR), bisphenol A (BPA), and arsenic compounds, induce in TSG epigenetic signatures that mirror those often seen in sporadic breast tumors. Conversely, it is hypothesized that bioactive food components that target epigenetic mechanisms protect against sporadic breast cancer induced by these disruptors.

METHODS AND RESULTS

This review highlights (i) overlaps between epigenetic signatures placed in TSG by AHR-ligands, BPA, and arsenic with epigenetic alterations associated with sporadic breast tumorigenesis; and (ii) potential opportunities for the prevention of sporadic breast cancer with food components that target the epigenetic machinery.

CONCLUSIONS

Characterizing the overlap between epigenetic signatures elicited in TSG by endocrine disruptors with those observed in sporadic breast tumors may afford new strategies for breast cancer prevention with specific bioactive food components or diet.

Arsenic metabolism and one-carbon metabolism at low-moderate arsenic exposure: Evidence from the Strong Heart Study

B-vitamins involved in one-carbon metabolism (OCM) can affect arsenic metabolism efficiency in highly arsenic exposed, undernourished populations. We evaluated whether dietary intake of OCM nutrients (including vitamins B2, B6, folate (B9), and B12) was associated with arsenic metabolism in a more nourished population exposed to lower arsenic than previously studied. Dietary intake of OCM nutrients and urine arsenic was evaluated in 405 participants from the Strong Heart Study. Arsenic exposure was measured as the sum of iAs, monomethylarsonate (MMA) and dimethylarsenate (DMA) in urine. Arsenic metabolism was measured as the individual percentages of each metabolite over their sum (iAs%, MMA%, DMA%). In adjusted models, increasing intake of vitamins B2 and B6 was associated with modest but significant decreases in iAs% and MMA% and increases in DMA%. A significant interaction was found between high folate and B6 with enhanced arsenic metabolism efficiency. Our findings suggest OCM nutrients may influence arsenic metabolism in populations with moderate arsenic exposure. Stronger and independent associations were observed with B2 and B6, vitamins previously understudied in relation to arsenic. Research is needed to evaluate whether targeting B-vitamin intake can serve as a strategy for the prevention of arsenic-related health effects at low-moderate arsenic exposure.

Folic acid enhances the apoptotic and genotoxic activity of carboplatin in HeLa cell line

In human tumor cells, experimental and clinical evidence indicates that some factors involved in signal transduction and cell growth can also modulate the response to chemotherapeutic treatment. The aim of the present study was to investigate the role of folic acid (FA) as a modulator of carboplatin (CBDCA) activity. Genotoxicity and cytotoxicity induced by CBDCA alone and in combination with FA were assessed in cultured HeLa cells. We used comet assay, mitotic index analysis, MTT and NR assays, cytokinesis-block micronucleus cytome assay and annexin V-IP as different cytotoxicity and genotoxicity approaches for human cervical carcinoma cell line studies. The results showed that addition of 900nM FA together with 40.4mM CBDCA enhanced the activity of the platinum compound, increasing its effect on cell death by nearly 20%, as evidenced by the MTT and NR assays. Moreover, not only higher levels of DNA and chromosomal damage were reached but also the number of necrotic and apoptotic cells were significantly increased when cell cultures were treated with the combined procedure. This situation opens the possibility to explore the use of FA in platinum-based chemotherapy protocols to reduce the platinum doses for patient treatment and decrease the chance of developing the known side effects without losing biological activity.

Effects of Sodium Arsenite and Arsenate in Testicular Histomorphometry and Antioxidants Enzymes Activities in Rats

The main source of environmental arsenic exposure in most countries of the world is drinking water in which inorganic forms of arsenic predominate. The present study was aimed to test the impact of two different compounds of inorganic arsenic in histomorphometric and enzymatic parameters in the testes by oral exposition. Adult Wistar male rats were exposed to sodium arsenite and arsenate in drinking water, testing for each chemical form the concentrations of 0.01 and 10 mg/L per 56 days. The animals intoxicated with arsenic, mainly sodium arsenite, showed reduction in the percentage of seminiferous epithelium and in proportion and volume of Leydig cells. Moreover, there was an increase in the percentage of tunica propria, lumen, lymphatic space, blood vessels, and macrophages. The activity of superoxide dismutase (SOD) did not change among the groups. However, the activity of catalase (CAT) decreased in animals exposed to both arsenic compounds. In addition, the higher concentration of arsenic, mainly as sodium arsenite, caused vacuolization in the seminiferous epithelium. The body and testes weight as well as testosterone concentration remained unchanged among the groups. In conclusion, exposition to arsenic, mainly as sodium arsenite, caused alteration in histomorphometric parameters and antioxidant defense system in the testes.

Hypothiocyanite produced by human and rat respiratory epithelial cells inactivates extracellular H1N2 influenza A virus

OBJECTIVE AND DESIGN

Our aim was to study whether an extracellular, oxidative antimicrobial mechanism inherent to tracheal epithelial cells is capable of inactivating influenza H1N2 virus.

MATERIAL OR SUBJECTS

Epithelial cells were isolated from tracheas of male Sprague-Dawley rats. Both primary human and rat tracheobronchial epithelial cells were differentiated in air-liquid interface cultures.

TREATMENT

A/swine/Illinois/02860/09 (swH1N2) influenza A virions were added to the apical side of airway cells for 1 h in the presence or absence of lactoperoxidase or thiocyanate.

METHODS

Characterization of rat epithelial cells (morphology, Duox expression) occurred via western blotting, PCR, hydrogen peroxide production measurement and histology. The number of viable virions was determined by plaque assays. Statistical difference of the results was analyzed by ANOVA and Tukey's test.

RESULTS

Our data show that rat tracheobronchial epithelial cells develop a differentiated, polarized monolayer with high transepithelial electrical resistance, mucin production and expression of dual oxidases. Influenza A virions are inactivated by human and rat epithelial cells via a dual oxidase-, lactoperoxidase- and thiocyanate-dependent mechanism.

CONCLUSIONS

Differentiated air-liquid interface cultures of rat tracheal epithelial cells provide a novel model to study airway epithelium-influenza interactions. The dual oxidase/lactoperoxidase/thiocyanate extracellular oxidative system producing hypothiocyanite is a fast and potent anti-influenza mechanism inactivating H1N2 viruses prior to infection of the epithelium.