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The Brazil nut (Bertholletia excelsa, H.B.K.) originating from the Amazon region is one of the richest known sources of selenium (Se), a micronutrient that is essential and required for optimal physiological functioning. This mineral presents several health benefits, including improvement of the redox cellular status and maintenance of genomic stability. Knowing that type 2 diabetes mellitus (T2D) is strongly linked to oxidative stress and consequently DNA damage, the aim of this study was to assess the ex vivo antioxidative effects of Se through Brazil nut consumption and its potential in preventing oxidative DNA damage induced by H2O2. In order to accomplish this, the Comet assay (single-cell gel electrophoresis) was used to measure DNA damage in peripheral blood cells harvested before and after supplementation with Brazil nut. Comet assay was also applied ex vivo to measure the potential of Se to prevent oxidative damage to DNA induced by H2O2 in blood of type 2 diabetes patients collected before and after six months of supplementation with Brazil nut. We found that supplementation with Brazil nuts significantly increased serum Se levels. Furthermore, we observed a significant increase in fasting blood glucose after six months of consuming Brazil nuts; however, no significant effect was observed on the levels of glycated hemoglobin. Finally, we noticed that the cells were more resistant to H2O2-induced DNA damage after six months of supplementation with Brazil nut. Thus, consumption of Brazil nuts could decrease oxidative DNA damage in T2D patients, probably through the antioxidative effects of Se. [ABSTRACT FROM AUTHOR]

Melanoma, an aggressive skin cancer originating from melanocytes, can metastasize to the lungs, liver, cortex, femur, and spinal cord, ultimately resulting in DNA mutagenic effects. Melatonin is an endogenous hormone and free radical scavenger that possesses the ability to protect the DNA and to exert anti-proliferative effects in melanoma cells. The aim of this study was to evaluate the effects of B16F10 melanoma cells and the effects of melatonin supplementation on genotoxic parameters in murine melanoma models. Thirty-two male C57Bl/6 mice were divided in the following four groups: PBS + vehicle (n = 6), melanoma + vehicle (n = 10), PBS + melatonin (n = 6), and melanoma + melatonin (n = 10). The melanoma groups received a B16F10 cell injection, and melatonin was administered during 60 days. After treatment, tumor sizes were evaluated. DNA damage within the peripheral blood, lungs, liver, cortex, and spinal cord was determined using comet assay, and the mutagenicity within the bone marrow was determined using the micronucleus test. B16F10 cells effectively induced DNA damage in all tissues, and melatonin supplementation decreased DNA damage in the blood, liver, cortex, and spinal cord. This hormone exerts anti-tumor activity via its anti-proliferative, antioxidative, and pro-apoptotic effects. As this result was not observed within the lungs, we hypothesized that melatonin can induce apoptosis in cancer cells, and this was not evaluated by comet assay. This study provides evidence that melatonin can reduce the genotoxicity and mutagenicity caused by B16F10 cells. [ABSTRACT FROM AUTHOR]

The consumption of fructose during pregnancy can cause hyperglycaemia and may stimulate production of reactive oxygen species; however, there are only a few studies reporting whether fructose consumption during pregnancy causes DNA damage. Therefore, the aim of this study was to evaluate the effects of fructose consumption on genetic and biochemical parameters in Swiss mice treated during pregnancy and lactation. For this, 15 couples of 60-day-old Swiss mice were divided into three groups of five couples: negative control (water) and two fructose groups (fructose dose of 10%/l and 20%/l). During this period, we evaluated food consumption, energy efficiency and body weight. Samples of blood were collected from the females before copulation, after the 15th day of conception and on the 21st day after the lactation period, for the glycaemic and lipid profiles as well as comet assay and micronucleus (MN) test. Comet assay and MN test evaluate DNA damage and clastogenicity, respectively. In the gestation and lactation period, the two fructose doses tested showed DNA damage as observed in the comet assay, which is associated with an increase in dietary intake, body weight, lipid profile and fasting glycaemia in females. Thus, it can be suggested that the high consumption of fructose during these periods is harmful for pregnancy and lactation. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the genotoxic effect of lettuce (Lactuca sativa L.), beet (Beta vulgaris L.), broccoli (Brassica oleracea var. italica), and kale (Brassica oleracea var. acephala) grown in vegetable garden built on the deposits of coal tailings. For this, we used 72 healthy male Swiss albino mice that received juice from the vegetables in an acute or chronic treatment. Using comet assay, we determined that acute administration of the juices of all vegetables from the coal-mining area was genotoxic, and increased the DNA damage in the blood, liver, and cerebral cortex of mice. Therefore, the present data suggest that intake of vegetables cultivated over coal waste results in an increase in DNA damage in some organs; this situation may pose a risk to health. [ABSTRACT FROM AUTHOR]

ObjectiveThis study investigated the influence of ageing – in particular the decrease of gonadal hormone levels during the ageing process – on the memory and the levels of DNA damage in the hippocampus of female rats.MethodsThree groups of female Wistar rats were investigated: Group I consisted of non-ovariectomised, adult animals (6 months old); Group II consisted of non-ovariectomised, aged animals (18 months old); and Group III consisted of ovariectomised, aged animals (18 months old). The memory of the animals in these groups was examined via novel object recognition and inhibitory avoidance tests. The hippocampus tissue samples of all animals were obtained via biopsy and used to quantify the DNA damage using a Comet Assay.ResultsAccording to our findings, the process of ageing results in a change during the behavioural tests. To prevent genotoxic damage to the hippocampus caused by the ageing process, lowered hormone levels seem to be part of a protective biochemical mechanism in the body of rats. Animals that were previously submitted to an ovariectomy adapted better to these lower levels of hormones.ConclusionOur results indicate that ovariectomy can provide beneficial long-term effects on the memory. However, this could be specific to the kind of memory examined, as the aversive memory deficits caused by ageing were not affected by ovariectomy. [ABSTRACT FROM PUBLISHER]

Highlights: [•] Patients suffering from HIV/AIDS are commonly treated with nevirapine and efavirenz. [•] Acute and subchronic use of antiretroviral drugs causes various adverse effects. [•] We investigated acute and subchronic effects of efavirenz and nevirapine on DNA damage. [•] Acute or subchronic administration of nevirapine did not increase the DNA damage in mice. [•] Subchronic treatment with efavirenz increased the observed DNA damage in the brain of mice. [ABSTRACT FROM AUTHOR]

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Highlights: [•] We assess heavy metal content and genotoxicity in frogs from a coal area. [•] Contents of heavy metal in frogs from coal area were higher than reference values. [•] We detected the highest contents of heavy metal in the liver and in the kidneys. [•] The genotoxicity was significantly higher in specimens from the coal area. [Copyright &y& Elsevier]

Abstract: We assessed the content of heavy metals in the liver and the DNA damage in blood cells of insectivore bats in the Catarinense Carboniferous Basin, Southern Brazil. Three bats species (Molossus molossus, Tadarida brasiliensis and Eptesicus diminutus) were collected in a coal mining area and in a control area. The heavy metal content in bats was detected according to the PIXE technique and the DNA damage was assessed by the Comet assay. The contents of Cr, Ni, Cu and Pb in M. molossus and of Cu and Fe in T. brasiliensis from the coal mining area was higher than in the animals from the control area. In both areas differences in metal contents in the liver were observed between the bat species. The parameters assessed by the Comet assay were significantly higher in E. diminutus as compared to M. molossus and T. brasiliensis. Values of both Comet assay parameters were significantly higher in the mining area as compared to the control area only for T. brasiliensis. [Copyright &y& Elsevier]

Tityus serrulatus is the scorpion associated with the most severe cases of scorpion envenoming in Brazil. However, there are no studies reporting the genotoxic effects of this venom in natural or experimental envenomations. It is well known that DNA-damage responses are providing opportunities for improving disease detection and management. In this study was evaluating the genotoxicity of the T. serrulatus venom in different organs (hippocampus, cortex, striatum, blood, heart, lung, liver and kidney) and periods in mice experimentally envenomed. ELISA and the Comet assays were used to quantification of venoms antigens and DNA damage, respectively. Forty-eight Swiss mice were divided into five groups and 0.5 DL 50 of T. serrulatus venom (0.90 mg/kg) was administered intraperitoneally in each animal. Euthanasia was performed by cervical dislocation in the period of 0h (control group) 1h, 2h, 6h and 12h, where it the tissues were removed. The results showed high DNA damage in all structures analyzed, suggesting that T. serrulatus venom presented genotoxic activity or some secondary effect generated by venom injection. In the ELISA test, toxic circulant antigens were verified in practically all organs at the time intervals analyzed. Therefore, the distribution of the venom changes from organ to organ. We conclude that scorpion envenoming affects DNA in all organs analyzed even when the venom concentration is lower or no detectable, DNA damage persists. [ABSTRACT FROM AUTHOR]

Acerola contains high levels of vitamin C and rutin and shows the corresponding antioxidant properties. Oxidative stress on the other hand is an important factor in the development of obesity. In this study, we investigated the biochemical and antigenotoxic effects of acerola juice in different stages of maturity (unripe, ripe and industrial) and its main pharmacologically active components vitamin C and rutin, when given as food supplements to obese mice. Initial HPLC analyses confirmed that all types of acerola juice contained high levels of vitamin C and rutin. DPPH tests quantified the antioxidant properties of these juices and revealed higher antioxidant potentials compared to pure vitamin C and rutin. In an animal test series, groups of male mice were fed on a standard (STA) or a cafeteria (CAF) diet for 13 weeks. The latter consisted of a variety of supermarket products, rich in sugar and fat. This CAF diet increased the feed efficiency, but also induced glucose intolerance and DNA damage, which was established by comet assays and micronucleus tests. Subsequently, CAF mice were given additional diet supplements (acerola juice, vitamin C or rutin) for one month and the effects on bone marrow, peripheral blood, liver, kidney, and brain were examined. The results indicated that food supplementation with ripe or industrial acerola juice led to a partial reversal of the diet-induced DNA damage in the blood, kidney, liver and bone marrow. For unripe acerola juice food supplementation, beneficial effects were observed in blood, kidney and bone marrow. Food supplementation with vitamin C led to decreased DNA damage in kidney and liver, whereas rutin supplementation led to decreased DNA damage in all tissue samples observed. These results suggest that acerola juice helps to reduce oxidative stress and may decrease genotoxicity under obesogenic conditions. [ABSTRACT FROM AUTHOR]

The use of gold nanoparticles is increasing in medicine; however, their toxic effects remain to be elucidated. Studies show that gold nanoparticles can cross the blood–brain barrier, as well as accumulate in the brain. Therefore, this study was undertaken to better understand the effects of gold nanoparticles on rat brains. DNA damage parameters were evaluated in the cerebral cortex of adult rats submitted to acute and chronic administration of gold nanoparticles of two different diameters: 10 and 30 nm. During acute administration, adult rats received a single intraperitoneal injection of either gold nanoparticles or saline solution. During chronic administration, adult rats received a daily single injection for 28 days of the same gold nanoparticles or saline solution. Twenty-four hours after either single (acute) or last injection (chronic), the rats were euthanized by decapitation, their brains removed, and the cerebral cortices isolated for evaluation of DNA damage parameters. Our study showed that acute administration of gold nanoparticles in adult rats presented higher levels of damage frequency and damage index in their DNA compared to the control group. It was also observed that gold nanoparticles of 30 nm presented higher levels of damage frequency and damage index in the DNA compared to the 10 nm ones. When comparing the effects of chronic administration of gold nanoparticles of 10 and 30 nm, we observed that occurred significant different index and frequency damage, comparing with control group. However, there is no difference between the 10 and 30 nm groups in the levels of DNA damage for both parameters of the Comet assay. Results suggest that gold nanoparticles for both sizes cause DNA damage for chronic as well as acute treatments, although a higher damage was observed for the chronic one. [ABSTRACT FROM AUTHOR]