Brazil nut consumption reduces DNA damage in overweight type 2 diabetes mellitus patients.

Type 2 diabetes mellitus (T2D) is a metabolic disease, which occurs largely due to unhealthy lifestyle. As oxidative stress is believed to promote T2D, by inducing damage to lipids, proteins, and DNA, appropriate dietary interventions seem critical to prevent, manage, and even reverse this condition. Brazil nuts (Bertholletia excelsa, H.B.K.) are nature's richest source of selenium, a mineral that has shown several health benefits. Therefore, this study aims to assess the effects of selenium consumption, through Brazil nuts, on biochemical and oxidative stress parameters, and genomic instability in T2D patients. We recruited 133 patients with T2D, registered in the Integrated Clinics of the University of Southern Santa Catarina (Brazil). Participants consumed one Brazil nut a day for six months. Blood samples and exfoliated buccal cells were collected at the beginning and the end of the intervention. The glycemic profile, lipid profile, renal profile and hepatic profile, DNA damage and selenium content were evaluated. A total of 74 participants completed the intervention. Brazil nut consumption increased selenium and GSH levels, GPx, and CAT activity while DCF and nitrites levels decreased. Total thiols increased, and protein carbonyl and MDA levels decreased. Levels of baseline and oxidative DNA damage in T2D patients were significantly decreased, as well as the frequency of micronuclei and nuclear buds. The fasting glucose levels, HDL and LDL cholesterol, and GGT levels that increased significantly in patients with type 2 diabetes were significantly reduced with nut consumption. Our results show an increase in antioxidant activity, along with reductions of protein and lipid oxidation as well as DNA damage, suggesting that Brazil nut consumption could be an ally in reducing oxidative stress and modulating the genomic instability in T2D patients.

Effects of Ethanolic Extract of Cynara cardunculus (Artichoke) Leaves on Neuroinflammatory and Neurochemical Parameters in a Diet-Induced Mice Obesity Model.

This study aimed to evaluate the effect of Cynara cardunculus leaf ethanol extract on inflammatory and oxidative stress parameters in the hypothalamus, prefrontal cortex, hippocampus, striatum, cerebral cortex and liver of high-fat diet-induced obese mice. Food intake, body weight, visceral fat weight, and liver weight were also evaluated. Male Swiss mice were divided into control (low-fat purified diet) and obese (high-fat purified diet) groups. After 6 weeks, mice were divided into control + saline, control + C. cardunculus leaf ethanol extract, obese + saline, obese + C. cardunculus leaf ethanol extract. Cynara cardunculus leaf ethanol extract (1600 mg/kg/day) or saline was administered orally for 4 weeks. Brain structures (hypothalamus, hippocampus, prefrontal cortex, striatum and cerebral cortex) and liver were removed. Treatment with C. cardunculus leaf ethanol extract did not affect body weight but did reduce visceral fat. Obesity can cause inflammation and oxidative stress and increase the activity of antioxidant enzymes in brain structures. Treatment with ethanolic extract of C. cardunculus leaves partially reversed the changes in inflammatory damage parameters and oxidative damage parameters and attenuated changes in the antioxidant defense. The C. cardunculus leaf ethanol extract benefited from the brains of obese animals by partially reversing the changes caused by the consumption of a high-fat diet and the consequent obesity. These results corroborate those of studies indicating that the C. cardunculus leaf ethanol extract can contribute to the treatment of obesity.

Anti-genotoxic and anti-mutagenic effects of melatonin supplementation in a mouse model of melanoma.

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.

Brazil nut prevents oxidative DNA damage in type 2 diabetes patients.

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.

Melatonin supplementation over different time periods until ageing modulates genotoxic parameters in mice.

The ageing process is a multifactorial phenomenon, associated with decreased physiological and cellular functions and an increased propensity for various degenerative diseases. Studies on melatonin (N-acetyl-5-methoxytryptamine), a potent antioxidant, are gaining attention since melatonin production declines with advancing age. Hence, the aim of this study was to evaluate the effects of chronic melatonin consumption on genotoxic and mutagenic parameters of old Swiss mice. Herein, 3-month-old Swiss albino male mice (n = 240) were divided into eight groups and subdivided into two experiments: first (three groups): natural ageing experiment; second (five groups): animals that started water or melatonin supplementation at different ages (3, 6, 12 and 18 months) until 21 months. After 21 months, the animals from the second experiment were euthanized to perform the comet assay, micronucleus test and western blot analysis. The results demonstrated that melatonin prolonged the life span of the animals. Relative to genomic instability, melatonin was effective in reducing DNA damage caused by ageing, presenting antigenotoxic and antimutagenic activities, independently of initiation age. The group receiving melatonin for 18 months had high levels of APE1 and OGG1 repair enzymes. Conclusively, melatonin presents an efficient antioxidant mechanism aiding modulating genetic and physiological alterations due to ageing.

Melatonin ameliorates oxidative stress and DNA damage of rats subjected to a chemically induced chronic model of Maple Syrup Urine Disease.

Maple Syrup Urine Disease (MSUD) is an inborn error of metabolism caused by a deficiency of branched α-ketoacid dehydrogenase complex (BCKDC) activity. Branched-chain amino acids (BCAA) accumulation is, at least in part, responsible for neurological disturbances characteristic of this metabolic disorder. Experimental studies demonstrated that high levels of BCAA induce brain oxidative stress. Considering that many antioxidants are obtained from the diet, the dietary restriction in MSUD patients probably produce deficiency of vitamins and micronutrients involved in antioxidant defenses. Supplementation with synthetic melatonin has been used to prevention and treatment of pathological conditions, including brain diseases. In this study, we aimed at investigating the potential neuroprotective effect of melatonin treatment in a MSUD experimental model. Infant rats (7 day old) received twice daily subcutaneous injections of a BCAA pool (0.21472 g/kg, 190 mmol/L leucine, 59 mmol/L isoleucine and 69 mmol/L valine in saline solution (15.8 µL/g per weight/injection) or saline alone, and supplemented with melatonin (10 mg/kg, intraperitoneal) for 21 days. Oxidative stress parameters, i.e. antioxidant enzyme activity, reactive species production and damage to lipids and proteins, were assessed in the cerebral cortex, hippocampus and striatum at twenty-eight days of age. In addition, the damage to blood cell DNA was evaluated. The chronic administration of BCAA pool in infant rats induced significant oxidative stress (p < 0.05) - such as oxidation of lipids and proteins, imbalance in antioxidant enzymes activities - damages in DNA (p < 0.05) and in brain structures (cerebral cortex, hippocampus and striatum). Notably, melatonin supplementation was able to ameliorate the oxidative (p < 0.05) and antioxidant (p < 0.05) parameters in the brain and blood of the rat model of MSUD. Our results show that melatonin could be a promising therapeutic agent for MSUD.

Evaluation of genotoxicity and coumarin production in conventional and organic cultivation systems of Mikania glomerata Spreng.

Mikania glomerata Sprengel, popularly known as "guaco," is used in Brazilian folk medicine for several inflammatory and allergic conditions. Besides, the popular use "guaco" is indicated by the Brazilian Ministry of Health as a safe and effective herbal medicine. The biological activity of M. glomerata extracts is due to the presence of the coumarins, a large family of phenolic substances found in plants and is made of fused benzene and α-pyrone rings. Considering that there are few data on the biological effects of the extracts of M. glomerata, mainly in genetic level, this work aims to evaluate, in vitro, the genotoxicity and coumarin production in M. glomerata in conventional and organic growing. The data showed that the organic culture system showed double the concentration of coumarin being significantly more productive than the conventional system. Besides, the results of comet assay suggest that extracts of M. glomerata cultivated in a conventional system was genotoxic, increased DNA damage levels while the organic extracts seem to have antigenotoxic effect possibly due to the concentration of coumarins. Additional biochemical investigations are necessary to elucidate the mechanisms of action of M. glomerata extracts, which were found to have a role in protection against DNA damage.

Antinociceptive activity of Copaifera officinalis Jacq. L oil and kaurenoic acid in mice.

Copaifera officinalis L. possesses traditional uses as an analgesic, anti-inflammatory, and antiseptic. However, until now the antinociceptive effect and the mechanism of action were not described for Copaifera officinalis L. oil and no compound present in this oil was identified to be responsible for its biological effects. The goal of this study was to identify the presence of kaurenoic acid in Copaifera officinalis oil and investigate its antinociceptive effect, mechanism of action, and possible adverse effects in mice. The quantification of kaurenoic acid in Copaifera officinalis oil was done by HPLC-DAD technique. Male and female albino Swiss mice (25-35 g) were used to test the antinociceptive effect of Copaifera officinalis (10 mg/kg, intragastric) or kaurenoic acid (1 mg/kg) in the tail-flick test, intraplantar injection of capsaicin, allyl isothiocyanate (AITC) or complete Freund's adjuvant (CFA). Copaifera officinalis oil and kaurenoic acid caused the antinociceptive effect in the tail-flick test in a dose-dependent manner, and their effect was reversed by naloxone (an opioid antagonist). Copaifera officinalis oil or kaurenoic acid reduced the nociception caused by capsaicin or AITC and produced an anti-allodynic effect in the CFA model (after acute or repeated administration for 7 days). Possible adverse effects were also observed, and non-detectable adverse effect was observed for the intragastric administration of Copaiba officinalis oil or kaurenoic acid and in the same way, the treatments were neither genotoxic nor mutagenic at the doses tested. Thus, Copaiba officinalis oil, and kaurenoic acid possess antinociceptive action without adverse effects.

Vitamin D3 as adjuvant in the treatment of type 2 diabetes mellitus: modulation of genomic and biochemical instability.

Type 2 diabetes mellitus has undergone a worldwide growth in incidence in the world and has now acquired epidemic status. There is a strong link between type 2 diabetes and vitamin D deficiency. Because vitamin D has beneficial effects on glucose homeostasis, the aim of this study was to evaluate the influence of vitamin D3 supplementation on the modulation of glycaemic control and other metabolic effects, as well as modulation of genomic instability in patients with type 2 diabetes. We evaluated 75 patients with type 2 diabetes, registered in the Integrated Clinics of the University of Southern Santa Catarina. Participants received 4000 IU of vitamin D3 (25(OH)D) supplementation daily for 8 weeks. Blood samples were collected at the beginning and at the end of the supplementation, and 4 weeks after the end of supplementation. The glycidic and lipid profiles [total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein and triglycerides], oxidative stress, DNA damage and 25(OH)D levels were evaluated. Vitamin D3 supplementation for 8 weeks showed enough to significantly increase blood levels of 25(OH)D. A significant difference in lipid profile was observed only in non-HDL cholesterol. Significant changes were observed in glucose homeostasis (fasting glucose and serum insulin) and, in addition, a reduction in the parameters of oxidative stress and DNA damage. There was a significant reduction in the values of 25(OH)D 4 weeks after the end of the supplementation, but levels still remained above baseline. Use of vitamin D supplementation can be an ally in the health modulation of patients with type 2 diabetes mellitus.

Hibiscus acetosella extract protects against alkylating agent-induced DNA damage in mice.

Hibiscus acetosella was shown to exert beneficial effects in humans and animal models however, the effects of this plant on DNA are unknown. The aim of this study was to determine the antigenotoxic and antimutagenic effects of H. acetosella extracts on alkylating agent methyl methanesulfonate (MMS) in vivo in mice. Initially, we performed analysis of phenolic compounds in extracts of H. acetosella by high-performance liquid chromatography (HPLC). Next, mice were divided into 8 groups and treated with distilled water or plant extract (0.1 ml/10 g) by gavage for 15 days, followed by intraperitoneal (ip) administration of saline solution or MMS (40 mg/Kg b.w) on day 16. Caffeic acid, following by gallic acid, gallocatechin, coumaric acid, and 3,4-dihydroxybenzoic acid were found to be present in extracts of H. acetosella leaves. In peripheral blood analysis of groups receiving pretreatment with H. acetosella at doses of 50 or 100 mg/kg plus MMS decreased DNA damage as evidenced by comet assay and Micronucleus assays relative to MMS alone. These results suggested that H. acetosella extracts exerted protective effects dose dependent against genotoxicity and mutagenicity induced by alkylating agents.

Modulatory effects of taurine on metabolic and oxidative stress parameters in a mice model of muscle overuse.

OBJECTIVE: The aim of this study was to investigate the regulatory effects of taurine on the biochemical parameters of muscle injury by overuse. METHODS: Male Swiss mice were divided into four groups: control (Ctrl), overuse (Ov), taurine (Tau), and overuse plus taurine (OvTau). High-intensity exercise sessions were administered for 21 d with concomitant subcutaneous injections of taurine (150 mg/kg). The mice were then sacrificed. The quadriceps muscles were surgically removed for subsequent histologic analysis and evaluation of mitochondrial function, oxidative stress parameters, tissue repair, and DNA damage markers. RESULTS: The Ov group showed significant differences compared with the Ctrl group (all P <0.05). The fiber area decreased by 49.34%, whereas the centralized nuclei contents (Ctrl = 1.33%; Ov = 28.67%), membrane potential (Ctrlsuc = 179.05 arbitrary fluorescence units (AFUs), Ctrlsuc+ADP = 198.11 AFUs; Ovsuc = 482.95 AFUs, Ovsuc+ADP = 461.6 AFUs), complex I activity (Ctrl = 20.45 nmol ⋅ min ⋅ mg protein, Ov = 45.25 nmol ⋅ min ⋅ mg protein), hydrogen peroxide (Ctrlsuc = 1.08 relative fluorescence unit (RFU) ⋅ sec ⋅ mg protein, Ctrlsuc+ADP = 0.23 RFU ⋅ sec ⋅ mg protein; Ovsuc = 5.02 RFU ⋅ sec ⋅ mg protein, Ovsuc+ADP = 0.26 RFU ⋅ sec ⋅ mg protein) and malondialdehyde (Ctrl = 0.03 nmol ⋅ mg ⋅ protein, Ov = 0.06 nmol ⋅ mg ⋅ protein) levels, and DNA damage (Ctrlfreq = 7.17%, Ovfreq = 31.17%; Ctrlindex = 4.17, Ovindex = 72.5) were increased. Taurine administration reduced the number of centralized nuclei (OvTau = 5%), hydrogen peroxide levels (OvTausuc = 2.81 RFU ⋅ sec ⋅ mg protein, OvTaussuc+ADP = 1.54 RFU ⋅ sec ⋅ mg protein), membrane potential (OvTausuc = 220.18 AFUs, OvTaussuc+ADP = 235.28 AFUs), lipid peroxidation (OvTau = 0.02 nmol/mg protein), and DNA damage (OvTaufreq = 21.33%, OvTauindex = 47.83) and increased the fiber area by 54% (all P <0.05). CONCLUSION: Taken together, these data suggest that taurine supplementation modulates various cellular remodeling parameters after overuse-induced muscle damage, and that these positive effects may be related to its antioxidant capacity.

Role of antioxidant treatment on DNA and lipid damage in the brain of rats subjected to a chemically induced chronic model of tyrosinemia type II.

Tyrosine levels are abnormally elevated in tissues and body fluids of patients with inborn errors of tyrosine metabolism. Tyrosinemia type II, which is caused by tyrosine aminotransferase deficiency, provokes eyes, skin, and central nervous system disturbances in affected patients. However, the mechanisms of brain damage are still poorly known. Considering that studies have demonstrated that oxidative stress may contribute, along with other mechanisms, to the neurological dysfunction characteristic of hypertyrosinemia, in the present study we investigated the effects of antioxidant treatment (NAC and DFX) on DNA damage and oxidative stress markers induced by chronic administration of L-tyrosine in cerebral cortex, hippocampus, and striatum of rats. The results showed elevated levels of DNA migration, and thus DNA damage, after chronic administration of L-tyrosine in all the analyzed brain areas, and that the antioxidant treatment was able to prevent DNA damage in cerebral cortex and hippocampus. However, the co-administration of NAC plus DFX did not prevent the DNA damage in the striatum. Moreover, we found a significant increase in thiobarbituric acid-reactive substances (TBA-RS) and DCFH oxidation in cerebral cortex, as well as an increase in nitrate/nitrite levels in the hippocampus and striatum. Additionally, the antioxidant treatment was able to prevent the increase in TBA-RS levels and in nitrate/nitrite levels, but not the DCFH oxidation. In conclusion, our findings suggest that reactive oxygen and nitrogen species and oxidative stress can play a role in DNA damage in this disorder. Moreover, NAC/DFX supplementation to tyrosinemia type II patients may represent a new therapeutic approach and a possible adjuvant to the current treatment of this disease.

Omega-3 fatty acid supplementation decreases DNA damage in brain of rats subjected to a chemically induced chronic model of Tyrosinemia type II.

Tyrosinemia type II is an inborn error of metabolism caused by a mutation in a gene encoding the enzyme tyrosine aminotransferase leading to an accumulation of tyrosine in the body, and is associated with neurologic and development difficulties in numerous patients. Because the accumulation of tyrosine promotes oxidative stress and DNA damage, the main aim of this study was to investigate the possible antioxidant and neuroprotective effects of omega-3 treatment in a chemically-induced model of Tyrosinemia type II in hippocampus, striatum and cerebral cortex of rats. Our results showed chronic administration of L-tyrosine increased the frequency and the index of DNA damage, as well as the 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in the hippocampus, striatum and cerebral cortex. Moreover, omega-3 fatty acid treatment totally prevented increased DNA damage in the striatum and hippocampus, and partially prevented in the cerebral cortex, whereas the increase in 8-OHdG levels was totally prevented by omega-3 fatty acid treatment in hippocampus, striatum and cerebral cortex. In conclusion, the present study demonstrated that the main accumulating metabolite in Tyrosinemia type II induce DNA damage in hippocampus, striatum and cerebral cortex, possibly mediated by free radical production, and the supplementation with omega-3 fatty acids was able to prevent this damage, suggesting that could be involved in the prevention of oxidative damage to DNA in this disease. Thus, omega-3 fatty acids supplementation to Tyrosinemia type II patients may represent a new therapeutic approach and a possible adjuvant to the curren t treatment of this disease.

Corrective effects of acerola (Malpighia emarginata DC.) juice intake on biochemical and genotoxical parameters in mice fed on a high-fat diet.

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.