Vitamin E and tannic acid improve DNA damage in rats submitted chronic ethanol administration

Purpose - Chronic ethanol consumption induces lipid peroxidation by increasing free radicals or reducing antioxidants and may increase damage to hepatic DNA. Tannins are polyphenolic metabolites present in various plants and one of their effects is antioxidant activity that reduces lipoperoxidation, as is the case for vitamin E. This paper aims to assess the role of tannic acid and vitamin E in lipid peroxidation and in DNA damage in rats receiving ethanol. Design/methodology/approach - A total of 60 Wistar rats were divided into six groups: control + ethanol (0-24hs), tannic acid + ethanol (0-24 hs), and vitamin E + ethanol (0-24 hs). The animals were sacrificed immediately (0 hour) or 24 hours after a period of four weeks of ethanol administration and the following measurements were made: plasma vitamin E and liver glutathione, thiobarbituric acid resistant substances, and a-tocopherol. The comet test was also applied to hepatocytes. Findings - Ethanol administration led to an increase in DNA damage (148.67 +/- 15.45 versus 172.63 +/- 18.94) during a period of 24 hours which was not detected in the groups receiving tannic acid or vitamin E. Steatosis was lower in the groups receiving tannic acid. Originality/value - The paper highlights that antioxidant role of vitamin E and of tannic acid in biological systems submitted to oxidative stress should be reevaluated, especially regarding the protective role of tannic acid against hepatic steatosis.

Sodium nitrite downregulates vascular NADPH oxidase and exerts antihypertensive effects in hypertension

Dietary nitrite and nitrate are important sources of nitric oxide (NO). However, the use of nitrite as an antihypertensive drug may be limited by increased oxidative stress associated with hypertension. We evaluated the antihypertensive effects of sodium nitrite given in drinking water for 4 weeks in two-kidney one-clip (21(1 C) hypertensive rats and the effects induced by nitrite on NO bioavailability and oxidative stress. We found that, even under the increased oxidative stress conditions present in 2K1C hypertension, nitrite reduced systolic blood pressure in a dose-dependent manner. Whereas treatment with nitrite did not significantly change plasma nitrite concentrations in 2K1C rats, it increased plasma nitrate levels significantly. Surprisingly, nitrite treatment exerted antioxidant effects in both hypertensive and sham-normotensive control rats. A series of in vitro experiments was carried out to show that the antioxidant effects induced by nitrite do not involve direct antioxidant effects or xanthine oxidase activity inhibition. Conversely, nitrite decreased vascular NADPH oxidase activity. Taken together, our results show for the first time that nitrite has antihypertensive effects in 2K1C hypertensive rats, which may be due to its antioxidant properties resulting from vascular NADPH oxidase activity inhibition. (C) 2011 Elsevier Inc. All rights reserved.

Antidepressant-like effects of N-acetyl-L-cysteine in rats

Oxidative stress disturbances have been reported in depressed patients and in animals submitted to stress. Recent evidence suggests that antidepressants may have antioxidant properties. However, the therapeutic potential of antioxidants as antidepressant drugs has not been systematically investigated. Therefore, this study tested the hypothesis that N-acetyl-L-cysteine (NAC), a cysteine prodrug with powerful antioxidant activity, would possess anti depressant-like properties in the forced swimming test. Male Wistar rats were subjected to 15 min of forced swimming and immediately afterward, 5, and 23 h later received intraperitoneal injections of NAC (5, 15, 50, 150, and 250 mg/kg), imipramine, 0 5 mg/kg) or vehicle. One hour later they were submitted to the 5 min test swimming session, where immobility time was recorded. Independent groups of animals received the same treatments and their exploratory activity was measured in an open arena for 5 min. NAC (at the doses of 15, 50, and 150 mg/kg) and imipramine induced a significant decrease in immobility time without changing exploratory behavior measured in an open arena. These results suggest that antioxidants such as NAC may have antidepressant effects. Behavioural Pharmacology (C) 19:747-750 2008 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Quercetin restores plasma nitrite and nitroso species levels in renovascular hypertension

Quercetin has antioxidants properties which may increase nitric oxide (NO) bioavailability. However, the effects of quercetin on NO status have been poorly studied. We evaluated whether quercetin improves the plasma levels of NO metabolites in two-kidney one-clip (2K1C) hypertensive rats and assessed its effect on endothelial function. Sham-operated and 2K1C rats were treated with quercetin (10 mg(-1) kg(-1) day(-1) by gavage) or vehicle for 3 weeks. Systolic blood pressure (SBP) was monitored weekly. Vascular responses to acetylcholine (Ach) and sodium nitroprusside (SNP) were assessed in hindquarter vascular bed. Plasma nitrate levels were assessed by Griess reagent and plasma nitrite and nitroso species (S, N-nitroso species) were assessed by ozone- based chemiluminescence. Aortic NADPH oxidase activity and superoxide production were evaluated. While quercetin had no effects in control normotensive rats (P > 0.05), it significantly reduced SBP in 2K1C rats (P < 0.05). At the end of treatment, plasma nitrate levels were similar in all experimental groups (P > 0.05). However, plasma nitrite and the nitroso species levels were significantly lower in 2K1C rats when compared with controls (P < 0.05). Quercetin treatment restored plasma nitrite and nitroso species levels to those found in the sham-vehicle group (P < 0.05). While quercetin treatment induced no significant changes in responses to SNP (P > 0.05), it restored the vascular responses to Ach. Quercetin significantly attenuated 2K1C-hypertension-induced increases in NADPH oxidase activity and vascular superoxide production (P < 0.05). These results suggest that the antihypertensive effects of quercetin were associated with increased NO formation and improved endothelial function, which probably result from its antioxidant effects.

Diabetes and Vascular Disease: Basic Concepts of Nitric Oxide Physiology, Endothelial Dysfunction, Oxidative Stress and Therapeutic Possibilities

The vascular manifestations associated with diabetes mellitus (DM) result from the dysfunction of several vascular physiology components mainly involving the endothelium, vascular smooth muscle and platelets. It is also known that hyperglycemia-induced oxidative stress plays a role in the development of this dysfunction. This review considers the basic physiology of the endothelium, especially related to the synthesis and function of nitric oxide. We also discuss the pathophysiology of vascular disease associated with DM. This includes the role of hyperglycemia in the induction of oxidative stress and the role of advanced glycation end-products. We also consider therapeutic strategies.

Insulin-like growth factor-1 protects preimplantation embryos from anti-developmental actions of menadione

Menadione is a naphthoquinone used as a vitamin K source in animal feed that can generate reactive oxygen species (ROS) and cause apoptosis. Here, we examined whether menadione reduces development of preimplantation bovine embryos in a ROS-dependent process and tested the hypothesis that actions of menadione would be reduced by insulin-like growth factor-1 (IGF-1). Menadione caused a concentration-dependent decrease in the proportion of embryos that became blastocysts. All concentrations tested (1, 2.5, and 5.0 mu M) inhibited development. Treatment with 100 ng/ml IGF-1 reduced the magnitude of the anti-developmental effects of the two lowest menadione concentrations. Menadione also caused a concentration-dependent increase in the percent of cells positive for the TUNEL reaction. The response was lower for IGF-1-treated embryos. The effects of menadione were mediated by ROS because (1) the anti-developmental effect of menadione was blocked by the antioxidants dithiothreitol and Trolox and (2) menadione caused an increase in ROS generation. Treatment with IGF-1 did not reduce ROS formation in menadione-treated embryos. In conclusion, concentrations of menadione as low as 1.0 mu M can compromise development of bovine preimplantation embryos to the blastocyst stage of development in a ROS-dependent mechanism. Anti-developmental actions of menadione can be blocked by IGF-1 through effects downstream of ROS generation.

Diabetes induces metabolic alterations in dental pulp

Diabetes can interfere in tissue nutrition and can impair dental pulp metabolism. This disease causes oxidative stress in cells and tissues. However, little is known about the antioxidant system in the dental pulp of diabetics. Thus, it would be of importance to study this system in this tissue in order to verify possible alterations indicative of oxidative stress. The aim of this study was to evaluate some parameters of antioxidant system of the dental pulp of healthy (n = 8) and diabetic rats (n = 8). Diabetes was induced by streptozotocin in rats. Six weeks after diabetes induction, a pool of the dental pulp of the 4 incisors of each rat (healthy and diabetic) was used for the determination of total protein and sialic acid concentrations and catalase and peroxidase activities. Data were compared by a Student t test (p <= 0.05). Dental pulps from both groups presented similar total protein concentrations and peroxidase activity. Dental pulps of diabetic rats exhibited significantly lower free, conjugated, and total sialic acid concentrations than those of control tissues. Catalase activity in diabetic dental pulps was significantly enhanced in comparison with that of control pulps. The result of the present study is indicative of oxidative stress in the dental pulp caused by diabetes. The increase of catalase activity and the reduction of sialic acid could be resultant of reactive oxygen species production.

The effects of lipoic acid and alpha-tocopherol supplementation on the lipid profile and insulin sensitivity of patients with type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled trial

Antioxidants probably play an important role in the etiology of type 2 diabetes (DM2). This study evaluated the effects of supplementation with lipoic acid (LA) and alpha-tocopherol on the lipid profile and insulin sensitivity of DM2 patients. A randomized, double-blind, placebo-controlled trial involving 102 DM2 patients divided into four groups to receive daily supplementation for 4 months with: 600 mg LA (n = 26); 800 mg alpha-tocopherol (n = 25); 800 mg alpha-tocopherol + 600 mg LA (n = 25); placebo (n = 26). Plasma alpha-tocopherol, lipid profile, glucose, insulin, and the HOMA index were determined before and after supplementation. Differences within and between groups were compared by ANOVA using Bonferroni correction. Student`s t-test was used to compare means of two independent variables. The vitamin E/total cholesterol ratio improved significantly in patients supplemented with vitamin E + LA and vitamin E alone (p <= 0.001). There were improvements of the lipid fractions in the groups receiving LA and vitamin E alone or in combination, and on the HOMA index in the LA group, but not significant. The results suggest that LA and vitamin E supplementation alone or in combination did not affect the lipid profile or insulin sensitivity of DM2 patients. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Diet and serum micronutrients in relation to cervical neoplasia and cancer among low-income Brazilian women

Cervical cancer is a leading cancer among women in developing countries. Infection with oncogenic human papillomavirus (HPV) types has been recognized as a necessary cause of this disease. Serum carotenoids and tocopherols have also been associated with risk for cervical neoplasia, but results from previous studies were not consistent. We evaluated the association of serum total carotene and tocopherols, and dietary intakes with the risk of newly diagnosed, histologically confirmed cervical intraepithelial neoplasia (CIN) grades 1, 2, 3 and invasive cancer in a hospital-based case-control study in Sao Paulo, Brazil. The investigation included 453 controls and 4 groups of cases (CIN1, n = 140; CIN2, n = 126; CIN3, n = 231; invasive cancer, n = 108) recruited from two major public clinics between 2003 and 2005. Increasing concentrations of serum lycopene were negatively associated with CIN1, CIN3 and cancer, with odds ratios (OR) (95% CI) for the highest compared to the lowest tertile of 0.53 (0.27-1.00, p for trend = 0.05), 0.48 (0.22-1.04, p for trend = 0.05) and 0.18 (0.06-0.52, p for trend = 0.002), respectively, after adjusting for confounding variables and HPV status. Increasing concentrations of serum alpha- and gamma-tocopherols, and higher dietary intakes of dark green and deep yellow vegetables/fruit were associated with nearly 50% decreased risk of CIN3. These results support the evidence that a healthy and balanced diet leading to provide high serum levels of antioxidants may reduce cervical neoplasia risk in low-income women.

Dietary predictors of serum total carotene in low-income women living in Sao Paulo, south-east Brazil

Objective Dietary intake and nutritional status of antioxidant vitamins have been reported to protect against some cancers The objective of the present study was to assess the correlations between serum levels of carotenoids (including beta-, alpha- and gamma-carotene), lycopene, retinol, alpha- and gamma-tocopherols, and dietary intakes estimated by an FFQ, among low-income women in the Brazilian Investigation into Nutrition and Cervical Cancer Prevention (BRINCA) study. Design Cross-sectional study of data for 918 women aged 21-65 years participating in the BRINCA study in Sao Paulo city. Multiple linear regression models were used with serum nutrient levels as the dependent variable and dietary intake levels as the independent variable, adjusted for confounding factors. Results In energy-adjusted analyses, the intakes of dark green and deep yellow vegetables and fruits (partial R(2) = 4.8%), total fruits and juices (partial R(2) = 1.8%), vegetables and fruits (partial R(2) = 1.8%), carrots (partial R(2) = 1.4%) and citrus fruits and juices only (partial R(2) = 0.8%) were positively correlated only with serum total carotene levels, after adjusting for serum total cholesterol concentration, age, hospital attended, smoking status. BMI and presence of cervical lesions Multiple-adjusted serum levels of carotenoids were positively correlated with intake quartiles of dark green and deep yellow vegetables and fruits and total fruits and juices independent of smoking status. Conclusions The intake of specific fruits and vegetables was an independent predictor of serum total carotene levels in low-income women living in Sao Paulo

Evaluation of phenolic compounds in mate (Ilex paraguariensis) processed by gamma radiation

The radiation food processing has been demonstrating great effectiveness in the attack of pathogenic agents, while little compromising nutritional value and sensorial properties of foods. The mate (Ilex paraguariensis), widely consumed product in South America, generally in the form of infusions with hot or cold water, calls of chimarrao or terere, it is cited in literature as one of the best sources phenolic compounds. The antioxidants action of these constituent has been related to the protection of the organism against the free radicals, generated in alive, currently responsible for the sprouting of some degenerative illness as cancer, arteriosclerosis, rheumatic arthritis and cardiovascular clutters among others. The objective of that work was to evaluate the action of the processing for gamma radiation in phenolic compounds of terere beverage in the doses of 0, 3, 5, 7 and 10 kGy. The observed results do not demonstrate significant alterations in phenolic compounds of terere beverage processed by gamma radiation. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

Yerba Mate (Ilex paraguariensis) Aqueous Extract Decreases Intestinal SGLT1 Gene Expression but Does Not Affect Other Biochemical Parameters in Alloxan-Diabetic Wistar Rats

Yerba mate (Ilex paraguariensis) is rich in polyphenols, especially chlorogenic acids. Evidence suggests that dietary polyphenols could play a role in glucose absorption and metabolism. The aim of this study was to evaluate the antidiabetic properties of yerba mate extract in alloxan-induced diabetic Wistar rats. Animals (n = 41) were divided in four groups: nondiabetic control (NDC, n = 10), nondiabetic yerba mate (NDY, n = 10), diabetic control (DC, n = 11), and diabetic yerba mate (NDY, n = 10). The intervention consisted in the administration of yerba mate extract in a 1 g extract/kg body weight dose for 28 days; controls received saline solution only. There were no significant differences in serum glucose, insulin, and hepatic glucose-6-phosphatase activity between the groups that ingested yerba mate extract (NDY and DY) and the controls (NDC and DC). However, the intestinal SGLT1 gene expression was significantly lower in animals that received yerba mate both in upper (p = 0.007) and middle (p < 0.001) small intestine. These results indicate that bioactive compounds present in yerba mate might be capable of interfering in glucose absorption, by decreasing SGLT1 expression.

Plasma concentrations of ascorbic acid in parturients from a hospital in Southeast Brazil

Background & aims: Pregnancy is a period characterized by high metabolic requirements and physiological changes in the female organism. During this period, Low body stores of vitamins and minerals including antioxidants can have adverse effects on the mother and foetus. This cross-sectional. study assessed plasma concentrations of ascorbic acid (AA) in 117 parturients admitted into a university hospital in S (a) over tildeo Paulo city, Brazil. Methods: The concentrations of AA were determined by the high performance liquid chromatographic method. Data concerning socioeconomic, demographic, obstetric and nutritional characteristics of the parturients were collected by a standardized questionnaire. Results: The prevalence of AA deficiency (< 22.7 mu mol/L) among the parturients was 30.8%. Mean plasma AA concentrations were lower in single/divorced women (27.84 +/- 3.48 mu mol./L) compared with married/single with partner women (34.78 +/- 1.85 mu mol/L) (p = 0.047). Blood AA concentrations were significantly correlated with per capita income (r = 0.36, p < 0.001) and vitamin C-rich food intake score (r = 0.42, p < 0.001). Conclusion: The high prevalence of hypovitaminosis C detected in this study is probably due to an inadequate intake of foods rich in vitamin C and tow income. We alert to the need for increasing the intake of vitamin C-rich foods through educational. programs, especially for tow income populations. (c) 2007 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Extracts from pitanga (Eugenia uniflora L.) leaves: Influence of extraction process on antioxidant properties and yield of phenolic compounds

Different extraction processes were employed to extract the polyphenolic compounds from pitanga (Eugenia uniflora L) leaves: a one-step process using water, ethanol or supercritical CO(2) as solvents, and a two-step process using supercritical CO(2) followed by either water or ethanol. The total polyphenolic compounds, total flavonoids and antioxidant activity were determined in all the extracts obtained. The process performance was evaluated with respect to three variables: global extraction yield, concentration and yield of both polyphenols and flavonoids in the extracts. For the one-step extraction, the results showed that the extraction yield increased with solvent polarity. For the two-step process, the results suggested that water was more efficient in extracting the phenolic compounds from E. uniflora when the matrix was previously extracted with scCO(2). With respect to the antioxidant activity, the ethanolic extracts obtained from both processes, using either the DPPH radical scavenging method or the beta-carotene bleaching method, presented high antioxidant activities. (C) 2010 Elsevier B.V. All rights reserved.

Leaf antioxidant fluctuations and growth responses in saplings of Caesalpinia echinata Lam. (brazilwood) under an urban stressing environment

We intended to establish how efficient the leaf antioxidant responses of C. echinata are against oxidative environmental conditions observed in an urban environment and their relations to growth and biomass parameters. Plants were grown for 15 months in four sites: Congonhas and Pinheiros, affected by pollutants from vehicular emissions; Ibirapuera, affected by high O(3) concentrations; and a greenhouse with filtered air. Fifteen plants were quarterly removed from each site for analysis of antioxidants, growth and biomass. Plants growing in polluted sites showed alterations in their antioxidants. They were shorter, had thicker stems and produced less leaf biomass than plants maintained under filtered air. The fluctuations in the levels of antioxidants were significantly influenced by combined effects of climatic and pollution variables. The higher were the antioxidant responses and the concentrations of pollutant markers of air contamination in each site the slower were the growth and biomass production. (C) 2009 Elsevier Inc. All rights reserved.