Olimpia Carreras

Protective effect of folic acid against oxidative stress produced in 21-day postpartum rats by maternal-ethanol chronic consumption during pregnancy and lactation period.

In this paper we show the protective effect of folic acid on oxidative stress in offspring caused by chronic maternal ethanol consumption during pregnancy and the lactation period. Glutathione reductase (GR) specific activity was assayed in liver and pancreas of offspring and mothers. In the offspring, these tissues were also assayed for markers of oxidative damage to lipids and proteins. The results show that ethanol exposure during pregnancy and lactation increased the specific activity of GR in tissues of the mothers (32–34% increase) as well as in the liver of their progeny (24%). Thiobarbituric acid reactive substances (TBARS) were also increased in the liver and pancreas of 21-day-old rats (37- and 54%, respectively). Alcohol also increased the amount of carbonyl groups in proteins in both tissues. These measures of ethanol-mediated oxidative stress were mitigated when pregnant rats were treated with folic acid concomitantly to ethanol administration. The antioxidant capacity of folic acid seems to be involved in its protective effect. The results obtained in the present work suggest that folic acid may be useful in the prevention of damage and promotion of health of the progeny of ethanol-treated rats.

Lipid Metabolism in Ethanol-Treated Rat Pups and Adults: Effects of Folic Acid

AIMS In this study we determined whether a folic acid-supplemented diet could change hyperlipaemia provoked by chronic ethanol intake in adult and pup rats. METHODS Animals were randomized into eight groups (four adults and four pups): control groups, water and basic diet; alcohol groups, 20% ethanol and basic diet; alcohol folic acid groups, 20% ethanol and diet supplemented with folic acid; control folic acid groups, water and folic acid-supplemented diet. We determined serum and liver total cholesterol (Chol), HDL, triglycerides (TG), phospholipids (PL) and bile acids (BA) levels in all of the groups. Hydroxymethylglutaryl-CoA (HMG-CoA) reductase activity was also measured in the livers. RESULTS Ethanol-fed rats have higher serum HDL and PL levels in pups and higher serum LDL, TG and PL levels in adults than controls and supplemented animals with or without alcohol ingestion. Ethanol provokes an increase in hepatic Chol and BA, and a decrease in hepatic TG and PL in pups; in adults it also provokes an increase in hepatic Chol and BA and a significant increase in HMG-CoA reductase activity. Alcohol intake plus folic acid supplementation has no effects on these values except BA levels that were significantly higher, in both pups and adult rats, than in the control group. CONCLUSION Despite the fact that alcohol intake provokes different lipid alterations in adults and in pups whose mothers drank ethanol, folic acid contributes to the alleviation of these adverse effects reducing HMG-CoA reductase activity in adult rats and, except BA levels, to normalizing lipids values due to the fact that folic acid acts as a choleretic compound. We can therefore assume that folic acid supplementation reduces alcohol-induced hypercholesterolaemia by decreasing synthesis and increasing catabolism.

Folic acid intestinal absorption in newborn rats at 21 day postpartum: effects of maternal ethanol consumption.

This study was designed to examine the effects of prenatal and postnatal exposure of ethanol in the in vivo absorption of free folic acid in the small intestine in pups rats at the 21st day after birth. The rats were accustomed to increasing amounts of ethanol (5 to 20%, vol/vol) in tap water for 1 month. During pregnancy and suckling period, ethanol-fed dams were assigned again to ethanol 20% in drinking water. Two sets of experiments were performed. In the first set, jejunal free folic acid absorption in control group and litters nursed by dams receiving ethanol showed a gradual increase along with the increase of perfusion time at all the assayed concentrations. In general, in litters of ethanol-fed dams, jejunal free folic acid absorption expressed as nmol/intestinal surface, nmol/g tissue wet weight and nmol/g tissue dry weight were higher than in control animals. In the second set of experiments, in distal ileum loops, free folic acid absorption did not occur in control pups, but appeared in litters exposed to ethanol. Milk folic acid levels are significantly decreased in ethanol-treated dams. However, only a slight decrease in the serum folic acid levels occurs in litters of ethanol-fed dams. In conclusion, the results obtained in the present work suggested a different pattern of free folic acid absorption in distal ileum for the two groups. The exposure of rats to ethanol during the pregnancy and suckling period, can affect postnatal development of intestinal functions and could play a role in the genesis of malnutrition observed in the infant.

Dietary selenium plus folic acid as an antioxidant therapy for ethanol-exposed pups.

BACKGROUND Nutrients such as folic acid and selenium are decreased in dams exposed to ethanol during gestation and lactation, affecting their metabolism, antioxidant balance, and the future health of their progeny. We will study whether the supplementation of the maternal diet with folate and selenium can prevent ethanol-induced oxidative liver disorders in the offspring. METHODS Dams were randomised into four groups: control, alcohol, alcohol+folic acid+Se, and control+folic acid+Se. We determined selenium by graphite-furnace atomic absorption and antioxidant enzyme activities, lipid peroxidation, and protein carbonyl by spectrophotometry in the offspring. RESULTS Alcohol increased serum Se levels and glutathione peroxidase (GPx) activity. However, in the liver of pups from ethanol-exposed dams a decrease in selenium was provoked and GPx activity increased with the double supplementation. Glutathione reductase (GR) and catalase (CAT) activities increased with ethanol, while double supplementation significantly decreased the GR activity. The supplemented diet reduced the protein peroxidation found in ethanol pups. CONCLUSIONS These results suggest that folic acid+Se could be effective in neutralising the damage of ethanol consumption in pups since it prevents peroxidation protein products.

Alcohol, Gestation and Breastfeeding: Selenium as an Antioxidant Therapy

AIM The aim of this paper is to study the relationship between alcohol, selenium and oxidative stress in breastfeeding rat pups exposed to ethanol during gestation and lactation. We have also studied how a Se-supplemented diet among mothers could prevent different oxidative liver disorders in the pups. METHOD Pups of 21 days were randomized into four groups: control group (C), alcohol group (A), alcohol selenium group (AS) and control selenium group (CS). Alcohol was supplied to their mothers for 13 weeks (induction, reproduction, gestation and lactation periods). The selenium-supplemented diet contained 0.5 ppm as selenite. We determined serum and liver selenium by graphite-furnace atomic absorption spectrometry. We measured antioxidant enzyme activities: glutathione peroxidase (GPx), glutathione reductase (GR), catalase (CAT) and superoxide dismutase (SOD); and lipid peroxidation (TBARS) and protein carbonyl (PC) by a spectrophotometric method in the liver. RESULTS In the liver of pups, exposure to ethanol provoked a decrease in selenium and GPx activity and an increase in GR and CAT activity, as well as in carbonyl groups in protein. A pups had higher Se levels and GPx activity in serum than C pups. Administering Se with alcohol balances the activities of scavenging enzymes and reduces peroxidation protein products. CONCLUSION These results suggest that selenium could be effective in neutralizing the damage of ethanol consumption during gestation and lactation in pups since it repairs selenium levels in liver as well as the activity of scavenging enzymes and peroxidation protein products. In serum, Se also recovers GPx activity and increases the levels of Se that are available to other organs.

Effect of prenatal exposure to ethanol on hepatic elongation factor-2 and proteome in 21 d old rats: protective effect of folic acid.

In this article, we study the effects of ethanol intake during pregnancy and lactation on hepatic and pancreatic elongation factor-2 (EF-2) of 21 d old progeny. At the same time, the effect of ethanol on the level of other relevant hepatic proteins was determined using proteomic analysis. The results show that ethanol not only produces a general increase of protein oxidation, but also produces an important depletion of EF-2 and several other proteins. Among the hepatic proteins affected by ethanol, the concomitant supplementation with folic acid to alcoholic mother rats prevented EF-2, RhoGDI-1, ER-60 protease, and gelsolin depletion. This protective effect of folic acid may be related to its antioxidant properties and suggests that this vitamin may be useful in minimizing the effect of ethanol in the uterus and lactation exposure of the progeny.

Role of selenium and glutathione peroxidase on development, growth and oxidative balance in rat offspring.

Selenium (Se), an essential trace metal, is important in both growth and reproduction and is the constituent of different selenoproteins. The glutathione peroxidase (GPx) family is the most studied as it prevents oxidative stress. Liver oxidation is considered as another mechanism involved in low birth weight. Therefore, in order to ascertain whether GPx is related to the effects of Se on growth during gestation and lactation, three groups of rat pups were used: control, Se deficient (SD), and Se supplemented (SS). Morphological parameters and reproductive indices were evaluated. Hepatic Se levels were measured by graphite furnace atomic absorption while spectrophotometry was used for activity of antioxidant enzymes and oxidative stress markers in liver and western blotting for expression of hepatic GPx1 and GPx4. The SD diet increased mortality at birth; decreased viability and survival indices; and stunted growth, length, and liver development in offspring, thus decreasing hepatic Se levels, GPx, glutathione reductase, and catalase activities, while increasing superoxide dismutase activity and protein oxidation. The SS diet counteracted all the above results. GPx1 expression was heavily regulated by Se dietary intake; however, although Se dietary deficiency reduced GPx4 expression, this decrease was not as pronounced. Therefore, it can be concluded that Se dietary intake is intimately related to growth, length, and directly regulating GPx activity primarily via GPx1 and secondly to GPx4, thus affecting liver oxidation and development. These results suggest that if risk of uterine growth retardation is suspected, or if a neonate with low birth weight presents with signs of liver oxidation, it may be beneficial to know about Se status.

Ethanol Consumption by Wistar Rat Dams Affects Selenium Bioavailability and Antioxidant Balance in Their Progeny

Ethanol consumption affects maternal nutrition, the mothers’ antioxidant balance and the future health of their progeny. Selenium (Se) is a trace element cofactor of the enzyme glutathione peroxidase (GPx). We will study the effect of ethanol on Se bioavailability in dams and in their progeny. We have used three experimental groups of dams: control, chronic ethanol and pair-fed; and three groups of pups. Se levels were measured by graphite-furnace atomic absorption spectrometry. Serum and hepatic GPx activity was determined by spectrometry. We have concluded that ethanol decreased Se retention in dams, affecting their tissue Se deposits and those of their offspring, while also compromising their progeny’s weight and oxidation balance. These effects of ethanol are caused by a reduction in Se intake and a direct alcohol-generated oxidation action.

Oral or intraperitoneal binge drinking and oxidative balance in adolescent rats.

Oxidative imbalance is one of the most important mechanisms of alcohol-induced injury. Acute alcohol exposure induces a significant amount of reactive oxygen species during its hepatic metabolism via the microsomal ethanol oxidizing system. During adolescence, the physiological development is still taking place; therefore, ethanols effects differ in adolescents compared to that in adults. Because binge drinking is the most important model of ethanol intake used by adolescents and because little is known about its effects on the liver, we have used two routes of acute ethanol administration (oral and intraperitoneal) in adolescent rats in order to analyze the oxidative damage caused in the periphery and liver. Here, it has been demonstrated for the first time that binge drinking in adolescents causes peripheral oxidation of lipid and DNA as well as lipid and protein hepatic oxidation, which are related to lower glutathione peroxidise (GPx) activity, higher catalase (CAT) activity, and higher expression of NADPHoxidase, contributing to hepatic damage. In addition, it is shown that the intraperitoneal administration route results in increased oxidative damage, which is probably related to the resulting general stress response that causes higher DNA and protein oxidation due to higher NADPHoxidase expression and higher CAT and superoxide dismutase (SOD) activities. According to these results, it is concluded that binge drinking induces hepatic damage during adolescence, at least in part, as consequence of oxidative stress because the antioxidant response was insufficient to avoid liver oxidation. Alcohol administered intraperitoneally provoked more DNA oxidation than that from the oral alcohol exposure model.

Oxidative effects of chronic ethanol consumption on the functions of heart and kidney: folic acid supplementation.

AIMS The principal aim of this study was to investigate the oxidative effects of chronic ethanol consumption on the functions of the heart and the kidney and the possible modification of this effect by folic acid supplementation. Moreover, in order to find whether this oxidative profile affects cardiovascular function, parameters such as heart rate and glomerular filtration rate were also assessed. METHODS Four experimental groups of rats were used: control, ethanol-exposed, control supplemented with folic acid and ethanol-exposed plus folic acid. Ethanol-exposed rats were subjected to a chronic ethanol treatment (2 months), in which the level of alcohol reaches 30% v/v. Diet and ethanol solution were provided ad libitum, and folic acid supplementation was 8 vs. 2 ppm. Energy intake, creatinine clearance and heart rate were determined. Antioxidant enzyme activity and lipid and protein peroxidation of the kidney and the heart were measured by the spectrophotometric method. RESULTS Ethanol increases heart size and catalase (CAT) activity and decreases lipid peroxidation in heart without changing heart rate. However, in the kidney, ethanol decreases CAT activity, increases lipid peroxidation and decreases glomerular filtration rate. Folic acid supplementation avoids these situations; it does not, however, improve glomerular function. CONCLUSION Chronic ethanol consumption has many effects on the antioxidant enzymatic activity of the heart and the kidney, leading to increased renal lipid peroxidation prevented by folic acid supplementation.