M. L. Murillo

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.

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.

Folate absorption in the jejunum of chronic ethanol-fed rats : In vivo studies

This study sought to determine the intestinal in vivo absorption of folic acid and methyltetrahydrofolate (MTHF) by jejunum surface at different times, after 20 weeks of 30% ethanol ingestion. The absorption results were compared with the data of control rats. In general after ethanol treatment jejunal folic acid absorption was higher than in control rats. When the folic acid concentrations in the perfusion medium were 0.5 microM an increase at later times in ethanol-fed rats was found. At 1 microM the folic acid absorption values were significantly higher at the earlier time. When the concentration assayed was 2.5 microM, significant modifications were only seen at 30 min. Results of MTHF absorption by jejunum of ethanol-fed rats were similar to absorption values of control rats. No significant differences between both groups were found. The results obtained in the present work suggested a different absorptive behavior of both substrates and a different effect of ethanol on folic acid and MTHF absorption in the jejunum.

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.

Intestinal Absorption and Enterohepatic Circulation of Folic Acid: Effect of Ethanol

This study sought to determine the intestinal in vivo absorption of folic acid by the whole intestine, and the appearance of this compound in bile in control and ethanol-fed rats. Intestinal folic acid absorption in rats with the bile duct cannulated decreased in ethanol-fed rats with respect to control rats. This difference was significant at 1 and 2.5 µM concentrations of folic acid. This result is in contrast with previous work in our laboratory on rats with intact bile ducts, where ethanol-fed rats had an increase in folic acid absorption. The results obtained in the present work suggest an impaired enterohepatic recycling of folic acid in ethanol-fed rats.

Comparative Effects of Intestinal Absorption of Folic Acid and Methyltetrahydrofolic Acid in Chronic Ethanol-Fed-Rats

This study concerns in vivo folic acid and methyltetrahydrofolic acid (MTHF) absorption by the whole intestinal surface after 20 weeks of 30% ethanol ingestion in drinking water. The results were compared with control rats fed ad libitum. The total intestinal serosal areas were similar in ethanol-fed and control rats. Significant increases in intestinal length, and decreases in tissue wet and dry weights were found in ethanol-fed rats. Serum folic acid concentrations were significantly less in the animals which had ingested ethanol than in the control rats. Intestinal folic acid absorption was significantly increased at lower substrate concentrations (0.5 and 1 microM), while no difference was observed at 2.5 microM in the ethanol-fed rats. Folic acid absorption relative to tissue wet weight showed significant increases at all tested concentrations in the ethanol-fed rats. Intestinal MTHF absorption showed no significant changes at 0.5 microM MTHF concentration, and an increase was observed in the absorption values at 1 and 2.5 microM concentrations in the ethanol-fed rats. When expressed as tissue wet weight, MTHF absorption values in ethanol-fed rats increased at 1 and 2.5 microM but did not differ at 0.5 microM substrate concentrations. The above results indicate compensatory responses in the folic acid and MTHF intestinal absorption after chronic ethanol ingestion. These effects are observed when the whole intestinal surface is evaluated.

Effect of chronic ethanol on D-galactose absorption by the rat whole intestinal surface

The in vivo absorption of D-galactose by rat whole intestinal surface after 4 weeks of 30% ethanol ingestion in drinking water has been studied, and the results were compared with ad lib-fed control rats. The total serosal intestinal area was determined by integration obtaining similar values between control and alcohol-treated groups. In the caecum surface of ethanol-fed rats slight but not significant increases were found, while the jejunum area decreased with respect to control rats. Total galactose absorption during 10 min of perfusion was slightly increased in ethanol-fed rats but these results were not significant with the substrate concentrations tested. When absorption data were referred to serosal surface, the absorption/cm2 values in ethanol-fed rats were increased at the studied galactose concentrations although these results were only statistically significant at 10 mM. In conclusion, the present data indicates a slight increase in D-galactose absorptive capacity by the whole intestine in ethanol-fed rats which suggest that the tissue traditionally not evaluated such as caecum and colon could modify the functional response to the absorption nutrients.