Effects of ethanol on steroid profiles in the rat testis

The effects of ethanol on the concentrations of steroids in testis was studied in adult rats. Testosterone, seven of its potential precursors, three of its metabolites, and estradiol were analyzed by gas chromatography-mass spectrometry of samples from testes removed 2 h after intraperitoneal administration of ethanol, 1.2 g/kg body weight. The same analyses were made on samples from control rats. Ethanol gave a marked increase of all 3 beta-hydroxy-delta 5 steroids analyzed: pregnenolone (60%), 17-hydroxypregnenolone (480%), dehydroepiandrosterone (430%) and 5-androstene-3 beta, 17 beta-diol (60%). This resulted in highly significant increases of the 3 beta-hydroxy-delta 5/3-oxo-delta 4 steroid ratios for all steroid couples analyzed. An analogous increase of the ratio between 5 alpha-androstane-3 beta, 17 beta-diol and dihydrotestosterone was also observed, whereas the ratio between androstenediol and dehydroepiandrosterone was decreased by ethanol. The concentration of estradiol was not affected. The results indicate that moderate doses of ethanol inhibit the conversion of 3 beta-hydroxy-delta 5 to 3-oxo-delta 4 steroids. This may be one mechanism by which ethanol decreases the production of testosterone.     

Effects of N-acetylcysteine on ethanol-induced hepatotoxicity in rats fed via total enteral nutrition

The effects of the dietary antioxidant N-acetylcysteine (NAC) on alcoholic liver damage were examined in a total enteral nutrition (TEN) model of ethanol toxicity in which liver pathology occurs in the absence of endotoxemia. Ethanol treatment resulted in steatosis, inflammatory infiltrates, occasional foci of necrosis, and elevated ALT in the absence of increased expression of the endotoxin receptor CD 14, a marker of Kupffer cell activation by LPS. In addition, ethanol treatment induced CYP 2 E1 and increased TNFalpha and TGFbeta mRNA expression accompanied by suppressed hepatic IL-4 mRNA expression. Ethanol treatment also resulted in the hepatic accumulation of malondialdehyde (MDA) and hydroxynonenal (HNE) protein adducts, decreased antioxidant capacity, and increased antibody titers toward serum hydroxyethyl radical (HER), MDA, and HNE adducts. NAC treatment increased cytosolic antioxidant capacity, abolished ethanol-induced lipid peroxidation, and inhibited the formation of antibodies toward HNE and HER adducts without interfering with CYP 2 E1 induction. NAC also decreased ethanol-induced ALT release and inflammation and prevented significant loss of hepatic GSH content. However, the improvement in necrosis score and reduction of TNFalpha mRNA elevation did not reach statistical significance. Although a direct correlation was observed among hepatic MDA and HNE adduct content and TNFalpha mRNA expression, inflammation, and necrosis scores, no correlation was observed between oxidative stress markers or TNFalpha and steatosis score. These data suggest that ethanol-induced oxidative stress can contribute to inflammation and liver injury even in the absence of Kupffer cell activation by endotoxemia.     

Dietary Zinc Deficiency Exaggerates Ethanol-Induced Liver Injury in Mice: Involvement of Intrahepatic and Extrahepatic Factors

Clinical studies have demonstrated that alcoholics have a lower dietary zinc intake compared to health controls. The present study was undertaken to determine the interaction between dietary zinc deficiency and ethanol consumption in the pathogenesis of alcoholic liver disease. C57BL/6N mice were subjected to 8-week feeding of 4 experimental liquid diets: (1) zinc adequate diet, (2) zinc adequate diet plus ethanol, (3) zinc deficient diet, and (4) zinc deficient diet plus ethanol. Ethanol exposure with adequate dietary zinc resulted in liver damage as indicated by elevated plasma alanine aminotransferase level and increased hepatic lipid accumulation and inflammatory cell infiltration. Dietary zinc deficiency alone increased hepatic lipid contents, but did not induce hepatic inflammation. Dietary zinc deficiency showed synergistic effects on ethanol-induced liver damage. Dietary zinc deficiency exaggerated ethanol effects on hepatic genes related to lipid metabolism and inflammatory response. Dietary zinc deficiency worsened ethanol-induced imbalance between hepatic pro-oxidant and antioxidant enzymes and hepatic expression of cell death receptors. Dietary zinc deficiency exaggerated ethanol-induced reduction of plasma leptin, although it did not affect ethanol-induced reduction of white adipose tissue mass. Dietary zinc deficiency also deteriorated ethanol-induced gut permeability increase and plasma endotoxin elevation. These results demonstrate, for the first time, that dietary zinc deficiency is a risk factor in alcoholic liver disease, and multiple intrahepatic and extrahepatic factors may mediate the detrimental effects of zinc deficiency.     

Ebselen as protection against ethanol-induced toxicity in rat stomach.

The mucosal protective effect of ebselen was examined in an ethanol-induced rat gastric lesion model. Examination of gastric tissue samples by light microscopy showed that i.g. exposure to 50% ethanol induced gastric injury, which was more prominent in female rats. Ethanol did not effect the gastric acid secretion examined by means of H(+)-K+ATPase, the increment of which might be harmful in the stomach. But ebselen with or without ethanol kept H(+)-K+ATPase below control levels. Gastric alcohol dehydrogenase (ADH) was mainly responsible for oxidation of ethanol in the stomach before it enters the bloodstream. I.g. ethanol exposure inhibited the ADH activity but ebselen eliminated the ethanol-induced inhibition of this enzyme. Therefore, ebselen exhibited a beneficial effect by increasing the gastric ethanol metabolism and by ameliorating the possible tissue toxicity of ethanol. Consistently, we also found that ebselen diminished the blood ethanol level. A gender difference in the blood ethanol levels existed following the same dose of ethanol but there was no difference in ADH activity. Histologically, mucosal injury following ebselen exposure together with ethanol was less severe compared with ethanol treatment alone. We concluded that the decrease in ethanol-induced mucosal injury following ebselen may have contributed to the inhibition of H(+)-K+ATPase and the activation of ADH by ebselen.     

Influence of sex hormones on ethanol-induced gastric haemorrhagic erosions in rats.

The role of sex hormones in the pathogenesis of ethanol-induced gastric erosions was investigated following the recent observation that ethanol generates more severe gastric damage in male rats. Female and male Wistar rats aged 110 +/- 6 days were used. Intact female, ovariectomized female, intact male, orchidectomized male and cyproterone acetate-pretreated (this compound a testosterone antagonist) male rats were investigated. 1 ml of 75% ethanol was used to induce gastric lesions. The extent of the erosions was determined planimetrically 60 min after ethanol administration. The plasma testosterone and 17-beta-oestradiol levels were checked by radioimmunoassay (RIA) in gonadectomized rats. Ethanol generates more severe lesions in male rats. Orchidectomy and cyproterone acetate treatment each reduced the extent of ethanol-induced gastric erosions in male rats. Ovariectomy had no effect in this model. The plasma testosterone and 17-beta-oestradiol levels were significantly reduced after gonadectomy. It is concluded that endogenous testosterone plays an aggressive role in the pathogenesis of ethanol-induced gastric erosions in rats.     

Acute ethanol increases angiogenic growth factor gene expression in rat skeletal muscle.

Moderate ethanol consumption demonstrates a protective effect against cardiovascular disease and improves insulin sensitivity, possibly through angiogenesis. We investigated whether 1) ethanol would increase skeletal muscle growth factor gene expression and 2) the effects of ethanol on skeletal muscle growth factor gene expression were independent of exercise-induced growth factor gene expression. Female Wistar rats were used. Four groups (saline + rest; saline + exercise; 17 mmol/kg ethanol + rest; and 17 mmol/kg ethanol + exercise) were used to measure the growth factor response to acute exercise and ethanol administration. Vascular endothelial growth factor (VEGF), transforming growth factor-beta(1) (TGF-beta(1)), basic fibroblast growth factor (bFGF), Flt-1, and Flk-1 mRNA were analyzed from the left gastrocnemius by quantitative Northern blot. Ethanol increased VEGF, TGF-beta(1), bFGF, and Flt-1 mRNA at rest and after acute exercise. Ethanol increased resting Flk-1 mRNA. Ethanol increased bFGF mRNA independently of exercise. These findings suggest that 1) ethanol can increase skeletal muscle angiogenic growth factor gene expression and 2) the mechanisms responsible for the ethanol-induced increases in VEGF, TGF-beta(1), and Flt-1 mRNA appear to be different from those responsible for exercise-induced regulation. Therefore, these results provide evidence in adult rat tissue that the protective cardiovascular effects of moderate ethanol consumption may result in part through the increase of angiogenic growth factors.     

Chronic ethanol consumption induces histopathological changes and increases nitric oxide generation in the rat liver

In the present work we evaluated the effect of ethanol consumption in histopathological liver changes and several biochemical biomarkers employed in the detection of hepatic dysfunction. Male Wistar rats were treated with ethanol 20% (vol/vol) for 6 weeks. Histopathological investigation of livers from ethanol-treated animals revealed steatosis. Indices of hepatic function (transaminases) and mitochondrial respiration were not altered in ethanol-treated rats. Chronic ethanol consumption did not alter malondialdehyde (MDA) levels in the liver. Ethanol consumption induced a significant increase on hepatic nitrite and nitrate levels. Treatment with ethanol increased both mRNA expression and immunostaining of iNOS, but not eNOS. Finally, ethanol consumption did not alter hepatic levels of metalloproteinase (MMP)-2 and MMP-9. We conclude that alterations on biochemical biomarkers (nitrite and nitrate levels) and histopathology occurred in ethanol-treated rats, supporting the practice of including both types of evaluation in toxicity studies to detect potential ethanol-related hepatic effects. In our model of ethanol consumption, histopathological liver changes were accompanied by elevation in nitrite and nitrate levels indicating increased nitric oxide (NO) generation. Since iNOS-derived NO contributes to hepatic injury, the increased levels of NO described in our study might contribute to a progressive hepatic damage. Therefore, increases in NO generation may be an early indicator of ethanol-induced liver damage.     

Effect of ninhydrin on the biochemical and histopathological changes induced by ethanol in gastric mucosa of rats

Studies on the effect of ninhydrin in the normal gastric mucosa and against the ethanol induced gastric injury were undertaken in rats in view of the presence of a carbonyl function as well as hydroxyl groups in its chemical structure. In spite of its potentials to generate hydroxyl radicals, it is deemed to possess antioxidant property by virtue of its electrophilic nature. Recent studies have shown gastro-protection to mediate through a reaction between the electrophilic compounds and sulfhydryl groups of the mucosa. Hence it was found worthwhile to evaluate the interaction between the oxidant and antioxidant functions in the structure of the same compound. The effects of ninhydrin pretreatment on gastric mucosal injuries caused by 80% ethanol, 25% NaCl and 0.2M NaOH were investigated in rats. The gastric tissue in ethanol-treated rats was analyzed for different histopathological lesions. In addition, the effects on ethanol-induced changes in the gastric levels of proteins, nucleic acids, non-protein sulfhydryl (NP-SH) and malondialdehyde (MDA) were also evaluated. Ninhydrin, as such, failed to induce any significant changes in normal gastric mucosa, while its pretreatment at oral doses of 5, 10 and 20 mg/kg was found to provide a dose-dependent protection against the ulcers induced by ethanol, NaOH and NaCl. The results of histopathological evaluation revealed a protective effect of ninhydrin on congestion, hemorrhage, edema, erosions and necrosis caused by ethanol. Furthermore, the pretreatment afforded a dose-dependent inhibition of the ethanol-induced depletion of proteins, nucleic acids, NP-SH and increase of MDA in the gastric tissue. The results obtained clearly demonstrate the anti-ulcerogenic activity of ninhydrin. The exact mechanism of action is not known. However, the carbonyl function in ninhydrin appears to achieve antioxidant balance and protect the gastric mucosa from the ethanol-induced gastric injury. Further studies are warranted to investigate the toxicity and detailed mechanism of action of this potent compound before any clinical trials, especially at the effective lower doses.     

Effects of chronic ethanol ingestion on steroid profiles in the rat testis

Testosterone, seven of its potential precursors, three of its metabolites and estradiol were analyzed in testes from rats given ethanol for 23 days in a nutritionally adequate liquid diet. The results were compared to those obtained with pair-fed control rats. The concentrations of pregnenolone, progesterone, 17-hydroxyprogesterone, androstenedione and testosterone were markedly lowered in four of the five rats given ethanol. The concentrations of the other 3 beta-hydroxy-delta 5 steroids and estradiol were unchanged, resulting in significantly increased ratios between 17-hydroxypregnenolone and 17-hydroxyprogesterone (P less than 0.025) and between androstenediol and testosterone (P less than 0.025) in the ethanol-treated rats. The results indicate that chronic ethanol administration reduces formation of testosterone by affecting a step prior to pregnenolone. There may also be an effect on the conversion of some 3 beta-hydroxy-delta 5 to the corresponding 3-oxo-delta 4 steroids. The levels of testosterone and three other steroids in testes of rats given the liquid diet were significantly lower than those in testes of animals fed a standard rat chow. This indicates a dietary influence on testicular steroid concentrations.     

Involvement of iron and iron-catalyzed free radical production in ethanol metabolism and toxicity

Lipoperoxidation, a degradative process of membranous polyunsaturated fatty acids, has been suggested to represent an important mechanism in the pathogenesis of ethanol toxicity on the liver and possibly also on the brain. Catalysis by transition metals, especially iron, is involved in the biosynthesis of free radicals contributing to lipid peroxidation. Although the exact nature of the redox-active iron implicated in this catalysis is still unknown, it has been well established that lipid peroxidation can be prevented in vitro by iron chelators such as desferrioxamine. Deprivation of redox-active iron through desferrioxamine inhibits by about 50% the microsomal oxidation of ethanol in vitro and reduces very significantly in vivo the overall ethanol elimination rate in rats. Administration of desferrioxamine together with ethanol also reduces the ethanol-induced disturbances in the antioxidant defense mechanisms of the hepatocyte. It also reduces in mice both the severity of physical dependence on ethanol and lethality following the acute administration of a narcotic dose of ethanol. Chronic overloading of rats with iron results, on the opposite, in an increased rate of ethanol elimination, although alcohol dehydrogenase and catalase activities are reduced and cytochrome P-450 depleted in the liver of such iron-overloaded animals. The magnitude of the ethanol-induced increase in lipid peroxidation and decrease in the major membranous antioxidant, alpha-tocopherol, is exacerbated in iron-overloaded rats. Several disturbances of iron metabolism have been reported in human alcoholics. Their contribution to ethanol toxicity appears very likely in the case of hepatic siderosis associated with alcohol abuse. Ethanol could however disturb iron metabolism even in the absence of gross abnormalities of the total iron stores. It is suggested that ethanol intoxication could increase cellular redox-active iron, thus contributing to an enhanced steady-state concentration of reactive-free radicals. This oxidative stress would lead to lipoperoxidative damage and cellular injury.     

AMP-dependent kinase and autophagic flux are involved in aldehyde dehydrogenase-2-induced protection against cardiac toxicity of ethanol

Mitochondrial aldehyde dehydrogenase-2 (ALDH2) alleviates ethanol toxicity although the precise mechanism is unclear. This study was designed to evaluate the effect of ALDH2 on ethanol-induced myocardial damage with a focus on autophagy. Wild-type FVB and transgenic mice overexpressing ALDH2 were challenged with ethanol (3 g/kg/day, ip) for 3 days and cardiac mechanical function was assessed using the echocardiographic and IonOptix systems. Western blot analysis was used to evaluate essential autophagy markers, Akt and AMPK, and the downstream signal mTOR. Ethanol challenge altered cardiac geometry and function as evidenced by enlarged ventricular end systolic and diastolic diameters, decreased cell shortening and intracellular Ca²⁺ rise, prolonged relengthening and intracellular Ca²⁺ decay, as well as reduced SERCA Ca²⁺ uptake, which effects were mitigated by ALDH2. Ethanol challenge facilitated myocardial autophagy as evidenced by enhanced expression of Beclin, ATG7, and LC3B II, as well as mTOR dephosphorylation, which was alleviated by ALDH2. Ethanol challenge-induced cardiac defect and apoptosis were reversed by the ALDH2 agonist Alda-1, the autophagy inhibitor 3-MA, and the AMPK inhibitor compound C, whereas the autophagy inducer rapamycin and the AMPK activator AICAR mimicked or exacerbated ethanol-induced cell injury. Ethanol promoted or suppressed phosphorylation of AMPK and Akt, respectively, in FVB but not ALDH2 murine hearts. Moreover, AICAR nullified Alda-1-induced protection against ethanol-triggered autophagic and functional changes. Ethanol increased GFP-LC3 puncta in H9c2 cells, the effect of which was ablated by Alda-1 and 3-MA. Lysosomal inhibition using bafilomycin A1, E64D, and pepstatin A obliterated Alda-1- but not ethanol-induced responses in GFP-LC3 puncta. Our results suggest that ALDH2 protects against ethanol toxicity through altered Akt and AMPK signaling and regulation of autophagic flux.     

Additive effect of alpha-tocopherol and ascorbic acid in combating ethanol-induced hepatic fibrosis

Abstract

Objective

To investigate the efficacy of combined administration of alpha-tocopherol (AT) and ascorbic acid (AA) in reducing ethanol-induced hepatotoxicity.

Methods

Rats were maintained for 90 days and grouped as follows: I – control rats, II – ethanol, III – alpha-tocopherol, IV – ethanol + alpha-tocopherol, V – AA, VI – ethanol + ascorbic acid, VII – alpha-tocopherol + ascorbic acid, VIII – ethanol + alpha-tocopherol + ascorbic acid. At the end of the experimental period, markers of hepatic function, oxidative stress, and the expression of markers of inflammation and fibrosis were assayed.

Results

The markers of hepatic function, lipid peroxidation products, protein carbonyls, and the expression of nuclear factor kappa B, tumor necrosis factor alpha, transforming growth factor beta 1, cytochrome P4502E1, and collagen Type I were elevated after ethanol administration. All these parameters were reduced in the ethanol group administered AT and AA in combination. The activities of antioxidant enzymes which were reduced by ethanol administration were enhanced on combined administration of AT and AA. The reduction in hepatic fibrosis was almost 20% more in AT and AA co-administered group compared with AT and AA alone treated groups.

Discussion

Combined administration of fat soluble AT and water soluble AA was beneficial against ethanol-induced hepatotoxicity. This may be due to their different subcellular localizations.     

Inhibition of testosterone biosynthesis by ethanol. Relation to hepatic and testicular acetaldehyde, ketone bodies and cytosolic redox state in rats.

In experiments in which liver and testis freeze-stops were performed on pentobarbital-anaesthetized rats, ethanol (1.5 g/kg body wt.) reduced plasma testosterone concentration from 13.1 to 3.2 nmol/litre. 4-Methylpyrazole abolished the ethanol-induced hepatic and testicular increase in the lactate/pyruvate ratio, and the testicular acetaldehyde level, but did not diminish the reduction in plasma testosterone concentration. In testes, but not in liver, ethanol decreased the 3-hydroxybutyrate/acetoacetate ratio, and 4-methylpyrazole did not prevent this effect. In experiments in which freeze-stop was performed after cervical dislocation, ethanol decreased the testis testosterone concentration from 590 to 220 pmol per g wet wt. The effects of ethanol and 4-methylpyrazole on testis acetaldehyde, lactate/pyruvate and 3-hydroxybutyrate/acetoacetate ratios were the same as found during anaesthesia. The NAD+-dependent ethanol oxidation capacity in testis ranged from 0.1 to 0.2 mumol/min per g wet wt. and seemed to be inhibited by 4-methylpyrazole both in vivo and in vitro. In additional experiments, ethanol doses between 0.3 and 0.9 g/kg body wt. did not alter the plasma testosterone concentration in rats treated, or not treated, with cyanamide, which induced elevated acetaldehyde levels in blood and testes. The results suggest that ethanol-induced inhibition of testosterone biosynthesis was not caused by extratesticular redox increases, or by extra- or intra-testicular acetaldehyde per se. The inhibition is accompanied by changes in testicular ketone-body metabolism.     

Mast cell stabilizator and antioxidant effects of epidermal growth factor (EGF) on gastric mucosal injury induced by ethanol in rats

The role of epidermal growth factor (EGF), a polypeptide containing 53 amino acids, on protection and repair of ethanol-induced gastric mucosal injury was investigated in rats. In addition, the effects of EGF on the gastric damage were evaluated histopathologically. We used 48 Spraque-Dawley rats which were divided into [corrected] three groups as control rats, ethanol treated rats and ethanol+EGF treated rats. The ethanol group was given a gastric gavage containing 1 ml of 80% ethanol (v/v) prepared in distilled water. EGF (100 microg/kg) was given by intragastric gavage 30 min before the administration of ethanol. We studied histopathological evaluation and the histochemical heterogeneity of mast cells and its degree of degranulation. Besides, gastric tissue malondialdehyde (MDA), protein sulfhydryl groups (SH), and protein carbonyl levels were measured. EGF treatment stabilized mast cells degranulation and had lower polymorphonuclear leukocytes (PMNL) infiltration, ulcer index, histamine, and MDA; protein carbonyl levels were also lower, compared to the non-treated animals. EGF exerts a protective effect on gastric mucosa to ethanol-induced gastric injury probably through antioxidant and mast cell stabilizing mechanism.     

Short-term inhibition of carnitine palmitoyltransferase I activity in rat hepatocytes incubated with ethanol

Ethanol decreased the activity of carnitine palmitoyltransferase I and the rate of fatty acid oxidation in rat hepatocytes in short-term incubations. These effects were mimicked by acetaldehyde, the product of hepatic ethanol metabolism, and were absent when ethanol oxidation was prevented by 4-methylpyrazole. Ethanol was also able to increase intracellular malonyl-CoA levels. The results suggest that inhibition of fatty acid translocation into mitochondria may play an important role in the ethanol-induced inhibition of hepatic fatty acid oxidation.     

On the mechanism of ethanol-induced fatty liver and its reversibility by adenosine.

The administration of adenosine partially prevented and reverted the ethanol-induced fatty liver. The hepatic α-glycerophosphate concentration and the α-glycerophosphate/dihydroxyacetone phosphate ratio were significantly increased after ethanol administration. The nucleoside decreased with ratio and enhanced the oxidation of ethanol. A strong correlation between the cytoplasmic redox state and the amount of triacylglycerols in the liver was found (8 h after treatments) stressing the paramount importance of the redox state in the pathogenesis of ethanol-induced fatty liver. As previously reported, the nucleoside expanded the adenine nucleotide pool size and the hepatic ATP level. Ethanol potentiated these effects. It is suggested that adenosine ameliorated the ethanol-induced fatty liver through an increased utilization of reducing equivalents by the mitochondria. An interdependence of these effects is proposed and discussed.     

Ethanol-induced hypothermia. Cross tolerance with morphine

The development of tolerance to ethanol-induced hypothermia and hypnosis, and cross-tolerance with morphine was studied in mice and rats. Ethanol significantly decreased the body temperature in rats (3.0 and 3.2 g/kg) and in mice (3.5 and 4.0 g/kg). Chronic administration of ethanol resulted in the tolerance not only to ethanol hypothermia but also to hypothermic effects of morphine in examined animals. Implantation of morphine pellets caused the development of cross tolerance to ethanol-induced hypothermia in rats but not in mice. The hypnotic effect of ethanol was significantly shorter in chronic alcoholized rats but not in morphine-implanted rats. Neither chronic ethanol administration nor implantation of morphine pellets changed the duration of ethanol-induced hypnosis in mice. These results seem to support the hypothesis on the opiate-like mechanism of ethanol action.     

Effect of bax deletion on ethanol sensitivity in the neonatal rat cerebellum

The developing cerebellum is highly sensitive to ethanol during discrete neonatal periods. This sensitivity has been linked to ethanol-induced alterations in molecules of the Bcl-2 survival-regulatory gene family. Ethanol exposure during peak periods of cerebellar sensitivity, for example, results in increased expression of proapoptotic proteins of this family, while overexpression of the antiapoptotic Bcl-2 protein in the nervous system protects against ethanol neurotoxicity. For the present study, neonatal mice with a targeted deletion of the proapoptotic bax gene were used to determine whether elimination of this protein would mitigate ethanol toxicity. bax knock-out and wild-type mice pups were exposed to ethanol via vapor inhalation during the maximal period of neonatal cerebellar ethanol sensitivity and cerebellar tissue was subsequently assessed for Purkinje and granule cell number and ethanol-mediated generation of reactive oxygen species (ROS). The results revealed that: (1) ethanol exposure during the peak period of cerebellar vulnerability resulted in substantial loss of Purkinje cells in wild-type animals, but not in bax knock-outs; (2) granule cells in the bax gene-deleted animals were not similarly protected from ethanol effects; and (3) levels of ROS following acute ethanol exposure were appreciably enhanced in the wild-type animals but not in the bax knock-outs. These results imply that Bax is important to ethanol-induced Purkinje cell death during critical neonatal periods, but that ethanol effects on granule cells may function at least partially independent of this apoptosis agonist. Amelioration of ethanol-mediated increases in ROS production in the knock-outs may contribute to the observed effects.     

Myocardial antioxidant status and oxidative stress after combined action of exercise training and ethanol in two different age groups of male albino rats

The interaction of exercise training and ethanol on the myocardial antioxidant enzymes and the oxidative stress markers was investigated in the Wistar strain male albino rats. We also tested the interactive effects of exercise training and ethanol on the age-associated free radical production and antioxidant defense system. We found a significant decrease (p<0.05) in the activity levels of superoxide dismutase (SOD) and catalase (CAT) in the myocardium of old rats when compared to young rats by 26% and 58%, respectively, suggesting the onset of age-dependent decrease in the myocardial antioxidant enzyme system. In contrast to the decreased antioxidant enzyme activity, xanthine oxidase (XOD) and lipid peroxidation (LPO) levels were elevated, suggesting the age-induced oxidative stress. Exercise training significantly (p < 0.05) elevated the activities of SOD, CAT, XOD and LPO levels in both the age groups of animals. Ethanol consumption significantly lowered the SOD and CAT activities in both the age groups, whereas a significant increase was observed in the XOD and LPO levels. In contrast, the combination of exercise training plus ethanol lowered XOD and LPO levels in both the age groups of rats compared to ethanol treated rats. A significant (p < 0.05) increase in the activities of SOD and CAT was reported in the rats treated with the combination of exercise training plus ethanol. This increase was more pronounced in the younger rats than the older rats. The findings of the present investigation on the potential role of antioxidant enzymes to counter the ethanol-induced pro-oxidants showed an increase with the interaction of exercise training. With age, a decrease in the antioxidant enzyme capacity was observed. This reveals that the old age rats were more affected to the pro-oxidants when compared to the young age rats. In conclusion it is demonstrated that two months treadmill endurance exercise training is beneficial to both young and old rats in improving antioxidant defense to challenge the oxidative stress in the myocardial tissue and thereby successfully countering the free radical production due to ethanol intoxication.     

Lycopene attenuates alcoholic apoptosis in HepG2 cells expressing CYP2E1

To test the hypothesis that ethanol-induced hepatic apoptosis is secondary to the oxidative stress generated by cytochrome P4502E1 (CYP2E1), we assessed the effects of the carotenoid lycopene, a potent antioxidant extracted from tomatoes, on oxidative stress and apoptosis in HepG2 cells overexpressing CYP2E1 (2E1 cells). These were exposed for 5 days to 100mM ethanol and 10 microM lycopene or an equal volume of placebo (vehicle). Ethanol significantly increased apoptosis measured by flow cytometry and by TUNEL assay. This was accompanied by an ethanol-induced oxidative stress: hydrogen peroxide production was significantly increased and mitochondrial GSH was strikingly decreased. Both were restored by lycopene, with a significant decrease in apoptosis. The placebo had no protective effect. In conclusion, Lycopene opposes the ethanol-induced oxidative stress and apoptosis in 2E1 cells. The parallelism between these effects suggests a causal link. Furthermore, these beneficial effects and the innocuity of lycopene now justify an in vivo trial.