Alteration of alpha-tocopherol content in the developing and aging peripheral nervous system: persistence of high correlations with total and specific (n-6) polyunsaturated fatty acids

Olive oil-enriched diet reduces brain oxidative damages and ameliorates neurotrophic factor gene expression in different life stages of rats

Our aim was to assess the influence of maternal diet rich in monounsaturated fatty acids on oxidative and molecular parameters in brains of mouse pups as well as their body weight during their lifetime. Female rats received a diet containing 20% of olive oil-enriched diet (OOED) and a standard diet control diet (CD) in different periods: pregnancy, lactation and after weaning until pups' adulthood. On the last prenatal day (Group 1), embryos from OOED group showed smaller body weight, brain weight and lower levels of sulphydryl groups glutathione reduced (GSH) in the brain. On postnatal delay-21 (PND21) (Group 2), pups from OOED group showed higher body weight and brain weight, reduced brain weight/body weight ratio and lower brain lipid peroxidation (LP). On PND70 (Group 3), pups from OOED group showed lower brain LP and higher levels of GSH in prefrontal cortex and lower brain levels of reactive species in the hippocampus. Interestingly, the group of animals whose diet was modified from OOED to CD on PND21 showed greater weight gain compared to the group that remained in the same original diet (OOED) until adulthood. Furthermore, OOED consumption during pregnancy and lactation significantly increased BDNF only, as well as its main transcripts exon IV and VI mRNA levels in the prefrontal cortex. In addition, OOED significantly up-regulated FGF-2 mRNA levels in the prefrontal cortex. These findings open a pioneering line of investigation about dietary adjunctive therapeutic strategies and the potential of healthy dietary habits to prevent neonatal conditions and their influence on adulthood.

LPO and Antiradical Defense Processes in the Liquor of Patients wit Severe Craniocerebral Injury

Acute posttraumatic period of severe craniocerebral trauma is associated with sharp activation of LPO processes and rapid exhaustion of antioxidant enzymes and especially low-molecular-weight antioxidant system in the liquor. This leads to the development of severe oxidative stress and failure of adaptation processes during the early posttraumatic period.

Lipid peroxidation and glutathione system in hyperlipemic rabbits: influence of olive oil administration

We studied the effect of supplementation (10% w/w) of a hyperlipemic diet (1% cholesterol) with olive oil (OLIV) for 6 weeks in four groups of 10 rabbits each. At the end of this period, we determined lipid peroxidation, glutathione content, and glutathione peroxidase, reductase and transferase activities in liver, brain, heart, aorta and platelets. The atherogenic diet increased tissue lipid peroxidation and decreased the protective antioxidant effect of glutathione. Dietary supplementation with olive oil reduced tissue lipid peroxidation by 71.6% in liver, 20.3% in brain, 84.5% in heart, 63.6% in aorta, 72% in platelets. The ratios total/oxidized glutathione were increased in all tissues (49% in liver, 48% in brain, 45% in heart, 83% in aorta, 70% in platelets). Olive oil increased glutathione peroxidase and transferase activities in all tissues. We conclude that in rabbits made hyperlipemic with a diet rich in saturated fatty acids, olive oil decreased tissue oxidative stress.

Antioxidant potential of evening primrose oil administration in hyperlipemic rabbits

The dietary intake of saturated fatty acids affects arteriosclerosis. We studied the effect of supplementation (15% wt/wt) of a hyperlipemic diet (1.33% cholesterol) with evening primrose oil (EPO) (Oenothera biennis) for 6 weeks in four groups of 10 rabbits each. At the end of this period we determined lipid peroxidation, glutathione content, and glutathione peroxidase, reductase and transferase activities in liver, brain, heart, aorta and platelets. The atherogenic diet increased tissue lipid peroxidation and decreased the protective antioxidant effect of glutathione. Dietary supplementation with EPO reduced tissue lipid peroxidation (61% in liver, 57% in brain, 42% in heart, 24% in aorta, 33% in platelets). Total glutathione was increased, especially in the aorta (90%) and platelets (200%); however, in all tissues the percentage of oxidised glutathione decreased. Evening primrose oil reduced glutathione peroxidase activity and increased the activities of glutathione reductase and transferase. We conclude that in rabbits made hyperlipemic with a diet rich in saturated fatty acids, EPO decreased tissue oxidative stress.

Ascorbate-stimulated lipid peroxidation and non-heme iron concentrations in Alzheimer disease

Lipid peroxidation has been suggested to be a potential cause of neuronal damage in neurodegenerative diseases. Changes in several parameters of lipid peroxidation, including basal (unstimulated) lipid peroxidation, stimulated lipid peroxidation, tissue iron concentrations, and the concentrations of some oxygen radical scavengers, have been reported in neurodegenerative diseases. However, the in vitro interaction of oxygen radical scavengers and stimulated lipid peroxidation in neurodegenerative disease has been less well-studied. The purpose of the present study was to determine the effects of oxygen radical scavengers on ascorbate-stimulated lipid peroxidation in Alzheimer disease (AD). We have found that some parameters of ascorbate-stimulated lipid peroxidation are altered in AD and that the effects of superoxide dismutase (SOD) on ascorbate-stimulated lipid peroxidation are significantly different in AD as compared to aged.

Alteration of brain and liver microsomal polyunsaturated fatty acids following dietary vitamin E deficiency

The effects of dietary vitamin E deficiency on fatty acid composition of brain and liver microsomes were studied in rats fed a vitamin E-deficient diet for 9 weeks. In brain microsomes, vitamin E deficiency resulted in a significant decrease in palmitic acid and total saturated fatty acids. Cervonic acid was increased. In contrast, no marked changes were observed in the levels of (n-6) polyunsaturated fatty acid (PUFA). In liver microsomes, vitamin E deficiency resulted in significant alterations in fatty acid composition: higher amounts of stearic acid and total saturated fatty acids, lower amounts of mono-unsaturated fatty acids, linoleic and dihomo gamma linoleic acids. In contrast, arachidonic acid was not altered. The overall decrease in the amounts of (n-6) PUFA was compensated by an increase in the level of (n-3) PUFA. It is concluded that vitamin E may alter the enzymatic activities of chain elongation-desaturation and the relationship between vitamin E and PUFA in brain and liver microsomes.

Nodal and terminal sprouting by regenerating nerve in vitamin E-deficient rats

The increased number of poly-innervated cells in normal and reinnervated extensor digitorum longus (edl) muscle of vitamin E-deficient rats suggests enhanced sprouting by motor neurons in conditions of decreased protection against lipid peroxidation. End-plates and terminal axons were observed by a combined technique that shows both end-plate acetylcholinesterase area and axons. Quantitative observations of nodal and terminal sprouting in normally innervated and reinnervated edl muscles of vitamin E-deficient rats were carried out. Branch points of nerve terminal within end-plates were also observed. Three main results were obtained. First, a notable increase of both terminal and nodal sprouting was found in reinnervated muscles of normal and vitamin E-deficient rats; moreover, a relative increase in the number of nodal sprouts occurs in the long run. Second, in muscles of uninjured, vitamin E-deficient rats, nodal and terminal sprouting and branching within end-plate was greater than in controls. Third, nodal sprouting by regenerating axons was more affected by vitamin E-deficiency than terminal sprouting and branching within end-plates.

Function of dietary polyunsaturated fatty acids in the nervous system

The brain is the organ with the second greatest concentration of lipids; they are directly involved in the functioning of membranes. Brain development is genetically programmed; it is therefore necessary to ensure that nerve cells receive an adequate supply of lipids during their differentiation and multiplication. Indeed the effects of polyunsaturated fatty acid (PUFA) deficiency have been extensively studied; prolonged deficiency leads to death in animals. Linoleic acid (LA) is now universally recognized to be an essential nutrient. On the other hand, alpha-linolenic acid (ALNA) was considered non-essential until recently, and its role needs further studies. In our experiments, feeding animals with oils that have a low alpha-linolenic content results in all brain cells and organelles and various organs in reduced amounts of 22:6(n-3), compensated by an increase in 22:5(n-6). The speed of recuperation from these anomalies is extremely slow for brain cells, organelles and microvessels, in contrast with other organs. A decrease in alpha-linolenic series acids in the membranes results in a 40% reduction in the Na-K-ATPase of nerve terminals and a 20% reduction in 5'-nucleotidase. Some other enzymatic activities are not affected, although membrane fluidity is altered. A diet low in ALNA induces alterations in the electroretinogram which disappear with age: motor function and activity are little affected but learning behaviour is markedly altered. The presence of ALNA in the diet confers a greater resistance to certain neurotoxic agents, i.e. triethyl-lead. We have shown that during the period of cerebral development, there is a linear relationship between brain content of (n-3) acids and the (n-3) content of the diet up to the point where alpha-linolenic levels reach 200 mg for 100 g food intake. Beyond that level there is a plateau. For the other organs, such as the liver, the relationship is also linear up to 200 mg/100 g, but then there is merely an abrupt change in slope and not a plateau. By varying the dietary 18:2(n-6) content, it was noted that 20:4(n-6) optimum values were obtained at 150 mg/100 g for all nerve structures, at 300 mg for testicle and muscle, 800 mg for the kidney, and 1200 mg for the liver, lung and heart. A deficiency in ALNA or an excess of LA has the same main effect: an increase in 22:5(n-6) levels.(ABSTRACT TRUNCATED AT 400 WORDS)

Increased number of dorsal root ganglion neurons in vitamin-E-deficient rats

Quantitative and morphometric observations were carried out on neurons of L3-L6 dorsal root ganglia (DRGs) in control and vitamin-E-deficient rats at different ages. Controls were fed a standard diet and sacrificed at 1 or at 5 months of age; deficient rats were fed a diet without vitamin E from 1 to 5 months of age and then sacrificed. No significant difference in total number of neurons was found, but an increase in neuron sizes, a decrease in nucleus-cytoplasm ratio, and a more circular neuron shape were found in controls with increasing age (from 1 to 5 months). In L3-L6 DRGs of vitamin-E-deficient rats (5 months of age), a higher number of neurons was found than in those of either young or adult controls. Moreover, some morphometric characteristics of neurons in the deficient rats were similar to those of neurons in 1-month-old controls. The findings suggest that vitamin E deficiency can trigger events resulting in appearance of new neurons, possibly anticipating phenomena that normally occur in aging.

Alteration of delta-6 desaturase by vitamin E in rat brain and liver

delta-6 Desaturase, measured at substrate saturation using linoleic acid, was found to be increased by more than two-fold when the content of vitamin E in brain microsomal membrane suspension was increased (up to 7.5 micrograms/mg membrane protein, i.e. 100 micrograms/g tissue from which microsomes were prepared). In contrast, this activity was reduced by 25% in the liver. This raises the question of the multiple role of vitamin E in membranes, the control of membrane polyunsaturated fatty acids through synthesis, and their protection against peroxidation.

Do essential fatty acids play a role in brain and behavioral development?

The membrane phospholipids of the brain contain high levels of polyunsaturated fatty acids (PUFA), particularly arachidonic acid, 20:4n-6 and docosahexaenoic acid, 22:6n-3. These long-chain PUFA are synthesized from their respective essential fatty acid (EFA) precursors, linoleic acid, 18:2n-6 and linolenic acid, 18:3n-3. Although the necessity of n-6 fatty acids for optimum growth has been established, a similar requirement for those of the n-3 family is less clear. The rapid accumulation of the long-chain n-3 PUFA in the brain during prenatal and preweaning development suggests that the provision of n-3 fatty acids to the developing brain may be necessary for normal growth and functional development. The intent of this review is to assess the experimental work which addresses this question, most of which has been conducted on rodents. The emphasis will be on studies which measure behavioral outcomes, and particular attention will be paid to methodological issues which affect the interpretation of these data. An integration of the research findings will be presented and discussed in light of possible implications for therapeutic interventions.

Structural and functional importance of dietary polyunsaturated fatty acids in the nervous system

The nervous system is the organ with the second greatest concentration of lipids. These lipids participate directly in membrane functioning. Brain development is genetically programmed. It is therefore necessary to ensure that nerve cells receive an adequate supply of nutrients, especially of lipids, during their differentiation and multiplication, and throughout their lives. The effects of polyunsaturated fatty acid deficiency have been extensively studied; prolonged deficiency leads to death in animals. Linoleic acid is now universally recognized to be an essential nutrient. Until recently, however, alpha-linolenic acid was considered non-essential. Feeding animals with oils that have a low alpha-linolenic content results in all brain cells and organelles and various organs having reduced amounts of 22:6n-3, which is compensated for by an increase in 22:5n-6. The speed of recuperation from these anomalies is extremely slow for brain cells, organelles, and microvessels, in contrast to other organs. A decrease in alpha-linolenic series acids in the membranes results in a 40% reduction in the Na(+)-K(+)-ATPase of nerve terminals and a 20% reduction in 5'-nucleotidase. Some other enzymatic activities are not affected, although membrane fluidity is altered. A diet low in alpha-linolenic acid induces alterations in the electroretinogram which disappear with age; motor function and activity are little affected, but learning behavior is markedly altered. The presence of alpha-linolenic acid in the diet confers a greater resistance to certain neurotoxic agents (triethyl-lead). During the period of cerebral development, there is a linear relationship between brain content of n-3 acids and the n-3 content of the diet up to the point where alpha-linolenic levels reach 200 mg for 100 g of food intake. Beyond that level there is a plateau. For other organs, such as the liver, the relationship is also linear up to 200 mg/100 g, but then there is merely an abrupt change in slope and not a plateau. When dietary 18:2n-6 content was varied, it was noted that 20:4n-6 optimum values were obtained at 150 mg/100 g for all nerve structures, 300 mg for testicle and muscle, 800 mg for kidney, and 1200 mg for liver, lung and heart. A deficiency in alpha-linolenic acid and an excess of linoleic acid have the same main effect: an increase in 22:5n-6 levels.(ABSTRACT TRUNCATED AT 400 WORDS)

Alzheimer's and Parkinson's disease. Brain levels of glutathione, glutathione disulfide, and vitamin E

Human brain levels of glutathione (GSH), glutathione disulfide (GSSG), and vitamin E were measured in neurologically normal control patients and two groups of patients with neurodegeneration: those with Alzheimer's disease (AD), and AD with some features of Parkinson's disease (AD-PD). Control brain samples contained GSH levels more than 50 times higher than GSSG. The levels of GSH were highest in the caudate nucleus and lowest in the medulla. In patients with AD or AD-PD, hippocampal levels of GSH were significantly higher than controls. Patients with AD also demonstrated high GSH levels in the midbrain compared to normal. In contrast, patients with AD-PD did not have significantly elevated GSH levels in this site. GSSG levels were not significantly different in any brain region between controls and diseased patients. In control brains, the medulla had higher levels of vitamin E than any other brain region. The caudate nucleus had the lowest levels, which were about half the levels in the medulla. Control levels of vitamin E in the midbrain were about 18.8 micrograms/g. In AD patients the midbrain levels of vitamin E doubled to 42.3 micrograms/g. This doubling also occurred in AD-PD patients where midbrain vitamin E levels increased to 44.0 micrograms/g. These results may indicate that compensatory increases in GSH and vitamin E levels occur following damage to specific brain regions in patients with AD or AD-PD.