Eicosapentaenoic acid pre-treatment reduces biochemical changes induced in total brain and myelin of weanling Wistar rats by cuprizone feeding.

Recently, we investigated the effects of eicosapentaenoic acid (EPA), a fatty acid which modulates immune response and stimulates myelin gene expression, in an established model of multiple sclerosis (MS): the experimental autoimmune encephalomyelitis (EAE) induced in Dark Agouti rats. As scientific evidences and our previous studies have suggested that EPA could directly affect oligodendrocytes, we have now evaluated the effects of EPA in the non-immune mediate MS model characterized by selective oligodendrocytes damage induced by cuprizone (CPZ). We found that feeding weanling rats diets containing 0.6% CPZ for 2 weeks induced variation of whole brain and myelin biochemical composition representative of a severe myelin damage. We thus administered daily and by gavage EPA or PBS to 2-day old rats up to 21 days. Afterwards, rats were fed CPZ diet for 9 days. The results show that compared to PBS/CPZ fed rats, the whole brain cerebroside content in EPA pre-treated rats was statistically increased as well as there was an overall trend of increase of all other biochemical components.

Effect of micronutrient-enriched sunflower oils on plasma lipid profile and antioxidant status in high-fat-fed rats.

The main objective of this study was to evaluate in vivo whether micronutrient-enriched high-oleic sunflower oils (optimized oils) obtained using different crushing and refining procedures could have any beneficial effect on plasma lipid profile and antioxidant status. Sprague-Dawley rats were fed a high-fat diet for 4 weeks. The lipid source consisted of 20% optimized sunflower oils with different quantities and qualities of micronutrients. The control group received traditional refined high-oleic sunflower oil. The experimental optimized oils in the diets had a hypolipidemic effect. The reduction in plasma triglyceride and total cholesterol levels was 43% and 20%, respectively, in the group fed the diet with the highest levels of micronutrients. The serum ferric antioxidant capacity, superoxide dismutase, glutathione peroxidase and reduced glutathione significantly increased and lipid peroxidation decreased in parallel with the enhancement of micronutrients. These results suggest that a regular intake of optimized sunflower oils can help to improve lipid status and reduce lipid peroxidation in plasma.

Easy DNA extraction for rapid detection of Panax ginseng C. A. Meyer in commercial ginseng products.

An investigation was carried out in order to obtain an easy and rapid detection of Panax ginseng in commercial herbal products by using molecular techniques (polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP)). Two protocols and one commercial kit for DNA extraction were used. Four forms of commercial products were considered, i.e., dried body roots, dried root tails, dried root prongs and dried extracts. The RFLP of DNA amplified products by 18df/28ccr primers, obtained using Inf I, Sau 3A1 and Taq I endonucleases, allowed the identification of P. ginseng and its differentiation from P. quinquefolium. The presence of adulterants, as Mirabilis jalapa L. and Phytolacca acinosa Roxb. was excluded in the examined commercial samples. P. ginseng was detected in 63% of the considered samples according to the declaration of the labels, whereas negative results were obtained with the dried extract form. Therefore, the Invitrogen DNA extraction kit let the easy extraction of useful amounts of DNA and a standardisation of routine work, in comparison with the other molecular protocols so far used.

Polyunsaturated fatty acids and neurological diseases.

This review summarizes the knowledge of the role of dietary PUFAs, especially omega-3, on normal brain function. Furthermore, it reports the evidence pointing to potential mechanisms of omega-3 fatty acids in development of neurological disorders and efficacy of their supplementation in terms of symptom management.

Diet, lipids and brain development.

Brain development is a sequential anatomical process characterised by specific well-defined stages of growth and maturation. One of the fundamental and necessary events in the normal development of the central nervous system in vertebrates is the formation of a myelin sheath. It is becoming more evident that this process is influenced by dietary lipids. A number of findings have indicated that the administration of a diet deficient in essential fatty acids during development causes hypomyelination in the rat brain. Our studies have shown that lipids can also play a role in accelerating myelinogenesis in the brain of rats whose mothers had been fed, during pregnancy and lactation, a lipid fraction extracted from yeast grown on n-alkanes. Further studies have shown that accelerated myelinogenesis is connected to a precocious appearance of behavioural reflexes. Thus, the use of particular lipids in human nutrition must be carefully screened for possible effects on brain development.

The Myelinogenesis Process in Undernourished Rats Rehabilitated with Different Dietary Lipids.

Our previous studies have indicated that pups born from mothers fed lipids obtained from yeast (Candida lypolitica) grown on n-alkanes during pregnancy and lactation show an acceleration of myelinogenesis. In the present work we carried out experiments using an undernutrition model to establish if such microbial lipids can also play a role in accelerating the myelin process in hypomyelinated rats. This model was produced by restricting maternal dietary intake during the last 4 days of pregnancy and the lactating period. Diet-restricted dams were divided into 3 groups when pups were 14 days old. The first group was switched to ad libitum diet containing 9% margarine and 1% corn oil, the second to ad libitum feeding diet containing 10% of microbial lipids and the third to ad libitum feeding standard diet containing 3% of lipids. The offspring were sacrificed at differing days of nutritional rehabilitation. The recovery of the body and brain weight was slower in rats fed 3% of lipids than animals maintained on 10% of lipids. The test group showed an earlier increase both in the relative levels of proteolipid protein (PLP) and myelin oligodendrocyte glycoprotein (MOG) mRNAs and in the 2'-3'-cyclic nucleotide 3' phosphohydrolase (CNPase) activity compared with the other two groups. These results indicate that the reversal of myelin delay would seem to be accelerated in the group fed microbial lipids.

Effect of propylthiouracil-induced hypothyroidism on cerebral cortex of young and aged rats: lipid composition of synaptosomes, muscarinic receptor sites, and acetylcholinesterase activity.

The effect of hypothyroidism on the lipid composition of synaptosomes, density and affinity of muscarinic receptor sites, and acetylcholinesterase activity in the cerebral cortex of young and aged rats was investigated. The animals were made hypothyroid by adding 0.05% propyl-2-thiouracil to their drinking water for four weeks. This pathological state induced an increase in the relative percentage of sphingomyelin in young rats. In aged rats hypothyroidism induced a decrease of sphingomyelin and glycerophosphocholine and an increase of cholesterol. The effect of hypothyroid state on cerebral cortex resulted in an increase of acethylcholinesterase activity both in young and aged rats and was also reflected in an increase of density of M1-AChRs but only in the former.

Lipid changes in central nervous system membranes in experimental allergic encephalomyelitis (EAE).

Lipid composition of myelin fractions isolated from Lewis rats during the early stage of the development of experimental allergic encephalomyelitis (EAE) were determined by high-performance thin layer chromatography (HPTLC). When comparing the myelin fractions of EAE-affected animals with those of controls, the main differences were observed in the light fraction, where a decrease in the percentage of phospholipids (PH) relative to the total lipids was observed. These findings give further support that the light myelin fraction being the most sensitive at the onset of clinical symptoms must play a key role in demyelinating process.

Biochemical changes in central nervous system membranes in chronic-relapsing experimental allergic encephalomyelitis.

Biochemical studies of myelin fractions were undertaken on Lewis rats during various time-points in the development of chronic-relapsing experimental allergic encephalomyelitis (CR-EAE). Lipid and protein composition of myelin fractions obtained by sucrose density gradient centrifugation at 10, 19, 24, and 66 d postinduction (pi) were determined by high-performance thin-layer chromatography (HPTLC) and sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS PAGE), respectively. When comparing the myelin fractions of CR-EAE affected animals with those of controls, main differences were observed at 10 d pi. These changes were particularly evident in the light myelin fraction, where a decrease in the percentage of phosphatidylethanolamine and small basic protein relative to the total lipids and proteins of the fraction were observed. At 19 and 24 d pi no biochemical differences were present in both fractions. At 66 d pi, differences in the lipid composition were observed again only in the light myelin fraction. These findings suggest that the light myelin fraction is the most sensitive, particularly at the early stages of the disease, and must play a key role in demyelinating processes.