Generalized peroxisomal disorder in male twins: fatty acid composition of serum lipids and response to n-3 fatty acids

Protective role of Ashwagandharishta and flax seed oil against maximal electroshock induced seizures in albino rats

Ashwagandharishta, an Ayurvedic classical formulation, is the remedy for Apasmara (epilepsy), Murchha (syncope), Unmada (psychosis), etc. Recent studies in animal models have shown that n-3 PUFAs can raise the threshold of epileptic seizures. The indigenous medicinal plant, called Atasi (Linum usitatissimum Linn.) in Ayurveda, or flax seed, is the best plant source of omega-3 fatty acids. The present study is designed to investigate whether Ashwagandharishta and Atasi taila (flax seed oil) protect against maximal electroshock (MES) seizures in albino rats. Further, a possible protective role of flax seed oil as an adjuvant to Ashwagandharishta in its anticonvulsant activity has also been evaluated in the study. MES seizures were induced for rats and seizure severity was assessed by the duration of hind limb extensor phase. Phenytoin was used as the standard antiepileptic drug for comparison. Both flax seed oil and Ashwagandharishta significantly decreased convulsion phase. Pre-treatment with flax seed oil exhibited significant anticonvulsant activity by decreasing the duration of tonic extensor phase. Contrary to the expectations, pre-treatment with flax seed oil as an adjuvant to Ashwagandharishta failed to decrease the tonic extensor phase; however, it significantly decreased the flexion phase (P < 0.001) and duration of the convulsions (P < 0.05). Both the drugs exhibited an excellent anti-post-ictal depression effect and complete protection against mortality.

Plasmalogen metabolism-related enzymes in rat brain during aging: influence of n-3 fatty acid intake

Plasmalogens (Pls) are phospholipids containing a vinyl-ether bond at the sn-1 position of the glycerol backbone. They represent between 1/2 and 2/3 of the ethanolamine phospholipids in the brain. During aging, the Pls content in human brain falls down. However, the role of Pls metabolism-related enzymes in the regulation of Pls levels remains to be determined. Dihydroxyacetone phosphate acyltransferase (DHAP-AT) is the enzyme involved in the first step of Pls biosynthesis. In the brain, a phospholipase A2, which selectively acts on Pls, has been isolated (Pls-PLA2s). In this work, we aimed to evaluate the impact of DHAP-AT (a key enzyme of Pls biosynthesis) and Pls-PLA2 (a specific Pls degradation enzyme) on the evolution of Pls content in the rat brain during aging. The influence of n-3 fatty acid intake was also evaluated. Littermates from two generations of n-3 deficient rats were fed an equilibrated diet containing either alpha-LNA alone or with two doses of DHA. After weaning, 3, 9 or 21 months of diet, rats were sacrificed. Enzymatic assays were performed, Pls levels were assessed and the sn-2 position of ethanolamine Pls was analyzed. DHAP-AT activity significantly increased between weaning and 3 months with a concomitant increase of brain Pls, which reached maximal levels after 9 months. Then, Pls levels and DHAP-AT activity significantly decreased while Pls-PLA2s activity significantly increased. Dietary n-3 fatty acids had no effect on DHAP-AT activity and on Pls levels. In conclusion, the increase of brain Pls content in the first part of the life may be related to the high increase of DHAP-AT activity, probably stimulated by DHA. In aged animals, the decrease of Pls levels may mainly be caused to an increase of their degradation by Pls-PLA2. Dietary DHA may not oppose the physiologic aging.

Diet enriched with omega-3 fatty acids alleviates convulsion symptoms in epilepsy patients

PURPOSE

We examined whether a dietary supplement containing omega-3 polyunsaturated fatty acids (n-3 PUFAs) can alleviate and/or reduce the frequency of epileptic seizures in patients with central nervous system (CNS) diseases treated with anticonvulsive drugs (ACDs).

METHODS

A special spread containing 65% n-3 PUFAs was added to the daily diet. The patients consumed 5 g of this spread at every breakfast for 6 months.

RESULTS

Five patients completed the study. In all of them, a marked reduction in both frequency and strength of the epileptic seizures was recorded.

CONCLUSIONS

Incorporation of the dietary supplement containing n-3 PUFAs may be beneficial in suppression of some cases of epileptic seizures.

Zellweger syndrome knockout mouse models challenge putative peroxisomal beta-oxidation involvement in docosahexaenoic acid (22:6n-3) biosynthesis

The putative involvement of peroxisomal beta-oxidation in the biosynthetic pathway of docosahexaenoic acid (22:6n-3, DHA) synthesis is critically reviewed in light of experiments with two recently developed knockout mouse models for Zellweger syndrome, a peroxisomal disorder affecting brain development. These mice were generated by targeted disruption of the PEX2 and PEX5 peroxisomal assembly genes encoding targeting signal receptor peroxins for the recognition and transport of a set of peroxisomal enzymes, including those of peroxisomal beta-oxidation, to the peroxisomal matrix. Analysis of esterified 22:6n-3 concentrations in PEX2-/- and PEX5-/- mice do not support the hypothesized requirement of peroxisomal beta-oxidation in 22:6n-3 synthesis, as only brain, but not liver or plasma, 22:6n-3 levels were decreased. Supplementation of PEX5+/- dams with 22:6n-3, although restoring the levels of brain 22:6n-3 in total lipids to that of controls, did not normalize the phenotype. These decreased brain 22:6n-3 concentrations appear to be secondary to impaired plasmalogen (sn-1-alkyl-, alkenyl-2-acyl glycerophospholipids) synthesis, probably at the level of the dihydroxyacetonephosphate acyltransferase (DHAP-AT), a peroxisomal enzyme catalyzing the first step in the synthesis of 22:6n-3-rich plasmalogens. To diminish the confounding effects of impaired plasmalogen synthesis in the brains of these Zellweger syndrome mouse models, kinetic experiments with labeled precursors, such as 18:3n-3 or 20:5n-3, in liver or isolated hepatocytes, which have negligible amounts of plasmalogens, are suggested to establish the rates of 22:6n-3 biosynthesis and precursor-product relationships. Similar experiments using brain of the acyl-CoA oxidase knockout mouse model are proposed to confirm the lack of peroxisomal beta-oxidation involvement in 22:6n-3 synthesis, since this mutation would not impair plasmalogen synthesis.