Uptake and metabolism of plasma-derived erucic acid by rat brain

Review of the potential pharmacological role of erucic acid: a monounsaturated omega-9 fatty acid

This comprehensive review aims to provide an overview of the pharmacological properties of erucic acid (EA) and highlight areas that require further research. EA is an omega-9 fatty acid found in certain vegetable oil, such as rapeseed oil has demonstrated favourable effects in rodents, including ameliorating myocardial lipidosis (fat accumulation in the heart muscle), congestive heart disease, hepatic steatosis (fat accumulation in the liver), and memory impairments. These findings have prompted regulatory bodies to establish limits on EA content in food oils. The studies were performed on rodents and led to caution on ingesting the EA at high levels. Moreover, EA is frequently utilized as a nutritional supplement for the treatment of adrenoleukodystrophy, myocardial disease, and memory improvement. The review of the article indicated that EA improves cognitive function, has a part in Huntington's disease, interacts with peroxisome proliferator-activated receptors, inhibits elastase and thrombin, has anti-inflammatory, antioxidant, and anti-tumour properties, and inhibits influenza A virus. This article elucidates the pharmacological effects of EA, an omega-9 fatty acid.

Erucic Acid: A Possible Therapeutic Agent for Neurodegenerative Diseases

Neurodegenerative disorders are among the most common life-threatening disorders among the elderly worldwide and are marked by neuronal death in the brain and spinal cord. Several studies have demonstrated the beneficial role of dietary fatty acids in different brain disorders. This is due to their neurotrophic, antioxidant, and anti-inflammatory properties. Furthermore, extensive evidence shows that an unbalanced intake of certain dietary fatty acids increases the risk of neuropsychiatric diseases. Several research has been done on erucic acid, an ingestible omega-9 fatty acid that is found in Lorenzo's oil. Erucic acid was previously thought to be a natural toxin because of its negative effects on heart muscle function and hepatic steatosis, but it has been discovered that erucic acid is regularly consumed in Asian countries through the consumption of cruciferous vegetables like mustard and rapeseed oil with no evidence of cardiac harm. Erucic acid can also be transformed into nervonic acid, a crucial element of myelin. Therefore, erucic acid may have remyelinating effects, which may be crucial for treating different demyelinating conditions. Also, erucic acid exerts antioxidant and anti-inflammatory effects, suggesting its possible therapeutic role in different neurodegenerative disorders. Considering the fruitful effects of this compound, this article reviews the probable role of erucic acid as a pharmacological agent for treating and managing different neurodegenerative disorders.

Newborn screening for X-linked adrenoleukodystrophy in Italy: Diagnostic algorithm and disease monitoring

Introduction

X-linked adrenoleukodystrophy (X-ALD) is the most common inherited peroxisomal disorder caused by variants in the ABCD1 gene. The main phenotypes observed in men with X-ALD are primary adrenal insufficiency, adrenomyeloneuropathy, and cerebral ALD (cALD). Cerebral ALD consists of a demyelinating progressive cerebral white matter (WM) disease associated with rapid clinical decline and is fatal if left untreated. Hematopoietic stem cell transplantation is the standard treatment for cALD as it stabilizes WM degeneration when performed early in the disease. For this reason, early diagnosis is crucial, and several countries have already implemented their newborn screening programs (NBS) with the assessment of C26:0-lysophosphatidylcholine (C26:0-LPC) values as screening for X-ALD.

Methods

In June 2021, an Italian group in Lombardy launched a pilot study for the implementation of X-ALD in the Italian NBS program. A three-tiered approach was adopted, and it involved quantifying the values of C26:0-LPC and other metabolites in dried blood spots with FIA-MS/MS first, followed by the more specific ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) technique and, finally, the genetic confirmation via focused NGS.

Discussion

Genetically confirmed patients are set to undergo a follow-up protocol and are periodically evaluated to promptly start a specific treatment if and when the first signs of brain damage appear, as suggested by international guidelines. A specific disease monitoring protocol has been created based on literature data and personal direct experience.

Conclusion

The primary aim of this study was to develop a model able to improve the early diagnosis and subsequent follow-up and timely treatment of X-ALD.

Ethics

The study was approved by the local ethics committee. The research was conducted in the absence of any commercial or financial relationship that could be construed as a potential conflict of interest.

Could dietary erucic acid lower risk of brain tumors? An epidemiological look to Chinese population with implications for prevention and treatment

Erucic acid, an omega-9 monounsaturated fatty acid present in Brassicaceae plants (rapeseed and mustard oils) is highly consumed by the Chinese population and according to several global survey studies, its highest levels are encountered in the Chinese women's milk. Erucic acid is an activating ligand of the transcription factor PPARδ and an inhibitor of the transcriptional activity of PPARγ, which drive tumorigenesis of glioblastomas and medulloblastomas. In this theoretical review, we propose that erucic acid in diet may associate with the risk of brain tumors. High grade brain tumors including medulloblastomas in children and glioblastomas in adults have devastating consequences for human health and the latter tumors are practically incurable. CONCORD-3 epidemiological study recently published in 2021 revealed a low ratio of medulloblastomas in the pediatric age group and also a low ratio of glioblastomas in adults in the Chinese population. It is certain that such profound differences can not be attributed to a single genetic factor or a single nurture pattern. It is very likely that multiple hereditary, nutritional and environmental factors are responsible for these lower ratios; yet here we propose that erucic acid may be one of the contributing factors. If future epidemiological studies and animal models show antitumor activity of erucic acid regarding brain neoplasias, it can be utilized as a preventive strategy for populations possessing very high risks to develop brain tumors such as those harbouring hereditary syndromes increasing the vulnerability to develop such malignancies.

A Systemic Review for Ethnopharmacological Studies on Isatis indigotica Fortune: Bioactive Compounds and their Therapeutic Insights

Isatis indigotica Fortune is a biennial Chinese woad of the Cruciferae family. It is primarily cultivated in China, where it was a staple in indigo dye manufacture till the end of the 17th century. Today, I. indigotica is used primarily as a therapeutic herb in traditional Chinese medicine (TCM). The medicinal use of the plant is separated into its leaves (Da-Qing-Ye) and roots (Ban-Lan-Gen), whereas its aerial components can be processed into a dried bluish-spruce powder (Qing-Dai), following dehydration for long-term preservation. Over the past several decades, I. indigotica has been generally utilized for its heat-clearing effects and bodily detoxification in TCM, attributed to the presence of several classes of bioactive compounds, including organic acids, alkaloids, terpenoids, and flavonoids, as well as lignans, anthraquinones, glucosides, glucosinolates, sphingolipids, tetrapyrroles, and polysaccharides. This paper aims to delineate I. indigotica from its closely-related species (Isatis tinctoria and Isatis glauca) while highlighting the ethnomedicinal uses of I. indigotica from the perspectives of modern and traditional medicine. A systematic search of PubMed, Embase, PMC, Web of Science, and Google Scholar databases was done for articles on all aspects of the plant, emphasizing those analyzing the bioactivity of constituents of the plant. The various key bioactive compounds of I. indigotica that have been found to exhibit anti-inflammatory, antimicrobial, anticancer, and anti-allergic properties, along with the protective effects against neuronal injury and bone fracture, will be discussed. Collectively, the review hopes to draw attention to the therapeutic potential of I. indigotica not only as a TCM, but also as a potential source of bioactive compounds for disease management and treatment.

Gut Microbiome-Targeted Modulations Regulate Metabolic Profiles and Alleviate Altitude-Related Cardiac Hypertrophy in Rats

It is well known that humans physiologically or pathologically respond to high altitude, with these responses accompanied by alterations in the gut microbiome. To investigate whether gut microbiota modulation can alleviate high-altitude-related diseases, we administered probiotics, prebiotics, and synbiotics in rat model with altitude-related cardiac impairment after hypobaric hypoxia challenge and observed that all three treatments alleviated cardiac hypertrophy as measured by heart weight-to-body weight ratio and gene expression levels of biomarkers in heart tissue. The disruption of gut microbiota induced by hypobaric hypoxia was also ameliorated, especially for microbes of Ruminococcaceae and Lachnospiraceae families. Metabolome revealed that hypobaric hypoxia significantly altered the plasma short-chain fatty acids (SCFAs), bile acids (BAs), amino acids, neurotransmitters, and free fatty acids, but not the overall fecal SCFAs and BAs. The treatments were able to restore homeostasis of plasma amino acids and neurotransmitters to a certain degree, but not for the other measured metabolites. This study paves the way to further investigate the underlying mechanisms of gut microbiome in high-altitude related diseases and opens opportunity to target gut microbiome for therapeutic purpose. IMPORTANCE Evidence suggests that gut microbiome changes upon hypobaric hypoxia exposure; however, it remains elusive whether this microbiome change is a merely derivational reflection of host physiological alteration, or it synergizes to exacerbate high-altitude diseases. We intervened gut microbiome in the rat model of prolonged hypobaric hypoxia challenge and found that the intervention could alleviate the symptoms of pathological cardiac hypertrophy, gut microbial dysbiosis, and metabolic disruptions of certain metabolites in gut and plasma induced by hypobaric hypoxia. Our study suggests that gut microbiome may be a causative factor for high-altitude-related pathogenesis and a target for therapeutic intervention.

Characterization of uptake and metabolism of very long-chain fatty acids in peroxisome-deficient CHO cells

Fatty acids (FAs) longer than C20 are classified as very long-chain fatty acids (VLCFAs). Although biosynthesis and degradation of VLCFAs are important for the development and integrity of the myelin sheath, knowledge on the incorporation of extracellular VLCFAs into the cells is limited due to the experimental difficulty of solubilizing them. In this study, we found that a small amount of isopropanol solubilized VLCFAs in aqueous medium by facilitating the formation of the VLCFA/albumin complex. Using this solubilizing technique, we examined the role of the peroxisome in the uptake and metabolism of VLCFAs in Chinese hamster ovary (CHO) cells. When wild-type CHO cells were incubated with saturated VLCFAs (S-VLCFAs), such as C23:0 FA, C24:0 FA, and C26:0 FA, extensive uptake was observed. Most of the incorporated S-VLCFAs were oxidatively degraded without acylation into cellular lipids. In contrast, in peroxisome-deficient CHO cells uptake of S-VLCFAs was marginal and oxidative metabolism was not observed. Extensive uptake and acylation of monounsaturated (MU)-VLCFAs, such as C24:1 FA and C22:1 FA, were observed in both types of CHO cells. However, oxidative metabolism was evident only in wild-type cells. Similar manners of uptake and metabolism of S-VLCFAs and MU-VLCFAs were observed in IFRS1, a Schwan cell-derived cell line. These results indicate that peroxisome-deficient cells limit intracellular S-VLCFAs at a low level by halting uptake, and as a result, peroxisome-deficient cells almost completely lose the clearance ability of S-VLCFAs accumulated outside of the cells.

Metabolites Associated with Early Cognitive Changes Implicated in Alzheimer's Disease

BACKGROUND

Understanding metabolic mechanisms associated with cognitive changes preceding an Alzheimer's disease (AD) diagnosis could advance our understanding of AD progression and inform preventive methods.

OBJECTIVE

We investigated the metabolomics of the early changes in executive function and delayed recall, the earliest aspects of cognitive function to change in the course of AD development, in order to better understand mechanisms that could contribute to early stages and progression of this disease.

METHODS

This investigation used longitudinal plasma samples from the Wisconsin Registry for Alzheimer's Prevention (WRAP), a cohort of participants who were dementia free at enrollment and enriched with a parental history of AD. Metabolomic profiles were quantified for 2,324 fasting plasma samples among 1,200 participants, each with up to three study visits, which occurred every two years. Metabolites were individually tested for association with executive function and delayed recall trajectories across age.

RESULTS

Of 1,097 metabolites tested, levels of seven were associated with executive function trajectories, including an amino acid cysteine S-sulfate and three fatty acids, including erucate (22 : 1n9), while none were associated with delayed recall trajectories. Replication was attempted for four of these metabolites that were present in the Vietnam Era Twin Study of Aging (VETSA). Although none reached statistical significance, three of these associations showed consistent effectdirections.

CONCLUSION

Our results suggest potential metabolomic mechanisms that could contribute to the earliest signs of cognitive decline. In particular, fatty acids may be associated with cognition in a manner that is more complex than previously suspected.

A review on neuropharmacological role of erucic acid: an omega-9 fatty acid from edible oils

Neurodegenerative diseases (ND) are characterised by loss of neurons in the brain and spinal cord. For the normal functioning of the brain, divers group of fatty acids in the form of glycerophospholipids, glycerol ether lipids, cerebrosides, sulfatides, and gangliosides are essential. They are present abundantly in the nervous system and are actively involved in both the development and maintenance of the nervous system. A dietary deficiency of essential fatty acid during development results in hypomyelination state which affects various neuronal functions. Several studies suggested that age remains the primary risk factor for almost all neurodegenerative disorders. The potential contribution of these fatty acids in the progression of neurodegenerative disorders is indispensable. Erucic acid an omega 9 fatty acid, which is obtained from edible oils has proven to cause myocardial lipidosis, heart lesions and hepatic steatosis in animals therefore, its content in edible oils is restricted to certain levels by regulatory agencies. However, erucic acid in the form of a mixture with oleic acid is often used as a dietary treatment for the management of adrenoleukodystrophy without any cardiotoxicity. Our literature search revealed that, erucic acid reported to enhance cognitive function, interact with peroxisome proliferator activated receptors (PPARs), inhibit elastase and thrombin. In this review first we have attempted to describe the relationship between fatty acids and neurodegeneration followed by a description on the pharmacology of erucic acid. The overall purpose of this review is to analyse toxic and beneficial neuropharmacological effects of erucic acid.

PPARδ and its ligand erucic acid may act anti-tumoral, neuroprotective, and myelin protective in neuroblastoma, glioblastoma, and Parkinson's disease

In this review study, we focus on potential benefits of the transcription factor PPARδ and its ligand erucic acid (EA) in management of neuroectodermal tumors and Parkinson's Disease. PPARδ is a nuclear receptor and transcription factor that induces myelination, promotes oligodendroglial and neuronal differentiation, and possess anti-neuroinflammatory properties. While both pro-tumorigenic and anti-tumorigenic effects have been described for PPARδ, we propose that PPARδ may perform a predominantly anticancer role in tumors originating from the neuroectoderm. PPARδ ligand-activation via oleic acid and GW501516, or overexpression of PPARδ, elicits profound antitumor actions in neuroblastoma and melanoma. In glioblastomas, there is evidence indicating a differentiation failure of O2A (oligodendroglial-astrocytic biprogenitor) cells and it has been shown that EA reduced DNA synthesis in C6 rat glioblastoma spheroid cultures in clinically achievable concentrations. EA is a ω9 fatty acid which is being used in the treatment of adrenoleukodystrophy. EA is widely consumed in Asian countries via ingestion of cruciferous vegetables including mustard and rapeseed oil. EA also exerts antioxidant and anti-inflammatory activities. Recent studies of Parkinson's Disease (PD) have implicated demyelination, white matter pathology, oligodendroglial injury, and neural inflammation in the underlying pathophysiology. In the rotenone PD model in rats, PPARδ ligand GW501516 saves dopaminergic neurons during injury induced by chemical toxins and improves behavioral functioning in PD via alleviation of endoplasmic reticulum stress. PPARδ agonists also reduce the NLRP3 inflammasome-associated neural inflammation in the MPTP PD model in mice. Herein, we propose that PPARδ and its ligand EA highly deserve to be studied in animal models of neuroblastoma, glioblastoma, and PD.

X-linked adrenoleukodystrophy: Pathology, pathophysiology, diagnostic testing, newborn screening and therapies

Adrenoleukodystrophy (ALD) is a rare X‐linked disease caused by a mutation of the peroxisomal ABCD1 gene. This review summarizes our current understanding of the pathogenic cell‐ and tissue‐specific roles of lipid species in the context of experimental therapeutic strategies and provides an overview of critical historical developments, therapeutic trials and the advent of newborn screening in the USA. In ALD, very long‐chain fatty acid (VLCFA) chain length‐dependent dysregulation of endoplasmic reticulum stress and mitochondrial radical generating systems inducing cell death pathways has been shown, providing the rationale for therapeutic moiety‐specific VLCFA reduction and antioxidant strategies. The continuing increase in newborn screening programs and promising results from ongoing and recent therapeutic investigations provide hope for ALD.

Erucic acid, a nutritional PPARδ-ligand may influence Huntington's disease pathogenesis

Increasing recent evidence suggests a key role of oligodendroglial injury and demyelination in the pathophysiology of Huntington's Disease (HD) and the transcription factor PPARδ is critical for oligodendroglial regeneration and myelination. PPARδ directly involves in the pathogenesis of HD and treatment with a brain-permeable PPARδ-agonist (KD3010) alleviates its severity in mice. Erucic acid (EA) is also a PPARδ-ligand ω9 fatty acid which is highly consumed in Asian countries through ingesting cruciferous vegetables such as rapeseed (Brassica napus) and indian mustard (Brassica juncea). EA is also an ingredient of Lorenzo's oil employed in the medical treatment of adrenoleukodystrophy and can be converted to nervonic acid, a component of myelin. HD pathogenesis also involves oxidative and inflammatory injury and EA exerts antioxidative and antiinflammatory efficacies including inhibition of thrombin and elastase. Consumption of rapeseed, indian mustard, and Canola oils (containing EA) improves cognitive parameters in animal models, as well as treatment with pure EA. Moreover, erucamide, an endogenous EA-amide derivative regulating angiogenesis and water balance, exerts antidepressive and anxiolytic effects in mice. Hitherto, no study has investigated the therapeutic potential of EA in HD and we believe that it strongly merits to be studied in animal models of HD as a potential therapeutic.

X-linked Adrenoleukodystrophy: Pathology, Pathophysiology, Diagnostic Testing, Newborn Screening, and Therapies

Adrenoleukodystrophy (ALD) is a rare X-linked disease caused by a mutation of the peroxisomal ABCD1 gene. This review summarizes our current understanding of the pathogenic cell- and tissue-specific role of lipid species in the context of experimental therapeutic strategies and provides an overview of critical historical developments, therapeutic trials, and the advent of newborn screening in the United States. In ALD, very long chain fatty acid (VLCFA) chain-length-dependent dysregulation of endoplasmic reticulum stress and mitochondrial radical generating systems inducing cell death pathways has been shown, providing the rationale for therapeutic moiety-specific VLCFA reduction and antioxidant strategies. The continuing increase in newborn screening programs and promising results from ongoing and recent therapeutic investigations provide hope for ALD.

Changes in the content of fatty acids in CA1 and CA3 areas of the hippocampus of Krushinsky-Molodkina rats after single and fivefold audiogenic seizures

Audiogenic seizures (AS) are generalized seizures evoked by high frequency sounds. Since the hippocampus is involved in the generation and maintenance of seizures, the effect of AS on the composition and content of fatty acids in the CA1 and CA3 hippocampal areas of AS-susceptible Krushinsky-Molodkina (KM) rats on days 1, 3, and 14 after single and fivefold seizures were examined. The total content of all fatty acids in field СА1 was found to be lower compared with the control at all times of observation after both a single seizure or fivefold seizures. The total content of fatty acids in field СА3 decreased at all times of examination after a single seizure, whereas it remained unchanged on days 3 and 14 following five AS. The content of omega-3 fatty acids in both fields at all times of observation after a single seizure and fivefold AS did not significantly differ from that in intact animals. The absence of significant changes in the content of stearic and α-linolenic acids and a considerable decrease in the levels of palmitic, oleic, and eicosapentaenoic acids were common to both fields at all times after both a single seizure or fivefold AS. The changes in the content of fatty acids in the СА3 and СА1 fields of the brain of AS-susceptible rats indicate that fatty acids are involved in both the development of seizure activity and neuroprotective anticonvulsive processes.

Non-Neuronal Cells in the Hypothalamic Adaptation to Metabolic Signals

Although the brain is composed of numerous cell types, neurons have received the vast majority of attention in the attempt to understand how this organ functions. Neurons are indeed fundamental but, in order for them to function correctly, they rely on the surrounding "non-neuronal" cells. These different cell types, which include glia, epithelial cells, pericytes, and endothelia, supply essential substances to neurons, in addition to protecting them from dangerous substances and situations. Moreover, it is now clear that non-neuronal cells can also actively participate in determining neuronal signaling outcomes. Due to the increasing problem of obesity in industrialized countries, investigation of the central control of energy balance has greatly increased in attempts to identify new therapeutic targets. This has led to interesting advances in our understanding of how appetite and systemic metabolism are modulated by non-neuronal cells. For example, not only are nutrients and hormones transported into the brain by non-neuronal cells, but these cells can also metabolize these metabolic factors, thus modifying the signals reaching the neurons. The hypothalamus is the main integrating center of incoming metabolic and hormonal signals and interprets this information in order to control appetite and systemic metabolism. Hence, the factors transported and released from surrounding non-neuronal cells will undoubtedly influence metabolic homeostasis. This review focuses on what is known to date regarding the involvement of different cell types in the transport and metabolism of nutrients and hormones in the hypothalamus. The possible involvement of non-neuronal cells, in particular glial cells, in physiopathological outcomes of poor dietary habits and excess weight gain are also discussed.

Effect of Audiogenic Seizures on the Dynamics of Fatty Acid Composition of Hippocampal Dental Gyrus in Krushinsky-Molodkina Rats

Changes in the fatty acid composition of the hippocampal dentate gyrus in Krushinsky-Molodkina rats with hereditary predisposition to audiogenic seizures were studied in 1, 3, and 14 days after 1 or 5 seizures. Seizure activity changed the content of saturated and monounsaturated as well as polyunsaturated fatty acids at different terms after seizures. After seizures, the content of individual fatty acids changed in different directions. Similar shifts after 1 and 5 seizures were observed only for eicosapentaenoic acid at all observation terms. More pronounced changes in fatty acid composition were observed after 5 seizures. These results can be useful for the development of new approaches to correction of seizure activity.

A model-based approach to assess the exposure-response relationship of Lorenzo's oil in adrenoleukodystrophy

AIMS

X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder, most commonly affecting boys, associated with increased very long chain fatty acids (C26:0) in all tissues, causing cerebral demyelination and adrenocortical insufficiency. Certain monounsaturated long chain fatty acids including oleic and erucic acids, known as Lorenzo's oil (LO), lower plasma C26:0 levels. The aims of this study were to characterize the effect of LO administration on plasma C26:0 concentrations and to determine whether there is an association between plasma concentrations of erucic acid or C26:0 and the likelihood of developing brain MRI abnormalities in asymptomatic boys.

METHODS

Non-linear mixed effects modelling was performed on 2384 samples collected during an open label single arm trial. The subjects (n = 104) were administered LO daily at ~2-3 mg kg(-1) with a mean follow-up of 4.88 ± 2.76 years. The effect of erucic acid exposure on plasma C26:0 concentrations was characterized by an inhibitory fractional Emax model. A Weibull model was used to characterize the time-to-developing MRI abnormality.

RESULTS

The population estimate for the fractional maximum reduction of C26:0 plasma concentrations was 0.76 (bootstrap 95% CI 0.73, 0.793). Our time-to-event analyses showed that every mg l(-1) increase in time-weighted average of erucic acid and C26:0 plasma concentrations was, respectively, associated with a 3.7% reduction and a 753% increase in the hazard of developing MRI abnormality. However, the results were not significant (P = 0.5344, 0.1509, respectively).

CONCLUSIONS

LO administration significantly reduces the abnormally high plasma C26:0 concentrations in X-ALD patients. Further studies to evaluate the effect of LO on the likelihood of developing brain MRI abnormality are warranted.

The memory-enhancing effect of erucic acid on scopolamine-induced cognitive impairment in mice

Erucic acid is a monounsaturated omega-9 fatty acid isolated from the seed of Raphanus sativus L. that is known to normalize the accumulation of very long chain fatty acids in the brains of patients suffering from X-linked adrenoleukodystrophy. Here, we investigated whether erucic acid enhanced cognitive function or ameliorated scopolamine-induced memory impairment using the passive avoidance, Y-maze and Morris water maze tasks. Erucic acid (3mg/kg, p.o.) enhanced memory performance in normal naïve mice. In addition, erucic acid (3mg/kg, p.o.) ameliorated scopolamine-induced memory impairment, as assessed via the behavioral tasks. We then investigated the underlying mechanism of the memory-enhancing effect of erucic acid. The administration of erucic acid increased the phosphorylation levels of phosphatidylinositide 3-kinase (PI3K), protein kinase C zeta (PKCζ), extracellular signal-regulated kinase (ERK), cAMP response element-binding protein (CREB) and additional protein kinase B (Akt) in the hippocampus. These results suggest that erucic acid has an ameliorative effect in mice with scopolamine-induced memory deficits and that the effect of erucic acid is partially due to the activation of PI3K-PKCζ-ERK-CREB signaling as well as an increase in phosphorylated Akt in the hippocampus. Therefore, erucic acid may be a novel therapeutic agent for diseases associated with cognitive deficits, such as Alzheimer's disease.

Blood-brain barrier and brain fatty acid uptake: Role of arachidonic acid and PGE2

How do fatty acids enter the brain and what role, if any, do membrane and cytosolic fatty acid binding proteins have on facilitating this process? This is a fundamental question that many lipid neurochemists will freely admit they cannot answer in any kind of definitive manner. A study by Dalvi and colleagues in this issue of the Journal of Neurochemistry now adds to our knowledge in this field. Among other important observations, their experiments demonstrate that a physiological level of arachidonic acid (ARA), that could be associated with many different physiological and pathophysiological states, increases permeability in a model of the human blood brain barrier (BBB) in the absence of cytokines. This last point is very important as it suggests increases in BBB permeability may occur in situations other than those associated with increases in tumor necrosis factor a (TNFα) and interleukin1b (IL1β), giving additional options for developing drugs impacting BBB permeability.

α-Linolenic acid: nutraceutical, pharmacological and toxicological evaluation

α-Linolenic acid (ALA), a carboxylic acid with 18 carbons and three cis double bonds, is an essential fatty acid needed for human health and can be acquired via regular dietary intake of foods that contain ALA or dietary supplementation of foods high in ALA, for example flaxseed. ALA has been reported to have cardiovascular-protective, anti-cancer, neuro-protective, anti-osteoporotic, anti-inflammatory, and antioxidative effects. ALA is the precursor of longer chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but its beneficial effects on risk factors for cardiovascular diseases are still inconclusive. The recommended intake of ALA for cardiovascular health is reported to be 1.1-2.2g/day. Although there are limited toxicological data for ALA, no serious adverse effects have been reported. The evidence on an increased prostate cancer risk in association with dietary ALA is not conclusive. Based on the limited data currently available, it may be concluded that ALA may be beneficial as a nutraceutical/pharmaceutical candidate and is safe for use as a food ingredient.

Fatty acid biosynthesis from glutamate and glutamine is specifically induced in neuronal cells under hypoxia

Hypoxia is involved in many neuronal and non-neuronal diseases, and defining the mechanisms for tissue adaptation to hypoxia is critical for the understanding and treatment of these diseases. One mechanism for tissue adaptation to hypoxia is increased glutamine and/or glutamate (Gln/Glu) utilization. To address this mechanism, we determined incorporation of Gln/Glu and other lipogenic substrates into lipids and fatty acids in both primary neurons and a neuronal cell line under normoxic and hypoxic conditions and compared this to non-neuronal primary cells and non-neuronal cell lines. Incorporation of Gln/Glu into total lipids was dramatically and specifically increased under hypoxia in neuronal cells including both primary (2.0- and 3.0-fold for Gln and Glu, respectively) and immortalized cultures (3.5- and 8.0-fold for Gln and Glu, respectively), and 90% to 97% of this increase was accounted for by incorporation into fatty acids (FA) depending upon substrate and cell type. All other non-neuronal cells tested demonstrated decreased or unchanged FA synthesis from Gln/Glu under hypoxia. Consistent with these data, total FA mass was also increased in neuronal cells under hypoxia that was mainly accounted for by the increase in saturated and monounsaturated FA with carbon length from 14 to 24. Incorporation of FA synthesized from Gln/Glu was increased in all major lipid classes including cholesteryl esters, triacylglycerols, diacylglycerols, free FA, and phospholipids, with the highest rate of incorporation into triacylglycerols. These results indicate that increased FA biosynthesis from Gln/Glu followed by esterification may be a neuronal specific pathway for adaptation to hypoxia. We identified a novel neuronal specific pathway for adaptation to hypoxia through increased fatty acid biosynthesis from glutamine and glutamate (Gln/Glu) followed by esterification into lipids. All other non-neuronal cells tested demonstrated decreased or unchanged lipid synthesis from Gln/Glu under hypoxia. Incorporation of other lipogenic substrates into lipids was decreased under hypoxia in neuronal cells. We believe that this finding will provide a novel strategy for treatment of oxygen and energy deficient conditions in the neuronal system.

Unesterified docosahexaenoic acid is protective in neuroinflammation

Docosahexaenoic acid (22:6n-3) is the major brain n-3 polyunsaturated fatty acid and it is possible that docosahexaenoic acid is anti-inflammatory in the brain as it is known to be in other tissues. Using a combination of models including the fat-1 transgenic mouse, chronic dietary n-3 polyunsaturated fatty acid modulation in transgenic and wild-type mice, and acute direct brain infusion, we demonstrated that unesterified docosahexaenoic acid attenuates neuroinflammation initiated by intracerebroventricular lipopolysaccharide. Hippocampal neuroinflammation was assessed by gene expression and immunohistochemistry. Furthermore, docosahexaenoic acid protected against lipopolysaccharide-induced neuronal loss. Acute intracerebroventricular infusion of unesterified docosahexaenoic acid or its 12/15-lipoxygenase product and precursor to protectins and resolvins, 17S-hydroperoxy-docosahexaenoic acid, mimics anti-neuroinflammatory aspects of chronically increased unesterified docosahexaenoic acid. LC-MS/MS revealed that neuroprotectin D1 and several other docosahexaenoic acid-derived specialized pro-resolving mediators are present in the hippocampus. Acute intracerebroventricular infusion of 17S-hydroperoxy-docosahexaenoic acid increases hippocampal neuroprotectin D1 levels concomitant to attenuating neuroinflammation. These results show that unesterified docosahexaenoic acid is protective in a lipopolysaccharide-initiated mouse model of acute neuroinflammation, at least in part, via its conversion to specialized pro-resolving mediators; these docosahexaenoic acid stores may provide novel targets for the prevention and treatment(s) of neurological disorders with a neuroinflammatory component. Our study shows that chronically increased brain unesterified DHA levels, but not solely phospholipid DHA levels, attenuate neuroinflammation. Similar attenuations occur with acute increases in brain unesterified DHA or 17S-HpDHA levels, highlighting the importance of an available pool of precursor unesterified DHA for the production of enzymatically derived specialized pro-resolving mediators that are critical in the regulation of neuroinflammation.

A mixture of oleic, erucic and conjugated linoleic acids modulates cerebrospinal fluid inflammatory markers and improve somatosensorial evoked potential in X-linked adrenoleukodystrophy female carriers

X-linked adrenoleukodystrophy is a rare inherited demyelinating disorder characterized by an abnormal accumulation of very long chain fatty acids, mainly hexacosanoic acid (26:0), due to a mutation of the gene encoding for a peroxisomal membrane protein. The only available, and partially effective, therapeutic treatment consists of dietary intake of a 4:1 mixture of triolein and trierucin, called Lorenzo's oil (LO), targeted to inhibit the elongation of docosanoic acid (22:0) to 26:0. In this study we tested whether, besides inhibiting elongation, an enhancement of peroxisomal beta oxidation induced by conjugated linoleic acid (CLA), will improve somatosensory evoked potentials and modify inflammatory markers in adrenoleukodystrophy females carriers. We enrolled five heterozygous women. They received a mixture of LO (40 g/day) with CLA (5 g/day) for 2 months. The therapeutic efficacy was evaluated by the means of plasma levels of 26:0, 26:0/22:0 ratio, modification of cerebrospinal fluid (CSF) inflammatory markers and somatosensory evoked potentials. Changes of fatty acid profile, and in particular CLA incorporation, were also evaluated in CSF and plasma. The results showed that CLA promptly passes the blood brain barrier and the mixture was able to lower both 26:0 and 26:0/22:0 ratio in plasma. The mixture improved somatosensory evoked potentials, which were previously found unchanged or worsened with dietary LO alone, and reduced IL-6 levels in CSF in three out of five patients. Our data suggest that the synergic activity of CLA and LO, by enhancing peroxisomal beta-oxidation and preventing 26:0 formation, improves the somatosensory evoked potentials and reduces neuroinflammation.

Is subclinical adrenal failure in adrenoleukodystrophy/adrenomyeloneuropathy reversible?

BACKGROUND

X-linked adrenoleukodystrophy/adrenomieloneuropathy (ALD/AMN) is a progressive neurodegenerative disorder due to mutations in the ABCD1 gene encoding the ABC transporter ALDP. Mutations in ALDP impair peroxisomal β-oxidation of very long chain fatty acids (VLCFA), resulting in elevated levels of VLCFA in plasma, nervous system, and adrenals. Lorenzo's oil, combined with VLCFA- poor diet, normalizes plasma VLCFA within 1 month, but it does not prevent the progression of pre-existing neurological symptoms. No previous study analyzed the effect of Lorenzo's oil therapy on adrenal function.

AIM

To investigate short-term effects of Lorenzo's oil, combined with VLCFA- poor diet, on adrenal function of AMN patients with early subclinical signs of adrenal failure.

SUBJECTS AND METHODS

Seven AMN subjects underwent VLCFA-restricted diet combined with Lorenzo's oil (45 ml/day po), without steroid therapy, for 6 months.

RESULTS

All patients had elevated ACTH at baseline, and a significant reduction was evident after 6 months (median ACTH at baseline: 1300 pg/ml, range: 720- 2100; median ACTH at 6 months: 186 pg/ml, range: 109-320, p: 0.0156). Cortisol was normal both at baseline and after 6 months. VLCFA dropped in all patients during the 6- month follow-up, and no patient required glucocorticoid replacement therapy.

CONCLUSIONS

Adrenal insufficiency in ALD/AMN is probably due to a defective adrenal response to ACTH, related to VLCFA accumulation with progressive disruption of the adrenal cell membrane functions. In an early phase, Lorenzo's oil therapy may be able to improve VLCFA clearance and restore a normal ACTH receptor activity, and hypoadrenalism may be potentially reversible.

Fluorescent n-3 and n-6 very long chain polyunsaturated fatty acids: three-photon imaging in living cells expressing liver fatty acid-binding protein

Despite the considerable beneficial effects of n-3 and n-6 very long chain polyunsaturated fatty acids (VLC-PUFAs), very little is known about the factors that regulate their uptake and intracellular distribution in living cells. This issue was addressed in cells expressing liver-type fatty acid-binding protein (L-FABP) by real time multiphoton laser scanning microscopy of novel fluorescent VLC-PUFAs containing a conjugated tetraene fluorophore near the carboxyl group and natural methylene-interrupted n-3 or n-6 grouping. The fluorescent VLC-PUFAs mimicked many properties of their native nonfluorescent counterparts, including uptake, distribution, and metabolism in living cells. The unesterified fluorescent VLC-PUFAs distributed either equally in nuclei versus cytoplasm (22-carbon n-3 VLC-PUFA) or preferentially to cytoplasm (20-carbon n-3 and n-6 VLC-PUFAs). L-FABP bound fluorescent VLC-PUFA with affinity and specificity similar to their nonfluorescent natural counterparts. Regarding n-3 and n-6 VLC-PUFA, L-FABP expression enhanced uptake into the cell and cytoplasm, selectively altered the pattern of fluorescent n-6 and n-3 VLC-PUFA distribution in cytoplasm versus nuclei, and preferentially distributed fluorescent VLC-PUFA into nucleoplasm versus nuclear envelope, especially for the 22-carbon n-3 VLC-PUFA, correlating with its high binding by L-FABP. Multiphoton laser scanning microscopy data showed for the first time VLC-PUFA in nuclei of living cells and suggested a model, whereby L-FABP facilitated VLC-PUFA targeting to nuclei by enhancing VLC-PUFA uptake and distribution into the cytoplasm and nucleoplasm.

Brain arachidonic acid uptake and turnover: implications for signaling and bipolar disorder

PURPOSE OF REVIEW

Arachidonic acid was first detected in the brain in 1922. Although earlier work examined the role of arachidonic acid in growth and development, more recent advancements have elucidated roles for arachidonic acid in brain health and disease.

RECENT FINDINGS

In this review, we summarize evidence demonstrating that unesterified arachidonic acid in the plasma pool, which is supplied in part from adipose, is readily taken up and incorporated into brain phospholipids. By labeling plasma unesterified arachidonic acid, it is possible to trace the subsequent release of arachidonic acid from brain phospholipids upon neuroreceptor-mediated release by phospholipase A2 in response to drugs and neuroinflammation in rodents. With the synthesis of 11C labeled fatty acids, brain arachidonic acid signaling can now be measured in humans with position emission tomography. Arachidonic acid signals are known to regulate important biological functions, including neuroinflammation and excitotoxicity, and we focus on how the brain arachidonic acid cascade is a common target of drugs used to treat bipolar disorder (e.g. lithium, carbamazepine and valproate).

SUMMARY

A better understanding of the regulation of arachidonic acid uptake into the brain and the brain arachidonic acid cascade could lead to new imaging techniques and the identification of novel therapeutic targets in excitotoxicity, neuroinflammation and bipolar disorder.

The very low density lipoprotein receptor is not necessary for maintaining brain polyunsaturated fatty acid concentrations

Polyunsaturated fatty acids (PUFA), especially docosahexaenoic and arachidonic acids, as well as cholesterol are important for neural development and maintaining brain function. However, in contrast to cholesterol, the brain is unable to synthesize the required amounts of these PUFA de novo and requires a constant supply from plasma. Suggested pools of uptake include plasma unesterified PUFA or the uptake of PUFA-containing lipoproteins via lipoprotein receptors into endothelial cells of the blood brain barrier. Our study tested whether the very low density lipoprotein receptor (VLDLr) is necessary for maintaining brain PUFA and cholesterol concentrations. Moreover, since VLDLr knockout (VLDLr(-/-)) mice have been reported to have behavioural deficits, this study asked the question whether altered brain PUFA and cholesterol concentrations might be related to these deficits. VLDLr(-/-) and wild-type mice had ad libitum access to chow. At 7 weeks of age the mice were sacrificed, and the cortex, cerebellum, hippocampus, and the remainder of the brain were isolated for total fatty acid and cholesterol analyses. There were no differences in total lipid PUFA or cholesterol concentrations in any of the four brain regions between VLDLr(-/-) and wild-type mice. These findings demonstrate that the VLDLr is not necessary for maintaining brain PUFA concentrations and suggest that other mechanisms to transport PUFA into the brain must exist.

Molecular cloning and characterization of a KCS gene from Cardamine graeca and its heterologous expression in Brassica oilseeds to engineer high nervonic acid oils for potential medical and industrial use

Nervonic acid 24:1 Delta15 (cis-tetracos-15-enoic acid) is a very long-chain monounsaturated fatty acid and exists in nature as an elongation product of oleic acid. There is an increasing interest in production of high nervonic acid oils for pharmaceutical, nutraceutical and industrial applications. Using a polymerase chain reaction approach, we have isolated a gene from Cardamine graeca L., which encodes a 3-ketoacyl-CoA synthase (KCS), the first component of the elongation complex involved in synthesis of nervonic acid. Expression of the Cardamine KCS in yeast resulted in biosynthesis of nervonic acid, which is not normally present in yeast cells. We transformed Arabidopsis and Brassica carinata with the Cardamine KCS under the control of the seed-specific promoter, napin. The T(3) generations of transgenic Arabidopsis and B. carinata plants expressing the Cardamine KCS showed that seed-specific expression resulted in relatively large comparative increases in nervonic acid proportions in Arabidopsis seed oil, and 15-fold increase in nervonic acid proportions in B. carinata seed oil. The highest nervonic acid level in transgenic B. carinata lines reached 44%, with only 6% of residual erucic acid. In contrast, similar transgenic expression of the Cardamine KCS in high erucic B. napus resulted in 30% nervonic acid but with 20% residual erucic acid. Experiments using the Lunaria KCS gene gave results similar to the latter. In both cases, the erucic acid content is too high for human or animal consumption. Thus, the Cardamine KCS: B. carinata high nervonic/highly reduced erucic transgenic seed oils will be the most suitable for testing in pharmaceutical/nutraceutical applications to improve human and animal health.

Brain phospholipid arachidonic acid half-lives are not altered following 15 weeks of N-3 polyunsaturated fatty acid adequate or deprived diet

Previous studies have infused radiolabeled arachidonic acid (AA) into rat brains and followed AA esterification into phospholipids for up to 24 h; however, the half-life of AA in rat brain phospholipids is unknown. Eighteen day old rats were fed either an n-3 PUFA adequate or deprived diet for 15 weeks. Following the 15 weeks, 40 microCi of [(3)H] AA was injected intracerebroventricularly into the right lateral ventricle using stereotaxic surgery and returned to their dietary treatment. From 4-120 days after [(3)H] AA administration, brains were collected for chemical analyses. The half-life of AA in rat brain phospholipids was 44 +/- 4 days for the n-3 PUFA adequate group and 46 +/- 4 days for the n-3 PUFA deprived group, which closely approximates the predicted half-life previously reported, based on the rate of entry from the plasma unesterified pool, suggesting the plasma unesterified pool is a major contributor to brain uptake of AA. Furthermore, unlike a previous report in which the half-life of brain phospholipid docosahexaenoic acid (DHA) was increased in n-3 PUFA deprived rats, n-3 PUFA deprivation did not significantly alter the AA half-life, suggesting different mechanisms exist to maintain brain concentrations of AA and DHA.

Alpha-linolenic acid and its conversion to longer chain n-3 fatty acids: benefits for human health and a role in maintaining tissue n-3 fatty acid levels

There is little doubt regarding the essential nature of alpha-linolenic acid (ALA), yet the capacity of dietary ALA to maintain adequate tissue levels of long chain n-3 fatty acids remains quite controversial. This simple point remains highly debated despite evidence that removal of dietary ALA promotes n-3 fatty acid inadequacy, including that of docosahexaenoic acid (DHA), and that many experiments demonstrate that dietary inclusion of ALA raises n-3 tissue fatty acid content, including DHA. Herein we propose, based upon our previous work and that of others, that ALA is elongated and desaturated in a tissue-dependent manner. One important concept is to recognize that ALA, like many other fatty acids, rapidly undergoes beta-oxidation and that the carbons are conserved and reused for synthesis of other products including cholesterol and fatty acids. This process and the differences between utilization of dietary DHA or liver-derived DHA as compared to ALA have led to the dogma that ALA is not a useful fatty acid for maintaining tissue long chain n-3 fatty acids, including DHA. Herein, we propose that indeed dietary ALA is a crucial dietary source of n-3 fatty acids and its dietary inclusion is critical for maintaining tissue long chain n-3 levels.

Increase in nervonic acid content in transformed yeast and transgenic plants by introduction of a Lunaria annua L. 3-ketoacyl-CoA synthase (KCS) gene

Nervonic acid is a Very Long-Chain Monounsaturated Fatty Acid (VLCMFA), 24:1 Delta15 (cis-tetracos-15-enoic acid) found in the seed oils of Lunaria annua, borage, hemp, Acer (Purpleblow maple) and Tropaeolum speciosum (Flame flower). However, of these, only the "money plant" (Lunaria annua L.) has been studied and grown sparingly for future development as a niche crop and the outlook has been disappointing. Therefore, our goal was to isolate and characterize strategic new genes for high nervonic acid production in Brassica oilseed crops. To this end, we have isolated a VLCMFA-utilizing 3-Keto-Acyl-CoA Synthase (KCS; fatty acid elongase; EC 2.3.1.86) gene from Lunaria annua and functionally expressed it in yeast, with the recombinant KCS protein able to catalyze the synthesis of several VLCMFAs, including nervonic acid. Seed-specific expression of the Lunaria KCS in Arabidopsis resulted in a 30-fold increase in nervonic acid proportions in seed oils, compared to the very low quantities found in the wild-type. Similar transgenic experiments using B. carinata as the host resulted in a 7-10 fold increase in seed oil nervonic acid proportions. KCS enzyme activity assays indicated that upon using (14)C-22:1-CoA as substrate, the KCS activity from developing seeds of transgenic B. carinata was 20-30-fold higher than the low erucoyl-elongation activity exhibited by wild type control plants. There was a very good correlation between the Lun KCS transcript intensity and the resultant 22:1-CoA KCS activity in developing seed. The highest nervonic acid level in transgenic B. carinata expressing the Lunaria KCS reached 30%, compared to 2.8% in wild type plant. In addition, the erucic acid proportions in these transgenic lines were considerably lower than that found in native Lunaria oil. These results show the functional utility of the Lunaria KCS in engineering new sources of high nervonate/reduced erucic oils in the Brassicaceae.

Rapid beta-oxidation of eicosapentaenoic acid in mouse brain: an in situ study

Analyses of brain phospholipid fatty acid profiles reveal a selective deficiency and enrichment in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. In order to account for this difference in brain fatty acid levels, we hypothesized that EPA is more rapidly beta-oxidized upon its entry into the brain. Wild-type C57BL/6 mice were perfused with either (14)C-EPA or (14)C-DHA via in situ cerebral perfusion for 40s, followed by a bicarbonate buffer to wash out the residual radiolabeled polyunsaturated fatty acid (PUFA) in the capillaries. (14)C-PUFA-perfused brains were extracted for chemical analyses of neutral lipid and phospholipid fatty acids. Based on the radioactivity in aqueous, total lipid, neutral lipid and phospholipid fractions, volume of distribution (V(D), microl/g) was calculated. The V(D) between (14)C-EPA- and (14)C-DHA-perfused samples was not statistically different for total lipid, neutral lipids or total phospholipids. However, the V(D) of (14)C-EPA in the aqueous fraction was 2.5 times higher than that of (14)C-DHA (p=0.025), suggesting a more extensive beta-oxidation than DHA. Furthermore, radiolabeled palmitoleic acid, a fatty acid that can be synthesized de novo, was detected in brain phospholipids from (14)C-EPA but not from (14)C-DHA-perfused mice suggesting that beta-oxidation products of EPA were recycled into endogenous fatty acid biosynthetic pathways. These findings suggest that low levels of EPA in brain phospholipids compared to DHA may be the result of its rapid beta-oxidation upon uptake by the brain.

Regulation of brain polyunsaturated fatty acid uptake and turnover

The brain is particularly enriched in glycerophospholipids with either arachidonic or docosahexaenoic acid esterified in the stereospecifically numbered-2 position. In this paper, we review how combining a kinetic approach to study the uptake and turnover of arachidonic and docosahexaenoic acids within brain phospholipids of unanesthetized rats, along with chronic administration of antimanic drugs (lithium, valproate and carbamazepine), have advanced our understanding of how polyunsaturated fatty acids (PUFA) enter the brain, and the mechanisms that regulate their turnover within brain phospholipids. The incorporation rates of arachidonic and docosahexaenoic acid from the plasma unesterified pool into brain phospholipids closely approximate independent measures of their consumption rates by the brain, suggesting this is quantitatively the major pool for uptake of these PUFA. Antimanic drugs (lithium and carbamazepine) that downregulate the activity of the calcium-dependent cytosolic phospholipase A(2) (cPLA(2)) transcription factor AP-2, and in turn the expression and activity of cPLA(2,) lead to a selective downregulation in brain arachidonic acid turnover. Furthermore, targeting arachidonoyl-CoA formation via ordered, non-competitive inhibition of an acyl-CoA synthetase with valproate also selectively decreases brain arachidonic acid turnover. Drugs that increase brain cPLA(2) activity (N-methyl-d-aspartic acid and fluoxetine) are correlated with increased turnover of arachidonic acid in brain phospholipids. Altered PUFA metabolism has been implicated in several neurological disorders, including bipolar disorder and Alzheimer's disease. Identifying the enzymes that regulated brain PUFA metabolism could lead to new therapeutic approaches for these disorders.

The low density lipoprotein receptor is not necessary for maintaining mouse brain polyunsaturated fatty acid concentrations

The brain cannot synthesize n-6 or n-3 PUFAs de novo and requires their transport from the blood. Two models of brain fatty acid uptake have been proposed. One requires the passive diffusion of unesterified fatty acids through endothelial cells of the blood-brain barrier, and the other requires the uptake of lipoproteins via a lipoprotein receptor on the luminal membrane of endothelial cells. This study tested whether the low density lipoprotein receptor (LDLr) is necessary for maintaining brain PUFA concentrations. Because the cortex has a low basal expression of LDLr and the anterior brain stem has a relatively high expression, we analyzed these regions separately. LDLr knockout (LDLr(-/-)) and wild-type mice consumed an AIN-93G diet ad libitum until 7 weeks of age. After microwaving, the cortex and anterior brain stem (pons and medulla) were isolated for phospholipid fatty acid analyses. There were no differences in phosphatidylserine, phosphatidylinositol, ethanolamine, or choline glycerophospholipid esterified PUFA or saturated or monounsaturated fatty acid concentrations in the cortex or brain stem between LDLr(-/-) and wild-type mice. These findings demonstrate that the LDLr is not necessary for maintaining brain PUFA concentrations and suggest that other mechanisms to transport PUFAs into the brain must exist.

“Lorenzo’s Oil” Therapy for X-linked Adrenoleukodystrophy: Rationale and Current Assessment of Efficacy

X-linked adrenoleukodystrophy (X-ALD) is a genetic disorder that damages the nervous system and is associated with the accumulation of saturated very long chain fatty acids (SVLCFA). Oral administration of "Lorenzo's oil" (LO), a 4:1 mixture of glyceryl trioleate and glyceryl trierucate, normalizes the SVLCFA levels in plasma, but its clinical efficacy and the clinical indications for its use have been controversial for more than 15 years. We review the biochemical effects of LO administration and the rationale for its use and present a current appraisal of its capacity to reduce the risk for the childhood cerebral phenotype when administered to asymptomatic boys and to slow progression of adrenomyeloneuropathy in patients without cerebral involvement. We also present current efforts to provide definitive evaluation of its clinical efficacy and discuss its possible role in the new therapeutic opportunities that will arise if newborn screening for X-ALD is validated and implemented.