The brain is highly enriched with fatty acids. These include the polyunsaturated fatty acids (PUFAs) arachidonic acid and docosahexaenoic acid, which are largely esterified to the phospholipid cell membrane. Once PUFAs are released from the membrane, they can participate in signal transduction, either directly or after enzymatic conversion to a variety of bioactive derivatives ('mediators'). PUFAs and their mediators regulate several processes within the brain, such as neurotransmission, cell survival and neuroinflammation, and thereby mood and cognition. PUFA levels and the signalling pathways that they regulate are altered in various neurological disorders, including Alzheimer's disease and major depression. Diet and drugs targeting PUFAs may lead to novel therapeutic approaches for the prevention and treatment of brain disorders.

Neuroinflammation is proposed as one of the mechanisms by which Alzheimer’s disease pathology, including amyloid-β plaques, leads to neuronal death and dysfunction. Increases in the expression of markers of microglia, the main neuroinmmune cell, are widely reported in brains from patients with Alzheimer’s disease, but the literature has not yet been systematically reviewed to determine whether this is a consistent pathological feature. A systematic search was conducted in Medline, Embase and PsychINFO for articles published up to 23 February 2017. Papers were included if they quantitatively compared microglia markers in post-mortem brain samples from patients with Alzheimer’s disease and aged controls without neurological disease. A total of 113 relevant articles were identified. Consistent increases in markers related to activation, such as major histocompatibility complex II (36/43 studies) and cluster of differentiation 68 (17/21 studies), were identified relative to nonneurological aged controls, whereas other common markers that stain both resting and activated microglia, such as ionized calcium-binding adaptor molecule 1 (10/20 studies) and cluster of differentiation 11b (2/5 studies), were not consistently elevated. Studies of ionized calcium-binding adaptor molecule 1 that used cell counts almost uniformly identified no difference relative to control, indicating that increases in activation occurred without an expansion of the total number of microglia. White matter and cerebellum appeared to be more resistant to these increases than other brain regions. Nine studies were identified that included high pathology controls, patients who remained free of dementia despite Alzheimer’s disease pathology. The majority (5/9) of these studies reported higher levels of microglial markers in Alzheimer’s disease relative to controls, suggesting that these increases are not solely a consequence of Alzheimer’s disease pathology. These results show that increased markers of microglia are a consistent feature of Alzheimer’s disease, though this seems to be driven primarily by increases in activation-associated markers, as opposed to markers of all microglia.

Schizophrenia is a psychiatric disorder which has a lifetime prevalence of ~1%. Multiple candidate mechanisms have been proposed in the pathogenesis of schizophrenia. One such mechanism is the involvement of neuroinflammation. Clinical studies, including neuroimaging, peripheral biomarkers and randomized control trials, have suggested the presence of neuroinflammation in schizophrenia. Many studies have also measured markers of neuroinflammation in postmortem brain samples from schizophrenia patients. The objective of this study was to conduct a systematic search of the literature on neuroinflammation in postmortem brains of schizophrenia patients indexed in MEDLINE, Embase and PsycINFO. Databases were searched up until 20th March 2016 for articles published on postmortem brains in schizophrenia evaluating microglia, astrocytes, glia, cytokines, the arachidonic cascade, substance P and other markers of neuroinflammation. Two independent reviewers extracted the data. Out of 5385 articles yielded by the search, 119 articles were identified that measured neuroinflammatory markers in schizophrenic postmortem brains. Glial fibrillary acidic protein expression was elevated, lower or unchanged in 6, 6 and 21 studies, respectively, and similar results were obtained for glial cell densities. On the other hand, microglial markers were increased, lower or unchanged in schizophrenia in 11, 3 and 8 studies, respectively. Results were variable across all other markers, but SERPINA3 and IFITM were consistently increased in 4 and 5 studies, respectively. Despite the variability, some studies evaluating neuroinflammation in postmortem brains in schizophrenia suggest an increase in microglial activity and other markers such as SERPINA3 and IFITM. Variability across studies is partially explained by multiple factors including brain region evaluated, source of the brain, diagnosis, age at time of death, age of onset and the presence of suicide victims in the cohort.

Aims/hypothesis Dietary non-oil-seed pulses (chickpeas, beans, peas, lentils, etc.) are a good source of slowly digestible carbohydrate, fibre and vegetable protein and a valuable means of lowering the glycaemic-index (GI) of the diet. To assess the evidence that dietary pulses may benefit glycaemic control, we conducted a systematic review and meta-analysis of randomised controlled experimental trials investigating the effect of pulses, alone or as part of low-GI or high-fibre diets, on markers of glycaemic control in people with and without diabetes. Methods We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Library for relevant controlled trials of ≥7 days. Two independent reviewers (A. Esfahani and J. M. W. Wong) extracted information on study design, participants, treatments and outcomes. Data were pooled using the generic inverse variance method and expressed as standardised mean differences (SMD) with 95% CIs. Heterogeneity was assessed by χ 2 and quantified by I 2 . Meta-regression models identified independent predictors of effects. Results A total of 41 trials (39 reports) were included. Pulses alone (11 trials) lowered fasting blood glucose (FBG) (−0.82, 95% CI −1.36 to −0.27) and insulin (−0.49, 95%

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 PUFA modulation in transgenic and wildtype 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. Further, 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. LCMS/MS revealed that neuroprotectin D1 and several other docosahexaenoic acid-derived specialized pro-resolving mediators are present in the hippocampus. Acute icv infusion of 17S-hydroperoxydocosahexaenoic 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.

Classically, polyunsaturated fatty acids (PUFA) were largely thought to be relatively inert structural components of brain, largely important for the formation of cellular membranes. Over the past 10 years, a host of bioactive lipid mediators that are enzymatically derived from arachidonic acid, the main n-6 PUFA, and docosahexaenoic acid, the main n-3 PUFA in the brain, known to regulate peripheral immune function, have been detected in the brain and shown to regulate microglia activation. Recent advances have focused on how PUFA regulate the molecular signaling of microglia, especially in the context of neuroinflammation and behavior. Several active drugs regulate brain lipid signaling and provide proof of concept for targeting the brain. Because brain lipid metabolism relies on a complex integration of diet, peripheral metabolism, including the liver and blood, which supply the brain with PUFAs that can be altered by genetics, sex, and aging, there are many pathways that can be disrupted, leading to altered brain lipid homeostasis. Brain lipid signaling pathways are altered in neurologic disorders and may be viable targets for the development of novel therapeutics. In this study, we discuss in particular how n-3 PUFAs and their metabolites regulate microglia phenotype and function to exert their anti-inflammatory and proresolving activities in the brain.

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OBJECTIVE -To determine whether addition of Salba (Salvia hispanica L.), a novel whole grain that is rich in fiber, ␣-linolenic acid (ALA), and minerals to conventional treatment is associated with improvement in major and emerging cardiovascular risk factors in individuals with type 2 diabetes.RESEARCH DESIGN AND METHODS -Using a single-blind cross-over design, subjects were randomly assigned to receive either 37 Ϯ 4 g/day of Salba or wheat bran for 12 weeks while maintaining their conventional diabetes therapies. Twenty well-controlled subjects with type 2 diabetes (11 men and 9 women, aged 64 Ϯ 8 years, BMI 28 Ϯ 4 kg/m 2 , and A1C 6.8 Ϯ 0.9%) completed the study. This study was set in the outpatient clinic of the Risk Factor Modification Center, St. Michael's Hospital, Toronto, Canada.RESULTS -Compared with the control treatment, Salba reduced systolic blood pressure (SBP) by 6.3 Ϯ 4 mmHg (P Ͻ 0.001), high-sensitivity C-reactive protein (hs-CRP) (mg/l) by 40 Ϯ 1.6% (P ϭ 0.04), and vonWillebrand factor (vWF) by 21 Ϯ 0.3% (P ϭ 0.03), with significant decreases in A1C and fibrinogen in relation to the Salba baseline but not with the control treatment. There were no changes in safety parameters including liver, kidney and hemostatic function, or body weight. Both plasma ALA and eicosapentaenoic polyunsaturated fatty acid levels were increased twofold (P Ͻ 0.05) while consuming Salba.CONCLUSIONS -Long-term supplementation with Salba attenuated a major cardiovascular risk factor (SBP) and emerging factors (hs-CRP and vWF) safely beyond conventional therapy, while maintaining good glycemic and lipid control in people with well-controlled type 2 diabetes.