Gut microbiota modulation accounts for the neuroprotective properties of anthocyanins.

High-fat (HF) diets are thought to disrupt the profile of the gut microbiota in a manner that may contribute to the neuroinflammation and neurobehavioral changes observed in obesity. Accordingly, we hypothesize that by preventing HF-diet induced dysbiosis it is possible to prevent neuroinflammation and the consequent neurological disorders. Anthocyanins are flavonoids found in berries that exhibit anti-neuroinflammatory properties in the context of obesity. Here, we demonstrate that the blackberry anthocyanin-rich extract (BE) can modulate gut microbiota composition and counteract some of the features of HF-diet induced dysbiosis. In addition, we show that the modifications in gut microbial environment are partially linked with the anti-neuroinflammatory properties of BE. Through fecal metabolome analysis, we unravel the mechanism by which BE participates in the bilateral communication between the gut and the brain. BE alters host tryptophan metabolism, increasing the production of the neuroprotective metabolite kynurenic acid. These findings strongly suggest that dietary manipulation of the gut microbiota with anthocyanins can attenuate the neurologic complications of obesity, thus expanding the classification of psychobiotics to anthocyanins.

Effect of chronic consumption of blackberry extract on high-fat induced obesity in rats and its correlation with metabolic and brain outcomes.

Flavonoids have been presented as potential protectors against metabolic and cognitive dysfunction. However, mechanisms underlying these 'claims' have not been sufficiently explored. To analyse the effect of long-term supplementation with blackberry extract (BE) in the context of a high-fat or a standard diet, Wistar rats were divided into 4 groups (n = 6) fed with a standard or a high-fat diet, with or without BE supplementation at 25 mg per kg body weight per day. A high-fat diet significantly impaired glucose tolerance and increased body weight, caloric ingestion, very-low-density lipoprotein, triglycerides and cholesterol. Furthermore, it was observed that a high-fat diet increased dopamine content in the prefrontal cortex and decreased brain derived neurotrophic factor (BDNF) levels both in the prefrontal cortex and in plasma. BE supplementation only affected some of these aspects. BE slightly improved glucose metabolism and significantly decreased levels of lactate, independent of diet. BE decreased levels of BDNF and also interacted with the dopaminergic system, increasing dopamine turnover in the striatum, and reverting dopamine content induced by a high-fat diet in the prefrontal cortex. This study shows that, despite some particular benefits of anthocyanin supplementation, some long-term effects may not be desirable and further studies are needed to optimize ingestion conditions.

The impact of chronic blackberry intake on the neuroinflammatory status of rats fed a standard or high-fat diet.

Neuroinflammation has been suggested as a central mediator of central nervous system dysfunction, including in dementia and neurodegenerative disease. Flavonoids have emerged as promising candidates for the prevention of neurodegenerative diseases and are thought to be capable of antiinflammatory effects in the brain. In the present study, the impact of a chronic intake of an anthocyanin extract from blackberry (BE) on brain inflammatory status in the presence or absence of a high-fat diet was investigated. Following intake of the dietary regimes for 17 weeks neuroinflammatory status in Wistar rat cortex, hippocampus and plasma were assessed using cytokine antibody arrays. In the cortex, intake of the high-fat diet resulted in an increase of at least 4-fold, in expression of the cytokine-induced neutrophil chemoattractant CINC-3, the ciliary neurotrophic factor CNTF, the platelet-derived growth factor PDGF-AA, IL-10, the tissue inhibitor of metalloproteinase TIMP-1 and the receptor for advanced glycation end products RAGE. BE intake partially decreased the expression of these mediators in the high-fat challenged brain. In standard-fed animals, BE intake significantly increased cortical levels of fractalkine, PDGF-AA, activin, the vascular endothelial growth factor VEGF and agrin expression, suggesting effects as neuronal growth and synaptic connection modulators. In hippocampus, BE modulates fractalkine and the thymus chemokine TCK-1 expression independently of diet intake and, only in standard diet, increased PDGF-AA. Exploring effects of anthocyanins on fractalkine transcription using the neuronal cell line SH-SY5Y suggested that other cell types may be involved in this effect. This is the first evidence, in in vivo model, that blackberry extract intake may be capable of preventing the detrimental effects of neuroinflammation in a high-fat challenged brain. Also, fractalkine and TCK-1 expression may be specific targets of anthocyanins and their metabolites on neuroinflammation.

Excess perigestational folic acid exposure induces metabolic dysfunction in post-natal life.

The aim of this study was to understand whether high folic acid (HFA) exposure during the perigestational period induces metabolic dysfunction in the offspring, later in life. To do this, female Sprague-Dawley rats (G0) were administered a dose of folic acid (FA) recommended for pregnancy (control, C, 2 mg FA/kg of diet, n=5) or a high dose of FA (HFA, 40 mg FA/kg of diet, n=5). Supplementation began at mating and lasted throughout pregnancy and lactation. Body weight and food and fluid intake were monitored in G0 and their offspring (G1) till G1 were 13 months of age. Metabolic blood profiles were assessed in G1 at 3 and 13 months of age (3M and 13M respectively). Both G0 and G1 HFA females had increased body weight gain when compared with controls, particularly 22 (G0) and 10 (G1) weeks after FA supplementation had been stopped. G1 female offspring of HFA mothers had increased glycemia at 3M, and both female and male G1 offspring of HFA mothers had decreased glucose tolerance at 13M, when compared with matched controls. At 13M, G1 female offspring of HFA mothers had increased insulin and decreased adiponectin levels, and G1 male offspring of HFA mothers had increased levels of leptin, when compared with matched controls. In addition, feeding of fructose to adult offspring revealed that perigestational exposure to HFA renders female progeny more susceptible to developing metabolic unbalance upon such a challenge. The results of this work indicate that perigestational HFA exposure the affects long-term metabolic phenotype of the offspring, predisposing them to an insulin-resistant state.

Optimization and validation of organochlorine compounds in adipose tissue by SPE-gas chromatography.

Scientific evidence has shown an association between organochlorine compounds (OCC) exposure and human health hazards. Concerning this, OCC detection in human adipose samples has to be considered a public health priority. This study evaluated the efficacy of various solid-phase extraction (SPE) and cleanup methods for OCC determination in human adipose tissue. Octadecylsilyl endcapped (C18-E), benzenesulfonic acid modified silica cation exchanger (SA), poly(styrene-divinylbenzene (EN) and EN/RP18 SPE sorbents were evaluated. The relative sample cleanup provided by these SPE columns was evaluated using gas chromatography with electron capture detection (GC-ECD). The C18-E columns with strong homogenization were found to provide the most effective cleanup, removing the greatest amount of interfering substance, and simultaneously ensuring good analyte recoveries higher than 70%. Recoveries > 70% with standard deviations (SD) < 15% were obtained for all compounds under the selected conditions. Method detection limits were in the 0.003-0.009 mg/kg range. The positive samples were confirmed by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The highest percentage found of the OCC in real samples corresponded to HCB, o,p'-DDT and methoxychlor, which were detected in 80 and 95% of samples analyzed respectively.

Maitake (D fraction) mushroom extract induces apoptosis in breast cancer cells by BAK-1 gene activation.

For many years mushrooms have been used empirically in traditional medicine to treat several diseases. Study of the maitake mushroom, with its immunomodulatory and antitumoral properties, has led to the isolation of several bioactive compounds. One of these, D fraction, is known to reduce tumor cell viability. This study examined the effect of isolated D fraction on viability and apoptosis of human breast cancer cells (MCF7). These cells were treated with maitake (D fraction) extract at 18 µg/mL, 36 µg/mL, 91 µg/mL, 183 µg/mL, or 367 µg/mL or were left untreated (control) for 24 hours. MCF7 incubation with the maitake extract resulted in decreased cell viability [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay] in a dose-dependent manner. Apoptosis was statistically significantly increased in a dose-dependent manner at every concentration tested (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling assay). Upon incubation with D fraction, a microarray assay revealed upregulation of BAK-1 and cytochrome c transcripts, 2 proteins directly involved in the apoptotic pathway. Reverse transcriptase polymerase chain reaction studies confirmed these findings; BAK-1 was one of most overexpressed gene, as observed by microarray assay. These findings confirm the apoptotic effect of maitake D fraction in breast cancer cells and further highlight the involvement of cytochrome c release to the cytoplasm. Cytoplasmic release of cytochrome c, another player in the apoptotic pathway, was also increased after incubation with D fraction in a dose-dependent manner. This finding indicates that the effect of this compound involves mitochondrial dysfunction. The identification of the molecular mechanisms by which D fraction exerts its effects is crucial for the development of preventive and therapeutic strategies for cancer.