Effects of Ketone Bodies on Brain Metabolism and Function in Neurodegenerative Diseases

Under normal physiological conditions the brain primarily utilizes glucose for ATP generation. However, in situations where glucose is sparse, e.g., during prolonged fasting, ketone bodies become an important energy source for the brain. The brain’s utilization of ketones seems to depend mainly on the concentration in the blood, thus many dietary approaches such as ketogenic diets, ingestion of ketogenic medium-chain fatty acids or exogenous ketones, facilitate significant changes in the brain’s metabolism. Therefore, these approaches may ameliorate the energy crisis in neurodegenerative diseases, which are characterized by a deterioration of the brain’s glucose metabolism, providing a therapeutic advantage in these diseases. Most clinical studies examining the neuroprotective role of ketone bodies have been conducted in patients with Alzheimer’s disease, where brain imaging studies support the notion of enhancing brain energy metabolism with ketones. Likewise, a few studies show modest functional improvements in patients with Parkinson’s disease and cognitive benefits in patients with—or at risk of—Alzheimer’s disease after ketogenic interventions. Here, we summarize current knowledge on how ketogenic interventions support brain metabolism and discuss the therapeutic role of ketones in neurodegenerative disease, emphasizing clinical data.     

The Gut Microbiota: A Potential Gateway to Improved Health Outcomes in Breast Cancer Treatment and Survivorship

Breast cancer is the most frequently diagnosed cancer in women worldwide. The disease and its treatments exert profound effects on an individual’s physical and mental health. There are many factors that impact an individual’s risk of developing breast cancer, their response to treatments, and their risk of recurrence. The community of microorganisms inhabiting the gastrointestinal tract, the gut microbiota, affects human health through metabolic, neural, and endocrine signaling, and immune activity. It is through these mechanisms that the gut microbiota appears to influence breast cancer risk, response to treatment, and recurrence. A disrupted gut microbiota or state of ‘dysbiosis’ can contribute to a biological environment associated with higher risk for cancer development as well as contribute to negative treatment side-effects. Many cancer treatments have been shown to shift the gut microbiota toward dysbiosis; however, the microbiota can also be positively manipulated through diet, prebiotic and probiotic supplementation, and exercise. The objective of this review is to provide an overview of the current understanding of the relationship between the gut microbiota and breast cancer and to highlight potential strategies for modulation of the gut microbiota that could lead to improved clinical outcomes and overall health in this population.     

Dietary exposure to acrylamide in a group of Japanese adults based on 24-hour duplicate diet samples

Acrylamide is a probable human carcinogen and known human neurotoxin that can be generated in food through heating. Using a mathematical modelling approach, our previous study estimated long-term average dietary exposure to acrylamide in the Japanese people; however, the validity of these estimates remained unknown. Here, we aimed to obtain a more accurate estimate of acrylamide exposure that would reflect the usual practice of heat processing and consumption of foods in the population. We collected duplicate diet samples and dietary records during 24 h from a group of Japanese adults. A total of 110 duplicate diet samples were analysed for acrylamide by LC-MS/MS. Data from individual dietary records were used to examine the association between dietary acrylamide exposure and consumption of selected food groups (e.g., coffee, tea, confectioneries, and vegetables prepared at high temperature [deep-frying, stir-frying, sautéing, and baking]). Of the 110 homogenised diet samples, 108 contained detectable levels of acrylamide. Dietary exposure to acrylamide ranged from 8 to 1582 ng/kg body weight (bw)/day, with the mean value of 215 ng/kg-bw/day and median value of 143 ng/kg-bw/day. This mean value was higher than the value we previously estimated for Japanese adults using a mathematical approach. Multiple linear regression analysis showed log dietary acrylamide exposure was significantly associated with consumption of coffee and vegetables prepared at high temperature during 24-hr of sampling (adj. R² = 0.250, p < 0.001). We revealed significant difference in dietary acrylamide exposure between participants who had coffee and vegetables prepared at high temperature (median, 169 ng/kg-bw/day; range, 35–1224 ng/kg-bw/day, n = 42) and those who had none of them (median, 75 ng/kg-bw/day; range, 8–311 ng/kg-bw/day, n = 15) (Steel-Dwass test, p < 0.05).     

A Simple and Effective Mass Spectrometric Approach to Identify the Adulteration of the Mediterranean Diet Component Extra-Virgin Olive Oil with Corn Oil

Extra virgin olive oil (EVOO) with its nutraceutical characteristics substantially contributes as a major nutrient to the health benefit of the Mediterranean diet. Unfortunately, the adulteration of EVOO with less expensive oils (e.g., peanut and corn oils), has become one of the biggest source of agricultural fraud in the European Union, with important health implications for consumers, mainly due to the introduction of seed oil-derived allergens causing, especially in children, severe food allergy phenomena. In this regard, revealing adulterations of EVOO is of fundamental importance for health care and prevention reasons, especially in children. To this aim, effective analytical methods to assess EVOO purity are necessary. Here, we propose a simple, rapid, robust and very sensitive method for non-specialized mass spectrometric laboratory, based on the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) coupled to unsupervised hierarchical clustering (UHC), principal component (PCA) and Pearson’s correlation analyses, to reveal corn oil (CO) adulterations in EVOO at very low levels (down to 0.5%).     

Early impact of a fat-enriched diet on behavioral responses of male and female rats.

Prolonged high-fat diets have been shown to affect an organism's stress responsiveness at the neuroendocrine level. In the present study, the authors used a 7-day protocol of fat administration in adult rats of both sexes to investigate the early behavioral impact of a moderately fat (20%) diet, often used by Western societies, on rats' reaction to acute stress and novelty. Their results show that this diet can reduce the rats' active behavioral responses to subsequent stressors and influence their corticosterone secretion. Fat-fed male rats adopted a less active behavior to cope with forced swimming stress, whereas their exploratory behavior in the open field environment was rather increased compared with chow-fed males. Fat-fed female rats exhibited a less active behavioral response to both stress paradigms compared with their chow-fed counterparts. Fat diet abolished facilitation in corticosterone secretion following a subsequent stressor in both sexes. However, only in males did fat diet exaggerate corticosterone response to novelty, irrespective of the previous stress history of the rat. These data indicate that a short-term metabolic stress can modify the rats' stress coping strategy in interaction with the gender. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-Fat Diet Leads to Reduced Protein O-GlcNAcylation and Mitochondrial Defects Promoting the Development of Alzheimer’s Disease Signatures

The disturbance of protein O-GlcNAcylation is emerging as a possible link between altered brain metabolism and the progression of neurodegeneration. As observed in brains with Alzheimer’s disease (AD), flaws of the cerebral glucose uptake translate into reduced protein O-GlcNAcylation, which promote the formation of pathological hallmarks. A high-fat diet (HFD) is known to foster metabolic dysregulation and insulin resistance in the brain and such effects have been associated with the reduction of cognitive performances. Remarkably, a significant role in HFD-related cognitive decline might be played by aberrant protein O-GlcNAcylation by triggering the development of AD signature and mitochondrial impairment. Our data support the impairment of total protein O-GlcNAcylation profile both in the brain of mice subjected to a 6-week high-fat-diet (HFD) and in our in vitro transposition on SH-SY5Y cells. The reduction of protein O-GlcNAcylation was associated with the development of insulin resistance, induced by overfeeding (i.e., defective insulin signaling and reduced mitochondrial activity), which promoted the dysregulation of the hexosamine biosynthetic pathway (HBP) flux, through the AMPK-driven reduction of GFAT1 activation. Further, we observed that a HFD induced the selective impairment of O-GlcNAcylated-tau and of O-GlcNAcylated-Complex I subunit NDUFB8, thus resulting in tau toxicity and reduced respiratory chain functionality respectively, highlighting the involvement of this posttranslational modification in the neurodegenerative process.     

Electroantennographic and coupled gas chromatographic-electroantennographic responses of the mediterranean fruit fly,Ceratitis capitata,to male-produced volatiles and mango odor

We have identified five compounds from the headspace of calling male Mediterranean fruit flies (medfly),Ceratitis capitata (Wiedemann), and three compounds from the headspace of ripe mango (Mangifera indica L). using coupled gas chromatographic-electroantennographic (GC-EAG) recordings, coupled gas chromatographic-mass spectrometric (GC-MS) analysis, and electroantennographic (EAG) assays of standards. The male-produced volatiles eliciting responses from female antennae were ethyl-(E)-3-octenoate, geranyl acetate, (E,E)--farnesene, linalool, and indole. An EAG dose-response test of linalool enantiomers and indole with female medfly antennae showed relatively strong EAG activities, but no significant difference between (R)-(-)-linalool and (S)-(+)-linalool. The three mango volatiles were identified as (1S)-(-)--pinene, ethyl octanoate, and-caryophyllene. In addition, a strong antennal response was recorded from a contaminant,-copaene, present in a commercial sample of-caryophyllene. The EAG response amplitudes from both male and female antennae to the above three mango volatiles were significantly greater than to a hexanol control. For both male and female medfly antennae, the greatest EAG responses were elicited by-caryophyllene followed by ethyl octanoate. The mean EAG responses of female antennae to-caryophyllene and (1S)-(-)--pinene were significantly greater than those of male antennae.     

Taste thresholds and suprathreshold responses to tannin-rich plant extracts and quinine in a primate species (Microcebus murinus)

Theories of plant chemical defenses discriminate between quantitative digestibility reducers (e.g., tannins) and qualitative toxins (e.g., alkaloids). Since the differential effect on taste of these compounds is poorly known, we recorded ingestive responses of a primate species, Microcebus murinus, to four tannin-rich plant extracts and to quinine, by using the behavioral method of the two-bottle test. The efficiency of tannic extracts at precipitating protein was measured with the blue BSA method. Inhibition taste thresholds for tannins added to a moderately sweet solution varied between 0.25 and 2 g/l. The threshold for quinine hydrochloride was 0.32 g/l. The profiles of the response/concentration curves established for these astringent and bitter substances were similar, with maximal inhibition of consumption occurring for near-threshold concentrations. The large amounts of quinine required to deter this small-bodied species from feeding were unexpected, given its unspecialized frugivorous/insectivorous diet. We propose that the taste responses of Microcebus to tannins have been shaped in relation to the widespread occurrence of efficient polyphenols in food plants, while low responsiveness to quinine reflects a low risk of ingesting toxic alkaloids when feeding on ripe fruits and insects.     

Antioxidant activity in leaves of some mediterranean plants

Hexane and methanol leaf extracts of sixteen Mediterranean plant species were obtained by percolation. Higher yields were observed for methanol (16.4–47.8%) than for hexane extracts (1.3–13%). Antioxidant activity of these extracts was determined by a rapid spectrophotometric method involving the combined oxidation of beta-carotene and linoleic acid. Leaf extracts were thus characterized by an Antioxidant Activity Coefficient (AAC) ranging from 0 to 1000. Hexane extracts gave much higher AAC values than the corresponding methanol extracts. In both cases, myrtle (Myrtus communis) showed the best antioxidant effectiveness.     

Processing of an East Mediterranean phosphate ore sample by an integrated attrition scrubbing/classification scheme (part one)

ABSTRACT

In this study, an Egyptian siliceous/calcareous sedimentary phosphorite was subjected to beneficiation by unsophisticated economic means. The mineralogical and chemical examination showed that the ore sample is a typical example for the East Mediterranean phosphorites with 21.80% P₂O₅, 10.93% acid insoluble and 16.61% loss on ignition. The primary crushed sample was classified into three size fractions without any milling and they were separately subjected to an integrated attrition scrubbing study. Screening and classification on the 2.30 mm and 0.071 mm sieves were sequentially introduced with the attrition process. The effect of solid%, attrition speed and time were studied and optimized for each size fraction. Results showed that three products were produced and could be categorized according to their P₂O₅ content into the coarse tailing (+2.30 mm), the attrition concentrate (?2.30 + 0.071 mm) and the phosphate fines (?0.071 mm). The P₂O₅ contents of these products reached 12.24%, 28.72% and 18.77%, with P₂O₅ distribution reached 6.74%, 51.75% and 41.51%, respectively. A global P₂O₅ of 28.72% was obtained with a recovery of about 52%. A tentative flow-sheet for the whole process was postulated.