Chemical composition and in vitro fermentation of tannin-rich tree fruits

Dry and mature tree fruits are a potential source of protein for goats in the semi-arid areas of southern Africa, but their chemical composition and feeding value is largely unknown. This study presents the chemical composition and in vitro fermentation of indehiscent whole fruits and separated seed and hull fractions from Acacia nilotica, Acacia erubescens, Acacia sieberiana, Acacia erioloba, Piliostigma thonningii and Dichrostachys cinerea trees. Results indicate that the N contents of whole fruits ranged between 13.5 g/kg DM (A. nilotica) and 27.1 g/kg DM (A. erubescens). Seeds had a higher N content than hulls for all tree species. A. nilotica, D. cinerea and P thonningii fruits had high levels of extractable phenolics (758, 458 and 299 g/kg DM, respectively). Soluble phenolics (SPh) and ytterbium precipitable phenolics (YbPh) levels were negatively correlated to in vitro gas production but positively correlated to in vitro organic matter degradability (iOMD). Partition factors for whole fruits at 48 h ranged between 3.6 mg/ml for A. erioloba and 7.8 mg/ml for A. nilotica. Seeds of A. erioloba, A. erubescens and P thonningii were consistently fermented more efficiently throughout the incubation period compared to their whole fruits or hulls. Estimating in vitro degradability of phenolic-rich substrates through filtration procedures can give erroneous results due to the loss of soluble phenolics, which are not necessarily degradable. The feeding value of fruits from D. cinerea and A. nilotica tree species may be reduced due to the presence of high levels of phenolics. (C) 2007 Elsevier B.V. All rights reserved.

Contrasting success in the restoration of plant and phytophagous beetle assemblages of species-rich mesotrophic grasslands

Over the last 60 years changes to the management of species-rich mesotrophic grasslands have resulted in the large-scale loss and degradation of this habitat across Europe. Restoration of such grasslands on agriculturally improved pastures provides a potentially valuable approach to the conservation of these threatened areas. Over a four-year period a replicated block design was used to test the effects of seed addition (green hay spreading and brush harvest collection) and soil disturbance on the restoration of phytophagous beetle and plant communities. Patterns of increasing restoration success, particularly where hay spreading and soil disturbance were used in combination, were identified for the phytophagous beetles. In the case of the plants, however, initial differences in restoration success in response to these same treatments were not followed by subsequent temporal changes in plant community similarity to target mesotrophic grassland. It is possible that the long-term consequences of the management treatments would not be the establishment of beetle and plant communities characteristic of the targets for restoration. Restoration management to enhance plant establishment using hay spreading and soil disturbance techniques would, however, still increase community similarity in both taxa to that of species-rich mesotrophic grasslands, and so raise their conservation value.

A novel method for production of lipid hydroperoxide- or oxysterol-rich low-density lipoprotein

LDL oxidation may be important in atherosclerosis. Extensive oxidation of LDL by copper induces increased uptake by macrophages, but results in decomposition of hydroperoxides, making it more difficult to investigate the effects of hydroperoxides in oxidised LDL on cell function. We describe here a simple method of oxidising LDL by dialysis against copper ions at 4 degrees C, which inhibits the decomposition of hydroperoxides, and allows the production of LDL rich in hydroperoxides (626 +/- 98 nmol/mg LDL protein) but low in oxysterols (3 +/- 1 nmol 7-ketocholesterol/mg LDL protein), whilst allowing sufficient modification (2.6 +/- 0.5 relative electrophoretic mobility) for rapid uptake by macrophages (5.49 +/- 0.75 mu g I-125-labelled hydroperoxide-rich LDL vs. 0.46 +/- 0.04 mu g protein/mg cell protein in 18 h for native LDL). By dialysing under the same conditions, but at 37 degrees C, the hydroperoxides are decomposed extensively and the LDL becomes rich in oxysterols. This novel method of oxidising LDL with high yield to either a hydroperoxide- or oxysterol-rich form by simply altering the temperature of dialysis may provide a useful tool for determining the effects of these different oxidation products on cell function. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

Differential uptake of subfractions of triglyceride-rich lipoproteins by THP-1 macrophages

It is well known that raised plasma triglycerides (TG) are positively linked to the development of coronary heart disease. However, triglycerides circulate in a range of distinct lipoprotein subtractions and the relative atherogenicity of these subtractions is not clear. In this study, three fractions of triglyceride rich lipoprotein (TRL) were isolated from normolipidaemic males according to their differing Svedberg flotation (S-f) rates: chylomicron (CM, S-f > 400), very low-density lipoprotein (VLDL)-1 (S-f 60-400) and VLDL-2 (S-f 20-60). These fractions were incubated with THP-1 monocyte-derived macrophages for determination of cholesterol and TG accumulation, in the presence and absence of the lipoprotein lipase (LPL) inhibitor orlistat. Expression of LDL receptor related protein (LRP) and apolipoprotein B48 receptor (apoB48R) was also examined in both differentiating monocytes, and monocyte-derived macrophages, incubated with TRL. VLDL-I caused a significantly greater accumulation of TG within macrophages compared to VLDL-2. Binding studies also tended to show a greater preference for VLDL-1. No change in expression of LRP or apoB48R was observed in fully differentiated macrophages incubated with VLDL-1, VLDL-2 or CM, although a greater expression of LRP mRNA was observed in differentiating monocytes exposed to VLDL-1, compared to those incubated with CM or VLDL-2. TG loading in response to all three TRL fractions was blocked by orlistat, suggesting that it is likely that the major pathway for uptake of TG was hydrolysis by LPL. Calculations suggested that direct uptake of particles accounts for between 12 and 25% of total TAG uptake. In conclusion, THP monocyte-derived macrophages demonstrate a preference for VLDL-1, both through the LPL pathway and by direct uptake of whole particles. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Triglyceride-rich lipoproteins inhibit cholesterol efflux to apolipoprotein (apo) A1 from human macrophage foam cells

High circulating levels of triglyceride-rich lipoproteins (TGRL) represent an independent risk factor for coronary artery disease. Here, we show that TGRL inhibit the efflux of cholesterol from 'foam cell' macrophages to lipid-poor apolipoprotein (apo) A1, and may thereby inhibit arterial reverse cholesterol transport and promote the formation of atherosclerotic lesions. Human (THP-1) monocyte-derived macrophages were pre-incubated (48h) with acetylated low-density lipoprotein (AcLDL) to provide a foam cell model of cholesterol efflux to apoA1. Pre-incubation of macrophage 'foam cells' with TGRL (0-200 mug/ml, 0-24 h) inhibited the efflux of exogenously radiolabelled ([H-3]), endogenously synthesised ([C-14]) and cellular cholesterol mass to lipid-poor apoA1, but not control medium, during a (subsequent) efflux period. This inhibition is dependent upon the length of prior exposure to, and concentration of, TGRL employed, but is independent of changes in intracellular triglyceride accumulation or turnover of the cholesteryl ester pool. Despite the negative impact of TGRL on cholesterol efflux, major proteins involved in this process-namely apoE, ABCA1, SR-B1 and caveolin-1-were unaffected by TGRL pre-incubation, suggesting that exposure to these lipoproteins inhibits an alternate, and possibly novel, anti-atherogenic pathway. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Effects of oils rich in eicosapentaenoic and docosahexaenoic acids on the oxidizability and thrombogenicity of low-density lipoprotein

Consumption of oily fish and fish oils is associated with protection against cardiovascular disease. Paradoxically, long-chain polyunsaturated fatty acids present in low-density lipoprotein (LDL) are suggested to be susceptible to oxidation. It is not clear whether eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have similar effects on the susceptibility of LDL to oxidation or whether they affect the thrombogenicity of oxidized LDL. This study examined the influence of highly purified preparations of EPA and DHA on LDL oxidizability and LDL-supported thrombin generation in healthy human volunteers. Forty-two healthy volunteers were randomly assigned to receive olive oil (placebo), an EPA-rich oil or a DHA-rich oil for 4 weeks at a dose of 9 g oil/day. EPA and DHA were incorporated into LDL phospholipids and cholesteryl esters during the supplementation period, but were progressively lost during ex vivo copper-mediated oxidation. Following supplementation, the EPA treatment significantly increased the formation of conjugated dienes during LDL oxidation compared with baseline, whereas the DHA treatment had no effect. Neither treatment significantly affected the lag time for oxidation, oxidation rate during the propagation phase or maximum diene production. Neither EPA nor DHA significantly affected the thrombotic tendency of oxidized LDL compared with the placebo, although DHA tended to decrease it. In conclusion, there are subtle differences in the effects of EPA and DHA on the oxidizability and thrombogenicity of LDL. DHA does not appear to increase the susceptibility of LDL to oxidation to the same degree as EPA and has a tendency to decrease LDL-supported thrombin generation. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

In vitro evaluation of the prebiotic activity of a pectic oligosaccharide-rich extract enzymatically derived from bergamot peel

The prebiotic effect of a pectic oligosaccharide-rich extract enzymatically derived from bergamot peel was studied using pure and mixed cultures of human faecal bacteria. This was compared to the prebiotic effect of fructo-oligosaccharides (FOS). Individual species of bifidobacteria and lactobacilli responded positively to the addition of the bergamot extract, which contained oligosaccharides in the range of three to seven. Fermentation studies were also carried out in controlled pH batch mixed human faecal cultures and changes in gut bacterial groups were monitored over 24 h by fluorescent in situ hybridisation, a culture-independent microbial assessment. Addition of the bergamot oligosaccharides (BOS) resulted in a high increase in the number of bifidobacteria and lactobacilli, whereas the clostridial population decreased. A prebiotic index (PI) was calculated for both FOS and BOS after 10 and 24 h incubation. Generally, higher PI scores were obtained after 10 h incubation, with BOS showing a greater value (6.90) than FOS (6.12).

Effects of oils rich in eicosapentaenoic and docosahexaenoic acids on immune cell composition and function in healthy humans

Background: Supplementation of the diet with fish oil, which is rich in the long-chain n-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is reported to decrease several markers of immune function. However, whether EPA, DHA, or a combination of the 2 exerts these immunomodulatory effects is unclear. Objective: The objective of the study was to determine the effects of supplementation with an EPA-rich or DHA-rich oil on a range of immune outcomes representing key functions of human neutrophils, monocytes, and lymphocytes in healthy humans. Design: In a placebo-controlled, double-blind, parallel study, 42 healthy subjects were randomly allocated to receive supplementation with either placebo (olive oil), EPA (4.7 g/d), or DHA (4.9 g/d) for 4 wk. Blood samples were taken before and after supplementation. Results: The fatty acid composition of plasma phospholipids and neutrophils was dramatically altered by supplementation with EPA or DHA, and the effects of EPA differed notably from those of DHA. DHA supplementation decreased T lymphocyte activation, as assessed by expression of CD69, whereas EPA supplementation had no significant effect. Neither the EPA-rich oil nor the DHA-rich oil had any significant effect on monocyte or neutrophil phagocytosis or on cytokine production or adhesion molecule expression by peripheral blood mononuclear cells. Conclusions: Supplementation with DHA, but not with EPA, suppresses T lymphocyte activation, as assessed by expression of CD69. EPA alone does not, therefore, influence CD69 expression. No other marker of immune function assessed in this study was significantly affected by either EPA or - DHA.

Greater enrichment of triacylglycerol-rich lipoproteins with apolipoproteins E and C-III after meals rich in saturated fatty acids than after meals rich in unsaturated fatty acids

Background: Although there is considerable interest in the postprandial events involved in the absorption of dietary fats and the subsequent metabolism of diet-derived triacylglycerol-rich lipoproteins, little is known about the effects of meal fatty acids on the composition of these particles. Objective: We examined the effect of meal fatty acids on the lipid and apolipoprotein contents of triacylglycerol-rich lipoproteins. Design: Ten normolipidemic men received in random order a mixed meal containing 50 L, of a mixture of palm oil and cocoa butter [rich in saturated fatty acids (SFAs)], safflower oil [n-6 polyunsaturated fatty acids (PUFAs)]. or olive oil [monounsaturated fatty acids (MUFAs)] on 3 occasions. Fasting and postprandial apolipoproteins B-48. B-100, E. C-II, and C-III and lipids (triacylglycerol and cholesterol) were measured in plasma fractions with Svedberg flotation rates (S-f) >400 S-f 60-400, and S-f 20 - 60. Results: Calculation of the composition of the triacylglycerol-rich lipoproteins (expressed per mole of apolipoprotein B) showed notable differences in the lipid and apolipoprotein contents of the SFA-enriched particles in the S-f > 400 and S-f 60-400 fractions. After the SFA meal, triacylglycerol-rich lipoproteins in these fractions showed significantly greater amounts of triacylglycerol and of apolipoproteins C-II (Sf 60-400 fraction only), C-III, and E than were found after the MUFA meal (P < 0.02) and more cholesterol, apolipoprotein C-III (Sf > 400 fraction only), and apolipoprotein E than after the PUFA meal (P < 0.02). Conclusions: Differences in the composition of S-f > 400 and S-f 60-400 triacylglycerol-rich lipoproteins formed after saturated compared with unsaturated fatty acid-rich meals may explain differences in the metabolic handling of dietary fats.

Impact of saturated, polyunsaturated and monounsaturated fatty acid-rich micelles on lipoprotein synthesis and secretion in Caco-2 cells

Meal fatty acids have been shown to modulate the size and composition of triacylglycerol (TAG)-rich lipoproteins influencing the magnitude and duration of the postprandial plasma TAG response. As a result there is considerable interest in the origin of these meal fatty-acid induced differences in particle composition. Caco-2 cells were incubated over 4 days with fatty acid mixtures resembling the composition of saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acid (PUFA)-rich meals fed in a previous postprandial study to determine their impact on lipoprotein synthesis and secretion. The MUFA- and PUFA-rich mixtures supported greater intracellular TAG, but not cholesterol accumulation compared with the SFA-rich mixture (P < 0.001). The MUFA-rich mixture promoted significantly greater TAG and cholesterol secretion than the other mixtures and significantly more apolipoprotein B-100 secretion than the PUFA-rich mixture (P < 0.05). Electron microscopy revealed the SFA-rich mixture had led to unfavourable effects on cellular morphology, compared with the unsaturated fatty acid-rich mixtures. Our findings suggest the MUFA-rich mixture, may support the formation of a greater number of TAG-rich lipoproteins, which is consistent with indirect observations from our human study. Our electron micrographs are suggestive that some endocytotic uptake of MUFA-rich taurocholate micelles may promote greater lipoprotein synthesis and secretion in Caco-2 cells.

Volatile oxidation compounds in a conjugated linoleic acid-rich oil

In this Study, volatile oxidation compounds formed in a commercial conjugated linoleic acid (CLA)-rich oil were quantified and results compared to those found in safflower oil (rich in linoleic acid, LA). Intact oil samples and pure triacylglycerols obtained following elimination of tocopherols and minor compounds were oxidised at 60 degrees C, and volatile oxidation compounds were analysed by solid phase microextraction-gas chromatography with flame ionisation detector and mass spectrometer. Results showed that while, as expected, hexanal was the major volatile oxidation compound found in oil and triacylglycerols rich in LA, both hexanal and heptanal equally were the most abundant compounds in oil and triacylglycerols rich in CLA. Besides, samples rich in CLA also showed significantly high quantities of trans-2-octenal and trans-2-nonenal and the latter, along with heptanal, were absent in samples rich in LA. Results for CLA samples were not easy to interpret since major volatiles found are not expected from theoretically stable hydroperoxides formed in CLA and could in part derive from dioxetanes coming from 1,2-cycloadclitions of CIA with oxygen. Overall, results obtained support evidence that oxidation mechanisms of CLA may differ than those of LA. Also, it was concluded that heptanal determination could serve as a useful marker of oxidation progress in CLA-rich oils. (C) 2008 Elsevier Ltd. All rights reserved.

Rich and famous: recognition-based judgment in the Sunday Times rich list

Recognition as a cue to judgment in a novel, multi-option domain (the Sunday Times Rich List) is explored. As in previous studies, participants were found to make use of name recognition as a cue to the presumed wealth of individuals. Names that were recognized were judged to be the richest name from amongst the set presented at above chance levels. This effect persisted across situations in which more than one name was recognized; recognition was used as an inclusion criterion for the sub-set of names to be considered the richest of the set presented. However, when the question was reversed, and a “poorest” judgment was required, use of recognition as an exclusion criterion was observed only when a single name was recognized. Reaction times when making these judgments also show a distinction between “richest” and “poorest” questions with recognition of none of the options taking the longest time to judge in the “richest” question condition and full recognition of all the names presented taking longest to judge in the “poorest” question condition. Implications for decision-making using simple heuristics are discussed.

Long chain n-3 PUFA-rich meal reduced postprandial measures of arterial stiffness

Background & aims The consumption of long chain n − 3 polyunsaturated fatty acids (LC n − 3 PUFA) is known to be cardio-protective. Data on the influence of LC n − 3 PUFA on arterial stiffness in the postprandial state is limited. The aim of this study was to investigate the acute effects of a LC n − 3 PUFA-rich meal on measures of arterial stiffness. Methods Twenty-five healthy subjects (12 men, 13 women) received a control and a LC n − 3 PUFA-rich meal on two occasions in a random order. Arterial stiffness was measured at baseline, 30, 60, 90, 120, 180 and 240 min after meal consumption by pulse wave analysis and digital volume pulse to derive an augmentation index and a stiffness index respectively. Blood samples were taken for measurement of lipids, glucose and insulin. Results Consumption of the LC n − 3 PUFA-rich meal had an attenuating effect on augmentation index (P = 0.02) and stiffness index (P = 0.03) compared with the control meal. A significant treatment effect (P = 0.036) was seen for plasma non-esterified fatty acids concentrations. Conclusions These data indicate that acute LC n − 3 PUFA-rich meal consumption can improve postprandial arterial stiffness. This has important implications for the beneficial properties of LC n − 3 PUFA and cardiovascular risk reduction.

The restoration of phytophagous beetles in species-rich chalk grasslands

This study focuses on the restoration of chalk grasslands over a 6-year period and tests the efficacy of two management practices, hay spreading and soil disturbance, in promoting this process for phytophagous beetles. Restoration success for the beetles, measured as similarity to target species-rich chalk grassland, was not found to be influenced by either management practice. In contrast, restoration success for the plants did increase in response to hay spreading management. Although the presence of suitable host plants was considered to dictate the earliest point at which phytophagous beetles could successfully colonized, few beetle species colonized as soon as their host plants became established. Morphological characteristics and feeding habits of 27 phytophagous beetle species were therefore tested to identify factors that limited their colonization and persistence. The lag time between host plant establishment and colonization was greatest for flightless beetles. Beetles with foliage-feeding larvae both colonized at slower rates than seed-, stem-, or root-feeding species and persisted within the swards for shorter periods. Although the use of hay spreading may benefit plant communities during chalk grassland restoration, it did not directly benefit phytophagous beetles. Without techniques for overcoming colonization limitation for invertebrate taxa, short-term success of restoration may be limited to the plants only.