The effect of fish oil supplementation of pregnant and lactating ewes on milk production and lamb performance

Supplementation of pregnant ewes with long-chain n-3 polyunsaturated fatty acids (PUFA) demonstrably improves indicators of neonatal lamb vigour, potentially improving the number of lambs reared per ewe. The present study investigated the effect of supplementing ewes with fish oil and vitamin E (α-tocopherol acetate) throughout both pregnancy and lactation on the performance of lactating ewes and sucking lambs. Forty-eight ewes were supplemented with one of four concentrates containing either Megalac or fish oil plus a basal (50 mg/kg) or supranutritional (500 mg/kg) concentration of vitamin E from 6 weeks pre-partum until 4 weeks post partum in a two-by-two factorial randomised-block design. All concentrates were formulated to contain approximately 60 g/kg supplemental fatty acids. Ewes were housed, penned on sawdust and offered straw ad libitum. Blood samples were taken from ewes and lambs at intervals throughout the experiment and milk samples were obtained at 21 days into lactation. There was no notable effect of dietary vitamin E concentration upon ewe or lamb performance. Ewe dry-matter (DM) intake and yield were unaffected by dietary treatment, although ewes fed fish oil lost less weight during lactation (-1.88 kg compared with -3.97 kg for Megalac-supplemented ewes; P < 0.01). Milk fat concentrations (67.3 g/kg compared with 91.8 g/kg; P < 0.01) and yields (6.65 g/h v. 9.26 g/h; P < 0.01) were reduced in ewes fed fish oil and these decreases were associated with lower litter-growth rates (0.49 g/day compared with 0.54 g/day; P < 0.05). Milk protein yield was increased by fish oil supplementation (3.82 g/h) compared with Megalac supplementation (3.28 g/h; P < 0.05); moreover, there was an interaction between fat source and vitamin E concentration in that both protein concentration and yield were significantly lower in milk from ewes fed treatment with Megalac + basal vitamin E (MB) compared with the other three treatments. Fish oil supplementation increased the concentrations of C18:1 trans-, cis-9, trans-11 conjugated linoleic acid (CLA), C20:5 (n-3) and C22:6 (n-3) within ewe plasma, milk and lamb plasma. The mechanisms by which fish oil supplementation affects milk composition warrants further investigation.     

The effect of dietary supplementation of fish oil on experimental myocardial infarction

The effect of altering the abundance of precursors and inhibitors of prostaglandin formation by dietary supplements of fish oil was investigated in dogs with experimentally induced myocardial infarction. Prior to induction, 10 male mongrel dogs were fed standard dog chow supplemented with 25% of the total calories as menhaden oil for 36 to 45 days. The fatty acid composition of the lipids in plasma and platelets changed to reflect the increased intake of polyunsaturated fatty acids of the n-3 type. Thrombosis and subsequent infarction was induced by electrical stimulation of the left circumflex coronary artery of ambulatory dogs that were monitored by telemetry. Upon stimulation of control animals, the frequency of ectopic beats rose from less than 10% at the beginning to about 80% after 19 hours. In contrast, the oil-fed dogs maintained a more normal ECG pattern, showing less than 30% ectopic beats after 19 hours. In these animals, the size of infarction (measured by formazan formation) was 3% of the left ventricle compared to 25% in the control animals. The results suggest that dietary supplementation with fish oil may be beneficial in reducing myocardial damage associated with coronary artery thrombosis.     

Maternal fish oil supplementation in lactation: effect on developmental outcome in breast-fed infants

Docosahexaenoic acid (DHA) accumulates in the brain during the 1st and 2nd years of life. The objective of this study was to see if an increased content of DHA in breast-milk via maternal fish oil (FO)-supplementation affects mental development in term infants. one hundred twenty-two Danish mothers with a habitual fish intake below the population median were randomized to 4.5 g.d(-1) of FO or olive oil (OO) for the first four months of lactation. Fifty-three mothers with habitual fish intake in the highest quartile were included as reference group. The effect of the resulting increase in infant DHA-intake and RBC-DHA level was assessed on problem solving ability at nine months and language at one and two years of age. Infants in the three groups performed equally well on the problem test and no association was observed between problem solving and erythrocyte-DHA at four months. Passive vocabulary at one year was lower in the children of the FO- compared with the OO-group (P < 0.05), but no differences were found at two years of age. Word comprehension at one year was inversely associated with erythrocyte-DHA at four months. The trial indicate a small effect of DHA levels in breast-milk on early language development of breast-fed infants.     

Effects of fish oil on lymphocyte proliferation,cytokine production and intracellular signalling in weanling pigs

It has been widely documented that fish oil attenuates inflammatory responses partially via down-regulation of T-lymphocyte function. To determine the anti-inflammatory role of fish oil in weanling pigs, we investigated the effects of fish oil and its functional constituents on peripheral blood lymphocyte proliferation, cytokine production and subsequent intracellular signalling in inflammatory-challenged weanling pigs and in in vitro cultured lymphocytes. Fish oil (7%) or corn oil (7%) was supplemented to 72 crossbred pigs (7.6 ± 0.3 kg BW and 28 ± 3 days of age) in a 2 × 2 factorial experiment that included an Escherichia coli lipopolysaccharide (LPS) challenge (challenged or not challenged). On day 14 and 28 of the experiment, 200 μg/kg BW of LPS or an equivalent amount of sterile saline was administered to the pigs by intraperitoneal injection. Blood samples were collected on days 15 and 29 to determine peripheral blood lymphocyte proliferation, interleukin-1β (IL-1β) and interleukin-2 (IL-2) production. The results showed that inflammatory challenge decreased average daily gain (P < 0.05) and average daily feed intake (P < 0.05) during days 15 - 28. Fish oil supplementation had no effect on growth performance. Inflammatory challenge increased lymphocyte proliferative response to concanavalin A (Con A) (P < 0.05) following each challenge. Fish oil tended to suppress (P < 0.1) the proliferation following the first challenge. Similarly, fish oil tended to reduce IL-1β production (P < 0.1) following the second challenge and IL-2 (P < 0.1) production following the first challenge in both challenged and unchallenged pigs compared with corn oil. In parallel in vitro experiments, peripheral blood lymphocytes of weanling pigs were incubated with various concentrations of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or linoleic acid (LA) (0, 20, 40, 60, 80, 100 μg/ml). EPA, DHA and high levels of LA predominantly suppressed IL-1β (P < 0.05), IL-2 (P < 0.05) production and subsequent lymphocyte proliferation (P < 0.05). Low levels of LA increased (P < 0.05) IL-2 production. Compared with LA, EPA resulted in a stronger inhibition of lymphocyte proliferation (P < 0.05) and IL-2 (P < 0.01), and DHA resulted in a stronger inhibition of IL-1β (P < 0.05) and IL-2 (P < 0.01). To elucidate the mechanism(s) by which fish oil and its functional constituents suppressed lymphocyte function, the kinetics of intracellular [Ca^{2 +}]_i and protein kinase C activity were determined in in vitro experiments. EPA, DHA and LA exerted very similar dose-dependent stimulatory effects on intracellular Ca^{2 +}. EPA and DHA inhibited protein kinase C activity (P < 0.05), while LA had no significant effect (P > 0.05). These results suggest that fish oil and its functional constituents (EPA and DHA) exerted an anti-inflammatory effect by down-regulation of lymphocyte activation in weanling pigs, possibly by manipulation of intracellular signalling.     

ALOX5 gene variants affect eicosanoid production and response to fish oil supplementation

The objective of this study was to determine whether 5-lipoxygenase (ALOX5) gene variants associated with cardiovascular disease affect eicosanoid production by monocytes. The study was a randomized, double-masked, parallel intervention trial with fish oil (5.0 g of fish oil daily, containing 2.0 g of eicosapentaenoic acid [EPA] and 1.0 g of docosahexaenoic acid [DHA]) or placebo oil (5.0 g of corn/soy mixture). A total of 116 subjects (68% female, 20-59 years old) of African American ancestry enrolled, and 98 subjects completed the study. Neither ALOX5 protein nor arachidonic acid-derived LTB4, LTD4, and LTE4 varied by genotype, but 5-hydroxyeicosatetraenoate (5-HETE), 6-trans-LTB4, 5-oxo-ETE, 15-HETE, and 5,15-diHETE levels were higher in subjects homozygous for the ALOX5 promoter allele containing five Sp1 element tandem repeats ("55" genotype) than in subjects with one deletion (d) (three or four repeats) and one common ("d5" genotype) allele or with two deletion ("dd") alleles. The EPA-derived metabolites 5-HEPE and 15-HEPE and the DHA-derived metabolite 17-HDoHE had similar associations with genotype and increased with supplementation; 5-HEPE and 15-HEPE increased, and 5-oxo-ETE decreased to a greater degree in the 55 than in the other genotypes. This differential eicosanoid response is consistent with the previously observed interaction of these variants with dietary intake of omega-3 fatty acids in predicting cardiovascular disease risk.     

The protective effect of dietary fish oil on murine lupus

Dietary marine lipids markedly reduce the severity of glomerulonephritis and its associated mortality in inbred strains of mice developing autoimmune disease, a model for human systemic lupus erythematosus. We report here the influence of varying the dose of menhaden oil and the timing of its administration on the mortality of female (NZB x NZW) F1 mice. After ingesting 25 wt% menhaden oil (MO) for periods of 1.5 weeks to 12 months, there was a stable content of tissue n-3 fatty acids, with total n-3 fatty acids of 28% and 35% in spleen and liver, respectively. The extent of protection from mortality was dependent on the dose of MO with marked protection at doses of 11 to 25%, marginal protection at 5.5% and no protection at 2.5% MO. Delay in the institution of MO until ages 5 or 7 months still resulted in large reductions of mortality. Conversely, institution of a MO diet from 6 weeks until ages 5 to 7 months followed by a change to beef tallow resulted in little protection. Serum levels of 4 cyclooxygenase products were reduced ranging from 26 to 76% in mice fed MO diets, compared to mice fed beef tallow, based on radioimmunoassay. The degree of reduction of mortality on different doses of MO was correlated best with tissue levels of C22:5, and levels of C20:5 and C22:6 were similar at high and low doses of MO, suggesting that levels of 22:5 may be related to the protective effects of marine lipids on autoimmune disease.     

The protective effect of dietary fish oil on murine lupus

Dietary marine lipids markedly reduce the severity of glomerulonephritis and its associated mortality in inbred strains of mice developing autoimmune disease, a model for human systemic lupus erythematosus. We report here the influence of varying the dose of menhaden oil and the timing of its administration on the mortality of female (NZB x NZW) F₁ mice. After ingesting 25 wt% menhaden oil (MO) for periods of 1.5 weeks to 12 months, there was a stable content of tissue n-3 fatty acids, with total n-3 fatty acids of 28% and 35% in spleen and liver, respectively. The extent of protection from mortality was dependent on the dose of MO with marked protection at doses of 11 to 25%, marginal protection at 5.5% and no protection at 2.5% MO. Delay in the institution of MO until ages 5 or 7 months still resulted in large reductions of mortality. Conversely, institution of a MO diet from 6 weeks until ages 5 to 7 months followed by a change to beef tallow resulted in little protection. Serum levels of 4 cyclooxygenase products were reduced ranging from 26 to 76% in mice fed MO diets, compared to mice fed beef tallow, based on radioimmunoassay. The degree of reduction of mortality on different doses of MO was correlated best with tissue levels of C22:5, and levels of C20:5 and C22:6 were similar at high and low doses of MO, suggesting that levels of 22:5 may be related to the protective effects of marine lipids on autoimmune disease.     

Effect of fish oil supplementation on plasma oxidant/antioxidant status in rats

The aim of this study was to investigate effect of dietary omega-3 fatty acid supplementation on the indices of in vivo lipid peroxidation and oxidant/antioxidant status of plasma in rats. The plasma thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) levels, and activities of xanthine oxidase (XO), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) were studied in male Wistar Albino rats after ingestion of 0.4 g/kg fish oil (rich in omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid) for 30 days and compared to untreated control rats. The rats in the treated group had significantly higher SOD activity (P < 0.001), NO levels (P < 0.01) and decreased TBARS levels (P < 0.05) with respect to controls whereas GSH-Px and XO activities were not significantly different between the groups. None of the measured parameters had significant correlation with each other in both groups. We conclude that dietary supplementation of omega-3 fatty acids may enhance resistance to free radical attack and reduce lipid peroxidation. These results support the notion that omega-3 fatty acids may be effective dietary supplements in the management of various diseases in which oxidant/antioxidant defence mechanisms are decelerated.     

The preventive effect of fish oil on abdominal aortic aneurysm development

Abdominal aortic aneurysm (AAA) is a vascular disease involving gradual dilation of the abdominal aorta and high rupture‐related mortality rates. AAA is histologically characterized by oxidative stress, chronic inflammation, and extracellular matrix degradation in the vascular wall. We previously demonstrated that aortic hypoperfusion could cause the vascular inflammation and AAA formation. However, the preventive method for hypoperfusion‐induced AAA remains unknown. In this study, we evaluated the effect of fish oil on AAA development using a hypoperfusion‐induced AAA animal model. Dilation of the abdominal aorta in the fish oil administration group was smaller than in the control group. Collagen destruction and oxidative stress were suppressed in the fish oil administration group than in the control group. These results suggested that fish oil could prevent the development of AAA induced by hypoperfusion.     

Differences between in vivo and in vitro production of eicosanoids following long-term dietary fish oil supplementation in the rat.

The effects of different lipid supplements on endogenous and exogenous production of eicosanoids were investigated in the rat following a 12-month pre-feeding period. The urinary excretion of tetranorprostanemonoic (TPM) and tetranorprostanedioic (TPD) acids was measured as an index of endogenous production whilst myocardial release of PGI2 and TXA2 was estimated under in vitro conditions. Compared to the reference group, n-3 PUFA rich tuna fish oil (TFO) fed rats displayed a near doubling of endogenous (TPM + TPD) synthesis; however, myocardial production was reduced by 32% (PGI2) and 55% (TXA2). Sheep fat supplementation also caused a 62% rise in urinary tetranor metabolites but in contrast to TFO feeding, myocardial production in vitro also showed a significant increase (P less than 0.05). Considerable changes in PUFA profile of plasma, heart and kidney occurred as a result of dietary lipid treatment and in addition a high tissue specificity was also noted with regard to the incorporation and conversion of dietary n-3 PUFA. For example, the heart showed a low EPA (1.2%) and high DHA (28.0%), whereas their proportions in the kidney were near equal (6-7%). As only the TFO diet exerted a significant effect on the proportion of AA, the changes in eicosanoid production cannot be fully explained on the basis of precursor/inhibitor availability. The results probably reflect the complex interactions between fatty acid substrates, release mechanisms and biosynthetic enzymes.     

Formation of PGI3 in the rat during dietary fish oil supplementation

Conflicting results exist in the literature on the conversion of eicosapentaenoic acid (EPA) to trienoic prostaglandins and its influence on the formation of dienoic prostaglandins from arachidonic acid (AA). Tissues from animals fed fish oils produce little, if any, trienoic prostaglandins and reduced amounts of dienoic ones. Excretion of the major urinary metabolite of PGI2 is not reduced in humans taking fish oil, however, and substantial amounts of one derived from PGI3 have been found, by GC/MS. We have addressed this possible species difference by examining the urine of rats fed fish oil for 2.3 dinor-6-keto-PGF1 alpha and its delta 17 analog, formed from PGI2 and PGI3, respectively, and compared them with rats fed corn oil. Fatty acid differences in erythrocyte and aortic lipids were also determined. Rats fed fish oil do make PGI3 from eicosapentaenoic acid in vivo and do not suppress their production of PGI2, despite having more EPA than AA in aortic lipids.     

Whole blood production of thromboxane, prostacyclin and leukotriene B4 after dietary fish oil supplementation in man: effect of vitamin E

12 subjects were given 30 ml/day of a fish oil already stabilized with vitamin E (1.5 IU/g) and other natural antioxidants (fish oil, FO), and the same fish oil supplemented with extra vitamin E (to total 4.5 IU/g) (FO+E), in a randomized double-blind cross-over study. The whole blood production of thromboxane B₂, measured in serum, was reduced after 4 weeks of ingestion of both FO+E (by 47%, P < 0.01) and of FO (by 40%, P < 0.05) whereas 6-keto-PGF_1α increased slightly in both cases, by 4% and 5% respectively, both NS. Leukotriene B₄ production decreased on both FO+E (by 20%, NS) and FO (by 17%, P < 0.05). This study thus showed that a stabilized fish oil had marked effects on eicosanoid production, which may be important for its cardiovascular effect. Further supplementation with vitamin E had no additional effect, indicating that the vitamin E content (1.5 IU/g) in this stabilized fish oil might have been optimal.     

Supressive effect of maslinic acid from pomace olive oil on oxidative stress and cytokine production in stimulated murine macrophages

The pentacyclic triterpene maslinic acid (MA) is a natural compound present in the non glyceride fraction of pomace olive oil, also called orujo olive oil. This compound has previously demonstrated antioxidant properties against lipid peroxidation in vitro, but its effects on reactive oxygen and nitrogen-derived species and pro-inflammatory cytokines generated by a cell system have not yet been investigated. In this study, we have tested the effect of MA upon oxidative stress and cytokine production using peritoneal murine macrophages. MA significantly inhibited the enhanced production of nitric oxide (NO) induced by lypopolysaccharide (LPS) when it was measured by the nitrite production with an inhibitory concentration 50% value (IC(50)) of 25.4 microM. This inhibiting effect seems to be consequence of an action at the level of the LPS-induction of the inducible nitric oxide synthethase (iNOS) gene enzyme expression rather than to a direct inhibitory action on enzyme activity. The secretion of the inflammatory cytokines interleukine-6 and TNF-a from LPS-stimulated murine macrophages was also significantly reduced (p < 0.05 and 0.01) by 50 and 100 microM of MA. In addition, reactive oxygen species were measured after stimulation with phorbol-12-myristate-13-acetate (PMA). Thus, pre-treatment with MA reduced the generation of hydrogen peroxide from stimulated macrophages in a dose-dependent manner (IC(50): 43.6 microM) as assayed by the oxidation of the peroxidase enzyme. However, no inhibitory effect on superoxide release, measured by the reduction of ferricytochrome c, was observed after the pretreatment with MA in the culture medium.These results suggest a potential biopharmaceutical use of this hydroxy-pentacyclic triterpene derivative, present in orujo olive oil, on preventing oxidative stress and pro-inflammatory cytokine generation.     

Effect of fish oil and sunflower oil supplementation on milk conjugated linoleic acid content for grazing dairy cows

The objective of this study was to determine the effect of adding fish oil (FO) and sunflower oil (SFO) to grazing dairy cows’ diets on the temporal changes in milk conjugated linoleic acid (cis-9, trans-11 CLA). Sixteen Holstein cows were divided into two diet regimen groups. One group (CONT) was fed a basal diet (7.6 kg DM basis) plus 400 g animal fat. The other group (FOSFO) were fed a basal diet plus 100 g of FO and 300 g of SFO (FOSFO). The cows were milked twice a day and milk samples were collected every 3-day for a period of 21 days. Both groups grazed together on pasture ad libitum and fed treatment diets after the morning and afternoon milking. Milk production, milk fat percentages, milk fat yield, milk protein percentages, and milk protein yield were not affected (P>0.05) by treatment diets. The concentrations of cis-9 trans-11 CLA and vaccenic acid (VA) in milk fat were higher (P<0.05) for cows fed the FOSFO over 3 week of lipid supplementation. The concentration of cis-9 trans-11 CLA in milk fat reached maximum on day 3 with both diets and remained relatively constant thereafter. The concentration of VA in milk fat followed the same pattern of temporal changes as cis-9 trans-11 CLA. In conclusion, milk cis-9, trans-11 CLA and VA concentrations increased with FO and SFO supplementation compared with the CONT diet and the increase reached a plateau on day 3 of supplementation and remained relatively constant throughout the remainder of the study.     

The influence of fish oil supplementation on plasma lipoproteins and arterial lipids in vervet monkeys with established atherosclerosis.

There is controversy about whether supplementing diets with marine fish oil can regress, promote or prevent atherosclerosis. Therefore the effects of an Atlantic pilchard oil (FO) supplement and dietary change were measured in a proven atherosclerosis model. Vervet or African Green monkeys were fed an atherogenic diet (AD) for long enough to ensure progression before treatments started. Matched groups were then treated for 20 months, either by adding FO to the AD (AD/FO), or by changing to a therapeutic diet with FO (TD/FO). Control treatments consisted of supplementing with sunflower oil (SO) instead of FO, so that treatments were AD/SO and TD/SO. The same total polyunsaturates were supplied by the FO and SO and the dose of FO was realistic (2.5% of total energy). A reference group (R) received the TD with no oil supplements. Supplementing with FO did not change the concentrations of total, low or high density lipoprotein cholesterol in plasma. After The AD/FO the intimas of aortas contained more total (p < or = 0.001), free (p < or = 0.05) and esterified (p < or = 0.05) cholesterol, total phospholipid (p < or = 0.01) and sphingomyelin (p < or = 0.05) than after the AD/SO. After FO supplementation eicosapentaenoic acid was significantly higher and arachidonic acid significantly lower in the plasma and aorta intima phosphatidylcholine. None of these changes was anti-atherogenic in terms of atherosclerosis measured in the same individuals (1). Nor did FO increase the efficacy of the TD.     

Brain and systemic glucose metabolism in the healthy elderly following fish oil supplementation

Cerebral metabolic rate of glucose (CMRg) is lower in individuals affected by cognitive decline and dementia, especially in Alzheimer's disease. However, as yet there is no consensus as to whether CMRg decreases during healthy aging. Epidemiological studies show that weekly consumption of fish abundant in ω3 fatty acids has a protective effect on cognition during aging. Thus, the primary objective of this human study was to use positron emission tomography analysis with (18)F-fluorodeoxyglucose to evaluate whether supplementation with a fish oil rich in ω3 fatty acids increases cerebral glucose metabolism in young or elderly adults. Healthy young (23±5y old; n=5) and elderly (76±3y old; n=6) women and men were included in the study. Semi-quantitative expression of the data as 'standardized uptake values' showed that elderly participants had significantly lower cerebral glucose metabolism compared with the young group. However, when expressed quantitatively a CMRg, there was no effect of age or ω3 supplementation on glucose metabolism in any of the brains regions studied. Higher plasma triglyceride levels and higher plasma insulin levels were associated with lower CMRg in several regions, suggesting that a trend towards the metabolic syndrome may be associated with cerebral hypometabolism. We conclude that under these experimental conditions, ω3 supplementation did not affect brain glucose metabolism in the healthy elderly. Future studies in this area should address whether glucose intolerance or other conditions linked to the metabolic syndrome impact negatively on brain glucose metabolism and cognition.     

Temporal changes in human skeletal muscle and blood lipid composition with fish oil supplementation

The aim of this study was to examine changes in the lipid profile of red blood cells and muscle tissue along with the expression of anabolic signalling proteins in human skeletal muscle. Following a 2-week control period, 10 healthy male participants consumed 5 g d⁻¹ of fish oil (FO) for 4 weeks. Muscle biopsies and venous blood samples were collected in the fasted state 2 weeks prior (W-2) and immediately before (W0) the initiation of FO supplementation for internal control. Muscle biopsies and venous blood samples were again obtained at week 1 (W1), 2 (W2) and 4 (W4) during FO supplementation for assessment of changes in lipid composition and expression of anabolic signalling proteins. There was no change in the composition of any lipid class between W-2 and W0 confirming control. Following FO supplementation n-3 polyunsaturated fatty acid (n-3 PUFA) muscle lipid composition was increased from W0 to W2 and continued to rise at W4. n-3 PUFA blood lipid composition was increased from W0 to W1 and remained elevated for the remaining time points. Total protein content of focal adhesion kinase (FAK) increased from W0 to W4 whereas total mechanistic target of rapamycin (mTOR) was increased from W0 at W1 with no further significant increases at W2 and W4. These data show that FO supplementation results in discordant changes in the n-3 PUFA composition of skeletal muscle compared to blood that is associated with increases in total FAK content.     

The effect of long-term consumption of fish oil on platelet-activating factor synthesis in rat renal microsomes

The effect of consuming eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) on platelet-activating factor (PAF) biosynthesis by renal acetyl-CoA: 1-O-alkyl-sn-glycero-3-phosphocholine (lysoPAF) acetyltransferase activity was compared in rats fed diets containing fish oil (FO) or sunflower oil (SO) for 11 months. Microsomes from the FO group exhibited a significantly lower formation of [14C]PAF from [1-14C]acetyl-CoA in the absence of exogenously-added lysoPAF. There were no differences between the two groups in the generation of radioactive acylacetyl-glycerophosphocholine (GPC) upon incubation of microsomes without added lysoPAF. Upon addition of lysoPAF, the microsomal synthesis of PAF, but not acylacetyl-GPC, rose considerably. Furthermore, PAF synthesis via microsomal acetyltransferase activity in the FO-fed animals was only 40% that of the SO groups. These findings may bear potential relevance in terms of reducing PAF synthesis in association with renal pathophysiology.     

The effect of enzymatically polymerised polyphenols on CD4 binding and cytokine production in murine splenocytes

High-molecular weight polymerised polyphenols have been shown to exhibit anti-influenza virus, anti-HIV, and anti-cancer activities. The purpose of this study was to evaluate the immunomodulating activities of enzymatically polymerised polyphenols, and to clarify the underlying mechanisms of their effects. The cytokine-inducing activity of the enzymatically polymerised polyphenols derived from caffeic acid (CA), ferulic acid (FA), and p-coumaric acid (CoA) was investigated using murine splenocytes. Polymerised polyphenols, but not non-polymerised polyphenols, induced cytokine synthesis in murine splenocytes. Polymerised polyphenols induced several cytokines in murine splenocytes, with interferon-γ (IFN-γ) and granulocyte-macrophage colony-stimulating factor (GM-CSF) being the most prominent. The underlying mechanisms of the effects of the polymerised polyphenols were then studied using neutralising antibodies and fluorescent-activated cell sorting (FACS) analysis. Our results show that polymerised polyphenols increased IFN-γ and GM-CSF production in splenocytes. In addition, the anti-CD4 neutralised monoclonal antibody (mAb) inhibited polymerised polyphenol-induced IFN-γ and GM-CSF secretion. Moreover, polymerised polyphenols bound directly to a recombinant CD4 protein, and FACS analysis confirmed that interaction occurs between polymerised polyphenols and CD4 molecules expressed on the cell surface. In this study, we clearly demonstrated that enzymatic polymerisation confers immunoactivating potential to phenylpropanoic acids, and CD4 plays a key role in their cytokine-inducing activity.