Avenanthramides are bioavailable and have antioxidant activity in humans after acute consumption of an enriched mixture from oats

A randomized crossover study to assess the effect of an oat-rich diet on glycaemic control, plasma lipids and postprandial glycaemia, inflammation and oxidative stress in Type 2 diabetes

AIMS

In the UK, lifestyle intervention is first-line management in Type 2 diabetes. It is unclear what type of diet is most efficacious for improving glycaemic control. This study investigated the effects of an oat-enriched diet on glycaemic control, postprandial glycaemia, inflammation and oxidative stress compared with standard dietary advice.

METHODS

In a randomized crossover design, 27 volunteers with Type 2 diabetes, managed on diet and lifestyle only, were observed for two consecutive 8-week periods following either the oat-enriched diet or re-enforced standard dietary advice. Volunteers attended at baseline (habitual intake) and 8 and 16 weeks. Measurements included basic clinical measurements and fasted and postprandial (3-h) glucose and insulin in response to a healthy test meal. Markers of inflammation and oxidative stress, including high-sensitivity C-reactive protein, interleukin 6, interleukin 18, tumour necrosis factor-alpha, adiponectin, thiobarbituric acid reactive substances, oxygen radical antioxidant capacity, oxidized LDL and urinary isoprostanes, were also measured at fasting and in the postprandial period.

RESULTS

There were no diet-related effects on glycaemic control or glycaemic or insulinaemic responses to the test meal. Total cholesterol (5.1 ± 1.0 vs. 4.9 ± 0.8 mmol/l, P = 0.019) concentrations declined following the oat-enriched diet compared with standard dietary advice. There was a postprandial decline in adiponectin concentration (P = 0.009), but no effect of dietary intervention. None of the measures of oxidative stress or inflammation were altered by the oat-enriched diet compared with standard dietary advice.

CONCLUSION

The oat-enriched diet had a modest impact on lipid lowering, but did not impact on oxidative stress or inflammation in these volunteers with Type 2 diabetes.

Protective effect of oat bran extracts on human dermal fibroblast injury induced by hydrogen peroxide

Oat contains different components that possess antioxidant properties; no study to date has addressed the antioxidant effect of the extract of oat bran on the cellular level. Therefore, the present study focuses on the investigation of the protective effect of oat bran extract by enzymatic hydrolysates on human dermal fibroblast injury induced by hydrogen peroxide (H(2)O(2)). Kjeldahl determination, phenol-sulfuric acid method, and high-performance liquid chromatography (HPLC) analysis indicated that the enzymatic products of oat bran contain a protein amount of 71.93%, of which 97.43% are peptides with a molecular range from 438.56 to 1301.01 Da. Assays for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity indicate that oat peptide-rich extract has a direct and concentration-dependent antioxidant activity. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay and the TdT-mediated digoxigenin-dUTP nick-end labeling (TUNEL) assay for apoptosis showed that administration of H(2)O(2) in human dermal fibroblasts caused cell damage and apoptosis. Pre-incubation of human dermal fibroblasts with the Oatp for 24 h markedly inhibited human dermal fibroblast injury induced by H(2)O(2), but application oat peptides with H(2)O(2) at same time did not. Pre-treatment of human dermal fibroblasts with Oatp significantly reversed the H(2)O(2)-induced decrease of superoxide dismutase (SOD) and the inhibition of malondialdehyde (MDA). The results demonstrate that oat peptides possess antioxidant activity and are effective against H(2)O(2)-induced human dermal fibroblast injury by the enhanced activity of SOD and decrease in MDA level. Our results suggest that oat bran will have the potential to be further explored as an antioxidant functional food in the prevention of aging-related skin injury.

Chronic consumption of a wild green oat extract (Neuravena) improves brachial flow-mediated dilatation and cerebrovascular responsiveness in older adults

BACKGROUND

Heart health benefits have been attributed to regular consumption of oats. Preclinical evidence suggests that a wild green oat extract (WGOE) may improve vasodilator function, but this is yet to be evaluated in humans.

OBJECTIVE

To determine whether regular daily consumption of WGOE can influence vasodilator function in systemic and cerebral arteries.

METHODS

Thirty-seven healthy older adults (>60 years) completed a 24-week randomized, double-blind, placebo-controlled two-way crossover dietary intervention with 1500 mg/day of encapsulated WGOE or placebo. All assessments were conducted at the end of each 12-week intervention arm, after participants had fasted for at least 4 h and at least 18 h after they had taken their last dose of supplement. Flow-mediated dilatation (FMD) of the brachial artery and hypercapnia-induced increases of blood flow in the middle cerebral artery were used to measure systemic and cerebral vasodilator responsiveness (CVR), respectively.

RESULTS

Compared with placebo, WGOE supplementation increased CVR and FMD to a similar extent (42 and 41%, respectively, P < 0.01 for both). The improvements in CVR and FMD were not correlated. Resting blood pressure did not alter with supplementation. Dose and treatment duration were well tolerated by participants.

CONCLUSION

WGOE supplementation can improve vasodilator function in systemic and cerebral arteries, suggesting a potential role in the maintenance of cardiovascular health.

The potential role of phytochemicals in wholegrain cereals for the prevention of type-2 diabetes

Diets high in wholegrains are associated with a 20-30% reduction in risk of developing type-2 diabetes (T2D), which is attributed to a variety of wholegrain components, notably dietary fibre, vitamins, minerals and phytochemicals. Most phytochemicals function as antioxidants in vitro and have the potential to mitigate oxidative stress and inflammation which are implicated in the pathogenesis of T2D. In this review we compare the content and bioavailability of phytochemicals in wheat, barley, rice, rye and oat varieties and critically evaluate the evidence for wholegrain cereals and cereal fractions increasing plasma phytochemical concentrations and reducing oxidative stress and inflammation in humans. Phytochemical content varies considerably within and among the major cereal varieties. Differences in genetics and agro-climatic conditions explain much of the variation. For a number of the major phytochemicals, such as phenolics and flavanoids, their content in grains may be high but because these compounds are tightly bound to the cell wall matrix, their bioavailability is often limited. Clinical trials show that postprandial plasma phenolic concentrations are increased after consumption of wholegrain wheat or wheat bran however the magnitude of the response is usually modest and transient. Whether this is sufficient to bolster antioxidant defences and translates into improved health outcomes is still uncertain. Increased phytochemical bioavailability may be achieved through bio-processing of grains but the improvements so far are small and have not yet led to changes in clinical or physiological markers associated with reduced risk of T2D. Furthermore, the effect of wholegrain cereals and cereal fractions on biomarkers of oxidative stress or strengthening antioxidant defence in healthy individuals is generally small or nonexistent, whereas biomarkers of systemic inflammation tend to be reduced in people consuming high intakes of wholegrains. Future dietary intervention studies seeking to establish a direct role of phytochemicals in mediating the metabolic health benefits of wholegrains, and their potential for mitigating disease progression, should consider using varieties that deliver the highest possible levels of bioavailable phytochemicals in the context of whole foods and diets. Both postprandial and prolonged responses in systemic phytochemical concentrations and markers of inflammation and oxidative stress should be assessed along with changes related to health outcomes in healthy individuals as well as those with metabolic disease.

Avena sativa (Oat), a potential neutraceutical and therapeutic agent: an overview

The aim of the present review article is to summarize the available information related to the availability, production, chemical composition, pharmacological activity, and traditional uses of Avena sativa to highlight its potential to contribute to human health. Oats are now cultivated worldwide and form an important dietary staple for the people in number of countries. Several varieties of oats are available. It is a rich source of protein, contains a number of important minerals, lipids, β-glucan, a mixed-linkage polysaccharide, which forms an important part of oat dietary fiber, and also contains various other phytoconstituents like avenanthramides, an indole alkaloid-gramine, flavonoids, flavonolignans, triterpenoid saponins, sterols, and tocols. Traditionally oats have been in use since long and are considered as stimulant, antispasmodic, antitumor, diuretic, and neurotonic. Oat possesses different pharmacological activities like antioxidant, anti-inflammatory, wound healing, immunomodulatory, antidiabetic, anticholesterolaemic, etc. A wide spectrum of biological activities indicates that oat is a potential therapeutic agent.

Phytochemicals attenuating aberrant activation of β-catenin in cancer cells

Phytochemicals are a rich source of chemoprevention agents but their effects on modulating the Wnt/β-catenin signaling pathway have remained largely uninvestigated. Aberrantly activated Wnt signaling can result in the abnormal stabilization of β-catenin, a key causative step in a broad spectrum of cancers. Here we report the modulation of lithium chloride-activated canonical Wnt/β-catenin signaling by phytochemicals that have antioxidant, anti-inflammatory or chemopreventive properties. The compounds were first screened with a cervical cancer-derived stable Wnt signaling reporter HeLa cell line. Positive hits were subsequently evaluated for β-catenin degradation, suppression of β-catenin nuclear localization and down-regulation of downstream oncogenic targets of Wnt/β-catenin pathway. Our study shows a novel degradation path of β-catenin protein in HeLa cells by Avenanthramide 2p (a polyphenol) and Triptolide (a diterpene triepoxide), respectively from oats and a Chinese medicinal plant. The findings present Avenanthramide 2p as a potential chemopreventive dietary compound that merits further study using in vivo models of cancers; they also provide a new perspective on the mechanism of action of Triptolide.

Chronic effects of a wild green oat extract supplementation on cognitive performance in older adults: a randomised, double-blind, placebo-controlled, crossover trial

Background and aim: Preliminary evaluation of a wild green oat extract (WGOE) (Neuravena^® ELFA^®955, Frutarom, Switzerland) revealed an acute cognitive benefit of supplementation. This study investigated whether regular daily WGOE supplementation would result in sustained cognitive improvements. Method: A 12-week randomised, double-blind, placebo-controlled cross-over trial of WGOE supplementation (1500 mg/day) versus placebo was undertaken in 37 healthy adults aged 67 ± 0.8 years (mean ± SEM). Cognitive assessments included the Stroop colour-word test, letter cancellation, the rule-shift task, a computerised multi-tasking test battery and the trail-making task. All assessments were conducted in Week 12 and repeated in Week 24 whilst subjects were fasted and at least 18 h after taking the last dose of supplement. Result: Chronic WGOE supplementation did not affect any measures of cognition. Conclusion: It appears that the cognitive benefit of acute WGOE supplementation does not persist with chronic treatment in older adults with normal cognition. It remains to be seen whether sustained effects of WGOE supplementation may be more evident in those with mild cognitive impairment.

Constituents in purple sweet potato leaves inhibit in vitro angiogenesis with opposite effects ex vivo

OBJECTIVE

The aim of this study was to investigate the in vitro effect of polyphenols in purple sweet potato leaves (PSPLs) on angiogenesis in human umbilical vascular endothelial cells (HUVECs). The ex vivo effect was test in human serum collected from the subjects who consumed 200 g of PSPL in a low polyphenol diet versus a low polyphenol diet.

METHODS

Methanolic extract from PSPLs and human sera from subjects were treated with HUVECs and the effects of cell proliferation, migration, tube formation, and matrix metalloproteinase activity were investigated.

RESULTS

The PSPL polyphenols at 0.2 to 0.6 mM gallic acid equivalents inhibited proliferation, migration, and tube formation of vascular endothelial growth factor-treated HUVECs. Further, the activity of secreted matrix metalloproteinase-2 was decreased by at least 13.8%. However, 5% PSPL serum increased migration and tube formation of HUVECs by 110% and 56.9%, respectively, compared with serum from subjects on the low polyphenol diet. Further, the activity of matrix metalloproteinase-9 was increased by 128% in the PSPL serum.

CONCLUSION

These results suggest that PSPL polyphenols inhibited in vitro angiogenesis, but PSPL constituents might shift serum biochemistries to be more proangiogenic.

The effect of 90 day administration of a high dose vitamin B-complex on work stress

OBJECTIVE

Occupational stress is increasing in Western societies and the impact is significant at a personal, organisational and community level. The present study examined for the first time the efficacy of 3 months administration of two forms of high dose vitamin B complex on mood and psychological strain associated with chronic work stress.

METHOD

Sixty participants completed the 3-month, double-blind, randomised, placebo-controlled trial in which personality, work demands, mood, anxiety and strain were assessed.

RESULTS

After individual differences in personality and work demands were statistically controlled, the vitamin B complex treatment groups reported significantly lower personal strain and a reduction in confusion and depressed/dejected mood after 12 weeks. There were no treatment-related changes in other measures of mood and anxiety.

DISCUSSION

The results of the study are consistent with two previous studies examining multivitamin supplementation and personal (non-work) feelings of strain and suggestive of significant decreases in the experience of workplace stress after 90 day supplementation of a B multivitamin.

CONCLUSION

Given the direct and indirect costs of workplace stress, these findings point to the utility of a cost-effective treatment for the mood and psychological strain effects of occupational stress. These findings may have important personal health, organisational and societal outcomes given the rising cost and incidence of workplace stress.

Effect of chemical systemic acquired resistance elicitors on avenanthramide biosynthesis in oat (Avena sativa)

Oats produce a group of phenolic antioxidants termed avenanthramides. These metabolites are, among food crops, unique to oats and have shown, in experimental systems, certain desirable nutritional characteristics such as inhibiting atherosclerotic plaque formation and reducing inflammation. Avenanthramides occur in both the leaves and grain of oat. In the leaves they are expressed as phytoalexins in response to crown rust (Puccina coronata) infection. The experiments reported here demonstrate that avenanthramide levels in vegetative tissue can be enhanced by treatment with benzothiadiazole (BTH), an agrochemical formulated to elicit systemic acquired resistance (SAR). The response to BTH was dramatically stronger than those produced with salicylic acid treatment. The roots of BTH treated plants also showed a smaller but distinct increase in avenanthramides. The dynamics of the root avenanthramide increase was substantially slower than that observed in the leaves, suggesting that avenanthramides might be transported from the leaves.

Avenanthramides are bioavailable and accumulate in hepatic, cardiac, and skeletal muscle tissue following oral gavage in rats

Avenanthramides (AVA), polyphenols found exclusively in oats ( Avena sativa L.), may play a role in the anti-inflammatory and antiatherogenic activity of oats. The bioavailability of AVA has been demonstrated previously, but its distribution at the organ and tissue level and the extent of conjugation following ingestion have been unexplored. Synthetic AVA was administered to 24 rats by oral gavage, whereas 6 control rats received saline. AVA concentrations were measured via HPLC in plasma, liver, heart, and gastrocnemius (GAS) obtained over a 12 h period (0, 2, 4, 12 h; n = 6 at each time point). Samples were extracted with and without glucuronidase-sulfatase to assess the level of conjugation. We conclude that AVA are bioavailable to the blood circulation following oral ingestion in the rat and reach peripheral tissues where they can be taken up by various organs differentially. With AVA remaining in the organs for up to 12 h, it seems possible to maintain an increased level of AVA in the rat via repeated feedings.

Avenanthramides inhibit proliferation of human colon cancer cell lines in vitro

A high intake of whole grain foods is associated with reduced risk of colon cancer, but the mechanism underlying this protection has yet to be elucidated. Chronic inflammation and associated cyclooxygenase-2 (COX-2) expression in the colon epithelium are causally related to epithelial carcinogenesis, proliferation, and tumor growth. We examined the effect of avenanthramides (Avns), unique polyphenols from oats with anti-inflammatory properties, on COX-2 expression in macrophages, colon cancer cell lines, and on proliferation of human colon cancer cell lines. We found that Avns-enriched extract of oats (AvExO) had no effect on COX-2 expression, but it did inhibit COX enzyme activity and prostaglandin E(2) (PGE(2)) production in lipopolysaccharide-stimulated mouse peritoneal macrophages. Avns (AvExO, Avn-C, and the methylated form of Avn-C (CH3-Avn-C)) significantly inhibited cell proliferation of both COX-2-positive HT29, Caco-2, and LS174T, and COX-2-negative HCT116 human colon cancer cell lines, CH3-Avn-C being the most potent. However, Avns had no effect on COX-2 expression and PGE(2) production in Caco-2 and HT29 colon cancer cells. These results indicate that the inhibitory effect of Avns on colon cancer cell proliferation may be independent of COX-2 expression and PGE(2) production. Thus, Avns might reduce colon cancer risk through inhibition of macrophage PGE(2) production and non-COX-related antiproliferative effects in colon cancer cells. Interestingly, Avns had no effect on cell viability of confluence-induced differentiated Caco-2 cells, which display the characteristics of normal colonic epithelial cells. Our results suggest that the consumption of oats and oat bran may reduce the risk of colon cancer not only because of their high fiber content but also due to Avns, which attenuate proliferation of colonic cancer cells.

Dihydroavenanthramide D inhibits human breast cancer cell invasion through suppression of MMP-9 expression

Dihydroavenanthramide D (DHAvD) is a synthetic analog to naturally occurring avenanthramide, which is the active component of oat. Previous study demonstrates that DHAvD strongly inhibits activation of nuclear factor-kappa B (NF-κB), which is a major component in cancer cell invasion. The present study investigated whether DHAvD can modulate MMP-9 expression and cell invasion in MCF-7 human breast cancer cells. MMP-9 expression and cell invasion in response to 12-O-tetradecanoylphorbol-13-acetate (TPA) was increased, whereas these inductions were muted by DHAvD. DHAvD also suppressed activation of mitogen-activated protein kinase (MAPK), and MAPK-mediated nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) activations in TPA-treated MCF-7 cells. The results indicate that DHAvD-mediated inhibition of TPA-induced MMP-9 expression and cell invasion involves the suppression of the MAPK/NF-κB and MAPK/AP-1 pathways in MCF-7 cells. DHAvD may have potential value in breast cancer metastasis.

Chemical characterization of the avenanthramide-rich extract from oat and its effect on D-galactose-induced oxidative stress in mice

The present study was to characterize the avenanthramide-rich extract (ARE) from oat bran and assess its effect on activity and gene expression of antioxidant enzymes in D-galactose-induced oxidative-stressed mice. High-performance liquid chromatography (HPLC) analysis found that ARE had 6.07% N-(3',4'-dihydroxycinnamoyl)-5-hydroxyanthranilic acid (Bc), 4.37% N-(4'-hydroxycinnamoyl)-5-hydroxyanthranilic acid (Bp), and 5.36% N-(4'-hydroxy-3'-methoxycinnamoyl)-5-hydroxyanthranilic acid (Bf). In addition, ARE was also rich in vanillic acid (0.60%), caffeic acid (0.50%), syringic acid (0.54%), p-coumaric acid (0.16%), ferulic acid (0.08%), and sinapic acid (0.03%). Administration of D-galactose markedly lowered not only the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) but also the gene expression of manganese superoxide dismutase (SOD), copper-zinc SOD, glutathione peroxidase (GPx), and lipoprotein lipase (LPL) mRNA in mice. Administration of ARE significantly reversed the D-galactose-induced oxidative stress by increasing the activity of the antioxidant enzymes and upregulating their gene expression. This was accompanied by a significant decrease in the malondialdehyde (MDA) level in mice given ARE compared to the control. The results demonstrated that ARE possessed the antioxidant activity and was effective against D-galactose-induced oxidative stress.

New hypotheses for the health-protective mechanisms of whole-grain cereals: what is beyond fibre?

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as alpha-linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the 'whole-grain package', and the most promising ways for improving the nutritional quality of cereal products are discussed.

In vitro antioxidant activity and antigenotoxic effects of avenanthramides and related compounds

Avenanthramides are substituted N-cinnamoylanthranilic acids, with hydroxycinnamic acid and anthranilic acid moieties. These alkaloid phenols, which are unique to oats, may confer health benefits via antioxidant or other mechanisms. Synthetic avenanthramides, hydroxycinnamic acids, Tranilast, and ascorbic acid were evaluated for antioxidant activity using two assays, DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant potential), and for antigenotoxicity using the Comet assay with stressed human adenocarcinoma colon cells. Of all the compounds tested, N-(3',4'-dihydroxy-(E)-cinnamoyl)-5-hydroxyanthranilic acid (2c), an abundant oat avenanthramide, generally had the highest activity in all three assays. The drug Tranilast showed antigenotoxic effects, but not antioxidant activity, suggesting that antigenotoxicity is not dependent on antioxidant effects. Overall, results show that avenanthramides exert antioxidant and antigenotoxic activities that are comparable to those of ascorbic acid and which have the potential to exert beneficial physiological effects.

Oats supplementation prevents alcohol-induced gut leakiness in rats by preventing alcohol-induced oxidative tissue damage

We reported previously that oats supplementation prevents gut leakiness and alcoholic steatohepatitis (ASH) in our rat model of alcoholic liver disease. Because oxidative stress is implicated in the pathogenesis of both alcohol-induced gut leakiness and ASH, and because oats have antioxidant properties, we tested the hypothesis that oats protect by preventing alcohol-induced oxidative damage to the intestine. Male Sprague-Dawley rats were gavaged for 12 weeks with alcohol (starting dose of 1 g/kg increasing to 6 g/kg/day over the first 2 weeks) or dextrose, with or without oats supplementation (10 g/kg/day). Oxidative stress and injury were assessed by measuring colonic mucosal inducible nitric-oxide synthase (iNOS) (by immunohistochemistry), nitric oxide (colorimetric assay), and protein carbonylation and nitrotyrosination (immunoblotting). Colonic barrier integrity was determined by assessing the integrity of the actin cytoskeleton (immunohistochemistry) and the integrity of tight junctions (electron microscopy). Oats supplementation prevented alcohol-induced up-regulation of iNOS, nitric oxide overproduction in the colonic mucosa, and increases in protein carbonyl and nitrotyrosine levels. This protection was associated with prevention of ethanol (EtOH)-induced disorganization of the actin cytoskeleton and disruption of tight junctions. We conclude that oats supplementation attenuates EtOH-induced disruption of intestinal barrier integrity, at least in part, by inhibiting EtOH-induced increases in oxidative stress and oxidative tissue damage. This inhibition prevents alcohol-induced disruption of the cytoskeleton and tight junctions. This study suggests that oats may be a useful therapeutic agent--a nutraceutical--for the prevention of alcohol-induced oxidative stress and organ dysfunction.

Plant foods and oestrogen receptor alpha- and beta-defined breast cancer: observations from the Malmo Diet and Cancer cohort

The associations between plant foods and breast cancer incidence are inconsistent. The objective of this study was to examine prospectively the association between dietary fibre, plant foods and breast cancer, especially the association between plant food intake and oestrogen receptor (ER) alpha- and beta-defined breast cancer. Among women without prevalent cancer from the population-based prospective Malmö Diet and Cancer cohort (n = 15 773, 46-75 years at baseline), 544 women were diagnosed with incident invasive breast cancer during a mean follow-up of 10.3 years. Information on dietary habits was collected by a modified diet history method. ER status of the tumours was determined by immunohistochemistry using tissue microarray. Cox proportional hazards regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer associated with fibre and 11 plant food groups. High-fibre bread was significantly associated with a decreased breast cancer incidence (HR, 0.75; 95% CI, 0.57-0.98, for highest compared with lowest quintile). The other plant food groups were not significantly associated with breast cancer incidence. There was a tendency for a negative association for high-fibre bread among ERalpha (+) breast cancer (P for trend = 0.06) and ERbeta (+) breast cancer (P for trend = 0.06). Fried potatoes were statistically significantly associated with increased risk of ERbeta (-) breast cancer (P = 0.01). This study suggests that different plant foods may be differently associated with breast cancer, with fibre-rich bread showing an inverse association. We did not observe strong evidence for differences in incidence according to the ERalpha and ERbeta status of breast cancer.

Avenanthramides, polyphenols from oats, inhibit IL-1beta-induced NF-kappaB activation in endothelial cells

The chronic inflammation of arterial walls is associated with the development of atherosclerosis. Earlier we reported that avenanthramide (Avn)s-enriched extract of oats (AvnsO) significantly suppressed interleukin (IL)-1beta-stimulated secretion of proinflammatory cytokines, such as IL-6, IL-8, and MCP-1, by human aortic endothelial cells (HAEC). The main objective of the current study was to determine if the mechanism of inhibitory effect of these polyphenols from oats on the expression of proinflammatory cytokines is mediated through modulation of nuclear factor kappaB (NF-kappaB)-dependent transcription. Confluent HAEC monolayers were treated for 24 h with AvnsO, and synthetically prepared Avn-c suppressed IL-beta-stimulated activation of NF-kappaB in a concentration-dependent manner. CH3-Avn-c, a synthetically prepared methyl ester derivative of Avn-c with a high biological potency, significantly and dose dependently decreased mRNA expression and secretion of IL-6, IL-8, and MCP-1 by HAEC as determined by real-time RT-PCR and ELISA, and it inhibited IL-1beta- and TNFalpha-stimulated NF-kappaB activation as determined by a NF-kappaB DNA binding assay and a NF-kappaB luciferase reporter assay. AvnsO and Avn-c as well as CH3-Avn-c also inhibited the NF-kappaB-dependent reporter gene expression activated by TNFR-associated factor 2 and 6 (TRAF2, TRAF6) and NFkappaB-inducing kinase (NIK). CH3-Avn-c also significantly and dose dependently decreased the phosphorylation level of IkappaB kinase (IKK) and IkappaB, and prevented IkappaB degradation as measured by Western blotting. In addition, CH3-Avn-c markedly increased the overall levels of high mass ubiquitin-conjugated protein levels while it mildly inhibited proteasome activity. These observations suggest that Avns, unique polyphenols from oats, decrease the expression of endothelial proinflammatory cytokines at least in part through inhibition of NF-kappaB activation by inhibiting the phosphorylation of IKK and IkappaB, and by suppressing proteasome activity.

State of the Art Reviews: The Oatmeal-Cholesterol Connection: 10 Years Later

Ten years have passed since the Food and Drug Administration (FDA) completed their review of the literature pertaining to the consumption of whole-oat sources of soluble fiber and a reduction in blood cholesterol concentrations. Since that time, data have continued to accumulate regarding oat-soluble fiber consumption, cholesterol, and other physiologic vectors related to cardiovascular health. The objective of this review was to compare the findings of more contemporary analyses of the oat and cholesterol-reduction literature to determine if newer information is consistent with the original conclusion reached by the FDA. A number of formal assessments have been conducted subsequent to the FDA review, and virtually all have reached the same conclusion, namely, consumption of oats and oat-based products significantly reduces total cholesterol and low-density lipoprotein cholesterol concentrations without adverse effects on high-density lipoprotein cholesterol or triglyceride concentrations. In addition, a number of new insights about the potential benefits of oats have emerged over the past 10 years. These more recent data indicate that including oats and oat-based products as part of a lifestyle management program may confer health benefits that extend beyond total cholesterol and low-density lipoprotein cholesterol reduction.

State of the Art Reviews: The Oatmeal-Cholesterol Connection: 10 Years Later

Ten years have passed since the Food and Drug Administration (FDA) completed their review of the literature pertaining to the consumption of whole-oat sources of soluble fiber and a reduction in blood cholesterol concentrations. Since that time, data have continued to accumulate regarding oat-soluble fiber consumption, cholesterol, and other physiologic vectors related to cardiovascular health. The objective of this review was to compare the findings of more contemporary analyses of the oat and cholesterol-reduction literature to determine if newer information is consistent with the original conclusion reached by the FDA. A number of formal assessments have been conducted subsequent to the FDA review, and virtually all have reached the same conclusion, namely, consumption of oats and oat-based products significantly reduces total cholesterol and low-density lipoprotein cholesterol concentrations without adverse effects on high-density lipoprotein cholesterol or triglyceride concentrations. In addition, a number of new insights about the potential benefits of oats have emerged over the past 10 years. These more recent data indicate that including oats and oat-based products as part of a lifestyle management program may confer health benefits that extend beyond total cholesterol and low-density lipoprotein cholesterol reduction.