Bilberry Abstracts 2

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Bilberry juice modulates plasma concentration of NF-kappaB related inflammatory markers in subjects at increased risk of CVD.
            (Karlsen et al., 2010) Download
PURPOSE:  Bilberries are abundant in polyphenols. Dietary polyphenols have been associated with strategies for prevention and treatment of chronic inflammatory diseases. We investigated the effect of bilberry juice on serum and plasma biomarkers of inflammation and antioxidant status in subjects with elevated levels of at least one risk factor for cardiovascular disease (CVD). METHODS:  In a randomized controlled trial, participants consumed either bilberry juice (n = 31) or water (n = 31) for 4 weeks. RESULTS:  Supplementation with bilberry juice resulted in significant decreases in plasma concentrations of C-reactive protein (CRP), interleukin (IL)-6, IL-15, and monokine induced by INF-gamma (MIG). Unexpectedly, an increase in the plasma concentration of tumor nuclear factor-alpha (TNF-alpha) was observed in the bilberry group. CRP, IL-6, IL15, MIG, and TNF-alpha are all target genes of nuclear factor- kappa B (NF-kappaB), -a transcription factor that is crucial in orchestrating inflammatory responses. Plasma quercetin and p-coumaric acid increased in the bilberry group, otherwise no differences were observed for clinical parameters, oxidative stress or antioxidant status. Furthermore, we studied the effect of polyphenols from bilberries on lipopolysaccharide (LPS)-induced NF-kappaB activation in a monocytic cell line. We observed that quercetin, epicatechin, and resveratrol inhibited NF-kappaB activation. CONCLUSIONS:  These findings suggest that supplementation with bilberry polyphenols may modulate the inflammation processes. Further testing of bilberry supplementation as a potential strategy in prevention and treatment of chronic inflammatory diseases is warranted.


 

Effects of dietary supplementation with a combination of fish oil, bilberry extract, and lutein on subjective symptoms of asthenopia in humans.
            (Kawabata and Tsuji, 2011) Download
The aim of this study was to determine the effects of dietary supplementation with a combination of fish oil, bilberry extract, and lutein on subjective symptoms of asthenopia in humans by a double- blind, randomized, parallel-group, and placebo-controlled trial. In the Active group, eleven subjects ingested a supplement containing omega-3 fatty acid-rich fish oil (docosahexaenoic acid 783 mg/day, eicosapentaenoic acid 162 mg/day), bilberry extract (anthocyanidin 59 mg/day), and lutein (17.5 mg/day) in soft gel capsule form, every day for 4 weeks. In the Placebo group, nine subjects ingested placebo capsules. Before and after supplementation, subjects completed a questionnaire to determine their asthenopia symptoms and were also assessed for mental fatigue symptom by the visual analog scale (VAS) test. Asthenopia symptoms such as "stiff shoulder, low back pain", "frustration", "dry-eye", and "stuffy head" were improved in the Active group. Furthermore, a score of mental fatigue was improved after 4 weeks of supplementation, and no side effects were observed after the 4-week supplementation and a 2-week washout period in the Active group. These results suggest that dietary supplementation with the combination of omega-3 fatty acid-rich fish oil, bilberry extract, and lutein may safely improve subjective symptoms of asthenopia and mental fatigue in humans.

Anti-hyperglycemic effect of Vaccinium arctostaphylos in type 2 diabetic patients: a randomized controlled trial.
            (Kianbakht et al., 2013) Download
BACKGROUND:  Type 2 diabetes mellitus is a common disease. Preliminary data indicate that Vaccinium arctostaphylos L. (Caucasian whortleberry) has a potential effect in glycemic control. Thus, the efficacy and safety of a standardized whortleberry fruit hydroalcoholic extract in the treatment of type 2 diabetic patients were studied. METHODS:  This randomized double-blind placebo-controlled clinical trial consisted of 37 patients aged 40-60 years with type 2 diabetes who were resistant to conventional oral anti-hyperglycemic drugs. The patients were treated with the whortleberry fruit hydroalcoholic extract (1 capsule = 350 mg, every 8 h for 2 months) in combination with anti-hyperglycemic drugs, and the effects on the blood levels of fasting glucose, 2-hour postprandial glucose, glycosylated hemoglobin (HbA1c), and liver/kidney function were tested, evaluated, and compared with a placebo group (n = 37). RESULTS:  The extract significantly lowered the blood levels of fasting glucose, 2-h postprandial glucose, and HbA1c (p = 0.007, p <0.001, and p = 0.005, respectively) without any significant effects on the liver/kidney function (p >0.05) compared with placebo at the end. No adverse effects were reported. CONCLUSION:  Whortleberry may safely improve glycemic control in type 2 diabetic patients.

Bilberries reduce low-grade inflammation in individuals with features of metabolic syndrome.
            (Kolehmainen et al., 2012) Download
SCOPE:  Low-grade inflammation is a hallmark of cardiometabolic risk. Bilberries (Vaccinium myrtillus) are rich in polyphenols with potential anti-inflammatory properties. We studied the impact of bilberries on inflammation and gene expression profile in peripheral blood mononuclear cells in subjects with metabolic syndrome. METHODS AND RESULTS:  In randomized, controlled dietary intervention, the participants consumed either a diet rich in bilberries (n = 15) or a control diet (n = 12). The bilberry group consumed daily an equivalent dose of 400 g fresh bilberries, while the control group maintained their habitual diet. No differences were found between the groups in body weight, glucose, or lipid metabolism, but bilberry supplementation tended to decrease serum high-sensitivity C-reactive protein, IL-6, IL-12, and LPS concentrations. An inflammation score was significantly different between the groups (p = 0.024). In transcriptomics analyses (three participants with improved oral glucose tolerance test in the bilberry group), Toll-like receptor signaling, cytoplasmic ribosomal proteins, and B-cell receptor signaling pathways were differently regulated. QPCR analyses (n = 13 and 11 in the bilberry and control groups, respectively) showed decreased expression of MMD and CCR2 transcripts associated with monocyte and macrophage function associated genes. CONCLUSION:  Regular bilberry consumption may reduce low-grade inflammation indicating decreased cardiometabolic risk in the long term.

Modulation of Nrf2-dependent gene transcription by bilberry anthocyanins in vivo.
            (Kropat et al., 2013) Download
In a human pilot intervention study (healthy + ileostomy probands), the questions were addressed whether in vivo consumption of an anthocyanin-rich bilberry (Vaccinium myrtillius L.) pomace extract (BE) affects (i) the transcription of Nrf2-dependent genes in peripheral blood mononuclear cells (PBMC), indicative for systemic effects, and (ii) the level of oxidative DNA damage in these cells. In healthy test subjects transcripts of NAD(P)H quinone oxidoreductase 1 (NQO1) were significantly elevated throughout the observation period (1-8 h), whereas transcription of heme oxygenase 1 (HO-1) and Nrf2 was significantly decreased. NQO1 and HO-1 transcription remained unchanged in the ileostomy probands, whereas Nrf2-transcription was suppressed in both groups. Decrease in oxidative DNA damage was observed 2 h after BE consumption again only in healthy subjects. In vitro studies using a reporter gene approach (CHO) and qPCR (HT29) indicate that not the intact anthocyanins/anthocyanidins are the activating constituents but the intestinal degradation product phloroglucinol aldehyde (PGA). Taken together, consumption of anthocyanin-rich BE was found to modulate Nrf2-dependent gene expression in PBMCs indicative for systemic activity. Limitation of the effect to healthy test subjects suggests a role of colonic processes for bioactivity, supported by the results on Nrf2-activating properties of the intestinal anthocyanin degradation product PGA.

Polyphenol-rich juices reduce blood pressure measures in a randomised controlled trial in high normal and hypertensive volunteers.
            (Tjelle et al., 2015) Download
Intake of fruits and berries may lower blood pressure (BP), most probably due to the high content of polyphenols. In the present study, we tested whether consumption of two polyphenol-rich juices could lower BP. In a randomised, double-blinded, placebo-controlled trial of 12 weeks, 134 healthy individuals, aged 50-70 years, with high normal range BP (130/85-139/89 mmHg, seventy-two subjects) or stage 1-2 hypertension (140/90-179/109 mmHg, sixty-two subjects), were included. They consumed 500 ml/d of one of either (1) a commercially available polyphenol-rich juice based on red grapes, cherries, chokeberries and bilberries; (2) a juice similar to (1) but enriched with polyphenol-rich extracts from blackcurrant press-residue or (3) a placebo juice (polyphenol contents 245·5, 305·2 and 76 mg/100 g, respectively). Resting BP was measured three times, with a 1 min interval, at baseline and after 6 and 12 weeks of intervention. Systolic BP significantly reduced over time (6 and 12 weeks, respectively) in the pooled juice group compared with the placebo group in the first of the three measurements, both for the whole study group (6·9 and 3·4 mmHg; P= 0·01) and even more pronounced in the hypertensive subjects when analysed separately (7·3 and 6·8 mmHg; P= 0·04). The variation in the BP measurements was significantly reduced in the pooled juice group compared with the placebo group (1·4 and 1·7 mmHg; P= 0·03). In conclusion, the present findings suggest that polyphenol-rich berry juice may contribute to a BP- and BP variability lowering effect, being more pronounced in hypertensive than in normotensive subjects.


 

A CONSORT-compliant, randomized, double-blind, placebo-controlled pilot trial of purified anthocyanin in patients with nonalcoholic fatty liver disease.
            (Zhang et al., 2015) Download
Nonalcoholic fatty liver disease (NAFLD) is a common liver disease that can progress to cirrhosis and liver failure. Anthocyanin, a member of the flavonoid family, has been shown to ameliorate NAFLD-associated pathologies in rodents.The aim of this CONSORT-compliant pilot study is to evaluate the effects of anthocyanin supplementation on insulin resistance and liver injury biomarkers in patients with NAFLD.A total of 74 subjects with NAFLD were divided into 2 groups in this double-blind, randomized study. Patients received either purified anthocyanin (320 mg/d) derived from bilberry and black currant or placebo for 12 weeks. Diet, physical activity, anthropometric parameters, glucose tolerance, and a set of biomarkers related to NAFLD were evaluated before and after intervention.No significant differences were observed in nutrient intake, physical activity, anthropometric parameters, or plasma lipid profile between patients receiving anthocyanin or placebo. Compared to controls, the anthocyanin group exhibited significant decreases (P < 0.05, all comparisons) in plasma alanine aminotransferase (-19.1% vs 3.1%), cytokeratin-18 M30 fragment (-8.8% vs 5.6%) and myeloperoxidase (-75.0% vs -44.8%). Significant decreases from baseline in fasting blood glucose and homeostasis model assessment for insulin resistance were observed in the anthocyanin group; however, these differences were not significant relative to placebo controls. In addition, the oral glucose tolerance test indicated that anthocyanin supplementation significantly decreased the 2-hour loading glucose level compared to control (-18.7% vs -3.8%, P = 0.02).A 12-week supplement of purified anthocyanin improved insulin resistance, indicators of liver injury, and clinical evolution in NAFLD patients. Further studies are warranted to determine the clinical applications of anthocyanin in NAFLD.This trial was registered at clinicaltrials.gov as NCT01940263.

Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individuals.
            (Zhu et al., 2011) Download
BACKGROUND:  Anthocyanins have been shown to improve endothelial function in animal models. However, whether these compounds have similar beneficial effects in humans is largely unknown. METHODS:  In a short-term crossover study, 12 hypercholesterolemic individuals were given oral anthocyanins (320 mg) isolated from berries or placebo. Brachial artery flow-mediated dilation (FMD) was assessed before and after the intervention. In a long-term intervention trial (12 weeks), 150 hypercholesterolemic individuals were given anthocyanins (320 mg/day, n = 75) or placebo (n = 75), after which we measured FMD, plasma cGMP, and other serum biomarkers. Another short-term intervention was conducted in the presence of NO-cGMP inhibitors in 6 people and in a rat aortic ring model (n = 8). RESULTS:  Significant increases of FMD from 8.3% (0.6%) at baseline to 11.0% (0.8%) at 1 h and 10.1% (0.9%) at 2 h were observed after short-term anthocyanin consumption, concomitantly with increases of plasma anthocyanin concentrations (P < 0.05). In the study participants who received long-term anthocyanin intervention, compared with the control group, we observed significant increases in the FMD (28.4% vs 2.2%), cGMP (12.6% vs -1.2%), and HDL-cholesterol concentrations, but decreases in the serum soluble vascular adhesion molecule-1 and LDL cholesterol concentrations (P < 0.05). The changes in the cGMP and HDL cholesterol concentrations positively correlated with FMD in the anthocyanin group (P < 0.05). In the presence of NO-cGMP inhibitors, the effects of anthocyanin on endothelial function were abolished in human participants and in a rat aortic ring model. CONCLUSIONS:  Anthocyanin supplementation improves endothelium-dependent vasodilation in hypercholesterolemic individuals. This effect involves activation of the NO-cGMP signaling pathway, improvements in the serum lipid profile, and decreased inflammation.


 

References

Karlsen, A, et al. (2010), ‘Bilberry juice modulates plasma concentration of NF-kappaB related inflammatory markers in subjects at increased risk of CVD.’, Eur J Nutr, 49 (6), 345-55. PubMed: 20119859
Kawabata, F and T Tsuji (2011), ‘Effects of dietary supplementation with a combination of fish oil, bilberry extract, and lutein on subjective symptoms of asthenopia in humans.’, Biomed Res, 32 (6), 387-93. PubMed: 22199129
Kianbakht, S, B Abasi, and FH Dabaghian (2013), ‘Anti-hyperglycemic effect of Vaccinium arctostaphylos in type 2 diabetic patients: a randomized controlled trial.’, Forsch Komplementmed, 20 (1), 17-22. PubMed: 23727759
Kolehmainen, M, et al. (2012), ‘Bilberries reduce low-grade inflammation in individuals with features of metabolic syndrome.’, Mol Nutr Food Res, 56 (10), 1501-10. PubMed: 22961907
Kropat, C, et al. (2013), ‘Modulation of Nrf2-dependent gene transcription by bilberry anthocyanins in vivo.’, Mol Nutr Food Res, 57 (3), 545-50. PubMed: 23349102
Tjelle, TE, et al. (2015), ‘Polyphenol-rich juices reduce blood pressure measures in a randomised controlled trial in high normal and hypertensive volunteers.’, Br J Nutr, 114 (7), 1054-63. PubMed: 26227795
Zhang, PW, et al. (2015), ‘A CONSORT-compliant, randomized, double-blind, placebo-controlled pilot trial of purified anthocyanin in patients with nonalcoholic fatty liver disease.’, Medicine (Baltimore), 94 (20), e758. PubMed: 25997043
Zhu, Y, et al. (2011), ‘Purified anthocyanin supplementation improves endothelial function via NO-cGMP activation in hypercholesterolemic individuals.’, Clin Chem, 57 (11), 1524-33. PubMed: 21926181