The fractions of monomeric catechins and the fractions of dimeric and trimeric procyanidins were extracted and concentrated from wild berries of Vaccinium species to study their antioxidant ...activities. The compositions of the fractions were analyzed using high-performance liquid chromatography combined with diode-array and electrospray ionization mass spectrometric detection. Rare A-type dimers and trimers were identified as the predominant procyanidins in wild lingonberry, cranberry, bilberry, and bog whortleberry. Lingonberry and cranberry catechin and procyanidin fractions as well as bog whortleberry catechin fraction were good scavengers of radicals in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and more efficient than the respective bilberry fractions. Bog whortleberry procyanidin fraction was less active, this being mainly due to the lower content of these compounds. Fractions from lingonberry, cranberry, and bilberry were equally efficient in inhibiting the oxidation of methyl linoleate emulsion, but differences among the berries were found in their abilities to inhibit low-density lipoprotein (LDL) oxidation. Catechins, the monomers, exhibited comparable activity to the fractions containing dimers and trimers in inhibiting the oxidation of methyl linoleate emulsion and human LDL. Bog whortleberry catechins were excellent antioxidants toward the oxidation of human LDL. Radical scavenging and antioxidant activities of Vaccinium berry fractions were attributable to the their composition of catechins and procyanidins. In conclusion, Vaccinium catechins as well as dimeric and trimeric procyanidins provide substantial antioxidant protection. Keywords: Food analysis; berries; phenolic compounds; HPLC; proanthocyanidins; antioxidants; radical scavengers; LDL
The amounts of quercetin, myricetin, and kaempferol aglycons in 25 edible berries were analyzed by an optimized RP-HPLC method with UV detection and identified with diode array and electrospray ...ionization mass spectrometry detection. Sixteen species of cultivated berries and nine species of wild berries were collected in Finland in 1997. Quercetin was found in all berries, the contents being highest in bog whortleberry (158 mg/kg, fresh weight), lingonberry (74 and 146 mg/kg), cranberry (83 and 121 mg/kg), chokeberry (89 mg/kg), sweet rowan (85 mg/kg), rowanberry (63 mg/kg), sea buckthorn berry (62 mg/kg), and crowberry (53 and 56 mg/kg). Amounts between 14 and 142 mg/kg of myricetin were detected in cranberry, black currant, crowberry, bog whortleberry, blueberries, and bilberry. Kaempferol was detected only in gooseberries (16 and 19 mg/kg) and strawberries (5 and 8 mg/kg). Total contents of these flavonols (100−263 mg/kg) in cranberry, bog whortleberry, lingonberry, black currant, and crowberry were higher than those in the commonly consumed fruits or vegetables, except for onion, kale, and broccoli. Keywords: Flavonoid; flavonol; quercetin; myricetin; kaempferol; berry; fruit; HPLC
Aim
Nutrition contributes to increased adiposity, but it remains to be determined whether high fat rather than Western diet exacerbates the development of obesity and other characteristics of ...metabolic syndrome and vascular function.
Methods
We studied the effects of high fat (45% kcal) diet (HFD) and equal caloric Western diet (WD) high in fat, sucrose and cholesterol for 8 weeks in male C57B1/6N mice.
Results
Mice fed with HFD and WD showed substantially higher body adiposity (body fat %) compared with control mice receiving low fat (10%) diet (LFD). However, total body weight was higher only in HFD mice compared with other groups. The amount of liver triglycerides, cholesterol and oxidative damage was higher in WD mice compared with mice on LFD. There were no significant differences in fasting blood glucose or serum insulin, serum or muscle triglycerides, glucose tolerance or systolic blood pressure between the groups, but serum free fatty acids were increased in HFD mice compared with LFD. Increased levels of tissue and serum diene conjugation as a marker of oxidative stress were evident especially in WD mice. The endothelium‐dependent relaxations were significantly impaired in the small mesenteric arteries of HFD mice, but not in the aorta. Maximal relaxations correlated negatively with body adiposity in WD but not in HFD mice.
Conclusions
The major finding in the present study is that without changing body weight, Western diet induces marked whole‐body oxidative stress and elevates body adiposity, which associates with the endothelial function of resistance arteries.
Heart failure with preserved ejection fraction (HFpEF) constitutes a clinical syndrome in which the diagnostic criteria of heart failure are not accompanied by gross disturbances of systolic ...function, as assessed by ejection fraction. In turn, under most circumstances, diastolic function is impaired. Although it now represents over 50 % of all patients with heart failure, the mechanisms of HFpEF remain understood, precluding effective therapy. Understanding the pathophysiology of HFpEF has been restricted by both limited access to human myocardial biopsies and by the lack of animal models that fully mimic human pathology. Animal models are valuable research tools to clarify subcellular and molecular mechanisms under conditions where the comorbidities and other confounding factors can be precisely controlled. Although most of the heart failure animal models currently available represent heart failure with reduced ejection fraction, several HFpEF animal models have been proposed. However, few of these fulfil all the features present in human disease. In this review we will provide an overview of the currently available models to study HFpEF from rodents to large animals as well as present advantages and disadvantages of these models.
The mechanisms that regulate bone blood flow (BBF) in humans are largely unknown. Animal studies suggest that nitric oxide (NO) could be involved, and in this study, we investigated the effects of ...inhibition of nitric oxide synthase (NOS) alone and in combination with inhibition of cyclooxygenase (COX) enzyme, thus prostaglandin (PG) synthesis on femoral bone marrow blood flow by positron emission tomography in healthy young men at rest and during one‐leg dynamic exercise. In an additional group of healthy men, the role of adenosine (ADO) in the regulation of BBF during exercise was investigated by use of an adenosine receptor blocker (aminophylline). Inhibitors were directly infused into the femoral artery. Resting BBF was 1.1 ± 0.4 mL 100 g−1min−1 and increased to almost sixfold in response to exercise (6.3 ± 1.5 mL 100 g−1 min−1). Inhibition of NOS reduced BBF at rest to 0.7 ± 0.3 mL 100 g−1 min−1 (P = .036), but did not affect BBF significantly during exercise (5.5 ± 1.4 mL 100 g−1 min−1, P = .25). On the other hand, while combined NOS and COX inhibition did not cause any further reduction of blood flow at rest (0.6 ± 0.2 mL 100 g−1min−1), the combined blockade reduced BBF during exercise by ~21%, to 5.0 ± 1.8 mL 100 g−1 min−1 (P = .014). Finally, the ADO inhibition during exercise reduced BBF from 5.5 ± 1.9 mL 100 g−1 min−1 to 4.6 ± 1.2 mL 100 g−1 min−1 (P = .045). In conclusion, our results support the view that NO is involved in controlling bone marrow blood flow at rest, and NO, PG, and ADO play important roles in controlling human BBF during exercise.
We tested the hypothesis that baseline cardiac autonomic function and its acute response to all-out interval exercise explains individual fitness responses to high-intensity interval training (HIT). ...Healthy middle-aged sedentary men performed HIT (n=12, 4-6×30 s of all-out cycling efforts with 4-min recovery) or aerobic training (AET, n=9, 40-60 min at 60% of peak workload in exercise test Loadpeak), comprising 6 sessions within 2 weeks. Low (LF) and high frequency (HF) power of R-R interval oscillation were analyzed from data recorded at supine and standing position (5+5 min) every morning during the intervention. A significant training effect (p< 0.001), without a training*group interaction, was observed in Loadpeak and peak oxygen consumption (VO2peak). Pre-training supine LF/HF ratio, an estimate of sympathovagal balance, correlated with training outcome in Loadpeak (Spearman's rho rs=-0.74, p=0.006) and VO2peak (rs=- 0.59, p=0.042) in the HIT but not the AET group. Also, the mean change in the standing LF/HF ratio in the morning after an acute HIT exercise during the 1(st) week of intervention correlated with training response in Loadpeak (rs=- 0.68, p=0.014) and VO2peak (rs=-0.60, p=0.039) with HIT but not with AET. In conclusion, pre-training cardiac sympathovagal balance and its initial alterations in response to acute HIT exercise were related to fitness responses to short-term HIT.
α-Lactalbumin (α-La), a major milk whey protein, is comprised of several amino acids prone to metal-catalyzed oxidation (MCO) typical in processing and during storage of foods. New tools are needed ...for the detection of characteristic oxidation products especially from tryptophan and cysteine that often remain unrecognized when using the traditional methods of carbonyl formation monitoring. In this study, the oxidative changes in α-La were investigated through tryptic digestion and collection of 3 descriptive peptides fitted into a metal-catalyzed oxidation (Fenton reaction) model. The peptide samples were oxidized at +37 °C for 14 d and explored with liquid chromatography-quadrupole ion trap-mass spectrometer (LC-MS
). The fractionated α-La peptides were valyl-glycyl-isoleucyl-asparaginyl-tyrosyl-tryptophyl-leucyl-alanyl-histidyl-lysine (VGINYWLAHK), leucyl-aspartyl-glutaminyl-tryptophyl-leucyl-cysteinyl-glutamyl-lysine (LDQWLCEK), and tryptophyl
-leucyl-alanyl-histidyl-lysyl-alanyl-leucyl-cysteine (W
LAHKALC). Oxidation of several amino acids, such as cysteine, histidine, lysine, and tryptophan was observed. In the peptide LDQWLCEK, cysteine was rapidly trioxidized to sulfonic acid, followed by other amino acid side chains as secondary oxidation sites. Tryptophan oxidation was more pronounced in the peptides W
LAHKALC and VGINYWLAHK, and also formation of the harmful N-formylkynurenine was observed. As a conclusion, several stable and promising oxidation markers are proposed for α-La, which could be implemented in the evaluation of quality and safety of dairy protein-containing products.
The antioxidant activity of phenolic compounds present in berries was investigated by two copper-catalyzed in vitro oxidation assays: human low-density lipoproteins (LDL) and lecithin liposomes. The ...amount of total phenolics varied between 617 and 4350 mg/kg in fresh berries, as gallic acid equivalents (GAE). In LDL at 10 μM GAE, berry extracts inhibited hexanal formation in the order: blackberries > red raspberries > sweet cherries > blueberries > strawberries. In lecithin liposomes, the extracts inhibited hexanal formation in the order: sweet cherries > blueberries > red raspberries > blackberries > strawberries. Red raspberries were more efficient than blueberries in inhibiting hydroperoxide formation in lecithin liposomes. HPLC analyses showed high anthocyanin content in blackberries, hydroxycinnamic acid in blueberries and sweet cherries, flavonol in blueberries, and flavan-3-ol in red raspberries. The antioxidant activity for LDL was associated directly with anthocyanins and indirectly with flavonols, and for liposome it correlated with the hydroxycinnamate content. Berries thus contribute a significant source of phenolic antioxidants that may have potential health effects. Keywords: Berries; antioxidants; LDL oxidation; liposomes; flavonoids; hydroxycinnamates; anthocyanins; flavan-3-ols; flavonols
α‐Lactalbumin (α‐La), a major milk whey protein, is comprised of several amino acids prone to metal‐catalyzed oxidation (MCO) typical in processing and during storage of foods. New tools are needed ...for the detection of characteristic oxidation products especially from tryptophan and cysteine that often remain unrecognized when using the traditional methods of carbonyl formation monitoring. In this study, the oxidative changes in α‐La were investigated through tryptic digestion and collection of 3 descriptive peptides fitted into a metal‐catalyzed oxidation (Fenton reaction) model. The peptide samples were oxidized at +37 °C for 14 d and explored with liquid chromatography–quadrupole ion trap‐mass spectrometer (LC–MSn). The fractionated α‐La peptides were valyl‐glycyl‐isoleucyl‐asparaginyl‐tyrosyl‐tryptophyl‐leucyl‐alanyl‐histidyl‐lysine (VGINYWLAHK), leucyl‐aspartyl‐glutaminyl‐tryptophyl‐leucyl‐cysteinyl‐glutamyl‐lysine (LDQWLCEK), and tryptophyl+16‐leucyl‐alanyl‐histidyl‐lysyl‐alanyl‐leucyl‐cysteine (W+16LAHKALC). Oxidation of several amino acids, such as cysteine, histidine, lysine, and tryptophan was observed. In the peptide LDQWLCEK, cysteine was rapidly trioxidized to sulfonic acid, followed by other amino acid side chains as secondary oxidation sites. Tryptophan oxidation was more pronounced in the peptides W+16LAHKALC and VGINYWLAHK, and also formation of the harmful N‐formylkynurenine was observed. As a conclusion, several stable and promising oxidation markers are proposed for α‐La, which could be implemented in the evaluation of quality and safety of dairy protein‐containing products.
Practical Application
The results contribute to a better understanding of oxidative deterioration of essential amino acids in milk whey protein. Monitoring the formation of the proposed α‐lactalbumin oxidation markers could benefit in the evaluation of whey protein nutritional and technological quality. The results may also be applied to safety evaluations of protein‐containing foods, including protein‐rich food supplements marketed for sports nutrition.
Objective Sedentary behaviour may contribute to the development of obesity. We investigated the relations between different types of sedentary behaviour and adiposity markers in a well-characterised ...adult population after controlling for a wide range of potential confounders. Design Cross-sectional study. Setting The Cardiovascular Risk in Young Finns Multicenter Study. Participants Sedentary time (TV viewing, computer time, reading, music/radio listening and other relaxation) was assessed with a questionnaire for 1084 women and 909 men aged 30–45 years. Other study variables included occupational and leisure-time physical activity, sleep duration, socioeconomic status, smoking, alcohol consumption, energy intake, adherence to the recommended diet, multiple individual food items, age and genetic variants associated with body mass index (BMI). Primary outcome measures BMI in kg/m2 and waist circumference (WC in cm). Results Of the different sedentary behaviour types, TV viewing was most consistently related to higher BMI and WC, both in men and women. One additional daily TV hour was associated with a 1.81±0.44 cm larger WC in women and 2 cm±0.44 cm in men (both p<0.0001). The association with TV was diluted, but remained highly significant after adjustments with all measured covariates, including several potentially obesogenic food items associated with TV viewing. The intakes of food items such as sausage, beer and soft drinks were directly associated with TV viewing, while the intakes of oat and barley, fish, and fruits and berries were associated indirectly. After these adjustments, non-TV sedentary behaviour remained associated with adiposity indices only in women. Conclusions Out of the different types of sedentary behaviour, TV viewing was most consistently associated with adiposity markers in adults. Partial dilution of these associations after adjustments for covariates suggests that the obesogenic effects of TV viewing are partly mediated by other lifestyle factors.
PDF
