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1.
Flavonoids are attracting increasing attention due to their antioxidant, cardioprotective, and immunomodulatory properties. Nevertheless, little is known about their role in exercise performance in association with immune function. This systematic review firstly aimed to shed light on the ergogenic potential of flavonoids. A search strategy was run using SCOPUS database. The returned studies were screened by prespecified eligibility criteria, including intervention lasting at least one week and performance objectively quantified, among others. Fifty-one studies (54 articles) met the inclusion criteria, involving 1288 human subjects, either physically untrained or trained. Secondly, we aimed to associate these studies with the immune system status. Seventeen of the selected studies (18 articles) assessed changes in the immune system. The overall percentage of studies reporting an improved exercise performance following flavonoid supplementation was 37%, the proportion being 25% when considering quercetin, 28% for flavanol-enriched extracts, and 54% for anthocyanins-enriched extracts. From the studies reporting an enhanced performance, only two, using anthocyanin supplements, focused on the immune system and found certain anti-inflammatory effects of these flavonoids. These results suggest that flavonoids, especially anthocyanins, may exert beneficial effects for athletes’ performances, although further studies are encouraged to establish the optimal dosage and to clarify their impact on immune status.  相似文献   
2.
Ageing is associated with postprandial muscle vascular and metabolic dysfunction, suggesting vascular modifying interventions may be of benefit. Reflecting this, we investigated the impact of acute cocoa flavanol (450–500 mg) intake (versus placebo control) on vascular (via ultrasound) and glucose/insulin metabolic responses (via arterialised/venous blood samples and ELISA) to an oral nutritional supplement (ONS) in twelve healthy older adults (50% male, 72 ± 4 years), in a crossover design study. The cocoa condition displayed significant increases in m. vastus lateralis microvascular blood volume (MBV) in response to feeding at 180 and 240-min after ONS consumption (baseline: 1.00 vs. 180 min: 1.09 ± 0.03, p = 0.05; 240 min: 1.13 ± 0.04, p = 0.002), with MBV at these timepoints significantly higher than in the control condition (p < 0.05). In addition, there was a trend (p = 0.058) for MBV in m. tibialis anterior to increase in response to ONS in the cocoa condition only. Leg blood flow and vascular conductance increased, and vascular resistance decreased in response to ONS (p < 0.05), but these responses were not different between conditions (p > 0.05). Similarly, glucose uptake and insulin increased in response to ONS (p < 0.05) comparably between conditions (p > 0.05). Thus, acute cocoa flavanol supplementation can potentiate oral feeding-induced increases in MBV in older adults, but this improvement does not relay to muscle glucose uptake.  相似文献   
3.
This study identified major phenolic compounds of the tucum-do-cerrado (Bactris setosa) peel, as well as antioxidant activity and total phytochemical compound concentration of different extracts of the peel and pulp of this fruit. Phenolic compounds of the different extracts of tucum-do-cerrado peel were identified and quantified using a high-performance liquid chromatography system coupled to a diode array detector (DAD). Total phytochemical compound content was determined by spectrophotometric assays and the antioxidant activity by ferric reducing antioxidant power and β-carotene/linoleic assays. Total phenolic, flavanols, total anthocyanins and yellow flavonoids concentration of tucum-do-cerrado were 122-, 14-, 264- and 61-fold higher in the peel than in the pulp, respectively. The aqueous, methanolic and ethanolic extracts of the tucum-do-cerrado peel exhibited higher antioxidant activity compared to its pulp. Flavanols, anthocyanins, flavones, phenolic acids and stilbenes were the main phenolic classes identified in the tucum-do-cerrado peel extracts. Results suggest that the antioxidant capacity and the phytochemical compound content of the tucum-do-cerrado are mainly associated with the peel. Although flavonoids are the main compounds identified in tucum-do-cerrado peel, other phenolics identified in minor amounts, such as phenolic acids and stilbenes, may be responsible for the high antioxidant capacity of the fruit.  相似文献   
4.
Endogenous polyphenolic compounds in cacao impart both bitter and astringent characteristics to chocolate confections. While an increase in these compounds may be desirable from a health perspective, they are generally incongruent with consumer expectations. Traditionally, chocolate products undergo several processing steps (e.g., fermentation and roasting) that decrease polyphenol content, and thus bitterness. The objective of this study was to estimate group rejection thresholds for increased content of cocoa powder produced from under-fermented cocoa beans in a semisweet chocolate-type confection. The group rejection threshold was equivalent to 80.7% of the non-fat cocoa solids coming from the under-fermented cocoa powder. Contrary to expectations, there were no differences in rejection thresholds when participants were grouped based on their self-reported preference for milk or dark chocolate, indicating that these groups react similarly to an increase in high cocoa flavanol containing cocoa powder.  相似文献   
5.
Selected Greek regional, aged red wines were assessed for their polyphenolic composition using well-established spectrophotometric methodology, and tested for antioxidant potential by three different assays. The total polyphenol (TP) concentration was found to vary from 1217 to 3772 mg L−1 gallic acid equivalents, total anthocyanin (TA) content ranged from 44.3 to 360.1 mg L−1, and total flavanol (TF) from 291.1 to 664.8 mg L−1 catechin equivalents. The antiradical activity was evaluated using DPPH, and varied from 0.73 to 1.37 m Trolox® equivalents, while reducing power values were from 5.29 to 10.80 m ascorbic acid equivalents, using a modified FRAP assay. The hydroxyl free radical scavenging activity was determined with the deoxyribose method, and ranged from 38.5 to 59.9% decrease in A532 relative to control. The examinations showed that TP and TF may provide a significant contribution to the overall antioxidant status of wines, but TA appears to be a less important factor in this respect. Reducing power was found to be highly associated with the antiradical activity of wines.  相似文献   
6.
通过正相硅胶、反相硅胶、大孔吸附树脂、Sephadex LH-20和高效液相色谱等多种现代色谱技术对番荔枝科紫玉盘属植物大花紫玉盘(Uvaria grandiflora)干燥根的化学成分进行系统地分离纯化,得到12个化合物,用现代波谱技术确定化合物的结构分别为:epicatechin-(4β→1′,2→O→2′)-phloroglucinol(1),proanthocyanidin A-1(2),proanthocyanidin A-2(3),表儿茶素(epicatechin)(4),phlorizin(5),圣草酚(eriodictyol)(6),erythro-guaiacylglycerol-8-O-4′-(coniferyl alcohol)ether(7),threo-guaiacylglycerol-8-O-4′-(coniferyl alcohol)ether(8),erythro-guaiacylglycerol-8-O-4′-(sinapyl alcohol)ether(9),threo-syringylglycerol-8-O-4′-(sinapyl alcohol)ether(10),burselignan(11),icariol A2(12)。化合物1~12均为首次从该植物中分离得到,其中化合物1为新天然化合物。  相似文献   
7.
8.
Abstract

There is an increasing interest in dietary polyphenols for risk reduction in cardiovascular diseases. The aim of this study was to evaluate acute and chronic flow-mediated dilation (FMD) and blood pressure responses to daily intake of boysenberry juice. FMD of the brachial artery was measured in six subjects in the initial, intermediate and follow-up stages of a 4-week open-label intervention study. The intake of boysenberry juice (180?ml/d) increased FMD with progression of intervention stage, and FMD differed in the follow-up stage compared with pre-intake baseline (p?=?0.0163?<?0.0167?=?0.1/6) using Bonferroni correction. Changes in systolic blood pressure (SBP) correlated negatively with SBP before intake only in the follow-up stage (r?=??0.961 and p?=?0.0007 at 3.5?h), indicating a greater SBP reduction in subjects with higher SBP. These results suggest that daily intake of boysenberry juice is beneficial for reducing cardiovascular risk.  相似文献   
9.
本文进一步研究了茶黄烷醇类(TF)对血小板聚集以及人血小板丰富血浆产生TXA_2的影响.实验结果表明,TF不但显著地抑制ADP、肾上腺素(Adr),花生四烯酸(AA)诱导的血小板聚集,还明显地抑制了血小板聚集曲线的幅度.高浓度TF对ADP诱导的血小板聚集的抑制程度大于低浓度TF;与阿斯匹林相似,TF不能对已发生聚集的血小板起解聚作用;TF还能明显地抑制人血小板丰富血浆产生血栓素B_2(TXB_2).12名陈旧性心肌梗塞患者经服用粗制的TF2个月后,血小板聚集性及TXB_2水平显著下降.  相似文献   
10.
Teas represent a large family of plants containing high amounts of polyphenols that may confer health benefits in various diseases. Recently, it has been hypothesized that tea consumption may also reduce the risk of age-related neurodegenerative pathologies. Considering the deleterious role of beta-amyloid (Abeta) in the aetiology of Alzheimer's disease (AD), we investigated green and black tea extracts and flavan-3-ols (present as monomers and dimers in green and black forms, respectively) against toxicity induced by Abeta-derived peptides using primary cultures of rat hippocampal cells as model. Both green and black tea extracts (5-25 microg/mL) displayed neuroprotective action against Abeta toxicity. These effects were shared by gallic acid (1-20 microm), epicatechin gallate (ECG; 1-20 microM) and epigallocatechin gallate (EGCG; 1-10 microM), the former being the most potent flavan-3-ol. In contrast, epicatechin and epigallocatechin were ineffective in the same range of concentrations. Moreover, only tea flavan-3-ol gallate esters (i.e. ECG, EGCG) and gallic acid inhibited apoptotic events induced by Abeta(25-35). Interestingly, EGCG and gallic acid inhibited Abeta aggregation and/or the formation of Abeta-derived diffusible neurotoxin ligands. Taken together, these results indicate that the catechin gallates (through the galloyl moiety) contribute to the neuroprotective effects of both green and black teas. Moreover, the protective effect of EGCG is likely to be associated, at least in part, with its inhibitory action on Abeta fibrils/oligomers formation. These data also support the hypothesis that not only green but also black teas may reduce age-related neurodegenerative diseases, such as AD.  相似文献   
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