Vaccinium myrtillus fruit (bilberry) is well known for its high richness in anthocyanins, which may be responsible for its preventive effects on several oxidative and carbonyl stress-related ...pathologies. However, limited data are available regarding the antioxidant and antiglycative contributions of its constituents. Spectrometric analyses were performed to evaluate anthocyanin content, radical scavenging and antiglycative properties of an anthocyanin-rich extract from bilberries. Additionally, original DPPH and methylglyoxal pre-column HPLC methods were instigated to allow straightforward identification of the main contributors to radical and carbonyl trapping effects. Finally, representative pure anthocyanins were evaluated using classical DPPH and antiglycation assays. Delphinidin, petunidin and cyanidin glycosides were identified as the most effective radical scavenging constituents in both HPLC and spectrometric DPPH evaluations. Potent antiglycative activities were also assessed for cyanidin, delphinidin and petunidin glucosides as attested by their respective IC50 values of 114.2 ± 7.8, 130.5 ± 2.8, and 132.4 ± 3.7 µM. Interestingly, methylglyoxal spiking evaluation demonstrated that all bilberry anthocyanins exerted noticeable and comparable α-dicarbonyl trapping effects. Anthocyanins can be regarded as potent antiglycoxidant agents that might account for some health benefits of bilberries consumption. Besides, significant differences in their contributions were successfully highlighted by the employed pre-column HPLC assays.
The present study aimed at developing an original pre-column HPLC assay allowing rapid characterization of nitric oxide (NO) scavengers from complex plant extracts. Sodium nitroprusside (SNP) was ...employed as a NO donor and spiked with an aqueous extract from
leaves prior to HPLC analysis. Relying on the ability of radical scavenging constituents to be oxidized upon reaction with radicals, this assay successfully allowed direct identification of three potential NO scavengers, including verbascoside, isoverbascoside, and luteolin-7-
-diglucuronide. These three phenolics were also individually assessed for their NO scavenging activities by using a Griess colorimetric assay. With respective IC
values of 56 ± 4, 51 ± 3, and 69 ± 5 µg/mL, verbascoside, isoverbascoside, and luteolin-7-
-diglucuronide were all reported as potent NO scavenging compounds, confirming the efficiency of the SNP spiking HPLC assay. The present method can, thus, be considered as a valuable and effective approach for speeding up the discovery of NO scavenging constituents.
(1) Interest in the
family has risen as some members have shown anti-inflammatory properties and interesting compounds. In this regard, we decided to investigate the antioxidant and anti-inflammatory ...properties of
, a
not yet extensively studied, in the context of osteoarthritis. (2) The
Ethanol extract (LS-E) was used to test the production of reactive oxygen species (ROS) by leucocytes, the IL1β and PGE2 production by peripheral blood mononuclear cells (PBMCs), the production of EP4, and the activation of NFκB in THP-1, as well as the IL1β-activated normal human knee articular chondrocytes (NHAC-Kn) gene expression, grown in monolayers or maintained in alginate beads. (3) Organic acids, caffeoylquinic acids, quercetin and luteolin, compounds frequently found in this family were identified. The LS-E exhibited inhibited ROS formation. The LS-E did not affect NFκB activation and IL1β secretion but dampened the secretion of PGE2 by PBMCs and the presence of EP4 in THP-1. It also modulated the expression of NHAC-Kn in both models and inhibited the expression of several proteases and inflammatory mediators. (4)
might supply interesting antioxidant protection against cartilage damages and lessen joint inflammation, notably by decreasing PGE2 secretion in the synovial fluid. Moreover, it could act directly on chondrocytes by decreasing the expression of proteases and, thus, preventing the degradation of the extracellular matrix.
Anthocyanins are phenolic compounds widely distributed in fruits and vegetables. Their consumption has been shown to prevent some chronic diseases. Anthocyanin metabolism, however, is still not fully ...understood. The aim of this work was to evaluate the bioavailability of anthocyanins in humans consuming a meal containing strawberries and to identify possible metabolites in urine. Six healthy volunteers (three women and three men) consumed a meal containing 200 g strawberries (providing 179 μmol pelargonidin-3-glucoside). Urine samples were collected before and after the meal and rapidly treated by solid-phase extraction. Identification and quantification of anthocyanin metabolites were carried out by HPLC-ESI-MS-MS and HPLC with UV-visible detection, respectively. In addition to pelargonidin-3-glucoside, five anthocyanin metabolites were identified in urine: three monoglucuronides of pelargonidin, one sulfoconjugate of pelargonidin and pelargonidin itself. Total urinary excretion of strawberry anthocyanin metabolites corresponded to 1.80 ± 0.29% (mean ± sem, n = 6) of pelargonidin-3-glucoside ingested. More than 80% of this excretion was related to a monoglucuronide. Four hours after the meal, more than two-thirds of anthocyanin metabolites had been excreted, although urinary excretion of the metabolites continued until the end of the 24-h experiment. This study demonstrated that anthocyanins were glucuro- and sulfo-conjugated in humans and that the main metabolite of strawberry anthocyanins in human urine was a monoglucuronide of pelargonidin.
Anthocyanins are natural pigments that possess antioxidant activities and are implicated in various health effects. Recent studies showed that the stomach is a site of anthocyanin absorption. ...However, the fate of anthocyanins in the small intestine remains unknown. We therefore investigated anthocyanin absorption after in situ perfusion of the jejunum + ileum in rats. The intestine was perfused for 45 min with a physiological buffer supplemented with various anthocyanins. Purified anthocyanin glycosides (9.2 nmol/min) or blackberry (9.0 nmol/min) or bilberry (45.2 nmol/min) anthocyanins were perfused. A high proportion of anthocyanin glycosides was absorbed through the small intestine after perfusion. The rate of absorption was influenced by the chemical structure of the anthocyanin and varied from 10.7 (malvidin 3-glucoside) to 22.4% (cyanidin 3-glucoside). Regardless of the anthocyanins perfused, only glycosides were recovered in the intestinal lumen. After perfusion of a high amount of blackberry anthocyanins (600 nmol/min), native cyanidin 3-glucoside was recovered in urine and plasma from the aorta and mesenteric vein. Methylated and/or glucuronidated derivatives were also identified. Analysis of bile samples revealed that cyanidin 3-glucoside and its methylated derivatives (peonidin 3-glucoside + peonidin glucuronide) quickly appeared in bile. This study demonstrated that anthocyanin glycosides are rapidly and efficiently absorbed from the small intestine. Furthermore, anthocyanins are quickly metabolized and excreted into bile and urine as intact glycosides as well as methylated forms and glucuronidated derivatives.
The consumption of anthocyanins has been shown to prevent certain chronic diseases. However, anthocyanin metabolism has not yet been fully elucidated. The aim of this study was to evaluate ...anthocyanin urinary excretion in humans receiving a meal containing blackberries and to identify possible metabolites in urine. Five healthy volunteers were fed 200 g of blackberries (960 μmol of anthocyanins). Urine samples were collected and rapidly treated by solid-phase extraction. Anthocyanin metabolites were identified and quantified by HPLC-ESI-MS-MS and HPLC with UV−vis detection, respectively. In addition to native cyanidin 3-glucoside, several other anthocyanin metabolites were identified in the urine: methylated glycosides, glucuronides of anthocyanidins and anthocyanins, a sulfoconjugate of cyanidin, and anthocyanidins. Total urinary excretion of blackberry anthocyanin metabolites was 0.160 ± 0.020% (n = 5) of the amount of anthocyanins ingested. Monoglucuronides of anthocyanidins represented >60% of this excretion. Urinary excretion of anthocyanins was maximal between 2 and 4 h after the meal, but continued during the 24 h of the experiment. This study highlighted the influence of aglycon structure on anthocyanin urinary excretion. It demonstrated that anthocyanins are not only methylated but also glucuroconjugated and sulfoconjugated in humans and that the main metabolites of blackberry anthocyanins in human urine were anthocyanidin monoglucuronides. Keywords: Humans; anthocyanins; blackberry; glucuronides; urinary excretion
Anthocyanins from Vaccinium myrtillus fruits have been reported in vitro to exert potent radical scavenging and antiglycation activities. However, the physiological relevance of such properties ...remains unclear given the potential susceptibility of anthocyanin derivatives to digestive conditions. A simulated gastrointestinal tract model was thus implemented to assess the impact of gastric and intestinal phases on the chemical integrity of bilberry anthocyanins and their antiglycoxidant effects. Results demonstrated that the investigated activities as well as total and individual anthocyanin contents were marginally affected by gastric conditions. By contrast, with recoveries ranging from 16.1 to 41.2%, bilberry anthocyanins were shown to be highly sensitive to the intestinal phase. Of major interest, a much better preservation was observed for radical scavenging and antiglycation activities as attested by recovery rates ranging from 79.1 to 86.7%. Consistently with previous observations, the present study confirms the moderate bioaccessibility of anthocyanin constituents. It does however provide valuable information supporting the persistence of substantial radical scavenging and antiglycation activities at each step of the digestion process. Taken together, these data indicate that digestive conditions might not abolish the potential positive effects of bilberry consumption on both oxidative and carbonyl stresses.
Phenanthrenoids have been widely described, in the Juncaceae family, for theirbiological properties such as antitumor, anxiolytic, anti-microbial, spasmolytic, and antiinflammatoryactivities. The ...Juncaceae family is known to contain a large variety ofphenanthrenoids possessing especially anti-inflammatory and cytotoxic properties. Luzulasylvatica, a Juncaceae species, is widely present in the Auvergne region of France, but has neverbeen studied neither for its phytochemical profile nor for its biological properties. We investigatedthe phytochemical profile and evaluated the potential anti-inflammatory activities of L. sylvaticaaerial parts extracts. A bioassay-guided fractionation was carried out to identify the most activefractions. Nine compounds were isolated, one coumarin 1 and eight phenanthrene derivatives (2-9), including four new compounds (4, 5, 8 and 9), from n-hexane and CH2Cl2, fractions. Theirstructures were established by HRESIMS, 1D and 2D NMR experiments. The biological properties,especially the anti-inflammatory/antioxidant activities (ROS production) and antiproliferativeactivity on THP-1, a monocytic leukemia cell line, of each compound, were evaluated. Threephenanthrene derivatives 4, 6, and 7 showed very promising antiproliferative activities.Phenanthrene derivatives.
Evidence from several epidemiological and experimental studies points to a beneficial role of dietary polyphenols in inflammatory bowel disease. In this study, we investigate the protective effect of ...dietary supplementation with various amounts of a polyphenol-rich grape pomace extract (GPE) on the development of dextran sulfate sodium (DSS)-induced colitis in rats. Rats were fed 21 days on a semisynthetic diet enriched with GPE (0.1%, 0.5%, and 1%), and acute colitis was induced by DSS (40 g/L in the drinking water) administration during the last 7 days. The low GPE content in the diet (0.1%) attenuated clinical signs and colon shortening and limited DSS-induced histological lesions. GPE 0.1% also attenuated the DSS-induced increase in myeloperoxidase activity and improved superoxide dismutase activity. Higher amounts of GPE in the diet induced only weak and nonsignificant protective effects. These results suggest that consumption of a low amount of polyphenol-rich GPE helps protect against colitis development.
Anthocyanins are natural dietary pigments with a wide array of biological properties that are possibly involved in the prevention of various diseases. These properties depend on their absorption and ...metabolism in the body. In the present study we first examined the gastric and intestinal absorption of pelargonidin 3-glucoside (Pg 3-glc) using rat in situ models. A high proportion of Pg 3-glc was rapidly absorbed from both the stomach (23 %) and small intestine (24 %). Its metabolism was further studied by feeding rats during 8 d with a diet enriched in freeze-dried strawberries. Only low amounts of total anthocyanins were recovered in 24 h urine (0.163 (SEM 0.013) % of ingested anthocyanins; n 8). Strawberry anthocyanins were analysed in urine by HPLC-electrospray ionisation-tandem MS. Similar proportions of intact glycosides (about 53 %) and glucuronidated metabolites (about 47 %) were found. Pg 3-glc was thus glucuronidated to a larger extent than cyanidin 3-glucoside. These results highlight the influence of the aglycone structure on anthocyanin metabolism.
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