Aloysia triphylla infusion protects rats against dextran sulfate sodium-induced colonic damage.

BACKGROUND: Inflammatory bowel diseases consist of uncontrolled intestinal inflammation leading to mucosal disruption. Polyphenols are micronutrients with antioxidant and anti-inflammatory properties and may play an interesting role in the prevention of intestinal inflammation. Lemon verbena (Aloysia triphylla (L'Herit.) Britton, Verbenaceae) infusion is a popular herbal drink rich in polyphenols. This study evaluated the protective effects of lemon verbena infusion consumption on the development of dextran sulfate sodium (DSS)-induced colitis in rats. The infusion was given to rats as a drink providing 82 µmol polyphenols day(-1) for 21 days. Colitis was induced with 40 g l(-1) DSS in the drink for the last 7 days. RESULTS: Lemon verbena infusion treatment restored body weight gain and prevented colonic shortening. Despite no protective effect on myeloperoxidase activity, A. triphylla infusion limited histological colonic alterations. CONCLUSION: The results suggest that lemon verbena infusion partially protects rats against DSS-induced inflammation.

Lemon verbena infusion consumption attenuates oxidative stress in dextran sulfate sodium-induced colitis in the rat.

BACKGROUND: Inflammatory bowel diseases (IBD) consist of an uncontrolled intestinal inflammation leading to mucosal disruption. This inflammation is accompanied by an excessive production of reactive oxygen species (ROS). Polyphenols are micronutrients with antioxidative and anti-inflammatory properties, and may play an interesting role in the prevention of intestinal inflammation. Lemon verbena (Aloysia triphylla) infusion is a popular herbal infusion rich in polyphenols (flavones and verbascoside). AIMS: This study evaluated the preventive effects of lemon verbena infusion consumption against mild-to-moderate dextran sulfate sodium (DSS)-induced colitis in rats. METHODS: Wistar rats drank water or lemon verbena infusion for 14 days. On day 15, half of the rats received DSS (4%) in their drink for 7 days. At the end of the experimental period, the colon was taken for histopathological examination and determination of myeloperoxidase (MPO) activity, antioxidant enzyme activities (superoxide dismutase [SOD], glutathione peroxidase [GPx], glutathione reductase [GR], catalase [CAT]), glutathione and lipid peroxidation. Lymphocyte populations were determined in blood, mesenteric nodes and Peyer's patches. RESULTS: Rats ingested daily 5.6 µmol of polyphenols. DSS reduced food intake and induced colitis, as reflected by histological lesions and increased MPO activity. Although these alterations were not significantly counteracted by lemon verbena consumption, the herbal infusion increased colonic SOD activity and decreased lipid peroxidation (malondialdehyde). Other oxidative stress markers (GPx, GR, CAT, glutathione) were not significantly modified. CONCLUSION: Our study shows that the preventive consumption of lemon verbena infusion offered some antioxidative protection during experimental colitis by stimulating SOD activity and decreasing lipid peroxidation.

Variation in content and composition of phenolic compounds in permanent pastures according to botanical variation.

Phenolic compounds contribute to the micronutrient composition of pasture, which in turn may affect animal product composition. To assess the importance and variations in content of these compounds, the polyphenolic and botanical compositions of 24 permanent pastures located in one lowland and two upland regions were studied at equivalent stages of growth. Phenolic fractions were characterized and quantified using HPLC-PDA-ESI-QToF, and the total content was determined by colorimetry over each whole pasture. A rise in altitude was accompanied by a marked increase in total phenolic content, linked to changes in botanical composition, but did not have any influence on the distribution according to molecular class. For all of the pastures, significantly different patterns due to qualitative and quantitative differences among the 92 separate peaks were observed with 31 compounds identified. The involvement of certain plants in the variations of content and composition in phenolic compounds of pastures was statistically evaluated.

Radiolabelled cyanidin 3-O-glucoside is poorly absorbed in the mouse.

Anthocyanins are natural pigments abundant in various fruits and berries that are involved in the prevention of various chronic diseases. Their low concentrations in plasma and urine are explained in part by their complex chemistry and the formation of still uncharacterised metabolites. The aim of the present study was to follow the distribution of anthocyanins in the body using 14C-labelled cyanidin 3-O-glucoside (Cy3G) fed by gavage to mice. After the administration of 22.2 kBq 14C-Cy3G (0.93 mg), radioactivity was detected in most organs tested over the following 24 h with a peak observed in inner tissues at 3 h. The major fraction of the radioactivity (44.5 %) was found in the faeces collected 24 h after ingestion. At 3 h after oral administration of 141 kBq 14C-Cy3G (4.76 mg), most of the radioactivity (87.9 % of intake) was recovered in the gastrointestinal (GI) tract, especially in the small intestine (50.7 %) and the caecum (23 %). At this time, 3.3 % of the radioactivity was detected in urine. There was minimal accumulation (0.76 %) of radioactivity in tissues outside the GI tract. Distribution of radioactivity varied among organs, with liver, gallbladder and kidneys showing the highest radioactivity. Taken as a whole, these results show that Cy3G is poorly absorbed in the mouse.

Tissue distribution of anthocyanins in rats fed a blackberry anthocyanin-enriched diet.

Anthocyanins are natural dietary pigments that could be involved in various health effects. The aim of this study was to investigate the distribution of anthocyanins to various organs (bladder, prostate, testes, heart and adipose tissue) in rats fed with a blackberry anthocyanin-enriched diet for 12 days. Identification and quantification of anthocyanins were carried out by HPLC-DAD. The urinary excretion of total anthocyanins (native anthocyanins and their metabolites) was low (0.20 +/- 0.03%, n = 8). Proportions of anthocyanin derivatives (methylated anthocyanins and glucurono-conjugated derivatives) differed according to the organ considered. The bladder contained the highest levels of anthocyanins followed by the prostate. Prostate, testes and heart contained native cyanidin 3-glucoside and a small proportion of cyanidin monoglucuronide. Cyanidin 3-glucoside and methylated derivatives were present in adipose tissue. Thus, anthocyanin feeding in rats resulted in a wide distribution of anthocyanin derivatives to several organs. Identification of target tissues of anthocyanins may then help to understand the mechanisms of action of anthocyanins in vivo.

Influence of glucose on cyanidin 3-glucoside absorption in rats.

Anthocyanins are natural dietary pigments that could be involved in various health effects. However their mechanisms of absorption are still not fully understood. The aim of this study was to evaluate the influence of glucose on anthocyanin absorption in rats. We first studied anthocyanin bioavailability in rats that received by gastric intubation approximately 53 micromol cyanidin 3-glucoside (Cy 3-glc) equivalents from a red orange extract with or without 2.51 mmol glucose. Neither 24-h urinary anthocyanin excretion nor plasma anthocyanin concentration was significantly affected by simultaneous ingestion of glucose. The influence of glucose (12, 42 or 72 mM) on intestinal absorption of Cy 3-glc (pure or from a red orange extract; approximately 12.3 microM) was further studied using an in situ intestinal perfusion model. Absorption of pure Cy 3-glc from the intestinal lumen was not significantly affected by the amount of glucose. However, intestinal absorption of Cy 3-glc from the red orange extract (6.49 +/- 1.44%, n = 6) was significantly less than that of pure Cy 3-glc (17.5 +/- 1.3%, n = 7) (p < 0.01) suggesting that the red orange extract contained other components that were able to interfere with Cy 3-glc intestinal absorption. This study has thus shown that glucose did not interfere with anthocyanin glucoside absorption.

Strawberry pelargonidin glycosides are excreted in urine as intact glycosides and glucuronidated pelargonidin derivatives in rats.

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.

Absorption and metabolism of red orange juice anthocyanins in rats.

Anthocyanins are natural pigments that could be involved in various health effects. Red oranges are an important dietary source of anthocyanins, including cyanidin 3-glucoside (Cy 3-glc) and an acylated derivative, cyanidin 3-(6''-malonyl)-glucoside (Cy 3-malglc). The aim of this study was to evaluate the absorption and metabolism of red orange anthocyanins in rats fed an anthocyanin-enriched diet for 12 d (approximately 2.8 micromol anthocyanins/d). Furthermore, the absorption of these anthocyanins was studied in both the stomach and intestine using in situ models in rats. Anthocyanin metabolites were identified and quantified by HPLC-electrospray ionization tandem MS and HPLC-diode array detection, respectively. The red orange anthocyanins, Cy 3-glc and Cy 3-malglc, as well as their respective methylated derivatives, were recovered in urine after red orange juice intake. The 24 h urinary excretion of total anthocyanins was low (0.081 (SEM 0.009) % of the ingested amount). However, a high proportion (about 20 %) of red orange anthocyanins was absorbed from the stomach. More Cy 3-malglc than Cy 3-glc was absorbed in the intestine. This study thus indicated that red orange juice anthocyanins were rapidly absorbed from both stomach and small intestine, and then excreted in the urine as intact and methylated forms. Moreover, the absorption and metabolism of acylated anthocyanins and non-acylated anthocyanins were similar.

Blackberry anthocyanins are mainly recovered from urine as methylated and glucuronidated conjugates in humans.

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 mumol 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.

Anthocyanin metabolism in rats and their distribution to digestive area, kidney, and brain.

Anthocyanins are present in human diet due to their wide occurrence in fruits and beverages. They possess antioxidant activities and could be involved in several health effects. The aim of this study was to investigate anthocyanin metabolism and distribution in the digestive area organs (stomach, jejunum and liver) and kidney, as well as a target tissue (brain) in rats fed with a blackberry (Rubus fruticosus L.) anthocyanin-enriched diet for 15 days. Identification and quantification of anthocyanin metabolites was carried out by HPLC-ESI-MS-MS and HPLC-DAD, respectively. The stomach exhibited only native blackberry anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-pentose), while in other organs (jejunum, liver, and kidney) native and methylated anthocyanins as well as conjugated anthocyanidins (cyanidin and peonidin monoglucuronides) were identified. Proportions of anthocyanin derivatives differed according to the organ considered, with the liver presenting the highest proportion of methylated forms. Jejunum and plasma also contained aglycone forms. In the brain, total anthocyanin content (blackberry anthocyanins and peonidin 3-O-glucoside) reached 0.25 +/- 0.05 nmol/g of tissue (n = 6). The urinary excretion of total anthocyanins was low (0.19 +/- 0.02% of the ingested amount). Thus, organs of the digestive area indicated a metabolic pathway of anthocyanins with enzymatic conversions (methylation and/or glucurono-conjugation). Moreover, following consumption of an anthocyanin-rich diet, anthocyanins enter the brain.

Anthocyanins are efficiently absorbed from the small intestine in rats.

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.

Anthocyanins are efficiently absorbed from the stomach in anesthetized rats.

After consumption, anthocyanins are rapidly absorbed as glycosides. Their rapid appearance in plasma could result from absorption through the gastric wall. The aim of this study was to evaluate the fate of anthocyanins in the stomach. Absorption of purified anthocyanins (14 micromol/L) as well as blackberry 14 and 750 micromol/L) and bilberry (88 micromol/L) anthocyanins was compared after in situ gastric administration for 30 min. A high proportion (approximately 25%) of anthocyanin monoglycosides (glucoside or galactoside) was absorbed from the stomach, whereas absorption of cyanidin 3-rutinoside was lower. Bilberry anthocyanins were also efficiently absorbed, but absorption varied greatly (19-37%) according to the anthocyanin structure; delphinidin glycosides were the most absorbed. When a high concentration of blackberry anthocyanins (750 micromol/L) was injected into the gastric lumen, the percentage of cyanidin 3-glucoside (Cy 3-glc) absorption was lower than after administration of a low concentration (14 micromol/L). After administration of this high concentration, blackberry anthocyanins were observed in plasma from gastric vein and aorta, whereas neither aglycones nor metabolites were detected. Analysis of bile samples revealed that Cy 3-glc appeared in bile after as little as 20 min. Peonidin 3-glucoside (the methylated form of Cy 3-glc) as well as unknown anthocyanin metabolites were also observed in bile. Thus, this study demonstrated that anthocyanin glycosides were quickly and efficiently absorbed from the stomach and rapidly excreted into bile as intact and metabolized forms.

Strawberry anthocyanins are recovered in urine as glucuro- and sulfoconjugates in humans.

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 micro mol 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.

Blackberry anthocyanins are slightly bioavailable in rats.

Anthocyanins are phenolic compounds widely distributed in fruits and vegetables. Several positive effects of anthocyanin feeding have been described. We evaluated the absorption and metabolism of anthocyanins (cyanidin 3-glucoside and malvidin 3-glucoside) in rats adapted for 8 d to a diet enriched with a lyophilized blackberry powder. Rats had free access to an anthocyanin-containing diet for 8 h/d. Food was consumed throughout this period, and no anthocyanin accumulated in plasma at any of the times of sampling. Anthocyanins were recovered in urine as the intact glycosidic forms, whereas neither aglycone nor conjugates were detected. Moreover, peonidin 3-glucoside was present in urine and could have resulted from hepatic methylation at the 3' hydroxyl moiety position of cyanidin 3-glucoside. Urinary recovery of cyanidin 3-glucoside in either intact or methylated forms was approximately 0.26% of the ingested amount, whereas that of malvidin 3-glucoside was 0.67%. This result suggested that structure of the aglycone moiety of anthocyanins could play an important role in their metabolism. Low amounts of glucosides as well as of cyanidin were recovered in cecal contents. This could result from adaptation of microflora to anthocyanin degradation. Overall, these data indicate that blackberry anthocyanins are excreted in urine as intact and methylated glucoside forms and that their bioavailability is very low compared with other flavonoids.