Anti-obesity effects of the n-butanol fraction of the methanolic leaf extract of Artemisia campestris from Tunisian pharmacopeia in male Wistar rats.

OBJECTIVES: This study aimed to investigate the effect of the n-butanol fraction of the methanol leaf extract of Artemisia campestris (BFAC), growing wild in the arid zone of Tunisia, on induced obesity in male Wistar rats. METHODS: The total phenolic content and antioxidant capacity of the BFAC were estimated. The main phenolic composition of the BFAC was determined using the high-performance chromatography system coupled with a diode array detector technics. Five groups of rats received either a standard diet (SD group), a high-fat diet (HFD group), or an HFD supplemented with oral administration of BFAC for eight weeks. RESULTS: The BFAC showed higher phenolic content and antioxidant potential than the total leaf methanol extract. Chlorogenic acid, rutin, and dicaffeoylquinic acids were identified in the BFAC. HFD increased body and relative liver weights, as well as serum and hepatic levels of triglycerides and total cholesterol, compared to SD. HFD generated significant oxidative stress in the liver by increasing lipid peroxidation and reducing glutathione-S-transferase, catalase, and glutathione peroxidase activities, compared to SD. These HFD-altered parameters were restored to normal values by oral treatment with the BFAC. CONCLUSIONS: These findings give first evidence about the antiobesity efficacy of A. campestris. Such a study would enhance existing information and promote the use of this species.

Potential Anti-Inflammatory and Chondroprotective Effect of Luzula sylvatica.

(1) Interest in the Juncaceae 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 Luzula sylvatica, a Juncaceae not yet extensively studied, in the context of osteoarthritis. (2) The Luzula sylvatica Ethanol extract (LS-E) was used to test the production of reactive oxygen species (ROS) by leucocytes, the IL1ß 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 IL1ß-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 IL1ß 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) Luzula sylvatica 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.

Impact of Simulated Gastrointestinal Conditions on Antiglycoxidant and α-Glucosidase Inhibition Capacities of Cyanidin-3-O-Glucoside.

Cyanidin-3-O-glucoside (C3G) is a widespread anthocyanin derivative, which has been reported in vitro to exert potent antioxidant, antiglycation and α-glucosidase inhibition effects. Nevertheless, the physiological relevance of such properties remains uncertain considering its significant instability in gastrointestinal conditions. A simulated digestion procedure was thus instigated to assess the influence of gastric and intestinal media on its chemical integrity and biological activities. HPLC analyses of digested C3G samples confirmed the striking impact of intestinal conditions, as attested by a decomposition ratio of 70%. In contrast, with recovery rates of around 90%, antiglycation, as well as DPPH and ABTS scavenging assays, uniformly revealed a noteworthy persistence of its antiglycoxidant capacities. Remarkably, a prominent increase of its α-glucosidase inhibition activity was even observed after the intestinal phase, suggesting that classical in vitro evaluations might underestimate C3G antidiabetic potential. Consequently, the present data provide novel and specific insights on C3G's digestive fate, suggesting that the gastrointestinal tract does not profoundly affect its positive action on oxidative and carbonyl stresses. More specifically, it also tends to support its regulating effects on postprandial hyperglycemia and its potential usefulness for diabetes management.

Stability and Antiglycoxidant Potential of Bilberry Anthocyanins in Simulated Gastrointestinal Tract Model.

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.

Screening and Characterization of Antiglycoxidant Anthocyanins from Vaccinium myrtillus Fruit Using DPPH and Methylglyoxal Pre-Column HPLC Assays.

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.

Anti-Inflammatory and Cytotoxic Potential of New Phenanthrenoids from Luzula Sylvatica.

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.

In Vitro Anti-Inflammatory and Immunomodulatory Activities of an Extract from the Roots of Bupleurum rotundifolium.

BACKGROUND: Some Bupleurum species, such as the Bupleurum chinense DC. or the Bupleurum scorzonerifolium Willd have been extensively studied (especially their roots) for the treatment of inflammation. In contrast, only compounds extracted from the aerial parts of Bupleurum rotundifolium have been studied and showed anti-inflammatory or antiproliferative activities. This study was conducted to investigate the antioxidant, anti-inflammatory, and immunomodulatory effects of Bupleurum rotundifolium roots. METHODS: To tackle the various aspects of inflammation, we studied in vitro a methanolic extract from the roots of Bupleurum rotundifolium on peripheral blood mononuclear cells (PBMCs), polymorphonuclear neutrophils (PMNs), and the monocytic cells THP-1. Its antioxidant capacities and iron-chelating activity were assessed. The extract was tested on THP-1 differentiation, reactive oxygen species (ROS) production by leukocytes, neutrophils chemotaxis, cytokines, PGE2 production, and NF-κB activation in PBMCs. RESULTS: The extract showed a decreased ROS production in stimulated cells. It increased PBMC chemokine secretion and up-regulated the differentiation of THP-1 monocytes into macrophage-like cells, indicating a potential interest of the extract in the resolution of acute inflammation. In addition, the analysis of cytokine production suggests that Bupleurum rotundifolium has immunomodulatory properties. CONCLUSIONS: Cytokines secretion, especially IL-1ß and IL-12p70, provided us with a set of indicators suggesting that the extract might be able to drive the polarization of macrophages and lymphocytes toward a Th2 anti-inflammatory profile in excessive inflammation.

A Novel HPLC Method for Direct Detection of Nitric Oxide Scavengers from Complex Plant Matrices and Its Application to Aloysia triphylla Leaves.

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 Aloysia triphylla 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-O-diglucuronide. These three phenolics were also individually assessed for their NO scavenging activities by using a Griess colorimetric assay. With respective IC50 values of 56 ± 4, 51 ± 3, and 69 ± 5 µg/mL, verbascoside, isoverbascoside, and luteolin-7-O-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.

Antioxidant and antiglycation properties of two mango (Mangifera indica L.) cultivars from Senegal

Objective:To evaluate the total phenolic contents,antioxidant and antigiycation activities of leaves,barks,roots and kernels from two cultiivars of Mangifera indica (Anacardiiaceae).Method:Total phenolic contents were determined by using Folin-Ciocalteu's method.The antioxidant activities were assessed by three different protocols including DPPH,oxygen radical absorbance capacity and iron (Ⅱ) chelation assays.In addition,in vitro bovine serum albumin/D-ribose assay was chosen to evaluate the antiglycation properties of the extracts.Results:All the investigated extracts were found to contain high level of total phenols as well as potent antioxidant activities.Kernel extracts showed the highest total phenol contents and DPPH radical scavenging activities whereas higher oxygen radical absorbance capacity values were observed for leave,root and bark extracts.Besides,extracts from leaves,roots and barks from both cultivars exhibited potent inhibitory effects against the formation of advanced glycation end products,with IC50 values lower than the standard positive control aminoguanidine.Conclusions:The potent antigiycation and antioxidative activities of these two Mangifera indica cultivars suggest a possible role in targeting aging,diabetic complications and oxidative stress related diseases.

Dietary Supplementation with a Low Dose of Polyphenol-Rich Grape Pomace Extract Prevents Dextran Sulfate Sodium-Induced Colitis in Rats.

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.

Polyphenol-rich grape pomace extracts protect against dextran sulfate sodium-induced colitis in rats.

BACKGROUND: Several studies have reported that polyphenols may exert beneficial effects on inflammatory bowel disease. This study aimed to evaluate the effects of preventive consumption of polyphenol-rich red grape pomace extracts (GPEs) on dextran sulfate sodium (DSS)-induced colitis in rats. Rats were fed for 21 days with a semi-synthetic diet enriched with a GPE (Alicante-S, Alicante-P or Pinot-S) and colitis was induced by DSS administration in drinking water (40 g L(-1) ) during the last 7 days of experimentation. RESULTS: GPEs attenuated clinical signs and colon shortening and Alicante GPEs limited histological lesions induced by DSS. GPEs curbed the increase in myeloperoxidase activity and modulated antioxidant enzyme activities. Moreover, GPEs prevented the DSS-induced increase in pro-inflammatory cytokine levels and the up-regulation of various genes implicated in colitis such as intercellular adhesion molecule 1 (ICAM-1) and matrix metalloproteinase 9 (MMP-9). CONCLUSION: These results suggest that polyphenol-rich red GPEs could provide prevention against colon inflammation.

Impact of basal diet on dextran sodium sulphate (DSS)-induced colitis in rats.

PURPOSE: Dextran sodium sulphate (DSS)-induced colitis is a widely used model for inflammatory bowel disease. However, various factors including nutrition may affect the development of this colitis. This study aimed to compare and characterize the impact of purified and non-purified basal diets on the development of DSS-induced colitis in the rat. METHODS: Wistar rats were fed a non-purified or a semi-synthetic purified diet for 21 days. Colitis was then induced in half of the rats by administration of DSS in drinking water (4% w/v) during the last 7 days of experimentation. At the end of the experimental period, colon sections were taken for histopathological examination, determination of various markers of inflammation (myeloperoxidase: MPO, cytokines) and oxidative stress (superoxide dismutase: SOD, catalase: CAT, glutathione peroxidase: GPx and glutathione reductase: GRed activities), and evaluation of the expression of various genes implicated in this disorder. RESULTS: DSS ingestion induced a more marked colitis in animals receiving the purified diet, as reflected by higher histological score and increased MPO activity. A significant decrease in SOD and CAT activities was also observed in rats fed the purified diet. Also, in these animals, administration of DSS induced a significant increase in interleukin (IL)-1α, IL-1ß and IL-6. In addition, various genes implicated in inflammation were over-expressed after ingestion of DSS by rats fed the purified diet. CONCLUSIONS: These results show that a purified diet promotes the onset of a more severe induced colitis than a non-purified one, highlighting the influence of basal diet in colitis development.

Bioavailability of lemon verbena (Aloysia triphylla) polyphenols in rats: impact of colonic inflammation.

Lemon verbena (Aloysia triphylla) infusion, a widely consumed herbal tea, contains significant amounts of polyphenols such as flavone diglucuronides and phenylpropanoid glycosides (mainly verbascoside). We have recently shown that lemon verbena infusion offers beneficial effects against dextran sodium sulphate (DSS)-induced colonic inflammation in rats. The present study aimed to evaluate the bioavailability and intestinal absorption of polyphenols derived from lemon verbena infusion in both healthy and colitic rats. For this purpose, lemon verbena infusion was given to rats ad libitum for 14 d, and then 4 % DSS was added to the infusion for 7 d. Before and after DSS administration, 24 h urinary excretion of polyphenols was determined. Flavones were excreted in the urine as conjugated aglycones, and their excretion was not significantly altered by colonic inflammation. Only trace amounts of verbascoside were excreted in the urine, but various metabolites (hydroxycinnamic acids) were detected. The urinary excretion of hydroxycinnamic acids, particularly that of caffeic acid, increased after DSS administration (P< 0·05). Only flavone aglycones (luteolin and diosmetin) were excreted in the faeces in small proportions (3·2 % of ingested flavones). Intestinal absorption of lemon verbena polyphenols was examined using an in situ intestinal perfusion model. Intestinal absorption of verbascoside and flavone diglucuronides did not significantly differ between the healthy and colitic rats. Collectively, these results show that intestinal absorption and urinary excretion of lemon verbena flavone diglucuronides were not altered by colonic inflammation, but that urinary excretion of hydroxycinnamic acids derived from verbascoside was affected in a colitic situation.

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.

Nutrigenomic analysis of the protective effects of bilberry anthocyanin-rich extract in apo E-deficient mice.

UNLABELLED: Intake of anthocyanin-rich foods has been associated with a reduced risk of cardiovascular diseases. Supplementation with anthocyanin-rich extracts from black rice or purple sweet potato was reported to attenuate atherosclerotic lesion development in apolipoprotein E-deficient (apo E(-/-)) mice. However, the mechanism(s) of their preventive action are not completely understood. Previous studies revealed that anthocyanins altered mRNA levels of genes related to atherosclerosis in cultured macrophages and endothelial cells, but in vivo studies remain scarce. The aim of the study was to investigate the impact of bilberry anthocyanin-rich extract (BE) supplementation on gene expression in the liver of apo E(-/-) mice, the widely used model of atherosclerosis. The liver was chosen because it is the main site of lipid metabolism. Apo E(-/-) mice received for 2 weeks a standard diet supplemented with a nutritional dose of BE (0.02%). This study focused on the early stage of atherosclerosis development for better assessment of anthocyanin action on initiation mechanisms of this pathology. The results showed that a 2-week supplementation significantly reduced plasmatic total cholesterol and hepatic triglyceride levels, whereas the plasmatic antioxidant status remained unchanged. Transcriptional analysis, using microarrays, revealed that the expression of 2,289 genes was significantly altered. BE over-expressed genes involved in bile acid synthesis and cholesterol uptake into the liver and down-regulated the expression of pro-inflammatory genes. These results suggest an anti-atherogenic effect of BE through the regulation of cholesterol metabolism and liver inflammation and provide a global integrated view of the mechanisms involved in the preventive action of this extract. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12263-010-0171-0) contains supplementary material, which is available to authorized users.

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.

Atheroprotective effects of bilberry extracts in apo E-deficient mice.

Previous studies have demonstrated that the intake of berry foods was associated with a reduced risk of cardiovascular diseases. The aim of the present study was to evaluate the effects of two bilberry extracts, one rich in anthocyanins extracted from untreated bilberries (BE) and a second one extracted from yeast-fermented bilberries (FBE), on the development of atherosclerosis in apolipoprotein E-deficient mice (apo E(-/-)). Apo E(-/-) mice received for 16 weeks a diet supplemented with 0.02% of either BE or FBE. Atherosclerotic plaque area was measured in the aortic sinus. Supplementation of the diet with both bilberry extracts led to a significant inhibition of plaque development, whereas no effect on oxidative stress parameters or lipid profiles could be observed, suggesting the implication of other mechanisms of action. In addition, a better protection was observed with FBE, suggesting that the fermentation generates new bioactive compounds more effective in attenuating progression of the atherosclerotic lesions.

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.