Structural Characterization of Cranberry Arabinoxyloglucan Oligosaccharides.

Cranberry ( Vaccinium macrocarpon) products are widely available in North American food, juice, and dietary supplement markets. The use of cranberry is popular for the prevention of urinary tract infections (UTIs) and other reported health benefits. Preliminary findings by our research group indicate that arabinoxyloglucan oligosaccharides are present in cranberry products and may contribute to the antiadhesion properties of urine produced after cranberry consumption, but relatively little is known regarding the oligosaccharide components of cranberry. This report describes the isolation from two cranberry sources and the complete structure elucidation of two arabinoxyloglucan oligosaccharides through the use of carbohydrate-specific NMR spectroscopic and chemical derivatization methods. These compounds were identified as the heptasaccharide ß-d-glucopyranosyl-(1→4)-[α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranose (1) and the octasaccharide ß-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→4)-[α-l-arabinofuranosyl-(1→2)-α-d-xylopyranosyl-(1→6)]-ß-d-glucopyranose (2). Selected fractions and the isolated compounds were subjected to antimicrobial, cell viability, and E. coli antiadhesion assays. Results indicated that enriched fractions and purified compounds lacked antimicrobial and cytotoxic effects, supporting the potential use of such compounds for disease prevention without the risk for resistance development. Preliminary antiadhesion results indicated that mixtures of oligosaccharides exhibited greater antiadhesion properties than purified fractions or pure compounds. The potential use of cranberry oligosaccharides for the prevention of UTIs warrants continued investigations of this complex compound series.

Consumption of cranberry beverage improved endogenous antioxidant status and protected against bacteria adhesion in healthy humans: a randomized controlled trial.

Consumption of polyphenol-rich foods is associated with lower risk from many chronic diseases. We hypothesized that a single dose of cranberry beverage would improve indices of oxidative stress, inflammation, and urinary antibacterial adhesion activity in healthy humans. Six males and 6 females (18-35 years; body mass index, 19-25 kg/m(2)) consumed placebo, cranberry leaf extract beverage, or low-calorie cranberry juice cocktail (LCJC) once in a randomized, double-blind, placebo-controlled cross-over experimental design trial. The washout period between beverages was 1 week. Blood was collected 0, 2, 4, 8, and 24 hours after beverage consumption for measuring oxidative and inflammatory biomarkers. Urine was collected at 0, 0 to 3, 3 to 6, 6 to 9, 9 to 12, and 24 hours postintervention to assess antibacterial adhesion activity. Consumption of cranberry leaf extract beverage elevated (P < .05) blood glutathione peroxidase activity, whereas LCJC consumption increased (P < .05) glutathione concentrations and superoxide dismutase activity compared with placebo. Cranberry leaf extract beverage and LCJC consumption had no effect on the inflammatory biomarkers measured as compared with placebo. At 0 to 3 hours postconsumption, urine from participants who consumed cranberry beverages had higher (P < .05) ex vivo antiadhesion activity against P-fimbriated Escherichia coli compared with placebo. An acute dose of cranberry beverages improved biomarkers of antioxidant status and inhibition of bacterial adhesion in urine.

Development of a fluorometric microplate antiadhesion assay using uropathogenic Escherichia coli and human uroepithelial cells.

A fluorometric microplate assay has been developed to determine Escherichia (E.) coli adhesion to uroepithelial cells (UEC). P-fimbriated E. coli were labeled with BacLight Green and preincubated 30 min with human urine or standard. Fluorescent-E. coli were added to UEC in mircoplates at a 400:1 ratio, incubated 1 h, and washed, and the fluorescence intensity was measured. Specific labeling and adherence were confirmed by flow cytometry. A myricetin (1) standard curve (0-30 µg/mL) was developed; the lower limit of detection was 0.1 µg/mL, and half-maximal inhibitory concentration was 0.88 µg/mL (intra- and interassay coefficients of variance were <10% and <15%, respectively). Vaccinium macrocarpon (cranberry) extracts, quercetin (2), and procyanidins B1 (3), B2 (4), and C1 (5) showed similar inhibition. Antiadhesion activity of urine samples from subjects (n = 12) consuming placebo or V. macrocarpon beverage determined using this assay was positively correlated (R(2) = 0.78; p < 0.01) with a radiolabeled-E. coli assay.

Development and validation of a sensitive, high-throughput bioassay for the adhesion of radiolabeled E. coli to uroepithelial cells in vitro.

Vaccinium macrocarpon (cranberry) products have been used to prevent uropathogenic Escherichia (E.) coli adherence to uroepithelial cells (UEC) and may help reduce risk of urinary tract infection. Reported herein are the development and validation of an assay to assess antiadhesion activity of V. macrocarpon extracts and human urine. P-fimbriated E. coli (CFT073) was labeled with ³H-uridine, then co-incubated with HTB-4 UEC at a 400:1 ratio. V. macrocarpon extracts (0-17 mg proanthocyanidins/mL) were added to ³H-labeled E. coli before co-incubating with UEC. The assay yielded a sensitive inhibition curve: the lower limit of detection and half-maximal inhibitory concentration were 0.43 and 1.59 mg proanthocyanidins/mL for V. macrocarpon extract CEP 55; intra- and interassay coefficients of variance were <10% and <15%, respectively. V. macrocarpon extract CEP 3283 showed identical adhesion inhibition. Serial dilutions of urine from human participants who consumed V. macrocarpon beverages showed a linear decrease in antiadhesion activity. Antiadhesion assays conducted with urine from a human intervention study also showed good agreement with results obtained using the hemagglutination assay. Therefore, a sensitive, high-throughput, biologically relevant antiadhesion assay using ³H-E. coli co-incubated with UEC is reported, which can be used for studying the action of V. macrocarpon bioactives.

Astaxanthin stimulates cell-mediated and humoral immune responses in cats.

Astaxanthin is a potent antioxidant carotenoid and may play a role in modulating immune response in cats. Blood was taken from female domestic shorthair cats (8-9 mo old; 3.2 ± 0.04 kg body weight) fed 0, 1, 5 or 10mg astaxanthin daily for 12 wk to assess peripheral blood mononuclear cell (PBMC) proliferation response, leukocyte subpopulations, natural killer (NK) cell cytotoxic activity, and plasma IgG and IgM concentration. Cutaneous delayed-type hypersensitivity (DTH) response against concanavalin A and an attenuated polyvalent vaccine was assessed on wk 8 (prior to vaccination) and 12 (post-vaccination). There was a dose-related increase in plasma astaxanthin concentrations, with maximum concentrations observed on wk 12. Dietary astaxanthin enhanced DTH response to both the specific (vaccine) and nonspecific (concanavalin A) antigens. In addition, cats fed astaxanthin had heightened PBMC proliferation and NK cell cytotoxic activity. The population of CD3(+) total T and CD4(+) T helper cells were also higher in astaxanthin-fed cats; however, no treatment difference was found with the CD8(+) T cytotoxic and MHC II(+) activated lymphocyte cell populations. Dietary astaxanthin increased concentrations of plasma IgG and IgM. Therefore, dietary astaxanthin heightened cell-mediated and humoral immune responses in cats.

Dietary astaxanthin enhances immune response in dogs.

No information is available on the possible role of astaxanthin on immune response in domestic canine. Female Beagle dogs (9-10 mo old; 8.2 ± 0.2 kg body weight) were fed 0, 10, 20 or 40 mg astaxanthin daily and blood sampled on wk 0, 6, 12, and 16 for assessing the following: lymphoproliferation, leukocyte subpopulations, natural killer (NK) cell cytotoxicity, and concentrations of blood astaxanthin, IgG, IgM and acute phase proteins. Delayed-type hypersensitivity (DTH) response was assessed on wk 0, 12 and 16. Plasma astaxanthin increased dose-dependently and reached maximum concentrations on wk 6. Dietary astaxanthin enhanced DTH response to vaccine, concanavalin A-induced lymphocyte proliferation (with the 20mg dose at wk 12) and NK cell cytotoxic activity. In addition, dietary astaxanthin increased concentrations of IgG and IgM, and B cell population. Plasma concentrations of C reactive protein were lower in astaxanthin-fed dogs. Therefore, dietary astaxanthin heightened cell-mediated and humoral immune response and reduced DNA damage and inflammation in dogs.

Pigmented potato consumption alters oxidative stress and inflammatory damage in men.

Pigmented potatoes contain high concentrations of antioxidants, including phenolic acids, anthocyanins, and carotenoids. These bioactive compounds have been implicated in the inhibition or prevention of cellular oxidative damage and chronic disease susceptibility. We assessed the effects of pigmented potato consumption on oxidative stress and inflammation biomarkers in adult males. Free-living healthy men (18-40 y; n = 12/group) consumed 150 g of cooked white- (WP), yellow- (YP), or purple-flesh potatoes (PP) once per day for 6 wk in a randomized study. Blood was collected at baseline and wk 6 to analyze total antioxidant capacity (TAC), DNA damage as assessed by plasma 8-hydroxydeoxyguanosine (8-OHdG), protein oxidation, lipid peroxidation, C-reactive protein (CRP), inflammatory cytokines, lymphoproliferation, NK cytotoxicity, and phenotypes. Potatoes were analyzed for TAC, phenolic acids, anthocyanins, and carotenoids. Compared with the WP group, the YP group had higher concentrations of phenolic acids (P < 0.002) and carotenoids (P < 0.001), whereas the PP group had higher concentrations of phenolic acids (P < 0.002) and anthocyanins (P < 0.001). Men who consumed YP and PP tended to have lower (P < 0.08) plasma IL-6 compared with those consuming WP. The PP group tended to have a lower plasma CRP concentration than the WP group (P = 0.07). The 8-OHdG concentration was lower in men who consumed either YP or PP compared with WP. Pigmented potato consumption reduced inflammation and DNA damage in healthy adult males. This offers consumers an improved nutritional choice in potato consumption.

Effect of astaxanthin supplementation on inflammation and cardiac function in BALB/c mice.

Astaxanthin is an antioxidant with immunomodulatory, anti-inflammatory and anticancer properties. This study evaluated the use of dietary astaxanthin to decrease oxidative stress and improve cardiac function, thereby providing a potential cardioprotective supplement. Female BALB/c mice (8 weeks of age) were fed a semi-synthetic diet containing 0, 0.02 or 0.08% astaxanthin for 8 weeks. Cardiac function was assessed by echocardiography bi-weekly, and blood and tissue samples were collected at 8 weeks. Plasma astaxanthin concentrations increased (p<0.05) dose-dependently to 0.5 and 4 mumol/l in the astaxanthin-supplemented mice. Blood glutathione concentrations and lymphocyte mitochondrial membrane potential were not significantly affected by astaxanthin treatment. However, mice fed 0.08% astaxanthin had higher (p<0.05) heart mitochondrial membrane potential and contractility index compared to the control group. These results support the possible use of dietary astaxanthin for cardiac protection.

Effect of dietary astaxanthin at different stages of mammary tumor initiation in BALB/c mice.

The effects of astaxanthin on tumor growth, cardiac function and immune response in mice were studied. Female BALB/c mice were fed a control diet (diet C) for 8 weeks, 0.005% astaxathin for 8 weeks (diet A), or diet C for weeks 1-5 followed by diet A thereafter (diet CA). Mice were injected with a mammary tumor cell line on day 7 and tumor growth was measured daily. Mice fed diet A had extended tumor latency and lower tumor volume (p<0.05). Interestingly, those fed diet CA showed the fastest tumor growth. Astaxanthin feeding elevated plasma astaxanthin concentrations; there was no difference in plasma astaxanthin between mice fed CA and those fed A. Mice fed diet A, but not CA, had a higher (p<0.05) natural killer cell subpopulation and plasma interferon-gamma concentration compared to those fed diet C. Astaxanthin delayed tumor growth and modulated immune response, but only when astaxanthin was given before tumor initiation. This suggests that an adequate blood astaxanthin status is needed to protect against tumor initiation; conversely, astaxanthin supplementation after tumor initiation may be contraindicated.

Astaxanthin uptake in domestic dogs and cats.

BACKGROUND: Research on the uptake and transport of astaxanthin is lacking in most species. We studied the uptake of astaxanthin by plasma, lipoproteins and leukocytes in domestic dogs and cats. METHODS: Mature female Beagle dogs (18 to 19 mo old; 11 to 14 kg BW) were dosed orally with 0, 0.1, 0.5, 2.5, 10 or 40 mg astaxanthin and blood taken at 0, 3, 6, 9, 12, 18 and 24 h post-administration (n = 8/treatment). Similarly, mature domestic short hair cats (12 mo old; 3 to 3.5 kg body weight) were fed a single dose of 0, 0.02, 0.08, 0.4, 2, 5, or 10 mg astaxanthin and blood taken (n = 8/treatment) at the same interval. RESULTS: Both dogs and cats showed similar biokinetic profiles. Maximal astaxanthin concentration in plasma was approximately 0.14 mumol/L in both species, and was observed at 6 h post-dosing. The plasma astaxanthin elimination half-life was 9 to 18 h. Astaxanthin was still detectable by 24 h in both species. In a subsequent study, dogs and cats were fed similar doses of astaxanthin daily for 15 to 16 d and astaxanthin uptake by plasma, lipoproteins, and leukocytes studied. In both species, plasma astaxanthin concentrations generally continued to increase through d 15 or 16 of supplementation. The astaxanthin was mainly associated with high density lipoprotein (HDL). In blood leukocytes, approximately half of the total astaxanthin was found in the mitochondria, with significant amounts also associated with the microsomes and nuclei. CONCLUSION: Dogs and cats absorb astaxanthin from the diet. In the blood, the astaxanthin is mainly associated with HDL, and is taken up by blood leukocytes, where it is distributed to all subcellular organelles. Certain aspects of the biokinetic uptake of astaxanthin in dogs and cats are similar to that in humans.