Dose and route dependent effects of the mycotoxin deoxynivalenol in a 3D gut-on-a-chip model with flow.

Deoxynivalenol (DON) is the most prevalent mycotoxin in human food and is ubiquitously detected in human bodyfluids. DON leads to intestinal barrier dysfunction, as observed from animal- and cell culture models with the known disadvantages. Here we present the effects of DON in a gut-on-a-chip model, as the first study incorporating the effects of intestinal flow. Using the OrganoPlate 3-lane, Caco-2 cells were seeded against an extracellular matrix (ECM) and formed leak tight tubules. DON was then applied in different concentrations (3 µM to 300 µM) via the apical or the basolateral channel. Permeability was assessed using continuous TEER and barrier integrity assays (BIA). Zonulin-1, toxicity (LDH) and proinflammatory status (IL-8) was analyzed. DON exposure led to a dose dependent decrease in para-and transcellular barrier integrity, which was more sensitive to basal than apical application (route). Timelaps/Continuous TEER measurements however revealed bidirectional effects, with even TEER-inducing effects of lower concentrations (until 10 µM). IL-8 secretion into luminal supernatants was only induced by apical DON. Attributed to the flow, the barrier-disintegrating effects of DON start at higher concentrations than in other culture models. The barrier was more sensitive to basolateral DON, even though DON had to pass the ECM; and IL-8 secretion was independent of TEER-alterations. Thus, the gut-on-a chip model might be a good alternative to further characterize the bidirectional effects of DON with reasonable throughput incorporating flow.

A causal role of estradiol in human reinforcement learning.

The sex hormone estradiol is hypothesized to play a key role in human cognition, and reward processing specifically, via increased dopamine D1-receptor signalling. However, the effect of estradiol on reward processing in men has never been established. To fill this gap, we performed a double-blind placebo-controlled study in which men (N = 100) received either a single dose of estradiol (2 mg) or a placebo. Subjects performed a probabilistic reinforcement learning task where they had to choose between two options with varying reward probabilities to maximize monetary reward. Results showed that estradiol administration increased reward sensitivity compared to placebo. This effect was observed in subjects' choices, how much weight they assigned to their previous choices, and subjective reports about the reward probabilities. Furthermore, effects of estradiol were moderated by reward sensitivity, as measured through the BIS/BAS questionnaire. Using reinforcement learning models, we found that behavioral effects of estradiol were reflected in increased learning rates. These results demonstrate a causal role of estradiol within the framework of reinforcement learning, by enhancing reward sensitivity and learning. Furthermore, they provide preliminary evidence for dopamine-related genetic variants moderating the effect of estradiol on reward processing.

Ingredient-Dependent Extent of Lipid Oxidation in Margarine.

This study reports the impact of margarine-representative ingredients on its oxidative stability and green tea extract as a promising antioxidant in margarine. Oil-in-water emulsions received much attention regarding factors that influence their oxidative stability, however, water-in-oil emulsions have only been scarcely investigated. Margarine, a widely consumed water-in-oil emulsion, consists of 80-90% fat and is thermally treated when used for baking. As different types of margarine contain varying additives, their impact on the oxidative stability of margarine during processing is of pressing importance. Thus, the influence of different ingredients, such as emulsifiers, antioxidants, citric acid, ß-carotene and NaCl on the oxidative stability of margarine, heated at 80 °C for 1 h to accelerate lipid oxidation, was analyzed by the peroxide value and oxidation induction time. We found that monoglycerides influenced lipid oxidation depending on their fatty acyl chain. α-Tocopheryl acetate promoted lipid oxidation, while rosemary and green tea extract led to the opposite. Whereas green tea extract alone showed the most prominent antioxidant effect, combinations of green tea extract with citric acid, ß-carotene or NaCl increased lipid oxidation in margarine. Complementary, NMR data suggested that polyphenols in green tea extracts might decrease lipid mobility at the surface of the water droplets, which might lead to chelating of transition metals at the interface and decreasing lipid oxidation.

Acetone as Indicator of Lipid Oxidation in Stored Margarine.

Margarine contains a minimum of 80% fat and is therefore prone to lipid oxidation. While lipid oxidation in vegetable oils and o/w emulsions has been thoroughly investigated, studies about the oxidative stability and the identification of potential indicators of lipid oxidation in margarine are scarce. To evaluate the oxidative stability and to indicate the progress of lipid oxidation, four different types of industrial margarine (M1-M4), which differed in their composition of the minor ingredients and the oil phase, were stored at 15 °C for 180 days and analyzed at days 0, 1, 7, 14, 28, 56, 99, and 180 regarding peroxides, conjugated dienes, oxidized triacylglycerols, and volatiles. The peroxide value and the conjugated dienes increased up to 4.76 ± 0.92 meq O2/kg oil and 14.7 ± 0.49 in M2, respectively. The oxidative stability decreased by a maximum of 50.9% in M4. We detected three different epoxidized triglycerides-TAG54:1 (O), TAG54:2 (O) and TAG54:3 (O)-in M3. Acetone could be identified, for the first time, as lipid oxidation product in stored margarine by headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). It increased in all types of margarine during storage by a maximum of 1070 ppb in M2. Acetone might be used as a new indicator for lipid oxidation in margarine.

Identification and Quantification of Oxidoselina-1,3,7(11)-Trien-8-One and Cyanidin-3-Glucoside as One of the Major Volatile and Non-Volatile Low-Molecular-Weight Constituents in Pitanga Pulp.

The pulp of pitanga (Eugenia uniflora L.) is used to prepare pitanga juice. However, there are no reports on the identification and quantification of the main constituents in pitanga pulp. The aim of this study was to identify and quantify the major volatile and non-volatile low-molecular-weight constituents of the pulp. Isolation of volatile compounds was performed by solvent-assisted flavor evaporation technique. Characterization of the main volatile and non-volatile constituents was performed by GC-MS, LC-MS and NMR spectroscopy. For quantitative measurements, the main volatile compound needed to be isolated from pitanga pulp to obtain a commercially not available reference standard. Cyanidin-3-glucoside was determined as one of the most abundant non-volatile pulp compound yielding 53.8% of the sum of the intensities of all ions detected by LC-MS. Quantification of cyanidin-3-glucoside in pitanga pulp resulted in a concentration of 344 ± 66.4 µg/mL corresponding to 688 ± 133 µg/g dried pulp and 530 ± 102 µg/g fruit. For the volatile fraction, oxidoselina-1,3,7(11)-trien-8-one was identified as the main volatile pulp constituent (27.7% of the sum of the intensities of all ions detected by GC-MS), reaching a concentration of 89.0 ± 16.9 µg/mL corresponding to 1.34 ± 0.25 µg/g fresh pulp and 1.03 ± 0.19 µg/g fruit. The results provide quantitative evidence for the occurrence of an anthocyanin and an oxygenated sesquiterpene as one of the major volatile and non-volatile low-molecular-weight compounds in pitanga pulp.

Pitanga (Eugenia uniflora L.) fruit juice and two major constituents thereof exhibit anti-inflammatory properties in human gingival and oral gum epithelial cells.

Pitanga, Eugenia uniflora L., is a tropical fruit, which may be consumed as juice. While beneficial health effects of Eugenia uniflora L. leaf extracts have extensively been studied, limited data are available on an anti-inflammatory potential of pitanga juice. The aim of the presented study was to investigate anti-inflammatory properties of pitanga juice with regards to a prevention of inflammation-related periodontal diseases. For this purpose, six healthy volunteers swirled pitanga juice, containing 35% pitanga pulp, for 10 min. Thereafter, oral gum epithelial cells were harvested using a sterile brush and stimulated with lipopolysaccharides from Porphyromonas gingivalis (PG-LPS) for 6 h. Furthermore, human gingival fibroblasts (HGF-1) were used to elucidate the anti-inflammatory potential of pitanga juice constituents, cyanidin-3-glucoside and oxidoselina-1,3,7(11)-trien-8-one, in juice representative concentrations of 119 µg ml(-1) and 30 µg ml(-1), respectively. For the first time, an anti-inflammatory impact of pitanga juice on gingival epithelial cells was shown by means of an attenuation of IL-8 release by 55 ± 8.2% and 52 ± 11% in non-stimulated and PG-LPS-stimulated cells, respectively. In addition, both cyanidin-3-glucoside and oxidoselina-1,3,7(11)-trien-8-one reduced the LPS-stimulated CXCL8 mRNA expression by 50 ± 15% and 37 ± 18% and IL-8 release by 52 ± 9.9% and 45 ± 3.7% in HGF-1 cells, when concomitantly incubated with 10 µg ml(-1)PG-LPS for 6 h, revealing an anti-inflammatory potential of the volatile compound oxidoselina-1,3,7(11)-trien-8-one for the first time.

Identification of Magnolia officinalis L. bark extract as the most potent anti-inflammatory of four plant extracts.

This study was designed to compare the anti-inflammatory potential of a Magnolia officinalis L. bark extract solely or in combination with extracts prepared from either Polygonum aviculare L., Sambucus nigra L., or Isodon japonicus L. in bacterial lipopolysaccharide (LPS) stimulated human gingival fibroblasts (HGF-1) and human U-937 monocytes, as cell models of periodontal disease. HGF-1 and U-937 cells were incubated with LPS from either Porphyromonas gingivalis or Escherichia coli together with the four plant extracts alone or in combination. Secretion of anti-inflammatory cytokines from HGF-1 and U-937 cells was measured by means of a multiplexed bead assay system. Magnolia officinalis L. bark extract, at concentrations of 1 µg/mL and 10 µg/mL, reduced interleukin 6 (IL-6) and interleukin-8 (IL-8) secretion from HGF-1 cells to 72.5 ± 28.6% and reduced matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) secretion from U-937 cells to 8.87 ± 7.97% compared to LPS-treated cells (100%). The other three extracts also reduced secretion of these inflammatory markers but were not as effective. Combination of 9 µg/mL Magnolia officinalis L. extract with 1 µg/mL of each of the other extracts maintained the anti-inflammatory effect of Magnolia officinalis L. extract. Combination of 5 µg/mL Magnolia officinalis L. extract with 5 µg/mL Isodon japonicus L. extract also maintained the anti-inflammatory potential of the Magnolia officinalis L. extract, whereas increasing concentrations of any of the other plant extracts in the combination experiments reduced the Magnolia officinalis L. extract efficacy in U-937 cells.

Identification of 1,8-cineole, borneol, camphor, and thujone as anti-inflammatory compounds in a Salvia officinalis L. infusion using human gingival fibroblasts.

Drinking or gargling Salvia officinalis L. infusion (sage infusion) is thought to soothe a sore throat, tonsillitis, and inflamed, red gums, although structure-based scientific evidence for the key anti-inflammatory compounds in sage infusion is scarce. Human gingival fibroblasts (HGF-1) were treated with sage infusion (SI) or SI fractions containing either its volatile components and water (aqueous distillate, AD) or its dry matter (DM) for six hours. SI, AD, and DM reduced a mean phorbol-12-myristate-13-acetate/ionomycin (PMA/I)-stimulated release of the pro-inflammatory interleukins IL-6 and IL-8 by more than 50% (p < 0.05). Cellular uptake experiments and subsequent GC-MS analysis using stable-isotope-labeled internal standards revealed the presence of 1,8-cineole, borneol, camphor, and α-/ß-thujone in SI-treated cells; LC-MS analysis demonstrated the presence of rosmarinic acid. A significant, more than 50% mean inhibition of PMA/I-induced IL-6 and IL-8 release was demonstrated for the volatile compounds 1,8-cineole, borneol, camphor, and thujone, but not for the nonvolatile rosmarinic acid when applied in concentrations representative of sage infusion. Therefore, the volatile compounds were found to be more effective than rosmarinic acid. 1,8-Cineole, borneol, camphor, and α-/ß-thujone chiefly contribute to the anti-inflammatory activity of sage infusion in human gingival fibroblasts.