scholarly journals Gastrointestinally Digested Protein from the Insect Alphitobius diaperinus Stimulates a Different Intestinal Secretome than Beef or Almond, Producing a Differential Response in Food Intake in Rats

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2366
Author(s):  
Alba Miguéns-Gómez ◽  
Carme Grau-Bové ◽  
Marta Sierra-Cruz ◽  
Rosa Jorba-Martín ◽  
Aleidis Caro ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Food Intake ◽  
Ex Vivo ◽  
Human Colon ◽  
Differential Response ◽  
Alphitobius Diaperinus ◽  
Protein Sources ◽  
Ghrelin Secretion

In this study we compare the interaction of three protein sources—insect, beef, and almond—with the gastrointestinal tract. We measured the enterohormone secretion ex vivo in human and pig intestine treated with in vitro digestions of these foods. Insect and beef were the most effective in inducing the secretion of CCK, while almond was the most effective in inducing PYY in pig duodenum. In the human colon, almond was also the most effective in inducing PYY, and GLP-1 levels were increased by insect and beef. The three digested proteins reduced ghrelin secretion in pig duodenum, while only insect reduced ghrelin secretion in human colon. We also found that food intake in rats increased in groups fed a raw insect pre-load and decreased when fed raw almond. In conclusion, the insect Alphitobius diaperinus modulates duodenal and colonic enterohormone release and increases food intake in rats. These effects differ from beef and almond.

scholarly journals Sensory Stimuli Directly Acting at the Central Nervous System Regulate Gastric Ghrelin Secretion. An ex Vivo Organ Culture Study

Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3998-4006 ◽  
Author(s):  
Luisa M. Seoane ◽  
Omar Al-Massadi ◽  
J. Eduardo Caminos ◽  
Sulay A. Tovar ◽  
Carlos Dieguez ◽  
...  
Keyword(s):  
Organ Culture ◽  
Ex Vivo ◽  
Negative Energy ◽  
Gastrointestinal Hormone ◽  
Suitable Model ◽  
Sensory Stimuli ◽  
Orexigenic Peptide ◽  
The Central Nervous System ◽  
Ghrelin Secretion

Ghrelin, a novel gastrointestinal hormone involved in GH regulation, has been postulated as a relevant orexigenic peptide released by splanchnic tissues. Descriptive studies have shown that plasma ghrelin levels increase in states of negative energy balance or fasting, while decreasing in obesity and after feeding. In the present study, a novel organ-culture model of gastric tissue explants obtained from rat donors has been validated for ex vivo experiments. Fasting induced gastric ghrelin release as well as ghrelin mRNA expression that were reflected in plasma. Interestingly, those changes were fully reverted by 15 min of refeeding before stomach extraction. Unexpectedly, when animals were allowed 15 min before explant extraction to see or smell, but not eat, the food (tease feeding), ghrelin secretion was suppressed just like in gastric explants from refed animals. This effect was blocked when the animals were subjected to surgical vagotomy or treated with atropine sulphate. In conclusion, gastric explants were a suitable model for testing ghrelin mechanism of secretion in vitro, and they were found to maintain memory of the previously received signals. Similar to feeding, tease feeding resulted in suppression of ghrelin discharge by explants.

IN VIVO NEAR-INFRARED FLUORESCENCE IMAGING OF HUMAN COLON ADENOCARCINOMA BY SPECIFIC IMMUNOTARGETING OF A TUMOR-ASSOCIATED MUCIN

2009 ◽  
Vol 02 (04) ◽  
pp. 407-422 ◽  
Author(s):  
RALPH S. DACOSTA ◽  
YING TANG ◽  
TUULA KALLIOMAKI ◽  
RAYMOND M. REILLY ◽  
ROBERT WEERSINK ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Fluorescence Imaging ◽  
Normal Tissue ◽  
Near Infrared ◽  
Ex Vivo ◽  
Colon Adenocarcinoma ◽  
Human Colon ◽  
Human Colon Adenocarcinoma

Background and Aims: Accurate endoscopic detection of premalignant lesions and early cancers in the colon is essential for cure, since prognosis is closely related to lesion size and stage. Although it has great clinical potential, autofluorescence endoscopy has limited tumor-to-normal tissue image contrast for detecting small preneoplastic lesions. We have developed a molecularly specific, near-infrared fluorescent monoclonal antibody (CC49) bioconjugate which targets tumor-associated glycoprotein 72 (TAG72), as a contrast agent to improve fluorescence-based endoscopy of colon cancer. Methods: The fluorescent anti-TAG72 conjugate was evaluated in vitro and in vivo in athymic nude mice bearing human colon adenocarcinoma (LS174T) subcutaneous tumors. Autofluorescence, a fluorescent but irrelevant antibody and the free fluorescent dye served as controls. Fluorescent agents were injected intravenously, and in vivo whole body fluorescence imaging was performed at various time points to determine pharmacokinetics, followed by ex vivo tissue analysis by confocal fluorescence microscopy and histology. Results: Fluorescence microscopy and histology confirmed specific LS174T cell membrane targeting of labeled CC49 in vitro and ex vivo. In vivo fluorescence imaging demonstrated significant tumor-to-normal tissue contrast enhancement with labeled-CC49 at three hours post injection, with maximum contrast after 48 h. Accumulation of tumor fluorescence demonstrated that modification of CC49 antibodies did not alter their specific tumor-localizing properties, and was antibody-dependent since controls did not produce detectable tumor fluorescence. Conclusions: These results show proof-of-principle that our near-infrared fluorescent-antibody probe targeting a tumor-associated mucin detects colonic tumors at the molecular level in real time, and offer a basis for future improvement of image contrast during clinical fluorescence endoscopy.

Influence of Bacillus subtilis C-3102 on microbiota in a dynamic in vitro model of the gastrointestinal tract simulating human conditions

2012 ◽  
Vol 3 (3) ◽  
pp. 229-236 ◽  
Author(s):  
M. Hatanaka ◽  
Y. Nakamura ◽  
A.J.H. Maathuis ◽  
K. Venema ◽  
I. Murota ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Gastrointestinal Tract ◽  
In Vitro Model ◽  
Germination Rate ◽  
Human Colon ◽  
Micro Array ◽  
Vitro Model ◽  
Oral Doses ◽  
The Impact

Survival and germination rate of Bacillus subtilis C-3102 spores were investigated in a stomach and small intestine model (TIM-1), while the impact of C-3102 cells that had passed through TIM-1 on human colon microbiota was evaluated in a model of the large intestine (TIM-2). The survival of C-3102 spores in TIM-1 was 99%; 8% of the spores had germinated. Effluent of TIM-1 was subsequently introduced into TIM-2 and a micro-array platform was employed to assess changes in the microbiota composition. The effluent, which contained germinated C-3102 cells, increased some Bifidobacterium species and decreased some Clostridium groups. These changes were greater compared to those obtained by adding C-3102 spores directly to TIM-2. The present study suggests that oral doses of B. subtilis C-3102 spores have the potential to modulate the human colon microbiota. This effect may be caused by germination of the spores in the gastrointestinal tract.

scholarly journals Pursuing the Mechanisms Underlying Alcohol-Induced Changes in the Ghrelin System: New Insights from Preclinical and Clinical Investigations

2020 ◽  
Author(s):  
Mehdi Farokhnia ◽  
Sara L Deschaine ◽  
Adriana Gregory-Flores ◽  
Lia J Zallar ◽  
Zhi-Bing You ◽  
...  
Keyword(s):  
Gastric Mucosa ◽  
Ex Vivo ◽  
Sucrose Solution ◽  
Ethanol Administration ◽  
Post Mortem ◽  
Wild Type ◽  
Ghrelin Receptor ◽  
Acyl Ghrelin ◽  
Ghrelin Secretion

Ghrelin is a gastric-derived peptide hormone with demonstrated impact on alcohol intake and craving, but the reverse side of this bidirectional link, i.e., the effects of alcohol on the ghrelin system, remains to be fully established. To characterize the downstream effects of alcohol on the ghrelin system, we examined the following: (1) plasma ghrelin levels across four human laboratory alcohol administration experiments with non-treatment seeking, heavy-drinking participants, (2) expression of ghrelin, ghrelin receptor, and ghrelin-O-acyltransferase (GOAT) genes (GHRL, GHSR, and MBOAT4, respectively) in human post-mortem brain tissue from individuals with alcohol use disorder (AUD) vs. controls, (3) plasma ghrelin levels in Ghsr knockout and wild-type rats following intraperitoneal (i.p.) ethanol administration, (4) effect of ethanol on ghrelin secretion from gastric mucosa cells ex vivo and GOAT enzymatic activity in vitro, and (5) plasma ghrelin levels in rats following i.p. ethanol administration vs. an iso-caloric sucrose solution. Peripheral acyl- and total ghrelin levels significantly decreased following acute ethanol administration in humans. No difference in GHRL, GHSR, and MBOAT4 mRNA expression in the brain was observed between AUD vs. control post-mortem samples. In rats, acyl-ghrelin levels significantly decreased following i.p. ethanol administration in both genotype groups (Ghsr knockout and wild-type), while des-acyl-ghrelin was not affected by ethanol. No effect of ethanol was observed ex vivo on ghrelin secretion from gastric mucosa cells or in vitro on GOAT acylation activity. Lastly, we observed different effects of i.p. ethanol and sucrose solution on acyl- and des-acyl-ghrelin in rats despite administering amounts with equivalent caloric value. Ethanol acutely decreases peripheral ghrelin concentrations in humans and rats, and our findings suggest that this effect does not occur through interaction with ghrelin-secreting gastric mucosal cells, the ghrelin receptor, or the GOAT enzyme. Moreover, this effect does not appear to be proportional to caloric load. Our findings, therefore, suggest that ethanol does not suppress circulating ghrelin through direct interaction with the ghrelin system, or in proportion to the caloric value of alcohol, and may differentially affect ghrelin acylation and ghrelin peptide secretion.

scholarly journals Hindbrain GLP-1 receptor-mediated suppression of food intake requires a PI3K-dependent decrease in phosphorylation of membrane-bound Akt

2013 ◽  
Vol 305 (6) ◽  
pp. E751-E759 ◽  
Author(s):  
Laura E. Rupprecht ◽  
Elizabeth G. Mietlicki-Baase ◽  
Derek J. Zimmer ◽  
Lauren E. McGrath ◽  
Diana R. Olivos ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Food Intake ◽  
Intracellular Signaling ◽  
Nucleus Tractus Solitarius ◽  
Ex Vivo ◽  
Mapk Signaling ◽  
Current Data ◽  
Akt Phosphorylation ◽  
Membrane Bound

Glucagon-like peptide-1 (GLP-1) receptors (GLP-1R) expressed in the nucleus tractus solitarius (NTS) are physiologically required for the control of feeding. Recently, NTS GLP-1R-mediated suppression of feeding was shown to occur via a rapid PKA-induced suppression of AMPK and activation of MAPK signaling. Unknown are the additional intracellular signaling pathways that account for the long-term hypophagic effects of GLP-1R activation. Because cAMP/PKA activity can promote PI3K/PIP3-dependent translocation of Akt to the plasma membrane, we hypothesize that hindbrain GLP-1R-mediated control of feeding involves a PI3K-Akt-dependent pathway. Importantly, the novel evidence presented here challenges the dogmatic view that PI3K phosphorylation results in an obligatory activation of Akt and instead supports a growing body of literature showing that activation of cAMP/PKA can inhibit Akt phosphorylation at the plasma membrane. Behavioral data show that inhibition of hindbrain PI3K activity by a fourth icv administration of LY-294002 (3.07 μg) attenuated the food intake- and body weight-suppressive effects of a fourth icv administration of the GLP-1R agonist exendin-4 (0.3 μg) in rats. Hindbrain administration of triciribine (10 μg), an inhibitor of PIP3-dependent translocation of Akt to the cell membrane, also attenuated the intake-suppressive effects of a fourth icv injection of exendin-4. Immunoblot analyses of ex vivo NTS tissue lysates and in vitro GLP-1R-expressing neurons (GT1–7) support the behavioral findings and show that GLP-1R activation decreases phosphorylation of Akt in a time-dependent fashion. Current data reveal the requirement of PI3K activation, PIP3-dependent translocation of Akt to the plasma membrane, and suppression in phosphorylation of membrane-bound Akt to mediate the food intake-suppressive effects of hindbrain GLP-1R activation.

scholarly journals Effects of Flavanols on Enteroendocrine Secretion

Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 844 ◽  
Author(s):  
Carme Grau-Bové ◽  
Carlos González-Quilen ◽  
Ximena Terra ◽  
M. Teresa Blay ◽  
Raul Beltrán-Debón ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Peptide Yy ◽  
Ex Vivo ◽  
Human Colon ◽  
Grape Seed ◽  
Beneficial Effects ◽  
Pure Compounds ◽  
Grape Seed Proanthocyanidin ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Some beneficial effects of grape seed proanthocyanidin extract (GSPE) can be explained by the modulation of enterohormone secretion. As GSPE comprises a combination of different molecules, the pure compounds that cause these effects need to be elucidated. The enterohormones and chemoreceptors present in the gastrointestinal tract differ between species, so if humans are to gain beneficial effects, species closer to humans—and humans themselves—must be used. We demonstrate that 100 mg/L of GSPE stimulates peptide YY (PYY) release, but not glucagon-like peptide 1 (GLP-1) release in the human colon. We used a pig ex vivo system that differentiates between apical and basolateral intestinal sides to analyse how apical stimulation with GSPE and its pure compounds affects the gastrointestinal tract. In pigs, apical GSPE treatment stimulates the basolateral release of PYY in the duodenum and colon and that of GLP-1 in the ascending, but not the descending colon. In the duodenum, luminal stimulation with procyanidin dimer B2 increased PYY secretion, but not CCK secretion, while catechin monomers (catechin/epicatechin) significantly increased CCK release, but not PYY release. The differential effects of GSPE and its pure compounds on enterohormone release at the same intestinal segment suggest that they act through chemosensors located apically and unevenly distributed along the gastrointestinal tract.

The anti-inflammatory potential of a moderately hydrolysed casein and its 5 kDa fraction in in vitro and ex vivo models of the gastrointestinal tract

2015 ◽  
Vol 6 (2) ◽  
pp. 612-621 ◽  
Author(s):  
A. Mukhopadhya ◽  
N. Noronha ◽  
B. Bahar ◽  
M. T. Ryan ◽  
B. A. Murray ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Bioactive Peptides ◽  
Ex Vivo ◽  
Whole Milk ◽  
Wide Range ◽  
Anti Inflammatory ◽  
Physiological Benefits ◽  
Hydrolysed Casein

Bioactive peptides from milk can impart a wide range of physiological benefits without the allergies and intolerance associated with the consumption of whole milk.

Effects of the Tibetan herbal preparation PADMA 28 on blood lipids and lipid oxidisability in subjects with mild hypercholesterolaemia

VASA ◽  
2005 ◽  
Vol 34 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Brunner-La Rocca ◽  
Schindler ◽  
Schlumpf ◽  
Saller ◽  
Suter
Keyword(s):  
Endothelial Dysfunction ◽  
Blood Lipids ◽  
Ex Vivo ◽  
Hdl Cholesterol ◽  
Blood Lipid ◽  
Tibetan Medicine ◽  
Double Blind ◽  
Intraarterial Infusion ◽  
Padma 28

Background: Previous studies showed an anti-atherosclerotic effect of PADMA 28, an herbal formula based on Tibetan medicine. As the mechanisms of action are not fully understood, we investigated whether PADMA 28 may lower blood lipids and lipid oxidisability, and affect early endothelial dysfunction. Patients and methods: Sixty otherwise healthy subjects with total cholesterol ≥5.2 mmol/l and < 8.0 mmol/l were randomly assigned to placebo or PADMA 28, 3 x 2 capsules daily, for 4 weeks (double-blind). Blood lipids (total, LDL-, and HDL-cholesterol, triglycerides, Apo-lipoprotein A1 and B) and ex vivo lipid oxidisability were measured before and after treatment. In a subset of 24 subjects, endothelial function was assessed using venous occlusion plethysmography with intraarterial infusion of acetylcholine. Isolated LDL and plasma both untreated and pre-treated with PADMA 28 extract were oxidised by the radical generator AAPH. Conjugated diene formation was measured at 245 nm. Results: Blood lipids did not change during the study in both groups. In contrast to previous reports in mild hypercholesterolaemia, no endothelial dysfunction was seen and, consequently, was not influenced by therapy. Ex vivo blood lipid oxidisability was significantly reduced with PADMA 28 (area under curve: 5.29 ± 1.62 to 4.99 ± 1.46, p = 0.01), and remained unchanged in the placebo group (5.33 ± 1.88 to 5.18 ± 1.78, p > 0.1). This effect persisted one week after cessation of medication. In vitro experiments confirmed the prevention of lipid peroxidation in the presence of PADMA 28 extracts. Persistent protection was also seen for LDL isolated from PADMA 28-pretreated blood after being subjected to rigorous purification. Conclusions: This study suggests that the inhibition of blood lipid oxidisability by PADMA 28 may play a role in its anti-atherosclerotic effect.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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