Static and dynamic in vitro digestion models to study protein stability in the gastrointestinal tract

2015 ◽  
Vol 17-18 ◽  
pp. 23-27 ◽  
Author(s):  
Didier Dupont ◽  
Alan R. Mackie
Keyword(s):  
Gastrointestinal Tract ◽  
Protein Stability ◽  
In Vitro Digestion

scholarly journals Stability of Anthocyanins from Commercial Black Currant Juice under Simulated Gastrointestinal Digestion

2008 ◽  
Vol 8 (3) ◽  
pp. 254-258 ◽  
Author(s):  
Alija Uzunović ◽  
Edina Vranić
Keyword(s):  
Gastrointestinal Tract ◽  
Biological Activities ◽  
In Vitro Digestion ◽  
The Body ◽  
Slight Reduction ◽  
Intestinal Fluid ◽  
Black Currant ◽  
Age Related ◽  
The Stability

Anthocyanins are effective antioxidants but they have also been proposed to have other biological activities independent of their antioxidant capacities that produce health benefits. Examples range from inhibition of cancer cell growth in vitro, induction of insulin production in isolated pancreatic cells, reduction of starch digestion through inhibition of a-glucosidase activity, suppression of inflammatory responses as well as protection against age-related declines in cognitive behavior and neuronal dysfunction in the central nervous system. However, to achieve any biological effect in a specific tissue or organ, anthocyanins must be bioavailable; i.e. effectively absorbed from the gastrointestinal tract (GIT) into the circulation and delivered to the appropriate location within the body. In this study, we assess the stability of anthocyanins from commercial Black currant (Ribes nigrum L.) juice using an in vitro digestion procedure that mimics the physiochemical and biochemical conditions encountered in the gastrointestinal tract (GIT). The main objective of this work was the evaluation of stability of anthocyanins during in vitro digestion in gastric and intestinal fluid regarding whether appropriate enzyme (pepsin or pancreatin) was added or not. Anthocyanins present in commercial black currant juice remain stable during in vitro digestion in gastric fluid regardless whether pepsin was added into the medium or not. Also, they remain stable during in vitro digestion in simulated intestinal fluid without pancreatin. The stability studies of anthocyanins in the intestinal fluid containing pancreatin indicated reduced stability, which also mainly contribute to slight reduction of total anthocyanins content (1,83%-) in commercial black currant juice.

scholarly journals A Comparative Study of the Physical Changes of Two Soluble Fibers during In Vitro Digestion

Proceedings ◽  
2020 ◽  
Vol 53 (1) ◽  
pp. 21
Author(s):  
Natalia Vera ◽  
Laura Laguna ◽  
Liliana Zura ◽  
Loreto A. Muñoz
Keyword(s):  
Particle Size ◽  
Gastrointestinal Tract ◽  
Xanthan Gum ◽  
Dilution Effect ◽  
In Vitro Digestion ◽  
General Terms ◽  
Chia Mucilage ◽  
Physical Changes ◽  
Degree Of Fragmentation

This research aimed to compare the apparent viscosity and the degree of fragmentation/aggregation produced in dispersions of xanthan gum and chia mucilage during the gastrointestinal tract by using an in vitro digestion. Both soluble fibers exhibited pseudoplastic behavior, independent of the concentration and stage of digestion (oral, gastric or intestinal). The viscosity decreased from the oral to intestinal stage in all the concentrations, produced mainly by the “dilution effect” by the addition of digestive fluids. The particle size of xanthan gum increased drastically in the gastric stage mainly due to the decrease in pH, but at intestinal level returned to its original pattern, while particle size and pattern of mucilage during all the stages of digestion remained unchanged, maintaining its integrity. In general terms, since chia mucilage and xanthan gum maintain their viscosity and integrity through the gastrointestinal tract, they could be used as functional ingredients improving the functionality of foods.

scholarly journals Mycotoxin Interactions along the Gastrointestinal Tract: In Vitro Semi-Dynamic Digestion and Static Colonic Fermentation of a Contaminated Meal

Toxins ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 28
Author(s):  
Maria Madalena Costa Sobral ◽  
Tiago Gonçalves ◽  
Zita E. Martins ◽  
Christine Bäuerl ◽  
Erika Cortés-Macías ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Growth Parameters ◽  
In Vitro Digestion ◽  
Oral Route ◽  
Intestinal Cell ◽  
No Production ◽  
Colonic Fermentation ◽  
Reduced Toxicity ◽  
The Impact

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) naturally co-occur in several foods, but no studies have followed the fate of mycotoxins’ interactions along the gastrointestinal tract using in vitro digestion models. This study used a novel semi-dynamic model that mimics gradual acidification and gastric emptying, coupled with a static colonic fermentation phase, in order to monitor mycotoxins’ bioaccessibility by the oral route. AFB1 and OTA bioaccessibility patterns differed in single or co-exposed scenarios. When co-exposed (MIX meal), AFB1 bioaccessibility at the intestinal level increased by ~16%, while OTA bioaccessibility decreased by ~20%. Additionally, a significant increase was observed in both intestinal cell viability and NO production. With regard to mycotoxin–probiotic interactions, the MIX meal showed a null effect on Lactobacillus and Bifidobacterium strain growth, while isolated AFB1 reduced bacterial growth parameters. These results were confirmed at phylum and family levels using a gut microbiota approach. After colonic fermentation, the fecal supernatant did not trigger the NF-kB activation pathway, indicating reduced toxicity of mycotoxins. In conclusion, if single exposed, AFB1 will have a significant impact on intestinal viability and probiotic growth, while OTA will mostly trigger NO production; in a co-exposure situation, both intestinal viability and inflammation will be affected, but the impact on probiotic growth will be neglected.

scholarly journals Evolution of in vitro digestibility techniques: a systematic review

2022 ◽  
Vol 6 (4) ◽  
pp. 300-310
Author(s):  
I. M. Chernukha ◽  
A. V. Meliashchenia ◽  
I. V. Kaltovich ◽  
E. R. Vasilevskaya ◽  
M. A. Aryzina ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
In Vitro Digestion ◽  
Enzymatic Digestion ◽  
Model Systems ◽  
In Vitro Digestibility ◽  
Physiological Processes ◽  
Kjeldahl Method ◽  
Ph Stat

The inability to reproduce certain digestive processes in vivo, high research costs and ethical aspects have led to the development of a large number of in vitro digestion models. These models allow us to take into account various factors of modeling complex multistage physiological processes occurring in the gastrointestinal tract, which makes them promising and widely used. A significant part of in vitro methods includes assessment by enzymatic digestion and are based on the calculation of nitrogen remaining after digestion in relation to the initial total nitrogen (according to the Dumas, Kjeldahl method, spectrophotometric or chromatographic method). There are also a number of titrometric methods (pH‑stat), which are mainly used to assess the digestibility of feed, most successfully for aquatic animals due to the simplicity of their digestive tract. Methods for assessing the digestibility of food products by enzymatic digestion have undergone various stages of evolution (since 1947) and have been widely modified by including various enzymes (pepsin, trypsin, pancreatin, erepsin, etc.) in model systems, indices for various products have been determined on their basis (pepsin-digest-residue (PDR) index, 1956; pepsin pancreatin digest (PPD) index, 1964; pepsin digest dialysate (PDD), 1989). As a result, a single protocol was formed to study the digestibility of food — INFOGEST (2014–2019), which includes three stages of digestion (oral, gastric and intestinal). It allows researchers to accurately reproduce the conditions of the human gastrointestinal tract and is widely used by scientists around the world.

Applicability of Instability Index for In vitro Protein Stability Prediction

2019 ◽  
Vol 26 (5) ◽  
pp. 339-347 ◽  
Author(s):  
Dilani G. Gamage ◽  
Ajith Gunaratne ◽  
Gopal R. Periyannan ◽  
Timothy G. Russell
Keyword(s):  
Protein Stability ◽  
Caulobacter Crescentus ◽  
Effect Of Temperature ◽  
Instability Index ◽  
Dipeptide Composition ◽  
Experimental Conditions ◽  
The Stability ◽  
Vitro Protein

Background: The dipeptide composition-based Instability Index (II) is one of the protein primary structure-dependent methods available for in vivo protein stability predictions. As per this method, proteins with II value below 40 are stable proteins. Intracellular protein stability principles guided the original development of the II method. However, the use of the II method for in vitro protein stability predictions raises questions about the validity of applying the II method under experimental conditions that are different from the in vivo setting. Objective: The aim of this study is to experimentally test the validity of the use of II as an in vitro protein stability predictor. Methods: A representative protein CCM (CCM - Caulobacter crescentus metalloprotein) that rapidly degrades under in vitro conditions was used to probe the dipeptide sequence-dependent degradation properties of CCM by generating CCM mutants to represent stable and unstable II values. A comparative degradation analysis was carried out under in vitro conditions using wildtype CCM, CCM mutants and two other candidate proteins: metallo-β-lactamase L1 and α -S1- casein representing stable, borderline stable/unstable, and unstable proteins as per the II predictions. The effect of temperature and a protein stabilizing agent on CCM degradation was also tested. Results: Data support the dipeptide composition-dependent protein stability/instability in wt-CCM and mutants as predicted by the II method under in vitro conditions. However, the II failed to accurately represent the stability of other tested proteins. Data indicate the influence of protein environmental factors on the autoproteolysis of proteins. Conclusion: Broader application of the II method for the prediction of protein stability under in vitro conditions is questionable as the stability of the protein may be dependent not only on the intrinsic nature of the protein but also on the conditions of the protein milieu.

Rare Germline GLMN Variants Identified from Blue Rubber Bleb Nevus Syndrome Might Impact mTOR Signaling

2020 ◽  
Vol 22 (10) ◽  
pp. 675-682 ◽  
Author(s):  
Jie Yin ◽  
Zhongping Qin ◽  
Kai Wu ◽  
Yufei Zhu ◽  
Landian Hu ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Sanger Sequencing ◽  
Somatic Mutations ◽  
Venous Malformation ◽  
Underlying Disease ◽  
Mtor Signaling ◽  
Functional Effect ◽  
Germline Variants ◽  
Whole Exome

Backgrounds and Objective: Blue rubber bleb nevus syndrome (BRBN) or Bean syndrome is a rare Venous Malformation (VM)-associated disorder, which mostly affects the skin and gastrointestinal tract in early childhood. Somatic mutations in TEK have been identified from BRBN patients; however, the etiology of TEK mutation-negative patients of BRBN need further investigation. Method: Two unrelated sporadic BRBNs and one sporadic VM were firstly screened for any rare nonsilent mutation in TEK by Sanger sequencing and subsequently applied to whole-exome sequencing to identify underlying disease causative variants. Overexpression assay and immunoblotting were used to evaluate the functional effect of the candidate disease causative variants. Results: In the VM case, we identified the known causative somatic mutation in the TEK gene c.2740C>T (p.Leu914Phe). In the BRBN patients, we identified two rare germline variants in GLMN gene c.761C>G (p.Pro254Arg) and c.1630G>T(p.Glu544*). The GLMN-P254R-expressing and GLMN-E544X-expressing HUVECs exhibited increased phosphorylation of mTOR-Ser-2448 in comparison with GLMN-WTexpressing HUVECs in vitro. Conclusion: Our results demonstrated that rare germline variants in GLMN might contribute to the pathogenesis of BRBN. Moreover, abnormal mTOR signaling might be the pathogenesis mechanism underlying the dysfunction of GLMN protein.

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