Water-Soluble Coffee Melanoidins Inhibit Digestive Proteases.

Coffee is one of the most popular beverages around the world and its consumption contributes to the daily intake of dietary melanoidins. Despite the emerging physiological role of food melanoidins, their effect on digestive processes has not been studied so far. In this study, the activity of the gastrointestinal enzymes pepsin and trypsin was investigated in the presence of water-soluble coffee melanoidins. The gastric enzyme pepsin is only slightly affected, whereas the intestinal enzyme trypsin is severely inhibited by coffee melanoidins. The intestinal digestibility of casein was significantly inhibited by coffee melanoidins at a concentration achievable by regular coffee consumption. The inhibition of proteolytic enzymes by coffee melanoidins might decrease the nutritional value of dietary proteins.

The Tibetan Formula Cong zhi 6 in the ORL (ENT) Practice: Experiences with Laryngopharyngeal Reflux.

BACKGROUND: Laryngopharyngeal reflux (LPR) is a frequent condition; in European countries, the prevalence can be estimated as 10-30% of the general population. Treatment includes lifestyle measures and highly dosed proton pump inhibitors (PPIs) over at least 4 weeks. However, PPIs are not unproblematic due to their potential side effects and the known phenomenon of rebound acid hypersecretion. Cong zhi 6 is a multi-herbal Tibetan formula additionally containing calcium carbonate and is available in several European countries as a food supplement Padma Aciben/Padma AciTib. CASE REPORT: Ten patients with LPR took Cong zhi 6. The course of the complaints was documented, and the data were retrospectively analysed. Clinical symptoms as assessed with the Reflux Symptom Index (RSI) questionnaire and the findings in laryngoscopy with the Reflux Finding Score (RFS) both showed marked improvement of several symptoms. The number of patients with pathological LPR sum score was significantly reduced from 8 to 2 patients and from 10 to 1 patient in RSI and RFS, respectively. The mean sum scores were reduced from 18.1 to 8.4 (RSI) and from 12.9 to 4.4 (RFS), respectively. Also, other gastrointestinal symptoms, such as abdominal pain, bloating, feeling of fullness, and nausea, which are usually associated with functional dyspepsia and irritable bowel syndrome, were markedly improved (reduction of mean score of the 3 most frequent symptoms by 77-87%). CONCLUSION: Standard medical treatment for LPR consists in high dosed PPI for at least 4 weeks, which is known for several side effects and does not treat reliable the nonacid component of LPR of pepsin or other gastric enzymes. Therefore, other medical treatment options are urgently needed. The promising data of this case series suggest that the Tibetan herbal formula Cong zhi 6 may be a treatment option in LPR and related gastrointestinal symptoms and warrant further research.Der laryngopharyngeale Reflux (LPR) ist eine häufige Erkrankung. In europäischen Ländern wird die Prävalenz in der Gesamtbevölkerung auf 10­30% geschätzt. Die Behandlung beinhaltet Ernährungs- und Verhaltensänderung sowie die Gabe hochdosierter Protonen-Pumpen-Hemmer (PPI) über mindestens 4 Wochen. PPI sind jedoch aufgrund ihrer hohen potenziellen Nebenwirkungen und des bekannten Rebound-Phänomens der sauren Magensafthypersekretion nicht unproblematisch. Cong zhi 6 ist eine tibetische Rezeptur aus einem Vielpflanzengemisch sowie zusätzlich Calciumcarbonat und ist in einigen europäischen Ländern als Nahrungsergänzungsmittel Padma Aciben/Padma AciTib erhältlich.Zehn Patienten mit laryngo-pharyngealem Reflux (LPR) nahmen Cong zhi 6 ein. Der Beschwerdeverlauf wurde dokumentiert und die Daten retrospektiv analysiert. Die klinischen Symptome, die mithilfe des Reflux Symptom Index (RSI) Fragebogens erfasst wurden und die mittels des Reflux Finding Score (RFS) beurteilten laryngoskopischen Befunde zeigten beide eine deutliche Verbesserung verschiedener Symptome. Die Zahl der Patienten mit pathologischen LPR-Summenscore reduzierte sich signifikant, im RSI von 8 auf 2 und im RFS von 10 auf 1 Patienten. Der mittlere Summenwert sank von 18.1 auf 8.4 (RSI) und von 12.9 auf 4.4 (RFS). Des Weiteren zeigte sich auch bei anderen gastrointestinalen Beschwerden, wie Bauchschmerzen, Blähungen, Völlegefühl und Übelkeit, die normalerweise mit funktioneller Dyspepsie oder Reizdarm zusammenhängen, eine deutliche Verbesserung (durchschnittliche Verringerung des Scores der drei häufigsten Symptome um 77­87%).Die medikamentöse Standardbehandlung bei LPR besteht aus der hochdosierten PPI-Gabe über mindestens 4 Wochen, die jedoch für verschiedene Nebenwirkungen bekannt ist und die nicht-saure Komponente von LPR, wie Pepsin oder andere digestive Enzyme, nicht mitbehandelt. Daher sind andere medikamentöse Behandlungsmöglichkeiten dringend erforderlich. Die vielversprechenden Daten dieser Fallserie deuten darauf hin, dass die tibetische Pflanzenrezeptur Cong zhi 6 eine Behandlungsoption bei LPR sowie deren gastrointestinalen Symptome darstellt und rechtfertigen weitere Studien.

Role of Ca2+ in the pepsin-induced coagulation and in the dynamic in vitro gastric digestion behavior of casein micelles.

The effect of Ca2+ on pepsin-induced hydrolysis of κ-casein and subsequent coagulation of casein micelles was studied in a micellar casein (MC) solution at pH ≈ 6.0 at 37 °C without stirring. An NaCl-supplemented MC solution was used as a positive control to assess the effect of increased ionic strength after CaCl2 addition. Quantitative determination of the released para-κ-casein during the reaction using reverse-phase high-performance liquid chromatography showed that specific hydrolysis of κ-casein by pepsin was little affected by the addition of either CaCl2 or NaCl. However, rheological properties and microstructures of curds induced by pepsin hydrolysis depended markedly on the addition of salts. Addition of CaCl2 up to 17.5 mM facilitated coagulation, with decreases in coagulation time and critical hydrolysis degree, and increases in firming rate and maximum storage modulus (G'max); further addition of CaCl2 (22.5 mM) resulted in a lower G'max. Increased ionic strength to 52.5 mM by adding NaCl retarded the coagulation and resulted in a looser curd structure. In a human gastric simulator, MC, without the addition of CaCl2, did not coagulate until the pH decreased to ≈5.0 after ≈50 min of digestion. Addition of CaCl2 facilitated coagulation of casein micelles and resulted in more cohesive curds with dense structures during digestion, which slowed the emptying rate of caseins. At the same CaCl2 concentration, a sample with higher ionic strength coagulated more slowly. This study provides further understanding on the effect of divalent (Ca2+) ions and ionic strength on the coagulation of casein micelles and the digestion behavior of milk.

Liquid-like Oral Sustained-Release System Based on Acid-Sensitive in situ Hydrogel for Alleviate Gastrointestinal Side Effects of Indobufen.

Commonly, most oral non-steroidal anti-inflammatory drugs (NSAIDs) have known gastric adverse reactions due to their long-term and high dose administration. In this study, a novel liquid sustained-release system based on multiple-unit in situ hydrogel beads was designed to address this issue. The system is composed of sodium alginate (SA), gellan gum (GG), zinc oxide (ZnO), and magnesium oxide (MgO). Furthermore, indobufen was loaded into the system to evaluate its gastric mucosal protection effect. This effect can be attributed to the topical antacid, pepsin inhibition, and sustained drug release properties of the system. It was proven that the stored solid gel system could undergo a "solid to liquid" transition after shaking. Once swallowed, the liquid gel could disperse well in the stomach as hydrogel beads. Then, the "liquid to solid" gelation occurred from the exterior to interior of each multiple-unit gel bead, triggered by the release of Zn2+ and Mg2+ from neutralization reactions. The formed gel demonstrated mild antacid effect that lasted for 3 hours and 66.3% pepsin inhibition in vivo. Moreover, the rats treated with the indobufen gel system showed a drug plasma concentration versus time curve with less fluctuation compared to the rats treated with the marketed preparation (YinDuo®) group. The gel system also exhibited an extended Tmax (6.50 hours) and reduced Cmax (52.87 µg/mL). Additionally, the gastric mucosal protection of the gel system was verified using three types of peptic gastric ulcer models. These findings suggested that this multiple-unit in situ gel could be a potential oral liquid sustained release delivery system for NSAIDs.

A retrospective screening method for carbamate toxicant exposure based on butyrylcholinesterase adducts in human plasma with ultra-high performance liquid chromatography-tandem mass spectrometry.

Carbamate pesticides are extensively used in agriculture for their inhibition to acetylcholinesterase and damages to the insects' neural systems. Because of their toxicity, human poisoning incidents caused by carbamate pesticide exposure have occurred from time to time. What's more, some lethally toxic carbamate toxicants known as carbamate nerve agents (CMNAs) have been supplemented in Schedule 1 of the Annex on Chemicals in the Chemical Weapons Convention (CWC) by Organisation of the Prohibition of Chemical Weapons (OPCW) from 2020. And some other carbamates, like physostigmine, have been used in clinical treatment as anticholinergic drugs and their misuse may also cause damages to the body. Similar to organophosphorus toxicants, carbamate toxicants would react with butyrylcholinesterase (BChE) in plasma when entering the human body, resulting in the BChE adducts, based on which the exposure of carbamate toxicants could be detected retrospectively. In this study, methylcarbamyl nonapeptide and dimethylcarbamyl nonapeptide from pepsin digestion of BChE adducts were identified with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in product ion scan mode. Carbofuran was chosen as the target to establish the detection method of carbamate toxicant exposure based on methylcarbamyl nonapeptide digested from methylcarbamyl BChE. Procainamide-gel affinity purification, pepsin digestion and UHPLC-MS/MS analysis in multiple reaction monitoring (MRM) mode were applied. Under the optimized conditions of sample preparation and UHPLC-MS/MS MRM analysis, the limits of detection (LODs) reached 10.0 ng/mL of plasma exposed to carbofuran with satisfactory specificity. The quantitation approach was established with d3-carbofuran-exposed plasma as the internal standard (IS) and the linearity range was 30.0-1.00 × 103 nmol/L (R2 >0.998) with the accuracy of 95.6%-107% and precision of ≤9% relative standard deviation (RSD). The applicability was also evaluated by N,N-dimethyl-carbamates with the LODs of 30.0 nmol/L for pirimicarb-exposed plasma based on dimethylcarbamyl nonapeptide. Because most of carbamate toxicants has methylcarbamyl or dimethylcarbamyl groups, this approach could be applied on the retrospective screening of carbamate toxicant exposure including CMNAs, carbamate pesticides or carbamate drugs. This study could provide an effective means in the fields of CWC verification, toxicological mechanism investigation and down-selection of potential treatment options.

Ex vivo evaluation of adhesive strength and barrier effect of a novel treatment for esophagitis.

AIM: To investigate the mucoadhesive strength and barrier effect of Esophacare® (Atika Pharma SL, Las Palmas de Gran Canaria) in an ex vivo model of gastro-oesophageal reflux. METHODS: An ex vivo evaluation through the Falling Liquide Film Technique with porcine esophagi was performed, compared to a positive control (Ziverel®; Norgine, Amsterdam), after different washing periods with saline, acidified saline (pH 1.2) and acidified saline with pepsin (2000U/mL). RESULTS: The adhesive mean strength on the oesophageal mucosa of Esophacare was 94.7 (6.0)%, compared to 27.6 (19.1)% of the positive control (p<0.05). These results were homogeneous across the different washes and throughout the tissue. The area covered by 1mL of Esophacare, and its respective persistence after washing was also assessed, yielding a mean global persistence of 74.29 (19.7)% vs. 18.9 (12.3)% for the control (p<0.05). In addition, after 30min exposure to acidified saline with pepsin, Esophacare shows a protective effect on the oesophageal mucosa, detectable histologically: preserved integrity and structure of the apical layers was observed, as well as reduced permeability to the washing solution. CONCLUSIONS: Esophacare shows an adhesive strength close to 100%, irrespective of the washing solution applied or the oesophageal region studied. Histologically, it reduces the abrasive effects of the acidic solution on the oesophageal epithelium, reducing permeability to the washing solution. The results in this ex vivo model of gastro-oesophageal reflux disease (GERD) support its therapeutic potential.

The impact of the soluble protein fraction and kernel hardness on wheat flour starch digestibility.

Wheat is the staple crop for 35% of the world's population, providing a major source of calories, mainly in the form of starch. The digestibility of wheat starch varies between different flours and products. Wheat products that are rapidly digested elicit large post-prandial glucose peaks associated with metabolic disorders. We investigated the impact of protein on starch digestion in three commercial flours with different grain hardness. A soluble extract of wheat proteins reduced starch digestion, even following gastric proteolysis. This extract was enriched in proteinaceous α-amylase inhibitors which were partially degraded during gastric proteolysis. Starch digestion kinetic analysis was carried out for flour samples pre-treated with different pepsin activities. The rate of starch digestion was altered following pepsin pre-digestion, and the extent of starch digestion increased in response to pepsin pre-digestion. We conclude that soluble proteinaceous alpha-amylase inhibitors present in wheat can escape gastric digestion and significantly contribute to reducing starch digestion in the small intestine.

Digestive characteristics of oil body extracted from soybean aqueous extract at different pHs.

Soybean oil bodies (SOBs), a natural source of pre-emulsified oil, have important potential applications in food industry. In this study, SOBs were extracted from raw soybean milk at pH 5.0, 7.0, 8.0, 9.0 and 11.0. The pH 5.0-, 7.0- and 8.0-SOB contained extrinsic proteins (mainly 7S, 11S and γ-conglycinin) and oleosins (24 kDa, 18 kDa and 16 kDa), and pH 9.0-, 11.0-SOB only had oleosins. Extrinsic protein contents decreased from 83.9% at pH 5.0-SOB to 58.2% at pH 8.0-SOB, zeta potentials increased gradually from -21.7 mV to -14.67 mV and particle sizes decreased from 924 nm to 359 nm with increasing extraction pHs. In stomach digestion, oleosins of pH 5.0-, 7.0-, 8.0-SOB were hydrolyzed more rapidly than extrinsic proteins. All 24 kDa oleosins were hydrolyzed during 5 min, and 18 kDa oleosins were completely hydrolyzed at 30 min for all SOBs. Oleosins were hydrolyzed and produced <15 kDa pepsin-resistant peptides. In addition, some 7S and 11S of pH 5.0-, 7.0-, 8.0-SOB resisted pepsin hydrolysis. For all SOB emulsions, zeta potentials decreased and the droplets sizes increased significantly (P < 0.05) with the extension of gastric digestive time. The oil droplets of all SOB emulsions aggregated, and the coalescence of oil droplets more easily occurred in pH 9.0- and 11.0-SOB emulsions. During the intestinal phase, zeta potentials and diameters of the droplets decreased gradually, and the droplets of SOB emulsions dispersed according to the CLSM. FFA release rates of pH 5.0-, 7.0-, 8.0-SOB emulsions increased rapidly and then increased slowly, however, the release tendency of pH 9.0-, 11.0-SOB emulsions were opposite. Total FFA releases of pH 5.0-, 7.0-, 8.0-, 9.0-, 11.0-SOB emulsions were respectively 52.5%, 70.5%, 59%, 48.8%, 43.3% at 180 min. Therefore, the digestive behaviors of SOB emulsions extracted at different pHs were different. This study will provide guidance for SOB products.

Effects of autochthonous strains mixture on gut microbiota and metabolic profile in cobia (Rachycentron canadum).

The fish immune system is a topic or subject that offers a unique understanding of defensive system evolution in vertebrate heredity. While gut microbiota plays several roles in fish: well-being, promoting health and growth, resistance to bacterial invasion, regulation of energy absorption, and lipid metabolism. However, studies on fish gut microbiota face practical challenges due to the large number of fish varieties, fluctuating environmental conditions, and differences in feeding habits. This study was carried out to evaluate the impacts of supplemented three autochthonous strains, Bacillus sp. RCS1, Pantoea agglomerans RCS2, and Bacillus cereus RCS3 mixture diet on cobia fish (Rachycentron canadum). Also, chromatography, mass spectrometry and high throughput sequencing were combined to explore composition and metabolite profile of gut microbiota in juvenile cobia fed with supplemented diet. In the trial group, juvenile cobia received diets supplemented with 1 × 1012 CFU mL-1 autochthonous strains for ten weeks and a control diet without supplementation. Juvenile cobia receiving diets supplementation exhibited significantly improved growth than those without additives (control). Haematological indices, such as red blood cells, white blood cells, corpuscular haemoglobin concentration, mean corpuscular volume, haemoglobin, and mean corpuscular haemoglobin, were higher in the supplemented group. Similarly, digestive enzymes (trypsin, lipase, amylase, pepsin and cellulose, activities) activities were higher in supplemented diet with an indigenous isolates mixture. Serum biochemical parameters albumin, globulin, and total protein were significantly higher, while triglyceride, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and cholesterol showed no significant difference. On the other hand, glucose was significantly (P < 0.05) higher in the group without supplementation. On gene expression in the midgut, Immunoglobulin, Colony-stimulating factor receptor 1, major histocompatibility complex 1 were up-regulated by native isolates while T cell receptor beta, and Major histocompatibility complex 2 showed no significant difference. Gut bacterial composition was altered in fish receiving supplemented diet with autochthonous strains. Metabolomics also revealed that some metabolic pathways were considerably enriched in fish fed with supplemented diet; pathway analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment revealed that differentially expressed metabolites were involved in galactose metabolism, tryptophan metabolism, carbohydrate digestion and absorption, purine metabolism, and ABC transporters. Functional analysis of bacterial community showed that differences in enriched metabolic pathways generally comprised carbohydrate and its metabolites, nucleotide and its metabolites, amino acid and its metabolites, heterocyclic compounds, and tryptamines, cholines, pigments. The current investigation results showed that autochthonous strains mixture has significantly enhanced the growth, survival, and innate and adaptive immunities of juvenile cobia.

RNA-Seq Reveals Protective Mechanisms of Mongolian Medicine Molor-Dabos-4 on Acute Indomethacin-Induced Gastric Ulcers in Rats.

This study aimed to apply transcriptomics to determine how Molor-Dabos-4 (MD-4) protects healthy rats against indomethacin (IND)-induced gastric ulcers and to identify the mechanism behind this protective effect. Rats were pretreated with MD-4 (0.3, 1.5, or 3 g/kg per day) for 21 days before inducing gastric ulcers by oral administration with indomethacin (30 mg/kg). Unulcerated and untreated healthy rats were used as controls. Effects of the treatment were assessed based on the ulcer index, histological and pathological examinations, and indicators of inflammation, which were determined by enzyme-linked immunosorbent assay. Transcriptomic analysis was performed for identifying potential pharmacological mechanisms. Eventually, after identifying potential target genes, the latter were validated by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). After pretreatment with MD-4, gastric ulcers, along with other histopathological features, were reduced. MD-4 significantly (p < 0.05) increased the superoxide dismutase (SOD) levels in ulcers and reduced pepsin, TNF-α, and IL-6 levels. RNA-seq analysis identified a number of target genes on which MD-4 could potentially act. Many of these genes were involved in pathways that were linked to anti-inflammatory and antioxidant responses, and other protective mechanisms for the gastric mucosa. qRT-PCR showed that altered expression of the selected genes, such as Srm, Ryr-1, Eno3, Prkag3, and Eef1a2, was consistent with the transcriptome results. MD-4 exerts protective effects against IND-induced gastric ulcers by reducing inflammatory cytokines and pepsin and increasing the expression of SOD levels. Downregulation of Srm, Ryr-1, Eno3, Prkag3, and Eef1a2 genes involved in regulating arginine and proline metabolism, calcium signaling pathway, HIF-1 signaling pathway, oxytocin signaling pathway, and legionellosis are possibly involved in MD-4-mediated protection against gastric ulcers.

Effect of enzymatic hydrolysis conditions on structure of soy protein isolate/gum arabic complex and stability of oil-in-water emulsion.

BACKGROUND: The emulsifying, antioxidant and foaming properties of soy protein isolate hydrolysates (SPH) can be improved by the addition of gum arabic (GA). We investigated the effects of different hydrolysis conditions on the complexation of SPH and GA, and the effects of the complex on the properties of emulsions. RESULTS: Fluorescence spectroscopy showed that the addition of GA had a stronger effect on bromelain and pepsin hydrolysates than trypsin hydrolysate, and therefore had a higher binding constant (KA ) and a larger number of binding sites (n). The addition of GA could also improve protein solubility and emulsifying ability. The emulsions prepared with complexes, especially the complex of GA and SPH obtained by pepsin hydrolysis for 3 h, had a high absolute charge value, uniform particle size distribution, stable morphology, and good storage stability. After storage, the emulsification index (CI) of the emulsion only increased to 23.08%; its 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity was 24.37 ± 1.22% and its 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS+ ) free radical scavenging activity was largely retained. CONCLUSION: During long-term storage, pepsin-treated protein (especially protein treated for 3 h) and GA can form a stable emulsion with antioxidant properties. This work provides new ideas for the development of natural and safe emulsifiers that have antioxidant properties and can be stored long-term and used in the food industry. © 2022 Society of Chemical Industry.

Evaluation of mechanism(s) of action underlying the antioxidant and antiulcer activity of Sesamum indicum leaves extract in experimental rats.

OBJECTIVE: The current study aimed to estimate phytochemical screening, in vitro antioxidant activity, and gastroprotective activity of Sesamum indicum Linn ethanolic extract. MATERIALS AND METHODS: The current study was held out by ulceration induced by pylorus ligation and indomethacin-induced ulcer screening models in Wister albino rats. The screening of antiulcer activity of ethanolic extract of S. indicum leaves (EESIL) at the different amounts (100, 200, and 400 mg/kg; per orally for 7 days) was compared with omeprazole as a usual antiulcer drug. Additional parameters such as gastric content, pH, total acidity, pepsin activity ulcer score, free acidity, ulcer index (UI), % inhibition of ulcers, mean mucin, pepsin content, and total protein content were observed. RESULTS: In the pylorus ligation model, the pepsin activity free acidity, pepsin content, UI, total acidity, ulcer score, total protein content, and percentage ulcer inhibition were considerably decreased (P < 0.05 and P < 0.01), and mean mucin and gastric content pH extensively elevated (P < 0.05 and P < 0.01) in EESIL tested groups in the comparison of the control group. Doses (100, 200, and 400 mg/kg p.o.) of EESIL showed dose-reliant gastro protective outcomes, a considerable (P < 0.05 and P < 0.01) decrease in gastric parameters as UI and ulcer score and induction in gastric pH and percentage inhibition of ulcer compared with the control group. CONCLUSION: Antioxidant, anti-Ulcer, EESIL, and EESIL show antioxidant activity at different concentration. The fallout of the study indicated that the EESIL had improved antiulcer potential due to the decrease in offensive factors and increase in defensive factors.

Pepsin Diffusivity and In Vitro Gastric Digestion of Soymilk as Affected by Binding of Tea Polyphenols to Soy Proteins.

This study aimed to investigate the effect of tea polyphenol extract (TPE) on the in vitro gastric digestion of soymilk. Fluorescence recovery after photobleaching was applied to measure pepsin diffusivity in soymilk. The characteristics of soymilk digesta were evaluated by gel electrophoresis, degree of hydrolysis (DH), molecular weight distribution, free amino acid analysis, particle size, antioxidant capacity, and trypsin/chymotrypsin inhibitor activity (TIA/CIA). The binding between soy proteins and tea polyphenols could significantly impair in vitro gastric digestion of soymilk by decreasing pepsin diffusivity from 91.3 to 70.3 µm2/s and DH from 17.13 to 13.93% with 1.2 mg/g TPE addition. Soymilk with 0.6 mg/g TPE addition exhibited low TIA/CIA and a strong antioxidant capacity in gastric digesta, which might be good for the following intestinal digestion. A better understanding of the effect of polyphenol on the digestion of protein-based food may be beneficial to innovation in food manufacturing.

Antioxidant Activity Evaluation of Oviductus Ranae Protein Hydrolyzed by Different Proteases.

As nutrition and a health tonic for both medicine and food, the protein content of Oviductus Ranae is more than 40%, making it an ideal source to produce antioxidant peptides. This work evaluated the effects of six different proteases (pepsin, trypsin, papain, flavourzyme, neutral protease and alcalase) on the antioxidant activity of Oviductus Ranae protein, and analyzed the relationship between the hydrolysis time, the degree of hydrolysis (DH) and the antioxidant activity of the enzymatic hydrolysates. The results showed that the antioxidant activity of Oviductus Ranae protein was significantly improved and the optimal hydrolysis time was maintained between 3-4 h under the action of different proteases. Among them, the protein hydrolysate which was hydrolyzed by pepsin for 180 min had the strongest comprehensive antioxidant activity and was most suitable for the production of antioxidant peptides. At this time, the DH, the DPPH radical scavenging activity, the absorbance value of reducing power determination and the hydroxyl radical scavenging activity corresponding to the enzymatic hydrolysate were 13.32 ± 0.24%, 70.63 ± 1.53%, 0.376 ± 0.009 and 31.96 ± 0.78%, respectively. Correlation analysis showed that there was a significant positive correlation between the hydrolysis time, the DH and the antioxidant activity of the enzymatic hydrolysates, further indicating that the hydrolysates of Oviductus Ranae protein had great antioxidant potential. The traditional anti-aging efficacy of Oviductus Ranae is closely related to the scavenging of reactive oxygen species, and its hydrolysates have better antioxidant capacity, which also provides support for further development of its traditional anti-aging efficacy.

Role of Daucus carota in Enhancing Antiulcer Profile of Pantoprazole in Experimental Animals.

The carrot plant (Daucus carota) and its components are traditionally reported for the management of gastric ulcers. This study was performed to evaluate the role of carrot when administered concurrently with a conventional antiulcer treatment, pantoprazole, in alleviating gastric and duodenal ulcers in female experimental animals. The study involved standard animal models to determine the ulcer preventive effect using pylorus ligation, ethanol, and stress induced acute gastric ulcer models and duodenal ulcer models involving cysteamine. Acetic acid-induced chronic gastric ulcer and indomethacin-induced gastric ulcer models were used to evaluate the ulcer healing effect. Carrot fruit (500 mg/kg) and its co-administration with pantoprazole produced significant protection in an ethanol- and stress-induced acute gastric ulcer and cysteamine-induced duodenal ulcer. The healing of the acetic acid-induced chronic gastric ulcer was also augmented with this combination. Both total proteins and mucin contents were significantly increased in indomethacin-induced gastric ulcers. Similarly, in pylorus ligation, the pepsin content of gastric juice, total acidity, and free acidity were reduced. Overall, both ulcer preventive effects and ulcer healing properties of the pantoprazole were significantly enhanced in animals who received the co-administration of carrot fruit (500 mg/kg).

Thermal stable characteristics of acid- and pepsin-soluble collagens from the carapace tissue of Chinese soft-shelled turtle (Pelodiscus sinensis).

The carapace from the Chinese soft-shelled turtle (Pelodiscus sinensis) is used as a traditional Chinese medicine. Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from turtle carapace were isolated and characterized to screen novel collagen material in this study. Yields of 1.0% and 2.8% were obtained for ASC and PSC which contained glycine as the major amino acid and had high imino acid content. Both collagens had maximum ultraviolet absorption peaks of 220 nm. SDS-PAGE revealed that the structure of both collagens was similar, belonging to type I collagen. Relative viscosities of collagens were decreased as the temperature increased. Collagens showed minimum solubility at pH 8 and maximum solubility at a salt concentration of 3%. The denaturation temperature (Td) of PSC was higher whereas the melting temperature was lower than that of ASC. Both ASC and PSC appeared to be spongy like microstructure with fibrillar pores shown by scanning electron microscopy. The results suggest that collagens isolated from turtle carapace has high thermal stability with potential uses as new substitute for mammalian collagen in medicinal, food or biomaterial fields. However, their biological or pharmacological activities are needed to be further studied.

Modulation of gastrointestinal digestion of ß-lactoglobulin and micellar casein following binding by (-)-epigallocatechin-3-gallate (EGCG) and green tea flavanols.

The effect of binding of flavonoids, (-)-epigallocatechin-3-gallate (EGCG) and green tea extract (GTE), to beta-lactoglobulin (ß-Lg) and micellar casein (micellar casein isolate, MCI) on protein digestibility was investigated. ß-Lg resisted digestion by pepsin, but in the presence of EGCG the digestion of ß-Lg was enhanced. Binding of EGCG to ß-Lg was identified by nitro blue tetrazolium (NBT) staining and found, by isothermal titration calorimetry, to be an enthalpy-driven exothermic process, with a binding constant of 19 950 L mol-1. Binding promoted a more rapid digestion of ß-Lg during simulated upper duodenal digestion. NBT staining indicated a loss of binding of EGCG to ß-Lg during combined gastric and distal small intestinal digestion and correlated with the cleavage of ß-Lg. However, increased ß-Lg heteromer formation and reduced ß-Lg monomer digestibility were observed for the ß-Lg-GTE complex. MCI was more digestible than ß-Lg during pepsin digestion, but reduced digestibility was observed for both MCI-EGCG and MCI-GTE complexes, with loss of binding during intestinal digestion. The free radical scavenging capacity (FRSC) of EGCG remained stable for the ß-Lg-EGCG complex throughout the gastric and intestinal phases of digestion, but this was significantly lowered for the MCI-EGCG complex. These results indicated that polyphenols bind to milk proteins modulating the in vitro digestibility and FRSC of ß-Lg and MCI as a result of the formation of complexes.

Effect and mechanism of ethanol extracts of muxiang (Radix Aucklandiae) on gastric ulcers in rats.

OBJECTIVE: To investigate the effect of ethanol extracts of Muxiang (Radix Aucklandiae) (RA) on gastric ulcers in rats and explore the potential mechanisms. METHODS: A model was established by ethanol (0.75 mL/kg). According to body weight, rats were pretreated with RA extracts (2.5 or 5 g/kg). The rats were administered 95% ethanol orally after 1 h. The effects of ethanol were evaluated by measuring the gastric secretion volume, pH, pepsin activity, and ulcer area. Histological analysis and immunohistochemistry were also conducted. Furthermore, the effect of the ethanol extract of RA on transiting activity of the gastrointestinal tract was observed in mice. RESULTS: Intragastric administration of RA extracts protected the gastric mucosa from ethanol-induced gastric ulcers, while reducing submucosal edema and preventing hemorrhagic damage. Moreover, the extracts increased the production of gastric mucus, upregulated Bcl-2, and downregulated Bax expression. Importantly, pretreated rats exhibited no significant change in the gastric secretion volume, gastric juice acidity, or pepsin. Furthermore, pretreatment prominently (P < 0.05) enhanced propulsive movement of the gastrointestinal tract in normal mice and mice with gastrointestinal motility disorders. CONCLUSION: Ethanol extracts of RA ameliorated gastric lesions in the gastric ulcer rat model. The mechanisms of action were related to improvement of gastrointestinal dynamics, maintenance of mucus integrity, and inhibition of apoptosis by downregulating proapoptotic Bax protein and upregulating anti-apoptotic Bcl-2 protein.

Effects of dietary exogenous xylanase supplementation on growth performance, intestinal health, and carbohydrate metabolism of juvenile large yellow croaker, Larimichthys crocea.

An 8-week feeding trial was conducted to evaluate the effects of dietary xylanase supplementation on growth performance, digestive enzyme activity, intestinal morphology parameter, intestinal microbiome diversity, and carbohydrate metabolism for juvenile large yellow croaker (Larimichthys crocea). Four levels of xylanase were added to basal diets (0, 600, 1200, and 1800 U kg-1). The results indicated that fish fed the 1200 U kg-1 xylanase diet had higher weight gain than those fed the 0 and 600 U kg-1 xylanase diet. The highest intestinal folds and microvillous height were observed at fish fed the 1200 U kg-1 xylanase diet. High-throughput sequencing revealed that the majority of reads derived from the large yellow croaker digesta belonged to members of Proteobacteria followed by Chloroflex, Bacteroidetes, Spirochaetae, and Firmicute. Supplementation of xylanase in diets increased the relative abundance of Bacteroides and Gemmatimonadete. The higher hepatic glucokinase (GK) and glucose-6-phosphate dehydrogenase (G6PD) activities were observed in fish fed the xylanase supplementation diet. Accordingly, dietary xylanase supplementation upgraded the relative expressions of gk and g6pd genes in liver. In conclusion, optimum dietary xylanase supplementation (600-1200 U kg-1) could improve the growth performance, optimize the intestinal morphology structure and microbiota constitution, and enhance the ability of carbohydrate utilization of juvenile large yellow croaker.

Contribution of soybean polysaccharides in digestion of oil-in-water emulsion-based delivery system in an in vitro gastric environment.

This study aims to evaluate the effects of soy soluble polysaccharide and soy hull polysaccharide on stability and characteristics of emulsions stabilised by soy protein isolate in an in vitro gastric environment. Zeta potential and particle size were used to investigate the changes of physico-chemical and stability in the three emulsions during in vitro gastric digestion, following the order: soy protein isolate-stability emulsion < soy protein isolate-soy soluble polysaccharide -stability emulsion < soy protein isolate-soy hull polysaccharide-stability emulsion, confirming that coalescence in the soy protein isolate-stability emulsion occurred during in vitro gastric digestion. Optical microscopy and stability measurement (backscattering) also validate that addition of polysaccharide (soy soluble polysaccharide and soy hull polysaccharide) can reduce the effect of simulated gastric fluid (i.e., pH, ionic strength and pepsin) on emulsion stability, especially, soy protein isolate-soy hull polysaccharide-stability emulsion, compared with soy protein isolate-stability emulsion. This suggests that the flocculation behaviours of these emulsions in the stomach lead to a difference in the quantity of oil and the size and structure of the oil droplets, which play a significant role in emulsion digestion in the gastrointestinal tract. This work may indicate a potential application of soy hull polysaccharide for the construction of emulsion food delivery systems.