Pancreatin Digestion Research Articles

A novel angiotensin I-converting enzyme inhibitory peptide APPLRP from Grifola frondosa ameliorated the Ang II-induced vascular modeling in zebrafish model by mediating smooth muscle cells

Grifola frondosa has garnered significant popularity as an edible mushroom attributable to its exceptional taste and nutritional benefits. This study isolated APPLRP, a potent ACE-inhibitory peptide, from the alcohol-soluble fraction of Grifola frondosa. The underlying mechanisms of APPLRP in antihypertension were explored through computational chemistry, cell experiments, and zebrafish model. Results demonstrated that APPLRP was an active competitive ACE inhibitor (IC50 = 29.93 μM) that could bind to the active pocket S2 and S1′ of ACE. APPLRP exhibited resistance to pepsin and pancreatin digestion. In vitro experiments revealed that APPLRP significantly attenuated Ang II-induced VSMCs proliferation and migration by down-regulating AT1R expression and inhibiting ERK1/2 and STAT3 phosphorylation. APPLRP intervention significantly ameliorated myocardial fibrosis, as evidenced by reductions in cardiac output, blood flow velocity, and cardiac collagen deposition levels in Ang II-induced hypertensive zebrafish model. Furthermore, APPLRP improved vascular remodeling in hypertensive zebrafish, indicated by increased vessel diameter and decreased vessel wall thickness. Notably, APPLRP treatment resulted in down-regulation of ACE and up-regulation of ACE2 expression in the vessels of hypertensive zebrafish. These findings indicated that APPLRP was a representative component of Grifola frondosa peptides, and its antihypertensive effects were associated with ACE inhibition and the improvement of VSMCs-mediated vascular remodeling.

Attenuated-total-reflection Fourier-transformed spectroscopy as a rapid tool to reveal the molecular structure of insect powders as ingredients for animal feeds

Abstract Unsustainable agriculture contributes to disastrous global effects – insect-based feed shows potential due to their sustainable, nutritional, and waste upcycling properties. Current EU legislation restricts insect-based meals to fish, pork, and poultry feed; but the near-future shows a great potential for wider acceptance in livestock feed. Black soldier fly larvae (BSFL), mealworm (MW), field cricket (FC), and banded cricket (BC) were sourced within three consecutive weeks – each batch was prepared, freeze-dried, then milled, and stored at −20 °C. Chemical composition of whole-insect meals was analysed for ether extract (EE), crude ash, and nitrogenic contents using standard wet chemistry protocols. Monogastric in vitro digestibility was determined through replicating gastric and full intestinal digestion; during this, R-amino acid content was determined through protein hydrolysis kinetics. Additionally, ATR-FTIR was used for molecular analysis, including identification of nutrient-associated functional spectral bands – structural differences were compared through principal component analysis. Insect-based ATR-FTIR analysis demonstrates notable differences in Amide regions, suggesting distinct protein secondary structures, but overall, FC and BC contain the highest crude protein (CP) levels. The lowest CP content was in BSFL; however, BSFL contained the highest ash content – likely consequence of high calcium. Dry matter (DM) yielded lowest in the crickets (FC-28.6; BC-26.9 g/100 g), and highest in MW-38.5 g/100 g; the sum of CP + EE in MW represented >80% DM, but with higher EE contents-CP: EE = 2.45. Data shows greater chitin content in crickets than BSFL + MW. Crickets showed greater neutral detergent fibre (NDF) than BSFL + MW; however, acid-detergent fibre (ADF) was similar among all species, suggesting NDF may include amalgams of interlinked nutrients released by acid digestion. This first study shows for the first time evidence that rearing conditions and substrates influences molecular structure. Exponential solubilisation was observed during pepsin + pancreatin digestion for all, but BSFL exhibited the highest degree-of-hydrolysis during the pancreatin phase, surpassing others. Analysis indicates protein hydrolysis differences are linked to trypsin activity susceptibility.

Determination of Phytase-hydrolyzable Phosphorus in Selected Animal Feed Ingredients by In Vitro Digestion Method

Feed phytase is one of the most successful biotechnological applications that led to better farm performance and effective phosphorus (P) reduction in animal excrement. Better estimation of phytase-hydrolyzable P (PHP) in feeds can further improve the estimation of animal rations for higher productivity. PHP in yellow corn, feed wheat, wheat pollard, rice bran, soybean meal, copra meal, and monodicalcium phosphate (MDCP) was determined by in vitro digestion. To determine if PHP values of feed ingredients are additive, three formulated diets were also subjected to the same method. The procedure consisted of phytase, pepsin, and pancreatin digestion periods – each of which simulated the different sections of poultry’s gastrointestinal tract. After these three incubations, the P contents in the dialysate and residual fluids – with and without enzyme – were analyzed. Results showed that yellow corn contained the highest PHP value with 52.54% of its total soluble P – followed by soybean meal, rice bran, copra meal, and feed wheat with 52.32, 39.86, 26.77, and 21.9%, respectively. Wheat pollard and MDCP had –58.47 and –2.63%, respectively. On the other hand, formulated diets 1, 2, and 3 contained actual PHPs of 32.3, 14.02, and 38.68% – as well as calculated values of 33.22, 29.13, and 40.1%, respectively. Statistical analyses showed no significant difference between the actual and calculated values. Therefore, PHP is additive when used in diet formulation. Lastly, comparing the P in the dialysate from the experiment and the available P present in the seven feed samples based on literature indicated that the experimental values were lower than those of the literature data for all samples. This discrepancy can be attributed to the type of samples analyzed; the experimental data were obtained upon in vitro assay of individual feeds, whereas the literature values were based on an as-fed basis, which may contain other components normally fed to animals.

A common edible insect (Antheraea assamensis) protein hydrolysate regulates LPS-induced oxidative stress and inflammation by modulating the TLR4/NF- κ β Signaling Pathway

Abstract Dietary intake of antioxidant and anti-inflammatory-rich foods is a growing approach for fighting inflammation and its associated disorders. Edible insects are gaining popularity as a food source; however, their therapeutic properties, anti-inflammatory activity and their mechanism of action remain largely unexplored. Herein, we evaluate the effectiveness of Antheraea assamensis pupae hydrolysates against oxidative stress and inflammation. The proteins isolated from the pupae were digested with pepsin or pancreatin, or pepsin + pancreatin and passed through a 30 kDa molecular cut-off membrane. The low molecular weight protein hydrolysates were characterised using RP-HPLC, HRMS, XRD, and FTIR-ATR. Hydrolysate from pepsin + pancreatin digestion showed significantly higher DPPH (77.13±2.57%), superoxide (72.08±1.15%) and hydroxyl (56.32±0.90%) radical scavenging activity in a cell-free system. Further, it reduced intercellular ROS production and suppressed the lipopolysaccharide-induced protein expression of TLR4, p-IKKβ, p-NF-, IL-1β, and COX2 in RAW 264.7 macrophages. Furthermore, it inhibited the secretion of pro-inflammatory mediators, including IL-6, IL-1β, and MIP-2. These findings suggest that A. assamensis pupae hydrolysates can be a potential source of bioactive peptides for managing oxidative stress and inflammation.

Slow-digestive yeast protein concentrate: An investigation of its in vitro digestibility and digestion behavior

Yeast protein concentrate, a by-product of the fermentation industry waste, is a potential alternative protein source with high nutritional quality, environmental sustainability, and functional properties. However, its digestibility and digestion behavior are poorly understood. In this study, we compared the in vitro digestion behavior of yeast protein concentrate and whey protein concentrate using simulated gastrointestinal conditions. We found that yeast protein concentrate had lower digestibility than whey protein concentrate (31.25% vs. 86.23% at 120 min of pepsin digestion and 75.12% vs. 95.2% at 120 min of pancreatin digestion). Yeast protein concentrate differed from whey protein concentrate in microstructure, secondary structure, and amino acid composition, which may affect its digestion behavior. Compared to whey protein concentrate, a higher level of β-sheets and a lower zeta potential explain the slow-digesting property of yeast protein concentrate. Yeast protein concentrate also underwent depolymerization and Plastein reaction during digestion. These results provided valuable information for developing and applying yeast protein concentrate as an alternative to conventional animal protein.

Insight into covalent conjugates of β-lactoglobulin with rutin: Characterizing allergenicity, digestibility, and antioxidant properties in vitro

β-lactoglobulin (β-LG) is an essential nutrient in milk, but it is the primary allergen causing dairy allergy in humans. Currently, researchers are focusing on using flavonoids to covalently modify β-LG for improving its functionality. However, the impact and underlying mechanisms of rutin covalent modification on the functional properties and allergenicity of β-LG remain unclear. Here, we aim to investigate the changes in allergenicity, digestive characteristics, and antioxidant properties of β-LG after covalent modification using a combination of spectroscopy, enzyme-linked immunosorbent assay (ELISA), simulated digestion, and antioxidant assays. The results indicate that rutin forms covalent bonds with the free amino group, sulfhydryl group, and tryptophan of β-LG, leading to alterations in the secondary structure of β-LG. Furthermore, the modified β-LG exhibits improved antioxidant capacity and decreased allergenicity, along with reduced resistance to pancreatin digestion in vitro. This study provides novel insights and strategies to expand the functional application of β-LG.

Effect of extrusion processing and simulated human digestion on the allergenicity of bambara groundnut protein

SummaryExtrusion has been reported as a method for reducing protein allergenicity. This study aimed to investigate the effect of extrusion on proteins contained in bambara groundnut flour on the allergenicity of the nut. Allergenicity could also be assessed after human digestion using simulated enzyme digestion. Bambara groundnut flour was extruded and followed by pepsin and pancreatin digestion. SDS‐PAGE, immunoblotting and ELISA were performed to reveal the protein profiles before and after extrusion and to locate the proteins with their IgE binding properties. Two bands following SDS‐PAGE at a similar range of molecular weight (11 and 13 kDa) were identified with the IgE binding in 4 of 10 human sera after the raw bambara groundnut flour was digested by the digestion enzymes. On the contrary, none of the protein bands was observed in its extruded flour, with or without simulated digestion treatment. ELISA analysis showed that the extrusion could decrease allergenicity by approximately 60%. After digestion, the allergenicity reduction of the extruded flour could reach 100%. Therefore, extrusion is a promising food processing method to reduce the allergenicity of bambara groundnut protein.

The degree of doneness affected molecular changes and protein digestibility of pork.

The degree of doneness has been shown to have a great impact on eating quality of meat, however, it is little known whether it affects protein digestibility of meat. In this study, we explored molecular changes and protein digestibility of pork under different degree of doneness. Pork chops were cooked in a 100°C water bath for about 26 min and a gradient decrease in doneness was obtained from outer to inner layers of samples. Compared with the raw samples, the cooked samples' active and total sulfhydryl contents, surface hydrophobicity, and turbidity increased but its solubility decreased. The inner layers with lower doneness contained higher α-helix, and fluorescence intensities of tryptophan and tyrosine residues than the outer layers with higher doneness. The pepsin and pancreatin digestibility of meat proteins in the inner layers were higher than those of the outer layers. Molecular simulation analysis showed that the most abundant protein in pork, i.e., myosin in the outer layers were more stable with an increased number of hydrogen bonds, making it difficult to be digested. These findings provided a new insight into the heterogeneity of meat nutritional quality due to the existence of doneness gradient.

Impact of Food Matrices on Digestibility of Allergens and Poorly Allergenic Homologs.

BackgroundProtease resistance is considered a risk factor for allergenicity of proteins, although the correlation is low. It is nonetheless a part of the weight-of-evidence approach, proposed by Codex, for assessing the allergenicity risk of novel food proteins. Susceptibility of proteins to pepsin is commonly tested with purified protein in solution.ObjectiveFood proteins are rarely consumed in purified form. Our aim was to evaluate the impact of experimental and endogenous food matrices on protease susceptibility of homologous protein pairs with different degrees of allergenicity.MethodsPorcine and shrimp tropomyosin (ST) were subjected to sequential exposure to amylase, pepsin, and pancreatin in their respective endogenous matrix (pork tenderloin/boiled shrimp) and in three different experimental matrices (dessert mousse [DM], soy milk [SM], and chocolate bar [CB]). Digestion was monitored by immunoblotting using tropomyosin-specific antibodies. Recombinant peach and strawberry lipid transfer protein were biotinylated, spiked into both peach and strawberry fruit pulp, and subjected to the same sequential digestion protocol. Digestion was monitored by immunoblotting using streptavidin for detection.ResultsChocolate bar, and to a lesser extent SM, had a clear protective effect against pepsin digestion of porcine tropomyosin (PT) and to a lesser extent of ST. Increased resistance was associated with increased protein content. Spiking experiments with bovine serum albumin (BSA) confirmed the protective effect of a protein-rich matrix. The two tropomyosins were both highly resistant to pepsin in their protein-rich and lean native food matrix. Pancreatin digestion remained rapid and complete, independent of the matrix. The fat-rich environment did not transfer protection against pepsin digestion. Spiking of recombinant peach and strawberry lipid transfer proteins into peach and strawberry pulp did not reveal any differential protective effect that could explain differences in allergenicity of both fruits.ConclusionsProtein-rich food matrices delay pepsin digestion by saturating the protease. This effect is most apparent for proteins that are highly pepsin susceptible in solution. The inclusion of food matrices does not help in understanding why some proteins are strong primary sensitizers while homologs are very poor allergens. Although for induction of symptoms in food allergic patients (elicitation), a protein-rich food matrix that may contribute to increased risk, our results indicate that the inclusion of food matrices in the weight-of-evidence approach for estimating the potential risks of novel proteins to become allergens (sensitization), is most likely of very limited value.

Evolution of in vitro digestibility techniques: a systematic review

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.

Phycocyanobilin-modified β-lactoglobulin exhibits increased antioxidant properties and stability to digestion and heating

β-lactoglobulin (BLG) is a major whey protein with numerous techno-functional properties desirable for the food industry. Phycocyanobilin (PCB), a bioactive pigment of Arthrospira platensis with health-promoting effects, covalently binds to BLG at physiological pH. This study investigated the effects of this covalent modification on BLG functional properties. The BLG–PCB adduct possesses enhanced antioxidant properties, and bound PCB protects BLG against free radical-induced oxidation. Despite the similar thermal stabilities of BLG and BLG–PCB, BLG–PCB is less susceptible to covalent and noncovalent aggregation under moderate heat treatment (63 °C, 30 min). Blocked thiol group and reduced hydrophobicity due to hindering of hydrophobic residues by bound PCB, as well as the heat-induced transition of β-sheet to α-helix, contributed to the low susceptibility of BLG–PCB to aggregation. BLG–PCB has a higher resistance to pepsin and pancreatin digestion than BLG and unaltered IgE-binding properties. The improved functional properties of BLG–PCB make it a useful ingredient in the food industry.

Physical-chemical properties and in vitro digestibility of phosphorylated and glycosylated soy protein isolate

Increased demand for highly functional soy protein isolate (SPI) in the food industry draws extra attention to SPI modification. The structural properties and in vitro digestibility of phosphorylated and glycosylated SPI were investigated in this study. The phosphorylation was carried out with sodium tripolyphosphate addition at 45 °C for 4 h. Glucose and dextran were used for glycosylation at 100 °C for 1 h. Apparent molecular weight distribution was determined by size exclusion-high performance liquid chromatography. Thiol content and surface hydrophobicity were also determined. The apparent molecular weight and thiol content of phosphorylated SPI increased with the increase of phosphorylation degree. Meanwhile, phosphorylation negatively affected gastrointestinal digestibility, especially gastric digestibility. The fraction of glycosylated SPI was prone to be low molecular weight, suggesting glycosylation inhibited SPI aggregation, which resulted from the attenuated surface hydrophobicity. The digestibility of SPI was increased by glycosylation. Glucose-based glycosylation contributed to lower intestinal digestion compared with dextran-based glycosylated SPI. This work highlighted that the phosphorylation and glycosylation to SPI primarily affected the in vitro pepsin or pancreatin digestion, inspiring to produce modified SPI with balanced functional and nutritional properties for the food industry.

Ultrasonic treatment increased functional properties and in vitro digestion of actomyosin complex during meat storage

We investigated the effects of ultrasonic treatment (400 W, 20 kHz, 45.52 W/L) and storage time (0 d, 3 d, 7 d and 10 d) on functional properties, structural changes and in vitro digestion of actomyosin complex isolated from vacuum-packed pork. As storage time increased, turbidity, surface hydrophobicity, active sulfhydryl and total sulfhydryl of actomyosin complex increased, while protein solubility decreased. Ultrasonic treatment increased surface hydrophobicity, protein solubility and active sulfhydryl content but decreased turbidity and total sulfhydryl content compared with the control. Ultrasonic treatment caused a reduction in α-helix content on 0 day and the fluorescence intensity of tryptophan and tyrosine residues. It increased pancreatin digestibility of actomyosin complex and the number of peptides of smaller than 1 kDa. However, it decreased the number of peptides. The findings provide a new insight into the application of appropriate ultrasonic treatment to promote meat digestibility.

Marine Fish Primary Hepatocyte Isolation and Culture: New Insights to Enzymatic Dissociation Pancreatin Digestion.

Primary cell cultures from wild organisms have been gaining relevance in ecotoxicology as they are considered more sensitive than immortalized cell lines and retain the biochemical pathways found in vivo. In this study, the efficacy of two methods for primary hepatocyte cell isolation was compared using liver from two marine fish (Sparus aurata and Psetta maxima): (i) two-step collagenase perfusion and (ii) pancreatin digestion with modifications. Cell cultures were incubated in L-15 medium at 17 ± 1 °C and monitored for up to six days for cell viability and function using the trypan blue exclusion test, MTT test, lactate dehydrogenase (LDH) activity, and ethoxyresorufin O-deethylase (EROD) activity after Benzo[a]Pyrene exposure. The results showed significant differences between the number of viable cells (p < 0.05), the highest number being obtained for the pancreatin digestion method (average = 4.5 ± 1.9 × 107 cells). Moreover, the hepatocytes showed solid adherence to the culture plate and the rounded shape, changing into a triangular/polygonal shape. The cell viability and function obtained by pancreatin digestion were maintained for five days, and the EROD induction after exposure to the B[a]P showed that cells were metabolically active. This study shows that the optimized pancreatin digestion method is a valid, cost-effective, and simple alternative to the standard perfusion method for the isolation of primary hepatocytes from fish and is suitable for ecotoxicological studies involving marine pollutants, such as PAHs.

Estimation of Degree of Hydrolysis of Protein Hydrolysates by Size Exclusion Chromatography

Estimating the degree of hydrolysis (DH) of commercial protein hydrolysates from their molecular weight (MW) median values generated by high performance size exclusion chromatography with UV detection (HPSEC/UV) was evaluated. DH is defined as the proportion (%) of cleaved peptide bonds in a protein hydrolysate. Several methods for DH determination are available, and protein hydrolysates are often tested both for DH by one of these methods and for MW profile by an HPSEC/UV method. We describe a means of estimating the DH of a protein hydrolysate from its MW profile, thereby eliminating the need for the performance of a second, separate test. In this study, a plot of average DH (%) vs. MW median (Da) was constructed from pancreatin digestion time data for seven protein substrates, determined by an HPSEC/UV system with a peptide gel filtration column. A general formula obtained from the plot enables DH estimation for a protein hydrolysate from its MW median value. By using this approach, the DH values for a total of thirteen commercial protein hydrolysates derived from whey, casein, and soy were estimated. Method accuracy was assessed by comparing the MW median-estimated DH to the DH determined by TNBS colorimetry, which generally agreed well, with R2 > 0.95. This study demonstrated that a reliable estimate of protein hydrolysate DH may be obtained from its MW median so that the performance of a separate DH test may not be necessary.

Characterization of probiotic Enterococcus lactis RS5 and purification of antibiofilm enterocin

Abstract Enterocin R5 is an antibacterial peptide found in the culture supernatant of Enterococcus lactis RS5 with a broad spectrum activity. The RS5 was isolated from a marine fish, Sillago indica. Enterocin R5 inhibited Staphylococcus aureus, Salmonella enterica ser. Typhi, Proteus vulgaris, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Bacillus cereus. Furthermore, bacteriocin gene cluster characterization showed 70–85% amino acid similarity to the class II bacteriocin from Enterococcus species. The bioactive cell-free supernatant was purified by bio-active guided column chromatography followed by SDS-PAGE analysis revealed that the presence of enterocin with a molecular mass of approximately 6 kDa. The probiotic E. lactis RS5 characterization suggest that tolerance to bile salt, low pH and pancreatin digestion. Moreover, enterocin R5 exhibited more than 60% anti-biofilm activity against biofilm forming food spoilage bacteria at 100 μg/ml concentration. Therefore, this enterocin R5 has potential to be used as an alternative antibacterial agent for the treatment of biofilm-associated food spoilage pathogens.

The effects of Sestrin2 on apoptosis of heat-exposed lung epithelial cells and its mechanism

To investigate the protective effects of Sestrin2 protein on lung epithelial Beas-2B cells in the heat-exposure environment and its mechanism. Lung epithelial Beas-2B cells were cultured at 37℃, 39℃, 40℃ and 41℃ respectively. Cells were harvested at different times (0, 3, 6 and 12 h) after pancreatin digestion. The expressions of Sestrin2, superoxide dismutase(SOD), reactive oxygen species(ROS), cell mitochondrial membrane potential and apoptosis rate of cells were detected by Western blot, fluorescence spectrophotometer and flow cytometry, respectively. Gene expression sequence was cloned into high expression plasmid pcDNA3.1+. Beas-2B cells were transfected by Lipfectamine 2000 to construct Sestrin2 and SOD high expression cells. The changes of mitochondrial membrane potential and cell apoptosis were observed in the Sestrin2 and SOD high expression cells. With the increase of temperature, the expression level of Sestrin2 protein in heat treatment group was decreased compared with the control group. When Beas-2B cells were exposed to 41℃, the ROS level was increased, mitochondrial membrane potential was decreased significantly and apoptosis rate was increased at different time points. After high expression of Sestrin2 and SOD in the Beas-2B cells, the expression level of ROS was decreased and the change tendency of mitochondrial membrane potential was decreased, and the apoptosis rate was reduced at 41℃ exposure. Sestrin2 can alleviate the apoptosis of lung epithelial cells induced by heat exposure through mitochondrial membrane potential and SOD, which has protective effect on lung epithelial Beas-2B cells.

Improved in vitro digestibility of rapeseed napin proteins in mixtures with bovine beta-lactoglobulin.

Mixing of different protein sources can lead to either predictable, synergistic, or antagonistic effects on the protein digestibility. This study investigated the in vitro protein digestibility (IVPD) of protein mixtures between a napin-rich rapeseed (Brassica napus L.) protein concentrate (RP2) and bovine milk whey proteins (WPs; α-LA, alpha-lactalbumin; β-LG, beta-lactoglobulin) at mixing ratios of 20:80, 40:60, 60:40, and 80:20 w/w protein. Enzymatic hydrolysis consisted of pepsin digestion (1 h) followed by short- (+1 h), medium- (+3 h), or long-term (+24 h) pancreatin digestion. IVPD was differentially affected by the WPs type, mixing ratios, and total hydrolysis times. RP2/β-LG protein mixtures showed a partially synergistic effect at mixing ratios of 40:60 and 60:40 w/w, leading to an increased short-term IVPD of 7-10%. LC-MS analysis revealed a markedly improved short-term digestibility of the napin proteins when combined with bovine β-LG. This study demonstrated that specific mixtures between animal and plant protein sources exhibit an improved digestibility due to synergistic protein-protein interactions.

PTEN suppresses the inflammation, viability, and motility of AP-AR42J cells by activating the Wnt/β-catenin pathway.

Acute pancreatitis (AP), a kind of common acute abdominal disease and typical chemical inflammation, is commonly caused by pancreatin digestion of the pancreas and surrounding tissues. The gene for phosphate and tension homology deleted on chromosome ten (PTEN) is a tumor suppressor that regulates numerous cellular processes. In the present study, we have elaborately investigated the effect of PTEN on the alleviating of AP and its underlying mechanisms. Firstly, we demonstrated an up-regulation of PTEN in the pancreatic tissues from AP rats by immunochemistry, qRT-PCR and western-blot assays. Subsequently, cellular experiments exhibited that PTEN has a significant inhibition effect on the proliferation, invasion and migration of AP cells. Further underlying mechanism studies showed that the growth of AP cells was mainly restrained by PTEN in the G1 phase through activation of the Wnt/β-catenin pathway, which can be demonstrated by the down-regulation of various pro-inflammatory cytokines such as IL-6, IL-10, TNF and IL-1β. Taking these results together, we can draw the conclusion that PTEN plays a significant role in suppressing the inflammation, viability and motility of acute pancreatitis and could be a potential target for AP therapies.

Design and characterization of mangiferin nanoparticles for oral delivery

Mangiferin, a bioactive compound with numerous therapeutic properties was extracted from Curcuma amada. To solve the bioavailability issues of mangiferin, it was encapsulated in β-lactoglobulin (β-LG), by desolvation method and reduced to a nano size. From the Dynamic Light Scattering (DLS) data, average particle size and zeta potential of the nanoparticle was 89 ± 10 nm and −30.0 ± 0.2 mV respectively. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) results illustrated the spherical and uniform size (approximately 70 nm) of the nanoparticles. The release kinetics of mangiferin by simulated gastrointestinal (GI) studies demonstrated more resistance of nanoparticles towards pepsin digestion in comparison with pancreatin digestion. Release of mangiferin observed in colon fluid was 80%. In vitro release kinetics, by Kopcha model, predicted that the mangiferin release from the nanoparticles follows a non-Fickian process. The Baker–Lonsdale model further predicted the spherical shape of the nanoparticles. The nanoparticles can be stored for 30 days at 4 °C retaining its activity. DPPH assay proved that nanoencapsulation of mangiferin retained the antioxidant property. Nanoparticles demonstrated anti-microbial activity against Staphylococcus aureus and Escherichia coli. No toxicity was observed towards the useful probiotic strain of gastrointestinal tract. The study could establish that the mangiferin/β-lactoglobulin nanoparticles might be a promising candidate for oral delivery.