Enzymatic Activity Of Trypsin Research Articles

Enzyme inhibitory potency of nano formulation of some plant oils on the red palm weevil Rhynchophorus ferrugineus olivier

Inhibitory effect of the tested plant oils and their nanoformulation against trypsin and chymotrypsin enzyme extracted from Rhynchophorus ferrugineus, was studies in in vivo and in vitro. In vivo inhibition, the reduction in the trypsin specific activity caused by the bulk oils was greater than that of chymotrypsin enzyme. Compared to control nanoformulation caused significant reduction in the specific activity of trypsin enzyme; however, there were no inhibition effect observed on chymotrypsin enzyme. In vitro bulk oils showed very low inhibitory effect against trypsin enzyme, while they showed strong inhibition activity against chymotrypsin with recording for ginger nanoformulation (half-maximal inhibitory concentration (IC50) =6.83 μg/ml), purple nutsedge (7.632 μg/ml), garden cress (11.52 μg/ml) and castor (16.82 μg/ml), nanoformulation of these oils showed uncompetitive type of inhibition as the Vmax and Km values changed compared to control. In conclusion, nanoformulation of the tested plant oils could be used in the integrated pest management (IPM) programs of the red palm weevil (RPW).

MiR-455-3p ameliorates pancreatic acinar cell injury by targeting Slc2a1.

With the number of patients with acute pancreatitis (AP) increasing year by year, it is pressing to explore new key genes and markers for the treatment of AP. miR-455-3p/solute carrier family 2 member 1 (Slc2a1) obtained through bioinformatics analysis may participate in the progression of AP. The C57BL/6 mouse model of AP was constructed for subsequent studies. Through bioinformatics analysis, the differentially expressed genes related to AP were screened and hub genes were identified. A caerulein-induced AP animal model was constructed to detect the pathological changes of mouse pancreas by HE staining. The concentrations of amylase and lipase were measured. Primary mouse pancreatic acinar cells were isolated and subjected to microscopy to observe their morphology. The enzymatic activities of trypsin and amylase were detected. The secretion of inflammatory cytokines in mouse were measured with the ELISA kits of TNF-α, IL-6 and IL-1β to determine pancreatic acinar cell damage. A binding site between the Slc2a1 3' UTR region and the miR-455-3p sequence was verified by dual-luciferase reporter assay. The expression of miR-455-3p was quantified by qRT-PCR, and Slc2a1 were detected by western blot. A total of five (Fyn, Gadd45a, Sdc1, Slc2a1, and Src) were identified by bioinformatics analysis, and miR-455-3p/Slc2a1 were further studied. HE staining results showed that the AP models were successfully established by caerulein induction. In mice with AP, the expression of miR-455-3p was reduced, while that of Slc2a1 was increased. In the caerulein-induced cell model, the expression of Slc2a1 was significantly reduced after intervention of miR-455-3p mimics, whereas increased after miR-455-3p inhibitor treatment. miR-455-3p decreased the secretion of inflammatory cytokines in the cell supernatant, reduced the activity of trypsin and amylase, and alleviated the cell damage induced by caerulein. In addition, Slc2a1 3'UTR region was bound by miR-455-3p, and its protein expression was also regulated. miR-455-3p alleviated caerulein-induced mouse pancreatic acinar cell damage by regulating the expression of Slc2a1.

Will ocean acidification affect the digestive physiology and gut microbiota of whelk Brunneifusus ternatanus?

To understand the physiological responses of the Brunneifusus ternatanus to future ocean acidification (OA), histology, enzyme activity and gut bacterial composition at different pH levels (Control: C group, pH 8.1; Exposure period: EP group, pH 7.3) for 28 days were studied under laboratory conditions. Microbiota composition was analyzed using 16S rRNA gene amplicon sequencing. Enzyme activities of trypsin (TRY), lipase (LPS), amylase (AMS), and lysozyme (LZM) were used as biochemical indicators, as well as weight gain rate (WGR), specific growth rate (SGR) as growth indicators. The stress caused by OA resulted in alterations to the intestine, including partially swollen and degranulated enterocytes and rough endoplasmic reticulum (RER). The relative abundance of the core phylum in the acidified group changed significantly, showing an increase in Tenericutes and a decrease in Proteobacteria. Firmicutes/Bacteroides ratio declined from 4.38 in the control group to 1.25 in the EP group. We found that the enzymes TRY, LPS, and AMS activities were inhibited at reduced pH, which was positively correlated with the dominant genera Mycoplasma and Bacteroides; while LZM activities showed a significant increment, but showing a strong negative correlation. Furthermore, both WG and SRG values showed a depression at low pH lever. These results suggest that if anthropogenic CO2 emissions continue to accelerate, OA could negatively impact the whelk’s health, compromising their growth performance and even survival. These findings will benefit the future risk assessments of OA or other related emerging environmental issues.

Will ocean acidification affect the digestive physiology and gut microbiota of whelk Brunneifusus ternatanus?

To understand the physiological responses of the Brunneifusus ternatanus to future ocean acidification (OA), histology, enzyme activity and gut bacterial composition at different pH levels (Control : C group, pH 8.1; Exposure period : EP group, pH 7.3) for 28 days were studied under laboratory conditions. Microbiota composition was analyzed using 16S rRNA gene amplicon sequencing. Enzyme activities of trypsin (TRY), lipase (LPS), amylase (AMS), and lysozyme (LZM) were used as biochemical indicators, as well as weight gain rate (WGR), specific growth rate (SGR) as growth indicators. The stress caused by OA resulted in alterations to the intestine, including partially swollen and degranulated enterocytes and rough endoplasmic reticulum (RER). The relative abundance of the core phylum in the acidified group changed significantly, showing an increase in Tenericutes and a decrease in Proteobacteria. Firmicutes/Bacteroides ratio declined from 4.38 in the control group to 1.25 in the EP group. We found that the enzymes TRY, LPS, and AMS activities were inhibited at reduced pH, which was positively correlated with the dominant genera Mycoplasma and Bacteroides; while LZM activities showed a significant increment, but showing a strong negative correlation. Furthermore, both WG and SRG values showed a depression at low pH lever. These results suggest that if anthropogenic CO2 emissions continue to accelerate, OA could lead to a negative impact on the whelk health, also compromising their growth performance and even survival. These findings will benefit the future risk assessments of OA or other related emerging environmental issue.

Trypsin, the Major Proteolytic Enzyme for Blood Digestion in the Mosquito Midgut.

When a female mosquito takes a blood meal, proteolytic activity surges in the midgut. Trypsin-like serine proteases are the major endoproteolytic enzyme induced by feeding in mosquitoes. The mosquito midgut lacks trypsin activity before the blood meal, but in most anautogenous mosquitoes, trypsin activity increases continuously up to 30 h after feeding and subsequently returns to baseline levels by 60 h. Trypsin activity in mosquitoes is restricted entirely to the posterior midgut lumen, where blood is stored and digested. Trypsin enzyme activity can be quantitatively measured using the artificial Nα-benzoyl-DL-arginine 4-nitroanilide hydrochloride substrate, a method described in our associated protocol.

PDMS networks meet barnacles: a complex and often toxic relationship

The biological impact of chemical formulations used in various coating applications is essential in guiding the development of new materials that directly contact living organisms. To illustrate this point, an investigation addressing the impact of chemical compositions of polydimethylsiloxane networks on a common platform for foul-release biofouling management coatings was conducted. The acute toxicity of network components to barnacle larvae, the impacts of aqueous extracts of crosslinker, silicones and organometallic catalyst on trypsin enzymatic activity, and the impact of assembled networks on barnacle adhesion was evaluated. The outcomes of the study indicate that all components used in the formulation of the silicone network alter trypsin enzymatic activity and have a range of acute toxicity to barnacle larvae. Also, the adhesion strength of barnacles attached to PDMS networks correlates to the network formulation protocol. This information can be used to assess action mechanisms and risk–benefit analysis of PDMS networks.

Investigation on conformational variation and enzymatic activity of trypsin affected by Ti3C2 QDs via spectroscopic technique and molecular modeling

In this paper, Ti3C2 quantum dots (Ti3C2 QDs) were synthesized by simply treating Ti3C2 MXene powder with acid and base via hydrothermal method. Ti3C2 QDs exhibited superior fluorescence property and were used for the fluorescent imaging of living HeLa cells successfully. In order to evaluate the influence of Ti3C2 QDs on protease with specific biological functions, binding interaction of Ti3C2 QDs with trypsin was studied comprehensively and deeply through spectroscopic strategies and molecular modeling technique. The intrinsic fluorescence of trypsin was spontaneously quenched by Ti3C2 QDs through static quenching mode under van der Waals interaction force, and Ti3C2 QDs bound with the inactive residue domain of trypsin firmly with stoichiometric ratio of 1:1. Ti3C2 QDs induced the microenvironmental variation of the amino acid residues in trypsin, reducing the thermal stability of trypsin significantly. Gel electrophoresis experiments and microscopic imaging experiments demonstrated that Ti3C2 QDs inhibited the enzymatic activity of trypsin on the digestion of human serum albumin and HeLa cells obviously. These results revealed not only the deep interaction mechanism between Ti3C2 QDs and protease but also the influence of Ti3C2 QDs on the enzymatic activity of trypsin, paving the way for the safe biological application of Ti3C2 QDs in the diagnosis and the therapy of protease-related diseases.

Response of Gut Microbiota, Digestive Enzyme Ability, and Immune Function to Starvation in the Oriental River Prawn Macrobrachium nipponense

In order to evaluate the interplay of nutritional status and the digestive capacity, immune function, and gut microbiota in the oriental river prawn Macrobrachium nipponense, a 14-day starvation trial was conducted to detect the effects of starvation on the activities of digestive enzymes and immune enzymes and the structure of prawn gut microbiota. The adult prawns were randomly assigned to a control group (F group) and starvation group (S group) with three replicates. The F group was normally fed with commercial diet, and the S group was starved for 14 days. The result showed that digestive enzyme activities of trypsin and lipase in the hepatopancreas of the S group were significantly lower than those of the F group after 4 d of starvation ( P < 0.05 ), while the activity of amylase significantly increased after 14 d of starvation ( P < 0.05 ). Moreover, the results of the histological analysis of prawn gut showed that both the height of epithelial cells and microvilli of intestine in the S group were obviously decreased than those in the F group ( P < 0.05 ) after 14 d of starvation. The activities of immune-related enzymes including superoxide dismutase, catalase, and acid phosphatase in the hepatopancreas of the S group significantly decreased after 4 d of starvation, and lysozyme activity of the F group was lower than that of the S group after 7 d of starvation ( P < 0.05 ). In addition, the results of Illumina high-throughput sequencing showed that a total of 14,285 OTUs were obtained and classified into 30 phyla, among which Actinobacteria and Proteobacteria were the predominant microflora in the intestinal microbial communities of both groups. However, the relative abundance of opportunistic pathogens was significantly increased in the S group, while the relative abundance of beneficial bacterium was decreased ( P < 0.05 ). The bacterial richness with the Chao estimator was significantly higher in the F group than in the S group ( P < 0.05 ). Both the results of principal coordinate analysis (PCoA) and nonmetric multidimensional scaling (NMDS) demonstrated that the intestinal microbiota of the F group was separate from those of the S group. The result of functional prediction of the metabolic pathways showed that the intestinal microbiota was enriched in the KEGG pathways of amino acid, carbohydrate, fatty acid, and lipid biosynthesis and degradation at level 2. This result implied that the microbiota of shrimp gut decreased nutrition metabolism under the stress of starvation. Meanwhile, comparing to the F group, the immune-related pathway of enterobacterial common antigen biosynthesis was markedly reduced in the S group ( P < 0.05 ). The result of redundancy analysis (RDA) further confirmed that the activities of digestive and immune enzymes were correlated with the microbial community structure. Finally, the structural equation modeling highlighted that changes in the activities of digestive and immune enzymes were directly related to the gut bacterial community and notably affected prawn growth.

Combined toxicity and toxicity persistence of antidepressants citalopram and mirtazapine to zooplankton Daphnia magna.

Citalopram (CTP) and mirtazapine (MTP) are two typical psychoactive drugs used for the depression treatment. As emerging pollutants, CTP and MTP have raised concern because of their harmful effect on aquatic organisms. Therefore, the ecotoxicological risk of these two pollutants to aquatic organisms should be given more attention. In this study, the effects of CTP and MTP on the feeding rate, heartbeat, nutritional enzymes, and their related gene expression of D. magna were investigated under single and binary mixture pollutant exposure. Subsequently, the recovery of exposed D. magna was studied to assess the toxic persistence of those pollutants. After 24-h exposure, the ingestion rate decreased by 34.2% and 21.5%, in the group of 1.45mg/L CTP (C-H) and binary mixture with high concentration (Mix-H), respectively. After 24-h recovery, the feeding rate of D. magna was stimulated by a compensatory response. Over the exposure period, the heartbeat rate of D. magna increased significantly in the groups of CTP, MTP, and their binary mixture with low concentration (Mix-L), and then, their heartbeat rate was recovered during the recovery period. The activity of α-amylase (AMS) and trypsin were significantly changed in most of the exposed daphnia, both during the exposure and recovery period. CTP/MTP exposure stimulated the expression of the AMS gene. MTP and Mix-H exposure inhibited the expression of the trypsin gene and the other groups stimulated its expression. After 24-h recovery, the stimulating or inhibitory effects were alleviated. There were different responses between gene expression and enzyme activity. In conclusion, our results highlighted the toxic effects at high concentrations of single and mixed pollution of CTP and MTP on the feeding rate, heartbeat, AMS and trypsin enzyme activity, and expression of related genes of D. magna to assess the environment risk of them.

Arginine-containing dipeptides decrease affinity of gut trypsins and compromise soybean pest development

The design and production of molecules capable of mimicking the binding or/and functional sites of proteins inhibitors represent a promising strategy for the exploration and modulation of gut trypsin function in insect pests, specifically Lepidoptera. Here, for the first time, we characterized the trypsin activity present in the gut, performance and development of Anticarsia gemmatalis (Lepidoptera: Noctuidae) larvae when exposed to arginine-containing dipeptides. In silico assessment showed that arginine-containing dipeptides have a greater affinity for the active site of A. gemmatalis trypsins than lysine-containing peptides due to the presence of the double-charged guanidinium group that enhances the interaction at the S1 subsite of trypsins. Furthermore, the inhibitory and anti-insect potential of the peptides was demonstrated through kinetic and larval life cycle parameters, respectively. These dipeptides showed structural stability, binding to the active site, corroborated in vitro (competitive inhibition), and significant reduction of trypsin enzyme activity in the gut, survival, and weight of the A. gemmatalis larvae. Our findings reinforce the idea that small peptides are promising candidates for lepidopteran pest management. The optimization of DI2 and DI1 peptides, enhancing uptake and affinity to trypsins, may turn the use of these molecules feasible in agriculture.

Atividade inseticida de um inibidor de peptidase das sementes de Anadenanthera macrocarpa contra Anagasta kuehniella

ABSTRACT Protease inhibitors (PIs) are a part of the plant defense system and reduce the proteolytic activity of the digestive enzymes of insect pests. The current study aimed to isolate and characterize an inhibitor of trypsin (AmTI) within the seed of Anadenanthera macrocarpa (Benth) (Leguminosae-Mimosoideae). Moreover, we tried to assess the defense mechanism of the larvae of Anagasta kuehniella against this inhibitor. Protein seed extracts were purified using Sephadex G-50 and trypsin-Sepharose columns. Electrophoresis revealed the molecular weight of the inhibitor to be 25 kDa. The stability evaluation demonstrated that the inhibitor was not denatured at temperatures of up to 60 °C, pH 2-10, and concentrations of up to 100 mM dithiothreitol for one hour. The inhibitor reacted in a 1:1 ratio with bovine trypsin with an inhibition constant [Ki] = 2.517 ´ 10-8. Incorporating the inhibitor in a 1 mg per 100 mg proportion of artificial diet offered to A. kuehniella larvae led to a significant difference in the weight and survival of larvae of the fourth instar compared to the control. AmTI acted on the enzymatic activities of trypsin and chymotrypsin, not allowing until the fourth larval instar, A. kuehniella, to create adaptations against the inhibitor, as it had a simultaneous effect on larval weight and mortality. Therefore, a new trypsin inhibitor showing inhibitory activity against the digestive enzymes trypsin and chymotrypsin from A. kuehniella was isolated, indicating that these activities are correlated with the deleterious effects of this insect.

In Vitro Investigations on Optimizing and Nebulization of IVT-mRNA Formulations for Potential Pulmonary-Based Alpha-1-Antitrypsin Deficiency Treatment.

In vitro-transcribed (IVT) mRNA has come into focus in recent years as a potential therapeutic approach for the treatment of genetic diseases. The nebulized formulations of IVT-mRNA-encoding alpha-1-antitrypsin (A1AT-mRNA) would be a highly acceptable and tolerable remedy for the protein replacement therapy for alpha-1-antitrypsin deficiency in the future. Here we show that lipoplexes containing A1AT-mRNA prepared in optimum conditions could successfully transfect human bronchial epithelial cells without significant toxicity. A reduction in transfection efficiency was observed for aerosolized lipoplexes that can be partially overcome by increasing the initial number of components. A1AT produced from cells transfected by nebulized A1AT-mRNA lipoplexes is functional and could successfully inhibit the enzyme activity of trypsin as well as elastase. Our data indicate that aerosolization of A1AT-mRNA therapy constitutes a potentially powerful means to transfect airway epithelial cells with the purpose of producing functional A1AT, while bringing along the unique advantages of IVT-mRNA.

Preliminary investigation on enzymatic activity in saliva of Hystrix cristata L., 1758.

Mammal's saliva contains a variety of electrolytes and proteins. They carry out an important role in the digestion process, in the antibacterial and antiviral activity, in lubrication and maintenance of oral general health status. It may also contain several enzymes according to dietary habits and general wellness. Sialochemistry is a valid alternative to the haematochemical analysis for the evaluation of animal health and nutritional status. At present, very little knowledge is available on health status and pathology of crested porcupine (Hystrix cristata) and no data are yet available on salivary enzymes. Between 2018 and 2020, a preliminary investigation of enzymatic activity on saliva samples was carried out from captured porcupines. In crested porcupine saliva, enzymatic activity of trypsin, chymotrypsin, N-Aminopeptidase, amylase, lignin peroxidise, cellulase and chitinase were recorded. Superoxide dismutase, catalase, glutathione S-transferase and alkaline phosphatase activity was also detected. The superoxide dismutase activity resulted higher (3.13 SD 3.58U/mg proteins) than those of catalase (130.80 SD 110.65mU/mg proteins) and glutathione S-transferase (20.21 SD 16.62mM/mg proteins). Alkaline phosphatase activity resulted lower (5.91 SD 6.12mU/mg proteins) than acidic phosphatase (19.00 SD 16.16U/mg proteins) with the highest values of saliva alkaline phosphatases recorded in young individuals. These preliminary data bring new knowledge on crested porcupine saliva enzymes and may provide a useful tool for further investigation on the adaptive response of crested porcupine to different environmental condition and diet. Additional investigation concerning a possible alternative use of saliva enzymes as indicator of health and nutritional status of this rodent are desirable.

Combined effect of Spirulina and ferrous fumarate on growth parameters, pigmentation, digestive enzyme activity, antioxidant enzyme activity and fatty acids composition of Yellow River carp (Cyprinus carpio)

This study was conducted to investigate the effects of Spirulina and ferrous fumarate supplementations into diets on growth parameters, pigmentation, digestive enzyme activity, antioxidant enzyme activity and fatty acids composition of Yellow River carp. Three experimental groups included control, Spirulina (diet 1), mixture of Spirulina and ferrous fumarate treatments (diet 2) in 3 replications in 9 aquariums. Fifteen fish in each aquarium were fed twice a day for six weeks. Compared to the control group, the Yellow River carp fed with the Spirulina and ferrous fumarate had a higher specific growth rate (P < 0.05). The total carotenoids content in Yellow River carp skin and scale was significantly higher for fish fed diet with Spirulina and ferrous fumarate relative to all other diets (P < 0.05). The color parameters of L *, a *, b*, Hue (Hab°) and Chroma (ch*) were calculated for all treatments. Obtain findings revealed that the Spirulina and ferrous fumarate treatment could provide the desired skin color exactly of Yellow River carp. The Spirulina and ferrous fumarate supplementation significantly elevated intestinal digestive capacity by increasing amylase, lipase, and trypsin enzyme activities (P < 0.05). The results obtained indicated that Spirulina and ferrous fumarate supplementation could improve intestinal health through enhancing intestinal digestive enzyme activity and reducing tissue peroxidation. In addition, the Spirulina and ferrous fumarate has a satisfactory nutritional value of improving the fatty acid profile. Therefore, the use of Spirulina and ferrous fumarate as feed additive could be practiced in the aquaculture species.

Effects of inhibitors on the protease profiles and degradation of activated Cry toxins in larval midgut juices of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

Midgut juice plays an important role in food digestion and detoxification in insects. In order to understand the potential of midgut juice of Cnaphalocrocis medinalis (Guenée) to degrade Bt proteins, the enzymatic activity of midgut juice and its degradation of Bt proteins (Cry2A, Cry1C, Cry1Aa, and Cry1Ac) were evaluated in this study through protease inhibitor treatments. The activities of total protease in midgut juices were significantly inhibited by phenylmethylsulfonyl fluoride (PMSF), tosyl-L-lysine chloromethyl ketone (TLCK), pepstatin A and leupeptin. The enzymatic activity of chymotrypsin was significantly inhibited by PMSF, and enzymatic activity of trypsin was significantly inhibited by ethylenediaminetetraacetic acid (EDTA), PMSF, tosyl phenylalanine chloromethyl ketone (TPCK), TLCK and trans-epoxysuccinyl-L-leucylamido-(4-guanidino) butane (E-64). EDTA could significantly inhibit the degradation of Cry2A by C. medinalis. EDTA, PMSF, TPCK, and TLCK could inhibit the degradation of Cry1C and Cry1Aa. EDTA, PMSF, TPCK, TLCK, and E-64 could inhibit the degradation of Cry1Ac. Our results indicated that some protease inhibitors hindered various enzymatic activities in the larval midgut of C. medinalis, which may reduce the insect's ability to degrade Bt toxins. These findings may aid the application of protease inhibitors in the management of this insect pest in the future.

Mechanisms by Which Fermented Soybean Meal and Soybean Meal Induced Enteritis in Marine Fish Juvenile Pearl Gentian Grouper.

Soy meals can cause intestinal inflammation and even injury in animals, especially infants and juvenile individuals. This study investigated the effects of fermented soybean meal (FSBM) on the growth and intestinal homeostasis of juvenile pearl gentian grouper and examined the mechanisms by which FSBM and soybean meal (SBM) induced enteritis in fish, using “3+2” full-length transcriptome sequencing. We randomly assigned 720 female juvenile groupers into three treatment groups: FM control group, 20% FSBM group (FSBM20), and FSBM40 group (n = 4). Three iso-nitrogenous (50% protein) and iso-lipidic (10% lipid) diets were prepared and fed to fish for 10 weeks. The water volume in each barrel was about 1 m3, using natural light and temperature. Results showed that dietary FSBM, at experimental level, significantly affected fish growth and intestinal structure negatively and significantly increased enteritis indices. The degree of intestinal injury and inflammation was determined by the enzyme activities of trypsin and lysozyme, and the contents of IgM, C3, C4, and malondialdehyde, and the expressions of pro-inflammatory genes (IL1β, IL8, IL17, and TNFα) and anti-inflammatory genes (IL4, IL10, and TGFβ1). Full-length transcriptome analysis identified 2,305 and 3,462 differentially expressed genes (DEGs) in SBM40 and FSBM40 groups, respectively. However, only 18.98% (920/5,445) of DEGs had similar expression patterns, indicating that high levels of SBM40 and FSBM40 have different metabolic strategies. KEGG enrichment analysis indicated that among the significant pathways, ~45% were related to immune diseases/systems, infectious diseases, and signal transduction in both SBM and FSBM groups. Based on PacBio SMRT sequencing, nine toll-like receptor (TLR) members, including TLR1, TLR2, TLR3, TLR5, TLR8, TLR9, TLR13, TLR21, and TLR22, were detected in intestinal tissues of pearl gentian grouper. TLR-MyD88-NF-κB signaling pathway played an important role in the development of FSBM- and SBM-induced enteritis in pearl gentian grouper; however, TLR receptors used in SBM and FSBM groups were different. TLR1, TLR8, TLR13, and TLR22 were the main receptors used in FSBM group, while TLR5, TLR8, TLR9, TLR21, and TLR22 were the main receptors used in SBM group. Present study provides valuable theoretical references for further research on soy protein-induced enteritis in fish.

Immune and proteomic responses to the soybean meal diet in skin and intestine mucus of Atlantic salmon ( Salmo salar L.)

The main objective of this study was to increase the knowledge about the mucosal immunity of Salmo salar, using soybean meal-induced enteritis as a model of inflammation. A control fish meal (FM) and a diet containing 20% soybean meal (SBM) were fed to salmon for seven weeks in seawater. There was no growth difference between groups. However, histology of distal intestine (DI) showed a mild inflammation in the fish fed SBM. Proteomic results revealed differences between the diets. Among the proteins detected uniquely in DI mucus of SBM group, complement C5, Galectin and Glutathione synthetase are involved in innate and adaptive immunity, inflammation, redox signalling and detoxification of xenobiotics in mammals, and similar roles are hypothesized in salmon. Adenylosuccinate synthetase and putative aminopeptidase were uniquely detected in the skin mucus of SBM group. Trypsin enzymatic activity was significantly decreased in the DI of SBM group. Significantly higher production of immunoglobulin M and Mucin-like protein in DI mucus in SBM group was observed, while an increase in immunoglobulin D and lysozyme but decrease in chymotrypsin was detected in the skin mucus of the same group. We propose mucosal immunoglobulins as diagnostic biomarkers for assessment of novel feed ingredients and aquafeeds.

Effects of fish meal under different storage conditions on growth, serum biochemical indices and antioxidant capacity for juvenile grouper Epinephelus coioides

This research aimed to assess effects of fish meal under different storage conditions on growth and antioxidant capacity for juvenile grouper within eight weeks. The healthy fish samples (initial body weight = 18.75 ± 0.05 g) were irregularly distributed to 0.5 m3 barrels with 28 fish per barrel, fed with each diet in the three replicate groups. Fish meals (FMs) were stored at 4°C (experiment 1) and room temperature (30 ± 2°C, experiment 2) for 45, 90 and 135 days, and the data of VBN, HA, AV and TBA were detected. Seven iso-nitrogenous and iso-lipidic diets were prepared and denoted as fresh fish meal FFM (control group), 4-FM45, 4-FM90, 4-FM135, RT-FM45, RT-FM90 and RT-FM135, respectively. Prolonged storage time, the volatile base nitrogen, acid value, histamine and thiobarbituric acid contents of FM increased significantly (p < .05). The growth condition and feed utilization of experimental fish were not significantly affected (p > .05). Prolonged storage time, in experiment 1, the catalase (CAT), the superoxide dismutase (SOD) activities and the malondialdehyde (MDA) contents initially increased dramatically and then decreased (p < .05). The reactivity of CAT mRNA in FFM group was significantly higher than that in other treatment groups (p < .05). In experiment 2, CAT activity decreased significantly (p < .05), whereas the MDA contents increased sharply (p < .05). SOD activity and CAT expression in the liver initially increased and then decreased (p < .05). The mRNA level and enzyme activity of trypsin decreased (p < .05) in experiment 1 and 2. In summary, storage of FM (within 135 days) cannot improve the growth and feed utilization of juvenile grouper but weaken the antioxidant capacity of the liver.

Unravelling the effects of procyanidin on gliadin digestion and immunogenicity.

The effect of procyanidin dimer B3, a common food tannin, on the digestion of gliadin proteins was investigated by monitoring the changes in the immunogenic peptides produced during in vitro digestion and immunoreactivity. Interaction studies between procyanidin dimer B3, gluten proteins and/or digestive enzymes were performed by SDS-PAGE. The effect of procyanidin B3 on the enzymatic activity of trypsin, chymotrypsin and pancreatin was evaluated. The differences in the number and nature of immunogenic peptides released during digestion were identified by mass spectrometry. Briefly, the enzymatic activity of gastrointestinal enzymes was only slightly affected but a significant decrease in the immunological properties of the peptides produced during digestion was observed. Overall, although further studies are needed, the interaction between polyphenols and gluten proteins clearly influences gluten protein digestion and immunogenicity, thus suggesting that the consumption of dietary polyphenols can significantly affect the degree of celiac disease downstream immune reactions.

An In-Vitro Study on the Role of Phosphoric Acid Presence in Carbonated Drink Influencing Proteolysis

Background Phosphoric acid is commonly used in the industry based synthetic beverages to enhance tangy taste in coke drink. The WHO and Food and agriculture organization of the United Nations have not established a recommended concentration for such drinks. Consumption of phosphorus additive containing diets like meat cheese and carbonated drinks causes various adverse health risks and also the chronic use of acidulant increases the risk of acquiring non-communicable diseases NCDs. Objective To determine the effect of phosphoric acid content of carbonated drinks on enzyme mediated proteolysis.Methods An in-vitro study involving the dephosphorylated casein substrate subjected to proteolysis by treating with trypsin in presence of carbonated beverage medium containing phosphoric acid was conducted. The proteolytic activity was determined by comparing with standard proteolysis medium and the resulting peptides were estimated by Lowryrsquos method. Results The inorganic phosphate content of two samples of carbonated coke was 35 mgdL and 27.5 mgdL respectively. The findings of the study have shown significant difference among normal digestive power of trypsin between standard proteolysis medium and under the influence of phosphoric acid containing carbonated coke beverage medium.Conclusion We conclude that this study has provided the information that phosphoric acid containing carbonated drink has an effect on trypsin enzyme activity which facilitates the higher rate of proteolysis.