Search Results (201)

The study presents the potential of milkfish frame, a by-product of milkfish processing, as a source of dipeptidyl peptidase IV (DPP-IV) inhibitory and antioxidant peptides with potential applications in type 2 diabetes management. Proteomic analysis identified key proteins, including 65 kDa warm temperature acclimation protein 1 and myosin heavy chain. In silico prediction (BIOPEP-UWM) guided the selection of proteases for generating DPP-IV inhibitory peptides. Enzymatic hydrolysates were produced and evaluated for bioactivity. Among the treatments, pepsin hydrolysis (2% v/v, 8 h) yielded the highest peptide content (283.64 mg/g), soluble protein (86.46%), and DPP-IV inhibitory activity (68.47%). The resulting milkfish frame pepsin hydrolysate (MFH) was further enhanced through ultrafiltration and simulated gastrointestinal digestion, which improved the DPP-IV inhibitory and antioxidant capacities. Cytotoxicity assays confirmed that MFH (0–100 μg/mL) was non-toxic to FL83B hepatocytes after 24 h. Moreover, treating TNF-α-induced FL83B cells with 10 μg/mL MFHs improved cell viability, reducing the toxicity induced by TNF-α in cells. These findings show that MFHs exhibit promising antidiabetic potential and could serve as natural alternatives to synthetic drugs for type 2 diabetes management. This also demonstrates the valorization of fish processing by-products into functional food ingredients, advancing sustainable approaches in food innovation. Full article

The tree bean (Parkia timoriana), an underutilized legume valued for its nutritional profile, represents a potential source of bioactive peptides for diabetes management. To our knowledge, this is the first study to identify and characterize DPP-IV inhibitory peptides derived from tree bean seed protein hydrolysates. The tree bean proteins were digested with trypsin, thermolysin, chymotrypsin, pepsin, and simulated gastrointestinal (SGI) enzymes, among which SGI hydrolysis yielded the highest degree of hydrolysis (14%) and strongest DPP-IV inhibitory activity (IC₅₀ = 1289 ± 58 µg/mL). Guided by DPP-IV inhibitory assays, sequential fractionation using strong cation exchange and RP-HPLC yielded the most potent fraction, H5, with an IC₅₀ of 949 ± 50 µg/mL. After peptide identification and synthesis, APLGPF (AF6) emerged as the most potent inhibitor, with an IC₅₀ of 396 ± 18 µM. Enzyme kinetics revealed a non-competitive inhibition mechanism, corroborated by molecular docking, which indicated binding at an allosteric site of DPP-IV. Furthermore, AF6 remained stable under simulated gastrointestinal digestion and enzymatic exposure, highlighting its resistance to proteolysis. Taken together, these findings highlight P. timoriana as an underexplored source of peptides with DPP-IV inhibitory activity and identify AF6 as a promising lead for developing functional foods or nutraceuticals aimed at type 2 diabetes management. Full article

There is increasing interest in the health-promoting potential of plant protein-derived peptides for managing metabolic disorders. This study investigated the impact of pepsin digestion on pre-hydrolysed versus non-hydrolysed pea protein. Pepsin digestion resulted in a higher degree of hydrolysis in pre-hydrolysed samples (64%) compared to the non-hydrolysed samples (~40%). The pepsin hydrolysates from the pre-hydrolysed protein showed stronger inhibition of key metabolic enzymes compared to non-hydrolysed samples. After ultrafiltration to enrich peptides <10 kDa, inhibition of α-amylase, α-glucosidase, and ACE was markedly enhanced, achieving a maximum of 44.5%, 54% and 95%, respectively. Peptidomic analysis identified unique peptide sequences in the ultrafiltered pre-hydrolysed fraction, in silico prediction confirmed their bioactive potential. These findings demonstrate enhanced bioactivity in pre-hydrolysed pea protein samples following pepsin hydrolysis, which was most evident in the ultrafiltrated fractions. Overall, this approach highlights the relevance of enzymatic hydrolysis and peptide enrichment strategies in developing functional ingredients to support glucose regulation and cardiovascular health. Full article

The tropical gar (Atractosteus tropicus Gill, 1863) is a prehistoric fish of high nutritional value in southern Mexico and Central America. However, some aspects related to the effects caused by alternative protein sources, such as insect meal, as a substitute for fish meal on the growth and expression of digestive enzyme genes, are still unknown. A total of 225 juveniles of A. tropicus were used and fed five experimental diets, each in triplicate, with different levels of substitution of fishmeal (FM) protein with house cricket meal (HCM) protein. A control diet that contained no HCM (T1-0% HCM) was used, and substitutions ranged from 25 to 100% of FM protein by HCM (T2-25% HCM, T3-50% HCM, T4-75% HCM, and T5-100% HCM) for 45 days. The results of this study indicate that T4-75% HCM showed the best growth indices, such as feed efficiency (EF), feed conversion ratio (FCR), specific growth rate (SGR), as well as higher gene expression of pepsin and trypsin, while chymotrypsin showed higher expression in T3. The higher performance achieved in T4-75% HCM may be due to the fact that, in the early stages, insects are part of the natural diet of A. tropicus. The inclusion of cricket meal as a partial substitute for fish meal is not recommended in quantities greater than T4-75%. Full article

Thanks to its tolerance to drought, sorghum is a cereal crop that is extensively cultivated in the sub-Saharan region. Its good nutritional value makes it an interesting raw material for the food industry, although several anti-nutritional features pose a challenge to exploiting its full potential. In this study, we evaluated whether the process of germination may represent a way of improving the macro- and micro-molecular profile of sorghum, lowering the content of anti-nutritional factors, and promoting the synthesis of bioactive compounds. Germination for 48 and especially 72 h promoted the hydrolysis of starch and proteins, enhanced antioxidant activity, increased the content of polyphenols, mainly flavonols and flavanones, and promoted the conversion of γ- to α-isomers of tocopherols. At the same time, it significantly reduced the concentration of phytates and linoleic acid, enhancing pepsin activity and contributing to the inaugural examination of the impact of sprouted sorghum on digestive protease activity. These findings could help to promote the utilization of sprouted sorghum as a premium ingredient for food products, providing significant nutritional advantages. Full article

Although the pancreas is the organ that produces the most critical digestive enzymes, there are other important contributors to the cleavage of food into absorbable units. Pre-pancreatic digestion of carbohydrates occurs through the action of salivary amylase. Pre-pancreatic digestion of fats is mediated by lingual and gastric lipases, and their action may be important as a signal for coordinated digestion. Pepsin, which is present in the stomach, initiates the digestion of dietary proteins into peptides and amplifies distal proteolysis. The major post-pancreatic intestinal carbohydrate-digesting enzymes are sucrase-isomaltase, maltase-glucoamylase and lactase-phlorizin hydrolase. There are no post-pancreatic mucosal enzymes that act on dietary triglycerides; however, the complete digestion of phospholipids depends on several brush border phospholipases. Intestinal processing is an important contributor to digestion of proteins, although mucosal proteases may serve as signaling proteins rather than as primary adjuncts to dietary protein digestion and absorption. This review describes the role of these non-pancreatic digestive enzymes in supporting nutritional health. Full article

Using wheat flour milling (WFM) co-products in pig diets may reduce feed cost. Still, energy digestibility is lower for WFM co-products than for feed grains. Inadequate information exists about their fermentation characteristics and the relationship between digestible energy (DE) value and chemical characteristics or in vitro energy digestibility. The objectives were to (1) determine the chemical characteristics, in vitro and in vivo DE values, and energy digestibility of WFM co-products in growing pigs; (2) determine their in vitro microbial fermentation characteristics, and (3) establish relationships between in vivo DE value of WFM co-products and their chemical composition, fermentation characteristics, or in vitro digestibility values. Across Canada, 94 WFM co-products were sampled and characterized for their chemical composition and in vitro dry matter (DM) and energy digestibility using pepsin, pancreatin, and a multi-enzyme complex containing arabinase, β-glucanase, hemicellulase, xylanase, and cellulase. The in vivo energy, DM digestibility and DE value of 9 WFM co-products (2 shorts, 5 millrun, 1 middling, and 1 bran) were determined using a corn-based diet and 40 growing pigs in two periods to obtain 8 observations per diet. After in vitro digestion, the 9 WFM co-product samples were subjected to microbial fermentation using fresh fecal inoculum in a cumulative gas-production technique. The WFM co-products had a high content of crude fiber (up to 7.9% in shorts, 9.9% in millrun, 7.1% in middlings, and 12.0% in bran) and crude protein (CP; up to 27.8% in shorts, 20.0% in millrun, 22.1% in middlings, 15.9% in bran). The DE values ranged from 2.84 to 3.74 Mcal/kg DM among WFM co-products. Among chemical characteristics, neutral detergent fiber was the best predictor (R² = 0.81) for in vivo DE value, followed by crude fiber (R² = 0.78), and acid detergent fiber (R² = 0.72). The in vitro DE values predicted (R² = 0.80) in vivo DE values of 9 WFM co-products. Based on principal component analysis, total gas and short-chain fatty acid production varied among WFM co-products and was associated with the CP content of WFM co-products. In conclusion, WFM co-products contain high crude protein and have a high DE value for growing pigs but vary substantially in nutritional value. Full article

Balantioides coli is the only ciliate currently described as an intestinal parasite of humans, although it can also infect other animals, particularly pigs. Its in vitro cultivation remains challenging, and no axenic culture system is currently available. Cultures are initiated by adding small amounts of feces containing cysts or trophozoites to the culture medium. Implantation success is lower when starting from cysts, and the mechanisms and early events of excystation remain poorly understood. In this study, we describe the sequence of events involved in excystation and identify factors potentially important for culture establishment. Cysts were obtained from orangutan feces and genetically confirmed as B. coli. Only viable cysts, determined by trypan blue or methylene blue exclusion, were used. After artificial digestion with pepsin and trypsin, cysts were incubated at 28 °C for up to 72 h in DMEM supplemented with L-glutamine, yeast extract, fetal bovine serum, and starch granules. Excystation began with a fissure in the cyst wall, allowing for bacterial entry. This appeared to stimulate the trophozoites, the increased motility of which progressively weakened and ruptured the wall, allowing for their emergence. Wall rupture and bacterial entry were critical for activation., whereas starch type had no apparent influence. Excystation occurred within the first hours; otherwise, cysts degenerated. Full article

The spread of invasive pests can exacerbate the threat of pest stress to agricultural production. Screening natural antifeedants from the secondary metabolites of plants may provide efficient alternative control methods for the integrated management of invasive pests. Therefore, in this study, the three phenolic substances were evenly mixed with the artificial diet at mass ratios of 1:200 and 1:40, respectively. The treatment groups were labeled as follows: vanillic acid (Va1: 1:200, Va2: 1:40), sinapic acid (Si1: 1:200, Si2: 1:40), and syringic acid (Sy1: 1:200, Sy2: 1:40). Subsequently, the feed intake, body weight, protein content, and digestive enzyme activity of the S. frugiperda feeding were measured. This research was extended to the pupal and adult stages, focusing on pupation rate, pupal weight, adult emergence rate, and adult longevity. The results showed that the food intake and body weight of the 4th–6th instars of S. frugiperda decreased significantly after feeding on the different ratios of phenolic substances. Although the protein accumulation of the 4th–5th-instar larvae was inhibited, the protein content of the 6th-instar larvae showed significant accumulation, with that of the Va2 and Sy1 treatment groups being 124.84% and 165.07% of that of the control, respectively. At the same time, the trypsin activity of the 4th–6th-instar larvae in different treatment groups significantly increased, while the activities of pepsin and α-amylase fluctuated but overall showed an increasing trend. The interference of vanillic acid, sinapic acid, and syringic acid on the digestion and absorption of the larvae limited the pupation rate but did not have a significant effect on the pupal weight. All three phenolic substances reduced the adult emergence rate, but unlike the sinapic acid and syringic acid treatments, vanillic acid also had a negative impact on adult longevity. These results can provide material reserves for the development of antifeedants for S. frugiperda, and can also provide optimal plans for its ecofriendly prevention and control. Full article

Aging is associated with structural and functional changes in the gastrointestinal tract; however, its impact on gastric secretion remains unclear. This scoping review examines whether gastric secretion declines with age and explores its clinical implications. Following the PRISMA guidelines, PubMed, Web of Science, Embase, and Google Scholar were systematically searched from inception to December 2024. Fifteen studies (both animal and human) met the inclusion criteria: they were written in English, directly relevant to aging and gastric secretion, and had a clearly stated methodology. Evidence strength was assessed using the GRADE framework, revealing predominantly low to moderate certainty due to small sample sizes and observational study designs. Animal studies have demonstrated reduced acid secretion in older rats, which is attributed to mucosal atrophy and diminished responsiveness to gastrin. Recent human studies suggest that aging does not directly reduce acid output, as reduced acid secretion may result from a higher prevalence of atrophic gastritis, Helicobacter pylori infection, and the widespread use of proton pump inhibitors. Antisecretory therapy may lack benefits in older adult patients with hypochlorhydria/achlorhydria and increase the risk of adverse effects. Pepsin output declines with aging due to reduced chief cell function, although its clinical impact on digestion is unclear. Since intrinsic factor secretion far exceeds the amount necessary for its physiological function, even low amounts seem to be sufficient to prevent cobalamin deficiency. Age-related decline in gastric secretion is mostly attributed to age-associated disorders; however, impairment of secretory function in older people is frequent. Future research should prioritise longitudinal studies, larger cohorts, and histology-stratified analysis. Full article

The aim of this study was to investigate the effects of sodium butyrate (SB) on growth performance, digestive ability, blood health, and ammonia tolerance of largemouth bass. During the experiment, largemouth bass were fed different diets (0.00%, 0.50% and 1.00% SB) followed by a 96-h ammonia challenge. In this study, dietary supplementation of SB can improve the growth (weight gain rate increased; GH and IGF 1 genes up-regulated) of largemouth bass. The addition of SB also significantly increased serum total protein, albumin and globulin contents and reduced triglycerides, cholesterol and aspartate transaminase contents. The digestive ability (pepsin, lipase, amylase, alkaline phosphatase, creatine kinase, gamma-glutamyltranspeptidase, sodium-potassium adenosine triphosphatase, villus height and muscular thickness increased) was significantly higher in the 0.50% and 1.00% SB groups. SB also improved the anti-inflammatory capacity (IL 1 and IL 8 genes down-regulated) of largemouth bass. The addition of SB to feed significantly reduced the cumulative mortality rate after 96 h of ammonia stress. SB significantly increased liver ammonia metabolism enzyme (arginase, argininosuccinate synthetase, ornithine transcarboxylase and argininosuccinate lyase) and inducible nitric oxide synthase activity, and significantly decreased the neuronal nitric oxide synthase activity. The results indicate that dietary supplementation of SB can promote growth and improve digestive ability, blood health, and ammonia tolerance in largemouth bass. Full article

Bovine milk protein preparations (MPPs), namely micellar casein concentrate (MCC), serum protein concentrate (SPC), and MCC with ultrafiltrated buttermilk permeate (MBP), were analyzed as sources of inhibitors of angiotensin-converting enzyme (i.e., ACE) and dipeptidylpeptidase IV (i.e., DPP-IV) as well as antioxidative peptides. The studies involved in silico predictions of the release of biopeptides from bovine milk proteins. Then, all MPPs were subjected to the simulated gastrointestinal digestion using the INFOGEST protocol. Results using a BIOPEP-UWM database tool indicated that 59 biopeptides exhibiting the above-mentioned activities could be produced upon the action of pepsin, trypsin, and chymotrypsin. Thirty-six biopeptides were identified in at least one of the three MPPs subjected to the INFOGEST protocol. MCC before simulated digestion exhibited the strongest ACE-inhibiting activity among all MPPs (IC₅₀ = 1.856 mg/mL). The weakest ACE inhibitory effect was demonstrated for MBP after duodenal digestion (i.e., MBP D; IC₅₀ = 7.627 mg/mL). The above MPP showed the strongest DPP-IV-inhibiting activity (IC₅₀ = 0.0067 mg/mL). All MPPs exhibited antioxidative activity, with the strongest ABTS^•+ (i.e., 2,2′-azino-bis(3-ethylbenzotialozline-6-sulfonic acid) radical scavenging effect shown for MBP D (IC₅₀ = 2.754 mg/mL), and the strongest DPPH^• (i.e., 2,2-diphenyl-β-picrylhydrazyl) radical scavenging activity (IC₅₀ = 1.238 mg/mL) demonstrated for SPC D. Among all MPPs, SPC D also exhibited the highest FRAP (i.e., Ferric Reducing Antioxidant Power) bioactivity (IC₅₀ = 13.720 mg/mL), whereas MBP D was the MPP with the lowest FRAP potential (IC₅₀ = 20.140 mg/mL). The present study results show the potential of all MPPs as functional additives to support health-beneficial functions of dairy products. Full article

This study is to explore the alleviating effects of glutamate on intestinal damage in cultured little yellow croaker. A total of 900 juvenile fish at a weight of 30.68 ± 0.12 g were randomly separated into six groups with three replicates each, and were fed a basic diet (protein at 44.42% and lipid at 12.48%) with additional glutamate at 0.00%, 0.40%, 0.80%, 1.2%, 1.60%, and 2.00%. Each replica group consisted of 50 fish in a breeding barrel (radius 1.0 m, height 1.5 m), and the experiment lasted for 54 days. The results showed that supplementation with 0.4–1.2% glutamate significantly improved the survival rate, which increased from 75.56% to 91.11%, reduced the feed conversion rate from 1.75 to 1.57, and increased the protein efficiency ratio from 1.55 to 1.85 (p < 0.05). In the intestines, the addition of 0.40–1.2% glutamate increased muscle thickness and villus height (p < 0.05), as well as the activities of pepsin, trypsin, α-amylase, and lipase (p < 0.05). Enzyme activity analysis indicated that the addition of 0.4–1.2% glutamate in the feed significantly enhanced the activities of serum Total Superoxide Dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GPx) antioxidant enzymes (p < 0.05). Transcriptome analysis of the 1.2% and 0% groups revealed that differentially expressed genes were enriched in glutathione synthesis, nutrient absorption and metabolism, and viral protein interaction with cytokine and cytokine receptor pathways. qPCR experiments verified that the addition of 1.2% glutamate significantly up-regulated the expression of antioxidant-related genes, including glutathione synthetase and Nrf2. In conclusion, the addition of glutamate can enhance growth performance, increase intestinal digestive capacity, activate intestinal glutathione synthesis to alleviate intestinal damage, and maintain intestinal health. Full article

Araecerus fasciculatus (De Geer, 1775) is an important stored-product pest worldwide. In this study, the development time, survival rate, oviposition, and digestive enzyme (α-amylase, cellulase, pepsin, and lipase) activities of A. fasciculatus fed on five commodities (coffee, jujube, maize, wheat, and kansui) were investigated. Our results showed that the developmental duration of A. fasciculatus from egg to adult was shortest on coffee beans (51.41 days) and longest on kansui (69.65 days). The survival rate of A. fasciculatus adults was lowest on kansui (42.22%) and highest on coffee beans (63.33%). Significant differences in fecundity were also observed, with the greatest number on coffee beans (80.78 eggs/female) and the lowest on kansui (50.43 eggs/female). Araecerus fasciculatus showed the greatest intrinsic rate of natural increase (r_m) on coffee beans (0.141), followed by jujube (0.129), maize (0.117), wheat (0.105), and kansui (0.097). The net productive rate (R₀) showed a similar trend to r_m, with values of 48.42, 42.53, 35.39, 27.53, and 21.47, respectively, on these stored products. Although no significant differences were observed in the lipase activities when A. fasciculatus was fed on different stored products, activities of α-amylase, pepsin, and cellulase were highest on coffee beans and lowest on kansui. The variation in the population development of A. fasciculatus associated with different foods may be related to its digestive enzyme performance. These results indicated that coffee beans were the most suitable host food, while kansui was the least suitable for the development of A. fasciculatus. Full article

Background: Gluten-related disorders, particularly celiac disease, are triggered in susceptible individuals by the toxic effects of gluten, the major storage protein of wheat grains. This toxicity can be reduced by wheat glutenases. Members of the papain-like cysteine protease family, which can act in the human gastrointestinal tract, are promising candidates for the enzymatic treatment of celiac disease. Methods: Two wheat proteases were selected using AlphaFold2, produced in recombinant forms, and characterized. Their glutenase potentials under acidic or slightly acidic conditions were evaluated and compared with the properties of the previously characterized wheat glutenase Triticain-α. Results: All enzymes tested, Ta-P7, Ta-V6, and Triticain-α, were able to hydrolyze the model substrate (α-gliadin-derived epitope) in the pH range of 3.6–7.5. Nevertheless, Triticain-α performs the most efficient hydrolysis of the peptide substrate under the conditions of the gastrointestinal tract, according to its kinetic characteristics. In the wheat gluten degradation experiment at pH 4.6 and 37 °C, both Ta-P7 and Triticain-α cleaved the mixture almost completely within 5 min. In addition, Triticain-α and Ta-P7 significantly reduced the levels of toxic peptides compared to both intact gluten and gluten treated with pepsin-trypsin digestion as tested by the Ridascreen Gliadin Kit. Conclusions: Novel wheat proteases under investigation possess the expected glutenase activity to varying degrees; however, Triticain-α is a primary candidate for potential use in the enzymatic therapy of gluten-related disorders. Full article