Peptic Digestion Research Articles

Differential binding of gallic acid and epigallocatechin gallate to whey protein affects the interfacial adsorption and gastric digestion of O/W emulsion

Whey protein isolate (WPI) was reacted with 20, 120, and 240 μmol/g gallic acid (GA) or epigallocatechin gallate (EGCG) at 21 °C. Equilibrium dialysis testing indicated a stronger binding capacity of whey proteins with EGCG compared to GA. Both phenolics, especially EGCG, tended to reduce the adsorption of WPI at the oil–water interface and decreased the elasticity modulus (Ed) of the interfacial film. Yet, binding with 20 μmol/g of EGCG and GA (less so) resulted in significantly improved emulsifying activity of WPI, but the emulsion stability was decreased at all phenolic concentrations (except at 240 μmol/g). There was an overall improvement of pepsinolysis of both α-lactalbumin and β-lactoglobulin. In comparison with GA, EGCG yielded more pronounced effects on WPI interfacial adsorption, dilatational rheology, and peptic digestion.

Real-time monitoring of peptic and tryptic digestions of immunoglobulin G and the impact of dietary hydrocolloids on digestion

Immunoglobulin G (IgG) exhibits potent antiviral, antibacterial, and immunological activities. The digestion process and bioavailability of IgG are often a concern. Dietary hydrocolloids are crucial for regulating healthy digestion and the bioavailability of protein as functional components. Understanding the effects of dietary hydrocolloids on the digestive kinetics of IgG is requisite. Herein, the pepsin and trypsin digestion of IgG was investigated using ordered porous layer interferometry (OPLI). The real-time variation in the interference spectral shift reflected by OPLI can be converted into changes in the optical thickness (OT) to obtain a degradation kinetics curve. The impact of dietary hydrocolloids, including alginic acid sodium salt (ALG), polydextrose (PD), and konjac glucomannan (KG), on IgG degradation was evaluated using OPLI. The results demonstrated that ALG significantly inhibited the degradation of IgG by pepsin under acidic conditions, whereas the addition of PD increased the Michaelis–Menten constant for IgG degradation by trypsin. Notably, this dependence is not based on the hydrocolloid viscosity, but relies more on the electrical properties. The study enhances our understanding of how hydrocolloids affect IgG digestion and could provide valuable insights into preserving IgG activity and facilitating the development of oral drugs or health products related to IgG.

Lectin from edible seaweed Meristotheca papulosa exhibits a high digestion-resistant property

The physiological impacts of polysaccharides and lipids in seaweed on human health are becoming clearer, but the behavior of the protein components, especially lectins, after ingestion remains poorly understood. In this study, we examined the resistance of edible red algae-derived lectins to digestive enzymes. We found that a lectin extracted from Meristotheca papulosa (MPL-1), belonging to the Jacalin-related lectin family, was relatively stable when subjected to both peptic and tryptic digestion and retained its hemagglutination activity after 24 h of digestion. The activity of MPL-1 was also maintained without a large change for 24 h following exposure to enzymes such as papain, Actinase E, and proteinase K, suggesting that MPL-1 possesses a strong resistant property against proteolytic digestion. We examined the anti-proliferation activity of the MPL fraction from the algal body against HT-29, a human colon cancer-derived cell line, and found that it showed a strong inhibitory activity with a half-maximal inhibitory concentration of 4.5 μg/mL. This activity was nullified in the presence of yeast mannan, an inhibitory sugar compound of lectin, demonstrating that MPL expressed its activity through binding to the glycan moieties on HT-29. This study indicates that this proteinase-resistant lectin could play a vital role after ingestion and is expected to have an inhibitory effect against colorectal cancer.

In-Membrane Enrichment and Peptic Digestion to Facilitate Analysis of Monoclonal Antibody Glycosylation.

The number of therapeutic monoclonal antibodies (mAbs) is growing rapidly due to their widespread use for treating various diseases and health conditions. Assessing the glycosylation profile of mAbs during production is essential to ensuring their safety and efficacy. This research aims to rapidly isolate and digest mAbs for liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification of glycans and monitoring of glycosylation patterns, potentially during manufacturing. Immobilization of an Fc region-specific ligand, oFc20, in a porous membrane enables the enrichment of mAbs from cell culture supernatant and efficient elution with an acidic solution. Subsequent digestion of the mAb eluate occurred in a pepsin-modified membrane within 5 min. The procedure does not require alkylation and desalting, greatly shortening the sample preparation time. Subsequent LC-MS/MS analysis identified 11 major mAb N-glycan proteoforms and assessed the relative peak areas of the glycosylated peptides. This approach is suitable for the glycosylation profiling of various human IgG mAbs, including biosimilars and different IgG subclasses. The total time required for this workflow is less than 2 h, whereas the conventional enzymatic release and labeling of glycans can take much longer. Thus, the integrated membranes are suitable for facilitating the analysis of mAb glycosylation patterns.

Preparation and Immunochemical Characterization of a Water-Soluble Gluten Peptide Fraction for Improving the Diagnosis of Celiac Disease.

The diagnosis of celiac disease (CD) is complex and requires a multi-step procedure (symptoms, serology, duodenal biopsy, effect of a gluten-free diet, and optional genetic). The aim of the study was to contribute to the improvement of CD diagnosis by preparing a water-soluble gluten peptide fraction (called Solgluten) and by selecting gluten-specific enzyme-linked immunosorbent assays (ELISA) for the detection of gluten immunogenic gluten peptides (GIPs) in urine and blood serum spiked with Solgluten. Food-grade Solgluten was prepared by the extraction of a peptic digest of vital gluten with water, centrifugation, and freeze-drying. The process was relatively easy, repeatable, and cheap. The content of gliadin-derived GIPs was 491 mg/g. Solgluten was used as antigenic material to compare two competitive ELISA kits (R7021 and K3012) and two sandwich ELISA kits (M2114 and R7041) in their quality regarding the quantitation of GIPs in urine and blood serum. The quality parameters were the reactivity, sensitivity, coefficients of variation and determination, and curve shape. The evaluation of the kits showed a number of discrepancies in individual quality parameters measured in urine and serum. Due to the lowest limit of quantitation and the highest coefficient of determination, M2114 may be the first choice, while R7021 appeared to be less suitable because of the high coefficients of variation and unfavorable curve progression. The results set the stage for improving CD diagnosis by supplementing conventional blood tests with oral provocation with Solgluten and subsequent ELISA measurement of GIPs that could support the no-biopsy approach and by better assessing the effect of a gluten-free diet by monitoring adherence to the diet by measuring GIPs in urine and blood.

Preparation of Decellularized Tissue as Dual Cell Carrier Systems: A Step Towards Facilitating Re-epithelization and Cell Encapsulation for Tracheal Reconstruction.

Surgical treatment of tracheal diseases, trauma, and congenital stenosis has shown success through tracheal reconstruction coupled with palliative care. However, challenges in surgical-based tracheal repairs have prompted the exploration of alternative approaches for tracheal replacement. Tissue-based treatments, involving the cultivation of patient cells on a network of extracellular matrix (ECM) from donor tissue, hold promise for restoring tracheal structure and function without eliciting an immune reaction. In this study, we utilized decellularized canine tracheas as tissue models to develop two types of cell carriers: a decellularized scaffold and a hydrogel. Our hypothesis posits that both carriers, containing essential biochemical niches provided by ECM components, facilitate cell attachment without inducing cytotoxicity. Canine tracheas underwent vacuum-assisted decellularization (VAD), and the ECM-rich hydrogel was prepared through peptic digestion of the decellularized trachea. The decellularized canine trachea exhibited a significant reduction in DNA content and major histocompatibility complex class II, while preserving crucial ECM components such as collagen, glycosaminoglycan, laminin, and fibronectin. Scanning electron microscope and fluorescent microscope images revealed a fibrous ECM network on the luminal side of the cell-free trachea, supporting epithelial cell attachment. Moreover, the ECM-rich hydrogel exhibited excellent viability for human mesenchymal stem cells encapsulated for 3 days, indicating the potential of cell-laden hydrogel in promoting the development of cartilage rings of the trachea. This study underscores the versatility of the trachea in producing two distinct cell carriers-decellularized scaffold and hydrogel-both containing the native biochemical niche essential for tracheal tissue engineering applications.

Protostrongylus caprae Zdzitowiecki et Boev, 1971 (Nematoda: Protostrongylidae) – First record in Alpine ibex (Capra ibex Linnaeus, 1758) from Europe

In the course of a survey of the endoparasites of Alpine ibex (Capra ibex) from Austria, examination of the lungs revealed male Protostrongylus nematodes presenting morphological characters which differed from those of the three Protostrongylus species previously reported from this host. Fragments of 16 adult male and 4 adult female nematodes extracted from the lung tissue of two female ibex following peptic digestion were subjected to close microscopic examination. Based on their morphology, the lungworms were identified as Protostrongylus caprae Zdzitowiecki et Boev, 1971. This species was originally described from Siberian ibex (Capra sibirica) in Asia and previously only reported from this host from Kazakhstan and Mongolia. The identification of P. caprae in Alpine ibex represents a new host and geographical record and reinforces the interest to further study the parasite diversity of wild ungulates for a better understanding of complex host-parasite associations and biogeography.

Macroscopic and Microscopic Survey of Sarcocystis spp. Infection in Slaughtered Cattle and Sheep in Tabriz, Iran

Background & Aims: Sarcocystis infection is one of the most common protozoan infections between humans and animals, which is caused by different species of Sarcocystis. The study aimed to investigate Sarcocystis infection in cattle and sheep slaughtered in Tabriz slaughterhouse by microscopic and macroscopic methods. Materials amd Methods: Diaphragmatic muscles of 500 cattle and 800 sheep were randomly selected for macroscopic and microscopic Sarcocystis cysts. A naked eye examination was done for macroscopic sarcocysts, while peptic digestion and Daub smear method were used for the microscopic cysts. Results: The overall prevalence of Sarcocystis spp. infection was 44.0% and 68.25% in cattle and sheep, respectively. The results showed that rate of infection of cattle with Sarcocystis spp. was 10.4%, 90.0%, and 22.3% by macroscopic, peptic digestion, and Daub smear methods, respectively. Meanwhile, the percentage of infected sheep was determined by macroscopic, peptic digestion, and Daub smear methods as 30.6%, 100.0%, and 44.1%, respectively (P<0.05). Conclusion: It is concluded that digestion is a perfect method for diagnosing sarcocysts in cattle and sheep. As well as, the high prevalence of microscopic Sarcocystis spp. in cattle and sheep of Tabriz, is suggested that meat should be cooked sufficiently, the people to be trained not to feed their dogs and cats with uncooked meat.

Immobilization of silver ions onto casein

In this study, the physicochemical and biological properties of silver-casein complexes were investigated. The casein modification was carried out by a novel method, i.e., at basic conditions (pH 8) using silver precursor in a form of ammonia complex [Ag(NH3)2]+. The selected experimental conditions allowed us to obtain high colloidal stability of protein suspension and also minimized the risk of metal secondary reduction. Subsequently, the mechanism of silver immobilization was evaluated by using a batch sorption study (Freundlich, Langmuir isotherm modeling). Moreover, the influence of accompanying the protein ions on the silver binding process was studied (using ultrafiltration). Results revealed, that casein after the desalting step has much higher silver-binding capacity (258.2 mg/g) compared to untreated protein (157.1 mg/g). The nature of casein-silver interactions was comprehensively studied by multiple instrumental techniques, namely, spectrometric (ICP-MS), spectroscopic (DLS, ATR-FTIR, Fluorescence Spectroscopy), electron microscopy (STEM, SEM-EDX), and separation (SDS-PAGE). Results indicated, that silver sorption had a complex character. The heterogeneous character of metal binding processes was discovered. The DLS studies pointed out the great role of phosphoserine residues in silver-casein interactions and underlined their impact on the micelle size and structure. Moreover, STEM images confirmed the growth of silver nanoparticles upon metal binding to casein. According to FTIR analysis, carboxylic groups of aspartic and glutamic acid were identified as potential metal-binding sites which also could participate in silver reduction. Peptic digestion studies showed a relevant influence of silver incorporation on the structural stability of caseins. Finally, the biological activity of the 600Ag-CN complex was evaluated. Results indicated that the complex effectively inhibited the growth of both Gram-positive (S. aureus) and Gram-negative (K. pneumoniae) bacteria. Still, the treatment of mouse fibroblast cell line L929 with analyzed complex (0.32 mg/mL of 600Ag-CN corresponding to 7.5 µg/mL of silver) decrease cell viability up to 60 %. The toxic activity of the complex may be connected to the Ag+ release. The silver desorption study showed that 600Ag-CN complex released 21.5 %, 49.3 %, and 68.7 % in pH 6.8, 4.5, and 1.2 respectively.

Advanced Studies on Toxoplasma in Buffalo Meat

Since buffalo meat, has been demonstrated to be a potential source of human infection, a careful evaluation of the prevalence of Toxoplasma infection in this meat is needed. Tissue cysts of Toxoplasma gondii are frequently found in the skeletal muscles of buffaloes. This study evaluated the prevalence of Toxoplasma gondii in the meat juice of buffalo meat samples via several diagnostic techniques to protect public health. Peptic digestion, histopathology, and serology were performed on meat juice from 100 buffalo meat samples from local butchers and retail beef markets. Eighteen samples (18%) were suspected of the presence of bradyzoites after digestion, and were subjected to histopathology which illustrated that only six samples (6%) were suspected to be Toxoplasma tissue cysts. After that periodic acid Schiff (PAS) stain confirmed that only three samples (3%) were Toxoplasma. Finally, enzyme-linked immunosorbent assay (ELISA) asserted that those three samples were Toxoplasma gondii. This study provides significant evidence about risk of human exposure to Toxoplasma through the consumption of raw or undercooked buffalo meat potentially contaminated with infectious tissue cysts.

Potential Effect of Medicinal Plants on the Prevention of Gastric Ulcer: Mechanism of Actions

Medicinal plants have been widely studied to identify plant-based anti-gastric ulcer medicines. The mechanism of gastroprotective action is important to discover the potential lead compounds for drug development. All relevant articles between 2011 and 2021 focusing on Malaysian plants were collected and analyzed to understand the underlying pathways. Keywords include peptic ulcer, gastric ulcer, NSAIDs (Non-Steroidal Anti-Inflammatory Drugs), Helicobacterpylori, medicinal plant, gastroprotection, antiulcer, acid secretion, cytoprotective, and digestion processes were applied in the search engines. Twenty-two of the plants had been reported based on the collected data. The review concludes that Malaysian plants could protect the gastric wall against necrotizing agents like ethanol and NSAIDs. This is mainly due to four critical defensive mechanisms: cytoprotective barriers, regulation of heat-shock protein 70 (HSP70) and pro-apoptotic protein (BAX), gastric acid secretion, and antioxidant capability. The mechanisms have been illustrated in the schematic diagrams for better understanding.

Zero-Degree Celsius Capillary Electrophoresis Electrospray Ionization for Hydrogen Exchange Mass Spectrometry

Currently, fast liquid chromatographic separations at low temperatures are exclusively used for the separation of peptides generated in hydrogen deuterium exchange (HDX) workflows. However, it has been suggested that capillary electrophoresis may be a better option for use with HDX. We performed in solution HDX on peptides and bovine hemoglobin (Hb) followed by quenching, pepsin digestion, and cold capillary electrophoretic separation coupled with mass spectrometry (MS) detection for benchmarking a laboratory-built HDX-MS platform. We found that capillaries with a neutral coating to eliminate electroosmotic flow and adsorptive processes provided fast separations with upper limit peak capacities surpassing 170. In contrast, uncoated capillaries achieved 30% higher deuterium retention for an angiotensin II peptide standard owing to faster separations but with only half the peak capacity of coated capillaries. Data obtained using two different separation conditions on peptic digests of Hb showed strong agreement of the relative deuterium uptake between methods. Processed data for denatured versus native Hb after deuterium labeling for the longest timepoint in this study (50,000 s) also showed agreement with subunit interaction sites determined by crystallographic methods. All proteomic data are available under DOI: 10.6019/PXD034245.

Fibrillation of human insulin B-chain by pulsed hydrogen-deuterium exchange mass spectrometry

Insulin forms amyloid fibrils under slightly destabilizing conditions, and B-chain residues are thought to play an important role in insulin fibrillation. Here, pulsed hydrogen-deuterium exchange mass spectrometry (HDX-MS), far-UV circular dichroism spectroscopy, thioflavin T (ThioT) fluorescence, turbidity, and soluble fraction measurements were used to monitor the kinetics and mechanisms of fibrillation of human insulin B-chain (INSB) in acidic solution (1 mg/mL, pH 4.5) under stressed conditions (40°C, continuous shaking). Initially, INSB rapidly formed β-sheet-rich oligomers that were protected from HD exchange and showed weak ThioT binding. Subsequent fibril growth and maturation was accompanied by even greater protection from HD exchange and stronger ThioT binding. With peptic digestion of deuterated INSB, HDX-MS suggested early involvement of the N-terminal (1–11, 1–15) and central (12–15, 16–25) fragments in fibril-forming interactions, whereas the C-terminal fragment (25–30) showed limited involvement. The results provide mechanistic understanding of the intermolecular interactions and structural changes during INSB fibrillation under stressed conditions and demonstrate the application of pulsed HDX-MS to probe peptide fibrillation.

Molecular Identification of Sarcocystis Species in Sheep from Lithuania.

Simple SummaryMembers of the genus Sarcocystis (Apicomplexa: Sarcocystidae) are protozoans that have a two-host, prey–predator life cycle. These parasites are most thoroughly examined in economically important animals. Several Sarcocystis species are known to form macroscopic and microscopic sarcocysts in the muscle tissues of sheep. A previous study carried out in Lithuania has shown a maximum Sarcocystis infection prevalence in sheep and a high parasite burden; however, species were not identified. In the present study, diaphragm, oesophagus, and heart samples of 69 sheep raised in Lithuania were examined. No macrocysts were detected in the sheep muscles, while the microcysts found corresponded to two morphological types. By molecular methods, two Sarcocystis species, S. arieticanis and S. tenella, using canids as their definitive hosts, were identified for the first time in sheep from Lithuania. Both species were detected in all the studied animals. In summary, very high detection rates of S. arieticanis and S. tenella ranging from 82.61% to 100% were established in the examined diaphragm, oesophagus, and heart muscle samples of sheep.Data on the distribution of different Sarcocystis species in various muscles of sheep are scarce. In the present study, 190 diaphragm, oesophagus, and heart muscle samples of 69 sheep raised in Lithuania were examined for the presence of Sarcocystis spp. Under a light microscope, two morphological types of microcysts corresponding to S. arieticanis and S. tenella were detected. Eight and 12 sarcocysts of S. arieticanis and S. tenella, respectively, were isolated and characterised by the sequencing of a portion of cox1. The sequence comparisons revealed the highest similarity between European and Asian isolates of S. arieticanis and S. tenella obtained from domestic sheep and other wild Caprinae hosts. Based on peptic digestion, nested PCR targeting cox1, and sequencing, a 100% infection prevalence of S. arieticanis and S. tenella was observed in the 69 studied animals. The occurrence of S. tenella was significantly higher in the diaphragm than in the oesophagus (χ2 = 13.14, p < 0.001), whereas differences in the prevalence of S. arieticanis in the studied muscle types were insignificant (χ2 = 1.28, p > 0.05). Further molecularly based epidemiological studies are needed to compare the prevalence of Sarcocystis species in various muscles of sheep raised in different geographic regions.

Developmental stages of the ballan wrasse from first feeding through metamorphosis: Cranial ossification and the digestive system.

We have described six developmental stages for the ballan wrasse, from the first feeding until the juvenile stage, supported by specific descriptions of cranial ossification, maturation of the digestive tract, and growth‐correlated stages. The initial formation and development of bones are closely linked to the functional anatomical structures required for the mechanics of its feeding behavior and ingestion, particularly the jaws and branchial regions involved in opening the mouth and capturing food particles. The overall ontogeny of the cranial structure compares to that of other teleosts. The cranial ossification of the ballan wrasse skull and the development of its dentary apparatus—first pharyngal teeth and later oral teeth—is linked to the development of the digestive system and to their feeding habits, from preying on zooplankton to feeding on crustaceans and invertebrates on rocks and other substrates. As ballan wrasse is a nibbler, eating small meals, the digestive tract is short compared to the length of the fish; there is no stomach or peptic digestion and also no distinctive bulbus and pyloric ceca. The liver and exocrine pancreas and their outlets terminating in the lumen of the most anterior part of the intestine are important in the digestive process and develop with a larger volume than that in gastric teleosts, relative to the digestive system.

A multi-tasking stomach: functional coexistence of acid-peptic digestion and defensive body inflation in three distantly related vertebrate lineages.

Puffer and porcupine fishes (families Diodontidae and Tetraodontidae, order Tetradontiformes) are known for their extraordinary ability to triple their body size by swallowing and retaining large amounts of seawater in their accommodating stomachs. This inflation mechanism provides a defence to predation; however, it is associated with the secondary loss of the stomach's digestive function. Ingestion of alkaline seawater during inflation would make acidification inefficient (a potential driver for the loss of gastric digestion), paralleled by the loss of acid-peptic genes. We tested the hypothesis of stomach inflation as a driver for the convergent evolution of stomach loss by investigating the gastric phenotype and genotype of four distantly related stomach inflating gnathostomes: sargassum fish, swellshark, bearded goby and the pygmy leatherjacket. Strikingly, unlike in the puffer/porcupine fishes, we found no evidence for the loss of stomach function in sargassum fish, swellshark and bearded goby. Only the pygmy leatherjacket (Monochanthidae, Tetraodontiformes) lacked the gastric phenotype and genotype. In conclusion, ingestion of seawater for inflation, associated with loss of gastric acid secretion, is restricted to the Tetraodontiformes and is not a selective pressure for gastric loss in other reported gastric inflating fishes.

Sarcocystis cruzi in Egyptian slaughtered cattle (Bos taurus): epidemiology, morphology and molecular description of the findings.

Sarcocystis spp. are one of the most common foodborne tissue cyst-forming coccidia with a public health and veterinary concern. The existing study aimed to rectify the epidemiological profile of Sarcocystis spp. infection in the cattle carcasses as well as to explore the structure and phylogenetic features of Sarcocystis spp. isolates. A total of 292 cattle carcasses were checked for the existence of sarcocysts using light microscopy (LM) via muscle squash (MS) and peptic digestion (PD) analysis from January 2020 to December 2020. Individual sarcocysts from different cattle tissues were selected for morphologic characterization and DNA extraction. Each sarcocyst's 18S rDNA gene was amplified, sequenced, and analyzed. Overall, 92.5% (270/292) of cattle tissue samples contained microscopic thin walled sarcocysts and were exclusively found in esophagus by light microscopy. A statistically insignificant relationship exists between the prevalence of infection and age groups, gender of cattle, and the seasonal dynamics (P>0.05). Sarcocysts ultrastructural features were completely discussed. Sequencing of 18S rDNA Sarcocystis gene confirmed S. cruzi (identity 99-100%), which was the first molecular identification of the current isolate in the study region. The current survey initially provides a brief account of knowledge about the epidemiology of Sarcocystis spp. infecting cattle and it is considered a starting point for the development of health awareness and efficient preventive schemes for this zoonotic protozoan parasite.

STUDY IN THE EPIDEMIOLOGY OF SARCOCYSTOSIS SARCOCYSTIS CAMELI IN CAMELS IN AI-QADISIYAH PROVINCE

The aim of study was to investigate the prevalence of macroscopic and microscopic sarcocystosis of 312 camels slaughtered in Al-Qadisiyah province abattoirs. The developmental stages were studied in experimentally infected dogs with Sarcocystis cameli. For macroscopic sarcocystis naked eye examination was done while for microscopic type, the methods were employed (peptic muscular digestion, trichinoscopy, squeezing and histological examination) for the detection of infection in esophagus, heart, diaphragm and skeletal muscles. The percentage prevalence of macroscopic cysts were first recorded (0.64%) among the different organs examined. The rate of microscopic infection was (83.3%) in peptic digestion method followed by squeezing and trichinoscopy were 78.47 % and 58% respectively The highest rate of infection was recorded in the esophagus and the lowest in the heart. Histological examination revealed two different morphological cysts, the first one with thin wall and the other thick striated wall. The pre patent periods were 8-9 and 10-12day respectively, each infected dog-shed total about 32 * 10* sporocysts per gram of faeces. The peak of shedding reached 326*10* sarocystis per gram of faeces day12 post infection histological development stages of the parasite were detected in the small intestine mucosa of dog in days 6 and 12 post infection.

Aggregability and digestibility study of fruit juice fortified camel milk powder proteins

In this work, we observed the effect of grape juice (% concentrated juice/% concentrated camel milk: GJ20/80, GJ50/50) and pomegranate juice (PJ20/80, PJ40/60) fortification on camel milk (CM) protein solubility and digestibility. Proteins were dissolved in sodium phosphate buffer to 50 mg/ml and defatted prior Bradford assay of protein concentration, then analyzed by Size Exclusion-Ultra High-Performance Liquid chromatography (SE-UHPLC). The CM protein aggregation and their stability were further monitored at different pH 2.0, 4.0, and 7.5 via sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Freeze dried CM (FDCM) was the reference sample and our results showed that GJ50/50 and PJ40/60 with the highest fruit juice ratio had the lowest protein content in the supernatant, hence the decreased solubility. SE-UHPLC of supernatants showed a slight decrease in retention times of 11 kDa and 62 kDa proteins for GJ50/50 and PJ40/60 suggesting a possibility of adduct formation due to fortification leading to higher molecular weight. The simulated static in vitro gastrointestinal digestion of samples revealed that most soluble proteins were readily digested by pepsin, trypsin and chymotrypsin enzymes leading to small peptides. However, the SDS PAGE of pellets showed the partial resistance of casein and α-lactalbumin against peptic digestion.

Development of novel blue emissive carbon dots for sensitive detection of dual metal ions and their potential applications in bioimaging and chelation therapy

In recent years, there has been an increased interest in the use of fluorescent carbon dots (C-dots) as an alternative to toxic synthetic organic dyes in live cell imaging, medical diagnostics and other diverse biomedical applications. In the present work, highly fluorescent C-dots have been prepared from commercially available peptic digest of animal tissue, without using any additional chemical reagent for surface functionalization. The synthesized C-dots are monodispersed nanomaterials with hydroxyl, carboxyl and amino surface functionalities and remain stable in high ionic strength media and over a wide range of pH. They exhibit a strong blue fluorescence upon excitation at 350 nm with a high quantum yield of 61%. The potential use of these C-dots as fluorescent nanoprobe for specific metal ions (Cu2+ and Hg2+) detection through chelation, radical scavenging and cellular imaging has been investigated. These highly fluorescent labels show rapid cellular internalization without hampering cellular integrity. Cell proliferation assay demonstrates that these C-dots have minimal cell toxicity even at a high concentration of 3 mg/mL. They show significant quenching on incubation with cells pretreated with Cu2+ and Hg2+ ions. They also show rapid exocytosis from cells showcasing their high potential for chelation therapy. Thus, this study offers a scalable synthesis approach for highly fluorescent and bio-compatible C-dots from a cost-effective precursor, which can be used for specific metal ions detection and their removal from cells through chelation via exocytosis. They can also be used as an alternate to synthetic organic dyes for fluorescence-based cell-imaging.