Acid Pepsin Research Articles

Acidic Pepsin Affects Laryngeal Carcinoma Cell Growth and Invasion Through Glycolysis.

The pathogenic mechanism underlying the effects of acidic pepsin in laryngeal cancer remains unclear. This study investigated whether acidic pepsin influences Glut-1 expression and glycolytic activity in laryngeal carcinoma cells and whether it plays a role in the growth and migration of these cells through glycolysis. In vitro study. A university-affiliated hospital. Laryngeal carcinoma TU 212 and TU 686 cells were treated with acidic pepsin and 2-deoxy-d-glucose (2-DG), then transfected with Glut-1 small interfering RNA (siRNA). Glucose uptake was detected by a radioimmunoassay counter, lactate secretion was detected by a lactic acid kit, and Glut-1 expression was detected by western blotting. Cell viability, migration and invasion, and clonal formation were assessed using the Cell Counting Kit-8, Transwell chamber, and clonal formation assays, respectively. Acidic pepsin significantly increased Glut-1 expression in laryngeal carcinoma cells compared with the control group (P < .01). It also significantly enhanced 18F-fluorodeoxyglucose (Cin/Cout) uptake, lactate secretion, cell viability, migration, invasion, and clonal formation in laryngeal carcinoma cells compared with the control group (P < .01). The glycolytic inhibitor 2-DG and Glut-1 siRNA significantly reversed the effects of acidic pepsin on laryngeal carcinoma cells (P < .01). Acidic pepsin enhances the growth and migration of laryngeal carcinoma cells by upregulating Glut-1, thus promoting glycolysis.

In vitro model to evaluate effect of acidic pepsin on vocal fold barrier function

The pathophysiology of laryngopharyngeal reflux (LPR) and its impact on the vocal fold is not well understood, but may involve acid damage to vocal fold barrier functions. Two different components encompass vocal fold barrier function: the mucus barrier and tight junctions. Mucus retained on epithelial microprojections protects the inside of the vocal fold by neutralizing acidic damage. Tight junctions control permeability between cells.Here we developed an in vitro experimental system to evaluate acidic injury and repair of vocal fold barrier functions. We first established an in vitro model of rat vocal fold epithelium that could survive at least one week after barrier function maturation. The model enabled repeated evaluation of the course of vocal fold repair processes. Then, an injury experiment was conducted in which vocal fold cells were exposed to a 5-min treatment with acidic pepsin that injured tight junctions and cell surface microprojections.Both of them healed within one day of injury. Comparing vocal fold cells treated with acid alone with cells treated with acidic pepsin showed that acidic pepsin had a stronger effect on intercellular permeability than acid alone, whereas pepsin had little effect on microprojections.This result suggests that the proteolytic action of pepsin has a larger effect on protein-based tight junctions than on phospholipids in microprojections. This experimental system could contribute to a better understanding of vocal fold repair processes after chemical or physical injuries, as well as voice problems due to LPR pathogenesis.

To study the Helicobacter pylori infection in peptic ulcer

Helicobacter pylori is a gram negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. Its major in the human pathogen that produces inflammation of the stomach and etiologically related to the duodenal ulcer, gastric ulcer, gastric cancer and mucosa-lymphoid tissue. It is weakens the protective mucous coating of the stomach and duodenum, thus allowing acid to get through to the sensitive lining beneath. Both the acid and the bacteria irritate the lining and cause a sore, or ulcer. Helicobacter treated with a combination of antibiotics plus a proton pump inhibitor. Peptic ulcer is characterized by discontinuation in the inner lining of the gastrointestinal tract because of the gastric acid secretion or pepsin. It extends into muscularis propria layer of the gastric epithelium. It usually occurs in the stomach and proximal duodenum. Peptic means that cause of the problem is due to the acid. It is most common causes in the peptic ulcers are infection with the bacterium and causes the long-term use of the non-steroidal anti-inflammatory drugs. Gastric ulcer occurs in the stomach. Duodenal ulcer occurs in the first part of the small intestine. The interplay of gastritis phenotype related to the bacterium colonization and resulting acid secretion.

Comparative assessment of anti-ulcer effects: Hydro-ethanolic extract from air-dried ray and disc florets vs essential oil of traditional Tagetes erecta (Asteraceae) in Swiss Albino rats

The Tagetes erecta Linn (family: Asteraceae) herb possesses medicinal and antioxidants value. The herb is traditionally used to treat various ailments, including ulcers. In order to investigate antiulcer activity of T. erecta herb, experimental study was performed between ray and disc florets extracted with 30 parts of water and 70 parts of ethanol solvents using Soxhlet apparatus and leaf's essential oil extracted in Clevenger apparatus by steam distillation method. Two doses of the hydroethanolic extract (400 and 800 mg/kg, Per os) and single dose of essential oil (10 ml/Kg, Per os) were administered for five consecutive days. Rat's pyloric ligation and aspirin (200 mg/kg, Per os) were used to induce acute and chronic gastric ulcers respectively. Antiulcer activity of both the herb's parts was compared on gastric juice parameters (pH, free acidity, total acidity) ulcer-index and ulcer percent protection. The p value of less than 0.05 was considered significant in statistical analysis. Elevation in pH, reduction in free acidity, total acidity and ulcer-index in both the ulcer models confirm that the test drug showed the ulcer-protective activity in rats. Dose-dependent effects were observed in the antiulcer activity of the hydroethanolic extract. However, the leaf's essential oil showed 94 % and 96.93 % ulcer protection in the pyloric ligation and aspirin-induced gastric ulcer models respectively. The hydroethanolic extract and the essential oil may be capable in part, regulating gastric acid secretion pathways or stimulating the cytoprotective secretion of bicarbonate, mucus and prostaglandins. Histological studies supported the observed antiulcer activity of the herb. The essential oil has more potent and significant anti-ulcer activity than hydro-ethanolic extract and respective standard drugs: ranitidine (50 mg/kg, Per os) & pantoprazole (20 mg/kg, Per os). The herb exhibits antiulcer activity, which could be due to the presence of lead phytochemicals: Quercetin-3-methyl ether, quercetin-7-methyl-ether & kaempferol flavonoids in the extract and limonene & terpinolene in leaf's essential oil and, thus, confirmed the traditional uses of T. erecta in the treatment of ulcers. The herb may cure acid pepsin disorders.

The antibacterial mechanism of the novel bacteriocin LpH25 and the synergistic preservation effect of this bacteriocin and Nisin in fresh milk

Bacteriocin, a natural preservative in the food industry, has been found to have a strong inhibitory effect on foodborne pathogens. This study focuses on the structure, stability and antibacterial mechanism of the novel bacteriocin LpH25, as well as the synergistic antibacterial effect of LpH25 in combination with Nisin on E. coli and S. aureus in milk. It was shown that the growth of L. rhamnosus LS-8 was inhibited by acidic environments and pepsin. LpH25 was an unsaturated polypeptide containing an aromatic ring and had good amphipathic. Additionally, bacteriocin LpH25 displayed remarkable thermal stability (121 °C, 30 min) and broad pH stability (pH 2.5–11), remaining stable at −80 °C for over 270 days and exhibiting insensitivity to various enzymes within 2 h. Moreover, LpH25 showed strong inhibitory activity against Escherichia coli, Staphylococcus aureus, and Cronobacter sakazakii within 5 h. Further experiments revealed that LpH25 could effectively inhibit the formation of E. coli outer membranes and flagella to exert antibacterial activity, ultimately leading to cell death. LpH25 inhibited the growth of S. aureus by repressing peptidoglycan synthesis. In addition, the number of viable bacteria in contaminated milk treated with LpH25 mixed with Nisin remained stable (6.5log10 CFU/mL) for seven days. This study provides important theoretical support for promoting the development of antibacterial agents, addressing the challenge of drug resistance of pathogenic bacteria, and extending the shelf life of milk.

Peptic Ulcer: A review

Peptic ulcers, characterized by painful sores that develop on the lining of the stomach, small intestine, or esophagus, are a prevalent gastrointestinal condition affecting millions worldwide. This abstract provides an overview of the causes, symptoms, and treatment options for peptic ulcers. Peptic ulcers primarily stem from the imbalance between aggressive factors such as gastric acid secretion, pepsin, and Helicobacter pylori infection, and defensive mechanisms like mucosal barrier integrity and blood flow. Lifestyle factors such as excessive alcohol consumption, smoking, and stress, along with the use of nonsteroidal anti-inflammatory drugs (NSAIDs), also contribute to ulcer formation. Symptoms of peptic ulcers include burning pain in the abdomen, bloating, nausea, vomiting, and unintended weight loss. However, some individuals may remain asymptomatic or experience atypical symptoms. Diagnosis typically involves a combination of medical history assessment, physical examination, and diagnostic tests such as endoscopy, barium X-ray, and H. pylori testing. Treatment aims to alleviate symptoms, promote ulcer healing, and prevent recurrence. Proton pump inhibitors (PPIs), histamine receptor antagonists (H2RAs), and antibiotics are commonly prescribed to reduce gastric acid secretion, eradicate H. pylori infection, and promote ulcer healing. Lifestyle modifications including dietary changes, stress reduction techniques, and cessation of smoking and alcohol consumption are also integral components of ulcer management. In conclusion, peptic ulcers are a common gastrointestinal disorder with multifactorial etiology. Early recognition of symptoms, accurate diagnosis, and prompt initiation of appropriate treatment are essential to prevent complications and improve patient outcomes.

Injectable Xenogeneic Dental Pulp Decellularized Extracellular Matrix Hydrogel Promotes Functional Dental Pulp Regeneration.

The present challenge in dental pulp tissue engineering scaffold materials lies in the development of tissue-specific scaffolds that are conducive to an optimal regenerative microenvironment and capable of accommodating intricate root canal systems. This study utilized porcine dental pulp to derive the decellularized extracellular matrix (dECM) via appropriate decellularization protocols. The resultant dECM was dissolved in an acid pepsin solution to form dECM hydrogels. The analysis encompassed evaluating the microstructure and rheological properties of dECM hydrogels and evaluated their biological properties, including in vitro cell viability, proliferation, migration, tube formation, odontogenic, and neurogenic differentiation. Gelatin methacrylate (GelMA) hydrogel served as the control. Subsequently, hydrogels were injected into treated dentin matrix tubes and transplanted subcutaneously into nude mice to regenerate dental pulp tissue in vivo. The results showed that dECM hydrogels exhibited exceptional injectability and responsiveness to physiological temperature. It supported the survival, odontogenic, and neurogenic differentiation of dental pulp stem cells in a 3D culture setting. Moreover, it exhibited a superior ability to promote cell migration and angiogenesis compared to GelMA hydrogel in vitro. Additionally, the dECM hydrogel demonstrated the capability to regenerate pulp-like tissue with abundant blood vessels and a fully formed odontoblast-like cell layer in vivo. These findings highlight the potential of porcine dental pulp dECM hydrogel as a specialized scaffold material for dental pulp regeneration.

Physicochemical and thermal properties of pepsin- and acid-soluble collagen isolated from the body wall of sea cucumbers (Stichopus hermanni).

The main objective of this work was to characterize the acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from the body wall of the sea cucumber scientifically called, Stichopus hermanni. For the extraction of ASC and PSC, the pre-treated sea cucumber body walls were subjected to 0.5M acetic acid and 5gL-1 pepsin, respectively. The yield of ASC (7.30%±0.30%) was found to be lower than the PSC (23.66%±0.15%), despite both ASC and PSC having similar chemical compositions except for the quantity of protein. The collagens produced from ASC and PSC show maximum peaks on ultraviolet-visible spectroscopic profiles at wavelengths of 230 and 235nm, respectively, with no significant difference in the maximum temperature (Tmax ) of the extracted ASC and PSC. The ASC's coloration was whiter than that of the PSC. As a result, the collagen obtained from the body wall of the sea cucumber showed promise for usage as a substitute for collagen derived from marine sources. PRACTICAL APPLICATION: The two most popular methods of collagen extraction were acid hydrolysis and enzymatic hydrolysis. To determine whether the extracted collagen is a suitable substitute for animal collagen in different industries, it is required to characterize its physicochemical qualities. This study discovered a new application for marine collagen in the food industry: The sea cucumber has collagen with a greater yield in pepsin extraction with good physicochemical qualities.

Reutilization of Pelodiscus sinensis (Chinese Soft-Shelled Turtle) Visceral Waste for cosmeceutical Applications

Pelodiscus sinensis, commonly known as the Chinese soft-shelled turtle, possesses abundant collagen, proteins, and amino acids in its shell and muscle. Pelodiscus sinensis has been historically utilized as a valuable traditional Chinese medicine. While the Chinese consume the meat and shell of the turtle, the internal visceral organs are typically discarded. The visceral organs contain valuable components, including 8%-15% collagen and 8% blood. This study focused on extracting collagen from the internal visceral organs, while the remaining turtle parts were condensed into a refined product referred to as "Turtle refined," for cosmeceutical applications. We explored the acid solubilization (ASC) and pepsin solubilization (PSC) techniques to extract collagen. Preliminary findings indicate that the PSC method outperformed the ASC method in terms of collagen extraction. To characterize the collagen derived from the visceral organs and blood, SDS-PAGE, FTIR and DSC analyses were employed. Furthermore, we assessed the antioxidant property of the Turtle refined product, utilizing the DPPH radical scavenging activity test.

Effect of sun dry brewer spent yeast on chemical composition, in vitro digestibility, and ruminal degradation kinetics of wheat straw

BackgroundDry brewer spent yeast (DBSY) has high crude protein (CP) (43.2%) and metabolizable energy (14.3 MJ/kg) contents and it is an alternative animal feed for the improvement of the productive and reproductive performance of the animals. This study was conducted to evaluate the effect of DBSY on the chemical composition, in vitro digestibility, and in situ degradability of wheat straw (WS).MethodsLiquid brewer spent yeast (BSY) and water was mixed at a ratio of 1:5, respectively. The mixed debris soaked for 7 h in a 200-L plastic bucket. The water accumulated above the biomass was removed by tilting the container after the BSY was soaked in water. After three days of sun drying, DBSY was collected and removed with a scraper. The DBSY and wheat straw (WS) mixed uniformly. Different ratios of DBSY: WS (0:100, 10:90, 20:80, 30:70, 40:60, and 50:50, respectively, on a DM basis) were prepared. Based on these ratios, the experiment was subjected to a completely randomized design with six treatments comprising DBSY0, DBSY10, DBSY20, DBSY30, DBSY40, and DBSY50. Rumen liquor was collected from the three cannulated Boran-Friesian steers (42 months old and weighed 480 kg). The steers were fed natural pasture hay ad libitum supplemented with 2 kg concentrate per day/head. The sample was incubated in a test tube at 39 °C for 48 h with 10 ml of rumen fluid and 50 ml of buffer solution. The enzymatic digestion with acid pepsin solution was continued for another 48 h. Blank and standard samples were also incubated with buffered rumen fluid for correction and precision check-up of in vitro organic matter digestibility. Digestible organic matter in the dry matter (DOMD) was determined after drying and ashing the residues. The sample (3 g and 2 mm sieve size) with nylon bags (6.5 X 14 cm and 50 μm pore size) was entered sequentially and manually pressed deep into the liquid phase of the ventral sac of the rumen and incubated in the rumens (6, 12, 24, 48, 72, and 96 h) of three fistulated Boran × Holstein–Friesian steers. After removing the bags from the rumen, it was washed in running water for 20 min. The bags with residues were dried at 55 °C for 72 h in an air-forced oven, hot weighed, and finally, the residues recovered for further CP and neutral detergent fibre (NDF) analysis.ResultsThe highest ash, metabolizable energy, estimated digestible CP, DOMD, CP, Ca, P, Cu, Zn contents and the better DM, NDF, and CP ruminal degradability, and the lowest (P < 0.01) crude fibre, acid detergent fibre, NDF, K & Fe contents were observed in DBSY50 than the other DBSY inclusion level. In DBSY50, the potential degradability (PD) and effective degradability (ED) for DM of WS were improved by 52.22% and 56.17%, respectively. In DBSY50, PD and ED (NDF) in WS were increased by 60.34% and 65%, respectively. Similarly, in DBSY50, PD and ED (CP) of WS also improved by 54.20% and 63%, respectively.ConclusionThe inclusion of DBSY can improve the limited utilization of wheat straw, but this study should be verified with a feeding experiment to identify and recommend the most promising, economical and biological inclusion level of DBSY.

Amprenavir inhibits pepsin-mediated laryngeal epithelial disruption and E-cadherin cleavage in vitro.

Laryngopharyngeal reflux (LPR) causes chronic cough, throat clearing, hoarseness, and dysphagia and can promote laryngeal carcinogenesis. More than 20% of the US population suffers from LPR and there is no effective medical therapy. Pepsin is a predominant source of damage during LPR which disrupts laryngeal barrier function potentially via E-cadherin cleavage proteolysis and downstream matrix metalloproteinase (MMP) dysregulation. Fosamprenavir (FDA-approved HIV therapeutic and prodrug of amprenavir) is a pepsin-inhibiting LPR therapeutic candidate shown to rescue damage in an LPR mouse model. This study aimed to examine amprenavir protection against laryngeal monolayer disruption and related E-cadherin proteolysis and MMP dysregulation in vitro. Laryngeal (TVC HPV) cells were exposed to buffered saline, pH 7.4 or pH 4 ± 1 mg/mL pepsin ± amprenavir (10-60 min). Analysis was performed by microscopy, Western blot, and real time polymerase chain reaction (qPCR). Amprenavir (1 μM) rescued pepsin acid-mediated cell dissociation (p < .05). Pepsin acid caused E-cadherin cleavage indicative of regulated intramembrane proteolysis (RIP) and increased MMP-1,3,7,9,14 24-h postexposure (p < .05). Acid alone did not cause cell dissociation or E-cadherin cleavage. Amprenavir (10 μM) protected against E-cadherin cleavage and MMP-1,9,14 induction (p < .05). Amprenavir, at serum concentrations achievable provided the manufacturer's recommended dose of fosamprenavir for HIV, protects against pepsin-mediated cell dissociation, E-cadherin cleavage, and MMP dysregulation thought to contribute to barrier dysfunction and related symptoms during LPR. Fosamprenavir to amprenavir conversion by laryngeal epithelia, serum and saliva, and relative drug efficacies in an LPR mouse model are under investigation to inform development of inhaled formulations for LPR.

Melatonin: An anticancer molecule in esophageal squamous cell carcinoma: A mechanistic review

Several factors impact the mortality rate of patients with gastrointestinal cancers including late diagnosis, metastases to distance sites, and lack of efficacy of the conventional therapies. To reduce mortality rate, the novel effective remedies should be explored. Melatonin is an anti-inflammatory, antioxidant and oncostatic molecule and has been showed potential in controlling various malignancies. In the gastrointestinal tract, melatonin plays an important role via its membrane receptors of MT1 and MT2. It can diminish esophageal lesions resulting from acid–pepsin–bile contact and also inhibits expression of myosin light chain kinase as well as reduces its activity by regulating extracellular signal-transduction of protein kinase. The aim of the present study was to review the critical functions of melatonin in the prevention and treatment of esophageal squamous cell carcinoma including its influence on gastrointestinal pathology, oncostatic role and potential mechanisms. Particularly, the inhibitory function of melatonin on esophageal squamous cell carcinoma and its therapeutic effects are summarized. We suggest that melatonin co-treatment will enhance the efficacy of conventional treatments and survival times in patients with esophageal squamous cell carcinoma.

A Comprehensive Review on Ulcer and Their Treatment.

A peptic ulcer is a lesion (sore) on the stomach lining, or duodenum. Peptic ulcers are probably a twentieth-century condition. The ulcer disease continues to be a significant source of worldwide morbidity and mortality. The Gastrointestinal ulcers and duodenal ulcers are considered the two most extreme types of peptic ulcers. Peptic ulcers are found to be caused by an excess of violent factors including Hydrochloric acid (HCL) pepsin, refluxed bile leukotrienes (LT), reactive oxygen species (ROS) and protective factors, these include mucus-bicarbonate barrier functions, prostaglandins (PGs), mucosal blood flow, cell regeneration and migration, non-enzymatic and enzymatic and certain growth factors. The primary cause of peptic ulcer disease is pylori infection and the use of NSAIDs. This review article underscores the importance of a multidisciplinary approach in the management of ulcers to improve patient outcomes and quality of life.

Microscopic and Molecular Detection of Sarcocystis cruzi (Apicomplexa: Sarcocystidae) in the Heart Muscle of Cattle.

Sarcocystis is a genus of coccidian protozoa that at least seven species of it can parasitize cattle. The global prevalence of Sarcocystis is close to 100% in adult cattle. The main aim of this study was to identify the infection rate of Sarcocystis spp. in heart of cattle in Tehran, Iran by microscopy and PCR-RFLP methods. Totally, 100 bovine heart samples were collected from the main slaughterhouse of Shahriar, Meysam slaughterhouse, west of Tehran in 2016. At first, heart samples were completely examined for the presence of sarcocystic macrocysts. Then, for microscopic examination, 50 g of each heart was digested in sterile condition using pepsin acid digestion method. Then, the species of the parasite were detected by PCR-RFLP technique and sequencing. Overall, 97 of 100 of the heart muscle samples were infected with Sarcocystis. All the samples were detected as S. cruzi through similar patterns in PCR-RFLP. S. cruzi is the most common species in the heart of cattle slaughtered in Shahriar.

The Review on Peptic Ulcer Disease

Peptic ulcer is a chronic disease affecting up to 10% of the world’s population. The formation of peptic ulcers depends on the presence of gastric juice pH and the decrease in mucosal defenses. Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori (H. pylori) infection are the two major factors disrupting the mucosal resistance to injury. Conventional treatments of peptic ulcers, such as proton pump inhibitors (PPIs) and histamine-2 (H2) receptor antagonists, have demonstrated adverse effects, relapses, and various drug interactions. Peptic ulcer disease is characterized by discontinuation in the inner lining of the gastrointestinal (GI) tract because of gastric acid secretion or pepsin. It extends into the muscularis propria layer of the gastric epithelium. It usually occurs in the stomach and proximal duodenum. It may involve the lower esophagus, distal duodenum, or jejunum. Hence, this review presents common medicinal plants that may be used for the treatment or prevention of peptic ulcers. Peptic ulcer disease results from an imbalance between factors that protect the mucosa of the stomach and duodenum, and factors that cause damage to itPeptic ulcer disease presents with gastrointestinal symptoms similar to dyspepsia and can be difficult to distinguish clinically. It can have potentially serious complications such as bleeding or perforation, with a high risk of mortality.

Extraction and Characterization of Bioactive Fish By-Product Collagen as Promising for Potential Wound Healing Agent in Pharmaceutical Applications: Current Trend and Future Perspective.

Collagen is a structural protein naturally found in mammals. Vertebrates and other connective tissues comprise about 30% of an animal's overall protein. Collagen is used in a variety of applications including cosmetics, biomedical, biomaterials, food, and pharmaceuticals. The use of marine-based collagen as a substitute source is rapidly increasing due to its unique properties, which include the absence of religious restrictions, a low molecular weight, no risk of disease transmission, biocompatibility, and ease of absorption by the body system. This review discusses recent research on collagen extraction from marine-based raw material, specifically fish by-products. Furthermore, pretreatment on various sources of fish materials, followed by extraction methods, was described. The extraction procedures for acid soluble collagen (ASC) and pepsin soluble collagen (PSC) for fish collagen isolation are specifically discussed and compared. As a result, the efficacy of collagen yield was also demonstrated. The recent trend of extracting fish collagen from marine biomaterials has been summarized, with the potential to be exploited as a wound healing agent in pharmaceutical applications. Furthermore, background information on collagen and characterization techniques primarily related to the composition, properties, and structure of fish collagen are discussed.

A review on peptic ulcer

Peptic ulcer is a chronic disease affecting up to 10% of the world’s population. The formation of peptic ulcers depends on the presence of gastric juice pH and the decrease in mucosal defences. Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori (H. pylori) infection are the two major factors disrupting the mucosal resistance to injury. Peptic ulcer disease (PUD) is characterized by discontinuation in the inner lining of the gastrointestinal (GI) tract because of gastric acid secretion or pepsin. It extends into the muscularis propria layer of the gastric epithelium. It usually occurs in the stomach and proximal duodenum. It may involve the lower esophagus, distal duodenum, or jejunum. Epigastric pain usually occurs within 15-30 minutes following a meal in patients with a gastric ulcer; on the other hand, the pain with a duodenal ulcer tends to occur 2-3 hours after a meal. The treatments of peptic ulcers, such as proton pump inhibitors (PPIs) and histamine-2 (H2) receptor antagonists, have demonstrated adverse effects, relapses, and various drug interactions. On the other hand, medicinal plants and their chemical compounds are useful in the prevention and treatment of numerous diseases. Hence, this review presents common medicinal plants that may be used for the treatment or prevention of peptic ulcers.

Study on the interactions between nicotine γ-rezocine formic acid salt and pepsin: Multispectroscopy, molecular docking, and molecular dynamics simulation

Nicotine salt is a new form of nicotine introduced in tobacco products, and its interaction with biological macromolecules may be different from free nicotine, thereby affecting the absorption, metabolism, and physiological activity of nicotine in vivo. To explore the transport mechanism of nicotine salt into the gastrointestinal tract, this work firstly prepared a single crystal of nicotine γ-rezocine formic acid salt (named DBN) and then analyzed the interaction of DBN with pepsin (PEP) via multispectral methods and simulation technology. The results of single-crystal diffraction showed that the chemical formula of DBN was C17H20N2O4, and the crystal was closely bound by electrostatic interaction (ionic bond). DBN quenched the endogenous fluorescence of PEP by static quenching, and the binding strength between them was moderate (Ka = 8006 L·mol−1, 310 K). Thermodynamic parameters implied that the binding was a spontaneous process driven by hydrophobic forces. Investigations on the PEP conformation showed that DBN had a considerable effect on the amino acid microenvironment of PEP and reduced the hydrophobicity of PEP. Molecular docking and MD simulation results further supplemented and verified that DBN could stably combine in the hydrophobic cavity of PEP.

Preparation of immobilized pepsin for extraction of collagen from bovine hide.

In the extraction of collagens from mammalian tissues, the free pepsin used in the acid-pepsin extraction system is hard to recycle, and there is a risk of enzyme protein contamination in the extracted collagen products, which limits their applications. To solve this problem, an immobilized pepsin was successfully prepared via the covalent crosslinking of glutaraldehyde using a 3-aminopropyltriethoxysilane (APTES) surface modified silica clay as the support. The immobilized pepsin was applied for the extraction of collagen from bovine hide. The optimal immobilization process involves incubating pepsin with an initial concentration of 35 mg mL-1 and glutaraldehyde with 5% activated APTES modified silica clay at 25 °C for 60 min, by which the loading amount of pepsin was 220 mg g-1 and the activity of the immobilized pepsin was 4.2 U mg-1. The collagen extracted using acetic acid and the immobilized pepsin method retained its complete triple helix structure. This research thus details an effective separation method using pepsin for extraction of collagen via an acetic acid-enzyme method, where the extracted collagen may be a candidate for use in biomaterial applications.

Prevalence of Toxoplasma Gondii in Retail Fresh Meat Products from Free-range Chickens in Spain.

IntroductionToxoplasma gondii is one of the most prevalent zoonotic protozoan parasites worldwide and affects the vast majority of warm-blooded animal species, including humans. Postnatal infection in humans occurs through the ingestion of sporulated T. gondii oocysts or via the oral intake of parasite tissue cysts during the consumption of raw or undercooked meat. In this regard, given their high exposure to oocysts, chickens (Gallus domesticus) raised on the ground constitute a potential source of T. gondii.Material and MethodsFor the first time in Spain, a survey was undertaken in commercial retail free-range poultry. A total of 50 thighs from different animals were analysed. The samples were homogenised and an acid pepsin digestion procedure was applied prior to molecular analysis. Toxoplasma gondii DNA was isolated from meat by qPCR. Two sets of primers were used for DNA amplification targeting the specific sequence of a 529 bp repeat element and another set of primers was utilised for the surface antigen protein-1 gene.ResultsDNA extracted from 5 out of 50 tissue samples was positive for both genes by qPCR amplification.ConclusionThe 10% prevalence of Toxoplasma infection found in commercial free-range chickens raises public health issues.