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11,398 result(s) for "alginates"
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Comparable efficacy of generic and original alginate for symptom control in PPI-refractory GERD
Gastroesophageal reflux disease (GERD) is a prevalent global condition, affecting 18.1–27.8% of North Americans and 6.3–18.3% of the Thai population. While proton pump inhibitors (PPIs) are the first-line treatment, only about one-third of patients achieve adequate symptom control. Alginate-based medications in combination with PPIs have shown promise, but the comparative effectiveness of generic versus original alginates remains unexplored. To compare the effectiveness of generic alginate (ONE GERD) versus original alginate (Gaviscon Dual Action Suspension) in combination with PPIs for treating GERD symptoms in patients who failed standard PPI therapy.This multicenter prospective randomized controlled non-inferiority trial included 48 patients who failed standard-dose PPI treatment. Patients were randomized to receive either generic or original alginate four times daily for 28 days. Treatment response was evaluated using the Reflux Disease Questionnaire (RDQ) at days 7 and 28. At day 7, both groups showed identical response rates of 45.83%. By day 28, response rates increased to 54.17% for generic alginate and 70.83% for original alginate ( p  = 0.23). Total RDQ scores and symptom-free rates showed no significant differences between groups at both time points. Adverse event rates were comparable (16.67% vs. 8.33%, p  = 0.66). Analysis of specific symptoms (heartburn, chest pain, and regurgitation) revealed similar improvements in both groups throughout the study period. This study provides evidence supporting the therapeutic equivalence of the generic alginate (ONE GERD) to the original formulation (Gaviscon Dual Action Suspension) in treating symptoms for patients with GERD who have failed PPI therapy. Crucially, the comparable efficacy and safety, coupled with the inherent lower cost of generic medications, suggest significant economic benefits and the potential for wider patient access to effective GERD management. This makes generic alginate a viable and attractive alternative in clinical practice, particularly in resource-limited settings or for patients facing financial constraints, thereby contributing to more equitable healthcare solutions without compromising therapeutic outcomes.
Structure Characteristics, Biochemical Properties, and Pharmaceutical Applications of Alginate Lyases
Alginate, the most abundant polysaccharides of brown algae, consists of various proportions of uronic acid epimers α-L-guluronic acid (G) and β-D-mannuronic acid (M). Alginate oligosaccharides (AOs), the degradation products of alginates, exhibit excellent bioactivities and a great potential for broad applications in pharmaceutical fields. Alginate lyases can degrade alginate to functional AOs with unsaturated bonds or monosaccharides, which can facilitate the biorefinery of brown algae. On account of the increasing applications of AOs and biorefinery of brown algae, there is a scientific need to explore the important aspects of alginate lyase, such as catalytic mechanism, structure, and property. This review covers fundamental aspects and recent developments in basic information, structural characteristics, the structure–substrate specificity or catalytic efficiency relationship, property, molecular modification, and applications. To meet the needs of biorefinery systems of a broad array of biochemical products, alginate lyases with special properties, such as salt-activated, wide pH adaptation range, and cold adaptation are outlined. Withal, various challenges in alginate lyase research are traced out, and future directions, specifically on the molecular biology part of alginate lyases, are delineated to further widen the horizon of these exceptional alginate lyases.
Structures, Properties and Applications of Alginates
Alginate is a hydrocolloid from algae, specifically brown algae, which is a group that includes many of the seaweeds, like kelps and an extracellular polymer of some bacteria. Sodium alginate is one of the best-known members of the hydrogel group. The hydrogel is a water-swollen and cross-linked polymeric network produced by the simple reaction of one or more monomers. It has a linear (unbranched) structure based on d-mannuronic and l-guluronic acids. The placement of these monomers depending on the source of its production is alternating, sequential and random. The same arrangement of monomers can affect the physical and chemical properties of this polysaccharide. This polyuronide has a wide range of applications in various industries including the food industry, medicine, tissue engineering, wastewater treatment, the pharmaceutical industry and fuel. It is generally recognized as safe when used in accordance with good manufacturing or feeding practice. This review discusses its application in addition to its structural, physical, and chemical properties.
Characterization of alginate extracted from Sargassum latifolium and its use in Chlorella vulgaris growth promotion and riboflavin drug delivery
Alginates derived from macroalgae have been widely used in a variety of applications due to their stability, biodegradability and biocompatibility. Alginate was extracted from Egyptian Sargassum latifolium thallus yielding 17.5% w/w. The chemical composition of S. latifolium is rich in total sugars (41.08%) and uronic acids (47.4%); while, proteins, lipids and sulfates contents are 4.61, 1.13 and 0.09%, respectively. NMR, FTIR and TGA analyses were also performed. Crystallinity index (0.334) indicates alginate semicrystalline nature. Sodium alginate hydrolysate was evaluated as Chlorella vulgaris growth promoter. The highest stimulation (0.7 g/L biomass) was achieved by using 0.3 g/L alginate hydrolysate supplementation. The highest total soluble proteins and total carbohydrates were 179.22 mg/g dry wt and 620.33 mg/g dry wt, respectively. The highest total phenolics content (27.697 mg/g dry wt.), guaiacol peroxidase activity (2.899 µmol min −1  g −1 ) were recorded also to 0.3 g/L alginate hydrolysate supplementation. Riboflavin-entrapped barium alginate-Arabic gum polymeric matrix (beads) was formulated to achieve 89.15% optimum drug entrapment efficiency (EE%). All formulations exhibited prolonged riboflavin release over 120 min in simulated gastric fluid, followed Higuchi model (R 2  = 0.962–0.887) and Korsmeyer–Peppas model with Fickian release (n ranges from 0.204 to 0.3885).
Bacterial alginate metabolism: an important pathway for bioconversion of brown algae
Brown macroalgae have attracted great attention as an alternative feedstock for biorefining. Although direct conversion of ethanol from alginates (major components of brown macroalgae cell walls) is not amenable for industrial production, significant progress has been made not only on enzymes involved in alginate degradation, but also on metabolic pathways for biorefining at the laboratory level. In this article, we summarise recent advances on four aspects: alginate, alginate lyases, different alginate-degrading systems, and application of alginate lyases and associated pathways. This knowledge will likely inspire sustainable solutions for further application of both alginate lyases and their associated pathways.
Advances in Research on the Bioactivity of Alginate Oligosaccharides
Alginate is a natural polysaccharide present in various marine brown seaweeds. Alginate oligosaccharide (AOS) is a degradation product of alginate, which has received increasing attention due to its low molecular weight and promising biological activity. The wide-ranging biological activity of AOS is closely related to the diversity of their structures. AOS with a specific structure and distinct applications can be obtained by different methods of alginate degradation. This review focuses on recent advances in the biological activity of alginate and its derivatives, including their anti-tumor, anti-oxidative, immunoregulatory, anti-inflammatory, neuroprotective, antibacterial, hypolipidemic, antihypertensive, and hypoglycemic properties, as well as the ability to suppress obesity and promote cell proliferation and regulate plant growth. We hope that this review will provide theoretical basis and inspiration for the high-value research developments and utilization of AOS-related products.
Alginate Lyases from Marine Bacteria: An Enzyme Ocean for Sustainable Future
The cell wall of brown algae contains alginate as a major constituent. This anionic polymer is a composite of β-d-mannuronate (M) and α-l-guluronate (G). Alginate can be degraded into oligosaccharides; both the polymer and its products exhibit antioxidative, antimicrobial, and immunomodulatory activities and, hence, find many commercial applications. Alginate is attacked by various enzymes, collectively termed alginate lyases, that degrade glycosidic bonds through β-elimination. Considering the abundance of brown algae in marine ecosystems, alginate is an important source of nutrients for marine organisms, and therefore, alginate lyases play a significant role in marine carbon recycling. Various marine microorganisms, particularly those that thrive in association with brown algae, have been reported as producers of alginate lyases. Conceivably, the marine-derived alginate lyases demonstrate salt tolerance, and many are activated in the presence of salts and, therefore, find applications in the food industry. Therefore, this review summarizes the structural and biochemical features of marine bacterial alginate lyases along with their applications. This comprehensive information can aid in the expansion of future prospects of alginate lyases.
Multi-Functional Alginate Lyase AlgVR7 from Vibrio rumoiensis: Structural Insights and Catalytic Mechanisms
In this study, we identified AlgVR7, a novel bifunctional alginate lyase from Vibrio rumoiensis and characterized its biochemical properties and substrate specificity. Sequence alignment analysis inferred the key residues K267, H162, N86, E189, and T244 for AlgVR7 catalysis, and it is derived from the PL7 family; exhibited high activity towards sodium alginate, polyM (PM), and polyG (PG); and can also degrade polygalacturonic acid (PGA) efficiently, with the highest affinity and catalytic efficiency for the MG block of the substrate. The optimal temperature and pH for AlgVR7 were determined to be 40 °C and pH 8, respectively. The enzyme activity of AlgVR7 was maximum at 40 °C, 40% of the enzyme activity was retained after incubation at 60 °C for 60 min, and enzyme activity was still present after 60 min incubation. AlgVR7 activity was stimulated by 100 Mm NaCl, indicating a halophilic nature and suitability for marine environments. Degradation products analyzed using ESI-MS revealed that the enzyme primarily produced trisaccharides and tetrasaccharides. At 40 °C and pH 8.0, its Km values for sodium alginate, PM, and PG were 16.67 μmol, 13.12 μmol, and 22.86 μmol, respectively. Structural analysis and molecular docking studies unveiled the key catalytic residues involved in substrate recognition and interaction. Glu167 was identified as a critical residue for the PL7_5 subfamily, uniquely playing an essential role in alginate decomposition. Overall, AlgVR7 exhibits great potential as a powerful bifunctional enzyme for the efficient preparation of alginate oligosaccharides, with promising applications in biotechnology and industrial fields.
Alginate-Based Biomaterials in Tissue Engineering and Regenerative Medicine
Today, with the salient advancements of modern and smart technologies related to tissue engineering and regenerative medicine (TE-RM), the use of sustainable and biodegradable materials with biocompatibility and cost-effective advantages have been investigated more than before. Alginate as a naturally occurring anionic polymer can be obtained from brown seaweed to develop a wide variety of composites for TE, drug delivery, wound healing, and cancer therapy. This sustainable and renewable biomaterial displays several fascinating properties such as high biocompatibility, low toxicity, cost-effectiveness, and mild gelation by inserting divalent cations (e.g., Ca2+). In this context, challenges still exist in relation to the low solubility and high viscosity of high-molecular weight alginate, high density of intra- and inter-molecular hydrogen bonding, polyelectrolyte nature of the aqueous solution, and a lack of suitable organic solvents. Herein, TE-RM applications of alginate-based materials are deliberated, focusing on current trends, important challenges, and future prospects.
Magnesium Alginate in Gastro-Esophageal Reflux: A Randomized Multicenter Cross-Over Study in Infants
The aims of this study were to evaluate the efficacy of magnesium alginate in decreasing functional regurgitation symptoms in infants, and to assess the cost–benefit ratio of magnesium alginate compared to a thickened formula. A multicenter perspective cross-over study was conducted in formula-fed infants with persisting regurgitation, randomly assigned to receive two weeks of a magnesium-alginate-based formulation followed by two weeks of thickened formula, or vice-versa. Infants, exclusively breast-fed, were followed up for two weeks while receiving magnesium alginate. Symptoms of gastroesophageal reflux (GER) were evaluated through the Infant Gastroesophageal Reflux Questionnaire Revised (I-GERQ-R). Direct cost of treatments was also calculated. Seventy-two infants completed the study. We found a significant reduction of I-GERQ-R scores over time (F = 55.387; p < 0.001) in all groups with no difference between the sequences of administration (F = 0.268; p = 0.848) in formula-fed infants and between exclusively breast-fed and formula-fed infants receiving magnesium alginate (t = 1.55; p = 0.126). The mean cost savings per infant was € 4.60 (±11.2) in formula-fed infants treated with magnesium alginate compared to thickened formula (t = 2.91, p < 0.0005). Conclusions were that the magnesium-alginate formulation reduces GER symptoms both in formula-fed and breast-fed infants. In formula-fed infants, clinical efficacy is similar to thickened formulas with a slightly lower cost of treatment.