Alginate oligosaccharides can maintain activities of lysosomes under low pH condition

The therapeutic effect and possible mechanisms of alginate oligosaccharide on metabolic syndrome by regulating gut microbiota

Metabolic syndrome (MetS) is a disease condition incorporating the abnormal accumulation of various metabolic components, including overweight or abdominal obesity, insulin resistance and abnormal glucose tolerance, hypertension, atherosclerosis, or dyslipidemia. It has been proved that the gut microbiota and microbial-derived products play an important role in regulating lipid metabolism and thus the onset and development of MetS. Previous studies have demonstrated that oligosaccharides with prebiotic effects, such as chitosan oligosaccharides, can regulate the structure of the microbial community and its derived products to control weight and reduce MetS associated with obesity. Alginate oligosaccharides (AOS), natural products extracted from degraded alginate salts with high solubility and extensive biological activity, have also been found to modulate gut microbiota. This review aims to summarize experimental evidence on the positive effects of AOS on different types of MetS while providing insights into mechanisms through which AOS regulates gut microbiota for preventing and treating MetS.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2021-2022

The use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates is a well-established technique and this review is the 12th update of the original article published in 1999 and brings coverage of the literature to the end of 2022. As with previous review, this review also includes a few papers that describe methods appropriate to analysis by MALDI, such as sample preparation, even though the ionization method is not MALDI. The review follows the same format as previous reviews. It is divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of computer software for structural identification. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other general areas such as medicine, industrial processes, natural products and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. MALDI is still an ideal technique for carbohydrate analysis, particularly in its ability to produce single ions from each analyte and advancements in the technique and range of applications show little sign of diminishing.

Cold plasma treatment with alginate oligosaccharide improves the digestive stability and bioavailability of nutrient-delivered particles: An in vitro INFOGEST gastrointestinal study

To improve the stability and bioavailability of the delivered hydrophobic nutrients, the zein-based delivery system was modified by alginate oligosaccharide (AOS), cold plasma (CP) treatments, and synergistically. The digestive behavior of each was investigated in an INFOGEST static in vitro digestion model. The results showed that AOS and CP treatments and their synergistic effects improved the dispersion and stability of the delivery system, leading to a more concentrated particle size distribution and higher particle surface charge. Both CP treatments and AOS increased the release rate of Curcumin (Cur) at small intestine (11.8 % to 20.5 % and 11.8 % to 24.64 %, respectively), and the synergistic effect was higher (11.8 % to 43.84 %). The wall material modified showed a higher encapsulation efficiency of Cur (52.83 % to 85.17 %). Cur release rate measurements showed that the wall material modified could have a positive effect on the slow release of Cur. SDS-page electrophoresis revealed that the slow release was due to the enhanced resistance of wall material to digestive fluids. Thus, treatment with AOS and CP treatments, and the synergism are suitable for modifying zein-based delivery systems for the encapsulation, stabilization, and slow release of hydrophobic nutrients during digestion in the field of functional foods.

The role of functional oligosaccharides as prebiotics in ulcerative colitis

The incidence rate of ulcerative colitis (UC) has increased significantly over the past decades and it places an increasing burden on health and social systems. The current studies on UC implicate a strong correlation between host gut microbiota immunity and the pathogenesis of UC. Meanwhile, more and more functional oligosaccharides have been reported as prebiotics to alleviate UC, since many of them can be metabolized by gut microbiota to produce short-chain fatty acids (SCFAs). The present review is focused on the structure, sources and specific applications of various functional oligosaccharides related to the prevention and treatment of UC. The available evidence for the usage of functional oligosaccharides in UC treatment are summarized, including fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), chito-oligosaccharides (COS), alginate-oligosaccharides (AOS), xylooligosaccharides (XOS), stachyose and inulin.

Cloning and Characterization of a Novel Alginate Lyase from Paenibacillus sp. LJ-23

As a low molecular weight alginate, alginate oligosaccharides (AOS) exhibit improved water solubility, better bioavailability, and comprehensive health benefits. In addition, their biocompatibility, biodegradability, non-toxicity, non-immunogenicity, and gelling capability make them an excellent biomaterial with a dual curative effect when applied in a drug delivery system. In this paper, a novel alginate lyase, Algpt, was cloned and characterized from a marine bacterium, Paenibacillus sp. LJ-23. The purified enzyme was composed of 387 amino acid residues, and had a molecular weight of 42.8 kDa. The optimal pH of Algpt was 7.0 and the optimal temperature was 45 °C. The analysis of the conserved domain and the prediction of the three-dimensional structure indicated that Algpt was a novel alginate lyase. The dominant degradation products of Algpt on alginate were AOS dimer to octamer, depending on the incubation time, which demonstrated that Algpt degraded alginate in an endolytic manner. In addition, Algpt was a salt-independent and thermo-tolerant alginate lyase. Its high stability and wide adaptability endow Algpt with great application potential for the efficient preparation of AOS with different sizes and AOS-based products.

Biophysico-Chemical Properties of Alginate Oligomers Obtained by Acid and Oxidation Depolymerization

The aim of the study was to obtain alginate oligosaccharides by using two degradation methods of sodium alginate (SA): with hydrochloric acid (G—guluronate, M—mannuronate and G + M fractions) and hydrogen peroxide (HAS—hydrolyzed SA), in order to assess and compare their biological activity and physico-chemical properties, with an attempt to produce gels from the obtained hydrolysates. The efficiency of each method was determined in order to select the fastest and most efficient process. The ferric ion reducing antioxidant power (FRAP), the ability to scavenge DPPH free radicals, rheological properties, Fourier Transformed Spectroscopy (FTIR) and the microbiological test against Escherichia coli and Staphylococcus aureus were performed. In order to check the functional properties of the obtained oligosaccharides, the texture profile analysis was assessed. The hydrolysis yield of acid SA depolymerization was 28.1% and from hydrogen peroxide SA, depolymerization was 87%. The FTIR analysis confirmed the degradation process by both tested methods in the fingerprint region. The highest ferric reducing antioxidant power was noted for HSA (34.7 µg), and the highest hydroxyl radical scavenging activity was obtained by G fraction (346 µg/Trolox ml). The complete growth inhibition (OD = 0) of alginate hydrolysates was 1%. All tested samples presented pseudoplastic behavior, only HSA presented the ability to form gel.

Potential applications of alginate oligosaccharides for biomedicine - A mini review

Extensive research on marine algae, especially on their health-promoting properties, has been conducted. Various ingredients with potential biomedical applications have been discovered and extracted from marine algae. Alginate oligosaccharides are low molecular weight alginate polysaccharides present in cell walls of brown algae. They exhibit various health benefits such as anti-inflammatory, anti-microbial, anti-oxidant, anti-tumor and immunomodulation. Their low-toxicity, non-immunogenicity, and biodegradability make them an excellent material in biomedicine. Alginate oligosaccharides can be chemically or biochemically modified to enhance their biological activity and potential in pharmaceutical applications. This paper provides a brief overview on alginate oligosaccharides characteristics, modification patterns and highlights their vital health promoting properties.