Effect of carrageenans on some lipid metabolism components in vitro

The structure-function relationships and interaction between polysaccharides and intestinal microbiota: A review

The gut microbiota, as a complex ecosystem, can affect many physiological aspects of the host's diet, disease development, drug metabolism, and immune system regulation. Polysaccharides have various biological activities including antioxidant, anti-tumor, and regulating gut microbiota, etc. Polysaccharides cannot be degraded by human digestive enzymes. However, the interaction between gut microbiota and polysaccharides can lead to the degradation and utilization of polysaccharides. Disordered intestinal flora leads to diseases such as diabetes, hyperlipidemia, tumors, and diarrhea. Notably, polysaccharides can regulate the gut microbiota, promote the proliferation of probiotics and the SCFAs production, and thus improve the related-diseases and maintain body health. The relationship between polysaccharides and gut microbiota is gradually becoming clear. Nevertheless, the structure-function relationships between polysaccharides and gut microbiota still need further exploration. Hence, this paper systematically reviews the structure-function relationships between polysaccharides and gut microbiota from four aspects including molecular weight, glycosidic bonds, monosaccharide composition, and advanced structure. Moreover, this review outlines the effect of polysaccharides on gut microbiota metabolism and improves diseases by regulating gut microbiota. Furthermore, this article introduces the impact of gut microbiota on polysaccharide metabolism. The findings can provide the scientific basis for in-depth research on body health and reasonable diet.

Effects of High Pressure on In Vitro Bioavailability of Curcumin Loaded in Whey Protein Isolate/Carrageenan Composite Emulsion Gel: In Vitro Digestion Coupled with Cell Culture Model

The oral bioavailability of curcumin is inherently low, which significantly limits its application in food systems. The objective of this study was to evaluate the impact of high-pressure processing on the stability and bioaccessibility of curcumin within an emulsion gel during simulated gastrointestinal transit and to assess its cellular uptake. Our findings suggest that increasing pressure levels and high κ-carrageenan concentrations can enhance the stability of the curcumin delivery system. Elevated κ-CG concentrations were found to retard the action of proteases on dissociating protein molecules from the gel network. The emulsion gel effectively slowed the release of free fatty acids and reduced the curcumin release rate during the gastric phase. Scanning electron microscopy images revealed that higher pressures induced the formation of a more uniform and dense network structure in the gel. While the gel network structures were well-preserved after gastric digestion, they were disrupted into smaller particles following intestinal digestion, with particle size increasing with higher applied pressures. Cytotoxicity assays indicated that the digesta from the intestinal phase was highly toxic to Caco-2 cells. Among the tested samples, the emulsion gel prepared with 1.0% κ-CG at 600 MPa demonstrated the highest curcumin bioavailability, reaching 63.82 ± 7.10%. These findings underscore the potential of HPP-induced emulsion gels as a viable delivery system for enhancing curcumin bioaccessibility and cellular uptake.

Kappa-carrageenan in a pork-based high-fat diet inhibited lipid bioavailability through interactions with pork protein

κ-Carrageenan is a soluble dietary fiber widely used in meat products. Although its regulatory effect on glycolipid metabolism has been reported, the underlying mechanism remains unclear. The present study established a pork diet model for in vitro digestion to study how κ-carrageenan affected its digestive behavior and lipid bioavailability. The results revealed that κ-carrageenan addition to a pork-based high-fat diet reduced the rate of lipolysis and increased the number and size of lipid droplets in an in vitro digestion condition. However, κ-carrageenan did not inhibit lipolysis when lipids and κ-carrageenan were mixed directly or with the addition of pork protein. Furthermore, the pork protein in the diet significantly enhanced the inhibitory effect of κ-carrageenan on lipolysis with decreased proteolysis and raised hydrophobicity of protein hydrolysate. Our findings suggest that κ-carrageenan can inhibit dietary lipid bioavailability by interacting with pork protein in meat products or meat-based diets during digestion and indicate the positive role of carrageenan in the food industry to alleviate the excessive accumulation of lipids in the body.

Preparation, antibacterial activity, and structure-activity relationship of low molecular weight κ-carrageenan

κ-Carrageenan (KC) is a polysaccharide widely used in food industry. It has been widely studied for its excellent physicochemical and beneficial properties. However, the high molecular weight and high viscosity of KC make it difficult to be absorbed and to exert its' biological activities, thus limit its extensive industrial application. In order to solve this problem, five low molecular weight κ-carrageenans (DCPs) were prepared by the degradation of KC using hydrogen peroxide (H2O2) and ascorbic acid (AH2). The chemical compositions and structure characteristics of the DCPs were then determined. The results showed that H2O2 and AH2 could effectively degrade KC to DCPs, and DCPs remained the basic skeletal structure of KC. DCPs showed good antibacterial activities against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis. The Minimum Inhibitory Concentration (MIC) of DCPs with the highest antibacterial effects were 5.25, 4.5, 5.25, and 4.5 mg/mL, respectively. This is due to the underlying mechanism of DCPs that bind to the bacterial membrane proteins and change the membrane permeability, thus exerting antibacterial activity. In addition, Spearman's rank correlation and Ridge regression analysis revealed that the molecular weight and the contents of 3,6-anhydro-D-galactose, aldehyde group, carboxyl, and sulfate were the main structural characteristics affecting the antibacterial activity. Our findings reveal that the H2O2-AH2 degradation treatment could significantly improve the antibacterial activity of KC and provide insights into the quantitative structure-activity relationships of the antibacterial activity of DCPs.

Exploring carrageenan: From seaweed to biomedicine-A comprehensive review

Biomaterials are pivotal in the realms of tissue engineering, regenerative medicine, and drug delivery and serve as fundamental building blocks. Within this dynamic landscape, polymeric biomaterials emerge as the frontrunners, offering unparalleled versatility across physical, chemical, and biological domains. Natural polymers, in particular, captivate attention for their inherent bioactivity. Among these, carrageenan (CRG), extracted from red seaweeds, stands out as a naturally occurring polysaccharide with immense potential in various biomedical applications. CRG boasts a unique array of properties, encompassing antiviral, antibacterial, immunomodulatory, antihyperlipidemic, antioxidant, and antitumor attributes, positioning it as an attractive choice for cutting-edge research in drug delivery, wound healing, and tissue regeneration. This comprehensive review encapsulates the multifaceted properties of CRG, shedding light on the chemical modifications that it undergoes. Additionally, it spotlights pioneering research that harnesses the potential of CRG to craft scaffolds and drug delivery systems, offering high efficacy in the realms of tissue repair and disease intervention. In essence, this review celebrates the remarkable versatility of CRG and its transformative role in advancing biomedical solutions.

Edible Red Seaweed Hypnea asiatica Ameliorates High-Fat Diet-Induced Metabolic Diseases in Mice

Metabolic diseases, including obesity, diabetes, and fatty liver disease, are dramatically increasing around the world. Seaweed is low in calories and rich in many active ingredients that are necessary for maintaining good health, and is expected to be effective for preventing metabolic diseases. The purpose of this study was to examine the effects of a traditional Japanese edible seaweed Hypnea asiatica (H. asiatica) on obesity, using a mouse model. H. asiatica was dried and powdered, mixed with a high-fat diet, and fed to male C57BL/6J mice for 13 weeks. On the last day of the experiment, blood samples were collected under anesthesia and biochemical parameters such as lipids and adipokines were measured. Liver and adipose tissue were excised, weighed, and oxidant/antioxidant parameters were measured. Some mice were perfused with a fixative solution containing formalin, and tissue specimens were prepared. A glucose tolerance test was used to assess insulin resistance. The inhibition of lipase activity was evaluated in vitro. Thirteen-week supplementation with H. asiatica suppressed body weight gain, body fat accumulation, and blood glucose levels. H. asiatica also improved fatty liver and hypercholesterolemia, and reduced the oxidant and inflammatory parameters of serum and liver. H. asiatica increased fecal triglyceride excretion and polyphenol-rich ethanol extract of H. asiatica inhibited lipase activity in vitro. These results suggest that polysaccharides and polyphenols in H. asiatica may ameliorate obesity and diabetes by inhibiting intestinal fat absorption and reducing oxidative stress and inflammation. H. asiatica may be useful in preventing metabolic diseases such as obesity, diabetes, and fatty liver.

Carrageenan in meat: improvement in lipid metabolism due to Sirtuin1-mediated fatty acid oxidation and inhibited lipid bioavailability

Kappa-carrageenan (κ-CGN) is widely used in the meat industry. However, its impact on the host metabolism is less revealed. The current study investigated the effect of κ-CGN in pork-based diets on the lipid metabolism of male C57BL/6J mice. The κ-CGN supplement significantly suppressed the increase in body weight by 6.79 g on an average. Supplement of κ-CGN in high-fat diets significantly upregulated the genes and protein expression of Sirtuin1, which was accompanied by the increased gene expression of downstream fatty acids oxidation (Cpt1a and Acadl). The sirtuin1-mediated improvement of lipid metabolism was negatively associated with the levels of bile acids, especially for deoxycholic acid, 3β-cholic acid, glycodeoxycholic acid and glycolithocholic acid. Moreover, κ-CGN in high-fat diets inhibited lipid digestion and absorption, being associated with the decrease in lipid accumulation and improved serum lipid profile. These results highlighted the role of κ-CGN in alleviating diet-induced adiposity by promoting energy expenditure and suppressing the bioavailability of ingested lipids.

Sulfur content in foods and beverages and its role in human and animal metabolism: A scoping review of recent studies

Sulfur is a vital element that all living things require, being a component of proteins and other bio-organic substances. The various kinds and varieties of microbes in nature allow for the transformation of this element. It also should be emphasized that volatile sulfur compounds are typically present in food in trace amounts. Life cannot exist without sulfur, yet it also poses a potential health risk. The colon's sulfur metabolism, which is managed by eukaryotic cells, is much better understood than the S metabolism in gastrointestinal bacteria. Numerous additional microbial processes are anticipated to have an impact on the content and availability of sulfated compounds, as well as intestinal S metabolism. Hydrogen sulfide is the sulfur derivative that has attracted the most attention in relation to colonic health, but it is still unclear whether it is beneficial or harmful. Several lines of evidence suggest that sulfate-reducing bacteria or exogenous hydrogen sulfide may be the root cause of intestinal ailments, including inflammatory bowel diseases and colon cancer. Taurine serves a variety of biological and physiological purposes, including roles in inflammation and protection, additionally, low levels of taurine can be found in bodily fluids, and taurine is the primary sulfur component present in muscle tissue (serum and urine). The aim of this scoping review was to compile data from the most pertinent scientific works about S compounds' existence in food and their metabolic processes. The importance of S compounds in various food products and how these compounds can impact metabolic processes are both stressed in this paper.

Biological activity of algal derived carrageenan: A comprehensive review in light of human health and disease

Carrageenans are a family of natural linear sulfated polysaccharides derived from red seaweeds and used as a common food additive. Carrageenan's properties, impact on health, and aesthetic benefits have all been studied for a long time; however, the mechanisms are still unclear. In pharmaceutical aspects, carrageenan displayed potential antioxidant and immunomodulatory properties in both in vivo and in vitro action. It also contributes to potential disease-preventive activities through dynamic modulation of important intracellular signaling pathways, regulation of ROS buildup, and preservation of major cell survival and death processes which leads to potential drug development. Furthermore, the chemical synthesis of the current bioactive medicine with confirmational rearrangement may increase availability and bioactivity needs diligent examination. In this review, we give an up-to-date overview of recent research on Carrageenan with reference to health and therapeutic advantages. In addition, we have focused on structural conformation and its primary strategic deployment in disease prevention, as well as the mechanistic investigation of how it functions to combat various disease-preventive employed for future therapeutic interventions. This review may get new insights into the possible novel role of carrageenan and open up a novel disease-preventive mechanism and enhance human health.

Marine Bioactive Compounds Derived from Macroalgae as New Potential Players in Drug Delivery Systems: A Review

The marine algal ecosystem is characterized by a rich ecological biodiversity and can be considered as an unexploited resource for the discovery and isolation of novel bioactive compounds. In recent years, marine macroalgae have begun to be explored for their valuable composition in bioactive compounds and opportunity to obtain different nutraceuticals. In comparison with their terrestrial counterparts, Black Sea macroalgae are potentially good sources of bioactive compounds with specific and unique biological activities, insufficiently used. Macroalgae present in different marine environments contain several biologically active metabolites, including polysaccharides, oligosaccharides, polyunsaturated fatty acids, sterols, proteins polyphenols, carotenoids, vitamins, and minerals. As a result, they have received huge interest given their promising potentialities in supporting antitumoral, antimicrobial, anti-inflammatory, immunomodulatory, antiangiogenic, antidiabetic, and neuroprotective properties. An additional advantage of ulvans, fucoidans and carrageenans is the biocompatibility and limited or no toxicity. This therapeutic potential is a great natural treasure to be exploited for the development of novel drug delivery systems in both preventive and therapeutic approaches. This overview aims to provide an insight into current knowledge focused on specific bioactive compounds, which represent each class of macroalgae e.g., ulvans, fucoidans and carrageenans, respectively, as valuable potential players in the development of innovative drug delivery systems.

Beneficial effects of seaweed-derived dietary fiber: Highlights of the sulfated polysaccharides

Seaweeds and their derivatives are important bioresources of natural bioactive compounds. Nutritional studies indicate that dietary fibers derived from seaweeds have great beneficial potentials in human health and can be developed as functional food. Moreover, sulfated polysaccharides are more likely to be the main bioactive components which are widely distributed in various species of seaweeds including Phaeophyceae, Rhodophyceae and Chlorophyceae. The catabolism by gut microbiota of the seaweeds-derived dietary fibers (DFs) may be one of the pivotal pathways of their physiological functions. Therefore, in this review, we summarized the latest results of the physiological characteristics of seaweed-derived dietary fiber and highlighted the roles of sulfated polysaccharides in the potential regulatory mechanisms against disorders. Meanwhile, the effects of different types of seaweed-derived dietary fiber on gut microbiota were discussed. The analysis of the structure-function correlations and gut microbiota related mechanisms and will contribute to further better applications in food and biotherapeutics.

NMR spectroscopy for structural elucidation of sulfated polysaccharides from red seaweeds

Some sulfated polysaccharides from red seaweeds are used as hydrocolloids. In addition, it is well known that there are sulfated galactans (carrageenans and agarans) and sulfated mannans, with remarkable biological properties, as antiviral, antitumoral, immunomodulating, antiangiogenic, antioxidant, anticoagulant, and antithrombotic activities, and so on. Knowledge of the detailed structure of the active compound is essential and difficult to acquire. The substitution patterns of the polymer chain, as degree of sulfation and position of sulfate groups, as well as other substituents of the backbone, determine their biological behavior. NMR spectroscopy is a powerful and versatile tool for structural determination. It can be used for elucidation of structures of polysaccharides from new algal sources with novel substitutions or to detect the already known structures from different algal sources, and it could even help to monitor the quality of the active compound on a productive scale. In this review, the available information about NMR spectroscopy of sulfated polysaccharides from red seaweeds is revised and rationalized, to help other researchers working in different fields to study their structures. In addition, considerations about the effects of different structural features, as well as some recording conditions on the chemical shifts of the signals are analyzed.

Polysaccharide Structures and Their Hypocholesterolemic Potential

Several classes of polysaccharides have been described to have hypocholesterolemic potential, namely cholesterol bioaccessibility and bioavailability. This review will highlight the main mechanisms by which polysaccharides are known to affect cholesterol homeostasis at the intestine, namely the effect (i) of polysaccharide viscosity and its influence on cholesterol bioaccessibility; (ii) on bile salt sequestration and its dependence on the structural diversity of polysaccharides; (iii) of bio-transformations of polysaccharides and bile salts by the gut microbiota. Different quantitative structure–hypocholesterolemic activity relationships have been explored depending on the mechanism involved, and these were based on polysaccharide physicochemical properties, such as sugar composition and ramification degree, linkage type, size/molecular weight, and charge. The information gathered will support the rationalization of polysaccharides’ effect on cholesterol homeostasis and highlight predictive rules towards the development of customized hypocholesterolemic functional food.

Molar mass effect in food and health

It is demanded to supply foods with good quality for all the humans. With the advent of aging society, palatable and healthy foods are required to improve the quality of life and reduce the burden of finance for medical expenditure. Food hydrocolloids can contribute to this demand by versatile functions such as thickening, gelling, stabilising, and emulsifying, controlling texture and flavour release in food processing. Molar mass effects on viscosity and diffusion in liquid foods, and on mechanical and other physical properties of solid and semi-solid foods and films are overviewed. In these functions, the molar mass is one of the key factors, and therefore, the effects of molar mass on various health problems related to noncommunicable diseases or symptoms such as cancer, hyperlipidemia, hyperglycemia, constipation, high blood pressure, knee pain, osteoporosis, cystic fibrosis and dysphagia are described. Understanding these problems only from the viewpoint of molar mass is limited since other structural characteristics, conformation, branching, blockiness in copolymers such as pectin and alginate, degree of substitution as well as the position of the substituents are sometimes the determining factor rather than the molar mass. Nevertheless, comparison of different behaviours and functions in different polymers from the viewpoint of molar mass is expected to be useful to find a common characteristics, which may be helpful to understand the mechanism in other problems.

Carrageenan: Drug Delivery Systems and Other Biomedical Applications

Marine resources are today a renewable source of various compounds, such as polysaccharides, that are used in the pharmaceutical, medical, cosmetic, and food fields. In recent years, considerable attention has been focused on carrageenan-based biomaterials due to their multifunctional qualities, including biodegradability, biocompatibility, and non-toxicity, in addition to bioactive attributes, such as their antiviral, antibacterial, antihyperlipidemic, anticoagulant, antioxidant, antitumor, and immunomodulating properties. They have been applied in pharmaceutical formulations as both their bioactive and physicochemical properties make them suitable biomaterials for drug delivery, and recently for the development of tissue engineering. This article provides a review of recent research on the various types of carrageenan-based biomedical and pharmaceutical applications.

The Comparative Immunotropic Activity of Carrageenan, Chitosan and Their Complexes

The immunotropic activity of polyelectrolyte complexes (PEC) of κ-carrageenan (κ-CGN) and chitosan (CH) of various compositions was assessed in comparison with the initial polysaccharides in comparable doses. For this, two soluble forms of PEC, with an excess of CH (CH:CGN mass ratios of 10:1) and with an excess of CGN (CH: CGN mass ratios of 1:10) were prepared. The ability of PEC to scavenge NO depended on the content of the κ-CGN in the PEC. The ability of the PEC to induce the synthesis of pro-inflammatory (tumor necrosis factor-α (TNF-α)) and anti-inflammatory (interleukine-10 (IL-10)) cytokines in peripheral blood mononuclear cell was determined by the activity of the initial κ-CGN, regardless of their composition. The anti-inflammatory activity of PEC and the initial compounds was studied using test of histamine-, concanavalin A-, and sheep erythrocyte immunization-induced inflammation in mice. The highest activity of PEC, as well as the initial polysaccharides κ-CGN and CH, was observed in a histamine-induced exudative inflammation, directly related to the activation of phagocytic cells, i.e., macrophages and neutrophils.

Effect of Carrageenans on Vegetable Jelly in Humans with Hypercholesterolemia

Changes in lipid profile constitute the main risk factor for cardiovascular diseases. Algae extracted carrageenans are long-chain polysaccharides and their ability to form gels provides for the formation of vegetable jelly. The objective was to evaluate the bioactive potential of carrageenan (E407) in the lipid profile, after ingestion of jelly. A total of 30 volunteers of both sexes, aged 20-64 years and with total cholesterol (TC) values ≥200 mg/dL, who ingested 100 mL/day of jelly for 60 days, were studied. All had two venous blood collections: before starting the jelly intake and after 60 days. At both times, TC, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and triglycerides (TG), were evaluated using commercial kits and spectrophotometer. The statistics were performed using the SPSS 25.0 software and p < 0.05 were considered statistically significant. Serum values after 60 days of jelly intake revealed a statistically significant decrease in TC levels (5.3%; p = 0.001) and LDL-C concentration (5.4%; p = 0.048) in females. The daily intake of vegetable jelly for 60 days showed a reduction in serum TC and LDL-C levels in women, allowing us to conclude that carrageenan has bioactive potential in reducing TC concentration.