Alginic acid isolated from Sargassum wightii exhibits anti-inflammatory potential on type II collagen induced arthritis in experimental animals

Marine algae: A treasure trove of bioactive anti-inflammatory compounds

This comprehensive review examines the diverse classes of pharmacologically active compounds found in marine algae and their promising anti-inflammatory effects. The review covers various classes of anti-inflammatory compounds sourced from marine algae, including phenolic compounds, flavonoids, terpenoids, caretenoids, alkaloids, phlorotannins, bromophenols, amino acids, peptides, proteins, polysaccharides, and fatty acids. The anti-inflammatory activities of marine algae-derived compounds have been extensively investigated using in vitro and in vivo models, demonstrating their ability to inhibit pro-inflammatory mediators, such as cytokines, chemokines, and enzymes involved in inflammation. Moreover, marine algae-derived compounds have exhibited immunomodulatory properties, regulating immune cell functions and attenuating inflammatory responses. Specific examples of compounds with notable anti-inflammatory activities are highlighted. This review provides valuable insights for researchers in the field of marine anti-inflammatory pharmacology and emphasizes the need for further research to harness the pharmacological benefits of marine algae-derived compounds for the development of effective and safe therapeutic agents.

Effects of Alginic Acid on the Porcine Granulosa Cells and Maturation of Porcine Oocytes

SCOPE

Alginic acid (AA) from brown algae is a marine organic compound. There is extensive use of AA in the food industry and healthcare, suggesting a high probability of AA exposure. The present study investigates the effects of AA on porcine ovarian granulosa cells (GCs) and oocytes to explore its mechanism in female reproduction because of its adverse effects on reproduction.

METHODS AND RESULTS

The study adds 20 µM AA to the porcine primary ovarian GCs medium and porcine oocyte in vitro maturation (IVM) medium. Estrogen and progesterone levels are downregulated in GCs. Reactive oxygen species are excessive, and the antioxidant capacity declines. Then mitochondria-mediated apoptosis pathway is involved in GCs apoptosis. In addition, scores of autophagosomes are found in the experimental cells. Furthermore, AA significantly inhibits the proliferation of GCs around cumulus-oocyte complexes (COCs) accompanied by abnormal spindle assembly, chromosome arrangement disorder, and aberrant cortical granules distribution in oocytes, leading to a decreased oocyte maturation rate.

CONCLUSION

These findings suggest that 20 µM AA is toxic to sow reproduction by interfering with estrogen production, oxidative stress, mitochondria-mediated apoptosis, autophagy in GCs of sows, and oocyte maturation.

Alginates Combined with Natural Polymers as Valuable Drug Delivery Platforms

Alginates (ALG) have been used in biomedical and pharmaceutical technologies for decades. ALG are natural polymers occurring in brown algae and feature multiple advantages, including biocompatibility, low toxicity and mucoadhesiveness. Moreover, ALG demonstrate biological activities per se, including anti-hyperlipidemic, antimicrobial, anti-reflux, immunomodulatory or anti-inflammatory activities. ALG are characterized by gelling ability, one of the most frequently utilized properties in the drug form design. ALG have numerous applications in pharmaceutical technology that include micro- and nanoparticles, tablets, mucoadhesive dosage forms, wound dressings and films. However, there are some shortcomings, which impede the development of modified-release dosage forms or formulations with adequate mechanical strength based on pure ALG. Other natural polymers combined with ALG create great potential as drug carriers, improving limitations of ALG matrices. Therefore, in this paper, ALG blends with pectins, chitosan, gelatin, and carrageenans were critically reviewed.

Seaweed Exhibits Therapeutic Properties against Chronic Diseases: An Overview

Seaweeds or marine macroalgae are known for producing potentially bioactive substances that exhibit a wide range of nutritional, therapeutic, and nutraceutical properties. These compounds can be applied to treat chronic diseases, such as cancer, cardiovascular disease, osteoporosis, neurodegenerative diseases, and diabetes mellitus. Several studies have shown that consumption of seaweeds in Asian countries, such as Japan and Korea, has been correlated with a lower incidence of chronic diseases. In this study, we conducted a review of published papers on seaweed consumption and chronic diseases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method for this study. We identified and screened research articles published between 2000 and 2021. We used PubMed and ScienceDirect databases and identified 107 articles. This systematic review discusses the potential use of bioactive compounds of seaweed to treat chronic diseases and identifies gaps where further research in this field is needed. In this review, the therapeutic and nutraceutical properties of seaweed for the treatment of chronic diseases such as neurodegenerative diseases, obesity, diabetes, cancer, liver disease, cardiovascular disease, osteoporosis, and arthritis were discussed. We concluded that further study on the identification of bioactive compounds of seaweed, and further study at a clinical level, are needed.

Alginic acid induces oxidative stress-mediated hormone secretion disorder, apoptosis and autophagy in mouse granulosa cells and ovaries

Alginic acid (AA) is a kind of polysaccharide extracted from brown seaweeds and has been widely used in food industry. Certain positive effects of AA, such as anti-inflammation and anti-allergy, have been reported. Nevertheless, as a potential chemical contaminant of the environment, its impact on female reproductive system remains to be investigated. The purpose of this study is to explore the impact of AA on ovary and to investigate the further cellular mechanism. Primarily, in vitro cultured mouse ovary granulosa cells (GCs) were treated with AA at a concentration of 10μM for 24 h. The cells and supernatant were collected and subjected to further measures. The results demonstrated that after being treated with 10μM AA for 24 h the levels of estradiol and progesterone in supernatant were down-regulated. And excessive reactive oxygen species (ROS) and declined antioxidant capacity were also determined. Additionally, a large number of apoptotic bodies and autophagic vesicles were found in the experimental cells, and the mitochondria-mediated apoptotic pathway was demonstrated to play a main role in GCs apoptosis. To further investigate the effect of AA on ovary, the female ICR mice were administered with AA (10 mg/ kg bodyweight) intraperitoneally for successive 35 days, and the estrus phase was recorded simultaneously. After exposure, the ovaries and blood samples were collected for further analysis. The results revealed that the estrus period of the mice was shortened and the interestrus period was extended after being treated with AA for 35 days. At the organismal level, the numbers of antral follicles and atresia follicles increased and the levels of pro-apoptosis and autophagy-related proteins were detected upregulated after AA treatment. Taken together, both in vivo and in vitro data suggested that AA has toxicity on female reproduction by disrupting estrogen production and inducing oxidative stress, mitochondria-mediated apoptosis and autophagy. Our results provide new scientific basis and the concern for controlling the increasing use of AA.

Structures, properties and application of alginic acid: A review

Alginic acid is a natural polysaccharide, which has been widely concerned and applied due to its excellent water solubility, film formation, biodegradability and biocompatibility. This paper briefly describes the source, properties, structure and application of sodium alginate by summarizing and analyzing the current literature. This paper reviews the application of sodium alginate in the fields of food industry, catalyst, health, water treatment, packaging, immobilized cells, and looks forward to its application prospects.

Marine-Derived Surface Active Agents: Health-Promoting Properties and Blue Biotechnology-Based Applications

Surface active agents are characterized for their capacity to adsorb to fluid and solid-water interfaces. They can be classified as surfactants and emulsifiers based on their molecular weight (MW) and properties. Over the years, the chemical surfactant industry has been rapidly increasing to meet consumer demands. Consequently, such a boost has led to the search for more sustainable and biodegradable alternatives, as chemical surfactants are non-biodegradable, thus causing an adverse effect on the environment. To these ends, many microbial and/or marine-derived molecules have been shown to possess various biological properties that could allow manufacturers to make additional health-promoting claims for their products. Our aim, in this review article, is to provide up to date information of critical health-promoting properties of these molecules and their use in blue-based biotechnology (i.e., biotechnology using aquatic organisms) with a focus on food, cosmetic and pharmaceutical/biomedical applications.

In vivo anti-inflammatory and anti-allergic activities of cynaroside evaluated by using hydrogel formulations

OBJECTIVES

Cynaroside (CYN) is the predominant derivative of luteolin in aerial parts of Bidens tripartita which has been used in folk medicine as a diaphoretic, diuretic, antiseptic and anti-inflammatory agent. In our study, alginate (ALG), which is an anionic polymer with bioadhesive properties, was used as a CYN carrier, and multiple hydrogel formulations were created. Additionally, the present study evaluated the in vivo anti-inflammatory and anti-allergic activities of all preparations.

METHODS

Novel gel formulations as topical carriers for CYN obtained from B. tripartita were developed and characterized. The bioadhesive properties of the designed preparations were also evaluated in an ex vivo model using the skin of hairless mice. In vitro CYN release from all formulations was examined and analysed by HPLC. Histopathological evaluation of mouse skin sections stained with H&E after carrageenan and oxazolone administration was also carried out. In addition, the influence of CYN on cell proliferation was examined by the PCNA staining method.

RESULTS

The results showed that 10 % CYN inhibited the release of anti-inflammatory mediators, and both tested concentrations, which included 5 % and 10 % (2 mg and 20 mg CYN per site, respectively), reduced oxazolone-induced ear swelling. Histopathological examination of the samples revealed a marked reduction in paw skin and ear tissue inflammation and in inflammatory infiltrates. The influence of CYN on cell proliferation was examined by the PCNA staining method, and the staining and distribution of PCNA-immunoreactive (PCNA-IR) cells were observed. After the application of the 5 % and 10 % hydrogels, the investigated samples showed decreased nuclear immunoreactivity to PCNA, which was similar to that of the control. Moreover, after application of the placebo formulation, fewer PCNA-IR cells were also observed.

CONCLUSION

The obtained data suggest that the topical application of CYN significantly reduces the number of T cells, mast cells and histiocytes in mouse skin with inflammation or atopic dermatitis.

Sargassum Seaweed as a Source of Anti-Inflammatory Substances and the Potential Insight of the Tropical Species: A Review

Sargassum is recognized both empirically and scientifically as a potential anti-inflammatory agent. Inflammation is an important response in the body that helps to overcome various challenges to body homeostasis such as microbial infections, tissue stress, and certain injuries. Excessive and uncontrolled inflammatory conditions can affect the pathogenesis of various diseases. This review aims to explore the potential of Sargassum's anti-inflammatory activity, not only in crude extracts but also in sulfated polysaccharides and purified compounds. The tropical region has a promising availability of Sargassum biomass because its climate allows for the optimal growth of seaweed throughout the year. This is important for its commercial utilization as functional ingredients for both food and non-food applications. To the best of our knowledge, studies related to Sargassum's anti-inflammatory activity are still dominated by subtropical species. Studies on tropical Sargassum are mainly focused on the polysaccharides group, though there are some other potentially bioactive compounds such as polyphenols, terpenoids, fucoxanthin, fatty acids and their derivatives, typical polar lipids, and other groups. Information on the modulation mechanism of Sargassum's bioactive compounds on the inflammatory response is also discussed here, but specific mechanisms related to the interaction between bioactive compounds and targets in cells still need to be further studied.

Production of Active Poly- and Oligosaccharidic Fractions from Ulva sp. by Combining Enzyme-Assisted Extraction (EAE) and Depolymerization

Data on fractionation and depolymerization of the matrix ulvan polysaccharides, and studies on the biological activities on skin cells, are very scarce. In this work, crude ulvans were produced by using EAE (enzyme-assisted extraction) and compared to maceration (an established procedure). After different fractionation procedures-ethanolic precipitation, dialysis, or ammonium sulfate precipitation-the biochemical composition showed that EAE led to an increased content in ulvans. Coupling EAE to sulfate ammonium precipitation led to protein enrichment. Oligosaccharides were obtained by using radical depolymerization by H₂O₂ and ion-exchange resin depolymerization. Sulfate groups were partially cleaved during these chemical treatments. The potential bioactivity of the fractions was assessed using a lipoxygenase inhibition assay for anti-inflammatory activity and a WST-1 assay for human dermal fibroblast viability and proliferation. All ulvans extracts, poly- and oligosaccharidic fractions from EAE, expanded the fibroblast proliferation rate up to 62%. Our research emphasizes the potential use of poly- and oligosaccharidic fractions of Ulva sp. for further development in cosmetic applications.

In vitro protective activity of South Australian marine sponge and macroalgae extracts against amyloid beta (Aβ1-42) induced neurotoxicity in PC-12 cells

South Australia is a biodiversity hotspot of marine sponges and macroalgae. This study aimed to evaluate the potential neuroprotective activity of extracts from these two marine sources by reducing the toxicity of human amyloid beta Aβ_1-42 in a cell model assay using PC-12 cells. A total of 92 extracts (43, 13, 16, and 20 extracts from sponge of 8 orders and 17 families, green algae of 3 orders and 4 families, brown algae of 6 orders and 8 families, and red algae of 5 orders and 10 families, respectively) were initially screened at three different concentrations (0.25, 2.5 and 25 μg/mL) to evaluate their toxicity using the MTT assay. About half of these extracts (26, 6, 5, and 10 extracts from sponge, green algae, brown algae, and red algae, respectively) showed some cytotoxicity, and were hence excluded from further assays. The rest of extracts (45 extracts in total) at 0.25 and 25 μg/mL were subsequently screened in a neuroprotection assay against Aβ_1-42 cytotoxicity. A cell viability reduction of 30% was observed in the MTT assay when the cells were treated with 1 μM Aβ_1-42. 29 extracts (13, 4, 7, and 5 extracts from sponge, green algae, brown algae, and red algae, respectively) reduced the toxicity induced by Aβ_1-42 (P < 0.05), indicating neuroprotective activity. These results demonstrate that marine sponge and macroalgae form a broad spectrum are promising sources of neuroprotective compounds against the hallmark neurotoxic protein in Alzheimer's disease (AD).

Commercial bovine proteoglycan is highly arthritogenic and can be used as an alternative antigen source for PGIA model

Rheumatoid arthritis (RA) is the most common systemic autoimmune disease. It affects mainly the joints, causing synovitis, cartilage destruction, and bone erosion. Many experimental models are used to study the mechanisms involved in immunopathogenesis and new therapies for this disease. Proteoglycan-induced arthritis (PGIA) is a widely used model based on the cross-reactivity of injected foreign (usually human) PG and mice self-PG. Considering the complexity of the extraction and purification of human PG, in this study we evaluated the arthritogenicity of bovine PG that is commercially available. Bovine PG was highly arthritogenic, triggering 100% incidence of arthritis in female BALB/c retired breeder mice. Animals immunized with bovine PG presented clinical symptoms and histopathological features similar to human RA and other experimental models. Moreover, bovine PG immunization determined higher levels of proinflammatory and anti-inflammatory cytokines in arthritic mice compared to healthy ones. As expected, only the arthritic group produced IgG1 and IgG2a antibodies against PG. Thus, commercial bovine PG can be used as an alternative antigenic source to PGIA for the study of many RA aspects, including the immunopathogenesis of the disease and also the development of new therapies.