Fucoidan extracted from Fucus evanescens brown algae corrects immunity and hemostasis disorders in experimental endotoxemia

Fucoidan improving spinal cord injury recovery: Modulating microenvironment and promoting remyelination

INTRODUCTION

Excessive neuroinflammation, apoptosis, glial scar, and demyelination triggered by spinal cord injury (SCI) are major obstacles to SCI repair. Fucoidan, a natural marine plant extract, possesses broad-spectrum anti-inflammatory and immunomodulatory effects and is regarded as a potential therapeutic for various diseases, including neurological disorders. However, its role in SCI has not been investigated.

METHODS

In this study, we established an SCI model in mice and intervened in injury repair by daily intraperitoneal injections of different doses of fucoidan (10 and 20 mg/kg). Concurrently, primary oligodendrocyte precursor cells (OPCs) were treated in vitro to validate the differentiation-promoting effect of fucoidan on OPCs. Basso Mouse Scale (BMS), Louisville Swim Scale (LSS), and Rotarod test were carried out to measure the functional recovery. Immunofluorescence staining, and transmission electron microscopy (TEM) were performed to assess the neuroinflammation, apoptosis, glial scar, and remyelination. Western blot analysis was conducted to clarify the underlying mechanism of remyelination.

RESULTS

Our results indicate that in the SCI model, fucoidan exhibits significant anti-inflammatory effects and promotes the transformation of pro-inflammatory M1-type microglia/macrophages into anti-inflammatory M2-type ones. Fucoidan enhances the survival of neurons and axons in the injury area and improves remyelination. Additionally, fucoidan promotes OPCs differentiation into mature oligodendrocytes by activating the PI3K/AKT/mTOR pathway.

CONCLUSION

Fucoidan improves SCI repair by modulating the microenvironment and promoting remyelination.

Fucoidan Ameliorates Oxidative Stress, Inflammation, DNA Damage, and Hepatorenal Injuries in Diabetic Rats Intoxicated with Aflatoxin B1

The current study was carried out to evaluate the ameliorative effect of fucoidan against aflatoxicosis-induced hepatorenal toxicity in streptozotocin-induced diabetic rats. Sixty-four Wister albino male rats were randomly assigned into eight groups (8 rats each) that received normal saline, fucoidan (FUC) at 100 mg/kg/day orally for 4 weeks, streptozotocin (STZ) at 50 mg/kg/i.p. single dose, STZ plus FUC, aflatoxin B₁ (AFB₁) at 50 μg/kg/i.p. after one month of the beginning of the experiment for 2 weeks, AFB₁ plus FUC, STZ plus AFB₁, or STZ plus AFB₁ and FUC. Injection of rats with STZ induced hyperglycemia. Rats with STZ-induced diabetes, with or without AFB₁ intoxication, had significantly elevated activities of serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase, and levels of serum urea, creatinine, cholesterol, 8-oxo-2′-deoxyguanosine, interleukin-1β, interleukin-6, and tumor necrosis factor-α. In addition, these rats exhibited increased lipid peroxidation and reduced glutathione concentration and activities of superoxide dismutase, catalase, and glutathione peroxidase enzymes in the hepatic and renal tissues. In contrast, administration of FUC to diabetic rats, with or without AFB₁ intoxication, ameliorated the altered serum parameters, reduced oxidative stress, DNA damage, and inflammatory biomarkers, and enhanced the antioxidant defense system in the hepatic and renal tissues. These results indicated that FUC ameliorated diabetes and AFB₁-induced hepatorenal injuries through alleviating oxidative stress, DNA damage, and inflammation.

The Pharmacokinetics of Fucoidan after Topical Application to Rats

Fucoidan, a fucose-rich polysaccharide from brown algae, has been used for transdermal formulations targeting inflammatory skin conditions, for the treatment of thrombosis, vascular permeability diseases, subcutaneous wounds, and burns. However, the pharmacokinetics of fucoidan after topical application has not been described. In this study, an ointment (OF) containing 15% fucoidan was topically applied to rats at the doses of 50–150 mg/g. The anti-Xa activity was selected as the biomarker, and the amidolytic assay method was validated and applied for pharmacokinetic studies of fucoidan. Fucoidan in OF penetrated the skin and distributed into the skin, striated muscle, and plasma with AUC_0–48 = 0.94 μg·h/g, 2.22 μg·h/g, and 1.92 µg·h/mL, respectively. The longest half-life for fucoidan was observed in plasma, then in striated muscle and skin. It was found that the pharmacokinetics of fucoidan after topical OF application was linear, in the range of 50–150 mg/kg. No accumulation of fucoidan in plasma was observed after repeated topical applications of 100 mg/kg during five days. Our results support the rationality of topical application of formulations with fucoidan.

Phycochemical Constituents and Biological Activities of Fucus spp

Seaweeds are known to be a good supply of key nutrients including carbohydrates, protein, minerals, polyunsaturated lipids, as well as several other health-promoting compounds capable of acting on a wide spectrum of disorders and/or diseases. While these marine macroalgae are deeply rooted in the East Asian culture and dietary habits, their major application in Western countries has been in the phycocolloid industry. This scenario has however been gradually changing, since seaweed consumption is becoming more common worldwide. Among the numerous edible seaweeds, members of the genus Fucus have a high nutritional value and are considered good sources of dietary fibers and minerals, especially iodine. Additionally, their wealth of bioactive compounds such as fucoidan, phlorotannins, fucoxanthin and others make them strong candidates for multiple therapeutic applications (e.g., antioxidant, anti-inflammatory, anti-tumor, anti-obesity, anti-coagulant, anti-diabetes and others). This review presents an overview of the nutritional and phytochemical composition of Fucus spp., and their claimed biological activities, as well as the beneficial effects associated to their consumption. Furthermore, the use of Fucus seaweeds and/or their components as functional ingredients for formulation of novel and enhanced foods is also discussed.

Antibacterial properties of a glycolipid-rich extract and active principle from Nunavik collections of the macroalgae Fucus evanescens C. Agardh (Fucaceae)

This study investigated the antibacterial activity of glycolipid-rich extracts of the brown macroalga Fucus evanescens in cell culture. Accessions were collected on the Arctic coast of Ungava Bay, Nunavik, Quebec. The crude ethyl acetate extract of these accessions showed strong antibacterial activity (≥4 log(10) cfu) against Hemophilus influenzae , Legionella pneumophila , Propionibacterium acnes (ATCC and clinical isolate), and Streptococcus pyogenes at 100 µg/mL. This algal extract inhibited by 3 log(10) Clostridium difficile and methicillin-resistant Staphylococcus aureus , whereas Bacillus cereus , Escherichia coli , Klebsiella pneumoniae , and Pseudomonas aeruginosa were not significantly affected. Further investigations of the activity of a glycolipid-rich fraction, extracted with dichloromethane, against Propionibacterium acnes showed an MIC(100) of 50 µg/mL, with an inhibition of more than 99% at only 7.8 µg/mL. The main active compound, a β-d-galactosyl O-linked glycolipid, was synthesized for the bioassay and showed an MIC(100) of 50 µg/mL but lost its activity more quickly with only 50% of inhibition at 12.5 µg/mL. Therefore, the semipurified F. evanescens extract could be a good choice for future research into the development of alternative treatments for acne therapy.

Effect of fucoidan on aspirin-induced stomach ulceration in rats

In this study, the effects of fucoidan on aspirin-induced ulcers in rats were evaluated: both biochemical and immunological parameters were taken into consideration. The status of stomach tissue glycogen storage and histological changes were also examined. Examination of basic biochemical parameters showed significant (p<0.01) alterations in aspartate (AST) and alanine (ALT) transaminases in ulcer-induced rats. Also, moderate alterations (p<0.05) were observed in the levels of cholesterol and blood urea nitrogen (BUN). Histopathological examination showed neutrophil infiltration and inflammation in oxyntic cells with altered glycogen storage. Analysis of serum cytokines of aspirin-induced rats showed a moderate decrease in interleukin-10 (IL-10) with considerable increase of interleukin-6 (IL-6) and interferon-gamma (INF-gamma) when compared with control. Administration of fucoidan showed considerable (p<0.05) protection against ulceration by inhibiting the acute alterations of AST, ALT, cytokines and stomach glycogen. However, aggravated serum INF-gamma was observed in the fucoidan-pretreated group. These findings suggest that the anti-ulcer property of fucoidan might contribute in protecting the inflammatory cytokine-mediated oxidative damage to gastric mucosa.