Sulfated polysaccharide from Undaria pinnatifida stabilizes the atherosclerotic plaque via enhancing the dominance of the stabilizing components

A Comparative Analysis of the Anti-Tumor Activity of Sixteen Polysaccharide Fractions from Three Large Brown Seaweed, Sargassum horneri, Scytosiphon lomentaria, and Undaria pinnatifida

Searching for natural products with anti-tumor activity is an important aspect of cancer research. Seaweed polysaccharides from brown seaweed have shown promising anti-tumor activity; however, their structure, composition, and biological activity vary considerably, depending on many factors. In this study, 16 polysaccharide fractions were extracted and purified from three large brown seaweed species (Sargassum horneri, Scytosiphon lomentaria, and Undaria pinnatifida). The chemical composition analysis revealed that the polysaccharide fractions have varying molecular weights ranging from 8.889 to 729.67 kDa, and sulfate contents ranging from 0.50% to 10.77%. Additionally, they exhibit different monosaccharide compositions and secondary structures. Subsequently, their anti-tumor activity was compared against five tumor cell lines (A549, B16, HeLa, HepG2, and SH-SY5Y). The results showed that different fractions exhibited distinct anti-tumor properties against tumor cells. Flow cytometry and cytoplasmic fluorescence staining (Hoechst/AO staining) further confirmed that these effective fractions significantly induce tumor cell apoptosis without cytotoxicity. qRT-RCR results demonstrated that the polysaccharide fractions up-regulated the expression of Caspase-3, Caspase-8, Caspase-9, and Bax while down-regulating the expression of Bcl-2 and CDK-2. This study comprehensively compared the anti-tumor activity of polysaccharide fractions from large brown seaweed, providing valuable insights into the potent combinations of brown seaweed polysaccharides as anti-tumor agents.

Bioactive polysaccharides and their potential health benefits in reducing the risks of atherosclerosis: A review

Atherosclerosis is a kind of lipid-driven chronic inflammatory disease of arteries and is the principal pathological basis of life-threatening cardiovascular disease events, such as strokes and heart attacks. Clinically, statins are the most commonly prescribed drugs for the treatment of atherosclerosis, but prolonged use of these drugs exhibit many adverse reactions and have limited efficacy. Polysaccharides are important natural biomacromolecules widely existing in plants, animals, microorganisms and algae. They have drawn considerable attention worldwide due to their multiple healthy functions, along with their non-toxic property. Importantly, a growing number of studies have demonstrated that bioactive polysaccharides exhibit prominent efficiency in controlling atherosclerotic risk factors like hyperlipemia, hypertension, oxidative stress, and inflammation. In recent decades, various bioactive polysaccharides with different structural features and anti-atherosclerotic potential from natural sources have been isolated, purified, and characterized. The aim of this review is to focus on the research progress of natural polysaccharides in reducing the risks of atherosclerosis based on evidence of in vitro and in vivo studies from 1966 to 2022. PRACTICAL APPLICATIONS: In the future, it is still necessary to strengthen the research on the development and mechanism of polysaccharides with anti-atherosclerotic potential. These anti-atherosclerotic polysaccharides with different structural characteristics and physiochemical properties from different sources will constitute a huge source of materials for future applications, especially in functional foods and drugs. The information summarized here may serve as useful reference materials for further investigation, production, and application of these polysaccharides in functional foods and therapeutic agents.

Recent research advances in polysaccharides from Undaria pinnatifida: Isolation, structures, bioactivities, and applications

Undaria pinnatifida, one of the most widespread seafood consumed in China and many other nations, has been traditionally utilized as an effective therapeutically active substance for edema, phlegm elimination and diuresis, and detumescence for more than 2000 years. Numerous studies have found that polysaccharides of U. pinnatifida play an indispensable role in the nutritional and medicinal value. The water extraction and alcohol precipitation method are the most used method. More than 40 U. pinnatifida polysaccharides (UPPs) were successfully isolated and purified from U. pinnatifida, whereas only few of them were well characterized. Pharmacological studies have shown that UPPs have high-order structural features and multiple biological activities, including anti-tumor, antidiabetic, immunomodulatory, antiviral, anti-inflammatory, antioxidant, anticoagulating, antithrombosis, antihypertension, antibacterial, and renoprotection. In addition, the structural characteristics of UPPs are closely related to their biological activity. In this review, the extraction and purification methods, structural characteristics, biological activities, clinical settings, toxicities, structure-activity relationships and industrial application of UPPs are comprehensively summarized. The structural characteristics and biological activities as well as the underlying molecular mechanisms of UPPs were also outlined. Furthermore, the clinical settings and structure-activity functions of UPPs were highlighted. Some research perspectives and challenges in the study of UPPs were also proposed.

In Vitro and In Vivo Dendritic Cell Immune Stimulation Effect of Low Molecular Weight Fucoidan from New Zealand Undaria pinnatifida

Low molecular weight fucoidan (LMWF) has been reported to have immunomodulation effects through the increase of the activation and function of macrophages. In this study, the regulating effect of LMWF from Undaria pinnatifida grown in New Zealand on dendritic cells (DCs) was investigated. We discovered that LMWF could stimulate DCs' maturation and migration, as well as CD4+ and CD8+ T cells' proliferation in vitro. We proved that this immune promoting activity is activated through TLR4 and its downstream MAPK and NF-κB signaling pathways. Further in vivo (mouse model) investigation showed that LMWF has a strong immunological boosting effect, such as facilitating the proliferation of immune cells and increasing the index of immune organs. These findings suggest that LMWF has a positive immunomodulatory effect and is a promising candidate to supplement cancer immunotherapy.

Extraction, purification and characterization of sulphated polysaccharide from Bellamya quadrata and its stabilization roles on atherosclerotic plaque

The aim of this paper was to investigate the extraction, purification and characterization of sulphated polysaccharide (BQPS) from Bellamya quadrata and its stabilization roles on atherosclerotic plaque. Firstly, crude polysaccharide (CBQP) from Bellamya quadrata was extracted by protease enzyme assisted extraction. Moreover, its optimal parameters were obtained by the response surface method as follows: the ratio of water to raw material of 24:1, enzyme dosage of 285 U/g, enzymolysis pH value of 4.7 and temperature of 67 °C. Secondly, CBQP was further purified to obtain the target polysaccharide BQPS by Q Sepharose Fast Flow and Sephacryl S-400 gel column chromatography. Then, the characterization of BQPS revealed that it possessed a total polysaccharide content of 91.88 ± 1.23%, sulfuric acid group content of 9.12 ± 1.59% and molecular weight of 91.1 kDa. BQPS was only consisted of glucose without any proteins. Finally, BQPS was confirmed to have a significant stabilizing effect on atherosclerotic plaque and its mechanism was related to the selective promotion of autophagy with the precisely right strength.