Antiviral potential of plant polysaccharide nanoparticles actuating non-specific immunity

"Processing-structure-activity" relationships of polysaccharides in Chinese Materia Medica: A comprehensive review

Recently, the effects of Chinese material medica processing (CMMP) on physicochemical properties and biological activities of polysaccharides have been a prominent research topic. Previous studies have primarily concentrated on individual processing methods, structural characteristics, or biological activities, overlooking the interrelationships among these factors. This review systematically summarizes how various processing methods influence the structural characteristics of polysaccharides, including molecular weight, monosaccharide composition, glycosidic linkages, and the content of neutral sugar and uronic acid. We explored the impacts of these structures on biological activities, specifically the regulation of anti-inflammatory, antioxidant, and immunomodulating effects of polysaccharides. The chemical mechanism of polysaccharides changes during CMMP is also discussed. Different processing methods result in distinct structural variations of polysaccharides, which in turn significantly affect their physicochemical properties and health functions. Therefore, a comprehensive understanding of the processing-structure-activity relationships of polysaccharides is crucial to realizing polysaccharide preparations with targeted functional effects. We hope these findings not only provide novel strategies for clinical applications involving polysaccharides but also provide a reference basis for the research on improving the CMMP mechanism.

Preparation, structural characterization, and bioactivities of polysaccharides from Rhodiola: A review

Rhodiola, the dried rhizome of various plants of the family Crassulaceae and genus Rhodiola, has been used as a traditional Tibetan medicine for thousands of years, with high medicinal and healthcare value. Polysaccharides, the major active components of Rhodiola, have attracted widespread attention due to their abundant biological activities and medicinal value. Rhodiola polysaccharides (RPs) have various biological activities such as germ cell protection, antioxidant, immunomodulatory, anti-fatigue, hypoglycemic, anti-tumor, and hematopoietic functions. The biological activities of RPs are closely related to their structures and different extraction and purification methods produce different polysaccharide structures. This review aims to provide a comprehensive overview of the research progress in the extraction, purification, structural characterization, bioactivity, potential mechanisms, and structural modification of RPs as well as their potential development prospects and future promising research directions, to lay a foundation for the further development of RP pharmaceutical products.

Anti-virus activity and mechanisms of natural polysaccharides from medicinal herbs

There has been a sudden increase in viral diseases, such as coronavirus disease 2019 (COVID-19), causing significant harm to human and animal well-being, as well as economic development. Medicinal herbs, with a history of thousands of years in clinical use, contain versatile polysaccharides as one of their primary compounds. This review offers an overview of the antiviral effects of polysaccharides from medicinal herbs on viruses in humans, poultry, swine and aquaculture in recent years. The mechanism of these antiviral polysaccharides, involved in hindering various stages of the viral life cycle thereby blocking virus infection, is summarized. The review also explores other underlying mechanisms of antiviral effects, such as enhancing the immune response, regulating inflammatory reactions, balancing gut flora, reducing oxidative stress, and suppressing apoptosis through various corresponding signaling pathways. The structure-function relationships discussed in this article also aid in understanding the antiviral mechanism of natural polysaccharides, indicating the need for more in-depth research and analysis. Natural polysaccharides from medicinal herbs have emerged as valuable resources in the fight against viral infections, exhibiting high effectiveness. This review emphasizes the promising role of polysaccharides from medicinal herbs as potential candidates for blocking viral infections in humans and animals.

Refined polysaccharide from Dendrobium devonianum resists H1N1 influenza viral infection in mice by activating immunity through the TLR4/MyD88/NF-κB pathway

Dendrobium polysaccharide exhibits multiple biological activities, such as immune regulation, antioxidation, and antitumor. However, its resistance to viral infection by stimulating immunity is rarely reported. In this study, we explored the effect and mechanism of DVP-1, a novel polysaccharide from Dendrobium devonianum, in the activation of immunity. After being activated by DVP-1, the ability of mice to prevent H1N1 influenza virus infection was investigated. Results of immune regulation showed that DVP-1 significantly improved the immune organ index, lymphocyte proliferation, and mRNA expression level of cytokines, such as IL-1β, IL-4, IL-6, and TNF-α in the spleen. Immunohistochemical results showed that DVP-1 obviously promoted the mucosal immunity in the jejunum tissue. In addition, the expression levels of TLR4, MyD88, and TRAF6 and the phosphorylation levels of TAK1, Erk, JNK, and NF-κB in the spleen were upregulated by DVP-1. The virus infection results showed that the weight loss of mice slowed down, the survival rate increased, the organ index of the lung reduced, and the virus content in the lung decreased after DVP-1 activated immunity. By activating immunity with DVP-1, the production of inflammatory cells and inflammatory factors in BALF, and alveolar as well as peribronchiolar inflammation could be prevented. The results manifested that DVP-1 could resist H1N1 influenza virus infection by activating immunity through the TLR4/MyD88/NF-κB pathway.

The anti-atherosclerotic effects of natural polysaccharides: from phenomena to the main mechanisms of action

Polysaccharides (PSs) of plant origin have a variety of biological activities, anti-atherosclerotic including, but their use in atherosclerosis therapy is hindered by insufficient knowledge on the cellular and molecular mechanisms of action. In this review, the influence of several natural PSs on the function of macrophages, viral activity, and macrophage cholesterol metabolism has been discussed considering the tight interplay between these aspects in the pathogenesis of atherosclerosis. The anti-atherosclerotic activities of natural PSs related to other mechanisms have been also explored. Directions for further research of anti-atherosclerotic effects of natural PSs have been outlined, the most promising of which can be nutrigenomic studies.