Targeting mTOR Signaling by Dietary Polysaccharides in Cancer Prevention: Advances and Challenges

Advances and perspectives on isolation, structural characterization, structure-property relationships, and pharmacological mechanisms of tumor immune glucans: A review

Tumor immune glucans (TIGs) are emerging as promising anticancer agents capable of enhancing immune responses and mitigating the side effects of chemotherapy. This review analyzes 59 TIGs published between 2015 and 2025, focusing on their isolation, structural characterization, structure-activity relationships, and pharmacological mechanisms. Literature searches were conducted in databases such as Web of Science, PubMed, Google Scholar, Embase, Cochrane Library, ClinicalTrials.gov and CNKI using keywords including "glucans", "tumor immunity", and "polysaccharide structure," covering studies in both English and Chinese. The review highlights the relationship between the structural features of TIGs and their antitumor activities.1,3-linked β-glucans surpassed 1,4-linked or 1,6-linked configurations in antitumor immunostimulatory activity. Elevated molecular weight enhances the structural robustness of TIGs chains, facilitating their selective recognition by cellular receptors and amplifying their anti-tumor immune responses. TIGs exert antitumor effects through mechanisms such as immunomodulation, inhibition of tumor immune escape, and remodeling of the tumor microenvironment, involving signaling pathways such as TLRs/NF-κB, JAK/STAT, MAPK, Bax/Bcl-2, PI3K/Akt, and VEGF/VEGFR. Despite their promising therapeutic potential, challenges remain, including incomplete structural characterization, insufficient IC50 value data, and a lack of reference drugs. Many studies focus on cytokine levels and cellular activity, but deeper molecular mechanistic insights are needed. Further research into the mechanisms of action and targets of TIGs may pave the way for new cancer treatment strategies.

Facile preparation of iridium-based AIE polymer dots for sensitive electrochemiluminescence immunoassay of CD44 protein

The development of aggregation-induced emission (AIE) luminophores is a fascinating and promising topic in electrochemiluminescence (ECL) bioanalysis. Herein, the AIE-active but water-insoluble [Ir(bt)₂(acac)] (bt = 2-phenylbenzothiazole, acac = acetylacetonate) was encapsulated within poly(styrene-maleic anhydride) (PSMA) using a simple nanoprecipitation method. This encapsulation strategy could effectively limit the free motion of Ir(bt)₂(acac) and trigger the aggregation-induced electrochemiluminescence (AIECL) effect. The water dispersibility and ECL intensity of Ir(bt)₂(acac)-polymer dots (IrPdots) were greatly improved compared to equivalent amounts of Ir(bt)₂(acac) alone. More importantly, unlike Ir(bt)₂(acac), the IrPdots possess carboxyl groups, allowing them to be conjugated with biomolecules for bioanalytical applications. Consequently, a sandwich ECL immunosensor for the sensitive detection of CD44 was constructed using the prepared IrPdots-labeled detection antibody (Ab2) as the ECL probe and polyaniline nanorods (PANI NRs) as the substrate that provided a large electroactive surface for immobilizing capture antibody (Ab1). Under optimized experimental conditions, a good linear relationship was observed between the logarithm of ECL intensity and the CD44 concentration, ranging from 0.1 pg/mL to 50 ng/mL, with a detection limit as low as 77 fg/mL. This work introduces a method for the preparation of Pdots containing AIE-active cyclometallated iridium complexes, potentially broadening the application of these water-insoluble but highly AIE-active iridium complexes in aqueous bioassays.

New insights into signaling pathways of cancer prevention effects of polysaccharides from edible and medicinal mushrooms

BACKGROUND

Despite extensive efforts, empirical techniques have yielded limited progress in finding effective anticancer medications, with chemotherapy drugs often associated with drug resistance and serious side effects. Thus, there is a pressing need for novel agents with minimal adverse effects. Natural substances, widely used in treating various illnesses, including cancer, offer promising alternatives. Among these, mushrooms, rich in low molecular weight secondary metabolites, polysaccharides, and polysaccharide-protein complexes, have gained attention for their potential anticancer properties.

RESULTS

Mushroom polysaccharides have been found to impede oncogenesis and tumor metastasis by directly inhibiting tumor cell growth and indirectly enhancing immune system functions. These polysaccharides engage with numerous cell signaling pathways that influence cancer development and progression. They affect pathways that control cell survival, growth, and differentiation, and they also play a role in adjusting the tumor immune microenvironment.

CONCLUSION

This review highlights the potential of mushroom polysaccharides as promising anticancer agents due to their ability to modulate cell signaling pathways crucial for cancer development. Understanding the mechanisms underlying their effects on these pathways is essential for harnessing their therapeutic potential and developing novel strategies for cancer treatment.

Antitumor activity of Polygonatum sibiricum polysaccharides

Cancer is a global public health problem. Natural polysaccharides have been shown to enhance the effectiveness of cancer treatments. Polygonatum sibiricum (PS) has been used for millennia to treat diverse diseases. PS comprises numerous active constituents, including saponins, peptides, volatile oils, polysaccharides, and lectins. Many studies have highlighted the crucial role of polysaccharides in PS. Modern studies have shown that Polygonatum sibiricum polysaccharide (PSP) exhibits diverse pharmacological activities, including immunomodulatory, antitumor, antioxidant, and anti-aging effects. However, further study of the antitumor mechanisms is difficult because the activities of PSP are closely associated with its complex structural features and the different molecular weights of its components. Therefore, this review focuses on the research background and the extraction and purification of PSP. Studies related to the mechanism of the antitumor effects of PSP constituents of different molecular weights are also summarized, and perspectives on PSP research are presented.

A review of the fungal polysaccharides as natural biopolymers: Current applications and future perspective

As a unique natural resource, fungi are a sustainable source of lipids, polysaccharides, vitamins, proteins, and other nutrients. As a result, they have beneficial medicinal and nutritional properties. Polysaccharides are among the most significant bioactive components found in fungi. Increasing research has revealed that fungal polysaccharides (FPS) contain a variety of bioactivities, including antitumor, antioxidant, immunomodulatory, anti-inflammatory, hepatoprotective, cardioprotective, and anti-aging properties. However, the exact knowledge about FPS and their applications related to their future possibilities must be thoroughly examined to enhance a better understanding of this sustainable biopolymer source. Therefore, FPS' biological applications and their role in the food and feed industry, agriculture, and cosmetics applications were all discussed in this work. In addition, this review highlighted the mode of action of FPS on human diseases by regulating gut microbiota and discussed the mechanism of FPS as antioxidants in the living cell. The structure-activity connections of FPS were also highlighted and explored. Moreover, future perspectives were listed to pave the way for future studies of FPS applications. Hence, this study can be a scientific foundation for future FPS research and industrial applications.

Impacts of preparation technologies on biological activities of edible mushroom polysaccharides - novel insights for personalized nutrition achievement

Edible mushroom polysaccharides (EMPs) as a natural macromolecular carbohydrate have a very complex structure and composition. EMPs are considered ideal candidates for developing healthy products and functional foods and have received significant research attention due to their unique physiological activities such as immunomodulatory, anti-inflammatory, anti-tumor/cancer, gut microbiota regulation, metabolism improvement, and nervous system protection. The structure and monosaccharide composition of edible mushroom polysaccharides have an unknown relationship with their functional activity, which has not been widely studied. Therefore, we summarized the preparation techniques of EMPs and discussed the association between functional activity, preparation methods, structure and composition of EMPs, laying a theoretical foundation for the personalized nutritional achievements of EMP. We also establish the foundation for the further investigation and application of EMPs as novel functional foods and healthy products.

Extraction, structures, biological effects and potential mechanisms of Momordica charantia polysaccharides: A review

Momordica charantia L. is a kind of vegetable with medicinal value. As the main component of the vegetable, Momordica charantia polysaccharides (MCPs) mainly consist of galactose, galacturonic acid, xylose, rhamnose, mannose and the molecular weight range is 4.33 × 103-1.16 × 106 Da. MCPs have been found to have various biological activities in recent years, such as anti-oxidation, anti-diabetes, anti-brain injury, anti-obesity, immunomodulatory and anti-inflammation. In this review, we systematically summarized the extraction methods, structural characteristics and physicochemical properties of MCPs. Especially MCPs modulate gut microbiota and cause the alterations of metabolic products, which can regulate different signaling pathways and target gene expressions to exert various functions. Meanwhile, the potential structure-activity relationships of MCPs were analyzed to provide a scientific basis for better development or modification of MCPs. Future researches on MCPs should focus on industrial extraction and molecular mechanisms. In East Asia, Momordica charantia L. is used as both food and medicine. It is not clear whether MCP has its unique biological effects. Further study on the difference between MCPs and other food-derived polysaccharides will be helpful to the development and potential application of Momordica charantia L.

Recent innovations (2020-2023) in the approaches for the chemical functionalization of curdlan and pullulan: A mini-review

Chemical modification represents a highly efficacious approach for enhancing the physicochemical characteristics and biological functionalities of natural polysaccharides. However, not all polysaccharides have considerable pharmacologic activity; so, appropriate chemical modification strategies can be selected in accordance with the distinct structural properties of polysaccharides to aid in improving and encouraging the presentation of their biological activities. Hence, there has been a growing interest in the chemical alteration of polysaccharides due to their various properties such as antioxidant, anticoagulant, antiviral, anticancer, biomedical, antibacterial, and immunomodulatory effects. This paper offers a comprehensive examination of recent scientific advancements produced over the past four years in the realm of unique chemical and functional modifications in curdlan and pullulan structures. This review aims to provide readers with an overview of the structural activity correlations observed in the backbone structures of curdlan and pullulan, as well as the diverse chemical modification processes employed for these polysaccharides. Additionally, the review aims to examine the effects of combining various bioactive molecules with chemically modified curdlan and pullulan and explore their potential applications in various important fields.

Functional Perspective of Leeks: Active Components, Health Benefits and Action Mechanisms

Leek (Allium fistulosum L.), a common and widely used food ingredient, is a traditional medicine used in Asia to treat a variety of diseases. Leeks contain a variety of bioactive substances, including sulfur compounds, dietary fiber, steroid compounds and flavonoid compounds. Many studies have shown that these active ingredients produce the following effects: promotion of blood circulation, lowering of cholesterol, relief of fatigue, anti-inflammation, anti-bacteria, regulation of cell metabolism, anti-cancer, anti-oxidation, and the lowering of fat and blood sugar levels. In this paper, the main bioactive components and biological functions of leeks were systemically reviewed, and the action mechanisms of bioactive components were discussed. As a common food, the health benefits of leeks are not well known, and there is no systematic summary of leek investigations. In light of this, it is valuable to review the recent progress and provide reference to investigators in the field, which will promote future applications and investigations of leeks.