Astragalus alcohol soluble polysaccharide (AASP) could present superior water solubility and antitumor activity with high concentration. Selenium nanoparticles (SeNPs) have received growing attention in various fields, but their unstable property increases the application difficulties. In the present study, functionalized nano-composites (AASP−SeNPs) were synthesized through SeNPs using AASP (average molecular weight of 2.1 × 10³ Da) as a surface modifier, and the preliminary structural characteristics and inhibitory mechanism on liver cancer (HepG2) cells were investigated. Results showed that AASP−SeNPs prepared under a sodium selenite/AASP mass ratio of 1/20 (w/w) were uniformly spherical with a mean grain size of 49.80 nm and exhibited superior dispersivity and stability in water solution. Moreover, the composites could dose-dependently inhibit HepG2 cell proliferation and induce apoptosis through effectively regulating mitochondria-relevant indicators including ΔΨm depletion stimulation, intracellular ROS accumulation, Bax/Bcl-2 ratio improvement, and Cytochrome c liberation promotion. These results provide scientific references for future applications in functional food and drug industries.

Ethanol fractional precipitation can initially separate polysaccharides according to the structure, which exhibits strong correlation with the biological activities. This study aimed to investigate the impact of varying ethanol concentrations on the structural characteristics, and the antitumor and antioxidant activities of polysaccharides derived from Dendrobium officinale through ethanol fractional precipitation, as well as their internal relationships. The polysaccharides acquired by absolute alcohol additions at a final liquor-ethanol volume ratio of 1:1, 1:2, and 1:4 were named DOP-1, DOP-2, and DOP-4, and the supernatant was named DOP-S. The results of the structural analysis revealed that the increase in ethanol concentrations resulted in a reduction in the molecular weights and the acetylation degree of the polysaccharides, as well as a decrease in mannose content and an increase in glucose content. In vitro experiments demonstrated that DOP-S exhibited optimal antitumor and antioxidant activities. Animal experiments further confirmed that DOP-S suppressed the growth of solid tumors significantly, enhanced lymphocytes, mediated immune ability, and improved the activity of antioxidant enzymes. These findings would establish a theoretical foundation and provide technical support for further advances and applications of polysaccharides derived from D. officinale in the fields of food and medicine.

Codonopsis pilosula polysaccharide (CPP) and rare element selenium (Se) have been proved to exert various biological activities, and our previous study demonstrated that selenium nanoparticles modified with CPP (CPP-SeNPs) possessed significantly enhanced tumor cytotoxicity in vitro. This study aimed to investigated the inhibitory effects of CPP-SeNPs complex on H22 solid tumors via immune enhancement. In this study, the H22 tumor-bearing mice model was constructed, and the potential mechanisms of CPP-SeNPs antitumor effects were further explored by evaluating cytokines expression levels, immune cells activities and tumor cells apoptotic indicators in each group. The results demonstrated that CPP-SeNPs effectively exerted dose-dependent protective effects on the immune organs of tumor-bearing mice in vivo, leading to increase in peripheral white blood cell counts and inhibition of solid tumor growth with inhibitory rate of 47.18% in high-dose group (1.5 mg/kg). Furthermore, CPP-SeNPs treatment significantly elevated the levels of TNF-α, IFN-γ, and IL-2 in mice sera, enhanced NK cell cytotoxicity, augmented macrophage phagocytosis capacity, as well as increased both the amounts and proliferation activity of lymphocyte subsets. CPP-SeNPs improved the immune system’s ability to clear tumor cells by up-regulating Bax expression while down-regulating Bcl-2 expression within solid tumors, indicating the potential activation of mitochondrial apoptosis pathway. Therefore, CPP-SeNPs administration can effectively inhibit tumor growth by enhancing immune response in tumor-bearing mice, which might be relevant to the regulation of gut microbiota short-chain fatty acids metabolisms. These findings could provide theoretical support and data foundation for further development of CPP-SeNPs as functional food and drug adjuvants.

Thymopentin (TP5) has exhibited strong antitumor and immunomodulatory effects in vivo. However, the polypeptide is rapidly degraded by protease and aminopeptidase within a minute at the N-terminal of TP5, resulting in severe limitations for further practical applications. In this study, the protective effects of water-soluble alginic acid (WSAA) on the N-terminal of TP5 were investigated by establishing an H22 tumor-bearing mice model and determining thymus, spleen, and liver indices, immune cells activities, TNF-α, IFN-γ, IL-2, and IL-4 levels, and cell cycle distributions. The results demonstrated that WSAA+TP5 groups exhibited the obvious advantages of the individual treatments and showed superior antitumor effects on H22 tumor-bearing mice by effectively protecting the immune organs, activating CD4⁺ T cells and CD19⁺ B cells, and promoting immune-related cytokines secretions, finally resulting in the high apoptotic rates of H22 cells through arresting them in S phase. These data suggest that WSAA could effectively protect the N-terminal of TP5, thereby improving its antitumor and immunoregulatory activities, which indicates that WSAA has the potential to be applied in patients bearing cancer or immune deficiency diseases as a novel immunologic adjuvant.

Background:Dendrobium officinale glycolipids (DOG), often left as residues after hot water extraction for polysaccharide production, are often discarded. Methods: This study investigates the optimal extraction of DOG using response surface methodology, focusing on liquid–solid ratios, ethanol concentrations, extraction temperatures, and extraction times, while preliminarily analyzing DOG’s structural properties. Additionally, the differences in antioxidant effects between DOG and ascorbic acid based on intestinal flora metabolism were further evaluated. Results: The optimal parameters for DOG extraction were determined as follows: liquid–solid ratio of 20 mL/g, ethanol concentration of 70%, extraction temperature of 70 °C, and extraction time of 2.5 h, yielding 2.64 ± 0.18%. In addition, DOG was identified as a diglyceride, mainly composed of glucose, mannose, linoleic acid, 9,12,15-octadecatrienoic acid, and presented certain direct free radicals scavenging effects. In animal experiments, unlike the direct free scavenging effects of ascorbic acid, DOG increased intestinal Bacteroides acidifaciens abundance in mice, up-regulated piceatannol expression, and down-regulated 1-naphthol expression, which contributed to antioxidant effects by enhancing the activities of SOD and GSH-Px while reducing MDA content. Conclusions: DOG was a diglyceride isolated from D. officinale residues after hot water extraction, and presented strong antioxidant effects by regulating intestinal flora metabolism. These findings could promote the efficient utilization of D. officinale and support further development of DOG in functional food applications.