Effects of Ethanol Concentrations on Primary Structural and Bioactive Characteristics of Dendrobium officinale Polysaccharides.

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.

Structural analysis of Salvia miltiorrhiza polysaccharide and its regulatory functions on T cells subsets in tumor-bearing mice combined with thymopentin.

Salvia miltiorrhiza ethanol-extracted polysaccharide (SMEP) and thymopentin (TP5) have been proved with strong immunomodulatory activity, and T cells subsets play pivotal roles in the inhibition of solid tumors growth. In the present study, the structure of SMEP was further identified via methylation and nuclear magnetic resonance spectra, and the immunomodulatory activity in combination with TP5 was investigated via evaluating T cell subsets spatial distributions in tumor-bearing mice, finally the cellular status of solid tumor cells was analyzed. The results revealed that SMEP was a neutral heteropolysaccharide using (1 â†’ 4)-α-D-Glcp and (2 â†’ 1)-ß-D-Fruf as the main chain, along with branched chains of (1 â†’ 6)-α-D-Galp. The SMEP+TP5 treatments could effectively promote the differentiation and improve the specific recognition capacity of CD4+ T cells in tumor-bearing mice, thereby activate tumor-infiltrating CD8+ T cells to exert cytotoxic effects, finally promoting the tumor cells apoptosis via blocking cell cycle at G0/G1 phase, which might be relevant with suppression of Wnt/ß-catenin signaling pathway. These findings highlighted the potential of SMEP as an immunoadjuvant for patients bearing immune-deficiency related diseases, and provided data support for the functional researches of T cell subsets in tumor immunity.

Structural characteristics and anti-tumor activity of alcohol-precipitated polysaccharides from Cordyceps militaris under different ethanol concentrations.

Six Cordyceps militaris polysaccharides (named CMP-1, CMP-2, CMP-3, CMP-4, CMP-9, and CMP-A) were obtained by fractional alcohol precipitation. The experimental results showed that the six Cordyceps militaris polysaccharides had similar chemical composition and spectral features, and different molecular weights, monosaccharide compositions and anti-tumor activities. Purification of CMP-9 yielded the small molecule polysaccharide LMW-CMP (3.06 kDa). Structural experiments showed that LMW-CMP is an α-glucan with (1 â†’ 4)-α-D-Glcp as the main chain and a glucose branched chain attached at the O-6 position. The results of cell experiments showed that LMW-CMP could effectively inhibit the growth and proliferation of HepG2 cells, activate the downstream NF-κB signaling pathway through the MAPK pathway to induce apoptosis of HepG2 cells, and block apoptosis at the G1 phase. Animal experiments showed that LMW-CMP inhibited the proliferation of tumor cells in H22 tumor-bearing mice by improving the state of immune organs, increasing the activity of immune cells and cytokine levels in the body, and regulating the distribution of lymphocyte subpopulations, with a tumor inhibition rate of 45.70 % (200 mg/kg).

Selenochemical modification of low molecular weight polysaccharides from Grifola frondosa and the mechanism of their inhibitory effects on gastric cancer cells.

An important micronutrient involved in immune response and antitumor is selenium. LMW-GFP, a polysaccharide extracted from Grifola frondosa seed bodies, has a relatively weak antitumor effect on BGC-823 and MFC cells in vitro, whereas selenium binding to LMW-GFP can significantly increase the in vitro antitumor activity of LMW-GFP. In this study, Se-LMW-GFP was prepared by the HNO3-Na2SeO3 method, and the structures of LMW-GFP and Se-LMW-GFP were characterized by UV-visible spectroscopy of absorption, FTIR spectroscopy, and electron scanning microscopy, and these structural analyses showed that selenium was successfully complexed to LMW-GFP. The selenium content of Se-LMW-GFP was measured to be 2.08 % ± 0.08 % by ICP-MS. The anti-tumor activity of LMW-GFP before and after selenium modification was compared by cellular experiments, and the findings indicated that the anti-tumor activity of Se-LMW-GFP was considerably improved over that of LMW-GFP, and inhibited the proliferation of BGC-823 cells and MFC cells through a combination of the Fas/FasL-mediated exogenous death receptor pathway as well as the endogenous mitochondrial pathway. Our results suggest that Se-LMW-GFP not only has great potential for natural health food and anti-gastric cancer drug development but is also a good selenium supplement.