The Level of Anti-Polyethylene Glycol (PEG) Immunoglobulin G Antibodies in Human Serum Does Not Correlate with Efficiency of PEGylated Nanoparticle Uptake by Monocytes.

The presence of anti-polyethylene glycol (PEG) antibodies can limit the clinical efficacy of PEGylated drugs and cause anaphylactic reactions in patients. Monocytes/macrophages are effector cells involved in IgG-mediated passive systemic anaphylaxis. We studied the influence of human blood serum on the efficiency of uptake of PEGylated nanoparticles by human blood monocytes. It has been shown that magnetic nanoparticles modified with PEG-3000 and solid lipid nanoparticles containing PEG-2000 are avidly internalized by human blood monocytes in vitro, the uptake efficiency depends on the features (composition) of donor blood serum, but does not correlate with the level of the IgG antibody against PEG.

Hypolypidemic Activity of L-Rhamnopyranosyl-6-O-Methyl-D-Galacturonan, a Polysaccharide Isolated from Birch Leaves (Betula pendula L.).

In male Syrian hamsters fed a synthetic high-fat diet enriched with cholesterol (0.3%), administration of a polysaccharide from birch leaves L-rhamnopyranosyl-6-O-methyl-D-galacturonan (3 g/100 g of diet) resulted in a decrease in total cholesterol levels, mainly due to the LDL fraction, triglycerides, and bile acids in blood serum; the content of triglycerides and cholesterol in the liver also decreased, while excretion of bile acids with feces increased. Thus, the lipid-lowering effect of L-rhamnopyranosyl-6-O-methyl-D-galacturonan is related to its ability to bind bile acids in the intestine and interrupt their enterohepatic circulation.

The Influence of Water-Soluble Polysaccharides of Crataegus sanguinea Pall. on Nitric Oxide Production by Macrophages.

The in vitro addition of water-soluble polysaccharides isolated from the leaves of Crataegus sanguinea Pall. to culture of mouse peritoneal macrophages induced classical activation of antigen-presenting cells by increasing NO synthase activity and reducing arginase expression.

Effects of Tussilago farfara L. Polysaccharides on the Expression of PD-1 (CD279) and PD-L1 (CD274) in Peripheral Blood and Tumor Tissue Lymphocytes in Mice with Lewis Lung Carcinoma.

One of prospective methods for immunotherapy of tumors is modulation via immunological checkpoints, specifically, via the PD-1(CD279)/PD-L1(CD274) system. Interactions between tumor cell receptor (CD279) and the ligand on lymphocytes (CD274) leads to lymphocyte inactivation, which allows tumor escape from the immune control. Experiments on C57BL/6 mice with Lewis lung carcinoma demonstrate the possibility of reducing the expression of CD279 and CD274 on the peripheral blood and tumor tissue lymphocytes under the effects of Tussilago farfara L. polysaccharides. This phenomenon can underlie the antitumor and antimetastatic effects of these substances.

Study of Immunotropic Properties of Water-Soluble Polysaccharides Isolated from Conium maculatum Grass.

Addition of water-soluble polysaccharides isolated from Conium maculatum L. to the mouse peritoneal macrophage culture induces classical activation of antigen-presenting cells due to an increase in NO synthase activity and a decrease in arginase expression.

Effect of Tussilago farfara L. Polysaccharides on the Content of Hematopoietic Stem Cells (CD117+34+) in the Bone Marrow of Mice Treated with Cyclophosphamide.

Myelotoxicity is a serious side effect of anticancer drugs. The search for drugs that can reduce the hematological complications of chemotherapy through modulation of hematopoietic stem cells is an urgent task of oncopharmacology. In the present study we showed that administration of Tussilago farfara L. polysaccharides to C57BL/6 mice treated with cyclophosphamide can increase the number of hematopoietic stem cells (CD117+34+) in the bone marrow.

Correction of Damaging Effects of Cisplatin-Containing Polychemotherapy on the Intestinal Epithelium with Tussilago farfara L. Polysaccharides.

A possibility for correction of damaging effects of polychemotherapy on the intestinal epithelium with Tussilago farfara L. polysaccharides was studied on C57Bl/6 mice with Lewis lung carcinoma. The polysaccharides had protective and/or stimulating effects on the intestinal epithelium during polychemotherapy and promoted reparative regeneration in the intestine.

Protective Effect of Polysaccharides from Tussilago farfara L. on Bone Marrow Cells and Small Intestinal Epithelium Under Conditions of Polychemotherapy Evaluated by DNA Comet Assay.

Using DNA comet assay we found that polysaccharides from Tussilago farfara L. reduced the intensity of polychemotherapy-induced apoptosis and DNA damage in bone marrow cells and small intestinal epithelium of C57Bl/6 mice, which attested to genoprotective properties of these polysaccharides.

Modification of the Myelotoxic and Antitumor Effects of Polychemotherapy by Polysaccharides from Tussilago farfara L.

The experiments on C57Bl/6 mice with Lewis lung carcinoma showed that addition of Tussilago farfara L. polysaccharides to conventional cisplatin/paclitaxel polychemotherapy moderated neutropenia caused by antitumor therapy and increased its efficiency. The stimulating effect of polysaccharides on the granulopoietic lineage cells is comparable with that of recombinant CSF Neupogen.

Effect of Acorus calamus L. Polysaccharide on CD274 and CD326 Expression by Lewis Lung Carcinoma Cells in Mice.

Tumor cells can maintain their growth via immunosuppression and escape from host antitumor immunity by controlling the PD-1/PD-L1 system. Expression of PD-L1 (CD274) is an inhibitory signal for T cells, while the increase in CD326 expression in the tumor tissue correlates with metastasis development. The experimental preparation on the basis of α(1,2)-L-rhamno-α(1,4)-D-galactopyranosyluronan from Acorus calamus L. produces an antitumor effect: it reduces tumor node size and the number and area of metastases after transplantation of Lewis lung carcinoma. Using flow cytometry, we demonstrated a decrease in the population of tumor cells expressing surface CD274 (PD-L1) and CD326 antigens after 20-day course of α(1,2)-L-rhamno-α(1,4)-D-galactopyranosyluronan.

[Prospects for the use of plant polysaccharides in complex treatment of malignant tumors].

The pharmacological properties of plant polysaccharides are reviewed and original experimental data on the properties of water-soluble polysaccharides isolated from Acorus calamus L. are presented. The possibility of using plant (in particular, Acorus calamus) polysaccharides to increase the effectiveness of anticancer treatment of transferred tumors and to reduce the toxic effects of cytostatic treatment on the normal cells of blood, liver, and epithelium of thin intestine in experimental animals has been demonstrated.

[Mutagen properties of water-soluble polysaccharides from Acorus calamus].

Mutagenic properties of water soluble polysaccharides (WSPS) extracted from Acorus calamus L. have been studied. Neither a single intravenous injection nor a course intraperitoneal introduction of WSPS in a dose of 1/2 LD50 to mice of the CBA/CaLac line increases the level of cytogenetic disorders in the bone marrow cells. The investigation of WSPS by means of the somatic mosaicism test showed that the given dose of WSPS does not increase the rate of mutant spots on Drosophila wings.

[Effect of plant polysaccharides on TH1-dependent immune response: screening investigation].

We have studied the influence of water-soluble polysaccharides isolated from Tussilago farfara L. leaves, Betula verrucosa Ehrh. leaves, Calendula officinalis L. flowers, Acorus calamus rhizomes, Inula helenium L. rhizomes, overground part of Trifolium pretense L., and overground part ofArtemisia absinthium L., on Thl immune response induced by sheep red blood cells and on NO production by murine peritoneal macrophages in vitro. All the investigated polysaccharides have stimulated a Th1 response. Polysaccharides isolated from Betula verrucosa leaves did not influence NO synthesis, while polysaccharides of Tussilago farfara leaves and Acorus calamus rhizomes stimulated NO synthase of murine macrophages on a level comparable with that of lipopolysaccharides (LPS). Polysaccharides from Inula helenium rhizomes, Calendula officinalis flowers, and overground parts of Trifolium pretense and Artemisia absinthium also stimulated NO production, but to a lower extent in comparison to LPS.

[Effect of Echinacea purpurea tincture and its polysaccharide complex on the efficacy of cytostatic therapy of transferred tumors].

Experiments on C57LB/6 mice with transplanted Luis lung carcinoma showed that the officinal Echinacea purpurea preparation did not influence the efficacy of cytostatic therapy. This echinacea preparation did not change the development of metastases and even stimulated the tumor growth. In contrast, a hydrophilic polysaccharide complex isolated from echinacea increased the antitumor and antimetastatic activity of cyclophosphamide.