Some Aspects of Investigation of the Central Mechanism of Antinociceptive Effect of a New Analgetic from the Hexaazaisowurtzitane Group.

Possible involvement of µ1- and κ-opioid receptors and cannabinoid type 1 receptors (CB1) into the mechanism of analgesic activity of the experimental drug product "Thiowurtzine, (capsule 120 mg)" synthesized on the basis of active pharmaceutical substance 4-(3,4-dibromthiophencarbonyl)-2,6,8,12-tetraacethyl-2,4,6,8,10,12hexaazatetracyclo [5,5,0,03,11,05,9]dodecane was studied in vivo using the hot plate test and acetic acid writhing test. The involvement of κ-opioid receptors and noninvolvement of µ1-receptors and CB1 receptors in the mechanism of thiowurtzine analgesia were demonstrated. The mechanism of interaction of the test analgesic with opioid receptors differs from that of the reference drug tramadol. The interaction of thiowurtzine with serotonergic, GABAergic, and muscarinic cholinergic neurotransmitter systems was studied in vivo using pharmacological analyzers. The absence of muscarinic cholinolytic effect of thiowurtzine was demonstrated in the model of arecoline-induced tremor. The central serotonin-blocking activity of the analgesic was revealed in the model of 5-hydroxytryptophan hyperkinesis in mice. Anticonvulsant activity was demonstrated in the corazol convulsions test, which attested to the presence of a GABAergic component. The mechanism of central analgesia caused by the drug product "Thiowurtzine, capsule 120 mg" appeared to be polymodal. The antinociceptive activity of the analgesic was comparable to that of tramadol.

Pharmacokinetics of a New Analgesic on the Basis of Hexaazaisowurtzitane Derivative.

We studied pharmacokinetics of a new analgesic based on a hexaazaisowurtzitane derivative (thiowurtzine, TWZ). A method for measuring TWZ in organs and tissues by HPLC/MS/MS was developed and validated. The sensitivity of the method under conditions of intragastric administration of TWZ to rats in a dose of 100 mg/kg is 0.5 ng/ml (calibration curve 0.5-400 ng/ml). The concentrations of the substance (Cmax) in the plasma, organs, and tissues of animals were 20-100 ng/ml, the time to reach the maximum concentration after a single dose (Tmax) was 2 h. The mean retention time of the substance in the body ranged from 5.67 to 17.15 h after administration. The highest concentrations were found in excretory organs (liver and kidneys), the substance also actively penetrated into muscle tissue. The medium concentrations were found in the brain and adipose tissue. The tropism to the heart tissues was minimal.

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.

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.

Analgesic Activity of Hexaazaisowurtzitane Derivatives.

Pronounced analgesic activity of the innovative compound 4-(3,4-dibromthiophencarbonyl)-2,6,8,12-tetraacethyl-2,4,6,8,10,12hexaazatetracyclo[5,5,0,03, 11,05, 9] dodecane (thiowurtzine) was observed in the thermal nociceptive hot plate test and in the acute visceral and somatic deep pain model (acetic acid writhing test). In these experimental models, naloxone-sensitive thiowurtzine-induced analgesia was revealed. The absence of tropism to peripheral opioid receptors in the acetic acid writhing test was demonstrated using naloxone methiodide. Course administration of low-toxic thiowurtzine in effective doses was not associated with ulcerogenic damage to the gastric mucosa in experimental animals.

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.

Anti-Inflammatory and Analgesic Activities of the Complex of Flavonoids from Lychnis chalcedonica L.

Anti-inflammatory and analgesic activities of the complex of flavonoids from Lychnis chalcedonica L. were studied in the models of acute aseptic inflammation induced by carrageenan, histamine, and serotonin and acetic acid-induced painful chemical stimulation. It is demonstrated that course treatment with flavonoids derived from Lychnis chalcedonica L. produced a stable pharmacological effect comparable with that of the reference anti-inflammatory drug diclofenac.

Plant Polysaccharides Attenuate Fluorouracil Toxicity for the Small Intestinal Epithelium.

Polysaccharides from Tussilago farfara L., Acorus calamus L., and Echinacea purpurea (L.) Moench attenuated the toxic effect of fl uorouracil on the small intestinal epithelium of mice with Lewis lung carcinoma. Addition of polysaccharides to chemotherapy protocols stimulated reparative regeneration processes in the small intestine damaged by the cytostatic treatment. No stimulating effects of the polysaccharides on tumor growth and metastasizing were revealed.

Effects of nonstarch polysaccharides with different molecular weights on the development of Lewis lung carcinoma in mice and efficiency of cytostatic therapy.

The effects of nonstarch polysaccharides with different molecular weights on the development of Lewis' lung carcinoma and efficiency of cyclophosphamide therapy in mice were studied. Treatment with these substances with low molecular weights (<30 kDa) caused no changes in the primary tumor growth, but inhibited its metastasizing, while nonstarch polysaccharides with high molecular weights (>400 kDa) inhibited the growth of Lewis' lung carcinoma node. Antimetastatic effects of cyclophosphamide were stimulated by low and high molecular weight polysaccharides.

[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.

Comparative evaluation of the efficiency of various alginate forms under conditions of an oncological experiment.

The effects of various alginate forms on the development of transplanted tumors in mice and efficiency of cytostatic therapy were studied. High-molecular-weight Ca and Na alginates, acid-soluble hydrolysate, and sodium alginate fraction inhibited the growth of Ehrlich adenocarcinoma. The use of acid-insoluble sodium alginate in chemotherapy protocol improved the treatment efficiency. All alginate forms inhibited metastasizing of Lewis pulmonary carcinoma; in combination with cyclophosphamide they potentiated its antimetastatic effect.

[Effect of ginsenoside Rh2 on the development of transferred tumors and chemotherapy efficiency].

Experiments on C57B1/6 mice showed that ginsenoside Rh2 inhibited the growth and metastasis process of Lewis lung tumor and increased the antitumor and antimetastatic effects of cyclophosphamide. On the model of transferred melanoma B-16, ginsenoside Rh2 showed a tendency to increase the antiblastome effect of the cytostatic drug.

[Anti-ulcerative effect of non-starch polysaccharides].

Standard models of experimental ulceration (of neurogenic origin, H. Shay ulcer, indomethacine-, ethanol-, prednisolone-, histamine- and acetate-induced ulcers) were used to demonstrate protective effect of non-starch polysaccharides (potassium alginate, potassium pectate, low-esterified pectin). Potassium pectate proved to be the most efficacious protector. Mechanism of its anti-ulcerative action is attributable to antacidic, cytoprotective, and reparative activity. It appeals to optimally stimulate the motor-evacuation function and, besides, exhibits marked anti-inflammatory activity.

[Antiulcer effect of calcium pectate on model of chronic gastric ulcer in rats].

Calcium pectate has been found to exhibit an antiulcer activity in rats with model of chronic ulcers. Course treatment of the experimental animals with calcium pectate (i) accelerated the repair of experimental damage due to better integrity and higher secretory activity of epithelium and (ii) decreased hemodynamic disorders in surrounding mucous and epithelial membranes. The maximum effect, which was achieved with calcium pectate in a dose of 50 mg/kg, exceeded the action of the reference drug maalox on both 14th and 21st days of experiment.

[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.

[Experimental evaluation of the antiulcer activity of calcium pectate].

Both chronic (prophylactic) and single administration of standardized calcium pectate considerably increased the resistance of rat stomach mucous membrane with respect to ulcerogenic factors of various etiology, including immobilized stress, indomethacin, ethanol, prednizolone, and histamine, according to H. Shay's model. The gastroprotective effect of this polysaccharide was comparable with or exceeded the action of famotidine, sea buckthorn oil, and maalox.

Gastroprotective effect of nonstarch polysaccharide calcium pectate under experimental conditions.

Course prophylactic administration and single therapeutic treatment with calcium pectate improved resistance of rat gastroduodenal mucosa to ethanol-induced ulcers, prednisolone-induced ulcers, and H. Shay ulceration of the gastric mucosa.