Novel pyridyl-substituted nitronyl nitroxides as potential antiarrhythmic and hypotensive agents with low toxicity and enhanced stability in aqueous solutions

This study explores the antiarrhythmic and hypotensive potential of pyridyl-substituted nitronyl nitroxides derivatives, uncovering the crucial role of a single carbon moiety of the pyridine cycle alongside radical and charged oxygen centers of the imidazoline fragment. Notably, the introduction of fluorine atoms diminished the antiarrhythmic effect, while the most potent derivatives featured the nitronyl nitroxide pattern positioned at the third site of the pyridine cycle. Gender-dependent responses were observed in lead compounds LCF3 and LMe, with LMe inducing temporary bradycardia and hypotension specifically in female rats, and LCF3 causing significant blood pressure reduction followed by rebound in females compared to milder effects in males. Mechanistic insights point towards β1 adrenoceptor blockade as an underlying mechanism, supported by experiments on isolated rat atria. This research underscores the interplay between structure, cardiovascular effects and gender-specific responses, offering insights for therapeutic strategies for treating free radical-associated cardiovascular disorders.

Hydrophilic Reduction-Resistant Spin Labels of Pyrrolidine and Pyrroline Series from 3,4-Bis-hydroxymethyl-2,2,5,5-tetraethylpyrrolidine-1-oxyl

Highly resistant to reduction nitroxides open new opportunities for structural studies of biological macromolecules in their native environment inside living cells and for functional imaging of pH and thiols, enzymatic activity and redox status in living animals. 3,4-Disubstituted nitroxides of 2,2,5,5-tetraethylpyrrolidine and pyrroline series with a functional group for binding to biomolecules and a polar moiety for higher solubility in water and for more rigid attachment via additional coordination to polar sites were designed and synthesized. The EPR spectra, lipophilicities, kinetics of the reduction in ascorbate-containing systems and the decay rates in liver homogenates were measured. The EPR spectra of all 3,4-disubstituted pyrrolidine nitroxides showed additional large splitting on methylene hydrogens of the ethyl groups, while the spectra of similar pyrroline nitroxides were represented with a simple triplet with narrow lines and hyperfine structure of the nitrogen manifolds resolved in oxygen-free conditions. Both pyrrolidine and pyrroline nitroxides demonstrated low rates of reduction with ascorbate, pyrrolidines being a bit more stable than similar pyrrolines. The decay of positively charged nitroxides in the rat liver homogenate was faster than that of neutral and negatively charged radicals, with lipophilicity, rate of reduction with ascorbate and the ring type playing minor role. The EPR spectra of N,N-dimethyl-3,4-bis-(aminomethyl)-2,2,5,5-tetraethylpyrrolidine-1-oxyl showed dependence on pH with pKa = 3, ΔaN = 0.055 mT and ΔaH = 0.075 mT.

Global LC-MS/MS targeted metabolomics using a combination of HILIC and RP LC separation modes on an organic monolithic column based on 1-vinyl-1,2,4-triazole

The paper presents an LC-MS/MS-based approach to targeted screening of both polar and non-polar metabolites using a synthesized monolithic column which is a copolymer of styrene, divinylbenzene, and 1-vinyl-1,2,4-triazole. It was shown that this column in combination with eluents 20 mM (NH4)2CO3 + NH3 (pH = 9.8, eluent A) and ACN (eluent B) allows for separation of metabolites of different nature in two modes, HILIC and RP LC, and these methods are mutually complementary. A combination of analyses based on these two modes was proposed, allowing detection of about 400 metabolites in a total time of less than 30 min. Comparison of the developed method with those utilizing commercially available columns with sorbents of various types showed that it could provide a broader metabolite coverage. Using the developed approach, metabolomic screening of dried blood spots samples of mice exposed with X-ray was performed, and metabolites that could be considered as possible markers of irradiation exposure and organ tissue damage were detected. Analysis of marker metabolites revealed metabolic pathways that were altered by radiation exposure. Comparison of the results with literature data showed the effectiveness of the developed metabolomic screening approach.

Curcumin and Its Supramolecular Complex with Disodium Glycyrrhizinate as Potential Drugs for the Liver Fluke Infection Caused by Opisthorchis felineus

Opisthorchiosis is a parasitic liver disease found in mammals that is widespread throughout the world and causes systemic inflammation. Praziquantel remains the drug of choice for the treatment of opisthorchiosis, despite its many adverse effects. An anthelmintic effect is attributed to the main curcuminoid of Curcuma longa L. roots-curcumin (Cur)-along with many other therapeutic properties. To overcome the poor solubility of curcumin in water, a micellar complex of curcumin with the disodium salt of glycyrrhizic acid (Cur:Na₂GA, molar ratio 1:1) was prepared via solid-phase mechanical processing. In vitro experiments revealed a noticeable immobilizing effect of curcumin and of Cur:Na₂GA on mature and juvenile Opisthorchis felineus individuals. In vivo experiments showed that curcumin (50 mg/kg) had an anthelmintic effect after 30 days of administration to O. felineus-infected hamsters, but the effect was weaker than that of a single administration of praziquantel (400 mg/kg). Cur:Na₂GA (50 mg/kg, 30 days), which contains less free curcumin, did not exert this action. The complex, just as free curcumin or better, activated the expression of bile acid synthesis genes (Cyp7A1, Fxr, and Rxra), which was suppressed by O. felineus infection and by praziquantel. Curcumin reduced the rate of inflammatory infiltration, whereas Cur:Na₂GA reduced periductal fibrosis. Immunohistochemically, a decrease in liver inflammation markers was found, which is determined by calculating the numbers of tumor-necrosis-factor-positive cells during the curcumin treatment and of kynurenine-3-monooxygenase-positive cells during the Cur:Na₂GA treatment. A biochemical blood test revealed a normalizing effect of Cur:Na₂GA (comparable to that of curcumin) on lipid metabolism. We believe that the further development and investigation of therapeutics based on curcuminoids in relation Opisthorchis felineus and other trematode infections will be useful for clinical practice and veterinary medicine.

Bornyl-Containing Derivatives of Benzyloxyphenylpropanoic Acid as FFAR1 Agonists: In Vitro and In Vivo Studies

Type 2 diabetes mellitus (T2DM) is one of the most common chronic diseases worldwide. Several classes of hypoglycemic drugs are used to treat it, but various side effects limit their clinical use. Consequently, the search for new anti-diabetic agents remains an urgent task for modern pharmacology. In this investigation, we examined the hypoglycemic effects of bornyl-containing benzyloxyphenylpropanoic acid derivatives (QS-528 and QS-619) in a diet-induced model of T2DM. Animals were given the tested compounds per os at a dose of 30 mg/kg for 4 weeks. At the end of the experiment, compound QS-619 demonstrated a hypoglycemic effect, while QS-528 showed hepatoprotection. In addition, we performed a number of in vitro and in vivo experiments to study the presumed mechanism of action of the tested agents. Compound QS-619 was determined to activate the free fatty acid receptor-1 (FFAR1) similarly to the reference agonist GW9508 and its structural analogue QS-528. Both agents also increased insulin and glucose-dependent insulinotropic polypeptide concentrations in CD-1 mice. Our results indicate that QS-619 and QS-528 are probably full FFAR1 agonists.

Synthesis and Evaluation of Hypoglycemic Activity of Structural Isomers of ((Benzyloxy)phenyl)propanoic Acid Bearing an Aminobornyl Moiety

Free fatty acid receptor-1 (FFAR1) agonists are promising candidates for therapy of type 2 diabetes because of their ability to normalize blood sugar levels during hyperglycemia without the risk of hypoglycemia. Previously, we synthesized compound QS-528, a FFA1 receptor agonist with a hypoglycemic effect in C57BL/6NCrl mice. In the present work, structural analogs of QS-528 based on (hydroxyphenyl)propanoic acid bearing a bornyl fragment in its structure were synthesized. The seven novel compounds synthesized were structural isomers of compound QS-528, varying the positions of the substituents in the aromatic fragments as well as the configuration of the asymmetric center in the bornyl moiety. The studied compounds were shown to have the ability to activate FFAR1 at a concentration of 10 μM. The cytotoxicity of the compounds as well as their effect on glucose uptake in HepG2 cells were studied. The synthesized compounds were found to increase glucose uptake by cells and have no cytotoxic effect. Two compounds, based on the meta-substituted phenylpropanoic acid, 3-(3-(4-(((1R,2R,4R)-1,7,7-trimethylbicyclo-[2.2.1]heptan-2-ylamino)methyl)benzyloxy)phenyl)propanoic acid and 3-(3-(3-(((1R,2R,4R)-1,7,7-trimethylbicyclo [2.2.1]heptan-2-ylamino)methyl)benzyloxy)phenyl)propanoic acid, were shown to have a pronounced hypoglycemic effect in the oral glucose tolerance test with CD-1 mice.

Terpene-Containing Analogues of Glitazars as Potential Therapeutic Agents for Metabolic Syndrome

Metabolic syndrome is a complex of abnormalities involving impaired glucose and lipid metabolism, which needs effective pharmacotherapy. One way to reduce lipid and glucose levels associated with this pathology is the simultaneous activation of nuclear PPAR-alpha and gamma. For this purpose, we synthesized a number of potential agonists based on the pharmacophore fragment of glitazars with the inclusion of mono- or diterpenic moiety in the molecular structure. The study of their pharmacological activity in mice with obesity and type 2 diabetes mellitus (C57Bl/6^Ay) revealed one substance that was capable of reducing the triglyceride levels in the liver and adipose tissue of mice by enhancing their catabolism and expressing a hypoglycemic effect connected with the sensitization of mice tissue to insulin. It has also been shown to have no toxic effects on the liver.

Studies of the Specific Activity of Aerosolized Isoniazid against Tuberculosis in a Mouse Model

The aerosol inhalation delivery of isoniazid in mice was investigated, and the specific activity of the aerosol form of isoniazid was studied with the mouse model of tuberculosis infection, the M. tuberculosis H37Rv strain. Aerosol delivery was performed using a laminar-flow horizontal nucleation chamber. The inhalation dose was measured in real-time mode using a diffusion aerosol spectrometer. The mean particle diameter was 0.6 ± 0.03 μm, and the inhalation dose was 5–9 mg/kg. Pharmacokinetic measurements were carried out in nose-only and whole-body chambers. Isoniazid concentration in blood serum and its mass in the lungs were measured as a function of time using high-performance liquid chromatography. Studies of the specific activity of aerosolized isoniazid reveal that treatment with the aerosol lead to the complete recovery of the experimental tuberculosis infection as early as after 28 days after the start of inhalation treatment, while in the animals from the group receiving isoniazid per-orally, sole revivable tuberculosis mycobacteria were detected. Histologic examinations show that only a few macrophagal (nonspecific) granulomas without mycobacteria were detected in the spleen after per-oral and aerosol treatment, the number of granulomas on the 28th day being three times smaller in the latter case. The results show that the developed technique of isoniazid aerosol inhalation may have clinical potential.

Behavioral effects and inflammatory markers in the brain and periphery after repeated social defeat stress burdened by Opisthorchis felineus infection in mice

The combination of 4-week repeated social defeat stress (RSDS) and Opisthorchis felineus infection was modeled in C57BL/6 mice. Various parameters were compared between three experimental groups of male mice (SS: mice subjected to RSDS, OF: mice infected with O. felineus, and OF + SS: mice subjected to both adverse factors) and behavior-tested and intact (INT) controls. The combination caused liver hypertrophy and increased the blood level of proinflammatory cytokine interleukin 6 and proteolytic activity of cathepsin B in the hippocampus. Meanwhile, hypertrophy of the spleen and of adrenal glands was noticeable. Anxious behavior in the elevated plus-maze test was predominantly due to the infection, with synergistic effects of an interaction of the two adverse factors on multiple parameters in OF + SS mice. Depression-like behavior in the forced swimming test was caused only by RSDS and was equally pronounced in SS mice and OF + SS mice. Helminths attenuated the activities of cathepsin B in the liver and hypothalamus (which were high in SS mice) and increased cathepsin L activity in the liver. The highest blood level of corticosterone was seen in SS mice but was decreased to control levels by the trematode infection. OF mice had the lowest level of corticosterone, comparable to that in INT mice. Thus, the first data were obtained on the ability of O. felineus helminths-even at the immature stage-to modulate the effects of RSDS, thereby affecting functional connections of the host, namely "helminths → liver↔brain axis."

Aerosol inhalation delivery of cefazolin in mice: Pharmacokinetic measurements and antibacterial effect

Aerosol inhalation delivery of cefazolin, a broad-spectrum first-generation cephalosporin antibiotic, was investigated. Inhalation system based on ultrasonic nebulizer was developed for the generation of dry cefazolin aerosol within mean particle diameter range 0.5-3.0 μm and mass concentration 0.01-3 μg/cm³. Pharmacokinetic measurements were carried out for the aerosolized form of cefazolin delivered in mice using nose-only chamber. Cefazolin concentrations in blood serum and in the lungs of mice were measured as a function of time by means of high performance liquid chromatography. Body-delivered dose depending on particle size, concentration and inhalation time as well as other pharmacokinetic parameters were determined. The antibacterial effect of aerosolized cefazolin was assessed through the aerosol inhalation treatment of mice infected with Klebsiella pneumoniae. Survival rate for infected mice after the treatment with cefazolin aerosol demonstrated high antibacterial efficiency of the inhalation delivery of cefazolin in comparison with intraperitoneal delivery.

Prostatotropic Action of Glycyrrhizic Acid Disodium Salt in Benign Prostatic Hyperplasia Models

The prostatotropic activity of glycyrrhizic acid disodium salt (Na₂GA) was studied in the models of benign prostatic hyperplasia (BPH) induced by chronic injection of sulpiride (40 mg/kg intraperitoneally for 8 weeks) or testosterone propionate (20 mg/kg subcutaneously for 4 weeks) in the Wistar rats. The oral administration of Na₂GA in a dose of 100 mg/kg produced a moderate antiproliferative effect in both BPH models resulting in reduced volume density of prostatic epithelium (in the testosterone model) and increased volume density of the glandular lumen (in both models). The observed prostatotropic effects of Na₂GA were similar to those of Permixon and finasteride, but they were less pronounced as confirmed by smaller drops in epithelial volume density and epithelial-to-stromal ratio compared to the effects of both reference drugs.

Morphological Assessment of Prostatotropic Activity of (3,5-Dimethyl-4-Hydroxy)Benzyl Thiododecane on a Model of Benign Prostatic Hyperplasia in Rats

Prostatotropic activity of (3,5-dimethyl-4-hydroxy)benzyl thiododecane (T-DD) was evaluated on a model of benign prostatic hyperplasia induced in Wistar rats by chronic (2 months) intraperitoneal administration of sulpiride (40 mg/kg). Morphometric analysis of the dorsolateral lobe of the prostate showed that after the 2-month course of intragastric T-DD (100 mg/kg) administered in parallel with sulpiride, the volume density of glandular epithelium decreased by 1.7 times, while the volume density of prostate stroma increased by 2 times. After administration of the reference drug Permixon at a dose of 50 mg/kg, the volume densities of epithelium decreased by 1.3 times and stromal volume density increased by 1.5 times. The observed effects are presumably related to suppression of 5α-reductase activity and modulation of estrogen receptors in the prostate.

Genotoxic activity of 1,2,3-triazolyl modified furocoumarins and 2,3-dihydrofurocoumarins

The furocoumarin backbone is a promising platform for chemical modifications aimed at creating new pharmaceutical agents. However, the high level of biological activity of furocoumarins is associated with a number of negative effects. For example, some of the naturally occurring ones and their derivatives can show genotoxic and mutagenic properties as a result of their forming crosslinks with DNA molecules. Therefore, a particularly important area for the chemical modification of natural furocoumarins is to reduce the negative aspects of their bioactivity. By studying a group of 21 compounds-1,2,3-triazolyl modified derivatives of furocoumarin and peucedanin-using the SOS chromotest, the Ames test, and DNA-comet assays, we revealed modifications that can neutralize the structure's genotoxic properties. Theoretical aspects of the interaction of the compound library were studied using molecular modeling and this identified the leading role of the polyaromatic molecular core that takes part in stacking-interactions with the pi-systems of the nitrogenous bases of DNA.

Physicochemical Properties and Anti-Opisthorchosis Effect of Mechanochemically Synthesized Solid Compositions of Praziquantel with Glycyrrhizic Acid Disodium Salt

The mechanochemical preparation of solid compositions of praziquantel with plant saponin (glycyrrhizic acid disodium salt) is described. The study of a number of physicochemical parameters showed that dissolving solid compositions in water is accompanied by the inclusion of praziquantel molecules into micelles, which are formed in the solution of the glycyrrhizic acid disodium salt. Using the opisthorchiasis model caused by Opisthorchis felineus, we found a 4- to 11-fold increase in the anthelmintic activity of praziquantel in the composition as compared to the official praziquantel. According to the pharmacokinetic data, the use of the composition increased the bioavailability of praziquantel 3 times.

Amide of Lambertian Acid Suppresses Hyperactivation of Inotropic Glutamate Receptors, but not Synaptic Potentiation in Hippocampal Sections

Amide of lambertian acid suppresses hyperactivation of inotropic glutamate receptors in hippocampal sections induced by a decrease in the level of magnesium ions (a selective blocker of glutamate NMDA receptors). Treatment of the sections with amide of lambertian acid in standard physiological saline does not prevent development of NMDA-dependent synaptic potentiation. Lambertian acid isolated from needles and turpentine of Siberian pine (Pinus sibirica R. Mayr), and its derivatives may become a source of substances with glutamatergic mechanism of action for treatment of cognitive and neurodegenerative disorders.

Specific Features of Progression of the Parasitic Invasion, caused by Opisthorchis felineus, in Golden Hamsters

The influence of Opisthorchis felineus invasion on the development of pathological changes in the hepatobiliary system was studied in 120 golden hamsters in a long-term experiment (42 weeks) after single infection per os in the dose of 50 metacercariae per animal. The animals were sacrificed on weeks 4, 8, 12, 16, 28 and 42. Chronic experimental infestation with O. felineus triggered a cascade of morphogenetic processes in both extrahepatic and intrahepatic biliary systems. At the early stages of the experiment, polyps and strictures of bile ducts were formed in the lobar bile ducts; in portal tracts, hyperplasia and adenomatous transformation of the newly formed epithelial structures were observed. At the later stages, third-degree biliary intraepithelial neoplasia developed in the lobar bile ducts; in the intrahepatic bile ducts, increased epitheliocyte hyperplasia and invasive growth of cell cords were observed, that impaired tissue architectonics. Progressing cell atypia can be classified as cholangiocellular cancer.

11-Phenylundeca-5Z,9Z-dienoic Acid: Stereoselective Synthesis and Dual Topoisomerase I/IIα Inhibition

(5Z,9Z)-11-Phenylundeca-5,9-dienoic acid was stereoselectively synthesized, based on original cross-cyclomagnesiation of 2-(hepta-5,6-dien-1-yloxy)tetrahydro-2H-pyran and buta-2,3-dien-1-ylbenzene with EtMgBr in the presence of the Cp2TiCl2 catalyst giving 2,5-dialkylydenemagnesacyclopentane in 86% yield. The acid hydrolysis of the product and Jones oxidation of the resulting 2-{[(5Z,9Z)-11-phenylundeca-5,9-dien-1-yl]oxy}tetrahydro-2Н-pyran afforded (5Z,9Z)-11-phenylundeca-5,9-dienoic acid in an overall yield of 75%. A high inhibitory activity of the synthesized acid with respect to human topoisomerase I (hTop1) and II (hTop2α) was detected. Resorting to the data of molecular docking, a mechanism of inhibition was proposed.

Combined effects of social stress and liver fluke infection in a mouse model

The effects of two influences, social stress and acute opisthorchiasis, were investigated in inbred C57BL/6J male mice. In the model of social stress, mice were repeatedly attacked and defeated by aggressive outbred ICR male mice and were in continuous sensory contact with an aggressive conspecific mouse in their home cage for 20 days. Acute opisthorchiasis was provoked by invasion of Opisthorchis felineus (50 larvae per animal) on the fourth day after the social stress was induced. Simultaneous action of both factors caused the hypertrophy of adrenal glands, as well as elevated the activity of cathepsins B and L in the spleen. This effect on the activity of the cysteine proteases in the hippocampus and hypothalamus following O. felineus invasion was the predominant result of simultaneous action with social stress. Acute opisthorchiasis, social stress, and their combination caused an increase in the level of blood IL-6 in approximately 30% of the animals. Social stress induced a more pronounced effect on mouse plus-maze behavior than O. felineus invasion. Our results suggest a more severe negative effect of the simultaneous influence of both factors on most of the parameters that were investigated.

[Synthesis of new analogues of combretastatin A-4 and the study of their anti-inflammatory activity]

New approach to synthesis of analogs of natural Combretastatin A-4 based on interaction of α-acetylenic ketones with secondary amines (diethyl amine, pyrrolidine, piperidine, morpholine) is offered. Unknown analogs of Combretastatin A-4 with β-aminovinylcarbonyl bridges are received earlier. Anti-inflammatory activity of the received connections is studied.

[Synthesis and Anti-Inflammatory activity of the propargylamino derivatives of naphthoquinonlevopimaric acid]

Modification of naphthoquinonlevopimaric acid was carried out by introducing of propargylamino residues. Anti-inflammatory activity Mannich bases were studied.

[Hepatoprotective activity of betulonic acid amides containing a piperidine or pyrrolidine nitroxide moiety]

Betulonic acid amides containing a nitroxyl radical moiety possess antiholestatic effects in mice. Introduction ofpiperidine nitroxide moiety into lupan core increases its hepatoprotective activity. Oral administration of piperidine nitroxide derivative in dose 50 mg/kg doesn't stimulate transplanted tumor growth and raises a lifespan of mice.

[Role of opisthorchis felineus on induction of bile duct cancer]

Opisthorchis felineus (Trematoda) is widespread in the Russian Federation, especially in Siberia, and other countries of Europe. Infestation of endemic area population with O. felineus reaches 80%. On animal models of the infection of closely related Opisthorchis viverrini combined with the nitrosamines' intake it has been shown that the parasite induces cholangiocarcinoma. However carcinogenic potential of O. felineus is still poorly studied. The present study is aimed to investigate the role of O. felineus in cholangiocarcinoma carcinogenesis in hamster treated additionally by dimethylnitrosamine (DMN). Golden hamsters were divided into 4 groups (15 specimens in the control group and 20 for other groups): (I) untreated control, (II) 12.5 ppm DMN solution intake, (III) infected with 50 metacercariae of O. felineus and (IV) infected with 50 metacercariae of O. felineus and 12.5 ppm DMN solution intake. According to the histological data, in the. O. felineus-infested group significant hyperplastic and dysplastic biliary changes were found considered as a precancerogenic state. Such pathological changes of bile ducts were more severe in group treated with both factors, with cholangiocarcinoma being found out at 18th week in all the animals of this group. These results demonstrate that O. felineus could play promoting role in two-step model in cholangiocarcinoma carcinogenesis and may be used to define the O.felineus group in the International Agency for Research on Cancer classification of agents, mixtures and exposures (IARC categories).

[Effects of buspirone complex with glycyrrhizic acid on behavior of mice with anxious-depressive state]

We report here studies of the effects of subchronic administration of 5-HT1A receptor agonist buspirone and its novel complex with glycyrrhizic acid (GA) to C57BL/6J mice at the different stages of the anxious-depressive state formation, induced by conditions of social stress. The experiment of agents' administration during the conditions of stress (beginning with initial stage) showed that only complex had a protective effect revealed in prevention of the anxiety with the high level of mice communicativeness maintenance. At the stage when the anxious-depressive state is completely formed, buspirone and its complex with GA decreased mice motor activity however complex--less significantly. Here we discuss a possible mechanism of action of investigated agents on the background of changes in the sensitivity of 5-HT1A receptors, induced by the formation of the anxious-depressive state of mice with experience of social stress. Despite of different effects of agents depending on the stage of the anxious-depressive state development, novel buspirone complex with GA has some advantage over buspirone.

[Synthesis of aminopropylaminoderivatives of betulinic and oleanolic acids]

On the basis of betulinic and oleanolic acids triterpenoids with different with different amine fragments: (3-aminopropoxy)-, 3-acetyl-(3-aminopropyl)amino-, 6-[bis(3-aminopropyl)amino]hexylamino-, (3-aminopropyl)-4-aminosulfonyl-4-phenylamino- at positions C3 and C28 were synthesized. It is shown that betulonic acid amide with 4,4'-diaminodiphenylsulfonic substituent don't render antitumor effect in mice with transplantable Lewis lung carcinoma, but possess significant anti-inflammatory activity.

Soluble chitosan-carrageenan polyelectrolyte complexes and their gastroprotective activity

The soluble polyelectrolyte complexes (PEC) κ-carrageenan (κ-CG):chitosan was obtained. Binding constant value (2.11 × 10(7)mol(-1)) showed high affinity of κ-CG to chitosan. The complex formation of κ-CG:chitosan 1:10 and 10:1 w/w was shown by centrifugation in a Percoll gradient. Using atomic force microscopy we showed that the supramolecular structure of the complexes is different from each other and from the macromolecular structure of the initial polysaccharides. The gastroprotective and anti-ulcerogenic effect of κ-CG, chitosan and their complexes was investigated on the model of stomach ulcers induced by indometacin in rats. PEC κ-CG:chitosan have gastroprotective properties which depend on their composition. Complex κ-CG:chitosan 1:10 w/w possesses higher gastroprotective activity than the complex 10:1 w/w. These results suggest that the gastroprotective effect of complexes can be associated with their protective layer on the surface of the mucous membrane of a stomach, which avoids a direct contact with the ulcerogenic agent.

Lappaconitine: influence of halogen substituent on the antiarrhythmic activity

The current paper presents research results related to antiarrhythmic activity of halogen-containing derivatives of lappaconitine. Lappaconitine derivatives with iodine, chlorine or bromine substituting the anthranilate moiety at C-5` position were shown in vivo and in vitro to exhibit a more (Br, I) or less (Cl) pronounced antiarrhythmic activity in the models of calcium chloride- and adrenaline-induced arrhythmias as compared with the reference compound lappaconitine. The intensity of antiarrhythmic action depending on halogen substituent was found to be expressed by the following order: Cl < I < Br.

Structure of the liver in mice with transplanted Lewis carcinoma during polychemotherapy and correction with betulonic acid and its derivatives

Morphological and morphometric studies of the liver with transplanted Lewis carcinoma were performed after polychemotherapy and correction with betulonic and [3-oxo-20(29)-lupene-28-oil]-3-aminopropionic acids and their methyl esters. It was demonstrated than betulonic and [3-oxo-20(29)-lupene-28-oil]-3-aminopropionic acids reduced the degree of degenerative changes and volume density of necrotic changes in hepatocytes after polychemotherapy. Methyl esters of these acids little changed the severity and spreading of destructive and necrotic changes in the liver caused by complex cytostatic therapy. It was also shown that all studied triterpenoids exhibited more pronounced antimetastatic effect (evaluated by the decrease in volume density of liver metastases) compared to polychemotherapy.

The complexes of drugs with carbohydrate-containing plant metabolites as pharmacologically promising agents

Complexation of known drugs with carbohydrate-containing plant metabolites is a promising way to synthesize new drugs that does not only save pharmacological properties of initial agent but also acquire a number of advantageous features such as increased water solubility, bioavailability and decreased toxicity. This review reports on the development and pharmacological evaluation of novel complexes of various well-known drugs with vegetable coplexation agents: glycyrrhizic acid, Stevia glycosides, gypsogenin tetraoside, pectin, xyloglucan, arabinogalactan. The aim of this review is to describe advantages of the new approach, suggested by authors, in the development of low toxic and high-performance drugs.

[Effects of chronic fluoxetine treatment on catalepsy and immune response in mice genetically predisposed to freezing reaction: the role of 5-HT1A and 5-HT2A receptors and tph2 and SERT genes]

ASC/Icg (Antidepressant Sensitive Catalepsy) mouse strain selected for high predisposition to pinch-induced catalepsy is characterized by depressive-like behavior and impaired immune response. Chronic treatment with SSRI fluoxetine attenuated catalepsy manifestation and normalized a decreased number of rosette-forming cells (RFC) in spleen in ASC mice. Chronic fluoxetine administration had no effect on catalepsy and RFC number in mice of parental cataleptic CBA/Lac strain. Fluoxetine failed to alter 5-HT1A receptor functional activity in mice of both strains and diminished 5-HT2A receptor functional activity in CBA but not in ASC mice. No effect on cortical 5-HT1A and 5-HT2A receptor mRNA levels and on 5-HT1A receptor, tph2 (tryptophan hydroxylase-2) and SERT (serotonin transporter) mesencephalic gene expression was observed in ASC mice. Other possible serotonergic mechanisms of fluoxetine effect on catalepsy and immune response in mice with depressive-like state are discussed.

Analgesic Properties of New Pyrrolidinomorphinane Derivatives: Revealing Potential Pathways

The pyrrolidinomorphinane derivatives have been found to be active in the writhing tests in mice with the analgesic effect being antagonized by naloxone. This suggests that analgesia is mediated by the opioid system. The compounds also displayed anti-inflammatory activity in formalin and histamine edema experimental models and the data may be evidence for anti-inflammatory activity involvement in the inhibition of pain reaction.

Cardiomyocyte count in rat myocardium under the effect of antitumor agents cyclophosphamide and triterpenoids

Structural reorganization of the myocardium in response to antitumor agents (cyclophosphamide, betulonic acid and its amide) was studied. Cardiotoxic effects of these chemicals manifested in cardiomyocyte contracture and lytic injuries and by significant hemodynamic disorders. The most pronounced lytic and necrobiotic changes in cardiomyocytes were detected after injection of cyclophosphamide followed by betulonic amide; this led to a more pronounced decrease in heart weight as a result of a decrease in total cardiomyocyte count. Antitumor drugs differently changed the ratio of mono- to binuclear cardiomyocytes, which differ by their regeneratory and compensatory adaptive potential.

[Effects of acute and chronic introduction of fluoxetine on anxiety-depressive condition of male and female mice]

The effects of acute and chronic fluoxetine treatment in intact and anxiety-depressive male and female inbred mice of the C57BL/6J strain were studied. The gender differences in the behaviour of mice in the tests estimating anxiety, locomotion and exploration activity, communication, and depressive-like state after fluoxetine injection were established. The dependence of fluoxetine treatment on normal or pathological state in mice was discovered. It was concluded that use of the animals in pathological condition and chronic (but nor acute) fluoxetine treatment are represented as the most correct estimative means of antidepressant efficiency.

Effect of n-tyrosol on blood viscosity and platelet aggregation

Experiments on rats showed that n-tyrosol limited the increase in blood viscosity during thermal exposure at a shear rate of 5-300 sec(-1) and inhibited ADP-induced platelet aggregation. The effects of n-tyrosol are comparable to that of pentoxyphylline.

Evaluation of magnetic resonance imaging characteristics of new nitroxyl radicals on the model of RLS lymphoma

Toxic and magnetic resonance contrast characteristics of new nitroxyl radicals Fur-135 and Fur-176 were studied in experiments on mice. The test compounds exhibited low toxicity and allowed us to increase contrasting of transplanted RLS lymphoma. Fur-135 differs by the type of contrasting from Gd(3+)-containing preparation omniscan and locates the tumor focus with high precision.

[Involvement of striatal serotonin in fluoxetine effects on adrenocortical function and behaviour]

Treatment of the adult rats with selective serotonin (5-HT) reuptake inhibitor: fluoxetine and its complexes with glycyrrizhinic acid during 2 weeks (25 mg/kg/day) significantly increased plasma corticosterone levels that were measured after 5-min plus-maze. All the drugs decreased the content of 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the striatum as well as 5-HT in the hippocampus. There was a significant negative correlation between 5-HT in the striatum and corticosterone levels. These data suggest that fluoxetine induces serotoninergic changes in the striatum that might be related to neuroendocrine and behavioural effects of the drug.

Hydrolytic approach for production of deoxyribonucleoside- and ribonucleoside-5 -monophosphates and enzymatic synthesis of their polyphosphates

A new, simple, and ingenious method for enzymatic synthesis of deoxy- and ribonucleoside-5 -triphosphates (dNTP and NTP, respectively) has been developed. The method includes the following stages: hydrolysis of DNA with DNase and immobilized S1-nuclease, phosphorylation of the resulting deoxy- and ribonucleoside-5 -monophosphates (dNMP and NMP, respectively) with nucleotidyl kinase from Escherichia coli, and purification by chromatography of the synthesized dNTP and NTP. dNMP was phosphorylated using an ATP-regenerating system based on acetokinase from E. coli and lithium acetylphosphate.

[The main pharmacokinetic parameters of p-tyrosol upon intravenous injection in rats. II. Verification of the pharmacokinetics linearity and evaluation of the possible accumulation]

The main pharmacokinetic parameters of p-tyrosol after single (in 3 doses) and repeated intravenous injection were studied in rats. The content ofp-tyrosol in the blood plasma was determined by spectrofluorimetric method. The pharmacokinetic parameters of p-tyrosol are linear in the dose range from 50 to 200 mg/kg. Repeated administration leads to accelerated metabolic elimination of p-tyrosol.

Antitumor and antimetastatic effects of betulonic acid amides in mice with transplantable Lewis carcinoma

We studied the effects of four synthetic amides of betulonic acid containing amino acid fragments (d,l-alpha-alanine, beta-alanine, and their methyl esters) on the rate of growth and metastatic dissemination of transplantable Lewis lung carcinoma in C57Bl/6 mice. The test compounds were administered intragastrically in a single dose of 500 mg/kg. 3-[-oxo-20(29)-lupen-28-oilamino]-propionic acid suppressed primary tumor growth (by 26%) and decreased the number of lung metastases (by more than 2 times). Antitumor and antimetastatic activity of triterpenoids decreased after methylation of the amino acid fragment in betulonic acid.

Biological activity and pharmacological prospects of lupane terpenoids: II. Semisynthetic lupane derivatives

The discussion of lupane triterpenoids as prospective medicinal preparations is continued, and semisynthetic triterpenoids are being discussed. Acyl derivatives that mainly exhibit high anti-HIV, antitumor, and organo-protective activities are described. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2006, vol. 32, no. 3; see also http://www.maik.ru.