Modulating Nitric Oxide: Implications for Cytotoxicity and Cytoprotection.

Despite the significant progress in the fields of biology, physiology, molecular medicine, and pharmacology; the designation of the properties of nitrogen monoxide in the regulation of life-supporting functions of the organism; and numerous works devoted to this molecule, there are still many open questions in this field. It is widely accepted that nitric oxide (•NO) is a unique molecule that, despite its extremely simple structure, has a wide range of functions in the body, including the cardiovascular system, the central nervous system (CNS), reproduction, the endocrine system, respiration, digestion, etc. Here, we systematize the properties of •NO, contributing in conditions of physiological norms, as well as in various pathological processes, to the mechanisms of cytoprotection and cytodestruction. Current experimental and clinical studies are contradictory in describing the role of •NO in the pathogenesis of many diseases of the cardiovascular system and CNS. We describe the mechanisms of cytoprotective action of •NO associated with the regulation of the expression of antiapoptotic and chaperone proteins and the regulation of mitochondrial function. The most prominent mechanisms of cytodestruction-the initiation of nitrosative and oxidative stresses, the production of reactive oxygen and nitrogen species, and participation in apoptosis and mitosis. The role of •NO in the formation of endothelial and mitochondrial dysfunction is also considered. Moreover, we focus on the various ways of pharmacological modulation in the nitroxidergic system that allow for a decrease in the cytodestructive mechanisms of •NO and increase cytoprotective ones.

Combined Pharmacological Modulation of Translational and Transcriptional Activity Signaling Pathways as a Promising Therapeutic Approach in Children with Myocardial Changes.

Myocardial hypertrophy is the most common condition that accompanies heart development in children. Transcriptional gene expression regulating pathways play a critical role both in cardiac embryogenesis and in the pathogenesis of congenital hypertrophic cardiomyopathy, neonatal posthypoxic myocardial hypertrophy, and congenital heart diseases. This paper describes the state of cardiac gene expression and potential pharmacological modulators at different transcriptional levels. An experimental model of perinatal cardiac hypoxia showed the downregulated expression of genes responsible for cardiac muscle integrity and overexpressed genes associated with energy metabolism and apoptosis, which may provide a basis for a therapeutic approach. Current evidence suggests that RNA drugs, theaflavin, neuraminidase, proton pumps, and histone deacetylase inhibitors are promising pharmacological agents in progressive cardiac hypertrophy. The different points of application of the above drugs make combined use possible, potentiating the effects of inhibition in specific signaling pathways. The special role of N-acetyl cysteine in both the inhibition of several signaling pathways and the reduction of oxidative stress was emphasized.

5+1-Heterocyclization as preparative approach for carboxy-containing triazolo[1,5-c]quinazolines with anti-inflammatory activity.

Present article is devoted to the purposeful search of novel anti-inflammatory agents among carboxyl-containing partially hydrogenated [1,2,4]triazolo[1,5-с]quinazolines and products of their tandem cyclization. It has been shown that target compound's could be obtained via interaction between [2-(3-R-1H-1,2,4-triazol-5-yl)phenyl]amines and oxo-containing carboxylic acids and their esters of various structure. The structures of synthesized compounds were verified by appropriate methods, the features of NMR-spectra patterns were discussed as well. The low predicted toxicity of obtained compounds has been estimated using in silico methods. In vivo study on the model of acute aseptic inflammation (carrageenan test) have been revealed that synthesized compounds expose anti-inflammatory activity in the range of 0.94-52.66%. 4-(2-(Ethoxycarbonyl)-5,6-dihydro-[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acid has been identified as most active compound. Additionally, the effects of some (2-R-5,6-dihydro[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acids (compounds 3) on the levels of key inflammatory markers have been estimated. It has been shown that studied compounds decrease the level of neutrophils, COX-2, nitrotyrosine, IL-1b, C-reactive protein and increase level of eNOS. 4-(2-(Ethoxycarbonyl)-5,6-dihydro-[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acid (3.2) has been identified as compound with most expressed anti-inflammatory activity and significant effect on the levels of marker of inflammatory processes. Molecular docking study towards СОХ-1 and СОХ-2 has been conducted to substantiate possible mechanism of obtained compounds anti-inflammatory activity. It has been found that fixation of 4-(2-(ethoxycarbonyl)-5,6-dihydro-[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acid (3.2) molecule in active site of enzyme is outstandingly similar to the reference ligands. The essential value of carboxylic group for presence of anti-inflammatory activity has been estimated as result of SAR-analysis. It has been found that studied class of compounds is perspective for further structural modification aimed to the creation of novel anti-inflammatory agents.

Molecular and biochemical mechanisms of diabetic encephalopathy.

Diabetes mellitus is one of the important independent risk factors for the development of neurological disorders such as ischemic stroke, transient ischemic attacks, vascular dementia and neurodegenerative processes. Hyperglycemia plays a crucial role as a trigger in the pathogenesis of these disorders. In this review, we summarize the existing data on the molecular mechanisms of diabetic encephalopathy development, consider the features of oxidative and nitrosative stresses, changes in the thiol-disulfide system, as well as mitochondrial and endothelial dysfunction in diabetes. We focus on the role of HSP 70 in cellular responses in diabetic encephalopathy. HSP70 protein is an important component of the endogenous system of neuroprotection. It acts as an intracellular chaperone, providing the folding, retention, and transport of synthesized proteins, as well as their degradation under both normoxic and stress-induced denaturation conditions. HSP70 can be considered a molecular marker and a promising therapeutic target in the treatment of diabetes mellitus.

Altered Blood Molecular Markers of Cardiovascular Function in Rats after Intrauterine Hypoxia and Drug Therapy.

Many children and adults who have suffered prenatal hypoxia at an early age develop many serious diseases. This disease is an actual problem of pediatric cardiology and little studied. The aim was to analyze the cardioprotective effect of L-arginine, Thiotriazoline, Angioline, and Mildronate on the cardiovascular system of rats after prenatal hypoxia. Methods: The experiments were carried out on 50 female white rats; intraperitoneal sodium nitrite solution was administered daily to pregnant female rats after 16 days at a dose of 50 mg/kg. Control pregnant rats received saline. The offspring were divided into groups: 1-intact; 2-the control group of rat pups after PH, treated daily with physiological saline; 3-six groups of rat pups after PH, treated daily from the 1st to the 30th day after birth. Heat shock protein HSP70 was determined by enzyme immunoassay, ST2 Nitrotyrosine, and eNOS was observed by ELISA. Results: Angiolin showed a high cardioprotective effect even a month after discontinuation of the drug, and after introduction, the highest decrease in ST2 nitrotyrosine was revealed. Thiotriazoline and L-arginine have an antioxidant effect and a positive effect on eNOS expression, increasing the concentration of HSP70. Mildronate increased the expression of eNOS and the concentration of HSP70 in the blood of experimental rats after a course of administration, but did not show an antioxidant effect and did not reduce the concentration of nitrotyrosine. The results obtained indicate the cardioprotective effect of modulators of the NO system with different mechanisms of action of drugs after prenatal hypoxia.

Cardioprotective Activity of Pharmacological Agents Affecting NO Production and Bioavailability in the Early Postnatal Period after Intrauterine Hypoxia in Rats.

Intrauterine hypoxia in newborns leads to a multifaceted array of alterations that exert a detrimental impact on the cardiovascular system. The aim of this research was to assess the cardioprotective effects of modulators of the nitric oxide (NO) system, including L-arginine, Thiotriazoline, Angiolin, and Mildronate, during the early postnatal period following intrauterine hypoxia. Methods: The study involved 50 female white rats. Pregnant female rats were given a daily intraperitoneal dose of 50 mg/kg of sodium nitrite starting on the 16th day of pregnancy. A control group of pregnant rats received saline instead. The resulting offspring were divided into the following groups: Group 1-intact rats; Group 2-rat pups subjected to prenatal hypoxia (PH) and daily treated with physiological saline; and Groups 3 to 6-rat pups exposed to prenatal hypoxia and treated daily from the 1st to the 30th day after birth. Nitrotyrosine levels, eNOS, iNOS, and NO metabolites were evaluated using ELISA; to measure the expression levels of iNOS mRNA and eNOS mRNA, a PCR test was utilized. Results: Angiolin enhances the expression of eNOS mRNA and boosts eNOS activity in the myocardium of rats with ischemic conditions. Arginine and particularly Thiotriazoline exhibited a consistent impact in restoring normal parameters of the cardiac nitroxidergic system following PH. Mildronate notably raised iNOS mRNA levels and notably reduced nitrotyrosine levels, providing further support for its antioxidative characteristics.

Protective effect of vaginal resveratrol administration on joint tissues in ovariectomized rats: Targeting mTOR and сaspase 3.

INTRODUCTION: Estrogens play a considerable role in maintaining bone and articular cartilage homeostasis. Menopause provokes joint disorders due to metabolic syndrome and altered signaling pathways. Phytoestrogen resveratrol was demonstrated to provide chondroprotective and osteoprotective effects. However, the mechanisms of such action of Resveratrol are still being explored. AIM: The study aims to determine the effect of Resveratrol on the joints and its therapeutic mechanism in ovariectomized rats. MATERIAL AND METHODS: The study was carried out on Wistar female rats that were divided into three groups, including control animals; ovariectomized rats (OVX); and the OVX group treated with an intravaginal gel containing Resveratrol (0.5 % 0.1 mL, daily 28 days). Knee joint tissues (articular cartilage, subchondral plate, subchondral bone) were assessed by histomorphometry. The expression of mTOR, PTEN, Caspase 3 and BCL-2 in articular cartilage and subchondral bone were evaluated immunohistochemically. RESULTS: Resveratrol treatment of OVX rats prevented weight gain by 17 % (P < 0.001), demonstrating the systemic effect on metabolic pathways. Although there were no statistically significant differences in the thickness of articular cartilage between groups, OVX rats possessed degenerative changes in chondrocytes, associated with the enhanced expression of mTOR (P < 0.001) and Casp-3 (P = 0.005). Resveratrol decreased mTOR (P = 0.007) and Casp-3 (P = 0.011) expression in chondrocytes, reducing degenerative changes. At the same time, resveratrol attenuated the deterioration of trabecular bone in OVX rats (P = 0.002). This effect was through the up-regulation of BCL-2 (P = 0.018) and down-regulation of Casp-3 expression (P < 0.001). CONCLUSIONS: Intravaginal administration of resveratrol provided systemic effects and ameliorated joint tissue structure and signaling in OVX rats through stimulation of BCL-2 and reduced Casp-3 expression.

Involvement of heat shock proteins HSP70 in the mechanisms of endogenous neuroprotection: the prospect of using HSP70 modulators.

This analytical review summarizes literature data and our own research on HSP70-dependent mechanisms of neuroprotection and discusses potential pharmacological agents that can influence HSP70 expression to improve neurological outcomes and effective therapy. The authors formed a systemic concepts of the role of HSP70-dependent mechanisms of endogenous neuroprotection aimed at stopping the formation of mitochondrial dysfunction, activation of apoptosis, desensitization of estrogen receptors, reduction of oxidative and nitrosative stress, prevention of morpho-functional changes in brain cells during cerebral ischemia, and experimentally substantiated new target links for neuroprotection. Heat shock proteins (HSPs) are an evolutionarily integral part of the functioning of all cells acting as intracellular chaperones that support cell proteostasis under normal and various stress conditions (hyperthermia, hypoxia, oxidative stress, radiation, etc.). The greatest curiosity in conditions of ischemic brain damage is the HSP70 protein, as an important component of the endogenous neuroprotection system, which, first of all, performs the function of intracellular chaperones and ensures the processes of folding, holding and transport of synthesized proteins, as well as their degradation, both under normoxic conditions and stress-induced denaturation. A direct neuroprotective effect of HSP70 has been established, which is realized through the regulation the processes of apoptosis and cell necrosis due to a long-term effect on the synthesis of antioxidant enzymes, chaperone activity, and stabilization of active enzymes. An increase in the level of HSP70 leads to the normalization of the glutathione link of the thiol-disulfide system and an increase in the resistance of cells to ischemia. HSP 70 is able to activate and regulate compensatory ATP synthesis pathways during ischemia. It was found that in response to the cerebral ischemia formation, HIF-1a is expressed, which initiates the launch of compensatory mechanisms for energy production. Subsequently, the regulation of these processes switches to HSP70, which "prolongs" the action of HIF-1a, and also independently maintains the expression of mitochondrial NAD-dependent malate dehydrogenase activity, thereby maintaining the activity of the malate-aspartate shuttle mechanism for a long time. During ischemia of organs and tissues, HSP70 performs a protective function, which is realized through increased synthesis of antioxidant enzymes, stabilization of oxidatively damaged macromolecules, and direct anti-apoptotic and mitoprotective action. Such a role of these proteins in cellular reactions during ischemia raises the question of the development of new neuroprotective agents which are able to provide modulation/protection of the genes encoding the synthesis of HSP 70 and HIF-1a proteins. Numerous studies of recent years have noted the important role of HSP70 in the implementation of the mechanisms of metabolic adaptation, neuroplasticity and neuroprotection of brain cells, so the positive modulation of the HSP70 system is a perspective concept of neuroprotection, which can improve the efficiency of the treatment of ischemic-hypoxic brain damage and be the basis for substantiating of the feasibility of using of HSP70 modulators as promising neuroprotectors.

2-[(3-Aminoalkyl-(alkaryl-,aryl-))-1H-1,2,4-triazol-5-yl]anilines: synthesis and anticonvulsant activity.

The presented work is devoted to the development of synthesis methods for novel 2-[(3-aminoalkyl-(alkaryl-, aryl-))-1H-1,2,4-triazolo]anilines. Abovementioned compounds were obtained via hydrazinolysis (Ing-Manske procedure) and acid hydrolysis of corresponding N -acylated{([1,2,4]triazolo[1,5-c]quinazolin-2-yl)alkyl-(alkaryl-, aryl-)}amines. The regioselectivity of hydrazinolysis and hydrolysis were established. The features of spectral characteristics werestudied and discussed. Characteristic patterns of protons signals splitting in 1H NMR of the synthesized compounds were established. The effect of the synthesized compounds on the pentylenetetrazol seizures was studied. It was found that according to some indicators, anticonvulsant activity of 2-[(3-aminoalkyl-(alkaryl-, aryl-))-1H-1,2,4-triazolo]anilines superior or comparable with effect of the reference drug "Lamotrigine". It is a valid argument for their further structural modification, in-depth study of activity mechanisms and further study of anticonvulsant activity on other experimental seizures models.

Antihypertensive and cardioprotective effects of new compound 1-(ß-phenylethyl)-4-amino-1,2,4-triazolium bromide (Hypertril).

Despite the success which was achieved in the treatment of arterial hypertension, the problem remains actual. At the departments of pharmaceutical chemistry and pharmacology of the Zaporozhye State Medical Institute (Ukraine), our research team isolated the compound 1-(ß-phenylethyl)-4-amino-1,2,4-triazolium bromide (Hypertril) as derivative of 4-amino-1,2,4-triazole. The objectives of this investigation were the study of cardioprotective and antihypertensive activities of this new compound Hypertril and we used the Spontaneously hypertensive rats (SHR) as an experimental model. We discovered that Hypertril has a reliable dose-dependent antihypertensive effect in the dose range 5-20 mg/kg after 30-day administration and this antihypertensive effect of Hypetril competes or significantly exceeds Metoprolol (20 mg/kg). Our studies obtained evidence of a dose-dependent improvement of myocardial energy metabolism. Hypertril reduces the manifestations of secondary mitochondrial dysfunction due to arterial hypertension. Hypertril can prevent oxidative modification of the protein; also Hypertril reduces the insufficiency of mitochondrial pores. As a result, Hypertril increases the content of ATP in the myocardium of SHR, normalizes the activity of mitochondrial enzymes, decreases lactate production and increases pyruvate. Hypertril enhances the cardioprotective effects of NO and increases the resistance of the cardiomyocytes to ischemia. The use of Hypertril leads to a dose-dependent increase of the density of cardiomyocyte nuclei, significant increase RNA content in nuclei and the cytoplasm of cardiomyocytes, and an increase of the nuclear-cytoplasmic index. These changes indicate a decrease of myocardial hypertrophy.

Search for substances with antioxidant and antiamnestic activities among 2-substituted 4-(3H)-quinazolones.

We have synthesised some of 2-substituted 4-(3H)-quinazolones by the reaction with benzaldehyde and cinnamic aldehyde and their derivatives. It is shown that the intensity of the reaction depends on electrophilic properties of carbonyl compounds and steric factors. The elemental analysis, ultraviolet (UV), infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of synthesised compounds, their individuality being checked by thin-layer chromatography. The results of biological experiments show that the synthesised 2-substituted 4-(3H)-quinazolones have an expressed antioxidant and antiamnestic activity and are prospective for further research of their nootropic activity.