Immunomodulatory Action of Substituted 1,3,4-Thiadiazines on the Course of Myocardial Infarction

This review focuses on the biological action of the compounds from the group of substituted 1,3,4-thiadiazines on stress response and myocardial infarction. The aim of this review is to propose the possible mechanisms of action of 1,3,4-thiadiazines and offer prospectives in the development of new derivatives as therapeutic agents. It is known, that compounds that have biological effects similar to those used as antidepressants can down-regulate the secretion of proinflammatory cytokines, up-regulate the release of anti-inflammatory ones and affect cell recruitment, which allows them to be considered immunomodulators as well. The results of pharmacological evaluation, in silico studies, and in vivo experiments of several compounds from the group of substituted 1,3,4-thiadiazines with antidepressant properties are presented. It is proposed that the cardioprotective effects of substituted 1,3,4-thiadiazines might be explained by the peculiarities of their multi-target action: the ability of the compounds to interact with various types of receptors and transporters of dopaminergic, serotonergic and acetylcholinergic systems and to block the kinase signal pathway PI3K-AKT. The described effects of substituted 1,3,4-thiadiazines suggest that it is necessary to search for a new agents for limiting the peripheral inflammatory/ischemic damage through the entral mechanisms of stress reaction and modifying pro-inflammatory cytokine signaling pathways in the brain.

2-Morpholino-5-Phenyl-6H-1,3,4-Thiadiazine Corrects Metabolic Disorders during the Development of Alloxan Diabetes Mellitus in Rats

Metabolic disorders were evaluated in rats with alloxan diabetes mellitus after administration of 2-morpholino-5-phenyl-6H-1,3,4-thiadiazine (compound L-17). Administration of L-17 reduced the severity of metabolic disorders associated with diabetes mellitus. At the end of the experiment, the concentration of glucose, glycated hemoglobin, malonic dialdehyde, and catalase activity were significantly higher and peroxidase activity was significantly lower in the group of animals receiving L-17. The decrease of glycemia, glucose concentration, and glycated hemoglobin content was reached by the 3rd-4th week of the experiment. These data suggest that correction of biochemical parameters in rats with alloxan diabetes was reached after administration of L-17 for at least 3 weeks.

Effect of a new class of compounds of the group of substituted 5R1, 6H2-1,3,4-thiadiazine-2-amines on the inflammatory and cytokine response in experimental myocardial infarction

This study investigated the effects of the L-17 compound of the group of substituted 5R1, 6H2- 1,3,4-thiadiazine-2-amines on the immune response and the plasma level of circulating cytokines in acute myocardial infarction (MI) in rats. The study was based upon experimental work which demonstrated the role of local and systemic inflammatory reactions in MI. Acute MI in rats was induced by left coronary artery coagulation. Histological study of the myocardium sections has been carried out at the 1(th) and 7(th) days of the experimental myocardial infarction. Serum activity of creatine phosphokinase (CPK), aspartate aminotransferase (AST), isoenzymes 1 and 2 and lactate dehydroge nase (LDH1-2) were investigated at days 1(st)and 7(th). ELISA analysis for plasma cytokine levels was performed using commercially available test kits following the manufacturer's instructions. Biochemical analysis in animals with the administration of the L-17 compound after MI showed that the AST and CPK levels at days 5 and 7 of experiments did not differ significantly from the values of intact animals. In animals of the group with MI without the administration of the L-17 compound, the IL-1 level 8 times and the TNF level 7.8 times exceeded the normal indicators, while the use of L-17 compound in the therapy resulted in only 1.8 times increase of IL-1 level and 4.7 times increase of TNF level in comparison with the norm. Thus, the introduction of L-17 compound in case of experimental MI delays exudative/alternative phase of inflammation, accelerates granulocytic and decreased the inflammation and anti-inflammation interleukins level.

Modulation of inflammatory response improves myocardial infarct healing in rats

It is reputed that the ideal therapeutic approaches to treatment of patients with acute coronary syndrome (ACS) and myocardium infarction (MI) should be aimed at the inflammation reaction triggers. This study investigated the effectiveness of the impact of L- 17 compound of the group of 5- phenyl substituted-6H-1,3,4-thiadiazine-2-amines upon the course of experimental MI as compared to the impact of a preparation, officially registered in Russia as an immunomodulator, Tamerit, belonging to phthalhydrazid derivative substance. Acute MI in rats was induced by left coronary artery coagulation. Histological study of the myocardium sections and biochemical analysis has been carried out at the 1st and 7th days of the experimental MI. The conducted investigations have shown that under the action of immunocorrectors the inflammation reaction character changes, exudative/destructive inflammation is replaced by a proliferative-cellular one. Animals' blood biochemical analysis at the background of L-17 and Tamerit introduction has shown a decrease of aminotransferases and lactatedehydrogenases activity in blood as compared to the reference group of animals' indicators, which is evidently caused by epicardial injury of myocardium and lesser amount of the alternative cardiomyocytes. At the same time, no noticeable difference in biochemical characteristics in groups, having been treated to immunomodulators of different chemical composition was identified, which is the sign of the essential similarity of their impact. Thus, immunocorrectors of different chemical groups (Tamerit and compound L17) diminish the volume of initial myocardial infarction and accelerate the granulation processes in course of MI, and represent a new category of treatment agents.

[The antiaggregant action of 2-morpholino-5-(thienyl-2)-6-H-1,3,4-thiadiazine in in vitro and ex vivo experiments]

The influence of 2-morpholino-5-(thienyl-2)-6-H-1,3,4-thiadiazine (H-29) on the platelet aggregation has been studied in experiments on donor plasma in vitro. It is established that H-29 causes a decrease in the platelet interaction induced by ADP and arachidonic acid. The influence of H-29 on platelet aggregation was also studied in ex vivo experiments with intravenous and oral administration, and some parameters of plasmatic hemostasis were evaluated.

[Influence of new 1,3,4-thiadiazines on platelet aggregation in vitro and ex vivo]

The influence of new original 1,3,4-thiadiazines on the human platelet aggregation in vitro was studied. All substances inhibited the platelet aggregation induced by both ADP and arachidonic acid. 1,3,4-Thiadiazines L-19, H-30 and L-37 were the most effective inhibitors. Effect of the intravenous injection of L-19 in various doses on platelet aggregation and some parameters of plasmatic hemostasis were studied ex vivo.

[Antiaggregant properties of new 1,3,4-thiadiazine derivatives]

A series of new 1,3,4-thiadiazine derivatives have been synthesized and their effect on the human platelet aggregation in vitro has been studied. All the tested substances inhibit the human platelet aggregation induced by ADP and arachidonic acid in a broad concentration range. The most active 1,3,4-thiadiazines (L-19, L-28 and L-31) effectively inhibit platelet aggregation at concentrations within 0.01-1 mM.