Antipyretic activity of the new 2-(((3-mercapto-5-methyl-4н-1,2,4-triazol-4-yl)imino)methyl)-5-r-benzoates

Temperature rise is an important defensive mechanism of the body that activates immune system and increases phagocytosis, suppressing viral and microbial growth. Antipyretic activity, which involves the increase of thermolysis through angiectasis of skin vessels and heightened sweat production, is largely connected with a relaxing effect on the diencephalon’s thermoregulation centers’ irritation that may be altered due to disease. Body temperature higher than 39°C poses a threat to human health, including people of any age, from kids to adults of all ages. Despite analgesics’ high effectiveness, their use is not entirely safe. The use of aspirin impairs blood coagulation and increases the risk of inflammatory processes in gastroenteric tract and causes angiasthenia. The search and study of the new highly effective antipyretic medicines is greatly relevant nowadays. The aim of this work is to conduct a pharmacological screening over the new antipyretic drugs, specifically the derivatives of 2-(((3-mercapto-5-methyl-4Н-1,2,4-triazol-4-yl)imino)methyl)-5-R-benzoate that were obtained for the first time. Materials and methods. The objects of the research were the new 2-(((3-mercapto-5-methyl-4Н-1,2,4-triazol-4-yl)imino)methyl)-5-R-benzoate derivatives. The experimental fever was caused in white nonlinear rats by administrating 2,4-dinitrophenol (2,4-DNP), a dividing agent in oxidative phosphorylation, at the dose of 20 mg/kg. Acetylsalicylic acid was administrated to the reference group of animals at the dose of 100 mg/kg. The substances of research were administrated in 30 minutes (Т 0,5 ) after rats received 2,4-DNP, body temperatures were recorded during 1 hour (Т 1 ). The initial rectal temperature (Т 0 ) was recorded prior the abdominal injection of 2,4-DNP. Acetylsalicylic acid was used as a reference substance at the dose of 100 mg/kg. Results and discussion. The results of the experiment established that in 30 minutes after the abdominal injection of 2,4-DNP, body temperature in the population of rats (n=133) was in range from 37.36 °C to 38.37 °C on average ( Δ Т=0.88°C). As for the reference substance acetylsalicylic acid, it caused a 3 % decrease of body temperature in rats with a modeled pathology ( Δ Т=-1.2 °С, р≤0.05) with relation to the reference group. The results demonstrated that antipyretic activity of some of the substances was better than that of the reference substance. Hence, substances IV, V, and VIII decreased body temperature in rats by more than 0.39 %. Among the studied entities, substances IV and V are the most promising; they decreased body temperature in rats by 4.66-4.95 %, or by 1.19-2.10°C, with relation to the reference group. Conclusions New 2-(((3-mercapto-5-methyl-4Н-1,2,4-triazol-4-yl)imino)methyl)-5-R-benzoate derivatives were obtained. Ammonium 2-(((3-mercapto-5-methyl-4Н-1,2,4-triazol-4-yl)imino)methyl)-5-R-benzoate is the most active substance. Introduction of inorganic cations leads to the loss of activity. Introduction of piperedinium leads to a slight increase of activity, but still it is weaker than that of the reference substance


Introduction
Thermoregulation of the body relies on the balance of physiological processes of thermogenesis and thermolysis, which are controlled by neural and hormonal mechanisms. Antipyretic activity, which involves the increase of thermolysis through angiectasis of skin vessels and heightened sweat production, is largely connected with a relaxing effect on the diencephalon's thermoregulation centers' irritation that may be altered due to disease [1].
Antipyretic drugs represent the type of medicines capable of decreasing body temperature during fever and belong to the group of non-steroidal anti-inflammatory drugs (NSAIDs) [2,3]. Despite analgesics' high effectiveness, their use is not entirely safe. The use of aspirin impairs blood coagulation and increases the risk of inflammatory processes in gastroenteric tract [4].
As for the drug paracetamol, it is worth noting that its side effects are very rare. However, once manifested, they are of a rather high severity. Paracetamol administration increases the risk of myocardial infarction, premature death, gastrorrhagia, and acute liver or kidney diseases [5].
Literary sources indicate that both ibuprofen and analgin (dipyrone) are well-tolerated and safe during short-term administration to kids affected by fever.
However, the review of antipyretic activity showed that ibuprofen causes higher antipyretic effect than analgin during oral administration of one dose. This effect is more noticeable in kids with high temperature [6].

Formulation of the problem in a general way, the relevance of the theme and its connection with important scientific and practical issues
The search and study of the new highly effective antipyretic medicines is of a great significance nowadays.The sources [7,8] report that the derivatives of 1,2,4-triazol-3-thione possess a wide range of biological activity.

Analysis of recent studies and publications in which a solution of the problem and which draws on the author
Several articles describe the results of the study of antipyretic activity of 1,2,4-triazole derivatives. That said, the study [9] provides information on the antipyretic activity of new 2-(5-(adamantan-1-yl)-4-R-1,2,4-triazol-3ylthio)acetate hydrazides. Another scholarly source [10] also describes new S-derivatives of 1,2,4-triazole that contain morpholinomethylene substituent in their structures, which makes them promising as antipyretic drugs.

Allocation of unsolved parts of the general problem, which is dedicated to the article
The heterocyclic nature of 1,2,4-triazole makes it a promising fragment for synthesis of new biologically active compounds, and antipyretics in particular. The search for the new highly effective antipyretic medicines is of a great relevance nowadays.

Statement of the basic material of the study (methods and objects) with the justification of the results
Materials and methods.
The objects of the research were the new 2-(((3mercapto-5-methyl-4Н-1,2,4-triazol-4-yl)imino)methyl)-5-R-benzoate derivatives obtained in the Laboratory of organic synthesis at the Department of toxicological and inorganic chemistry of Zaporizhzhia State Medical University under the supervision of professor Panasenko O. I. and professor Knysh Ye. H.
In our opinion, the model of hyperthermia caused by 2,4-dinitrophenyl is the most convenient for screening.
The substances of research were administrated abdominally at the dose of 1/10 LD 50 , substances were stabilized with Twin-80. The doses were determined by Prozorovskyi method prior the preparation [12].
According to the mentioned model, body temperature rises during 15-20 minutes after the injection of 2,4-DNP, while the temperature maximum is reached during 1 hour. Therefore, it was reasonable to inject the substances of research in 30 minutes (Т 0,5 ) after the administration of 2,4-DNP and to record rectal temperature during 1 hour (Т 1 ).
The initial rectal temperature (Т 0 ) was recorded prior the abdominal injection of 2,4-DNP. Acetylsalicylic acid was used as a reference substance at the dose of 100 mg/kg.
The results were processed with modern methods of statistical analysis, including Microsoft Office 2010 (Microsoft Excel) and STATISTICA® for Windows 6.0. Mean values (M) and standard errors of the average (±m) were calculated. Data validity of intergroup variances as per experimental data were evaluated using Student's ttest. Three levels of statistical significance were applied in the processing, specifically р<0.05; р<0.01; and р<0.001 [13,14].

Results and discussion
The obtained data (Table 1) demonstrates that the study substance and the reference substance affected rats' body temperatures in a different manner.
As for the reference substance acetylsalicylic acid, it caused a 3 % decrease of body temperature in rats with a modeled pathology ( Δ Т=-1.2 o С, р≤0.05) with relation to the reference group.
The results clearly illustrate that antipyretic activity of some of the substances was better than that of the reference substance. That said, substances IV, V, and VIII decreased body temperature in rats by more than 0.39 %.
Therefore, substances IV and V deserve the most of attention; they decreased body temperature in rats by 4.66-4.95 %, or by 1.19-2.10 °C, with relation to the reference group.
2. Introduction of inorganic cations leads to the loss of activity.
3. If piperidinium forms the salt (II), the activity increases slightly, but the compound demonstrates weaker effect than the reference substance.
4. The possible mechanism of antipyretic activity of the new compounds is the inhibition of cyclooxygenase [15,16].
5. The problem of finding new highly effective antipyretics is of a great importance nowadays. That is why 1,2,4-triazole derivatives merit further pharmacological research.
Having conducted a literature review and the study, we found that the newly synthesized compounds merit further research of their antipyretic activity with aim to find the new highly effective drugs with biological activity that have a potential to appear as active pharmaceutical ingredients of commercial antipyretic medicines.