Low-dose Digoxin Enhances the Anticonvulsive Potential of Carbamazepine and Lamotrigine in Chemo-induced Seizures with Different Neurochemical Mechanisms

"Non-antiepileptic" drugs have a strong potential as adjuvants in multidrug-resistant epilepsy treatment. In previous study the influence of low doses of digoxin, which do not affect the myocardium, on the anticonvulsant potential of classical commonly used anti-epileptic drugs under conditions of seizures, induced by pentylenetetrazole and maximal electroshock, has been investigated. The aim of the study was to investigate the influence of digoxin at a sub-cardiotonic dose on the anticonvulsant potential of carbamazepine and lamotrigine in experimental seizures with different neurochemical mechanisms. Material and methods: A total of 192 random-bred male albino mice weighting 22–25 g were used. Carbamazepine and lamotrigine were administered intragastrically in conditionally effective (ED50) and sub-effective (½ ED50) doses: carbamazepine at doses of 100 and 50 mg/kg; lamotrigine at doses of 25 and 12.5 mg/kg. Digoxin was administered subcutaneously at a sub-cardiotonic dose of 0.8 mg/kg as an adjuvant to carbamazepine and lamotrigine in ½ ED50. Picrotoxin (2.5 mg/kg subcutaneously); thiosemicarbazide (25 mg/kg intraperitoneally); strychnine (1.2 mg/kg subcutaneously); camphor (1000 mg/kg intraperitoneally) were used as convulsant agents. Results: It was found that digoxin not only has its own permanent anticonvulsant effect on different models of paroxysms with different neurochemical mechanisms of development, but also significantly enhances the anticonvulsant potential of carbamazepine (to a lesser extent – lamotrigine) regardless of the pathogenesis of experimental paroxysms. Conclusion: Based on the results, it can be concluded that digoxin has a high potential as an adjuvant medicine in complex epilepsy treatment because it enhances the efficiency of low-dose traditional anticonvulsants carbamazepine and lamotrigin

An Overview on 1,2,4-triazole and 1,3,4-thiadiazole Derivatives as Potential Anesthesic and Anti-inflammatory Agents

The aim. The purpose of this review is to summarize data on the synthesis and structural modification of heterocyclic systems with triazole and thiadiazole fragments in molecules as promising objects in bioorganic and medicinal chemistry. Materials and methods. The research based on bibliosemantic and analytical methods using bibliographic and abstract databases, as well as databases of chemical compounds. Results. Modern medicinal chemistry faces many challenges, one of which is the determination of the activity and specificity of therapeutic agents. Recent scientific data showed that triazoles and/or thiadiazoles have broad spectrum of biological activities, in particular antimicrobial, antifungal, antiviral, anticancer and anticonvulsant. Synthetic research allows to propose a whole number of new molecular design directions of biological active triazole and/or thiadiazole derivatives, as well as to obtain directed library that include hundreds of new compounds. This review is an effort to summarize data of its analgesic and anti-inflammatory activity over the last decade. We summarized and analyzed the series of triazole and/or thiadiazole derivatives and provided data of their structure-activity relationship. For optimization and rational design of highly active molecules with optimal «drug-like» characteristics and discovering of possible mechanism of action SAR, QSAR analysis and molecular docking were summarized. Conclusions. It has been shown that heterocyclic systems containing fragments of triazole and / or thiadiazole are a significant source of promising analgesic and/or anti-inflammatory agents. It has been established that the mentioned heterocyclic derivatives have a high selectivity of action, low toxicity and an effect commensurate with standard drug

Synthesis and Anticonvulsant Activity Evaluation of N-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1h-quinazolin-3-yl)acetamide Novel 1-benzylsubstituted Derivatives

The aim. Synthesis of 1-benzylsubstituted derivatives of N-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1h-quinazolin-3-yl)acetamide, and determination of affinity to GABAergic biotargets with the following anticonvulsant activity estimation using PTZ-induced seizures model in mice. Materials and methods. Standard organic synthesis methods were used; the structure of the synthesized compounds was proved by elemental analysis, 1H and 13C NMR spectroscopy, and LC/MS method; composition of the synthesized compounds – by elemental analysis, their individuality – by TLC and LC/MS methods. AutoDockTools-1.5.6, as well as AutoDock Vina software, was used to perform molecular docking. Anticonvulsant activity was studied using pentylenetetrazole-induced seizures in mice. Results. A targeted N-[(2,4-dichlorophenyl)methyl]-2-(1-(R-benzyl)-2,4-dioxo-quinazolin-3-yl)acetamides were obtained by alkylation of N-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1H-quinazolin-3-yl)acetamide by corresponding 1-chloromethylbenzene in dimethylformamide environment with excess of potassium carbonate at a temperature 70-80 ˚С. Prediction of activity of 1-benzyl derivatives in the pentylenetetrazole-induced seizures in an in vivo experiment was carried out according to the obtained results of docking studies – affinity calculation for GABA receptor and GABA enzyme active sites, as well as analysis of conformational placement in them. In relation to the binding energy, the studied ligands were inferior to the reference drugs: GABA receptor positive allosteric modulators – benzamidine and diazepam, and GABA inhibitor – vigabatrin. The synthesized substances did not show anticonvulsant activity: only 2 compounds have shown a tendency to their activity manifestation according to the criterion of integral protective indicator – reduction of mortality by 17 % compared to control, as well as prolonging the time death of the animals. Comparison with the preliminary obtained results of the activity of the promising anticonvulsant N-[(2,4-dichlorophenyl)methyl] -2-(2,4-dioxo-1H-quinazolin-3-yl) acetamide N-[(2,4-dichlorophenyl)methyl]-2-(2,4-dioxo-1H-quinazolin-3-yl)acetamide made possible to prove the pharmacophore role of the cyclic amide fragment in anticonvulsant activity manifestation. Conclusion. The synthesis of N-[(2,4-dichlorophenyl)methyl]-2-(1-(R-benzyl)-2,4-dioxo-quinazolin-3-yl)acetamides, which have not still described in the literature, was carried out, as well as the structure of the mentioned compounds was proved. Unfortunately, the substances did not show anticonvulsant activity on the model of pentylenetetrazole-induced seizures. However, the obtained results allowed establishing the key role of the NHCO cyclic fragment on anticonvulsant activity. A positive correlation between the results of in vivo studies and in silico calculations was found – the model of pentylenetetrazole-induced seizures and docking into the active sites of PAMs GABAА receptor and enzyme inhibitor GABAАТ, which allows to recommend the given docking methodology as a tool to streamline and optimize the screening on the mentioned mode

The Influence of Non-steroidal Anti-inflammatory Drugs with Different Mechanisms of Action on the Course of Stress Reaction, the Functional State of Kidneys, Liver, and Heart on the Model of Acute General Cooling

Inhibitors of the arachidonic acid cascade have significant potential as the agents for the prevention of severe cold injuries. The results of the previous studies have demonstrated the pronounced frigoprotective properties of certain non-steroidal anti-inflammatory drugs, primarily diclofenac sodium, etoricoxib, darbufelone mesylate, under the conditions of acute general cooling. The aim of the study: to investigate the effect of non-steroidal anti-inflammatory drugs with various mechanisms of action on the course of the stress reaction, the functional state of the kidneys, liver, and heart using the model of acute general cooling. Materials and Methods: The experiment was carried out using 35 outbreed male rats weighing 256±5 g. The studied drugs were administered intragastrically 30 minutes before cold injury modelling: diclofenac sodium at a dose of 7 mg/kg, etoricoxib at a dose of 5 mg/kg, darbufelone mesylate at a dose of 20 mg/kg. Acute general cooling was induced by exposure at –18 °C for 2 hours. The efficacy of the studied drugs was evaluated by the values as follows: the body temperature (measured rectally), the course of a stress reaction according to the criteria of “the stress triad”, the functional state of the kidney and liver according to the changes in the blood serum biochemical parameters, the functional state of the heart according to the electrocardiogram. Results: It was found that etoricoxib and darbufelone mesylate, and especially diclofenac sodium, demonstrate frigoprotective properties, reducing the severity of hypothermia, have stress-protective activity and a beneficial effect on the functional state of the kidneys. All investigated non-steroidal anti-inflammatory drugs prevent a decrease in myocardial contractility (by the effect on the systolic index) and lengthening of the QT interval caused by acute cold injury. Diclofenac sodium, unlike etoricoxib and darbufelone mesylate, does not enhance the effect of acute general cooling on intraventricular conduction. Under acute exposure to cold, no significant changes in the functional state of the liver were observed, including the groups receiving the nonsteroidal anti-inflammatory medicines. Conclusions: The prophylactic administration of the arachidonic acid cascade inhibitors, especially the non-selective COX-2 inhibitor diclofenac sodium, reduces the severity of the stress response, contributes to the maintenance of the renal and cardiac function. There are no significant changes in the functional state of the liver under conditions of the experimen