Synthesis and Neurotropic Activity of New Heterocyclic Systems: Pyridofuro[3,2-d]pyrrolo[1,2-a]pyrimidines, Pyridofuro[3,2-d]pyrido[1,2-a]pyrimidines and Pyridofuro[3′,2′:4,5]pyrimido[1,2-a]azepines

Background: Neurotic disturbances, anxiety, neurosis-like disorders, and stress situations are widespread. Benzodiazepine tranquillizers have been found to be among the most effective antianxiety drugs. The pharmacological action of benzodiazepines is due to their interaction with the supra-molecular membrane GABA-a-benzodiazepine receptor complex, linked to the Cl-ionophore. Benzodiazepines enhance GABA-ergic transmission and this has led to a study of the role of GABA in anxiety. The search for anxiolytics and anticonvulsive agents has involved glutamate-ergic, 5HT-ergic substances and neuropeptides. However, each of these well-known anxiolytics, anticonvulsants and cognition enhancers (nootropics) has repeatedly been reported to have many adverse side effects, therefore there is an urgent need to search for new drugs able to restore damaged cognitive functions without causing significant adverse reactions. Objective: Considering the relevance of epilepsy diffusion in the world, we have addressed our attention to the discovery of new drugs in this field Thus our aim is the synthesis and study of new compounds with antiepileptic (anticonvulsant) and not only, activity. Methods: For the synthesis of compounds classical organic methods were used and developed. For the evaluation of biological activity some anticonvulsant and psychotropic methods were used. Results: As a result of multistep reactions 26 new, five-membered heterocyclic systems were obtained. PASS prediction of anticonvulsant activity was performed for the whole set of the designed molecules and probability to be active Pa values were ranging from 0.275 to 0.43. The studied compounds exhibit protection against pentylenetetrazole (PTZ) seizures, anti-thiosemicarbazides effect as well as some psychotropic effect. The biological assays evidenced that some of the studied compounds showed a high anticonvulsant activity by antagonism with pentylenetetrazole. The toxicity of compounds is low and they do not induce muscle relaxation in the studied doses. According to the study of psychotropic activity it was found that the selected compounds have an activating behavior and anxiolytic effects on the models of “open field” and “elevated plus maze” (EPM). The data obtained indicate the anxiolytic (anti-anxiety) activity of the derivatives of pyrimidines, especially pronounced in compounds 6n, 6b, and 7c. The studied compounds increase the latent time of first immobilization on the model of “forced swimming” (FST) and exhibit some antidepressant effect similarly to diazepam. Docking studies revealed that compound 6k bound tightly in the active site of GABAA receptor with a value of the scoring function that estimates free energy of binding (ΔG) at −7.95 kcal/mol, while compound 6n showed the best docking score and seems to be dual inhibitor of SERT transporter as well as 5-HT1A receptor. Conclusions: Тhe selected compounds have an anticonvulsant, activating behavior and anxiolytic effects, at the same time exhibit some antidepressant effect.

N-docosahexaenoylethanolamine reduces neuroinflammation and cognitive impairment after mild traumatic brain injury in rats

At present, there is a growing interest in the study of the neurotropic activity of polyunsaturated fatty acids ethanolamides (N-acylethanolamines). N-docosahexaenoylethanolamine (DHEA, synaptamide) is an endogenous metabolite and structural analogue of anandamide, a widely studied endocannabinoid derived from arachidonic acid. The results of this study demonstrate that DHEA, when administered subcutaneously (10 mg/kg/day, 7 days), promotes cognitive recovery in rats subjected to mild traumatic brain injury (mTBI). In the cerebral cortex of experimental animals, we analyzed the dynamics of Iba-1-positive microglia activity changes and the expression of pro-inflammatory markers (IL1β, IL6, CD86). We used immortalized mouse microglial cells (SIM-A9) to assess the effects of DHEA on LPS-induced cytokines/ROS/NO/nitrite, as well as on CD206 (anti-inflammatory microglia) and the antioxidant enzyme superoxide dismutase (SOD) production. In vivo and in vitro experiments showed that DHEA: (1) improves indicators of anxiety and long-term memory; (2) inhibits the pro-inflammatory microglial cells activity; (3) decrease the level of pro-inflammatory cytokines/ROS/NO/nitrites; (4) increase CD206 and SOD production. In general, the results of this study indicate that DHEA has a complex effect on the neuroinflammation processes, which indicates its high therapeutic potential.

Comparison studies of neurotropic activity of the nepeta cataria and nepeta grandiflora extracts

Перспективными источниками биологически активных веществ (БАВ), обладающих нейротропной активностью, являются представители рода Nepeta L. - котовник кошачий (Nepeta cataria L.) и котовник крупноцветковый (Nepeta grandiflora Bieb.). Цель - изучение в эксперименте in vivo и in vitro фармакологической активности экстрактов и фракций БАВ котовника кошачьего и котовника крупноцветкового. Методика. Для сравнительной оценки нейротропной активности экстрактов котовников кошачьего (Nepeta cataria L.) и крупноцветкового (Nepeta grandiflora Bieb.) проведен биологический скрининг образцов, обладающих дофаминергической активностью с применением тирозингидроксилазной специфической ферментной биотест-системы в условиях in vitro. Определение параметров острой токсичности и противовоспалительной активности экстракта проводили в экспериментах in vivo. Для оценки острой токсичности экстракта по методу Кербера использованы белые нелинейные мыши-самцы. Экстракты вводили животным внутрижелудочно в дозах 500, 1000, 1500 и 2000 мг/кг. Изучали влияние курсового (3-4 сут) введения выбранных по результатам скрининга экстрактов (дозы 10 и 100 мг/кг) на центральную нервную систему и поведение животных на моделях «приподнятый крестообразный лабиринт» и «хлоралгидратный сон». Препаратом сравнения служил экстракт пустырника (100 мг/кг). Результаты. В результате проведенных скрининговых исследований в условиях опытов in vitro с применением специфической ферментной биотест-системы на основе тирозингидроксилазы выявлена дофаминергическая активность у котовника крупноцветкового экстракта сухого и котовника кошачьего экстракта сухого. При однократном введении экстракты не приводили к гибели животных, изменению внешнего вида и поведенческих реакций мышей. В соответствии с классификацией токсичности химических веществ по ГОСТ 12.1.007-76 экстракты является малотоксичными веществами. В дозах 10 и 100 мг/кг экстракты оказывали статистически значимое седативное действие, снижали нервно-эмоциональное напряжение. Седативное действие проявлялось в ускорении процесса засыпания и увеличении продолжительности сна. Заключение. Выявлена дофаминергическая активность экстрактов котовника крупноцветкового экстракта сухого и котовника кошачьего экстракта сухого. Экстракты котовника кошачьего и котовника крупноцветкового являются малотоксичными веществами, обладают в опытах in vivo выраженным седативным действием, снижают нервно-эмоциональное напряжение. Экстракты котовника кошачьего и котовника крупноцветкового перспективны для дальнейшего изучения. Promising sources of biologically active substances (BAS) with neurotropic activity are representatives of the genus Nepeta L. - cat’s cat (Nepeta cataria L.) and large-flowered cat’s cat (Nepeta grandiflora Bieb.). The aim of the work is to study the pharmacological activity of extracts and fractions of BAS Catnip and large-flowered Catnip with the use of specific enzyme Biotest systems in in vitro experiments and using biological models on laboratory animals. Method. For a comparative assessment of the neurotropic activity of cat extracts (Nepeta cataria L.) and large-flowered (Nepeta grandiflora Bieb.) biological screening of samples with dopaminergic activity was performed using a tyrosine hydroxylase-specific enzyme Biotest system in in vitro experiments. The parameters of acute toxicity and anti-inflammatory activity of the extract were determined. When studying the acute toxicity of the extract using the Kerber method, white non-linear male mice in the number of 30 individuals were used. Extracts were administered to animals intragastrically in doses of 500, 1000, 1500 and 2000 mg/kg. We studied the effect of course (3-4 days) administration of selected extracts based on the results of screening on the Central nervous system and animal behavior at doses of 10 and 100 mg / kg on the models «raised cruciform labyrinth» and «chloral hydrate sleep». Comparison drug-motherwort extract tablets at a dose of 100 mg/kg. Results. As a result of screening studies in in vitro experiments based on tyrosine hydroxylase, dopaminergic activity was detected in the cat’s large-flowered dry extract and cat’s dry cat extract. When administered once, the extracts did not lead to the death of animals, changes in the appearance and behavioral reactions of mice were not observed. According to the chemical toxicity classification according to GOST 12.1.007-76, extracts are low-toxic substances. In doses of 10 mg / kg and 100 mg / kg, these extracts have a significantly pronounced sedative effect, reduce nervous and emotional tension. The sedative effect is shown in improving sleep and increasing the duration of sleep. Conclusions. Dopaminergic activity was detected in the cat’s large-flowered dry extract and the cat’s dry cat extract. Extracts of Catnip and large-flowered Catnip are low-toxic substances, have a pronounced sedative effect in experiments in vivo, reduce nervous and emotional tension. Extracts of Catnip and large-flowered Catnip are promising for further study.

FEATURES OF BEHAVIORAL STUDY OF LABORATORY ANIMALS DURING EXAMINATION OF SPECIFIC ACTIVITY

The study of behavior and cognitive functions is rather difficult to interpret, is time-consuming and has a number of peculiarities both in planning the study and in conducting the tests themselves. For this kind of experiments, Various biomodels are used for such experiments, but this paper we will focus on experiments on the animals most often used in laboratory practice - small laboratory rodents (rats and mice). Most often, there is a need to carry out psychopharmacological studies in order to examine the specific activity of drugs belonging to the group of psychotropic drugs, however, medicine from other pharmacological groups can also have neurotropic activity and expressly influence the behavior and cognitive functions of both animals and humans. The paper highlights the main stages of planning and conducting a study of behavior and cognitive functions, starting with the analysis of power and calculating the sample size, the formation of experimental groups and ending with the features of data interpretation. It also presents the most commonly used psychopharmacological tests, as well as methods for confirming neurological deficits. Thus, it is possible to highlight a number of points enabling the most accurate determination the spectrum of psychotropic action of the studied drugs: The number of animals in groups should be sufficient for statistical analysis and usually ranges from 12 to 14 per group. When forming groups, it is necessary to type the behavior of animals using the Open Field test or its analogue and create groups of animals identical in behavior. When studying the spectrum of psychotropic action, one should not be limited to one or two narrowly targeted tests, but use a whole range of behavioral tests for the most complete picture of the drug's action. When assessing the effect of the drug in some cases, one should not average the results in a group, but use an assessment of the individual change in behavior of each animal.

Hericerin derivatives from Hericium erinaceus exert BDNF-like neurotrophic activity in central hippocampal neurons and enhance memory

The traditional medicinal mushroom Hericium erinaceus has long been known for enhancing the peripheral nerve regeneration through targeting nerve growth factor (NGF) neurotrophic activity. It was also reported to protect against ageing-dependent cognitive decline in wildtype and in Alzheimer’s disease mouse models suggesting a yet to be defined action on neurons of the central nervous system. Here, we purified and identified biologically active compounds from H. erinaceus, based on their ability to promote neurite outgrowth in hippocampal neurons. N-de phenylethyl isohericerin (NDPIH), an isoindoline compound from this mushroom together with its hydrophobic derivative hericene A, were highly potent in inducing extensive axon outgrowth and neurite branching in the absence of serum demonstrating high neurotropic activity. NDPIH also induced enlarged growth cones suggestive of a brain-derived neurotrophic factor (BDNF)-like activity. Pharmacological inhibition of tropomyosin receptor kinase B (TrkB) by ANA12 prevented NDPIH-induced neurotrophic activity providing evidence that NDPIH acts via TrkB receptors to mediate its neurotrophic effect in central neurons. Finally, in vivo treatment with H. erinaceus crude extract and hericene A significantly increased BDNF and downstream pathway and enhanced learning and memory in the novel object recognition memory test. Our results suggest that hericene A can promote BDNF-like activity in neurons in vitro and in vivo thereby enhancing recognition memory.