Endothelotropic Activity of 4-Hydroxy-3,5-Di-Tret-Butylcinnamic Acid in the Conditions of Experimental Cerebral Ischemia

Correction of Mitochondrial Dysfunction by 4-Hydroxy-3,5-Ditretbutyl Cinnamic Acid in Experimental Alzheimer’s Disease Induced by Aβ Injection in Rats

Background: Alzheimer’s disease is the main form of dementia, which affects more than46 million people every year. In the pathogenesis of Alzheimer’s disease, a significant roleplayed mitochondrial dysfunction, which is a promising pharmacotherapeutic target ofneuroprotective therapy. In this regard, this study aimed to evaluate the effect of the 4-hydroxy-3,5-ditretbutyl cinnamic acid on changes of mitochondrial function in experimental Alzheimer’sdisease induced by Aβ injection in rats. Methods: Alzheimer’s disease was modeled on Wistar rats by injecting a fragment of β-amyloid(Aß 1-42) into the CA1 part of the hippocampus. The test-compound (4-hydroxy-3,5-ditretbutylcinnamic acid, 100 mg/kg, per os) and the reference drugs (resveratrol, 20 mg/kg, per os andEGB671, 100 mg/kg, per os) were administered for 60 days after surgery. The restoration of amemorable trace in animals was evaluated in the Morris water maze test. The concentrationof β -amyloid, Tau-protein, and changes in parameters characterizing mitochondrial function(cellular respiration, concentration of mitochondrial ROS, activity of apoptosis reactions(caspase-3 and apoptosis induced factor) were also determined. Results: This study showed that the administration of 4-hydroxy-3,5-ditretbutyl cinnamic acidat a dose of 100 mg/kg (per os) in rats with reproduced Alzheimer’s disease contributed to thenormalization of mitochondrial respiratory function. It was expressed in the normalizationof aerobic metabolism, increased activity of respiratory complexes and stabilization ofmitochondrial membrane potential. Also, when animals were treated with 4-hydroxy-3,5-ditretbutyl cinnamic acid, there was a decrease in the concentration of intracellular calcium(by 39.7% (p<0.05)), the intensity of apoptosis reactions, and an increase of the latent time ofthe mitochondrial permeability transition pore opening (by 3.8 times (p<0.05)), and decreasesH2O2 concentration (by 21.2% (p<0.05)). Conclusion: In the course of this study, it was found that 4-hydroxy-3,5-ditretbutyl cinnamicacid exceeds the value of neuroprotective action in compared to the reference agents –resveratrol (20 mg/kg) and Ginkgo biloba extract (EGB671, 100 mg/kg).

The Administration of the New Pyrimidine Derivative-4-{2-[2-(3,4-Dimethoxyphenyl)-Vinyl]-6-Ethyl-4-Oxo-5-Phenyl-4H-Pyrimidine-1-Il}Benzsulfamide Restores the Activity of Brain Cells in Experimental Chronic Traumatic Encephalopathy by Maintaining Mitochondrial Function

Background and objectives: To evaluate the effect of a new pyrimidine derivative on the change of mitochondrial function in experimental chronic traumatic encephalopathy. Materials and methods: The study was performed on male mice of the BALB/c line (acute toxicity was assessed) and male rats of the Wistar line, which were modeled chronic traumatic encephalopathy by the method of free fall of the load (weight 150 g from a 50 cm height). The injury to rats was reproduced once a day for 7 days. Further, cognitive functions, changes in sensorimotor deficiency, cerebral blood flow, neuron-specific enolase(NSE), S100β, glial fibrillary acidic protein (GFAP) (in blood serum) and β-amyloid, adenosine triphosphate (ATP) (in brain tissue supernatant) were evaluated. Mitochondrial respiration was also measured. Choline alfoscerate (100 mg/kg) was used as a reference drug. Results: The study found that the use of a new pyrimidine derivative contributed to the preservation of the mitochondrial respirometric function and cognitive functions in rats. In addition, against the administration of test-object marked increase in the concentration of ATP, the velocity of cerebral blood flow was 4.2 times (p < 0.05) and 35.6% (p < 0.05), respectively, as well as reduced concentration and GFAP, NSE, S100β, β-amyloid and sensorimotor deficit at 2.7 (p < 0.05) times; 2 times (p < 0.05); 2.4 times (p < 0.05); of 30.4% (p < 0.05 and 46.5% (p < 0.05), respectively. The LD₅₀ (per os) for the test-object was 4973.56 ± 573.72 mg/kg. Conclusion: Based on the obtained data, high therapeutic efficacy and low systemic toxicity of the application are assumed 4-{2-[2-(3,4-dimethoxyphenyl)-vinyl]-6-ethyl-4-oxo-5-phenyl-4H-pyrimidine-1-Il}benzsulfamide in chronic traumatic encephalopathy.

Mechanism of neuroprotective effect of mGluR4 agonists

Introduction: This review of literature is to demonstrate a role of group III metabotropic glutamate receptors in maintaining the level of extracellular glutamate in ischemic stroke and neurodegenerative diseases.

Metabotropic glutamate receptors: mGluRs are classified into three groups. It is suggested that the activation of mGluR4 may have a neuroprotective effect.

Role of excitotoxicity in the development and severity of various brain diseases: An increase in the concentration of intracellular Ca2+ is the result of excessive accumulation of glutamate in the extracellular space. And a death of nerve cells occurs after a sequence of biochemical reactions, which was called excitotoxicity. It is followed by an imbalance between glutamatergic excitation and GABA-ergic inhibition. As a result of untimely activation of the inhibitory mechanisms, the accumulation of extracellular glutamate, and consequently the death of neurons, continues, which leads to more severe manifestations of the cerebral ischemia.

Role of modulation of mGluRs activity in neuroprotection: The literature describes a large number of studies proving that inhibition of hyperactive glutamatergic transmission has a neuroprotective effect. The most likely mechanisms of neuroprotection are inhibition of glutamate production in the substantia nigra, which in turn protects against glutamate-mediated excitotoxicity, and the reduction of the inflammatory effects.

Anti-inflammatory effect of mGluR4 agonists in the mechanism of neuroprotective action: The astroglial component may contribute to the protective action of mGluR4 modulators, since astrocytes and microglia have mGluR4.

Conclusion: mGluR4 agonists have the neuroprotective and anti-inflammatory effects.

STUDY OF RAPITALAM INFLUENCE ON OXOTREMORINE-INDUCED TREMOR

Parkinson’s disease is the second most common (after Alzheimer’s) neurodegenerative disease. All over the world, there is a search for new drugs aimed at the treatment of Parkinson’s disease. Till up to the present, there is no “ideal” medicine that can completely cure this disease and has minimal adverse side effects. Belgorod research institute of pharmacology of living systems is studying Rapitalam, a new drug for the treatment of tremulous Parkinson’s disease. This is an agonist of the mGluR4 group of metabotropic receptors.

The aim of the article is to study Rapitalam influence on the oxotremorine-induced tremor in rats.

Methods. The study comprised 60 rats (6 groups of 10 males), which were administered intragastrically with the studied substances for 10 days. All the animal groups except Control group 1, were administered with Rapitalam and the reference drug Levodopa. 30 minutes after Rapitalam and Levodopa, they were administered abdominally with the solution of Oxotremorine at the dose of 1.5 mg/kg. The animals of Control group 1, instead of Oxotremorine, were similarly administered with a solvent of 0.9% sodium chloride in the equivalent volume.

Results. In comparison with the reference group, Rapitalam at the dose of 3 mg/kg significantly reduced the severity of tremor 50 min. after its administration. The same effect took place 30 min after the administration of Oxotremorine at the dose of 10 mg/kg. At the dose of 3 and 10 mg/kg, Rapitalam also decreased the number of rats in the group (in %) with the signs of tremor 60 min. and 50 min. after the administration of Oxotremorine, respectively.

Conclusion. The study revealed that Rapitalam has a pronounced anti-tremor effect. Its administration at the studied doses reduced the symptoms of Oxotremorine-induced tremor in rats.