New approaches to the pathogenesis, clinic, and treatment of hepatic encephalopathy

This review article presents new approaches to the assessment of key pathogenesis factors, clinical features, and treatment of hepatic encephalopathy (HE) associated with liver cirrhosis. Various clinical variants of the course of HE in patients with cirrhosis of the liver areconsidered, which are important for the choice of treatment and prevention of repeated relapses of HE. Analyzed the ammonia hypothesis of pathogenesis and associated hyperammonemia, which is the basis of most modern treatment methods. These data on the activation of the adaptive pathway for removing ammonia in the form of glutamine are used in the further study of drugs that enhance the clearance of ammonia. The possibility of reducing GABA-ergic tone due to the effect of the antagonist on the neurosteroid site in the GABA receptor complex is emphasized.

Напівемпіричний аналіз взаємодії алкоксипохідних 1,4-бенздіазепіну з ГАМКа-рецептором на підставі даних молекулярного докінгу та фармакологічного ефекту

Introduction. Pharmacological spectrum of 1.4-benzodiazepine 3-alkoxy derivatives, in contrast to classical substances, has more prominent analgesic properties, but even among the synthesized and studied molecules there are compounds with different magnitude of this effect.The aim of the study – to evaluate the molecular docking parameters of the theoretically generated structures of 1.4-benzodiazepine alkoxy derivatives with the GABA receptor complex and to compare these data with the pharmacological activity of the synthesized compounds.The molecular docking procedure was carried out using the iGEMDOCK v2.1 program, optimized structures of already synthesized and theoretically designed molecules with differing substituents in the ortho position of the phenyl radical and the "7" position of the condensed system are generated in the Avogadro program (v 1.2.0). The average effective doses of compounds (penthylenetetrazole-induced seizures, 120 mg/kg, subcutaneously 30 min after compounds administration) were studied in white mice.The binding energy of all the generated structures is within the ranges of 81.6–96.8 kcal/mol. Virtual docking data analysis of substituted alkoxy derivatives allows identifying several binding sites inherent for 7-chloro- or 7-bromo-substituted benzodiazepine derivatives. The greatest influence on the binding of chlorine-substituted alkoxy derivatives have regions with a high polarity amino acids (16-23 D) and similar hydrophilicity and hydrophobicity. The contribution of Van der Waals and hydrogen interactions to the total binding energy is determined by the presence of halogen (chlorine or bromine). In penthylenetetrazole-induced seizures test the compounds containing the chlorophenyl substituent in the hetero ring were most active (ED50 (0.42±0.10) μmol/kg for the propyloxy derivative and (0.51±0.17) μmol/kg for the ethyloxy derivative) while for the compounds with the phenyl radical, the ED50 value were much higher (5.1±2.7) μmol/kg and (17.75±1.93) μmol/kg, respectively). The analgesic effect is mainly due to the lkoxy derivatives possibility of binding to a center containing residues of basic amino acids.

Midazolam in Subarachnoid Block: Current Evidence

Midazolam, despite of being the commonest benzodiazepine used in anaesthesia and perioperative care, is a relatively newer addition to the list of adjuvant used in subarachnoid block. Midazolam causes spinally mediated analgesia and the segmental analgesia produced by intrathecal midazolam is mediated by the benzodiazepine-GABA receptor complex. Initial animal studies questioned the safety of intrathecal midazolam in terms of possible neurotoxicity. However subsequent clinical studies also failed to show any neurotoxicity of high dose midazolam even on long-term use. Addition of intrathecal midazolam to bupivacaine significantly improves the duration and quality of spinal anaesthesia and provides prolonged perioperative analgesia without any significant side effects. Clinical studies also reported its safety and efficacy in pregnant women, but some studies also reported mild sedation with intrathecal midazolam. It is also reported to decrease the incidence of PONV. Intrathecal midazolam does not have any clinically significant effect on perioperative hemodynamics.

Synthesis and Anticonvulsant Activity of Various Mannich and Schiff Bases of 1,5-Benzodiazepines

Benzodiazepines have a various behavioral effects in addition to their anxiolytic action. There is every reason to believe that the BZ/GABA receptor complex is involved in these effects, since GABAmimetic manipulations modify the effect of BZ in tests of convulsive activity, motor function, and appetitive behavior. 1,5-Benzodiazepines are biologically important molecules and are extensively used clinically as analgesic, hypnotic, sedative, and antidepressive agents. Hence, 1,5-Benzodiazepines were synthesized by condensation of o-phenylenediamine and ketones, for example, cyclohexanone and acetone in presence of sulfated zirconia (catalyst). Mannich bases were synthesized with acetophenone, p-nitroacetophenone, p-chloroacetophenone, and formaldehyde. Schiff bases were synthesized using Mannich base of 1,5-benzodiazepines with p-chloroaniline and p-chlorophenylsemicarbazide in the presence of glacial acetic acid. All the synthesized compounds were characterized by 1H NMR and IR spectral analyses. All the synthesized derivatives were evaluated at the dose of 30 mg/kg b.w for anticonvulsant activity by isoniazid induced convulsion model, and the compounds NBZD-3 and NBZD-8 were found to be the most active among all compounds. Among all the synthesized derivatives, compounds NBZD-13 and NBZD-17 were found to be the most active among all compounds using thiosemicarbazide induced model. Although NBZD-8, NBZD-10, and NBZD-18 are the compounds which had shown good anticonvulsant activity and have an advantage over that, they were not sedative.