Sylwia Fidecka

NMDA/glutamate mechanism of antidepressant-like action of magnesium in forced swim test in mice.

Antidepressant-like activity of magnesium in forced swim test (FST) was demonstrated previously. Also, enhancement of such activity by joint administration of magnesium and antidepressants was shown. However, the mechanism(s) involved in such activity remain to be established. In the present study we examined the involvement of NMDA/glutamate pathway in the magnesium activity in FST in mice. In the present study we investigated the effect of NMDA agonists on magnesium-induced activity in FST and the influence of NMDA antagonists with sub-effective doses of magnesium in this test. Magnesium-induced antidepressant-like activity was antagonized by N-methyl-d-aspartic acid (NMDA). Moreover, low, ineffective doses of NMDA antagonists (CGP 37849, L-701,324, d-cycloserine, and MK-801) administered together with low and ineffective doses of magnesium exhibit significant reduction of immobility time in FST. The active in FST doses of examined agents did not alter the locomotor activity (with an exception of increased activity induced by MK-801). The present study indicates the involvement of NMDA/glutamate pathway in the antidepressant-like activity of magnesium in mouse FST and further suggests antidepressant properties of magnesium.

Enhancement of antidepressant-like activity by joint administration of imipramine and magnesium in the forced swim test: Behavioral and pharmacokinetic studies in mice.

The effect of joint administration of imipramine (IMI) and magnesium (Mg) on antidepressant-like activity was studied in mice using forced swim test (FST). Mg doses ineffective per se (5 and 10 mg/kg) given jointly with IMI also at ineffective doses (10 and 15 mg/kg) resulted in a potent reduction in the immobility time. Since these combined treatments did not influence locomotor activity, the antidepressant-like activity was not due to non-specific behavioral activation. Moreover, we estimated the effect of joint administration of magnesium and IMI in FST on serum and brain magnesium, IMI and its active metabolite desipramine (DMI) concentrations in mice. Swim stress (mice subjected to FST) increased the magnesium concentration in serum and decreased it in the brain compared to naive animals. Moreover administration of IMI increased (normalized) magnesium brain concentration, without influence on the serum level. Joint administration of IMI and magnesium did not influence magnesium (compared with FST) or IMI and DMI (compared with IMI treatment alone) concentrations in both examined tissues. The present data demonstrated an enhancement of the antidepressant-like effect by joint administration of IMI and magnesium in the FST, and further indicate the particular role of magnesium in the antidepressant action. Since there was no increase in IMI, DMI or magnesium concentration after joint administration of magnesium and IMI, the data suggest that pharmacodynamic rather than pharmacokinetic interaction between magnesium and IMI is accountable for behavioral effect in the FST.

Disubstituted thiourea derivatives and their activity on CNS: Synthesis and biological evaluation

A series of new thiourea derivatives of 1,2,4-triazole have been synthesized. The difference in structures of obtained compounds are directly connected with the kind of isothiocyanate (aryl/alkyl). The (1)H NMR, (13)C NMR, MS methods were used to confirm structures of obtained thiourea derivatives. The molecular structure of (1, 17) was determined by an X-ray analysis. Two of the new compounds (8 and 14) were tested for their pharmacological activity on animal central nervous system (CNS) in behavioural animal tests. The results presented in this work indicate the possible involvement of the serotonergic system in the activity of 8 and 14. In the case of 14 is also a possible link between its activity and the endogenous opioid system. All obtained compounds were tested for antibacterial activity against gram-positive cocci, gram-negative rods and antifungal activity. Compounds (1, 2, 5, 7, 9) showed significant inhibition against gram-positive cocci. Microbiological evaluation was carried out over 20 standard strains and 30 hospital strains. Selected compounds (1-13) were examined for cytotoxicity, antitumor, and anti-HIV activity.

Synthesis and pharmacological activity of new carbonyl derivatives of 1 -aryl-2-iminoimidazolidine. Part 2. Synthesis and pharmacological activity of 1,6-diaryl-5,7(1H)dioxo-2,3-dihydroimidazo[1,2-a][1,3,5]triazines

Synthesis and pharmacological activity of 1,6-diaryl-5,7(1H)dioxo-2,3-dihydroimidazo-[1,2-a][1,3,5]triazines (C) are presented. The title compounds were obtained from 1-arylimidazolinurea derivatives in cyclization reaction with difunctional carbonyl reagents--phosgene (method I) or carbonyldiimidazole (CDI) (method II). Their molecular structures were confirmed by the X-ray analysis of 1-phenyl-6-(4-chlorophenyl)-5,7(1H)-dioxo-2,3-dihydroimidazo[1,2-a][1,3,5]triazine (C2) crystals. Compounds C exhibited significant depressive action on the central nervous system (CNS) of the laboratory animals, correlated with very low acute toxicity (LD(50) > 2000 mg kg(-1) i.p.), and showed antinociceptive activity in behavioural models. Reversion of this effect by small dose of naloxone (5 mg kg(-1)) can suggest opioid-like mechanism of antinociception produced by these and other carbonyl derivatives of 1-aryl-2-iminoimidazolidine. Additionally, an effect on the serotonin neurotransmission pathway was also observed. The receptor mechanism of activity for investigated compounds was confirmed only for the opioid mu receptor in binding affinity assay test. Same tests performed for the serotonin 5-HT(2) and benzodiazepine BZD receptors showed no affinity for tested compounds. The opioid-like and serotonergic activities are similar to these described earlier for chain carbonyl 1-aryl-2-iminoimidazolidine derivatives containing urea moiety, mainly due to similar chemical structure, although compounds C are not able to adopt any of the higher energy conformations of urea derivatives. Rigid location of aromatic ring (Ar) at N6, acting as a spacer blocking any direct access to the carbonyl groups (e.g. through the hydrogen bonding), could be responsible for lack of affinity toward 5-HT(2) expressed in the binding assay test.

Pharmacological activity of Salvinorin A, the major component of Salvia divinorum

The hallucinogenic plant Salvia divinorum (i.e., magic mint) is a member of the Sage family that has been historically used for divination and shamanism by the Mazatecs. Today, S. divinorum has become increasingly popular as a recreational drug for its hallucinogenic effects. The non-nitrogenous diterpene, salvinorin A, the major active component of S. divinorum, is responsible for the hallucinogenic effect of this plant. Here, we described the behavioral effects of salvinorin A in animals including the addictive, antinociception and antidepressant properties of the drug. The present paper also demonstrates the not well recognized (or unclear) mechanisms of action of salvinorin A. The last part of the paper presents information about the legal status of S. divinorum and its derivatives. Taking into account the increasing popularity and consumption of salvinorin A and S. divinorum today, it is important to collect all data on the pharmacological profile of this plant and its products.

Synthesis and pharmacological activity of new carbonyl derivatives of 1-aryl-2-iminoimidazolidine: Part 1. Synthesis and pharmacological activity of chain derivatives of 1-aryl-2-iminoimidazolidine containing urea moiety

The synthesis and physicochemical properties of new carbonyl derivatives of 1-aryl-2-iminoimidazolidine are presented. Isomeric 1-(1-arylimidazolidine-2-ylidene)-3-arylureas (series A) and 1-aryl-2-imine-3-arylaminocarbonylimidazolidines (series B) were obtained after the condensation reaction of 1-aryl-2-iminoimidazolidines and arylisocyanates. 1-Aryl-2-iminoimidazolidines were synthesised in a two-step reaction from the respective anilines. The molecular structure of 1-(1-phenylimidazolidine-2-ylidene)-3-(4-chlorophenyl)urea (A2) has been determined by X-ray crystallography. The representatives of both investigated series were evaluated in behavioural animal tests. They exhibited significant, especially analgesic, activity on the animal central nervous system (CNS). They displayed substantial effect on the serotonine and catecholamine neurotransmission as well, at very low toxicity (LD(50) over 2000 mg kg(-1) i.p.). In the binding affinity tests they exhibited moderate affinity (on the micromolar level) toward opioid (mu) and serotonine (5HT(2)) receptors. The derivatives of series A had moderate affinity toward benzodiazepine (BZD) receptor as well. Distinctive differences observed in their activity spectra can be connected with the presence of particular structural features such as relative orientation of the two aromatic rings and the carbonyl moiety.

Synthesis, pharmacological and antiviral activity of 1,3-thiazepine derivatives

The preparation of new fourteen thiourea and fourteen product of their condensation with 1,4-dibromobutane, viz. 1,3-thiazepine derivatives, of 10-isopropyl-8-methyl-4-aza-tricyclo[5.2.2.0(2,6)]undec-8-ene-3,5-dione and 1-isopropyl-7-methyl-4-aza-tricyclo[5.2.2.0(2,6)]undec-8-ene-3,5-dione is described. Elemental analysis, MS and (1)H NMR spectra confirmed the identity of the products. The molecular structure of linear disubstituted thiourea derivative and its cyclization product was determined by an X-ray crystal structure analysis. Two of new obtained compounds (6b and 7a) were tested for their pharmacological activity on animal central nervous system (CNS) in behavioral animal tests. With relatively low acute toxicity (LD(50) lower than 2000 mg kg(-1) i.p.) they exhibited significant influence on spontaneous locomotor activity and body temperature. Additionally, compounds reduced number of the head twitch episodes after 5-hydroksytryptophan (5-HTP) administration. New compounds were evaluated in vitro against representatives of different virus classes, such as a HIV-1 (Retrovirus), a HBV (Hepadnavirus) and the single-stranded RNA(+) viruses Yellow fever virus (YFV) and Bovine viral diarrhea virus (BVDV), both belonging to Flaviridae. Three of new obtained compounds showed a modest activity against HIV-1 wt(IIIB), BVDV and YFV.

Effects of sildenafil treatment on the development of tolerance to diazepam-induced motor impairment and sedation in mice

We studied the effects of sildenafil, a selective inhibitor of PDE5, on the development and the expression of tolerance to diazepam (DZ)-induced motor impairment and sedation in mice. DZ-induced motor incoordination was assessed by the rotarod and chimney tests, and DZ-induced sedation was examined using a photocell apparatus. Sildenafil treatment enhanced the development of tolerance to the motor impairing effects, but not to the sedative effects, of DZ. Sildenafil treatment did not affect the expression of tolerance to DZ-induced motor impairment and sedation in mice. Our results suggest that sildenafil treatment, at least in part, affects the development of DZ tolerance.

Attenuating effect of adenosine receptor agonists on the development of behavioral sensitization induced by sporadic treatment with morphine

The aim of the study is to investigate the effect of adenosine receptor agonists on the development of morphine-induced sensitization to the locomotor activity of mice. Selective A1 (N⁶-cyclopentyladenosine - CPA) and A2A (2-p-(2-carboxyethyl) phenethylamino-5-N-ethylcarboxamidoadenosine hydrochloride - CGS 21680) adenosine receptor agonists or non-selective A1/A2A (5-N-ethylcarboxamidoadenosine - NECA) adenosine agonists as representatives of adenosinergic drugs have been used in the experiment. Behavioral sensitization has been obtained by sporadic treatment with morphine (10.0mg/kg, i.p.). We have shown that adenosine receptor agonists co-administered with morphine significantly attenuates increase in the locomotor activity of mice evoked by challenge dose of morphine. These effects have been observed after stimulation of the selective A1 or A2A and non-selective A1/A2A adenosine receptors, namely both receptors were involved in morphine-induced sensitization. Thus, we have demonstrated that adenosine agonists are able to inhibit behavioral sensitization induced by sporadic applications of morphine.

Adenosine receptor agonists attenuate the development of diazepam withdrawal-induced sensitization in mice

In the present study, the effects of adenosine agonists on the development of sensitization to withdrawal signs precipitated after sporadic treatment with diazepam, in mice, were investigated. To obtain the sensitization, the animals were divided into groups: continuously and sporadically treated with diazepam (15.0 mg/kg, s.c.). The adenosine receptor agonists (CPA, CGS 21,680 and NECA) were administered in sporadically diazepam treated mice during two diazepam-free periods. Concomitant administration of pentetrazole (55.0 mg/kg, s.c.) with flumazenil (5.0 mg/kg, i.p.) after the last injection of diazepam or vehicle, induced the withdrawal signs, such as clonic seizures, tonic convulsion and death episodes. The major finding of our experiments is attenuation of withdrawal signs in sensitized mice, inducing by all adenosine agonists. Only higher dose of CPA produced significantly decreased the number of withdrawal incidents, while both used doses of CGS 21,680 and NECA produced more clear effects. These results support the hypothesis that adenosinergic system is involved in the mechanisms of sensitization to the benzodiazepine withdrawal signs, and adenosine A(2A) receptors play more important role in that process.