Behavioural profile of two potential antidepressant pyridazine derivatives including arylpiperazinyl moieties in their structure, in mice

Novel pyrimido-pyridazine derivatives: design, synthesis, anticancer evaluation and in silico studies

Aim: A novel pyrimido-pyridazine derivative for developing anticancer agents was synthesized via Ullmann arylation using an efficient Cu(OAc)₂ catalyst. Materials & methods: Compounds were investigated for their anticancer potential, against human breast adenocarcinoma cells, viz. MCF-7, MDA-MB-231 and normal cell line HEK-293. Further, an in vivo study was conducted on lymphoma-bearing mice while in silico analysis was carried out for molecular interactions. Results: Compound 2b displayed significant antitumor activity towards MDA-MB-231 cells through induction of apoptosis and arresting cells in S-phase in vitro, while it significantly increased the lifespan and reduced tumor growth in vivo. An in silico study revealed potent tyrosine-protein kinase inhibitors. Conclusion: Taken together the molecule has the potential to become an effective therapeutic treatment for breast cancer.

4-Methylthioamphetamine-induced hyperthermia in mice: influence of serotonergic and catecholaminergic pathways

4-Methylthioamphetamine (4-MTA), also known as p-methylthioamphetamine, is a new amphetamine derivative which in humans has been increasingly associated with severe intoxications and several deaths. As hyperthermia is considered to be one of the most life-threatening acute physiological consequences of amphetamine-related intoxications, it was our aim to determine whether 4-MTA induces changes in body temperature in a mouse model. Accordingly, we measured the subcutaneous temperature after acute administration of 4-MTA in CD1 mice. Because hyperthermia seems to result from the central and peripheral actions of catecholamines and serotonin (5-hydroxytriptamine or 5-HT), we also investigated the possible interactions of some catecholaminergic and serotonergic receptor blockers and the inhibition of monoamine oxidase (MAO) with this effect. 4-MTA induced hyperthermia in CD1 mice. Blockade of the 5-HT receptors with methysergide and MAO inhibition with pargyline resulted in the potentiation of the 4-MTA-induced hyperthermic effect. Blockade of the alpha(1)-adrenergic receptors with prazosin completely reverted the 4-MTA-induced hyperthermia while with the beta-adrenergic receptor blocker dl-propranolol this reversal was not complete. Blockade of the alpha(2)-adrenergic receptors with yohimbine had no effect on the hyperthermia induced by 4-MTA. These results suggest that 4-MTA-induced hyperthermia is highly influenced by the catecholaminergic and serotonergic receptor activation and the MAO activity.

Synthesis of thiazolotriazine derivatives and their antinociceptive effects in mice

Ans raci A series of 2-(4-arylpiperazin-1-yl-methyl)-4-methyl-1-oxo-5,6,8,8a-tetrahydro -thiazolo[3,4-d] [1,2,4]triazines was prepared and tested for antinociceptive activity. The compounds were prepared by the Mannich reaction from the corresponding 2-unsubstituted thiazolotriazines. When administered intraperitoneally most were found to have potent analgesic activity in the mouse during tests of phenylbenzoquinone-induced abdominal constriction; ED50 values (doses resulting in half the maximum effect) ranged from 10 to 87 mg kg(-1). Derivatives with a 3-chloro- or 4-fluorophenylpiperazinylmethyl side-chain in the 2-position of the bicyclic system were, when administered intraperitoneally at doses greater than 25 mg kg(-1), also effective in the hot-plate test without associated sedative effects. The compounds have a large therapeutic index; intraperitoneal LD50 values (doses which result in the death of half the animals) were > 700 mg kg(-1). Naloxone attenuated the analgesic activity of the 3-chloro derivative, suggesting the participation of micro-receptors in the antinociceptive effects of this drug. In addition, a nonopioid mechanism, probably related to enhancement of the release of 5-hydroxytryptamine and noradrenaline, or inhibition of the neuronal re-uptake of these compounds, has been evinced to explain the analgesic properties of the 3-chloro or 4-fluoro derivatives. These results provide evidence for the involvement of noradrenergic and 5-hydroxytryptaminergic pathways in the analgesic activity of 3 and 4. Because of their potential effectiveness, the 3-chloro- or 4-fluorophenylpiperazinylmethyl derivatives might be suitable for treatment of a wide variety of painful conditions and could be attractive reserve agents for patients dissatisfied with opioids.

Effects of two N-arylpiperazinylmethylpyrazolo [1,5-d][1,2,4]triazine derivatives in pain and antidepressant tests in mice

The antinociceptive and antidepressant effects of two pyrazolotriazine derivatives, 2-phenyl-3,3a-dihydro-4-oxo-5-(4-phenylpiperazin-1-yl) methyl-pyrazolo[1,5-d][1,2,4]-triazine (SM1) and 2-phenyl-3,3a-dihydro-4-oxo-5-[4-(4-fluorophenyl)piperazin-1-yl] methylpyrazolo[1,5-d][1,2,4] triazine (SM3) have been investigated in mice using classical pharmacological tests. The intraperitoneal LD50 values of SM1 and SM3 were 253.4 and 218.8 mg kg-1 respectively. SM1 and SM3 showed analgesic properties in the phenylbenzoquinone-induced abdominal constriction test (ED50 approximately 10-15 mg kg-1, i.p.) and in the hot-plate test. The antinociceptive effects of the triazines were significantly reduced by administration of naloxone (1 and 3.2 mg kg-1, s.c.) and yohimbine (1 mg kg-1, p.o.). Acute intraperitoneal administration of both compounds (1 mg kg-1 SM1 or 1.5 mg kg-1 SM3) potentiated morphine (0.15 mg kg-1, s.c.) analgesia in the phenylbenzoquinone test. Although this synergistic activity was not reversed by methysergide (0.5 mg kg-1, i.p.), the analgesic activity of both compounds was enhanced by administration of 5-hydroxytryptophan (50 mg kg-1, i.p.) in conjunction with carbidopa (25 mg kg-1, i.p.). Furthermore, neither compound (at 100 mg kg-1, i.p.) significantly reduced the duration of immobility of mice in the forced swimming test, and both (at 75 mg kg-1, i.p.) were ineffective at enhancing the toxic effects of yohimbine (30 mg kg-1, s.c.). Only SM3 (ED50 = 74.5 mg kg-1, i.p.) significantly antagonized reserpine (2.5 mg kg-1, i.p.)-induced ptosis. Thus, the results suggest that SM1 and SM3 have antinociceptive properties related to co-involvement of opioidergic and alpha 2-adrenoceptor mechanism without associated antidepressant properties.