Four Novel Synthetic Tryptamine Analogs Induce Head-Twitch Responses and Increase 5-HTR2a in the Prefrontal Cortex in Mice.

Tryptamines are monoamine alkaloids with hallucinogenic properties and are widely abused worldwide. To hasten the regulations of novel substances and predict their abuse potential, we designed and synthesized four novel synthetic tryptamine analogs: Pyrrolidino tryptamine hydrochloride (PYT HCl), Piperidino tryptamine hydrochloride (PIT HCl), N,N-dibutyl tryptamine hydrochloride (DBT HCl), and 2-Methyl tryptamine hydrochloride (2-MT HCl). Then, we evaluated their rewarding and reinforcing effects using the conditioned place preference (CPP) and self-administration (SA) paradigms. We conducted an open field test (OFT) to determine the effects of the novel compounds on locomotor activity. A head-twitch response (HTR) was also performed to characterize their hallucinogenic properties. Lastly, we examined the effects of the compounds on 5-HTR1a and 5-HTR2a in the prefrontal cortex using a quantitative real-time polymerase chain reaction (qRT-PCR) assay. None of the compounds induced CPP in mice or initiated SA in rats. PYT HCl and PIT HCl reduced the locomotor activity and elevated the 5-HTR1a mRNA levels in mice. Acute and repeated treatment with the novel tryptamines elicited HTR in mice. Furthermore, a drug challenge involving a 7-day abstinence from drug use produced higher HTR than acute and repeated treatments. Both the acute treatment and drug challenge increased the 5-HTR2a mRNA levels. Ketanserin blocked the induced HTR. Taken together, the findings suggest that PYT HCl, PIT HCl, DBT HCl, and 2-MT HCl produce hallucinogenic effects via 5-HTR2a stimulation, but may have low abuse potential.

4-MeO-PCP and 3-MeO-PCMo, new dissociative drugs, produce rewarding and reinforcing effects through activation of mesolimbic dopamine pathway and alteration of accumbal CREB, deltaFosB, and BDNF levels.

RATIONALE: A high number of synthetic dissociative drugs continue to be available through online stores, leading to their misuse. Recent inclusions in this category are 4-MeO-PCP and 3-MeO-PCMo, analogs of phencyclidine. Although the dissociative effects of these drugs and their recreational use have been reported, no studies have investigated their abuse potential. OBJECTIVES: To examine their rewarding and reinforcing effects and explore the mechanistic correlations. METHODS: We used conditioned place preference (CPP), self-administration, and locomotor sensitization tests to assess the rewarding and reinforcing effects of the drugs. We explored their mechanism of action by pretreating dopamine receptor (DR) D1 antagonist SCH23390 and DRD2 antagonist haloperidol during CPP test and investigated the effects of 4-MeO-PCP and 3-MeO-PCMo on dopamine-related proteins in the ventral tegmental area and nucleus accumbens. We also measured the levels of dopamine, phosphorylated cyclic-AMP response element-binding (p-CREB) protein, deltaFosB, and brain-derived neurotrophic factor (BDNF) in the nucleus accumbens. Additionally, we examined the effects of both drugs on brain wave activity using electroencephalography. RESULTS: While both 4-MeO-PCP and 3-MeO-PCMo induced CPP and self-administration, only 4-MeO-PCP elicited locomotor sensitization. SCH23390 and haloperidol inhibited the acquisition of drug CPP. 4-MeO-PCP and 3-MeO-PCMo altered the levels of tyrosine hydroxylase, DRD1, DRD2, and dopamine, as well as that of p-CREB, deltaFosB, and BDNF. All drugs increased the delta and gamma wave activity, whereas pretreatment with SCH23390 and haloperidol inhibited it. CONCLUSION: Our results indicate that 4-MeO-PCP and 3-MeO-PCMo induce rewarding and reinforcing effects that are probably mediated by the mesolimbic dopamine system, suggesting an abuse liability in humans.

25B-NBOMe, a novel N-2-methoxybenzyl-phenethylamine (NBOMe) derivative, may induce rewarding and reinforcing effects via a dopaminergic mechanism: Evidence of abuse potential.

An increasing number of N-2-methoxybenzyl-phenethylamine (NBOMe) derivatives are being misused worldwide, including the potent hallucinogen 2-(4-bromo-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25B-NBOMe). However, the number of studies characterizing the abuse potential and psychopharmacological properties of 25B-NBOMe is limited; thus, we examined its rewarding and reinforcing effects using conditioned place preference (CPP) and self-administration (SA) tests. Pretreatment with SCH23390 (SCH), Haloperidol (HAL), and ketanserin (KS), antagonists of dopamine D1 (DRD1 ), dopamine D2 (DRD2 ), and serotonin 2A (5-HT2A receptor) receptors, respectively, was utilized during a CPP test to investigate the involvement of the dopaminergic and serotonergic systems in 25B-NBOMe-mediated effects. We also examined the effects of 25B-NBOMe on the expression of dopamine-related proteins in the nucleus accumbens (NAcc) and ventral tegmental area (VTA). Then, we measured the dopamine level, phosphorylated CREB (p-CREB), deltaFosB (ΔFosB), and brain-derived neurotrophic factor (BDNF) in the NAcc. In addition, we explored the involvement of 5-HT2A receptors in the 25B-NBOMe-induced head twitch response (HTR). We also examined the effects of 25B-NBOMe on brain wave activity using electroencephalography. 25B-NBOMe elicited CPP and SA. SCH and HAL blocked 25B-NBOMe-induced CPP, whereas KS did not. Moreover, 25B-NBOMe altered the DRD1 , DRD2 , and dopamine transporter expression and increased dopamine levels. It also induced changes in p-CREB, ΔFosB, and BDNF expression. 25B-NBOMe induced HTR and increased 5-HT2A receptor mRNA levels, effects inhibited by KS. Furthermore, 25B-NBOMe altered delta and gamma wave activity, which was normalized by SCH and HAL. These findings show that 25B-NBOMe may induce rewarding and reinforcing effects via a dopaminergic mechanism, suggesting its abuse potential.

Repurposing mosloflavone/5,6,7-trimethoxyflavone-resveratrol hybrids: Discovery of novel p38-α MAPK inhibitors as potent interceptors of macrophage-dependent production of proinflammatory mediators.

Herein, we address repurposing hybrids of mosloflavone or 5,6,7-trimethoxyflavone with amide analogs of resveratrol from anticancer leads to novel potent anti-inflammatory chemical entities. To unveil the potent anti-inflammatory molecules, biological evaluations were initiated in LPS-induced RAW 264.7 macrophages at 1 µM concentration. Promising compounds were further evaluated at various concentrations. Multiple proinflammatory mediators were assessed including NO, PGE2, IL-6, TNF-α and IL-1ß. Compound 5z inhibited the induced production of NO, PGE2, IL-6, TNF-α and IL-1ß at the low 1 µM concentration by 44.76, 35.71, 53.48, 29.39 and 41.02%, respectively. Compound 5z elicited IC50 values as low as 2.11 and 0.98 µM against NO and PGE2 production respectively. Compounds 5q and 5g showed potent submicromolar IC50 values of 0.31 and 0.59 µM respectively against PGE2 production. Reverse docking of compound 5z suggested p38-α MAPK, which is a key signaling molecule within the pathways controlling the transcription of proinflammatory mediators, as the molecular target. Biochemical testing confirmed these compounds as p38-α MAPK inhibitors explaining its potent inhibition of proinflammatory mediators' production. Collectively, the results presented 5z as a promising compound for further development of anti-inflammatory agents for treatment of macrophages-and/or immune mediated inflammatory diseases.

The novel methoxetamine analogs N-ethylnorketamine hydrochloride (NENK), 2-MeO-N-ethylketamine hydrochloride (2-MeO-NEK), and 4-MeO-N-ethylketamine hydrochloride (4-MeO-NEK) elicit rapid antidepressant effects via activation of AMPA and 5-HT2 receptors.

RATIONALE: Depressive syndrome or depression is a debilitating brain disorder affecting numerous people worldwide. Although readily available, current antidepressants have low remission rates and late onset times. Recently, N-methyl-D-aspartate (NMDA) receptor antagonists, like ketamine and methoxetamine (MXE), were found to elicit rapid antidepressant effects. As the search for glutamatergic-based antidepressants is increasing, we synthesized three novel MXE analogs, N-ethylnorketamine hydrochloride (NENK), 2-MeO-N-ethylketamine hydrochloride (2-MeO-NEK), and 4-MeO-N-ethylketamine hydrochloride (4-MeO-NEK). OBJECTIVES: To determine whether the three novel MXE analogs induce antidepressant effects and explore their mechanistic correlation. METHODS: We examined their affinity for NMDA receptors through a radioligand binding assay. Mice were treated with each drug (2.5, 5, and 10 mg/kg), and their behavior was assessed 30 min later in the forced swimming test (FST), tail suspension test (TST), elevated plus-maze (EPM) test, and open-field test (OFT). Another group of mice were pretreated with 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline-2,3-dione (NBQX), an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, or ketanserin (KS), a 5-HT2 receptor antagonist, during the FST. We also measured mRNA levels of the AMPA receptor subunits GluA1 and GluA2, brain-derived neurotrophic factor (BDNF), and mammalian target of rapamycin (mTOR) in the hippocampus and prefrontal cortex. RESULTS: The MXE analogs showed affinity to NMDA receptors and decreased immobility time during the FST and TST. NBQX and KS blocked their effects in the FST. The compounds did not induce behavioral alteration during the EPM and OFT. The compounds altered GluA1, GluA2, and BDNF mRNA levels. CONCLUSION: These results suggest that the novel MXE analogs induce antidepressant effects, which is likely via AMPA and 5-HT2 receptor activation.

Natural products hybrids: 3,5,4'-Trimethoxystilbene-5,6,7-trimethoxyflavone chimeric analogs as potential cytotoxic agents against diverse human cancer cells.

Cancer still represents a major global health problem. All currently available anticancer agents have disadvantages like resistance or side effects. Therefore, introduction of novel anticancer agents is needed. Intrigued by the high success rate for natural products-based drug discovery, we designed and synthesized antiproliferative chemical entities as hybrids of two natural products; 3,5,4'-trimethoxystilbene and 5,6,7-trimethoxyflavone. To probe the spectrum of the synthesized compounds, in vitro evaluation was conducted against nine panels representing major cancer diseases. The results revealed the hybrid analogs 4f, 4h, 4k and 4q as promising broad-spectrum anticancer lead compounds eliciting high growth inhibition of several cell lines representing multiple cancers diseases. Evaluation of the promising lead compounds against normal human cell lines suggested a selective cytotoxic effect on cancer cells. Mechanistic investigation of the cytotoxic activity of compound 4f in human cervical cancer HeLa cells showed that it triggers cell death through induction of apoptosis. As a whole, this study presents the natural products hybrid analogs 4f, 4h, 4k and 4q as potential lead compounds for further development of novel anticancer therapeutics.

Antiproliferative 3-deoxysphingomyelin analogs: Design, synthesis, biological evaluation and molecular docking of pyrrolidine-based 3-deoxysphingomyelin analogs as anticancer agents.

Sphingomyelins and glycerophospholipids are structurally related phospholipids. Nevertheless, glycerophospholipids analogs are known as antitumor agents while sphingomyelin analogs were reported as cytoprotective agents. Herein, we have addressed the development of 3-deoxysphingomyelin analogs as cytotoxic agents possessing modified sphingobases. Thus, pyrrolidine-based 3-deoxysphingomyelin analogs were synthesized and evaluated against a panel of cell lines representing four major types of cancers. Compounds 3d, 4d and 6d elicited better GI50 values than the FDA approved drug miltefosine. Investigation of their impact on Akt phosphorylation as a possible mechanism for the antiproliferative activity of this class of compounds revealed that these compounds might elicit a concentration-dependent mechanism via inhibition of Akt phosphorylation at the lower concentration. Molecular docking predicted their binding modes to Akt to involve polar head binding to the Pleckstrin homology domain and hydrophobic tail extension into a hydrophobic pocket connecting the Pleckstrin homology domain and the kinase domain. As a whole, the described work suggests compounds 3d, 4d and 6d as promising pyrrolidine-based 3-deoxysphingomyelin analogs for development of novel cancer therapies.

Design, synthesis and cytotoxicity of chimeric erlotinib-alkylphospholipid hybrids.

Two series of erlotinib-alkylphospholipid hybrids were prepared and evaluated for their antiproliferative activities against a panel of four cell lines representing lung, breast, liver and skin cancers using erlotinib and miltefosine as reference standards. Amide analogs elicited more enhanced cytotoxic activity than analogous esters. Amide derivatives 8d and 8e exhibited promising broad-spectrum antiproliferative activity and higher efficacy than reference erlotinib and miltefosine. Their cellular GI50 values was in the ranges of 24.7-46.9 µM and 26.8-43.1 µM for 8e and 8d respectively. Assay results of the inhibitory activity of the prepared compounds on EGFR kinase reaction and Akt phosphorylation in conjugation with statistical correlation analysis indicated that other mechanisms might contribute to their elicited cytotoxicities. In addition, statistical correlation analysis revealed that mechanisms of elicited cytotoxicities for amide series might be different from ester series. In addition, correlation analysis indicated variations in the mechanisms according to the types of cell line.