Multifunctional Arylsulfone and Arylsulfonamide-Based Ligands with Prominent Mood-Modulating Activity and Benign Safety Profile, Targeting Neuropsychiatric Symptoms of Dementia

The current pharmaceutical market lacks therapeutic agents designed to modulate behavioral disturbances associated with dementia. To address this unmet medical need, we designed multifunctional ligands characterized by a nanomolar affinity for clinically relevant targets that are associated with the disease pathology, namely, the 5-HT_2A/6/7 and D₂ receptors. Compounds that exhibited favorable functional efficacy, water solubility, and metabolic stability were selected for more detailed study. Pharmacological profiling revealed that compound 11 exerted pronounced antidepressant activity (MED 0.1 mg/kg), outperforming commonly available antidepressant drugs, while compound 16 elicited a robust anxiolytic activity (MED 1 mg/kg), exceeding comparator anxiolytics. In contrast to the existing psychotropic agents tested, the novel chemotypes did not negatively impact cognition. At a chronic dose regimen (25 days), 11 did not induce significant metabolic or adverse blood pressure disturbances. These promising therapeutic-like activities and benign safety profiles make the novel chemotypes potential treatment options for dementia patients.

Discovery of Novel pERK1/2- or β-Arrestin-Preferring 5-HT1A Receptor-Biased Agonists: Diversified Therapeutic-like versus Side Effect Profile

Novel 1-(1-benzoylpiperidin-4-yl)methanamine derivatives with high affinity and selectivity for serotonin 5-HT_1A receptors were obtained and tested in four functional assays: ERK1/2 phosphorylation, adenylyl cyclase inhibition, calcium mobilization, and β-arrestin recruitment. Compounds 44 and 56 (2-methylaminophenoxyethyl and 2-(1H-indol-4-yloxy)ethyl derivatives, respectively) were selected as biased agonists with highly differential “signaling fingerprints” that translated into distinct in vivo profiles. In vitro, 44 showed biased agonism for ERK1/2 phosphorylation and, in vivo, it preferentially exerted an antidepressant-like effect in the Porsolt forced swimming test in rats. In contrast, compound 56 exhibited a first-in-class profile: it preferentially and potently activated β-arrestin recruitment in vitro and potently elicited lower lip retraction in vivo, a component of “serotonergic syndrome”. Both compounds showed promising developability properties. The presented 5-HT_1A receptor-biased agonists, preferentially targeting various signaling pathways, have the potential to become drug candidates for distinct central nervous system pathologies and possessing accentuated therapeutic activity and reduced side effects.

Novel Aryloxyethyl Derivatives of 1-(1-Benzoylpiperidin-4-yl)methanamine as the Extracellular Regulated Kinases 1/2 (ERK1/2) Phosphorylation-Preferring Serotonin 5-HT1A Receptor-Biased Agonists with Robust Antidepressant-like Activity

Novel 1-(1-benzoylpiperidin-4-yl)methanamine derivatives were designed as "biased agonists" of serotonin 5-HT_1A receptors. The compounds were tested in signal transduction assays (ERK1/2 phosphorylation, cAMP inhibition, Ca²⁺ mobilization, and β-arrestin recruitment) which identified ERK1/2 phosphorylation-preferring aryloxyethyl derivatives. The novel series showed high 5-HT_1A receptor affinity, >1000-fold selectivity versus noradrenergic α₁, dopamine D₂, serotonin 5-HT_2A, histamine H₁, and muscarinic M₁ receptors, and favorable druglike properties (CNS-MPO, Fsp³, LELP). The lead structure, (3-chloro-4-fluorophenyl)(4-fluoro-4-(((2-(pyridin-2-yloxy)ethyl)amino)methyl)piperidin-1-yl)methanone (17, NLX-204), displayed high selectivity in the SafetyScreen44 panel (including hERG channel), high solubility, metabolic stability, and Caco-2 penetration and did not block CYP3A4, CYP2D6 isoenzymes, or P-glycoprotein. Preliminary in vivo studies confirmed its promising pharmacokinetic profile. 17 also robustly stimulated ERK1/2 phosphorylation in rat cortex and showed highly potent (MED = 0.16 mg/kg) and efficacious antidepressant-like activity, totally eliminating immobility in the rat Porsolt test. These data suggest that the present 5-HT_1A receptor-biased agonists could constitute promising antidepressant drug candidates.

Salivary oxidative status in patients with oral lichen planus

Reactive oxygen species (ROS) are involved in the pathogenesis of many inflammatory diseases, including oral lichen planus. Therefore, determining the salivary markers of oxidative stress is an excellent alternative approach to diagnosing oral cavity diseases. The objective of our study was to provide preliminary validation and determination of the salivary markers of oxidative stress in both patients with reticular and erosive forms of oral lichen planus as well as in healthy individuals without any oral lesions. In total, 62 patients with oral lichen planus (OLP) were enrolled in the study, including 31 with the reticular form of lichen planus (44.63 ± 11.05 years) and 31 with erosive forms (40.43 ± 10.05 years), who had never been treated for their disease. The control group comprised 30 individuals without any oral lesions (42.12 ± 12.22 years). We determined the saliva levels in glutathione (GSH), total antioxidant capacity (TAC), and thiobarbituric acid reactive substances (TBARS). The mean saliva levels of GSH and TAC were significantly lower (P < 0.01) in OLP patients compared to the control group. The mean levels of salivary TBARS were higher in both OLP groups (reticular and erosive) compared to the control group (P = 0.01). The lower saliva levels of GSH and TAC in patients with OLP indicate that free radicals and the resulting oxidative damage may play an important role in the pathogenesis of OLP lesions. In conclusion, monitoring the oxidant-antioxidant status of saliva may serve as an efficient and less intrusive marker for determining stages of disease development in patients with OLP.

Evaluation of analgesic, antioxidant, cytotoxic and metabolic effects of pregabalin for the use in neuropathic pain

OBJECTIVE

The aim of this research was to evaluate analgesic, antioxidant, metabolic, and cytotoxic effects of pregabalin (PGB), which is widely applied for the treatment of neuropathic pain syndromes in diabetic patients.

METHODS

We used the streptozotocin (STZ) model of painful diabetic neuropathy (PDN) in mice and we measured the effect of intraperitoneally administered PGB on tactile and thermal nociceptive thresholds in the von Frey and hot plate assays, respectively. The influence of PGB on the motor coordination of diabetic animals was investigated in the rotarod test. In vitro in HepG2 and 3T3-L1 cell lines cytotoxicity of PGB, its influence on glucose utilization, and lipid accumulation were assessed. The antioxidant capacity of PGB was evaluated spectrophotometrically using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method.

RESULTS

Pregabalin was a very efficacious antiallodynic and analgesic drug capable of increasing the pain thresholds for tactile allodynia and thermal hyperalgesia in diabetic mice. In the von Frey test at a dose of 30 mg/kg it elevated the pain threshold for 168% versus diabetic control and in the hot plate test this dose prolonged the latency time to pain reaction for 130% versus control value of diabetic mice. No motor deficits were observed in PGB-treated diabetic animals. In vitro PGB did not influence glucose utilization or lipid accumulation. No antioxidant or cytotoxic effects of PGB were observed at concentrations 1-100 μM.

DISCUSSION AND CONCLUSION

Our experiments demonstrated significant antiallodynic and analgesic properties of PGB in mice. In vitro studies showed that this drug is metabolically neutral. It did not cause motor coordination impairments in diabetic animals either. These effects might be of great importance for diabetic patients.