First-in-Class Selenium-Containing Potent Serotonin Receptor 5-HT6 Agents with a Beneficial Neuroprotective Profile against Alzheimer's Disease

Alzheimer's disease (AD) has a complex and not-fully-understood etiology. Recently, the serotonin receptor 5-HT6 emerged as a promising target for AD treatment; thus, here a new series of 5-HT6R ligands with a 1,3,5-triazine core and selenoether linkers was explored. Among them, the 2-naphthyl derivatives exhibited strong 5-HT6R affinity and selectivity over 5-HT1AR (13-15), 5-HT7R (14 and 15), and 5-HT2AR (13). Compound 15 displayed high selectivity for 5-HT6R over other central nervous system receptors and exhibited low risk of cardio-, hepato-, and nephrotoxicity and no mutagenicity, indicating its "drug-like" potential. Compound 15 also demonstrated neuroprotection against rotenone-induced neurotoxicity as well as antioxidant and glutathione peroxidase (GPx)-like activity and regulated antioxidant and pro-inflammatory genes and NRF2 nuclear translocation. In rats, 15 showed satisfying pharmacokinetics, penetrated the blood-brain barrier, reversed MK-801-induced memory impairment, and exhibited anxiolytic-like properties. 15's neuroprotective and procognitive-like effects, stronger than those of the approved drug donepezil, may pave the way for the use of selenotriazines to inhibit both causes and symptoms in AD therapy.

Time-dependent cytokines changes in ultra-rush wasp venom immunotherapy

Venom immunotherapy (VIT) represents a potential therapeutic approach for the management of venom allergies, aiming to modify the immune response to venom allergens and enhance its precision. Previous studies have demonstrated that VIT induces a shift in T helper cell responses from Th2 to Th1, characterized by the production of IL-2 and interferon-gamma by CD4+ and CD8+ cells. In order to explore long-term pathways following VIT treatment and verify potential new outcomes, the serum concentrations of 30 cytokines were assessed in a cohort of 61 patients (18 control, 43 study group) exhibiting hypersensitivity to wasp venom. Cytokine levels were measured at 0, 2, 6, and 24 weeks after the initiation phase of VIT in the study group. The present study found no significant alterations in the levels of IL-2 and IFN-γ in the peripheral blood following VIT. However, a noteworthy finding was the substantial increase in the concentration of IL-12, a cytokine capable of promoting the differentiation of Th0 cells into Th1 cells. This observation supports the involvement of the Th1 pathway in the desensitization process induced by VIT. Additionally, the study revealed a significant rise in the levels of IL-9 and TGF-β after VIT. These cytokines may play a role in the generation of inducible regulatory T (Treg) cells, indicating their potential importance in the immune response to venom allergens and the desensitization process associated with VIT. Nevertheless, further investigations are required to comprehend the underlying mechanisms driving the VIT process comprehensively.

KM-408, a novel phenoxyalkyl derivative as a potential anticonvulsant and analgesic compound for the treatment of neuropathic pain

BACKGROUND

Epilepsy frequently coexists with neuropathic pain. Our approach is based on the search for active compounds with multitarget profiles beneficial in terms of potential side effects and on the implementation of screening for potential multidirectional central activity.

METHODS

Compounds were synthesized by means of chemical synthesis. After antiseizure and neurotoxicity screening in vivo, KM-408 and its enantiomers were chosen for analgesic activity evaluations. Further safety studies included acute toxicity in mice, the effect on normal electrocardiogram and on blood pressure in rats, whole body plethysmography in rats, and in vitro and biochemical assays. Pharmacokinetics has been studied in rats after iv and po administration. Metabolism has been studied in vivo in rat serum and urine. Radioligand binding studies were performed as part of the mechanism of action investigation.

RESULTS

Selected results for KM-408: K_i sigma = 7.2*10^-8; K_i 5-HT_1A = 8.0*10^-7; ED₅₀ MES (mice, ip) = 13.3 mg/kg; formalin test (I phase, mice, ip)-active at 30 mg/kg; SNL (rats, ip)-active at 6 mg/kg; STZ-induced pain (mice, ip)-active at 1 mg/kg (von Frey) and 10 mg/kg (hot plate); hot plate test (mice, ip)-active at 30 mg/kg; ED₅₀ capsaicin test (mice, ip) = 18.99 mg/kg; tail immersion test (mice)-active at 0.5%; corneal anesthesia (guinea pigs)-active at 0.125%; infiltration anesthesia (guinea pigs)-active at 0.125%.

CONCLUSIONS

Within the presented study a novel compound, R,S-2-((2-(2-chloro-6-methylphenoxy)ethyl)amino)butan-1-ol hydrochloride (KM-408) with dual antiseizure and analgesic activity has been developed for potential use in neuropathic pain treatment.

Monitoring of tacrolimus concentration after kidney or heart transplantation - the importance of intra-subject variability parameters

Przedmiot badań. Właściwie prowadzona immunosupresja w terapii potransplantacyjnej jest warunkiem niezbędnym do zminimalizowania ryzyka odrzucenia narządu. Cel badań. Analiza stężeń minimalnych (Cssmin) takrolimusu (TAC) w stanie stacjonarnym, w pierwszym miesiącu po przeszczepie serca lub nerki. Wyliczono współczynnik zmienności wewnątrzosobniczej (CV), poszukiwano korelacji z parametrami biochemicznymi oraz przedstawiono zalecenia/aktualne wytyczne optymalizacji dawkowania TAC na podstawie baz medycznych opartych na faktach (EBM). Materiał i metody. Do retrospektywnej analizy wybrano 24 pacjentów w wieku 24-79 lat (średnia 47,1±13,9 lat); 12 po przeszczepie serca i 12 po przeszczepie nerki. Dawkowanie TAC było jednakowe w grupach pacjentów oraz nie ulegało zmianie w trakcie analizy (pierwszy miesiąc); w przypadku biorców serca wynosiło 2 mg/dobę oraz 1 mg/dobę u biorców nerki. Pomiar Cssmin TAC w pełnej krwi (stan stacjonarny) wykonano czterokrotnie u wszystkich pacjentów; pierwszy w 15 dobie leczenia, drugi w 16-18, trzeci w 17-19, czwarty w 18-21. Do analizy stężenia TAC zastosowano test immunologiczny QMS Tacrolimus stosując automatyczny analizator biochemiczny Indiko Plus. Wyniki. Mediana wartości Cssmin TAC wynosiła 6,9-15,6 ng/mL po przeszczepie serca oraz 8,7-16,0 ng/mL po przeszczepie nerki. Zakres CV pacjentów po przeszczepie serca był 4-60%, natomiast po przeszczepie nerki 8-40%. CV>30% (wyższe prawdopodobieństwo ryzyka ostrego odrzucenia) po przeszczepie serca dotyczył 25% pacjentów, po przeszczepie nerki 15%. Analiza przeżycia narządu u biorców serca i nerki wykazała odpowiednio 83% i 100% po średnio 2,7±0,5 i 3,25±2,5 latach od transplantacji. Nie wykazano istotnych korelacji (p > 0,05) pomiędzy CV a wybranymi parametrami biochemicznymi. Wnioski. CV>30% może wskazywać na dużą zmienność w farmakokinetyce TAC, a tym samym konieczność optymalizacji dawkowania/parametrów fizjologicznych wpływających na wartość stężenia. Konieczna wydaje się poprawa personalizacji terapii immunosupresyjnej z TAC, uwzględniająca indywidualne parametry zmienności zewnątrz- i wewnątrzosobniczej w celu uzyskania lepszych efektów oraz uniknięcia ostrego/przewlekłego odrzucenia, przyśpieszonej w czasie utraty przeszczepu i/lub występowania dodatkowych działań niepożądanych TAC.

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.

KM-416, a novel phenoxyalkylaminoalkanol derivative with anticonvulsant properties exerts analgesic, local anesthetic, and antidepressant-like activities. Pharmacodynamic, pharmacokinetic, and forced degradation studies

Anticonvulsant drugs are used to treat a wide range of non-epileptic conditions, including chronic, neuropathic pain. We obtained a phenoxyalkylaminoalkanol derivative, KM-416 which had previously demonstrated a significant anticonvulsant activity and had also been shown to bind to 5-HT_1A, α₂-receptors and SERT and not to exhibit mutagenic properties. As KM-416 is a promising compound in our search for drug candidates, in the present study we further assessed its pharmacological profile (analgesic, local anesthetic, and antidepressant-like activities) accompanied with patch-clamp studies. Considering the importance of drug safety, its influence on the cardiovascular system was also evaluated. Moreover, KM-416 was subjected to forced degradation and pharmacokinetic studies to examine its stability and pharmacokinetic parameters. KM-416 revealed a significant antinociceptive activity in the tonic - the formalin test, neurogenic - the capsaicin test, and neuropathic pain model - streptozotocin-induced peripheral neuropathy. Moreover, it exerted a local anesthetic effect. In addition, KM-416 exhibited anti-depressant like activity. The results from the patch-clamp studies indicated that KM-416 can inhibit currents elicited by activation of NMDA receptors, while it also exhibited a voltage-dependent inhibition of Na⁺ currents. KM-416 did not influence ventricular depolarization and repolarization. Following oral administration, pharmacokinetics of KM-416 was characterized by a rapid absorption in the rat. The brain-to-plasma AUC ratio was 6.7, indicating that KM-416 was well distributed to brain. The forced degradation studies showed that KM-416 was very stable under stress conditions. All these features made KM-416 a promising drug candidate for further development against neuropathic pain and epilepsy.

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.

[Contemporary concepts in studies on cyclic AMP and its role in the inflammatory reaction]

Although cyclic AMP (cAMP) was discovered more than 50 years ago, new reports of unknown functions of this nucleotide still appear in the literature. It is synthesized from adenosine triphosphate in a reaction catalysed by adenylyl cyclase. In mammalian cells nine membrane-associated and one soluble adenylyl cyclase isoforms occur. Most of them interact with Gs- or Gi-protein coupled receptors. The only way of cAMP degradation is the reaction of hydrolysis catalyzed by phosphodiesterase. In humans there are 11 families of these enzymes, which differ in substrate affinity, structure, place of occurrence and mechanism of regulation. Modulation of activity of these enzymes is an important direction in the search for new drugs. The effectors of cAMP are: protein kinase A (PKA), Epac proteins, and cAMP-dependent ion channels. In the course of the inflammatory response, the increase in cAMP level may lead to an increase in IL-10 expression, inhibition of TNF-α, IL-12, and MIP-1β release, as well as to a reduction inthe permeability of blood vessels. In addition, cAMP regulates the process of phagocytosis. In the majority of cases, acting via PKA it induces cell apoptosis, and by activating Epac proteins it inhibits cell death. It has been shown that the levels of cAMP vary in different intracellular spaces due to the discretely positioned proteins responsible for its synthesis and breakdown. Moreover, the enzymatic pathway responsible for the extracellular degradation of cAMP has been discovered. Two transporters, ABCC4 and ABCC5, are involved in the transport of cAMP outside the cells. Administration of drugs modulating the level of this nucleotide to rodents leads to changes in its concentrations in blood and/or animal tissues. Progress in research on cAMP has become possible to a large extent due to the emergence of new analytical methods for the determination of its concentrations in biological material.

Population pharmacokinetic analysis of ciprofloxacin in the elderly patients with lower respiratory tract infections

The aims of the study were to develop a population pharmacokinetic model of ciprofloxacin (CPX) in the elderly patients and to examine the impact of patient-dependent variables on pharmacokinetic parameter values of this drug. The study was conducted in a group of 44 patients at the age of 44-96years, hospitalized due to pneumonia lobaris or bronchopneumonia. Patients received CPX at a dose of 200mg every 12h as a constant rate infusion over 0.5h. Concentrations of CPX in serum were measured by HPLC with UV detection. Population pharmacokinetic analysis revealed that CPX concentration versus time data were best described by a one-compartment model. The mean values of volume of distribution and clearance of CPX in the patients above 65years of age were 78.41±13.17L and 18.39±4.15L/h, respectively. The creatinine clearance influenced CPX clearance according to the equation: CLCPX (L/h)=8.0+0.21·CLCr, while the volume of distribution of CPX was dependent on the body weight of the patient as follows: VdCPX (L)=22.72+0.86·WT. In summary, the developed population model can be used to assess the pharmacokinetic parameters of CPX in the elderly patients and to select on the basis of these parameters and MIC values an optimal dosage regimen of this drug.

Determination of linezolid in human serum by reversed-phase high-performance liquid chromatography with ultraviolet and diode array detection

A high-performance liquid chromatographic (HPLC) method with UV and DAD detection for the quantitative determination of linezolid in human serum was developed in present work. Chromatography was carried out by reversed-phase technique on a RP-18 column with a mobile phase composed of 50 mM phosphate buffer and acetonitrile (76 : 26, v/v), adjusted to pH 3.5 with orthophosphoric acid. Serum samples were deproteinized with methanol centrifuged and then, the supernatant was analyzed using HPLC procedure. No interference was observed at the retention times of linezolid from blank serum or ten commonly used antibiotics. A concentration range from 0.50 to 30.0 g/mL was utilized to construct calibration curves. The lower limit of detection was determined to be 0.1 microg/mL of serum for both detectors. The lower limit of quantification of 0.25 microg/mL (CV = 2.6%) was established for determination using HPLC-UV and 0.5 microg/mL (CV = 5.42%) for HPLC-DAD. The recovery of linezolid was approximately 100%. Intra-day accuracy ranged from 0.97 to 12.63% and 0.74 to 10.85% for HPLC-UV and HPLC-DAD method, respectively. Intra-day precision was less than 4.69% for HPLC-UV and less than 5.42% for HPLC-DAD method. Tests confirmed the stability of linezolid in serum during three freeze-thaw cycles and during long-term storage of frozen serum for up to 6 weeks; in extracts it was stable in the HPLC autosampler over 24 h. Statistical analysis by Student's t-test showed no significant difference between the results obtained by these two methods. In summary, these methods will be used and adapted for infected patients in intensive care unit, to determine linezolid serum concentrations in order to know the pharmacokinetic profiles of linezolid.