In Vitro and In Vivo Pharmacological Profiles of LENART01, a Dermorphin-Ranatensin Hybrid Peptide

Diverse chemical and pharmacological strategies are currently being explored to minimize the unwanted side effects of currently used opioid analgesics while achieving effective pain relief. The use of multitarget ligands with activity at more than one receptor represents a promising therapeutic approach. We recently reported a bifunctional peptide-based hybrid LENART01 combining dermorphin and ranatensin pharmacophores, which displays activity to the mu-opioid receptor (MOR) and dopamine D2 receptor (D2R) in rat brains and spinal cords. In this study, we investigated the in vitro binding and functional activities to the human MOR and the in vivo pharmacology of LENART01 in mice after subcutaneous administration. In vitro binding assays showed LENART01 to bind and be selective to the human MOR over the other opioid receptor subtypes and delta, kappa and nociceptin receptors. In the [35S]GTPγS binding assay, LENART01 acted as a potent and full agonist to the human MOR. In mice, LENART01 produced dose-dependent antinociceptive effects in formalin-induced inflammatory pain, with increased potency than morphine. Antinociceptive effects were reversed by naloxone, indicating MOR activation in vivo. Behavioral studies also demonstrated LENART01's properties to induce less adverse effects without locomotor dysfunction and withdrawal syndrome compared to conventional opioid analgesics, such as morphine. LENART01 is the first peptide-based MOR-D2R ligand known to date and the first dual MOR-dopamine D2R ligand for which in vivo pharmacology is reported with antinociceptive efficacy and reduced opioid-related side effects. Our current findings may pave the way to new pain therapeutics with limited side effects in acute and chronic use.

Opioid/Dopamine Receptor Binding Studies, NMR and Molecular Dynamics Simulation of LENART01 Chimera, an Opioid-Bombesin-like Peptide

The design and development of hybrid compounds as a new class of drug candidates remains an excellent opportunity to improve the pharmacological properties of drugs (including enzymatic stability, efficacy and pharmacokinetic and pharmacodynamic profiles). In addition, considering various complex diseases and/or disorders, the conjugate chemistry approach is highly acceptable and justified. Opioids have long been recognized as the most potent analgesics and serve as the basic pharmacophore for potent hybrid compounds that may be useful in pain management. However, a risk of tolerance and physical dependence exists. Since dopamine receptors have been implicated in the aforementioned adverse effects of opioids, the construction of a hybrid with dual action at opioid and dopamine receptors is of interest. Herein, we present nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics simulation results for LENART01, an opioid-ranatensin hybrid peptide. Apart from molecular docking, protein-ligand interactions were also assessed in vitro using a receptor binding assay, which proved LENART01 to be bound to mu-opioid and dopamine receptors, respectively.

Bombesins: A New Frontier in Hybrid Compound Development

Recently, bombesin (BN) and its analogs have attracted much attention as excellent anticancer agents because they interact with specific receptors widely distributed on the surface of various cancer cells. However, their biological properties proceed far beyond this, given a broad spectrum of activity. Bombesin receptor ligands are effective drugs for the treatment of rheumatoid arthritis or gastrointestinal diseases. However, most diseases are complex, and the use of polytherapy may lead to pharmacokinetic and pharmacodynamic drug-drug interactions, resulting in side effects. Therefore, there is a need to develop effective compounds that also contain BN or its analogs, which are combined with other structural entities, thus generating a so-called hybrid drug. Hybrid drugs that contain bombesin pharmacophore(s) may be proposed as a solution to the problem of polytherapy or the lack of an effective cure. Such structures have now demonstrated the desired efficacy, though information on these aforementioned compounds is relatively scarce. Therefore, our paper aims to encourage researchers to focus on bombesins. Herein, we indicate that the hybrid approach should also be firmly applied to bombesins and the BN receptor family. This paper's structure is divided into two main sections demonstrating bombesins and their properties, as well as recent data on bombesin-based hybrid compounds and their potential usefulness in medicine. Overall, it refers to the discovery and synthesis of modified bombesin-based hybrid compounds.

Evaluation of Antimicrobial Activities against Various E. coli Strains of a Novel Hybrid Peptide-LENART01

Finding the ideal antimicrobial drug with improved efficacy and a safety profile that eliminates antibiotic resistance caused by pathogens remains a difficult task. Indeed, there is an urgent need for innovation in the design and development of a microbial inhibitor. Given that many promising antimicrobial peptides with excellent broad-spectrum antibacterial properties are secreted by some frog species (e.g., bombesins, opioids, temporins, etc.), our goal was to identify the antimicrobial properties of amphibian-derived dermorphin and ranatensin peptides, which were combined to produce a hybrid compound. This new chimera (named LENART01) was tested for its antimicrobial activity against E. coli strains K12 and R1-R4, which are characterized by differences in lipopolysaccharide (LPS) core oligosaccharide structure. The results showed that LENART01 had superior activity against the R2 and R4 strains compared with the effects of the clinically available antibiotics ciprofloxacin or bleomycin (MIC values). Importantly, the inhibitory effect was not concentration dependent; however, LENART01 showed a time- and dose-dependent hemolytic effect in hemolytic assays.

Air Pollution: A Silent Key Driver of Dementia

In 2017, the Lancet Commission on Dementia Prevention, Intervention, and Care included air pollution in its list of potential risk factors for dementia; in 2018, the Lancet Commission on Pollution concluded that the evidence for a causal relationship between fine particulate matter (PM) and dementia is encouraging. However, few interventions exist to delay or prevent the onset of dementia. Air quality data are becoming increasingly available, and the science underlying the associated health effects is also evolving rapidly. Recent interest in this area has led to the publication of population-based cohort studies, but these studies have used different approaches to identify cases of dementia. The purpose of this article is to review recent evidence describing the association between exposure to air pollution and dementia with special emphasis on fine particulate matter of 2.5 microns or less. We also summarize here the proposed detailed mechanisms by which air pollutants reach the brain and activate the innate immune response. In addition, the article also provides a short overview of existing limitations in the treatment of dementia.

Antipsychotic Drugs Efficacy in Dextromethorphan-Induced Psychosis

Psychosis is known as a broad term of symptoms that cause serious disorganization of behavior, thinking, and perception of reality. One of the medicines that recently gained much attention in terms of its psychotic potential is dextromethorphan (DXM). DXM, a widely used antitussive drug, is a commonly abused drug because of its euphoric, hallucinogenic, and dissociative properties. To date, DXM is a legally marketed cough suppressant that is neither a controlled substance nor a regulated chemical under the Controlled Substances Act. The management of DXM-related psychosis is dependent on the type of psychotic symptoms. Atypical neuroleptics (i.e., olanzapine, risperidone, quetiapine) and typical haloperidol have been used in symptomatic treatment due to their efficacy, especially in positive symptoms (hallucinations and delusions). These agents are also recognized as the preferred option in the symptomatic treatment of DXM-related psychosis due to their better efficacy and safety profile than typical haloperidol in the short-term course. The focus of the present review concerns the current stage of knowledge about DXM psychotic potency as well as the management of DXM-related psychoses with a special emphasis on atypical antipsychotic drugs (i.e., olanzapine, risperidone, quetiapine, and haloperidol).

Relationship between severity of tobacco dependence and personality traits, insomnia and impulsivity in male and female individuals entering alcohol treatment

Introduction

Tobacco dependence (TD) often coexists with alcohol dependence. Previous research documented that both biological and environmental factors influence simultaneous development of the two disorders. However, it has not been determined whether the same psychological and psychopathological factors affect TD in alcohol-dependent males and females.

Aim

The objective of the study was to assess risk factors for high severity of TD in alcohol-dependent individuals considering gender differences.

Methods

The study entailed two groups: male (n = 284) and female (n = 102) subjects entering alcohol addiction treatment programs in Warsaw, Poland. Standardized instruments were used to assess: severity of TD – Fagerstrom Test for Nicotine Dependence, personality traits – NEO-Five Factor Inventory to assess, consequences of drinking – Short Inventory of Problems, impulsivity – Barratt Impulsivity Scale, and Sleep Disorder Questionnaire-7 as a measure of insomnia.

Results

In the studied sample, current smokers comprised 79.1% (n = 225) of male and 79.4% (n = 81) of female participants. Multivariate regression model showed that high negative consequences of drinking (P = 0.001) and low NEO Openness score (P = 0.009) were associated with high risk of TD in female alcoholics (corr. R2 = 0.223; P < 0.0005). Bivariate analyses showed that TD was associated with impulsivity, openness, agreeableness and neuroticism in male alcohol-dependent subjects. Insomnia was the only significant predictor for high severity of TD in the males (corr. R2 = 0.068; P = 0.002).

Conclusions

Different factors contribute to severity of tobacco dependence in male and female alcohol-dependent individuals entering addiction treatment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Relationship between impulsiveness and depressive symptoms in alcohol-dependent patients

Introduction

Impulsiveness is considered to be an important symptom of many psychiatric disorders and is often treated as one of the diagnostic criteria. Relationship between impulsivity and severity of depressive symptoms in alcohol-dependent individuals hasn’t been investigated yet, although both are considered to be important risk factors of relapse.

Objectives

The aim of this study was to analyze relationships between depressive symptoms and level of behavioral as well as cognitive impulsiveness among alcohol-dependent patients.

Methods

By means of Barratt's Impulsiveness Scale and stop-signal task the level of impulsivity among 304 alcohol-dependent patients was measured. Stop-signal task was used as an independent, manipulation-free method of estimating the level of behavioral impulsiveness, and the Barratt's Impulsiveness Scale - as a self report measure of global as well as cognitive impulsivity. Patients were asked to fill in a questionnaire to asses depressive symptoms (BDI, BHS).

Results

The statistical analysis revealed significant association between impulsiveness and severity of depressive symptoms. Individuals with higher scores in BDI scale were more impulsive in Barratt Impulsiveness Scale (r = 0,473; p < 0,0005), whereas patients with higher scores in BHS appeared to be more impulsive in both: stop-signal task (r = 0,21; p = 0,001) and BIS (r = 0,281; p < 0,0005). Depressive symptoms in both measures correlated most with indicators of attention impulsivity in BIS (r = 0,541; p < 0,0005 for BDI and r = 0,312; p < 0,0005 for BHS).

Conclusion

High level of impulsiveness may be treated as an element of depressive disorder in alcohol dependent patients.

Phenomenology and emotional impact of neuropsychiatric symptoms in orthotopic liver transplant for hepatocellular carcinoma

BACKGROUND

Few studies have focused on neuropsychiatric symptoms like hallucinations or delusions occurring in the early posttransplant period. The aim of this study was to estimate the percentage of patients reporting neuropsychiatric symptoms in the immediate postoperative phase, to describe the phenomenology, and to evaluate the emotional impact of such disorders.

METHOD

We studied 94 consecutive patients who underwent orthotopic liver transplant (OLT) for hepatocellular carcinoma at least 30 days prior. The presence of neuropsychiatric symptoms were retrospectively evaluated through a semistructured interview.

RESULTS

Overall 49 patients (52%) reported various postoperative neuropsychiatric symptoms. None of the demographic and clinical variables showed significant associations, except for barbiturate administration; patients using barbiturates showed a lower percentage of neuropsychiatric symptoms. It was a time-limited phenomenon that in most cases resolved by day 7 after transplantation. Interestingly, the most frequent emotion perceived was surprise and not fear; a nontrivial amount of patients reported happiness, while many patients reported no emotion.

CONCLUSIONS

The results of this study suggested the usefulness of a registry of the neurological and psychiatric complications after OLT that may help to clarify the pathogenic mechanisms of such complications and implement uniform protocols of prevention and treatment. In fact, better knowledge of the phenomenology of neuropsychiatric symptoms in OLT recipients could allow easier symptom recognition and therapy adjustments on the basis of the emotional impact of such symptoms on patients, family, and caregivers, as well as increase patients' awareness and capability to face this experience.