Lorcaserin: Worthy of Further Insights? Results from Recent Research

New pharmacological approaches in the treatment of schizophrenia

Schizophrenia is a primary health concern, imposing a significant burden on both patients and healthcare systems globally. It is a disease with a complex etiology in which both genetic and environmental factors are involved. Despite numerous studies, the mechanism of its origin is still not fully understood. The hypotheses are synaptic, serotonergic, muscarinic, dopaminergic, microRNA-related, and neurodegenerative theories. Treatment to date is mainly based on antipsychotic drugs that act on the dopaminergic system. Although they are effective in reducing positive symptoms, their effect on negative and cognitive symptoms is limited, and their use is often associated with numerous side effects. A breakthrough in the treatment of schizophrenia came with the approval of the first drug with a non-dopaminergic mechanism of action, which opens up new therapeutic possibilities. As a result, there is intensive research into innovative substances that could increase the effectiveness of treatment and improve the quality of life of patients. In this review, we present the current state of knowledge about schizophrenia, its prevalence, risk factors, and its impact on patients' functioning. We pay special attention to new therapeutic directions, including drugs that affect systems other than the dopaminergic one, which could open up new prospects for treating the condition.

Evaluating bexicaserin for the treatment of developmental epileptic encephalopathies

INTRODUCTION

Developmental epileptic encephalopathies (DEEs) pose significant challenges due to their refractory nature and limited treatment options. Despite advancements in genetic understanding, effective therapies targeting underlying pathophysiology are lacking. Serotoninergic dysfunction has been implicated in epilepsy, sparking interest in serotonin as a therapeutic target.

AREA COVERED

This article explores the potential of bexicaserin, a selective 5-HT2C receptor agonist, as an adjunctive antiseizure medication in DEEs. Bexicaserin is thought to modulate GABAergic neurotransmission, suppressing central hyperexcitability. Preclinical studies demonstrate its efficacy across various seizure models. Clinical trials, including the Pacific Study, reveal promising results in reducing motor seizures. However, challenges such as adverse effects and treatment discontinuation underscore the need for further investigation.

EXPERT OPINION

The efficacy of 5-HT2C serotoninergic agonists, validated in preclinical and clinical studies, highlights serotonin's role in DEEs. Bexicaserin offers new therapeutic possibilities, potentially synergizing with existing antiseizure medications. Polypharmacotherapy, targeting distinct pathways, may enhance therapeutic outcomes. Monitoring pharmacological interactions and addressing central nervous system comorbidities are crucial for optimizing treatment strategies. Further research is needed to elucidate bexicaserin's mechanisms and potential antiepileptogenic effects.

Beyond the 5-HT2A Receptor: Classic and Nonclassic Targets in Psychedelic Drug Action

Serotonergic psychedelics, such as psilocybin and LSD, have garnered significant attention in recent years for their potential therapeutic effects and unique mechanisms of action. These compounds exert their primary effects through activating serotonin 5-HT2A receptors, found predominantly in cortical regions. By interacting with these receptors, serotonergic psychedelics induce alterations in perception, cognition, and emotions, leading to the characteristic psychedelic experience. One of the most crucial aspects of serotonergic psychedelics is their ability to promote neuroplasticity, the formation of new neural connections, and rewire neuronal networks. This neuroplasticity is believed to underlie their therapeutic potential for various mental health conditions, including depression, anxiety, and substance use disorders. In this mini-review, we will discuss how the 5-HT2A receptor activation is just one facet of the complex mechanisms of action of serotonergic psychedelics. They also interact with other serotonin receptor subtypes, such as 5-HT1A and 5-HT2C receptors, and with neurotrophin receptors (e.g., tropomyosin receptor kinase B). These interactions contribute to the complexity of their effects on perception, mood, and cognition. Moreover, as psychedelic research advances, there is an increasing interest in developing nonhallucinogenic derivatives of these drugs to create safer and more targeted medications for psychiatric disorders by removing the hallucinogenic properties while retaining the potential therapeutic benefits. These nonhallucinogenic derivatives would offer patients therapeutic advantages without the intense psychedelic experience, potentially reducing the risks of adverse reactions. Finally, we discuss the potential of psychedelics as substrates for post-translational modification of proteins as part of their mechanism of action.

Regulatory Effect of Electroacupuncture on Hypothalamic Serotonin and its Receptor in Rats with Cerebral Ischemia

BACKGROUND

Previous studies have shown that the neurological damage caused by middle cerebral artery occlusion (MCAO) is not only limited to local infarction but can also cause secondary damage in distant sites, such as the hypothalamus. 5-hydroxytryptamine (5-HT)/ 5-HT transporter (5-HTT) and 5-HT receptor 2A (5-HT2A) are important in the treatment of cerebrovascular diseases.

OBJECTIVE

This study aimed to study the effect of electroacupuncture (EA) on the expression of 5- HT, 5-HTT, and 5-HT2A in the hypothalamus of rats with ischemic brain injury and to explore the protective effect and potential mechanism of EA on the secondary injury of cerebral ischemia.

METHODS

Sprague-Dawley (SD) rats were randomly divided into three groups: sham group, model group, and EA group. The permanent middle cerebral artery occlusion (pMCAO) method was used to induce ischemic stroke in rats. In the EA group, the Baihui (GV20) and Zusanli (ST36) points were selected for treatment, which was administered once per day for two consecutive weeks. The neuroprotective effect of EA was evaluated by nerve defect function scores and Nissl staining. The content of 5-HT in hypothalamus was detected by enzyme linked immunosorbent assay (ELISA), and the expression of 5-HTT and 5-HT2A were detected by Western blot.

RESULTS

Compared with that in the sham group, the nerve defect function score in the model group rats was significantly increased, the hypothalamus tissue showed obvious nerve damage, the levels of 5-HT and the expression of 5-HTT were significantly reduced, and the expression of 5-HT2A was significantly increased. After 2 weeks of EA treatment, the nerve defect function scores of pMCAO rats were significantly reduced, the hypothalamic nerve injury was significantly reduced, the levels of 5-HT and the expression of 5-HTT were significantly increased, and the expression of 5-HT2A was significantly decreased.

CONCLUSION

EA has a certain therapeutic effect on hypothalamic injury secondary to permanent cerebral ischemia, and its potential mechanism may be closely related to the upregulation of 5-HT and 5-HTT expression and the downregulation of 5-HT2A expression.