Receptor Antagonist Activity Research Articles

Design of an innovative nanovehicle to enhance brain permeability of a novel 5-HT6 receptor antagonist

An innovative nanovehicle based on lipid nanocapsules (LNC) was designed to facilitate the passage of a new 5-HT6 receptor antagonist, namely PUC-10, through the blood-brain barrier. PUC-10 is a new synthetic N-arylsulfonylindole that has demonstrated potent 5-HT6 receptor antagonist activity, but it exhibits poor solubility in water, which indicates limited absorption. The lipid nanocapsules designed had a nanometric size (53 nm), a monomodal distribution (PI<0.2), a negative Z potential (−17 ± 7 mV) and allowed efficient PUC-10 encapsulation (74 %). Furthermore, the LNC demonstrated to be stable for at least 4 weeks at 4 °C (storage conditions), for at least 4 h in DMEM at pH 7.4, and for 18 h in water with 5 % DMSO, with both latter conditions maintained at 37 °C. They also demonstrated that cell viability was not affected at the different concentrations studied. Finally, in vitro studies that simulate the blood brain barrier (PAMPA-BBB) demonstrated that the nanoencapsulation of PUC-10 promoted their penetration through the blood-brain barrier, with a calculated permeability of 1.3 × 10−8 cm/s, compared to the null permeability exhibited by non-nanoencapsulated PUC-10.

The use of serotonin type 7 receptor antagonists as a pharmacological intervention in chronic stress. Insights from animal studies

This mini-review presents our current understanding of serotonin type 7 receptor research focusing on the possible network mechanisms underlying the behavioral action of receptor antagonists. The serotonin type 7 receptor is expressed widely throughout the nervous system and known to be involved in various cognitive and physiological mechanisms. It became a clinically significant target after the discovery that its selective antagonist SB 269970 can exert rapid-onset antidepressant effects either alone or in combination with lower doses of conventional antidepressant drugs. Further research has shown that administration of SB 269970 can effectively counteract negative neurobiological outcomes in various chronic stress paradigms. The authors hope they can introduce a wider scientific audience to this promising pharmacological target which, if successful, could in time lead to more discoveries and a better understanding of the underlying serotonin receptor biology as well as its clinical potential. Highlights•The 5-HT7 receptor is widely distributed throughout the nervous system.•5-HT7 receptor antagonist SB 269970 exerts rapid-onset antidepressant effects.•Antidepressant effects of SB 269970 occur via changes in dorsal raphe activity and subsequent cortical serotonin release.

Discovery of Multi-functional Lead Compounds Originating from Traditional Chinese Medicine for Developing Anti-depressive Agents via Virtual Screening

Background: The increasing prevalence of depression has become a global health issue. Currently approved anti-depressive including 5-hydroxytryptamine (5-HT), dopamine (DA), norepinephrine (NE), triple reuptake inhibitors (TRIs) and glutamate N-methyl-D-aspartate (NMDA) receptor antagonists have limited effects because of their insufficient efficacy and/or slow onset of action. Developing multifunctional antidepressants that can modulate 5-HT, DA, NE, and NMDA simultaneously can potentially overcome the current drug defects. Objective: This study aimed to explore leads for the development of multi-functional anti-depressive agents that simultaneous triple reuptake inhibitory and NMDA-GluN2B receptor antagonistic activities. Methods: Potential leads were screened virtually from the TCMSP database based on the 3DPharmacophore model of TRIs followed by the molecular docking into NMDA-GluN2B receptor, BBB score, and the in silico toxicity evaluation. The biological activities of discovered leads on 5-HT, NE, and DA reuptake and their effect on the NMDA-GluN2B receptor were evaluated via radio-labeled neurotransmitters and competition radio-ligand binding experiment with [3H] ifenprodil, respectively. Lastly, the antidepressant effect of these potential leads was determined in vivo through the forced swim test in mice. Results: Two compounds were attained as potential leads after the aforementioned experiments. Further in vitro biological evaluation identified Hit-2 as a promising lead that exerted favorable triple 5- HT/DA/NE reuptake inhibitory activity (66.98% inhibition rate at 10 μM against hNET, 73.01% inhibition rate at 1 μM against hDAT and 86.27% inhibition rate at 1 μM against hSERT), as well as potent NMDA-GluN2B receptor antagonistic activity (Ki=115.73 ± 3.54 nM). The antidepressant activity of Hit- 2 was confirmed through in vivo experiments Conclusion: Hit-2 not only simultaneously inhibited the reuptake of 5-HT, DA, and NE, and acted as an NMDA-GluN2B receptor antagonist in vitro but also showed in vivo antidepressant activity. These findings may serve as a structural basis for the further development of multi-functional anti-depressive agents.

Resolvin E1 as a potential lead for the treatment of depression

Typical monoamine-based antidepressants have significant limitations, including a time lag for therapeutic response and low efficacy (more than one-third of depressed patients fail to respond to multiple antidepressant medications and are considered treatment-resistant). Conversely, ketamine, an N-methyl-D-aspartate receptor antagonist, exhibits rapid and sustained antidepressant actions in patients with treatment-resistant depression. However, clinical use of ketamine is limited due to its serious side effects. Thus, there is a significant need to develop novel ketamine-like antidepressants with fewer side effects. We previously demonstrated that intracerebroventricular infusion of resolvins (RvD1, RvD2, RvE1, RvE2, and RvE3), specialized pro-resolving lipid mediators derived from docosahexaenoic and eicosapentaenoic acids, produce antidepressant-like effects in mouse models of depression. Among resolvins, RvE1 produces the most potent antidepressant-like effects likely via ChemR23 in several mouse models of depression. Local infusion of RvE1 into the medial prefrontal cortex (mPFC) or dorsal hippocampal dentate gyrus (DG) also produces antidepressant-like effects, suggesting that these brain regions are sites of action of RvE1. Additionally, intranasal (i.n.) administration of RvE1 produces antidepressant-like effects through mechanisms similar to ketamine: activity-dependent release of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF), and subsequent mechanistic target of rapamycin complex 1 (mTORC1) activation in the mPFC play a crucial role in the rapid and sustained antidepressant-like actions of i.n. RvE1. Moreover, the antidepressant-like effects of i.n. RvE1 require BDNF and VEGF release, but not mTORC1 activation, in the dorsal DG. These findings suggest that RvE1 can be a promising lead for a novel rapid-acting antidepressant.

Human Biomonitoring of Environmental Chemicals among Elderly in Wuhan, China: Prioritizing Risks Using EPA's ToxCast Database.

In line with the "healthy aging" principle, we aim to assess the exposure map and health risks of environmental chemicals in the elderly. Blood samples from 918 elderly individuals in Wuhan, China, were analyzed using the combined gas/liquid-mass spectrometry technology to detect levels of 118 environmental chemicals. Cluster analysis identified exposure profiles, while risk indexes and bioanalytical equivalence percentages were calculated using EPA's ToxCast database. The detection rates for 87 compounds exceeded 70%. DEHP, DiBP, naphthalene, phenanthrene, DnBP, pyrene, anthracene, permethrin, fluoranthene, and PFOS showed the highest concentrations. Fat-soluble pollutants varied across lifestyles. In cluster 2, which was characterized by higher concentrations of fat-soluble substances, the proportion of smokers or drinkers was higher than that of nonsmokers or nondrinkers. Pesticides emerged as the most active environmental chemicals in peroxisome proliferator-activated receptor gamma antagonist, thyroid hormone receptor (TR) antagonist, TR agonist, and androgen receptor (AR) agonist activity assays. Additionally, PAEs and polycyclic aromatic hydrocarbons played significant roles as active contaminants for the corresponding targets of AR antagonists and estrogen receptor alpha. We proposed a list of priority pollutants linked to endocrine-disrupting toxic effects in the elderly, which may provide the groundwork for further research into environmental etiology.

Thyroid Hormone Receptor Agonistic and Antagonistic Activity of Newly Synthesized Dihydroxylated Polybrominated Diphenyl Ethers: An In Vitro and In Silico Coactivator Recruitment Study.

Dihydroxylated polybrominated diphenyl ethers (DiOH-PBDEs) could be the metabolites of PBDEs of some organisms or the natural products of certain marine bacteria and algae. OH-PBDEs may demonstrate binding affinity to thyroid hormone receptors (TRs) and can disrupt the functioning of the systems modulated by TRs. However, the thyroid hormone disruption mechanism of diOH-PBDEs remains elusive due to the absence of diOH-PBDEs standards. This investigation explores the potential disruptive effects of OH/diOH-PBDEs on thyroid hormones via competitive binding and coactivator recruitment with TRα and TRβ. At levels of 5000 nM and 25,000 nM, 6-OH-BDE-47 demonstrated significant recruitment of steroid receptor coactivator (SRC), whereas none of the diOH-PBDEs exhibited SRC recruitment within the range of 0.32-25,000 nM. AutoDock CrankPep (ADCP) simulations suggest that the conformation of SRC and TR-ligand complexes, particularly their interaction with Helix 12, rather than binding affinity, plays a pivotal role in ligand agonistic activity. 6,6'-diOH-BDE-47 displayed antagonistic activity towards both TRα and TRβ, while the antagonism of 3,5-diOH-BDE-100 for TRα and TRβ was concentration-dependent. 3,5-diOH-BDE-17 and 3,5-diOH-BDE-51 exhibited no discernible agonistic or antagonistic activities. Molecular docking analysis revealed that the binding energy of 3,3',5-triiodo-L-thyronine (T3) surpassed that of OH/diOH-PBDEs. 3,5-diOH-BDE-100 exhibited the highest binding energy, whereas 6,6'-diOH-BDE-47 displayed the lowest. These findings suggest that the structural determinants influencing the agonistic and antagonistic activities of halogen phenols may be more intricate than previously proposed, involving factors beyond high-brominated PBDEs or hydroxyl group and bromine substitutions. It is likely that the agonistic or antagonistic propensities of OH/diOH-PBDEs are instigated by protein conformational changes rather than considerations of binding energy.

In Vitro, In Vivo, and In Silico Analysis of Pyraclostrobin and Cyprodinil and Their Mixture Reveal New Targets and Signaling Mechanisms.

Pyraclostrobin and cyprodinil are broad-spectrum fungicides that are used in crops to control diseases. However, they are excessively used and, as a result, end up in the environment and threaten human health and ecosystems. Hence, knowledge of their mechanisms of action is critical to revealing their environmental fate and negative effects and regulating their use. In the present study, we conducted a comprehensive study to show the adverse effects of pyraclostrobin, cyprodinil, and their mixture using zebrafish larvae and different cell lines. Several end points were investigated, including mortality, development, gene expression, reporter assays, and molecular docking simulations. We found that both compounds and their mixture caused developmental delays and mortality in zebrafish, with a higher effect displayed by pyraclostrobin. Both compounds altered the expression of genes involved in several signaling pathways, including oxidative stress and mitochondrial function, lipid and drug metabolisms, the cell cycle, DNA damage, apoptosis, and inflammation. A noteworthy result of this study is that cyprodinil and the mixture group acted as NFκB activators, while pyraclostrobin demonstrated antagonist activity. The AHR activity was also upregulated by cyprodinil and the mixture group; however, pyraclostrobin did not show any effect. For the first time, we also demonstrated that pyraclostrobin had androgen receptor antagonist activity.

Effect of Mineralocorticoid receptor antagonism (MRA) on aldosterone-interleukin 6 axis in heart failure; second opinion. A case-control study

BackgroundIn cases of heart failure characterized by reduced ejection fraction (HFrEF), heightened levels of aldosterone negatively impact the progression of heart failure. Aldosterone exerts its influence through the activation of mineralocorticoid receptors, leading to the subsequent release of IL-6. Recently, the discovery of the role of mineralocorticoid receptor antagonism (MRA) in managing the progression of heart failure, particularly through its effect on IL-6, prompted its inclusion in the American College of Cardiology guidelines. In the years 2019 and 2021, studies elucidated the proinflammatory role of interleukin 6 in the cytokine storm associated with COVID-19, emphasizing the significance of IL-6 inhibitors in controlling this storm. Further research is required to examine the impact of mineralocorticoid receptor antagonism (MRA) on both aldosterone levels and IL-6 release in patients with HFrEF. Additionally, there is a need to assess the effectiveness of current MRA dosages in controlling heart failure with reduced ejection fraction.Patients and methodsA retrospective analysis was conducted on 108 patients with HFrEF diagnosed through echocardiography. The study covered the period from December 2021 to December 2022. All participants underwent blood tests for aldosterone and interleukin 6 using the ELISA test. The patients were categorized based on cardiac compensation status and the specific mineralocorticoid receptor antagonist (MRA) drug regimen they were on.ResultsThere was a notable rise in aldosterone levels and a reduction in serum IL6 observed in 30 patients with Acute Decompensated Heart Failure (ADHF) who were treated with Mineralocorticoid Receptor Antagonists (MRA), as compared to 30 patients with a similar diagnosis who did not receive MRA. Among 24 patients with compensated heart failure using MRA, there was a significant increase in aldosterone levels and a decrease in IL6, in contrast to 24 patients with compensated heart failure who were not on MRA therapy.ConclusionsIn heart failure with reduced ejection fraction (HFrEF), inhibiting mineralocorticoid receptors leads to a reduction in pro-inflammatory IL-6. The action of Mineralocorticoid Receptor Antagonists (MRA) is deemed safe, well-tolerated, and cost-effective when compared to IL-6 inhibitors. There is a need to reevaluate the current MRA regimen with the objective of enhancing its efficacy for optimal reduction in IL-6 and effective control of heart failure progression.

In-silico Design, ADMET Screening, Prime MM-GBSA Binding Free Energy Calculation and MD Simulation of Some Novel Phenothiazines as 5HT6R Antagonists Targeting Alzheimer's Disease.

Alzheimer's disease is a type of dementia that affects neuronal function, leading to a decline in cognitive functions. Serotonin-6 (5HT6) receptors are implicated in the etiology of neurological diseases. 5HT6 receptor antagonists act as anti-dementia agents. 7YS6 represents a membrane protein, and amplification and overexpression of this protein are associated with Alzheimer's disease. Coumarin-fused phenothiazines are significant anti-Alzheimer's agents due to their inhibitory activity on the Serotonin- 6 receptor. Numerous previously unreported Coumarin-substituted Phenothiazines [A2 to A50] were designed using in-silico methods to evaluate their 5HT6 receptor antagonistic activity. Molecular modeling techniques were employed to study the ligands [A2 to A50] in interaction with the Serotonin-6 receptor (PDB ID: 7YS6) using Schrödinger Suite 2019-4. Molecular modeling studies of the designed ligands [A2 to A50] were conducted using the Glide module. In-silico ADMET screening was performed using the QikProp module, and binding free energy calculations were carried out using the Prime MM-GBSA module within the Schrödinger Suite. The binding affinity of the designed ligands [A2 to A50] towards 5HT6 receptors was determined based on Glide scores. Subsequently, ligand A31 underwent a 100 ns molecular dynamics simulation using the Desmond module of Schrödinger Suite 2020-1, which is based in New York, NY. The majority of the designed ligands exhibited strong hydrogen bonding interactions and hydrophobic associations with the serotonin-6 receptor, which hinder its activity. These ligands achieved remarkable Glide scores within the range of -4.2859 to -7.7128, in comparison to reference standards such as Idalopirdine (-7.78149), Intepirdine (-5.20103), Latrepirdine (-5.54853), and the co-crystallized ligand (-7.02889). In-silico ADMET properties for these ligands fell within the recommended values for drug-likeness. It is worth noting that the MM-GBSA binding free energy of the most potent inhibitor was positive, indicating a strong binding interaction. Additionally, the dynamic behavior of the protein (7YS6)-ligand (A31) complex was studied by subjecting ligand A31 to a 100 ns molecular dynamics simulation. The results of this study reveal strong evidence supporting the potential of coumarin- substituted phenothiazine derivatives as effective Serotonin-6 receptor antagonists. Ligands [A2 to A50], which exhibited noteworthy Glide scores, hold promise for significant anti- Alzheimer activity. Further in-vitro and in-vivo investigations are warranted to explore and confirm their therapeutic potential.

Simultaneous analysis of caffeine and paraxanthine provides potentially useful indexes in the treatment of acute caffeine intoxication.

Caffeine (CFF) is efficiently absorbed after ingestion, and approximately 80% of ingested CFF is metabolized to paraxanthine (PXT). Although PXT has approximately twice the adenosine receptor antagonist activity of CFF, there are few reports measuring the metabolite concentrations during CFF intoxication. Furthermore, no studies have examined the efficacy of hemodialysis (HD) on PXT or the indicators that contribute to treatment strategies for patients with acute CFF intoxication. This study analyzed the association between CFF and PXT blood levels, the blood biochemical data, and the vital signs of 27 cases with information on CFF intake and elapsed time data. It was found that HD was not as effective as CFF against PXT in CFF intoxication; however, HD was effective in cases with relatively high PXT concentrations (>10 μg/mL). Simultaneous analysis of CFF and PXT would make it possible to estimate the time elapsed from CFF intake and the risk of hyperCKemia, which may develop in cases left untreated for a prolonged period after ingestion. Therefore, the measurement of PXT, in addition to CFF, is expected to provide useful information for understanding the pathogenesis of CFF intoxication and the development of treatment strategies of acute CFF intoxication.

Effects of perinatal exposures to a TAML catalyst on the mammary gland and hormone-sensitive outcomes in male mice

Estrogenic chemicals are common pollutants in wastewater and current effluent treatment processes are not typically effective in removing these compounds. Tetra-amido macrocyclic ligands (TAMLs) are catalysts that mimic endogenous peroxidases that may provide a solution to remove environmental pollutants including low concentrations of estrogenic compounds. Yet relatively little is known about the toxicity of TAMLs, and few studies have evaluated whether they may have endocrine disrupting properties. We administered one of three doses of a TAML, NT7, to mice via drinking water throughout pregnancy and lactation. Two pharmacologically active compounds, ethinyl estradiol (EE2) and flutamide were also included to give comparator data for estrogen receptor agonist and androgen receptor antagonist activities. Male pups were evaluated for several outcomes at weaning, puberty, and early adulthood. We found that EE2 exposures during gestation and the perinatal period induced numerous effects that were observed across the three ages including changes to spleen and testis weight and drastic effects on the morphology of the mammary gland. Flutamide had fewer effects but altered anogenital distance at weaning as well as spleen, liver, and kidney weight. In contrast, relatively few effects of NT7 were observed, but included alterations to spleen weight and modest changes to adult testis weight and morphology of the mammary gland at weaning. Collectively, these results provide some of the first evidence suggesting that NT7 may alter some hormone-sensitive outcomes, but that the effects were distinct from either EE2 or flutamide. Additional studies are needed to characterize the biological activity of this and other TAML catalysts.

3D-QSAR and Pharmacophoric study on 2,6-Disubstituted Thiazolo [4,5-b] Pyridines as H3 Receptor Antagonists

Histamine H3 receptor antagonist (H3RA) is a promising therapeutic for CNS disorders including attention deficit hyperactivity disorder [ADHD], sleep disorders, epilepsy, schizophrenia and obesity. 2,6-Disubstituted thiazolo[4,5-b]pyridines reported for their H3 receptor antagonistic activity were selected for three dimensional quantitative structure activity relationship (3D-QSAR) and pharmacophoric study in order to establish structure activity relationship quantitatively and essential structural features. In the current study, VLife Molecular Design Suite software (VlifeMDS) was used for QSAR and biophore studies. Pharmagist (web based server) was used for pharmacophoric study. Partial least square regression (PLSR) analysis showed r2= 0.7902, q2=0.6449 and pred_r2= 0.6650. In this model steric [S_138, S_826] and electrostatic descriptors [E_243, E_652] are involved to play an important role in eliciting biological activity. It showed good internal and external prediction. The contour plots provided further insight of the relationship between structural features of substituted thiazolo[4,5-b]pyridine derivatives and their activities which should be applicable to design newer potential H3R inhibitors. In addition with these studies, pharmacophoric models were also produced using Molsign (VLifeMDS) and Pharmagist (web based server). The identified pharmacophore features are two aromatic and two hydrogen bond acceptor with Molsign whereas common pharmacophoric features with Pharmagist are two aromatic, two hydrophobic and four hydrogen bond acceptors. The present work may be useful for further lead optimization and designing of potent H3 receptor antagonists.

Nitrous oxide for the treatment of complex regional pain syndrome: a randomized blinded trial

IntroductionComplex Regional Pain Syndrome (CRPS) is a debilitating neuropathic condition often refractory to conventional treatments. N-methyl-D-aspartate (NMDA) receptor antagonists have a well-established role in the development and modulation of chronic...

Non-peptide orphanin receptor antagonist activity in rat myocardial ischemia-induced cardiac arrhythmias

One of the causes of sudden cardiac death is arrhythmia after acute myocardial ischemia. After ischemia, endogenous orphanin (N/OFQ) plays a role in the development of arrhythmias. It is discussed in this paper how nonpeptide orphanin receptor (ORL1) antagonists such as J-113397, SB-612111 and compound-24 (C-24) affect arrhythmia in rats following acute myocardial ischemia and what the optimal concentrations for these antagonists are. The electrocardiogram of the rat was recorded as part of the experiment. The concentrations of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in the myocardium were measured following euthanasia. Following the use of three antagonists, we found the lowest inflammatory factor concentrations and the smallest number of ischemic arrhythmia episodes. All of them had a small impact on cardiac function. LF/HF values were significantly reduced in all three antagonist groups, suggesting that they are involved in the regulation of sympathetic nerves. In conclusion, pretreatment with the three antagonist groups can effectively reduce the concentration of TNF-α and IL-1β, and the occurrence of arrhythmias after ischemia can also be significantly reduced. Inflammation and sympathetic activity may be related to the mechanism of action of antagonists.

In vitro, in vivo, and in silico evaluation of the glucocorticoid receptor antagonist activity of 3,6-dibromocarbazole.

3,6-Dibromocarbazole is a novel environmental contaminant which is currently detected in several environmental media worldwide. This work aims to investigate the anti-glucocorticoid potency and endocrine disrupting effects of 3,6-dibromocarbazole. In vitro experiments indicated that 3,6-dibromocarbazole possessed glucocorticoid receptor (GR) antagonistic activity and inhibited dexamethasone-induced GR nuclear translocation. 3,6-Dibromocarbazole reduced the expression levels of glucocorticoid responsive genes including glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), fatty acid synthase (FAS), and tyrosine aminotransferase (TAT), and further disrupted the protein expression of two key enzymes PEPCK and FAS in gluconeogenesis. In vivo experiments showed that 3,6-dibromocarbazole induced abnormal development of zebrafish embryos and disrupted the major neurohormones involved in activation of hypothalamic-pituitary-adrenocortical (HPA) axis in zebrafish larvae. The results of molecular docking and molecular dynamics simulation contributed to explain the antagonistic effect of 3,6-dibromocarbazole. Taken together, this work identified 3,6-dibromocarbazole as a GR antagonist, which might exert endocrine disrupting effects by interfering the pathway of gluconeogenesis.

Discovery of triazole-bridged aryl adamantane analogs as an intriguing class of multifunctional agents for treatment of Alzheimer's disease

Alzheimer's disease (AD) is a progressive brain disorder associated with slow loss of brain functions leading to memory failure and modest changes in behavior. The multifactorial neuropathological condition is due to a depletion of cholinergic neurons and accumulation of amyloid-beta (Aβ) plaques. Recently, a multi-target-directed ligand (MTDL) strategy has emerged as a robust drug discovery tool to overcome current challenges. In this research work, we aimed to design and develop a library of triazole-bridged aryl adamantane analogs for the treatment of AD. All synthesized analogs were characterized and evaluated through various in vitro and in vivo biological studies. The optimal compounds 32 and 33 exhibited potent inhibitory activities against acetylcholinesterase (AChE) (32 - IC50 = 0.086 μM; 33 - 0.135 μM), and significant Aβ aggregation inhibition (20 μM). N-methyl-d-aspartate (NMDA) receptor (GluN1-1b/GluN2B subunit combination) antagonistic activity of compounds 32 and 33 measured upon heterologous expression in Xenopus laevis oocytes showed IC50 values of 3.00 μM and 2.86 μM, respectively. The compounds possessed good blood-brain barrier permeability in the PAMPA assay and were safe for SH-SY5Y neuroblastoma (10 μM) and HEK-293 cell lines (30 μM). Furthermore, in vivo behavioral studies in rats demonstrated that both compounds improved cognitive and spatial memory impairment at a dose of 10 mg/kg oral administration. Together, our findings suggest triazole-bridged aryl adamantane as a promising new scaffold for the development of anti-Alzheimer's drugs.

Impact of pre-spinal atropine on post spinal hemodynamic and cardiac output measured by electrical cardiometry in cesarean delivery, a randomized controlled trial

ABSTRACT Background Spinal anesthesia is a widely used technique for cesarean delivery, but it often results in hypotension, bradycardia, and reduced cardiac output (CO). Atropine has a potent muscarinic receptor antagonist activity in the heart. It may be a good choice to prevent post-spinal bradycardia and minimize the marked CO reduction. Methods Sixty pregnant women between the ages of 18 and 40 who were ASA-PS II and planned for elective cesarean delivery were divided into two equal groups at random. Both groups received spinal anesthesia. Atropine group (I) (n = 30): patients received 0.01 mg/kg atropine, while control group (II) (n = 30): patients received the same volume of saline. CO measured by electrical cardiometry (EC) was the primary outcome where, heart rate (HR), mean blood pressure (MBP), stroke volume (SV), systemic vascular resistance (SVR), and neonatal outcomes were the secondary outcomes. Results CO after the intervention was higher in the atropine (group I) than in the control (group II). Also, CO reduction at 5 and 10 min following spinal anesthesia was less in the group I than in the group II. Except for baseline reading, HR was significantly higher in the atropine group versus the control group. MBP was higher in the atropine group than in the control group in all readings. SV and SVR were similar in both groups. Neonatal outcomes were equivalent in both groups. Conclusion Pre-spinal atropine was effective in preventing post-spinal bradycardia and minimized CO reduction in patients undergoing elective cesarean delivery under spinal anesthesia.

Non-clinical pharmacology and toxicology studies of LPM6690061, a novel 5-hydroxytryptamine (5-HT)2A receptor inverse agonist.

LPM6690061 is a novel compound with 5-HT2A receptor antagonist and inverse agonist activities. To support the clinical trial and marketing application of LPM6690061, a series of pharmacology and toxicology studies have been conducted. In vitro and in vivo pharmacology studies showed that LPM6690061 had high inverse agonism and antagonism activities against human 5-HT2A receptors, and demonstrated significant antipsychotic-like effects in two rat models: the DOI-induced head-twitch model and the MK-801-induced hyperactivity model, which was more effective than the control drug pimavanserin. LPM6690061 did not have detectable side effects on the neurobehavioral activities and respiratory function in rats, or on the ECG or blood pressure in dogs at the doses of 2 and 6mg/kg. The half maximal inhibitory concentration (IC50) of LPM6690061 for inhibiting hERG current was 1.02μM. Three in vivo toxicology studies were conducted. In the single dose toxicity study in rats and dogs, the maximum tolerated dose of LPM6690061 was 100mg/kg. In the 4-week repeat dose toxicity study in rats, the main detectable toxic reactions of LPM6690061 included moderate artery wall hypertrophy, minimal to mild mixed cell inflammation and increased macrophages in the lung, which generally recovered after a 4-week drug withdrawal period. In the 4-week repeat dose toxicity study in dogs, no detectable toxicity was observed. The doses of no-observed-adverse-effect-level (NOAEL) in rats and dogs were 10mg/kg and 20mg/kg, respectively. In conclusion, both in vitro and in vivo pharmacological and toxicological studies showed that LPM6690061 was a safe and efficacious 5-HT2A receptor antagonist/inverse agonist which supports the clinical development as a novel antipsychotic drug.

In Silico Study of the 5-Hydroxytryptamine-2C Receptor Antagonist Activity of Anthocyanins as Antidepressant Therapy

This study aimed to evaluate the drug-likeness, pharmacokinetic and safety prediction of six types of anthocyanins (ANC) as well as virtual molecular interaction between ANC and 5-hydroxytryptamine-2C (5HT-2C) receptor for antagonist target of antidepressant drug development. The Lipinski rule of five was used to predict the oral drug-likeness of ANC. The pharmacokinetic and safety prediction was analyzed with a free accessible web server. The ligands of ANC were retrieved from PubChem National Centre for Biotechnology Information (NCBI) database. The protein of the 5HT-2C receptor was obtained from Protein Data Bank. Molecular docking was performed by PyRx software and visualized using Discovery Studio Software. The results showed ANC is proposed as an oral drug candidate. The pharmacokinetic prediction of ANC was demonstrated to have high absorption in the intestinal route, solubility in the aqueous phase, capability to evade hepatic first-pass metabolism and high total clearance from the kidney. Virtual toxicity prediction showed a higher threshold of chronic lethal dose than control with no toxicity on the salmonella typhimurium reverses mutation assay (AMES) test, liver, and skin. Molecular prediction found ANC type of delphinidin has the most similar interaction site with the control antagonist ligand on the 5HT-2C receptor which is facilitated with hydrogen bonds and hydrophobic bonds at amino residues of Trp324, Phe328, Ala222 and Val135. We concluded ANC particularly delphinidin is proposed as an oral drug candidate potentially used as a 5HT-2C receptor antagonist and thus, further in vitro and in vivo studies are necessary to confirm the effect on antidepressant activity.

Ocimum tenuiflorum extract (HOLIXERTM): Possible effects on hypothalamic-pituitary-adrenal (HPA) axis in modulating stress.

Ocimum tenuiflorum is a sacred medicinal plant bestowed with multiple health benefits. This plant is traditionally considered an adaptogen. Many scientific studies have indicated the anti-stress potential of Ocimum tenuiflorum but with higher doses. The present study investigated the effects of HolixerTM (a clinically studied standardized Ocimum tenuiflorum extract) on modulating stress using two in vivo models, namely the swim endurance study in mice and forced swim test in rats. In addition, we explored the mechanism of action of HolixerTM on the HPA axis using two in vitro cell-based assays to check for its inhibitory effect on cortisol release and CRF1 receptor antagonistic activity. Ocimum tenuiflorum extract enhanced the swimming time in mice, reduced the stress-induced increase in immobility time, and prevented the increase in corticosterone in rats subjected to the forced swim test. Further, Ocimum tenuiflorum extract inhibited cortisol release and exhibited a significant CRF1 receptor antagonist activity. Thus, Ocimum tenuiflorum extract was found effective in managing stress, and the effect could be due to the inhibition of cortisol release and the antagonistic effect on the CRF1 receptors.