Cyproheptadine hydrochloride inhibits African swine fever viral replication in vitro.

African swine fever (ASF) is an infectious disease caused by the African swine fever virus (ASFV), and has a high mortality rate. It has caused serious socioeconomic consequences worldwide. Currently, there are no available commercial vaccines or antiviral drug interventions. D1133L is one of the key genes for ASFV replication and antiviral drug screening. In this study, a virtual screening software program, PyRx, was used to screen libraries of compounds against the potential drug target D1133L. Twelve compounds with a high affinity for ASFV D1133L were screened, and cyproheptadine hydrochloride (periactin) was identified as a candidate drug. The periactin has little cytotoxicity, and which dose-dependently inhibited ASFV replication in vitro. Further research indicated that periactin could significantly down-regulate D1133L at the transcriptional and protein levels with RT-qPCR and western blot methods. This study has provided important candidate drugs for the prevention and treatment of ASF, as well as biological materials and new fields of view for the research and development of vaccines and drugs for ASFV.

D-Optimal mixture design optimization of an HPLC method for simultaneous determination of commonly used antihistaminic parent molecules and their active metabolites in human serum and urine.

This study describes a specific, precise, sensitive and accurate method for simultaneous determination of hydroxyzine, loratadine, terfenadine, rupatadine and their main active metabolites cetirizine, desloratadine and fexofenadine, in serum and urine using meclizine as an internal standard. Solid-phase extraction method for sample clean-up and preconcentration of analytes was carried out using Phenomenex Strata-X-C and Strata X polymeric cartridges. Chromatographic analysis was performed on a Phenomenex cyano (150 × 4.6 mm i.d., 5 µm) analytical column. A D-optimal mixture design methodology was used to evaluate the effect of changes in mobile phase compositions on dependent variables and optimization of the response of interest. The mixture design experiments were performed and results were analyzed. The region of ideal mobile phase composition consisting of acetonitrile-methanol-ammonium acetate buffer (40 mm; pH 3.8 adjusted with acetic acid): 18:36:46% v/v/v was identified by a graphical optimization technique using an overlay plot. While using this optimized condition all analytes were baseline resolved in <10 min. Solvent mixtures were delivered at 1.5 mL/min flow rate and analytes peaks were detected at 222 nm. The proposed bioanalytical method was validated according to US Food and Drug Administration guidelines. The proposed method was sensitive with detection limits of 0.06-0.15 µg/mL in serum and urine samples. Relative standard deviation for inter- and intra-day precision data was found to be <7%. The proposed method may find application in the determination of selected antihistaminic drugs in biological fluids.

The Platelet-Activating Factor Receptor's Association with the Outcome of Ovarian Cancer Patients and Its Experimental Inhibition by Rupatadine.

The platelet-activating factor receptor (PAFR) and its ligand (PAF) are important inflammatory mediators that are overexpressed in ovarian cancer. The receptor is an important player in ovarian cancer development. In this study, we aimed to evaluate the prognostic value of PAFR in epithelial ovarian cancer (EOC) and the potential use of its antagonist, rupatadine, as an experimental treatment. Tissue microarrays of ovarian cancer patients, most markedly those with a non-mucinous subtype, immunohistochemically overexpressed PAFR. Elevated cytoplasmic PAFR expression was found to significantly and independently impair patients' overall and recurrence-free survival (OS: median 83.48 vs. 155.03 months; p = 0.022; RFS: median 164.46 vs. 78.03 months; p = 0.015). In vitro, the serous ovarian cancer subtypes especially displayed an elevated PAFR gene and protein expression. siRNA knockdown of PAFR decreased cell proliferation significantly, thus confirming the receptor's protumorigenic effect on ovarian cancer cells. The clinically approved PAFR antagonist rupatadine effectively inhibited in vitro cell proliferation and migration of ovarian cancer cells. PAFR is a prognostic marker in ovarian cancer patients and its inhibition through rupatadine may have important therapeutic implications in the therapy of ovarian cancer patients.

Identification of new EphA4 inhibitors by virtual screening of FDA-approved drugs.

The receptor tyrosine kinase, erythropoietin-producing hepatocellular A4 (EphA4), was recently identified as a molecular target for Alzheimer's disease (AD). We found that blockade of the interaction of the receptor and its ligands, ephrins, alleviates the disease phenotype in an AD transgenic mouse model, suggesting that targeting EphA4 is a potential approach for developing AD interventions. In this study, we identified five FDA-approved drugs-ergoloid, cyproheptadine, nilotinib, abiraterone, and retapamulin-as potential inhibitors of EphA4 by using an integrated approach combining virtual screening with biochemical and cellular assays. We initially screened a database of FDA-approved drugs using molecular docking against the ligand-binding domain of EphA4. Then, we selected 22 candidate drugs and examined their inhibitory activity towards EphA4. Among them, five drugs inhibited EphA4 clustering induced by ephrin-A in cultured primary neurons. Specifically, nilotinib, a kinase inhibitor, inhibited the binding of EphA4 and ephrin-A at micromolar scale in a dosage-dependent manner. Furthermore, nilotinib inhibited the activation of EphA4 and EphA4-dependent growth cone collapse in cultured hippocampal neurons, demonstrating that the drug exhibits EphA4 inhibitory activity in cellular context. As demonstrated in our combined computational and experimental approaches, repurposing of FDA-approved drugs to inhibit EphA4 may provide an alternative fast-track approach for identifying and developing new treatments for AD.

A preliminary study on efficacy of rupatadine for the treatment of acute dengue infection.

Currently there are no specific treatments available for acute dengue infection. We considered that rupatadine, a platelet-activating factor receptor inhibitor, might modulate dengue-associated vascular leak. The effects of rupatadine were assessed in vitro, and in a dengue model, which showed that rupatadine significantly reduced endothelial permeability by dengue sera in vitro, and significantly inhibited the increased haematocrit in dengue-infected mice with dose-dependency. We conducted a randomised, placebo-controlled trial in 183 adult patients in Sri Lanka with acute dengue, which showed that rupatadine up to 40 mg daily appeared safe and well-tolerated with similar proportions of adverse events with rupatadine and placebo. Although the primary end-point of a significant reduction in fluid leakage (development of pleural effusions or ascites) was not met, post-hoc analyses revealed small but significant differences in several parameters on individual illness days - higher platelet counts and lower aspartate-aminotransferase levels on day 7 in the rupatadine group compared to the placebo group, and smaller effusions on day 8 in the subgroup of patients with pleural effusions. However, due to the small sample size and range of recruitment time, the potential beneficial effects of rupatadine require further evaluation in large studies focused on recruitment during the early febrile phase.

Cyproheptadine and mineralocorticoid effector mechanisms.

Cyproheptadine has recently been reported to blunt the furosemide-induced rise in PRA in normal subjects and to acutely lower plasma aldosterone levels in patients with hyperaldosteronism due to bilateral adrenal hyperplasia; both actions have tentatively been ascribed to the antiserotoninergic action of the drug. We here describe receptor studies showing cyproheptadine to occupy mineralocorticoid, but not glucocorticoid, receptors in rat and mouse kidney. On bioassay, cyproheptadine is a partial mineralocorticoid agonist/predominant antagonist.

Clinical pharmacokinetics of H1-receptor antagonists (the antihistamines).

This article reviews clinical pharmacokinetic data on the H1-receptor antagonists, commonly referred to as the antihistamines. Despite their widespread use over an extended period, relatively little pharmacokinetic data are available for many of these drugs. A number of H1-receptor antagonists have been assayed mainly using radioimmunoassay methods. These have also generally measured metabolites to greater or lesser extents. Thus, the interpretation of such data is complex. After oral administration of H1-receptor antagonists as syrup or tablet formulations, peak plasma concentrations are usually observed after 2 to 3 hours. Bioavailability has not been extensively studied, but is about 0.34 for chlorpheniramine, 0.40 to 0.60 for diphenhydramine, and about 0.25 for promethazine. Most of these drugs are metabolised in the liver, this being very extensive in some instances (e.g. cyproheptadine and terfenadine). Total body clearance in adults is generally in the range of 5 to 12 ml/min/kg (for astemizole, brompheniramine, chlorpheniramine, diphenhydramine, hydroxyzine, promethazine and triprolidine), while their elimination half-lives range from about 3 hours to about 18 days [cinnarizine about 3 hours; diphenhydramine about 4 hours; promethazine 10 to 14 hours; chlorpheniramine 14 to 25 hours; hydroxyzine about 20 hours; brompheniramine about 25 hours; astemizole and its active metabolites about 7 to 20 days (after long term administration); flunarizine about 18 to 20 days]. They also have relatively large apparent volumes of distribution in excess of 4 L/kg. In children, the elimination half-lives of chlorpheniramine and hydroxyzine are shorter than in adults. In patients with alcohol-related liver disease, the elimination half-life of diphenhydramine was increased from 9 to 15 hours, while in patients with chronic renal disease that of chlorpheniramine was very greatly prolonged. Little, if any, published information is available on the pharmacokinetics of these drugs in neonates, pregnancy or during lactation. The relatively long half-lives of a number of the older H1-receptor antagonists such as brompheniramine, chlorpheniramine and hydroxyzine suggest that they can be administered to adults once daily.

Excretion of loratadine in human breast milk.

The excretion of loratadine, a new nonsedating antihistamine, into human breast milk was studied in six lactating nonpregnant volunteers. Each volunteer received one 40-mg loratadine capsule. Milk and blood were collected before and at specified times (to 48 hours) after dosing. Plasma and milk loratadine concentrations were determined by a specific radioimmunoassay, and those of an active but minor metabolite, descarboethoxyloratadine, by high performance liquid chromatography (HPLC). Breast milk concentration-time curves of both loratadine and descarboethoxyloratadine paralleled the plasma concentration-time curves. For loratadine, the plasma Cmax was 30.5 ng/mL at 1.0 hour after dosing and the milk Cmax was 29.2 ng/mL in the 0 to 2 hour collection interval. Through 48 hours, the loratadine milk-plasma AUC ratio was 1.2 and 4.2 micrograms of loratadine was excreted in breast milk, which was 0.010% of the administered dose. For descarboethoxyloratadine, the plasma Cmax was 18.6 ng/mL at 2.2 hours after dosing, whereas the milk Cmax was 16.0 ng/mL, which was in the 4 to 8-hour collection interval. Through 48 hours, the mean milk-plasma descarboethoxyloratadine AUC ratio was 0.8 and a mean of 6.0 micrograms of descarboethoxyloratadine (7.5 micrograms loratadine equivalents) were excreted in the breast milk, or 0.019% of the administered loratadine dose. Thus, a total of 11.7 micrograms loratadine equivalents or 0.029% of the administered dose were excreted as loratadine and its active metabolite. A 4-kg infant ingesting the loratadine and descarboethoxyloratadine excreted would receive a dose equivalent to 0.46% of the loratadine dose received by the mother on a mg/kg basis.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroleptic receptors: stereoselectivity for neuroleptic enantiomers.

In order to identify a pair of neuroleptic enantiomers with the highest stereoselective interaction with neuroleptic/dopamine receptors, the effects of eight pairs of neuroleptic enantiomers were tested on the specific binding of 3H-spiperone to crude homogenates of calf caudate nucleus. The ratios of the Ki values were: (+)-butaclamol/(-)-butaclamol = 3000; dexclamol/(-)-analogue = 151; (+)-isobutaclamol/(-)-isobutaclamol = 146; (-)-CTC/(+)-CTC= 109; (-)-centbutindole/(+)-centbutindole = 20; S(+)-octoclothepin/R(-)-octoclothepin = 11. Thus, the neuroleptic receptor is highly stereoselective for the rigid butaclamol derivatives, but much less so for the flexible neuroleptics. The 3H-apomorphine binding site, however, had a stereoselectivity ratio of only 7 for isobutaclamol, further suggesting that the high affinity sites (i.e. nM) for 3H-neuroleptic binding and for 3H-apomorphine binding are different.

Mu receptor-serotonin link in opioid induced hyperactivity in mice.

Opioid induced locomotor excitation in mice was studied. Both morphine and fentanyl increased spontaneous locomotor activity (SLA). Pentazocine produced a significant inhibition of SLA and also blocked the effects of subsequent morphine and fentanyl, thereby underscoring the importance of mu receptors for the opioid induced enhancement of SLA. Serotonergic receptor blockade with cyproheptadine or depletion with fenfluramine blocked, while uptake blockade with clomipramine potentiated the excitatory effect of fentanyl. Thus a mu receptor-serotonin link for the expression of opioid induced locomotor excitation becomes evident.

Bioavailability of d-pseudoephedrine and azatadine from a repeat action tablet formulation.

The objective of this study was to compare in man the bioavailability of d-pseudoephedrine and azatadine from a repeat action tablet formulation and from conventional tablets. The repeat action tablet, containing 1 mg of azatadine maleate in the coat, and 60 mg of d-pseudoephedrine sulfate in both the coat and the core, was given at 0 hour. A conventional tablet of 60 mg of d-pseudoephedrine sulfate was given at 0 and 4 hours and a conventional tablet of 1 mg of azatadine maleate was given at 0 hour. The plasma levels of d-pseudoephedrine were measured by gas-liquid chromatography and the amount of azatadine in the urine was determined by a mass fragmentographic procedure. The results showed that there were no statistically significant differences in the measured bioavailability parameters (area under plasma concentrations-time curve, maximum plasma concentration and time to reach maximum plasma concentration) for pseudoephedrine from repeat action tablets and conventional d-pseudoephedrine sulfate tablets; neither was there any statistically significant difference in the cumulative urinary excretion of azatadine from the repeat action tablets and conventional azatadine maleate tablets (p less than 0.10). These data clearly demonstrate the bioequivalence of the repeat action tablets and the conventional tablets of d-pseudoephedrine and azatadine.

[Non-sedative antihistaminics and binding to central and peripheral H1 histamine receptors]. / Antihistaminiques non-sédatifs et liaison aux récepteurs histaminergiques-H1 centraux et périphériques.

Four non-sedating antihistamines (astemizole, cetirizine, loratadine and terfenadine) were investigated for in vitro and ex vivo binding to histamine-H1 receptors in guinea-pig cerebellum and lung. In vitro, all the drugs dissociated slowly from H1 receptors (half-times greater than or equal to 100 min), Ki,app-values decreased with longer incubation times for potent lipophylic agents (astemizole and terfenadine) Ki,app-values were lower with more dilute tissue suspensions. In optimized assay conditions astemizole showed a Ki,app-value of 0.2 microM. Terfenadine, cetirizine and loratadine bound with 30-, 80- and 100-times lower affinity to H1 receptors. The occupancy of lung and cerebellar H1 receptors was investigated after oral administration of various dosages of the drugs and at several times after drug administration, using ex vivo binding techniques. Astemizole was a very potent compound showing complete differentiation between lung and cerebellar receptor occupation (with 0.63 mg/kg: 70% of lung H1 receptors were occupied, with less than 10% of cerebellar H1 receptor occupancy). A 7-times higher dose of terfenadine was required to induce the same effect. Astemizole produced a rapid and complete occupancy of lung receptors, which was maintained up to 72 h after administration. In contrast, terfenadine produced a peak effect at 1 h and was completely eliminated from lung receptors in 24 h. Loratadine and cetirizine only poorly differentiated between lung and cerebellar receptor occupancy (at 2.5 mg/kg: 70 and 60% of lung receptor occupancy, 50 and 70% of cerebellar receptor occupancy).(ABSTRACT TRUNCATED AT 250 WORDS)

Binding of agonists and antagonists to mineralocorticoid receptors in human peripheral mononuclear leucocytes.

The binding of agonists (liquorice derivatives) and antagonists (spironolactones and cyproheptadine) to Type I aldosterone binding sites was evaluated in human mononuclear leucocytes and compared with data previously obtained using kidney cytosol or kidney slices from adrenalectomized rats. The affinity of spironolactones (spironolactone and canrenone) is equivalent in all the preparations. In contrast, carbenoxolone and glycyrrhizic acid show no affinity for aldosterone binding sites in mononuclear leucocytes, but bind to receptors in kidney cytosol. The possible explanation of the discrepancies is that, in cytosolic preparations, the two latter compounds may undergo hydrolysis into glycyrrhetinic acid which does possess a measurable affinity for mineralocorticoid receptors in all the preparations.

Life beyond kinases: structure-based discovery of sorafenib as nanomolar antagonist of 5-HT receptors.

Of great interest in recent years has been computationally predicting the novel polypharmacology of drug molecules. Here, we applied an "induced-fit" protocol to improve the homology models of 5-HT(2A) receptor, and we assessed the quality of these models in retrospective virtual screening. Subsequently, we computationally screened the FDA approved drug molecules against the best induced-fit 5-HT(2A) models and chose six top scoring hits for experimental assays. Surprisingly, one well-known kinase inhibitor, sorafenib, has shown unexpected promiscuous 5-HTRs binding affinities, K(i) = 1959, 56, and 417 nM against 5-HT(2A), 5-HT(2B), and 5-HT(2C), respectively. Our preliminary SAR exploration supports the predicted binding mode and further suggests sorafenib to be a novel lead compound for 5HTR ligand discovery. Although it has been well-known that sorafenib produces anticancer effects through targeting multiple kinases, carefully designed experimental studies are desirable to fully understand whether its "off-target" 5-HTR binding activities contribute to its therapeutic efficacy or otherwise undesirable side effects.

A fatality due to cyproheptadine and citalopram.

Cyproheptadine (Periactin) is a first-generation antihistamine available in over-the-counter cold medications and is used to treat allergic-type symptoms. Although antihistamines in general have long been known to cause serious side effects, especially when taken in overdose, few reports that specifically address cyproheptadine-related fatalities exist. A 42-year-old healthy female was found dead at her home with no anatomic cause of death and a recent history of suicidal ideations. Toxicology revealed cyproheptadine and citalopram in the femoral postmortem blood at concentrations of 0.49 and 2.3 mg/L, respectively. Vitreous, urine, and bile analysis were also performed, yielding concentrations of < 0.04 and 0.80 mg/L in the vitreous for cyproheptadine and citalopram, respectively; 0.23 and 8.2 mg/L in the urine; and 30.7 and 9.0 mg/L in the bile. The cause of death was determined to be cyproheptadine and citalopram intoxication, and the manner was ruled a suicide. Although cyproheptadine is widely available in the United States and Europe, there are only two published fatalities due to this antihistamine and only one that specifically cites blood and tissue concentrations. Therefore, this case study will be beneficial to the forensic toxicology community by providing additional information regarding postmortem interpretation.