An evaluation of the efficacy of indomethacin in experimentally induced acute sinusitis in rats.

OBJECTIVE: We evaluated how efficacious indomethacin, at two different doses, is in the treatment of an experimental model of sinusitis in rats. MATERIALS AND METHODS: Twenty-one Wistar albino rats (all male) were sorted at random into one of three groups: 1st group (n=7) was placebo. 2nd group (n=7). These rats had sinusitis induced experimentally, following indomethacin 3 mg/kg, 5 days was administered to them. 3rd group (n=7). These rats had sinusitis induced experimentally, following indomethacin 6 mg/kg, 5 days was administered to them. The animals' sinonasal mucosae were examined histopathologically by standard light microscopy. RESULTS: Experimental sinusitis was observed in the 2nd and 3rd groups, but not in the rats administered a placebo. Although the inflammatory features of sinusitis were found to be significantly decreased in the animals administered indomethacin 3 mg/kg (the 2nd group), this anti-inflammatory effect was even greater in the 3rd group, where indomethacin 6 mg/kg had been administered. Indomethacin at either dose was superior to placebo in reducing inflammatory features of sinusitis. CONCLUSIONS: Topical use of indomethacin nasal drops decreased the inflammatory features in experimentally induced acute sinusitis. Moreover, a higher dose of indomethacin (6 mg/kg) was more efficacious than a lower dose (3 mg/kg). The present study is valuable as an initial step in showing the need to undertake human trials to see the effect of indomethacin nasal drops on sinusitis in humans. In acute rhinosinusitis, the use of topical anti-inflammatory drops may help to decrease the symptoms and may be used adjunctively with antibiotic treatment.

The effects and mechanisms of the action of galangin on spatial memory in rats.

BACKGROUND: Galangin, a flavonoid compound with acetylcholinesterase inhibitory activity, may improve cognitive functions by enhancing cholinergic transmission. OBJECTIVES: We aimed to investigate the effects of galangin on spatial memory impairment in rats. METHODS: The effects of galangin (50 and 100 mg/kg) and reference anti-dementia drug donepezil (1mg/kg) administrations were examined on memory impairment induced by the muscarinic cholinergic receptor antagonist scopolamine or the nicotinic cholinergic receptor antagonist mecamylamine in the Morris water maze (MWM) test. Hippocampal acetylcholine concentrations were also determined. RESULTS: Galangin 50 and 100 mg/kg significantly decreased the mean distance to platform and increased the time spent in the escape platform quadrant in scopolamine-treated rats. Galangin 100 mg/kg significantly decreased the mean distance to platform and increased the time spent in the escape platform quadrant in mecamylamine-treated rats. The effects of galangin in the MWM were comparable with donepezil. Scopolamine and mecamylamine decreased acetylcholine concentrations, whereas galangin both alone and with mecamylamine or scopolamine administration increased acetylcholine concentrations. CONCLUSION: Galangin improved memory impairment comparable to donepezil and nicotinic and muscarinic receptors may be involved in this effect. Galangin may be considered as a promising flavonoid in the prevention and treatment of memory impairment in Alzheimer's disease and other dementias (Fig. 7,Ref. 37).

Synthesis and Pharmacology of (Pyridin-2-yl)methanol Derivatives as Novel and Selective Transient Receptor Potential Vanilloid 3 Antagonists.

Transient receptor potential vanilloid 3 (TRPV3) is a Ca(2+)- and Na(+)-permeable channel with a unique expression pattern. TRPV3 is found in both neuronal and non-neuronal tissues, including dorsal root ganglia, spinal cord, and keratinocytes. Recent studies suggest that TRPV3 may play a role in inflammation, pain sensation, and skin disorders. TRPV3 studies have been challenging, in part due to a lack of research tools such as selective antagonists. Herein, we provide the first detailed report on the development of potent and selective TRPV3 antagonists featuring a pyridinyl methanol moiety. Systematic optimization of pharmacological, physicochemical, and ADME properties of original lead 5a resulted in identification of a novel and selective TRPV3 antagonist 74a, which demonstrated a favorable preclinical profile in two different models of neuropathic pain as well as in a reserpine model of central pain.

The Effects of p-nonylphenol on the Myometrial Contractile Activity.

We aimed to investigate the effects and mechanisms of action of p-nonylphenol(p-NP) on uterine contractility in rats. The uterine tissues of female Sprague Dawley rats in diestrus were bathed in isolated organ bath. The effects of vehicle alone (0.1% ethanol), the positive control 17-ß-E2 (10(-5) M) and p-NP (10(-9) M, 10(-8) M, 10(-7) M, 10(-6) M) on spontaneous and KCl-induced uterine contractility of rats were studied. Also, the effects of p-NP in combination with actinomycin D (10(-5) M) (gene transcription inhibitor), cycloheximide (10(-4) M) (protein synthesis inhibitor), fulvestrant (10(-6) M) (pure estrogen receptor antagonist), 2-hydroxy-5-nonanoylbenzamide (10(-3) M) (compound 1b, anti-uterotrophic compound) on spontaneous uterine contractions, and with propranolol (20 µM) (ß-adrenoceptor antagonist) and noradrenaline (5 µM) on KCl (40 mM) induced contractions were investigated. p-NP exhibited a concentration-dependent inhibition on spontaneous uterine contractions. There was no significant difference between the highest p-NP concentration (10(-6) M) and the positive control 17-ß-E2 in terms of % inhibition (p>0.05). The inhibitory effect of p-NP (10(-6) M) on spontaneous contractions was blocked by actinomycin D (p<0.001), cycloheximide (p<0.001), fulvestrant (p<0.001) and compound 1b (p<0.001). 17-ß-E2 (10(-5) M) exerted a higher inhibition % on KCl induced contractions than p-NP (10(-6) M). The relaxant effect of p-NP on KCl-induced uterine contractions was inhibited by noradrenaline (p<0.05) but not by propranolol (p>0.05). We suggest that p-NP inhibited uterine contractions similar as 17-ß-E2 and genomic pathways are involved and ß-adrenoceptors might modulate the activity of p-NP. In addition, compound 1b showed an uterotonic activity and reversed the effect of p-NP.

Discovery of (R)-1-(7-chloro-2,2-bis(fluoromethyl)chroman-4-yl)-3-(3-methylisoquinolin-5-yl)urea (A-1165442): a temperature-neutral transient receptor potential vanilloid-1 (TRPV1) antagonist with analgesic efficacy.

The synthesis and characterization of a series of selective, orally bioavailable 1-(chroman-4-yl)urea TRPV1 antagonists is described. Whereas first-generation antagonists that inhibit all modes of TRPV1 activation can elicit hyperthermia, the compounds disclosed herein do not elevate core body temperature in preclinical models and only partially block acid activation of TRPV1. Advancing the SAR of this series led to the eventual identification of (R)-1-(7-chloro-2,2-bis(fluoromethyl)chroman-4-yl)-3-(3-methylisoquinolin-5-yl)urea (A-1165442, 52), an analogue that possesses excellent pharmacological selectivity, has a favorable pharmacokinetic profile, and demonstrates good efficacy against osteoarthritis pain in rodents.

Synthesis and monoamine oxidase inhibitory activities of some 3-(4-fluorophenyl)-5-aryl-n-substituted-4,5-dihydro-(1H)-pyrazole-1-carbothioamide derivatives.

28 new 3-(4-fluorophenyl)-5-aryl-N-substituted-4,5-dihydro-1H-pyrazole-1-carbothioamide derivatives were synthesized and evaluated in vitro for their monoamine oxidase (MAO) A and B inhibitory activity and selectivity. The derivatives substituted by halogen on the fifth position of pyrazole ring, inhibited MAO-A enzyme with a high selectivity index. On the other hand, compounds substituted with 2-naphthyl inhibited MAO-B enzyme with a moderate selectivity index. Docking studies were done to highlight the interactions of the most active derivative with the active site of MAO-A. In addition, in vivo antidepressant and anxiolytic activities of the compounds having selective MAO-A inhibitory effects, were investigated by using Porsolt forced swimming and elevated plus-maze tests respectively. 3-(4-Fluorophenyl)-5-(4-chloro-phenyl)-N-allyl-4,5-dihydro-1H-pyrazole-1-carbothio-amide has antidepressant, 3-(4-fluorophenyl)-5-(4-chlorophenyl)-N-methyl-4,5-dihydro-1H-pyrazole-1-carbothioamide and 3-(4-fluoro-phenyl)-5-(4-bromophenyl)-N-ethyl-4,5-dihydro-1H-pyrazole-1-carbothioamide have anxiolytic activity.

Warfarin dose requirement in Turkish patients: the influences of patient characteristics and polymorphisms in CYP2C9, VKORC1 and factor VII.

BACKGROUND: To determine the contribution of cytochrome P4502C9 (CYP2C9), vitamin K epoxide reductase (VKORC1) and factor VII genotypes, age, body mass index (BMI), international normalized ratio (INR) and other individual patient characteristics on warfarin dose requirements in an adult Turkish population. METHODS: Blood samples were collected from 101 Turkish patients. Genetic analyses for CYP2C9*2 and *3, VKORC1 -1639 G>A and factor VII -401 G>T polymorphisms were performed. Age, INR, BMI values and other individual patient characteristics were also recorded. RESULTS: The mean daily warfarin dosage was significantly higher in patients with the CYP2C9*1/*1 genotype than in the CYP2C9*2/*2 and CYP2C9*1/*3 groups (p ≤ 0.05). With respect to the VKORC1 -1639 G>A polymorphism, the mean warfarin daily dose requirement was higher in the wild type group compared to the heterozygous group (p≤0.001). The mean daily dose requirement for patients with the GG form of factor VII was significantly higher than that of patients with the TT genotype (p ≤ 0.05). Age, gender, BMI, INR had no statistically significant correlation with warfarin dose (p ≥ 0.05). CONCLUSIONS: Polymorphisms in CYP2C9, VKORC1 and factor VII did partially affect daily warfarin dose requirements, while age, gender, BMI and INR do not. However, further case-control studies with a larger study size and different genetic loci are needed to confirm our study.

Microwave-assisted synthesis and spasmolytic activity of 4-indolylhexahydroquinoline derivatives.

In the present study a microwave-assisted one-pot method was applied for the synthesis of 18 novel condensed 1,4-dihydropyridines carrying the indole moiety. The compounds were achieved by the reaction of appropriate 1,3-cyclohexanedione, substituted indole carboxaldehyde derivative, alkyl acetoacetate and ammonium acetate in methanol, according to a modified Hantzsch reaction. The structure elucidation of the compounds was carried out by spectral methods including X-ray studies. Their spasmolytic activities through calcium channel blockade were assayed on isolated rat ileum. The obtained results indicated that the introduction of the brom atom on the indole ring altered the mentioned activity positively.

Microwave-assisted synthesis of 1,3-benzothiazol-2(3H)-one derivatives and analysis of their antinociceptive activity.

A rapid and efficient method was developed for synthesis of 6-acyl-1,3-benzothiazol-2(3H)-one derivatives under microwave irradiation (MWI) conditions. The reaction times were shortened compared to conventional heating. Additionally, we synthesized acetic acid and acetamide derivatives of 1,3-benzothiazol-2(3H)-one, 6-acyl-1,3-benzothiazol-2(3H)-one, 5-chloro-1,3-benzothiazol-2(3H)-one and 6-acyl-5-chloro-1,3-benzothiazol-2(3H)-one with the microwave-assisted method and analyzed their antinociceptive activity with the tail flick, tail clip, hot plate and writhing tests. Among the synthesized compounds, 3-[2-(4-ethylpiperazin-1-yl)-2-oxoethyl]-1,3-benzothiazol-2(3H)-one (6a), 5-chloro-3-{2-oxo-2-[4-(propan-2-yl) piperazin-1-yl]ethyl}-1,3-benzothiazol-2(3H)-one (7e) and 3-[2-(4-butylpiperazin-1-yl)-2-oxoethyl]-5-chloro-1,3-benzothiazol-2(3H)-one (8e) showed significant antinociceptive activity in the tail clip, tail flick, hot plate and writhing tests. Supporting Information available online at http://www.thieme-connect.de/ejournals/toc/amf.

Synthesis of cyclopentapyridine and thienopyridine derivatives as potential calcium channel modulators.

In this study, novel condensed 1,4-dihydropyridines bearing cyclopentanone (1-21) or tetrahydrothiophene-1,1-dioxide ring (22-42) with various ester substituents were synthesized via a modified Hantzsch reaction and their calcium channel modulator activities were investigated on isolated rat ileum and rat thoracic aorta. The introduction of a cyclopentanone ring fused to the 1,4-dihydropyridine nucleus and methyl, ethyl and allyl moieties to the ester group led to more active calcium modulators.

Chroman and tetrahydroquinoline ureas as potent TRPV1 antagonists.

Novel chroman and tetrahydroquinoline ureas were synthesized and evaluated for their activity as TRPV1 antagonists. It was found that aryl substituents on the 7- or 8-position of both bicyclic scaffolds imparted the best in vitro potency at TRPV1. The most potent chroman ureas were assessed in chronic and acute pain models, and compounds with the ability to cross the blood-brain barrier were shown to be highly efficacious. The tetrahydroquinoline ureas were found to be potent CYP3A4 inhibitors, but replacement of bulky substituents at the nitrogen atom of the tetrahydroisoquinoline moiety with small groups such as methyl can minimize the inhibition.

(R)-(5-tert-butyl-2,3-dihydro-1H-inden-1-yl)-3-(1H-indazol-4-yl)-urea (ABT-102) blocks polymodal activation of transient receptor potential vanilloid 1 receptors in vitro and heat-evoked firing of spinal dorsal horn neurons in vivo.

The transient receptor potential vanilloid (TRPV) 1 receptor, a nonselective cation channel expressed on peripheral sensory neurons and in the central nervous system, plays a key role in pain. TRPV1 receptor antagonism is a promising approach for pain management. In this report, we describe the pharmacological and functional characteristics of a structurally novel TRPV1 antagonist, (R)-(5-tert-butyl-2,3-dihydro-1H-inden-1-yl)-3-(1H-indazol-4-yl)-urea (ABT-102), which has entered clinical trials. At the recombinant human TRPV1 receptor ABT-102 potently (IC(50) = 5-7 nM) inhibits agonist (capsaicin, N-arachidonyl dopamine, anandamide, and proton)-evoked increases in intracellular Ca(2+) levels. ABT-102 also potently (IC(50) = 1-16 nM) inhibits capsaicin-evoked currents in rat dorsal root ganglion (DRG) neurons and currents evoked through activation of recombinant rat TRPV1 currents by capsaicin, protons, or heat. ABT-102 is a competitive antagonist (pA(2) = 8.344) of capsaicin-evoked increased intracellular Ca(2+) and shows high selectivity for blocking TRPV1 receptors over other TRP receptors and a range of other receptors, ion channels, and transporters. In functional studies, ABT-102 blocks capsaicin-evoked calcitonin gene-related peptide release from rat DRG neurons. Intraplantar administration of ABT-102 blocks heat-evoked firing of wide dynamic range and nociceptive-specific neurons in the spinal cord dorsal horn of the rat. This effect is enhanced in a rat model of inflammatory pain induced by administration of complete Freund's adjuvant. Therefore, ABT-102 potently blocks multiple modes of TRPV1 receptor activation and effectively attenuates downstream consequences of receptor activity. ABT-102 is a novel and selective TRPV1 antagonist with pharmacological and functional properties that support its advancement into clinical studies.

Identification of (R)-1-(5-tert-butyl-2,3-dihydro-1H-inden-1-yl)-3-(1H-indazol-4-yl)urea (ABT-102) as a potent TRPV1 antagonist for pain management.

Vanilloid receptor TRPV1 is a cation channel that can be activated by a wide range of noxious stimuli, including capsaicin, acid, and heat. Blockade of TRPV1 activation by selective antagonists is under investigation by several pharmaceutical companies in an effort to identify novel agents for pain management. Here we report that replacement of substituted benzyl groups by an indan rigid moiety in a previously described N-indazole- N'-benzyl urea series led to a number of TRPV1 antagonists with significantly increased in vitro potency and enhanced drug-like properties. Extensive evaluation of pharmacological, pharmacokinetic, and toxicological properties of synthesized analogs resulted in identification of ( R)-7 ( ABT-102). Both the analgesic activity and drug-like properties of ( R)-7 support its advancement into clinical pain trials.

In vitro structure-activity relationship and in vivo characterization of 1-(aryl)-3-(4-(amino)benzyl)urea transient receptor potential vanilloid 1 antagonists.

The synthesis and structure-activity relationship of 1-(aryl)-3-(4-(amino)benzyl)urea transient receptor potential vanilloid 1 (TRPV1) antagonists are described. A variety of cyclic amine substituents are well tolerated at the 4-position of the benzyl group on compounds containing either an isoquinoline or indazole heterocyclic core. These compounds are potent antagonists of capsaicin activation of the TRPV1 receptor in vitro. Analogues, such as compound 45, have been identified that have good in vivo activity in animal models of pain. Further optimization of 45 resulted in compound 58 with substantially improved microsome stability and oral bioavailability, as well as in vivo activity.

Alpha-methylation at benzylic fragment of N-aryl-N'-benzyl ureas provides TRPV1 antagonists with better pharmacokinetic properties and higher efficacy in inflammatory pain model.

SAR studies for N-aryl-N'-benzyl urea class of TRPV1 antagonists have been extended to cover alpha-benzyl alkylation. Alkylated compounds showed weaker in vitro potencies in blocking capsaicin activation of TRPV1 receptor, but possessed improved pharmacokinetic properties. Further structural manipulations that included replacement of isoquinoline core with indazole and isolation of single enantiomer led to TRPV1 antagonists like (R)-16a with superior pharmacokinetic properties and greater potency in animal model of inflammatory pain.

The effects of some nonsteroidal anti-inflammatory drugs on experimental induced gastric ulcers in rats.

Celecoxib is a frequently used nonsteroidal anti-inflammatory drug (NSAID) in the treatment of rheumatoid arthritis and osteoarthritis. It selectively inhibits cyclooxygenase II (COX-2) enzyme which is responsible for the production of proinflammatory prostanoids. It has been proposed that since it does not significantly inhibit COX-1, an isoenzyme responsible for the production of cytoprotective prostanoids, celecoxib has fewer side effects in the stomach. Dipyrone which is a drug with potent analgesic activity has no significant inhibitory effect on COX. In this study, the effects of celecoxib and dipyrone on experimentally induced gastric ulcers in rats were compared with respect to different parameters. In the first experiment, in an attempt to identify the best dose for both drugs, a histamine-induced gastric ulcer model was used and each drug was administered at 5, 25 and 100 mg/kg doses, and ulcer index, acidity and mucus secretion were measured in the stomach. The best dose was determined to be 5 mg/kg for both drugs. Celecoxib was found to delay ulcer healing when compared to dipyrone especially when ulcer index was used as measure. In the second experiment, ulcer index, acidity, mucus secretion, and the levels of myeloperoxidase (MPO), lipid peroxide (MDA), non-protein sulfhydryl groups (NP-SH), and prostaglandin E2 (PGE2) were investigated in the stomach of rats with gastric ulcers induced by histamine, stress and diethyldithiocarbamate (DDC). While celecoxib increased the ulcer index in stress-induced ulcer, dipyrone decreased the index in DDC-induced ulcer. Celecoxib also caused a significant increase of gastric mucus secretion in histamine-induced ulcer model. Gastric lipid peroxidation was significantly increased by dipyrone in the control group without gastric ulcer induction, whereas it was significantly increased by celecoxib in the histamine-induced and stress-induced ulcer groups. Dipyrone promoted a decrease in gastric NP-SH levels in the control group with stress-induced ulcer. With respect to gastric MPO activity, dipyrone caused a decrease in the histamine-induced ulcer group but it caused an increase in the stress-induced and DDC-induced ulcer groups. Gastric PGE2 levels in the control group without gastric ulcer induction were not affected by celecoxib while they were increased by dipyrone. In conclusion, celecoxib prompted the formation of experimentally induced gastric ulcers more than did dipyrone. The study was supported by Osmangazi University Research Funds.

Calcium channel blockers increase the amount of nitrite production in rabbits without decreasing the responsiveness of platelets to collagen.

By virtue of their ability to increase nitric oxide (NO) production, it is thought that calcium channel blockers (CCBs) may be involved in the inhibition of platelet aggregation. In an attempt to compare the abilities of different groups of calcium antagonists to affect NO generation and platelet aggregation, single doses of the calcium antagonists verapamil, nicardipine and diltiazem were administered to rabbits. It was found that each of these drugs increased the levels of nitrite significantly. It was also found that these drugs had different time courses of action. Of the CCBs used in this study, verapamil was found to induce the greatest increase in nitrite production (about a 4-fold increase over basal levels), peaking at 90 min (P<0.001). Diltiazem and nicardipine (3.5-fold and 2.5-fold increase over basal levels, respectively) were both found to induce increases in NO which peaked at 150 min (P<0.001 and P<0.01 respectively). Each of the drugs was then given at double the original dose; however, nicardipine was the only drug that was seen to further increase nitrite production (P<0.001). Blood samples taken from the animals were analysed using whole-blood aggregometry in order to assess the amount of collagen-induced platelet aggregation. At the time point when NO release was expected to be maximal (150 min), it was found that the collagen-induced platelet responses were not significantly altered in platelets from rabbits that had been treated with either verapamil or nicardipine. In contrast, at the 150-min time point, diltiazem treatment made the platelets hypersensitive to collagen stimulation. The results of this study demonstrate that treatment with calcium channel antagonists increases the levels of NO produced in rabbits, however, this increase in NO production is not accompanied by a decrease in the reactivity of platelets to collagen.

Studies on condensed 1,4-dihydropyridine derivatives and their calcium modulatory activities.

Hexahydroquinoline and furoquinoline derivatives were synthesized and their calcium modulatory activity was investigated on isolated rat ileum and lamb carotid artery. In addition, the in vitro hepatic microsomal biotransformation of one hexahydroquinoline derivative was studied in rat microsomes.

Structure-activity studies of a novel series of 5,6-fused heteroaromatic ureas as TRPV1 antagonists.

Novel 5,6-fused heteroaromatic ureas were synthesized and evaluated for their activity as TRPV1 antagonists. It was found that 4-aminoindoles and indazoles are the preferential cores for the attachment of ureas. Bulky electron-withdrawing groups in the para-position of the aromatic ring of the urea substituents imparted the best in vitro potency at TRPV1. The most potent derivatives were assessed in in vivo inflammatory and neuropathic pain models. Compound 46, containing the indazole core and a 3,4-dichlorophenyl group appended to it via a urea linker, demonstrated in vivo analgesic activity upon oral administration. This derivative also showed selectivity versus other receptors in the CEREP screen and exhibited acceptable cardiovascular safety at levels exceeding the therapeutic dose.

5-Hydroxytryptamine-2A receptor gene (HTR 2 A) candidate polymorphism (T 102 C): Role for human platelet function under pharmacological challenge ex vivo.

Although the environmental and life-style factors influencing individual predisposition to acute myocardial infarction (AMI) have been well documented, little is known on the identity of genetic loci that may contribute to risk for AMI. Recently, genetic studies in patients with nonfatal AMI have suggested an association with the T 102 C polymorphism in the serotonin 5-HT(2A) receptor gene (HTR 2 A). Considering the significant role of the 5-HT(2A) receptor in serotonin-induced platelet responses and the contribution of platelet (patho)physiology to thromboembolic events, we postulated that the increased susceptibility to AMI in patients with the T 102 homozygosity may be attributable, in part, to altered serotonin-mediated platelet function. In a group of healthy volunteers recruited from the Eskisehir region in central Turkey (N=37), we investigated the functional consequences of HTR 2 A T 102 C polymorphism in relation to platelet pharmacodynamics ex vivo. The platelet shape change and aggregation response to serotonin were measured with use of the platelet aggregometry and expressed as aggregometer output (mm). Because the circulating catecholamine hormone epinephrine can augment platelet aggregation, pharmacodynamic response (aggregation and its inhibition by 5-HT(2A) receptor antagonist cyproheptadine) was measured in the presence of both serotonin and epinephrine, to mimic the clinical situation in patients. The mean platelet aggregation was higher by 38% in subjects with T 10 2 homozygosity (T/T genotype, N=13) when compared with the carriers of the 102 C-allele (T/C and the C/C genotypic groups, N=24) (39.5 mm+/-12.3 vs. 28.7 mm+/-16.8, respectively) (mean+/-SD) (p<0.05). On the other hand, neither the serotonin-induced platelet shape change nor the cyproheptadine inhibition of platelet aggregation was influenced by the HTR 2 A T 102 C genetic variation (p>0.05). These findings in healthy subjects may provide a mechanistic explanation for the previously reported genetic association between HTR 2 A and AMI. Further genetic association studies of the 5-HT(2A) receptor in patients with AMI in different populations are warranted.