Characterization of the anticonvulsant activity of doxepin in various experimental seizure models in mice

In this paper, the anticonvulsant characteristics of doxepin were evaluated in numerous experimental seizure models, including maximal electroshock (MES)-, pentylenetetrazole (PTZ)-, isoniazid (ISO)-, 3-mercaptopropionic acid (3-MP)-, bicuculline (BIC)-, thiosemicarbazide (THIO)-, and strychnine (STR)-induced seizures. In addition, the acute adverse-effect profile of doxepin with respect to impairment of motor coordination was assessed with a mouse rotarod test. The evaluation of the time-course and doseresponse relationships for doxepin provided evidence that the peak maximum anticonvulsant activity and acute adverse effects occurred 5 min after intraperitoneal (ip) administration. The results also revealed that doxepin had excellent anticonvulsant activity against maximal electroshock-induced seizures in mice with a median effect value (ED₅₀) of 6.6 mg/kg. The assessment of acute adverse effects in the rotarod test revealed that doxepin induced acute neurotoxicity, and its median toxic dose (TD₅₀) was 26.4 mg/kg. Additionally, doxepin showed anticonvulsant activity in several chemically-induced seizure models, including ISO, 3-MP, BIC, and THI. Based on this study, we can conclude that the antidepressant drug doxepin may be useful for treatment of depression in patients with epilepsy due to its short time to peak maximum anticonvulsant activity after ip administration (5 min) and remarkable anticonvulsant activity (6.6 mg/kg).     

Synthesis and Biological Evaluation of [1,2,4]Triazolo[3,4‐a]phthalazine and Tetrazolo[5,1‐a]phthalazine Derivatives Bearing Substituted Benzylpiperazine Moieties as Positive Inotropic Agents

Two series of [1,2,4]triazolo[3,4‐a]phthalazine and tetrazolo[5,1‐a]phthalazine derivatives bearing substituted benzylpiperazine moieties have been synthesized and evaluated for their positive inotropic activity by measuring left atrium stroke volume on isolated rabbit heart preparations. The majority of the derivatives exhibited better in vitro activity than the existing drug, milrinone, and 6‐((4‐(4‐methoxyphenyl)piperazin‐1‐yl)methyl)tetrazolo[5,1‐a]phthalazine. 8 m in particular was identified as the most potent with an increased stroke volume of 12.02 ± 0.20% (milrinone: 2.46 ± 0.07%) at a concentration of 3 × 10^–5 m . The chronotropic effects of the compounds that exhibited good potency were also evaluated.     

Anti-inflammatory and antinociceptive effects of 6-(4-chlorophenoxy)-tetrazolo[5,1-a]phthalazine in mice

BackgroundQUAN-0808 (6-(4-chlorophenoxy)-tetrazolo[5,1-a]phthalazine), a new phthalazine tetrazole derivative, was evaluated for the anti-inflammatory and analgesic effects.MethodsXylene-induced ear edema, carrageenan (Carr)-induced paw edema, and acetic acid-induced capillary permeability hyperactivity in mice were used to assess the anti-inflammatory effect; acetic acid-induced writhing and hot plate responses for the analgesic activity.ResultsIn the present study, QUAN-0808 (100, 200, 400 mg/kg) and indomethacin (Indo) significantly decreased xylene-induced ear edema by 33.3, 37.5, 46.6, and 45.1%, respectively, decreased Carr-induced paw edema at 1, 2, 4 h after Carr injection, and decreased the prostaglandin E2 (PGE2) and nitric oxide (NO) levels on the edema paw at 4 h after Carr injection; QUAN-0808 (100, 200, 400 mg/kg), and aspirin (Asp, 200 mg/kg) significantly decreased Evans blue exudation in acetic acid-induced capillary permeability hyperactivity model by 26.7, 28.7, 32.3 and 29.1%, respectively, and decreased the numbers of acetic acid-induced writhing response in 15 min by 40.4, 53.6, 66.4, and 64.5%, respectively. Morphine (10 mg/kg) significantly increased the latency of the hot plate response by 136.5,117.4,67.5, and 22.7%, respectively, at 30, 60, 90, 120 min after intraperitoneal injection of morphine; however, QUAN-0808 (100, 200 and 400 mg/kg) did not produce significantly antinociceptive effects in the hot plate test, suggesting that its antinociceptive action occurs via peripheral rather than a central-acting mechanism.ConclusionsThese results show that QUAN-0808 produced potential anti-inflammatory and peripheral antinociceptive effects, and indicated that the antinociceptive effects of QUAN-0808 were related to its anti-inflammatory activity in a dose-dependent manner. Therefore, as inflammation is a peripheral process, it is suggested that QUAN-0808 exerted peripheral effects. The peripheral effect mechanisms of QUAN-0808 may be related to a decrease in the production of PGE₂, NO, bradykinin and other inflammatory mediators.     

Influence of etoricoxib on anticonvulsant activity of phenytoin and diazepam in experimental seizure models in mice

Objectives Our aim was to investigate the effect of etoricoxib on the anticonvulsant activity of phenytoin and diazepam against seizure models in mice. In addition the acute adverse effect of etoricoxib was assessed with a chimney test. Methods The maximal seizure pattern was induced in mice by giving an alternating current of 50 mA for 0.2 s, while chemical seizures were induced by intraperitoneal injection of pentylenetetrazole at its CD97 dose (97% convulsive dose for the clonic phase). Test drug was administered 45 min before the electrical or chemical induction of seizures in combination with conventional antiepileptics. The ability of the test drug to reduce or abolish the extensor phase of maximal electroshock and clonic‐type seizures in the chemical induction method was selected as anti‐seizure criteria. Key findings Concurrent treatment with etoricoxib at an oral dose of 10 mg/kg reduced the anticonvulsant potency of phenytoin. The protective effects of diazepam against pentylenetetrazole‐induced convulsions was significantly increased and the mortality rate was reduced by concurrent treatment with etoricoxib (10 mg/kg p.o.) when compared with diazepam groups. No neurotoxic effect was observed with etoricoxib (10 mg/kg p.o.) and it had no impact on motor coordination in the chimney test in mice. Etoricoxib applied at its highest dose (10 mg/kg) significantly enhanced the free plasma levels of diazepam whereas the free plasma levels of phenytoin were significantly reduced. Conclusions The obtained results suggest that the preferential cyclooxygenase‐2 inhibitor etoricoxib significantly reduced the anticonvulsant action of phenytoin and significantly increased the beneficial action of diazepam against maximal electroshock and pentylenetetrazole‐induced convulsions in a mouse model.     

Quinoxaline chemistry. Part 16. 4-substituted anilino and 4-substituted phenoxymethyl pyrrolo[1,2-a]quinoxalines and N-[4-(pyrrolo[1,2-a]quinoxalin-4-yl)amino and hydroxymethyl]benzoyl glutamates. Synthesis and evaluation of in vitro biological activity

Twenty eight pyrrolo[1,2-a]quinoxalines bearing at position 4 various substituents related to the moieties present in classical and non classical antifolic agents were prepared and evaluated in vitro for antiproliferative activity. In an in vitro screening performed at NCI, several compounds emerged as potent antiproliferative agents at concentrations ranging between 10 and 100 microM. Interestingly, some of these compounds proved active also against bovine and murine DHFR (Farmaco 53 (1998) 480). More recently, a compound of classical antifolate type has been reported to be a potent inhibitor of hDHFR in vitro (Farmaco 58 (2003) 51). We then synthesized new derivatives that, in our hands, were endowed with in vitro antiproliferative activities as low as 3.4 microM against a panel of cell lines derived from hematological and solid tumours. In addition, a complete screening of cytotoxicity, antiretroviral HIV-1 and antimicrobial activity has been carried out.     

2-(咪唑并[1, 2-a]吡啶-3-基)乙酸的合成工艺改进

目的 改进抗骨质疏松药米诺膦酸的关键中间体2-(咪唑并[1, 2-a]吡啶-3-基)乙酸的制备方法。方法 以2-氧代戊二酸二乙酯为起始原料,经溴代、环合、水解和脱羧4步反应制得目标产物。结果 目标化合物的熔点与¹H-NMR 谱数据与文献报道相符,总收率为40.5%(以2-氧代戊二酸二乙酯计)。结论 与文献报道的方法相比,改进后的工艺路线后处理简单,更有利于工业化生产。     

Radiosynthesis of 2-[6-chloro-2-(4-iodophenyl)imidazo[1,2-a]pyridin-3-yl]-N-ethyl-N-[11C]methyl-acetamide, [11C]CLINME,a novel radioligand for imaging the peripheral benzodiazepine receptors with PET

Recently, a new 2-(iodophenyl)imidazo[1,2-a]pyridineacetamide series has been developed as iodine-123-labelled radioligands for imaging the peripheral benzodiazepine receptors using single photon emission tomography. Within this series, 2-[6-chloro-2-(4-iodophenyl)-imidazo[1,2-a]pyridin-3-yl]-N-ethyl-N-methyl-acetamide (CLINME) was considered as an appropriate candidate for positron emission tomography imaging and was isotopically labelled with carbon-11 (T_1/2: 20.38 min) at the methylacetamide side chain from the corresponding nor-analogue using [¹¹C]methyl iodide and the following experimental conditions: (1) trapping at −10°C of [¹¹C]methyl iodide in a 1/2 (v:v) mixture of DMSO/DMF (300 µl) containing 0.7–1.0 mg of the precursor for labelling and 3–5 mg of powdered potassium hydroxide (excess); (2) heating the reaction mixture at 110°C for 3 min under a nitrogen stream; (3) diluting the residue with 0.6 ml of the HPLC mobile phase; and (4) purification using semi-preparative HPLC (Zorbax^® SB18, Hewlett Packard, 250 × 9.4 mm). Typically, starting from a 1.5 Ci (55.5 GBq) [¹¹C]CO₂ production batch, 120−150 mCi (4.44–5.55 GBq) of [¹¹C]CLINME were obtained (16–23% decay-corrected radiochemical yield, n=12) within a total synthesis time of 24–27 min (Sep-pak^®Plus-based formulation included). Specific radioactivities ranged from 0.9 to 2.7 Ci/µmol (33.3–99.9 GBq/µmol) at the end of radiosynthesis. Copyright © 2007 John Wiley & Sons, Ltd.     

Screening of the anticonvulsant activity of some plants from Fabaceae family in experimental seizure models in mice

BACKGROUND AND PURPOSE OF THE STUDY: Fabaceae is the third largest family of flowering plants. Lack of essential oils in the plants of this family can be an advantage in search for safe and effective medicines. In this study the anticonvulsant effect of the leaves of Albizzia julibrissin, Acacia juliflora, Acacia nubica and aerial parts of Astragalus obtusifolius was evaluated in pentylenetetrazole (PTZ) and maximal electroshock (MES) seizure tests. METHODS: The hydroalcoholic extracts of the plants were obtained by percolation. Different doses of the extracts were injected to the mice intraperitoneally (i.p.) and occurrence of clonic seizures induced by PTZ (60 mg/kg, i.p.) or tonic seizures induced by MES (50 mA, 50Hz, 1sec) were monitored up to 30 min after administration. Acute toxicity of the extracts was also assessed. The safe and effective extract was then fractionated by dichloromethane and anticonvulsant activity of the fractions was determined. Finally, the constituents of the extract and the fractions were screened by thin layer chromatography. RESULTS: Among the extracts, only A. obtusifolius extract showed low toxicity and protective effect against clonic seizures with ED50 value of 3.97 g/kg. Fractionation of the extract led to increase in anticonvulsant activity and ED50 value of 2.86 g/kg was obtained for the aqueous fraction. Phytochemical screening revealed the presence of alkaloids, flavonoids, anthrones and saponins in the aqueous fraction. MAJOR CONCLUSION: The presence of anticonvulsant compounds in A. obtusifolius suggests further activity-guided fractionation and analytical studies to find out the potential of this plant as a source of anticonvulsant agent.     

Synthesis of 2-(4-substitutedbenzyl-[1,4]diazepan-1-yl)-n-(1-methyl-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamides as inotropic agents

In an attempt to search for more potent positive inotropic agents, a series of N-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-yl)-2-(substitutedbenzyl-[1,4]diazepan-1-yl)acetamides were synthesized and evaluated for positive inotropic activity by measuring left atrium stroke volume in isolated rabbit heart preparations. Some of these derivatives exhibited favorable activity compared with the standard drug, milrinone, among which 2-(4-(4-methylbenzyl)-[1,4]-diazepan-1-yl)-N-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-yl)acetamide (6m) was the most potent, increasing stroke volume by 8.38±0.16% (milrinone 2.45± 0.06%) at 3 x 10(-5) m. The chronotropic effects of those compounds having inotropic effects were also evaluated in this work.     

Synthesis of (+)-(3R)-3-(4-fluorophenylsulfonamido)-1,2,3,4-tetrahydro-9-[5,6,7,8,12,13-U-14C]carbazolepropanoic acid, [14C]BAY u 3405

The title compound [¹⁴C]BAY u 3405 ( 1 ) was synthesized as part of 8-step sequence. Starting from [U-¹⁴C]aniline hydrogensulfate the final product 1 was obtained with a specific activity of 741 MBq/mmol (20 mCi/mmol) and a radiochemical purity of > 98% in an overall yield of 6 and 10% depending on the method.     

4-Chlorotetrazolo[1,5-a]quinoxaline inhibits activation of Syk kinase to suppress mast cells in vitro and mast cell-mediated passive cutaneous anaphylaxis in mice

4-Chlorotetrazolo[1,5-a]quinoxaline is a quinoxaline derivative. We aimed to study the effects of 4-chlorotetrazolo[1,5-a]quinoxaline on activation of mast cells in vitro and in mice. 4-Chlorotetrazolo[1,5-a]quinoxaline reversibly inhibited degranulation of mast cells in a dose-dependent manner, and also suppressed the expression and secretion of TNF-α and IL-4 in mast cells. Mechanistically, 4-chlorotetrazolo[1,5-a]quinoxaline inhibited activating phosphorylation of Syk and LAT, which are crucial for early FcεRI-mediated signaling events, as well as Akt and MAP kinases, which play essential roles in the production of various pro-inflammatory cytokines in mast cells. Notably, although 4-chlorotetrazolo[1,5-a]quinoxaline inhibited the activation of Fyn and Syk, minimal inhibition was observed in mast cells in the case of Lyn. Furthermore, consistent with its in vitro activity, 4-chlorotetrazolo[1,5-a]quinoxaline significantly suppressed mast cell-mediated passive cutaneous anaphylaxis in mice. In summary, the results from this study demonstrate that 4-chlorotetrazolo[1,5-a]quinoxaline shows an inhibitory effect on mast cells in vitro and in vivo, and that this is mediated by inhibiting the activation of Syk in mast cells. Therefore, 4-chlorotetrazolo[1,5-a]quinoxaline could be useful in the treatment of mast cell-mediated allergic diseases.     

Analgesic, anticonvulsant and antioxidant activities of 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one dihydrochloride in mice

Recently we have shown that 3-[4-(3-trifluoromethyl-phenyl)-piperazin-1-yl]-dihydrofuran-2-one dihydrochloride (LPP1) is an antinociceptive and local anesthetic agent in rodents. Below an extended study of the pharmacological activity of LPP1 is described. In vitro LPP1 has no affinity for GABA_A, opioidergic μ and serotonergic 5-HT_1A receptors. The total antioxidant capacity of LPP1 (1-10 mM) measured as ABTS radical cation-scavenging activity showed that LPP1 has dose-dependent antioxidant properties in vitro. Low plasma concentration of this compound detected by means of HPLC method 30 min after its intraperitoneal administration suggests a rapid conversion to metabolite(s) which may be responsible for its analgesic and anticonvulsant activities in vivo.In vivo the compound's influence on the electroconvulsive threshold and its activity in the maximal electroshock seizure test (MES) were evaluated. The results demonstrated that LPP1 had an anticonvulsant activity in the MES model (ED₅₀ = 112 mg/kg) and at a dose of 50 mg/kg was able to elevate the electroconvulsive threshold for 8 mA as compared to the vehicle-treated mice. The analgesic activity of LPP1 was investigated in the acetic acid-induced writhing test in two groups of mice: animals with sensory C-fibers ablated, and mice with C-fibers unimpaired. It proved the potent activity of this compound in both groups (approximately 85% as compared to the vehicle-treated mice). The adverse effects of LPP1 were evaluated as acute toxicity (LD₅₀ = 747.8 mg/kg) and motor coordination impairments in the rotarod and chimney tests. The results from these tests show that LPP1 at doses higher than 100 mg/kg is likely to impair the motor performance of experimental animals. Concluding, LPP1 is an analgesic and anticonvulsant compound which has antioxidant properties in vitro. Further studies are necessary to assess whether the antioxidant activity and the receptor profiling demonstrated in vitro can be confirmed for its metabolite(s) that are formed in vivo.     

Synthesis of high specific activity (3,4-[3H]cyclohexyl)-N-[1 (2-benzo[b]thienyl)cyclohexyl]piperidine {[3H]BTCP}: A selective probe for the dopamine-reuptake complex

High specific activity [³H]BTCP, a radioligand for the dopaminereuptake complex was synthesized in 7-steps starting with the readily available starting materials, cyclohexane-1,4-dione monoethylene ketal and benzo[b]thiophene; the tritium label was introduced in the final step on the 3- and 4- positions of the cyclohexyl ring by catalytic tritiation of N-[4-(2-benzo[b]thienyl)cyclohexenyl]piperidine to give [³H]BTCP in 7.3% yield with a specific activity of 29.8 Ci/mmol (51.4% isotopic incorporation).     

Investigations on the synthesis and pharmacological properties of 4-alkoxy-2-[2-hydroxy-3-(4-aryl-1-piperazinyl)propyl]-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones

Synthesis of 2-[2-hydroxy-3-(4-aryl-1-piperazinyl)propyl] derivatives of 4-alkoxy-6-methyl-1H-pyrrolo[3,4-c]pyridine-1,3(2H)-diones (8-12) is described. The chlorides used in the above synthesis can exist in two isomeric forms: chain (18-20) and cyclic (19a, 20a). The compounds 8-12 exhibited potent analgesic activity which was superior than that of acetylsalicylic acid in two different tests. Most of the investigated imides suppressed significantly spontaneous locomotor activity in mice.     

4-[4-(吡啶-3-基)咪唑-1-基]丁胺的合成

以3-乙酰基吡啶为起始原料,经肟化、磺酰化、氧化、环合、还原得到3-(咪唑-4-基)吡啶,再经与N-(4-溴丁基)邻苯二甲酰亚胺缩合及肼解等反应制得抗菌剂泰利霉素的特定侧链化合物4-[4-(吡啶-3-基)咪唑-1-基]丁胺,总收率24%.     

呋苄头孢菌素和呋苄青霉素钾的极谱行为研究

本文研究呋苄头孢菌素和呋苄青霉素钾的极谱行为。两样品在-1.1 V附近有一清晰的单扫描极谱波,在一定的浓度范围内蜂电流与样品浓度之间呈良好的线性关系,可用作定量分析。本文还对电极反应机理进行了初步的探讨,并证明此波具有吸附性质。     

咪苯嗪酮对花生四烯酸诱导的大鼠脑血栓形成的影响

花生四烯酸(AA)0.25～1 mg·kg~(-1)经颈内动脉注射能诱发大鼠同侧大脑半球脑内血栓形成,明显增加伊文思蓝通过血脑屏障渗入脑实质的量,峰值为205±s 50 mg·kg~1脑组织,相应对照组为10±s 5mg·kg~1,咪苯嗪酮0.25～0.5mg·kg~1 iv能对抗AA引起的大鼠脑血栓形成,显著降低脑实质内伊文思蓝的含量,作用呈剂量依赖性,且强于哒唑氧苯     

3-[3-(Phenalkylamino)cyclohexyl]phenols: Synthesis,biological activity,and in silico investigation of a naltrexone-derived novel class of MOR-antagonists

The development of novel μ-opioid receptor (MOR) antagonists is one of the main objectives of drug discovery and development. Based on a simplified version of the morphinan scaffold, 3-[3-(phenalkylamino)cyclohexyl]phenol analogs were designed, synthesized, and evaluated for their MOR antagonist activity in vitro and in silico. At the highest concentrations, the compounds decreased by 52% to 75% DAMGO-induced GTPγS stimulation, suggesting that they acted as antagonists. Moreover, Extra-Precision Glide and Generalized-Born Surface Area experiments provided useful information on the nature of the ligand–receptor interactions, indicating a peculiar combination of C-1 stereochemistry and N-substitutions as feasibly essential for MOR–ligand complex stability. Interestingly, compound 9 showed the best experimental binding affinity, the highest antagonist activity, and the finest MOR–ligand complex stability. In silico experiments also revealed that the most promising stereoisomer (1R, 3R, 5S) 9 retained 1,3-cis configuration with phenol ring equatorial oriented. Further studies are needed to better characterize the pharmacodynamics and pharmacokinetic properties of these compounds.     

3,4-二氢吡咯[1,2-a]吡嗪-1-酮衍生物的合成及抗炎镇痛作用

目的研究(2H)-2-环己基-3,4-二氢吡咯[1,2-a]吡嗪-1-酮衍生物抗炎镇痛作用的构效关系。方法以2-吡咯甲酸甲酯为原料,经取代、环合,制备(2H)-2-环己基-3,4-二氢吡咯[1,2-a]吡嗪-1-酮(3);通过Friedel-Crafts酰基化反应,制得其6-酰基衍生物4a~4j。用小鼠测试了所合成化合物的抗炎和镇痛活性。结果与结论合成了10个未见文献报道的新化合物4a~4j,其结构经MS1、H-NMR分析确证。抗炎镇痛试验表明,有些化合物具有明显的抗炎和/或镇痛作用,其中化合物4d的活性与对照药布洛芬相当。     

对氯苯氧异丁酸甲氧基苯丙烯酸酯对人肝癌细胞HepG2脂肪累积的干预作用

目的:研究对氯苯氧异丁酸甲氧基苯丙烯酸酯(AZ)对人肝癌细胞Hep G2脂肪累积的干预作用。方法:取对数生长期Hep G2细胞,用油酸诱导复制脂肪累积模型,分为模型组、阳性对照(辛伐他汀100μg/ml)组和15.63、31.25、62.5、125、250、500、1 000μg/ml AZ组,另设正常对照组。采用MTT法检测各组细胞的存活率;按试剂盒操作检测各组细胞中甘油三酯(TG)含量,计算TG清除率;油红O染色观察各组细胞内脂滴形态。结果:与正常对照组比较,模型组和15.63~125μg/ml AZ组细胞的存活率差异无明显变化,250~1 000μg/ml AZ组细胞存活率降低,差异具有统计学意义(P<0.05)。与正常对照组比较,模型组细胞中TG含量增加;与模型组比较,阳性对照组和62.5、125μg/ml AZ组细胞中TG含量降低,TG清除率依次为(28.58±0.15)%、(14.51±0.09)%、(29.72±0.16)%,以上差异均具有统计学意义(P<0.01或P<0.05)。与正常对照组比较,模型组细胞出现大量脂滴,AZ组随给药浓度的增加,脂滴逐渐变少、变小。结论:AZ对Hep G2细胞脂肪累积具有干预作用。