4种ω-芋螺毒素的合成及活性研究

目的 合成新型ω-芋螺毒素,测定其作用靶标,获得新型镇痛分子并为N-型钙离子通道抑制剂设计提供依据。方法 采用固相法合成线性肽,然后进行折叠、富集和纯化得到纯肽;利用膜片钳技术,测定其对N、P/Q及L-型钙离子通道的抑制活性;利用金鱼测定毒副作用,采用热板法和醋酸扭体法测定活性高毒素的镇痛活性。结果 Ac6.4对N-型钙离子通道抑制活性高,IC50为0.42 μmol/L;C6.4、Castu-c2及Di7.5的抑制活性较低,10 μmol/L的C6.4、Castu-c2及Di7.5的抑制活性分别为（35.58 ± 12.32）%、（31.09 ± 12.24）%及（14.03 ± 4.84）%。该4种ω-芋螺毒素对P/Q、L-型钙离子通道的抑制活性低。1.0~3.0 μg/kg的Ac6.4显著增加小鼠对热板法的痛阈时间,1.0~10.0 μg/kg的Ac6.4显著减少小鼠对醋酸扭体次数,但其镇痛活性均低于齐考诺肽（MVIIA）。Ac6.4的金鱼的毒性显著低于ω-芋螺毒素MVIIA。结论 Ac6.4选择性抑制CaV2.2,且具有较高的镇痛活性及较低毒副作用。     

瓜子金发酵总皂苷的抗炎镇痛活性

目的:研究瓜子金发酵液中所含总皂苷的抗炎镇痛活性。方法:提取瓜子金发酵液中的总皂苷,采用二甲苯诱导小鼠耳廓肿胀试验模型和腹腔毛细血管通透性试验观察抗炎作用;采用小鼠扭体和热板试验观察镇痛作用;采用最大耐受剂量法进行急性毒性试验,观察小鼠出现的毒性反应和剂量毒性效应的关系。结果:瓜子金发酵总皂苷对二甲苯致小鼠耳廓肿胀、冰醋酸致腹腔毛细血管通透性增高均有明显的抑制作用;能减少冰醋酸刺激致痛小鼠的扭体次数及提高热板致痛小鼠的痛阈值;小鼠灌胃最大耐受剂量13.3g.kg-1,相当于临床用量的100倍。结论:瓜子金发酵总皂苷具有显著的抗炎、镇痛作用,且毒性较低。     

野菊花水相萃取物对小鼠镇痛作用研究

目的:研究野菊花水相萃取物(AF)的镇痛作用.方法:应用冰醋酸制备小鼠疼痛模型,以15 min内发生扭体次数为疼痛定量指标;将小鼠置于(55 ±0.5)℃热板上制备小鼠疼痛模型,以小鼠舔后足反应潜伏期为痛阈指标;采用小鼠福尔马林炎性组织疼痛法模型,以小鼠舔足时间为指标,观察其第Ⅰ时相和第Ⅱ时相疼痛反应.结果:野菊花水相萃取物能显著抑制醋酸致小鼠扭体反应;可明显延长热板引起小鼠疼痛反应的痛阈值;对福尔马林致痛模型动物I相和Ⅱ相疼痛反应均有抑制作用.结论:野菊花水相萃取物有明显的镇痛作用.     

胍丁胺代谢产物腐胺对吗啡镇痛、耐受和依赖的影响

目的观察腐胺对吗啡镇痛、耐受及依赖的影响,探讨腐胺治疗阿片耐受性和依赖性的潜力。方法小鼠醋酸扭体模型和55℃热板法测痛阈;吗啡恒定剂量给药制备耐受模型,55℃热板法测痛阈;吗啡递增剂量给药制备依赖模型,纳洛酮催促观察戒断症状,以胍丁胺(40 mg.kg-1,ig)为阳性对照药,腐胺灌胃给药剂量分别为10,20,40,80 mg.kg-1。结果在小鼠醋酸扭体模型中腐胺具有镇痛作用;而在小鼠55℃热板实验中,腐胺本身无镇痛作用,能较弱地增强吗啡镇痛;腐胺能够减弱吗啡耐受的形成,对已形成的吗啡耐受也有治疗作用;腐胺能够减弱吗啡躯体依赖的形成和表达。结论腐胺和胍丁胺具有相似的生物学活性,具有治疗阿片耐受和依赖的潜力。     

槲皮素对急性痛风性关节炎的抗炎、镇痛实验研究

目的探讨黄酮类化合物槲皮素对尿酸钠致急性痛风性关节炎模型大鼠踝关节肿胀度的影响,观察对小鼠的抗炎、镇痛作用。方法采用大鼠右后肢踝关节腔内注射尿酸钠溶液制备急性痛风性关节炎模型,缚线法测定大鼠不同时相踝关节肿胀度。采用耳廓肿胀法、热板法、扭体法观察槲皮素的抗炎、镇痛作用。结果槲皮素能够显著抑制痛风性关节炎大鼠踝关节肿胀度,抑制二甲苯致小鼠耳廓肿胀,提高热板法致痛小鼠痛阈时间,减少醋酸所致小鼠扭体反应次数。结论槲皮素通过抗炎、镇痛作用表现出很强的治疗痛风性关节炎功效,可能成为治疗该病的有效药物。     

蓖麻壳水提液的镇痛作用及其成分分析

目的:研究蓖麻壳水提液的镇痛作用和主要成分的 HPLC 及质谱联用技术分析。方法:以啮齿动物的疼痛模型热板试验和乙酸扭体试验对蓖麻壳的水提液的镇痛进行了评价并利用高效液相色谱/质谱联用技术对浸提液的主要成分进行了分析。结果:小鼠 IP 蓖麻壳水提液组比对照组的扭体次数显著性减少和热板耐受时间显著性增加并有镇痛抑制率和耐受力随剂量增加而显著性提高(P<0.001)。利用 HPLC 和 HPLC/MS 联用技术分析蓖麻壳水提液其主要成分为蓖麻碱。结论:蓖麻壳水提液的活性成分可以明显抑制化学性刺激和热刺激所致的小鼠痛反应,有可能是多模式镇痛,减弱中枢神经系统接收到的疼痛信号和抑制外周疼痛信号。     

玄参总色素提取物抗炎镇痛活性的研究

目的：研究人工栽培玄参中色素提取物的抗炎镇痛作用。方法：采用热板法、冰醋酸刺激致痛法测定小鼠痛阈；利用二甲苯造小鼠耳廓炎症模型，测定小鼠耳片质量；采用腹腔染料渗出法，测定小鼠腹腔毛细血管通透性。结果：玄参色素提取物能提高热板致病小鼠的痛阁值及减少冰醋酸刺激致痛小鼠的扭体次数；对二甲苯致小鼠耳廓肿胀、冰醋酸致腹腔毛细血管通透性增高均有明显的抑制作用。结论：玄参色素提取物有抗炎镇痛的活性。     

N-吲哚烷基哌啶类化合物及其类似物的合成和活性研究

摘 要：目的 以5-羟色胺转运体和5-HT2A受体为靶点,设计合成N-吲哚烷基哌啶类化合物及其类似物,研究它们的体内外生物活性。方法 以苯并五元氮杂化合物为原料,经烷基化反应,再与相应的哌啶或哌嗪类化合物进行缩合制备系列化合物。经5-羟色胺再摄取抑制实验和5-HT_2A受体结合实验进行体外筛选,采用小鼠醋酸扭体法和小鼠热板法对其中优选化合物10c、10e进行体内镇痛活性实验;通过阿片受体结合试验和小鼠急性毒性试验,考察目标化合物作为新型非阿片类镇痛剂的潜在开发价值。 结果与结论 共合成了18个未见文献报道的新化合物, 经高分辨质谱及核磁共振氢谱确证结构。体内外药理研究表明：化合物10c和10e具有较强的5-羟色胺再摄取抑制作用,且与5-HT_2A受体有较高亲和力;10c、10e在两种镇痛模型上均显示出很强的镇痛活性;与阿片μ、δ、κ受体无明显亲和力;毒性较小,具有作为非阿片类新型镇痛剂的开发价值。     

从竹节三七、肉桂、大黄中提纯的天然活性成分的镇痛作用研究

目的 初步研究从竹节三七、肉桂、大黄中提纯的天然活性成分的镇痛作用。方法 通过初试实验找出药物的中剂量档后，利用小鼠热板法和小鼠醋酸扭体法实验，判定药物镇痛作用的强弱。结果 该药物在一定剂量下如(20g／g)能够明显提高小鼠热板的痛阈值，非常明显降低小鼠扭体次数。结论 该药物具有较好镇痛作用，且有一定量效关系。     

荫风轮总苷抗炎镇痛作用研究

目的考察荫风轮总苷的抗炎镇痛作用.方法观察荫风轮总苷(大鼠剂量20、10、5 mg·kg-1;小鼠剂量40、20、10mg·kg-1)对二甲苯致小鼠耳肿胀模型、角叉菜胶致大鼠关节肿胀模型和小鼠血管通透性的作用,应用小鼠热板法和扭体法试验观察药物镇痛作用.结果荫风轮总苷对小鼠毛细血管通透性有显著降低作用,对小鼠二甲苯致耳肿胀模型、大鼠角叉菜胶致关节肿胀模型有作用趋势,而对小鼠热板致痛和醋酸致痛无显著镇痛作用.结论荫风轮总苷具有一定的抗炎作用,但镇痛作用不明显.     

玄芷镇痛片镇痛作用与急性毒理学研究

目的评价玄芷镇痛片的镇痛效果和急性毒性。方法采用小鼠扭体实验和热板实验测定玄芷镇痛片镇痛效果;采用最大耐受量测定法确定玄芷镇痛片口服给药的最大耐受量。结果玄芷镇痛片各剂量组对小鼠醋酸所致的疼痛有显著镇痛作用,并呈量效关系;玄芷镇痛片各剂量组对小鼠物理致痛镇痛效果显著,与阿司匹林组比较,起效时间相同,但作用更持久;玄芷镇痛片口服给药的最大耐受量为259.2 g&#8226;kg－1。结论玄芷镇痛片有较强的镇痛作用,镇痛持续时间长于阿司匹林,且安全。     

马来酸三甲氧苯丁氨酯的镇痛作用

研究马来酸三甲氧苯丁氨酯（ＴＭ）的镇痛作用，结果显示，腹腔注射ＴＭ２４５、３５０、５００ｍｇ／ｋｇ能显著抑制小鼠扭体反应，５０、７０ｍｇ／ｋｇ能显著提高小鼠热板反应痛阈值，３５、５０、７０ｍｇ／ｋｇ则能够显著提高小鼠压尾痛阈值并减少甲醛致痛评分值，３７５、７００ｍｇ／ｋｇ可显著提高大鼠电刺激痛阈值．连续给小鼠腹腔注射ＴＭ７０ｍｇ／ｋｇ７天，每天用热板法测定小鼠痛阈值，表明其镇痛作用无耐受性．     

Opiate and acetylcholine-independent analgesic actions of crotoxin isolated from crotalus durissus terrificus venom.

The venom of Crotalus durissus terrificus is reported to have analgesic activity and the administration of Crotoxin (Cro) to cancer patients is reported to reduce the consumption of analgesics. This study investigated the analgesia induced by Cro and the effects of atropine and naloxone on the antinociceptive activity of Cro in mice and rats. The results showed that Cro at 66.5, 44.3 and 29.5microg/kg (ip) exhibited a dose-dependent analgesic action in mice using the hotplate and acetic acid writhing tests. Cro at 44.3microg/kg (ip) had significant analgesic action in the rat tail-flick test. In the mouse acetic acid-writhing test, intracerebral ventricular administration of Cro 0.3microg/kg produced marked analgesic effects. Microinjection of Cro (0.15microg/kg) into the periaqueductal gray area also elicited a robust analgesic action in rat hotplate test. Atropine at 0.5mg/kg (im) or 10mg/kg (ip) or naloxone at 3mg/kg (ip) failed to block the analgesic effects of Cro. These results suggest that Cro has analgesic effects mediated by an action on the central nervous system. The muscarinic and opioid receptors are not involved in the antinociceptive effects of Cro.     

The antinociceptive properties of reboxetine in acute pain

The antinociceptive effects of the selective noradrenaline reuptake inhibitor antidepressant reboxetine and its interaction with various opioid and noradrenaline receptor subtypes were evaluated. Reboxetine (i.p.) induced a weak dose-dependent antinociceptive effect in acute pain, using the hotplate model. The reboxetine-induced antinociception was significantly inhibited by the opioid receptor antagonists naloxone, nor-BNI, naltrindole and b-FNA, implying a non-selective role for the opioid receptors in the reboxetine's antinociceptive effect. The adrenergic antagonists yohimbine and phentolamine attenuated to some extent the reboxetine-induced antinociception, implying a minor adrenergic mechanism of antinociception. The addition of opioid or α2 agonists, did not potentiate the antinociception effect of reboxetine. Thus, it seems that reboxetine possesses a weak antinociceptive effect, mediated by non-selective opioid receptors and influenced somewhat by noradrenaline α2 receptors. These results suggest that reboxetine as monotherapy does not have sufficient efficacy in the management of acute pain. However, further research is needed in order to establish its possible use alone or in combination with other antidepressants or analgesics in the amelioration of chronic pain disorders.     

Altered pain sensitivity and morphine-induced anti-nociception in mice lacking CCK<Subscript>2</Subscript> receptors

Rationale. Cholecystokinin (CCK) interacts with the endopioid system in the regulation of various physiological functions, including the control of pain sensitivity, motor activity and emotional behaviour. Objective. The aim of the present work was to study the pain sensitivity, morphine-induced antinociception and density of opioid receptors in mice lacking CCK₂ receptors. Methods. Plantar analgesia and hotplate tests were used to evaluate pain sensitivity and morphine-induced antinociception. The parameters of opioid receptors were analysed by using [³H]-diprenorphine binding. Results. In the plantar analgesia test the latency of hind paw withdrawal was significantly increased in CCK₂ receptor deficient mice compared to wild-type (+/+) littermates. The treatment with saline reversed the reduced pain sensitivity in heterozygous (+/−) and homozygous (−/−) mice. The administration of morphine (1 mg/kg) induced a significantly stronger antinociceptive effect in homozygous (−/−) mice compared with wild-type (+/+) animals. In the hotplate test, only homozygous (−/−) mutant mice displayed the delayed latency of hind paw licking/shaking in comparison with wild-type (+/+) mice. The injection of saline and isolation of mice for 30 min reversed the delayed response in homozygous (−/−) mice. However, in this test, the anti-nociceptive action of morphine (5–10 mg/kg) in mutant mice did not differ from that in wild-type (+/+) littermates. By contrast, the jump latency was decreased in both homozygous (−/−) and heterozygous (+/−) mice in the hotplate test. The increased density of opioid receptors was established in the striatum of homozygous (−/−) mice. Conclusion. It is apparent that the targeted mutagenesis of the CCK₂ receptor gene has different effects on the sensitivity of opioid receptors in various brain structures. This is a probable reason for the altered pain sensitivity and morphine-induced antinociception in mutant mice compared to wild-type (+/+) littermates. Electronic Publication     

新型羟基脲化合物Ⅲ_5的镇痛抗炎作用

目的探讨新型羟基脲类化合物Ⅲ5的镇痛及抗炎作用。方法采用小鼠热板法和扭体法证明化合物Ⅲ5的镇痛作用;采用二甲苯致小鼠耳肿胀,醋酸致毛细血管通透性增加,蛋清致大鼠足趾肿胀模型证明化合物Ⅲ5的抗炎作用。结果化合物Ⅲ5能延长小鼠的热痛阈值,能延长造模后小鼠第一次出现扭体反应的潜伏期并减少15 min内扭体反应出现的次数;能显著抑制耳肿胀,醋酸对毛细血管的通透性以及不同时间点大鼠的足趾肿胀度。结论化合物Ⅲ5具有明显的镇痛抗炎作用。     

Studies on new cyclic imides obtained from aminophenazone with analgesic properties. Potent effects of a 3,4-dichloromaleimide derivative

This paper describes the synthesis of new cyclic imides obtained by reaction with aminophenazone (CAS 58-15-1, 4-aminoantipyrine) and different anhydrides with further cyclization with acetic acid under reflux. Their structures were confirmed by spectral data (IR and NMR) and elemental analysis. The analgesic activity of the synthesized compounds was investigated initially with the writhing test in mice and the most promising compound, a 3,4-dichloromaleimide derivative (3), was analyzed using other models of nociception. The results indicated that compound 3 exerts potent analgesic activity in mice, being more active than some reference drugs. The analgesia caused by this compound was not reversed by naloxone in the writhing test. In the hotplate test, compound 3 did not increase the latency period of pain induced by thermal stimuli, confirming that it does not interact with opioid systems.     

The analgesic and toxic effects of nornicotine enantiomers alone and in interaction with morphine in rodent models of acute and persistent pain

Neuronal nicotinic acetylcholinic receptors (nAChR) are promising targets for the development of novel analgesics. Nicotine and other nAChR-agonists produce profound analgesia in rodent models of acute and persistent pain. However, significant side-effects are of concern. Nornicotine (N-desmethyl-nicotine) appears to activate different nAChR subtypes, has a better pharmacokinetic profile, and produces less toxicity than nicotine. Little is known about its analgesic properties. In the present study, the S(−)- and R(+)-enantiomers of nornicotine were characterized with regard to analgesia and side-effects profile. Efficacy was demonstrated in rat models of pain where central sensitization is involved: i.e. the chronic constriction nerve injury model of peripheral neuropathy and the formalin model of tonic inflammatory pain. The desirable (analgesic) properties resided predominantly in the S(−)- rather than the R(+)-enantiomer. In contrast, undesirable effects (motor in-coordination, reduced locomotor activity, ataxia) were more pronounced with the R(+)-enantiomer. This is an interesting finding, which may suggest separation of toxicity from analgesia by utilization of S(−)-enantiomer of nornicotine. Maximum analgesic effectiveness without significant side-effects was achieved when S(−)-nornicotine (sub-analgesic dose) was combined with a low-dose of the µ-opioid, morphine. These preclinical data suggest that S(−)-nornicotine may be of value, either alone or in combination with an opioid, for treatment of a broad-spectrum of pain (i.e. nociceptive, neuropathic, and mixed pain).     

Zebrafish as potential model for developmental neurotoxicity testing: A mini review

The zebrafish is a powerful toxicity model; biochemical assays can be combined with observations at a structural and functional level within one individual. This mini review summarises the potency of zebrafish as a model for developmental neurotoxicity screening, and its possibilities to investigate working mechanisms of toxicants. The use of zebrafish in toxicity research can ultimately lead to the refinement or reduction of animal use.     

A synthetic kainoid, (2S,3R,4R)-3-carboxymethyl-4-(phenylthio)pyrrolidine-2-carboxylic acid (PSPA-1) serves as a novel anti-allodynic agent for neuropathic pain

In spite of prominent progress in basic pain research, neuropathic pain remains a significant medical problem, because it is often poorly relieved by conventional analgesics. Thus this situation encourages us to make more sophisticated efforts toward the discovery of new analgesics. We previously showed that i.t. administration of acromelic acid-A (ACRO-A), a Japanese mushroom poison, provoked prominent tactile pain (allodynia) at an extremely low dose of 1 fg/mouse. In the present study we synthesized ACRO-A analogues (2S,3R,4R)-3-carboxymethyl-4-phenoxypyrrolidine-2-carboxylic acid (POPA-2) and (2S,3R,4R)-3-carboxymethyl-4-(phenylthio)pyrrolidine-2-carboxylic acid (PSPA-1) chemically and examined their ability to induce allodynia in conscious mice. Whereas POPA-2 induced allodynia at extremely low doses from 1 to 100 fg/mouse, similar to ACRO-A, PSPA-1 did not induce allodynia; rather, it inhibited the ACRO-A-induced allodynia with an ID(50) value (95% confidence limits) of 2.19 fg/mouse (0.04-31.8 fg/mouse). Furthermore, PSPA-1 relieved neuropathic pain produced by L5 spinal nerve transection on day 7 after the operation in a dose-dependent manner from 1 to 100 pg/mouse. In contrast, it did not affect thermal or mechanical nociception or inflammatory pain. PSPA-1 reduced the increase in neuronal nitric oxide synthase activity in the spinal cord of neuropathic pain mice assessed by NADPH-diaphorase histochemistry and blocked the allodynia induced by N-methyl-d-aspartate. These results demonstrate that PSPA-1 may represent a novel class of anti-allodynic agents for neuropathic pain acting by blocking the glutamate-nitric oxide pathway.