【作者】 魏鹏；

【导师】 秦路平； 黄宝康； 张巧艳；

【作者基本信息】 第二军医大学 ， 生药学， 2008， 硕士

【摘要】 疼痛（pain）是一种复杂的生理心理活动,是临床上最常见的症状之一。根据国际疼痛研究会（IASP）对疼痛（pain）的定义:“一种不愉快的感觉和实际的或潜在的组织损伤所引发的情感经历;或者就这一损伤所做的描述”。疼痛可以理解为机体受到来自内外环境的伤害性刺激时出现的一种伴有情绪反应的病理生理过程,常会使患者遭受各种心里痛苦,如:惊慌、害怕、焦虑、悲伤、愤怒、烦躁、失眠等。同时它对于机体的影响也是多方面的,从局部到整体功能,严重者还可以导致生理功能紊乱,甚至可以引发疼痛性休克,而某些长期的剧烈疼痛,对机体已成为一种难以忍受的折磨。目前临床上用于疼痛治疗的药物主要有以下几类:阿片类镇痛药;中枢作用的非阿片类镇痛药;外周作用的镇痛药;复方抗炎镇痛药。目前临床上具有镇痛活性的西药因其化学成分单一、有毒副作用、安全性不高、有一定的成瘾性等缺点而导致其临床使用的局限性。中药和天然产物药作用机制复杂,安全性高,疗效确切,长期使用毒副作用小,从天然药物中寻找高效、低毒、无依赖性的镇痛新药已成为新的发展趋势。绵萆薢是我国常用的传统中药材,始出于《神农本草经》,列为中品,具有祛风,除湿的功能,临床用于治疗尿路感染、小便混浊、乳糜尿、白带过多及风湿性关节炎等症。我国2005版《中国药典》收载了三种萆薢,分为两个品名:（1）粉萆薢Dioscoreacollettii Hook.f.var.hypogiauca（2）绵萆薢相下收两种:绵萆薢Dioscorea septemlobaThunb.或福州薯蓣Dioscorea futschauensis Uline ex R.Kunth。绵萆薢Dioscoreaseptemloba Thunb.在我国东南诸省都有分布,主要产于浙江、福建、江西、湖南、湖北西南部、广西东北部、广东北部及贵州西部等省,生于海拔450—750米的山地疏林或灌木从中。近年来,关于绵萆薢的化学成分和药理作用的文献报道很多。从植物绵萆薢的根茎的乙醇提取物中分离得到了很多甾体皂苷类的化合物:薯蓣皂苷、薯蓣皂苷元、纤细薯蓣苷、原新薯蓣皂苷、原薯蓣皂甙、原新纤细薯蓣苷、原纤细薯蓣苷等,以及一些木脂素等其他的化合物成分。这些化学成分具有多种生物活性:抗肿瘤细胞活性、抗稻瘟霉活性、镇痛抗炎活性和抗骨质疏松的作用等。临床使用绵萆薢的祛风除湿,舒经通络功效来治疗尿路感染、小便混浊、乳糜尿、白带过多及风湿性关节炎、尿道炎、慢性前列腺炎。可见绵萆薢具有镇痛抗炎的临床使用功效,但是目前关于绵萆薢的镇痛药理活性以及镇痛作用机制的文献尚未报道。应用镇痛药理方法学对其总提物、氯仿部位提取物和正丁醇部位提取物进行了镇痛药理活性研究,采用经典的小鼠醋酸扭体法和福尔马林实验等对绵萆薢的乙醇提任铩⒙确虏课惶崛∥镆约罢〈疾课惶崛∥锝幸├砘钚陨秆?结果显示皂苷类成份具有良好的镇痛效果。我们对植物绵萆薢的根茎进行了乙醇提取,并对其乙醇提取物应用石油醚、氯仿、乙酸乙酯和正丁醇进行了分步骤萃取,并进一步通过活性导向对于目标化合物进行了分离和纯化:利用硅胶、sephadex LH-20、反向硅胶及HPLC等分离手段,从绵萆薢氯仿部位提取物中分离4个化合物,鉴定了3个化合物,主要为甾醇类化合物;从正丁醇部位分离得到5个化合物,鉴定了5个化合物,主要是甾体皂苷类化合物。应用理化常数测定和现代光谱技术(UV,IR,MS,¹H-NMR,¹³C-NMR)对这个8个化合物进行了鉴定。实验结果表明:受试小鼠口服给药剂量为0.5g/kg,2g/kg和8g/kg绵萆薢总提取物后,对腹腔注射醋酸溶液、足底皮下注射福尔马林溶液引发的疼痛以及在小鼠热板实验中对热刺激引发的疼痛的耐受性有显著提高;在二甲苯致小鼠耳肿胀实验中,总提物的高、中剂量都具有显著的局部抗炎作用。在小鼠热板拮抗实验中,和阳性拮抗组对比,发现受试组给拮抗剂后,出现与阳性拮抗组类似的实验结果,推测绵萆薢总提物的镇痛药理作用机制可能与中枢阿片受体类药物相同,还需要进一步的研究深入和探索。更多还原

【Abstract】 In accordance with the International Association for the Study of Pain,pain has been defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage,or described in terms of such damage.The pain appears widely in various kinds of diseases in clinic.Patients with intense and unrelenting pain need effective and potent analgesic agents.So it is very important to use analgesic exactly to control pain effectively.Because it can release the pain of the diseases,improve the life quality,at the same moment give the patients a comfort and extra confidence to fight with the diseases.According to the mechanism of pharmacological effect,analgesic agents are generally divided into opioid analgesics,such as alkaloid morphine,and non-steroidal anti-inflammatory drugs(NSAID),like aspirin.The opioid analgesics have some side effects such as addiction or respiratory depression and the NSAID has side effects to damage gastrointestinal tract.So it is necessary to search for new effective and nontoxic analgesics in plant-derived secondary metabolites from the natural products.Dioscorea septemloba Thunb.,a plant of Dioscorea genus,is widely distributed in the provinces of the southeast in China,snch as Zhejinag、Fujian、Jiangxi、Hunan、Guangdong and Guangxi and were used to treat chronic prostatitis,nonliquefaction of semem,osteoarthritis,osteoporosis,rheumatism and atrophic arthritis.Dioscorea septemloba Thunb.contain many kinds of chemical compounds, including steroidal glycosides,steroidal sapogenins,diarylheptanoids,lignans and etc.It is proved to have antiatheroscleorotic,antiosteoporotic and anti-tumor activities.The ethanol extract from Dioscorea septemloba Thunb.was evaluated on antinociceptive activity in mice using chemical and thermal models of nociception.Given orally,the ethanol extract、the n-butanol fraction and the chloroform fraction produced significant inhibitions on chemical nociception induced by intraperitoneal acetic acid and subplantar formalin or capsaicin injections and on thermal nociception in the tail-flick test and in the hot plate test.Dioscorea septemloba Thunb.was under bioassay-guided isolation,nine compounds were isolated from the ethanol extract of it by using column chromatography of silica gel,Sephadex LH-20,ODS and HPLC.Four compounds were isolated from the chloroform soluble fraction,and the other five compounds were isolated from the n-butanol soluble fraction.Their structures of the eight compounds were elucidated on the basis of chemical and NMR spectral methods as:(1)β-sitosterol;(2)β-carotene;(3) stigmasterol;(5) dioscin;(6) diosgenin;(7) methyl protodioscin;(8) spongioside A;(9) piperitol.更多还原