2007年03月02日14:23英 | 大 | 中 | 小
中医一直通过搭配使用各种草药来给人治病。如果草药熬出的汤汁能够治疗某种疾病，为什么还要劳神费力地写出这一药剂的分子式呢？它管用，这就够了。
而美国食品和药物管理局(FDA)的看法却恰恰相反。这一全球最严格的药监机构数十年来一直对批准草药上市销售的申请嗤之以鼻。西方药理学的研究重点是找出能够治疗疾病的单一化合物。辉瑞(Pfizer)和默克(Merck)等制药公司经常耗资数十亿美元对成千上万种化合物逐一进行验证，以找出究竟哪一种才是治疗某种疾病的独门妙器。
东西方的这种差别可以浓缩成一个简单的问题：在你治病时，是像西方那样采取一弹致命的方式，用一种其疗效你已了然于心的化合物直击疾病的命门，还是像中国那样采用打散弹枪的方式，全面开花，只要能击中目标就行？
FDA对后一种方式不太接受。该机构将衡量其他药品的标准生硬地套用在草药上，要求药品开发者找出草药中究竟是哪一种成分能够治病，并证明其有效性。在美国，中药与用银杏和紫锥菊等植物制成的药用品只能在超市中与保健食品摆在一起，不得进入药店销售。
不过近年来，FDA对中国方式的接受程度已有所提高。根据它在2004年6月新发布的指导原则，制药公司已能较容易地将草药开发成西药。
去年底，FDA在新的审批体系实施后首次批准一种植物药上市销售，这种名为Polyphenon E的药膏用于治疗性病疣，它用绿茶制成。
这一指导原则中有一项重要的政策变更，今后希望用植物提取物开发处方药的公司只需提纯出一种有效的植物提取物即可，这一提纯物中可能包含有成百上千种化合物，厂家不再需要一一指出每一种化合物的药效。FDA的植物药评审小组负责人Shaw T. Chen说，替代性药品能够治病的事例是如此之多，人们必须拿出新的验证办法，不能只围着一个小分子式打转转。
新政策的实施使向FDA提交的新药上市申请大幅增长，并导致FDA先后批准约250种植物药进入临床试验阶段，这些新药多数是以传统中药为基础开发的。
FDA甚至还专门建立了一个办事处来受理这类申请，并聘用了接受过草药学教育的专家来充实这一机构。出生于中国的窦金辉就是FDA新设植物药审评小组一名药品评审师，他毕业于北京中医药大学。
现在还难以预测向FDA提出的其他植物药申请会有何种命运。这些草药适用的临床试验标准仍然未变。对制药公司来说，要想验证这些草药的有效性仍然很困难。
以英国的小型药物研发公司Phynova为例，FDA已批准它对一种治疗肝炎的植物药进行测试，这一药物由四种不同的植物制成。
每一种植物的萃取物都包含几百至上千种化合物，所以要找出究竟是哪一种化学物质产生了疗效是很困难的。Phynova的首席执行长罗伯特•米勒(Robert Miller)说，有些人可能要穷其一生才能完成这项工作。
用包含多种化合物的药品同时攻击多个目标有一大优势。人体和试图侵入人体的病菌会进化出几层富余的自我保护层，其作用相当于停电时的应急发电机。
这一现象非常有助于解释为什么一直难以开发出一种十分有效的减肥药。我们人体抵御饥饿的方式有多种，比如说当人吃下抑制食欲的减肥药时，人体通常会通过放慢新陈代谢来加以应对。如果饥饿感太容易克服，那么人类在进化过程中就很容易死于饥馑。
中医药则是多种药用成分和治疗手段的聚合，从针灸疗法到鹿鞭茶，几乎无所不包。如果不能完全了解药物中某种成分的治病机理，就难以确保药物的安全性或防止其产生副作用。有充足的理由对许多中医药疗法产生质疑，过分相信所谓替代疗法也是不足取的。
据FDA的植物药评审小组负责人Shaw T. Chen说，性病疣治疗药物Polyphenon E中大概含有10或20种主要的活性成分和数百种化合物。他说，植物药中可能存在多种活性成分，它们构成的多种治疗体系有可能在治疗疾病方面发挥协同效应，但这一看法仍有待证实。
Nicholas Zamiska
Taking the Chinese Approach
2007年03月02日14:23汉 | 大 | 中 | 小
Chinese doctors have long tinkered with combinations of herbs to cure disease. If a plant extract helped fight an infection, why bother trying to figure out which molecule did the trick? It worked, and that's what counted.
By contrast, the U.S. Food and Drug Administration, one of the world's most stringent drug watchdogs, for decades turned up its nose at applications for herbal medicines. The focus in Western pharmacology was finding the single compound to cure a disease. Pharmaceutical companies such as Pfizer and Merck spend billions of dollars combing through libraries of thousands of compounds to find the elusive blockbuster therapy.
The different approaches boil down to a simple question: Do you attack disease, as the Western world does, with a silver bullet -- a single compound whose potency you've pinpointed? Or do you use the Chinese method, aiming a group of agents at the disease target -- a shotgun approach?
The FDA was less receptive to latter method. The agency held botanical drugs to the same rigid standard as other therapies: find the part that works and prove it. Chinese medicines and other plant-based, or botanical, therapies, such as ginkgo and Echinacea, were sidelined to the dietary-supplement shelves at supermarkets and kept out of pharmacies.
But lately, the agency has edged closer toward the Chinese approach. In June 2004, it issued new guidelines making it easier for drug companies to turn herbal remedies into Western medicines.
Late last year, the FDA approved its first botanical drug under the new system, an ointment for genital warts called Polyphenon E, made from green-tea leaves.
The key change was requiring companies looking to convert plant-based extracts into marketable prescription drugs only to purify a plant extract, which could contain hundreds of compounds, rather than pinpointing a single one. 'There were so many stories of potentially new treatments in alternative medicine ... we needed a different approach than dealing with a single small molecule,' says Shaw T. Chen, botanical team leader at the FDA.
This new openness has led a surge of applications for approvals, and resulted in clearance for clinical trials for about 250 botanical drugs at some stage in the pipeline, most derived from traditional Chinese medicine.
The FDA even established a special office to deal with all those applications. To help run it, it has hired experts with training in herbal medicines. Jin hui Dou, for instance, a drug reviewer for the FDA's newly formed botanical review team, was born in China and earned a degree from the Beijing University of Chinese Medicine.
It's hard to predict how successful other applications are going to be. The standards for clinical testing of these herbal remedies in humans remain unchanged. And proving the effectiveness of these therapies overall is still a big challenge for the manufacturers.
Phynova, for example, a small, British drug-research company, has gotten the green light from the FDA to test a hepatitis botanical drug. The drug is a combination of four different plants: the roots of the astragalus and the Chinese salvia plants, the fruit of the schisandra plant, and milk thistle.
The number of compounds contained in each of those distilled extracts varies from several hundred to more than a thousand. So it's difficult to know which chemical is doing what. 'It could take somebody's whole life to figure that out,' says Robert Miller, Phynova's chief executive.
One advantage of attacking multiple targets with different compounds is that our body, and the pathogens that try to invade them, often evolve several layers of redundancy, the equivalent of a back-up power generator that flicks on when a fuse blows.
That goes a long way in explaining why it's been so difficult to come up with a powerful antiobesity drug. There are multiple ways our bodies register hunger. When patients are given appetite-suppressants, for example, their bodies often compensate by slowing down their metabolism. If hunger were easy to shut off, evolving human beings could easily have died of starvation.
Chinese medicine encompasses a huge swath of treatments and practices -- everything from acupuncture to remedies such as dried deer penis pulverized and taken as tea. An incomplete understanding of how a medicine works can make it harder to ensure its safety or to predict side effects. And there are good reasons to doubt many therapies, as a well as a danger of fetishizing so-called alternative approaches.
Polyphenon, the genital warts remedy, probably has 10 or 20 major active components and hundreds of molecules, according to Dr. Chen. 'There's a theoretical possibility that there are multiple active ingredients in botanicals that act on multiple systems that have synergistic effects,' he says. 'But that remains to be proved.'
Nicholas Zamiska
对西医西药来说，这个新闻表明他们才刚刚开始有点明白过来，但未来的路还很漫长。
看着真让人觉得可怜。
个人认为,中草药的成分复杂,加工方式,产地等多种影响因素的不同可以导致很多性状的不同,也直接影响治疗效果.所以单独研究还是很有必要的.但以既往西方的眼光和标准来上纲上线就没有意思了!
wqn1111 wrote:
个人认为,中草药的成分复杂,加工方式,产地等多种影响因素的不同可以导致很多性状的不同,也直接影响治疗效果.所以单独研究还是很有必要的.但以既往西方的眼光和标准来上纲上线就没有意思了!
你去跟FDA说
学习了.
micalfan1972 wrote:
你去跟FDA说
发表看法而已,又不要求你对我的话去上纲上线,你急什么啊
我们的SFDA如果看到这篇报道，新药标准可能又该变了。
yy7200 wrote:
我们的SFDA如果看到这篇报道，新药标准可能又该变了。
多么亦步亦趋的官员们啊，呵呵。
Post is deleted
knewman wrote:
仔细读了, Polyphenon E就像青蒿素一样, 是从植物中提取出来的化合物, 和阴阳八卦无关.
>
所以说他们的路还很漫长。
东西方的这种差别可以浓缩成一个简单的问题：在你治病时，是像西方那样采取一弹致命的方式，用一种其疗效你已了然于心的化合物直击疾病的命门，还是像中国那样采用打散弹枪的方式，全面开花，只要能击中目标就行？
搂主您好，上述比喻欠恰当，中医中药的治病理论还不能只说成是打散弹，这里比散弹要复杂得多，可以说西医与中医根本就放不在一起，不存在可比性，在将来我们会看到随着我中华民族的文化复兴，洋鬼子会承认并佩服中医药博大精深的理论，到时候老外会飘洋过海到我中华大地求医问药。
zhou6529 wrote:
东西方的这种差别可以浓缩成一个简单的问题：在你治病时，是像西方那样采取一弹致命的方式，用一种其疗效你已了然于心的化合物直击疾病的命门，还是像中国那样采用打散弹枪的方式，全面开花，只要能击中目标就行？
搂主您好，上述比喻欠恰当，中医中药的治病理论还不能只说成是打散弹，这里比散弹要复杂得多，可以说西医与中医根本就放不在一起，不存在可比性，在将来我们会看到随着我中华民族的文化复兴，洋鬼子会承认并佩服中医药博大精深的理论，到时候老外会飘洋过海到我中华大地求医问药。
没错。