Block Keith I, Mead Mark N
Institute for Integrative Cancer Care and Block Center for Integrative Cancer Care, Evanston, Illinois 60201, USA.
Integr Cancer Ther. 2003 Sep;2(3):247-67. doi: 10.1177/1534735403256419.
Traditional herbal medicine provides several remedies for strengthening the body's resistance to illness through effects on immune system components. This review article examines 3 popular herbal immune stimulants that are often of interest to cancer patients. Echinacea, a native of North America, is widely used to prevent, or provide early treatment for, colds. Preclinical studies lend biological plausibility to the idea that echinacea works through immune mechanisms. Numerous clinical trials have been carried out on echinacea preparations: it appears that the extracts shorten the duration and severity of colds and other upper respiratory infections (URIs) when given as soon as symptoms become evident. However, trials of long-term use of echinacea as a preventive have not shown positive results. Ginseng has been studied in some depth as an antifatigue agent, but studies of immune mechanisms have not proceeded so far. Preclinical evidence shows some immune-stimulating activity. There have been several clinical trials in a variety of different diseases. Astragalus is the least-studied agent. There are some preclinical trials that show intriguing immune activity. The herbs discussed appear to have satisfactory safety profiles. Cancer patients may wish to use these botanicals to inhibit tumor growth or to boost resistance to infections. However, passive immunotherapy with herbs, with no mechanism to expose tumor antigens, is unlikely to be effective in inhibiting tumor growth. Although the margin of safety for these herbs is large, more research is needed to demonstrate the clear value of using herbs to improve resistance to infections.
传统草药通过对免疫系统成分产生作用，提供了多种增强机体抗病能力的疗法。这篇综述文章研究了3种癌症患者常感兴趣的流行草药免疫刺激剂。紫锥菊原产于北美，被广泛用于预防感冒或对感冒进行早期治疗。临床前研究从生物学角度支持了紫锥菊通过免疫机制发挥作用的观点。针对紫锥菊制剂已开展了大量临床试验：当症状一出现就服用时，其提取物似乎能缩短感冒和其他上呼吸道感染（URI）的病程并减轻其严重程度。然而，长期使用紫锥菊作为预防措施的试验尚未显示出积极效果。人参作为一种抗疲劳剂已得到了一定程度的研究，但对其免疫机制的研究尚未深入开展。临床前证据显示出一些免疫刺激活性。针对多种不同疾病已开展了多项临床试验。黄芪是研究最少的药物。一些临床前试验显示出了有趣的免疫活性。所讨论的这些草药似乎具有令人满意的安全性。癌症患者可能希望使用这些植物药来抑制肿瘤生长或增强抗感染能力。然而，没有机制来暴露肿瘤抗原的草药被动免疫疗法不太可能有效抑制肿瘤生长。尽管这些草药的安全范围很大，但仍需要更多研究来证明使用草药提高抗感染能力的明确价值。
