Goel V, Lovlin R, Barton R, Lyon M R, Bauer R, Lee T D G, Basu T K
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.
J Clin Pharm Ther. 2004 Feb;29(1):75-83. doi: 10.1111/j.1365-2710.2003.00542.x.
Recently, echinacea has regained popularity as one of the treatments chosen most commonly by consumers with the expectation that it will reduce the severity and duration of the common cold. However, the results from a limited number of clinical trials for this application have thus far been inconclusive. This incongruity may be the result of investigators utilizing poorly standardized echinacea products, likely devoid of sufficient quantities of active constituents necessary to exert a definitive clinical effect. Therefore, a formulation containing alkamides, cichoric acid, and polysaccharides at concentrations of 0.25, 2.5, and 25 mg/mL, respectively, was prepared from freshly harvested Echinacea purpurea plants (commercially available as Echinilin, Natural Factors Nutritional Products, Inc., Vancouver, BC, Canada). The objective of this study was to test the efficacy of this highly standardized formulation in reducing the severity and duration of symptoms of a naturally acquired common cold.
In a randomized, double-blind, placebo-controlled trial, 282 subjects aged 18-65 years with a history of two or more colds in the previous year, but otherwise in good health, were recruited. The subjects were randomized to receive either echinacea or placebo. They were instructed to start the echinacea or placebo at the onset of the first symptom related to a cold, consuming 10 doses the first day and four doses per day on subsequent days for 7 days. Severity of symptoms (10-point scale: 0, minimum; 9, maximum) and dosing were recorded daily. A nurse examined the subjects on the mornings of days 3 and 8 of their cold.
A total of 128 subjects contracted a common cold (59 echinacea, 69 placebo). The total daily symptom scores were found to be 23.1% lower in the echinacea group than in placebo in those who followed all elements of the study protocol (P<0.01). Throughout the treatment period, the response rate to treatments was greater in the echinacea group. A few adverse event profiles were observed in both groups.
Early intervention with a standardized formulation of echinacea resulted in reduced symptom severity in subjects with naturally acquired upper respiratory tract infection. Further studies with larger patient populations appear to be warranted.
最近，紫锥菊作为消费者最常选用的治疗方法之一再度受到欢迎，人们期望它能减轻普通感冒的严重程度并缩短病程。然而，针对这一用途的有限数量临床试验的结果迄今尚无定论。这种不一致可能是由于研究人员使用了标准化程度低的紫锥菊产品，这些产品可能缺乏发挥明确临床效果所需的足够数量的活性成分。因此，从新鲜采摘的紫松果菊植物（在加拿大不列颠哥伦比亚省温哥华市的Natural Factors Nutritional Products, Inc.以Echinilin的商品名上市）中制备了一种分别含有浓度为0.25、2.5和25 mg/mL的烷酰胺、菊苣酸和多糖的制剂。本研究的目的是测试这种高度标准化制剂减轻自然感染普通感冒症状的严重程度和缩短病程的疗效。
在一项随机、双盲、安慰剂对照试验中，招募了282名年龄在18至65岁之间、上一年有两次或更多次感冒史但其他方面健康的受试者。受试者被随机分配接受紫锥菊或安慰剂治疗。他们被指示在与感冒相关的首个症状出现时开始服用紫锥菊或安慰剂，第一天服用10剂，随后7天每天服用4剂。每天记录症状严重程度（采用10分制：0分为最低；9分为最高）和用药情况。一名护士在受试者感冒的第3天和第8天上午对其进行检查。
共有128名受试者患上普通感冒（59名服用紫锥菊，69名服用安慰剂）。在遵循研究方案所有要素的受试者中，紫锥菊组的每日症状总评分比安慰剂组低23.1%（P<0.01）。在整个治疗期间，紫锥菊组对治疗的反应率更高。两组均观察到一些不良事件情况。
对紫锥菊标准化制剂进行早期干预可减轻自然获得性上呼吸道感染受试者的症状严重程度。似乎有必要对更多患者群体进行进一步研究。
