The Role of Adaptogens in Stress Management

Stress is a normal part of everyday life but it is important to be able to use tools for its management otherwise chronic stress, if left untreated, can lead to a variety of stress related illnesses including hypertension, heart disease, anxiety, depression, memory impairment and chronic fatigue syndrome. The aim of this literature review is to summarise and critically analyse research conducted on the adaptogenic herbs Withania somnifera, Panax ginseng, Eleutherococcus senticosus, Schisandra chinensis, Glycyrrhiza glabra, Rhodiola rosea, Bacopa monniera and Centella asiatica. The mechanism of adaptogens appears to involve the hypothalamic pituitary adrenal axis with resultant decreases or normalising of nitric oxide and cortisol, which are increased during times of stress. Most adaptogens also have anxiolytic and antioxidant properties and these have been attributed to their adaptogenic effect. Methods: The online databases PUBMED, PROQUEST, EBSCO and the Directory of Open Access Journals were searched to obtain peer-reviewed journal articles on adaptogens. The Library of the National Herbalists Association of Australia was also searched. Most studies used animal experimental models but some limited human clinical trials have been conducted. Fourteen studies using animal experimental models were identified and these have been summarised in Table 1. Twelve human clinical trials were identified and these have been summarised in Table 2. Results and conclusions: Withania somnifera appears to be the most commonly used, and extensively studied, adaptogen followed closely by Panax ginseng and Eleutherococcus senticosus. Schisandra chinensis is an extensively used adaptogen in Traditional Chinese Medicine (TCM). Other herbs studied that show adaptogenic activity include Rhodiola rosea, Glycyrrhiza glabra, Bacopa monniera and Centella asiatica, with the latter two more specific in improving memory. Most studies on adaptogens have used animal experimental models and whilst positive benefits have been shown, more large scale human clinical trials are needed.