Herbal Medicinal Products of Current Interest

Echinacea

Echinacea is widely used throughout Europe for the prevention and treatment of colds and other upper respiratory tract infections. A recent Cochrane review of 16 clinical trials has reported that the overall results suggest that some products may have an effect greater than placebo, but that overall the results were inconclusive (see Echinacea).⁽¹¹⁸⁾

Garlic

Numerous studies and systematic reviews have investigated the effects of garlic preparations in lowering raised serum cholesterol concentrations (see Garlic). Generally, the studies report beneficial results for garlic. However the evidence at present is insufficient to recommend garlic as routine treatment for hypercholesterolaemia. One of the major problems in assessing the evidence available on garlic is the wide variation in the chemical composition of the products available, compared with fresh garlic. Further controlled studies are needed using standardised preparations to investigate efficacy in reducing serum lipids, blood pressure, platelet aggregation and antimicrobial activity (see Garlic).

Ginger

Some clinical studies have reported ginger to be an effective prophylactic against motion sickness, although subsequent studies have found ginger to be ineffective (see Ginger).

Ginkgo

Ginkgo is widely used in France and Germany in authorised herbal medicinal products for the treatment of circulatory insufficiencies (peripheral and cerebral). Currently, no licensed herbal medicinal products containing ginkgo are available in the UK.

Several systematic reviews have been carried out analysing the available evidence on the effects of ginkgo in cerebral insufficiency, dementia, tinnitus and intermittent claudication (see Ginkgo). Overall the results suggest some beneficial effects, but further studies are needed.

Ginseng

Ginseng is widely renowned for its adaptogenic properties in Eastern countries, where it is used to help the body cope with stress and fatigue, and to promote recovery from illness or imbalance such as hypertension or hypoglycaemia. Generally, it is only recommended to be used for certain individuals with specific illnesses. By comparison, in the UK, ginseng is mainly self–administered and taken in the form of tablets or capsules containing dried extracts of the root. Ginseng products available in the UK are sold as food supplements, often in combination with vitamins and minerals. A wealth of research describing a wide range of pharmacological activities, particularly on the hypothalamic and pituitary regions of the brain, has been documented for ginseng (see Ginseng, Eleutherococcus).

Saw palmetto

Saw palmetto is widely used in Europe, particularly in Germany, for symptoms associated with benign prostatic hypertrophy (BPH). In the UK, saw palmetto is licensed in a number of products for the symptomatic relief of short–term, male urinary discomfort. Results of clinical trials indicate that saw palmetto is a potential agent for the symptomatic treatment of BPH (see Saw Palmetto).

Valerian

Valerian is widely used in Europe for nervous tension and for promoting sleep. The therapeutic indications proposed by the EMEA HMPWP include relief of temporary, mild nervous tension and temporary difficulty in falling asleep.⁽¹⁹⁾ A systematic review of randomised, double–blind, placebo–controlled trials of valerian reported inconsistencies in methodology between studies, and that the evidence for efficacy was inconclusive (see Valerian). It is unclear whether the active principles in valerian are associated with the volatile oil, the iridoid components termed valepotriates or with some other, as yet unidentified, group of constituents.