Canadian Medical Association Journal 1996; 155: 155
The use of plants as a source of medicinal products is not new, even to Western medicine. Salicylic acid, derived from willow bark, has been used since ancient times to reduce fever and pain. Extracts of the common foxglove were used to treat dropsy long before the active product, digitalis, was isolated and proven scientifically to improve the functioning of the failing heart. Only a few decades ago, Canadian endocrinologist Robert Noble and his colleagues tested extracts of Vinca rosea to determine whether they had antiglycemic properties, only to find that the extracts had powerful and useful antineoplastic properties. That other herbal or botanical medicines may yet prove to have therapeutic value, I have no doubt.
But a problem arises when unproven herbal products flood the market and are advertised as having medicinal properties backed by vague, unsubstantiated claims. Even worse, control of herbal medicines has been so lax that the potency of the products may vary substantially, and in some cases the products have contained contaminants that are just plain toxic.
The entry of traditional pharmaceutical firms into the herbal medicine business is a mixed blessing. On the one hand, some firms have made substantial efforts to isolate and standardize the quality of the active ingredients. On the other hand, I have already found labels on herbal medicines produced by well-known firms to carry vague, unsubstantiated claims of therapeutic effectiveness.
More control of the herbal medicine business is obviously essential. Until that happens, caveat emptor!