1.1 INTRODUCTION
The first use of medicinal herbs is lost in the mist of time. Man has always aspired to maintain or achieve a state of psychosomatic wellbeing and has therefore used naturally occurring substances of vegetables, animals, or mineral origin in order to alle- viate pain and suffering or to obtain therapeutic effects in the case of illness.
While acknowledging the important role of modern pharmacology and synthetic drugs in controlling major diseases, we consider that even now there is a need and a place for medicinal herbs in medicine and as such, a better exploitation of their therapeutic potential is necessary. In fact, unlike a single active principle in synthetic drugs, one or more active principles are present in medicinal herbs or plants and they may interact favorably since they can have synergic effects which are not yet fully recognized.
Medicinal herbs may be administered to human beings in various ways and in a variety of pharmaceutical preparations (extracts, decoctions, tinctures, syrups, eye- washes, etc.). As with synthetic drugs, in order to obtain therapeutic effects and avoid harmful effects, it is of fundamental importance to use a range of the so-called “therapeutic doses.” When we increase the doses of drugs and medicinal herbs, they first become toxic and ultimately lethal. The range between therapeutic and toxic doses is called “therapeutic window.” If the therapeutic window is very narrow and if, as the doses are gradually increased, there is an immediate transition from therapeutic to toxic doses, we, in this case, define the substances as poisons. There are, therefore, drugs or herbs with a very high intrinsic potency which, if doses are increased slightly, can have toxic or lethal effects. Hence, it is essential to classify medicinal herbs based on the potency of the pharmacological activities and the toxicity of the active principles contained within them. In practice, while recognizing the value of treatment with traditional herbs, we should bear in mind that improper use can produce serious toxic effects.
Because of the increasingly pervasive subculture in modern society, according to which what is “natural” is good, every year, huge damage is caused by the inappropriate use of the so-called natural products. Recently, this was pointed out by the US Food and Drug Administration (FDA), which noted that there is a widespread abuse of the so-called dietary supplement in the United States.
In fact, approximately 123 million people use these products for various purposes, to combat obesity, to prevent cancer, to ease pain, to enhance sexual performance, to stimulate mood, concentration, and memory, to enhance immune responses, to increase muscle mass and physical performance, and so on.
So far, the FDA has registered about 2900 cases of toxic effects, including 104 deaths caused primarily by the abuse of Ephedra. According to the FDA, there is no quality control for the marketing of such herbs and most of them are adulterated by contamination (with herbicides, pesticides, heavy metals, dioxin, biphenyls, etc.). In the United States, the most widely used products are those based on ephedrine (Ephedra sinica), for which more than 1200 cases of toxic effects, including 70 deaths, have been reported.
The UK Government and the Committee on Drug Safety recently expressed deep concern about the low quality and safety standards of a number of medicinal herbs not registered as medicines in Great Britain, especially certain “ethnic medicinal herbs.” In particular, a toxic ingredient of Aristolochia, now banned, was found in traditional Chinese medicinal products, probably as a result of accidental or voluntary substitution. This plant contains a number of active principles (aristolochic acids) which are carcinogenic and capable of inducing nephrotoxicity, leading to renal insufficiency, as observed in some patients in Great Britain. Furthermore, the agency found toxic levels of arsenic and mercury in a number of traditional Chinese medicinal herbs, and it is worried about the illegal adulteration of creams produced from Chinese medicinal herbs containing steroids. Toxic effects, pharmacointolerance (allergies and idiosyncrasies) caused by medicinal herbs, and their interactions with other drugs are described in detail in Ref [1].
Against this background, it was logical for the European Union to establish a new legislation to safeguard the health of consumers by, on the one hand, setting high quality and safety standards for medicinal herbs and, on the other hand, stipulating the inclusion, on labeling and in package leaflets, of scientifically verified, simple, and clear information including the potential toxicity of medicinal herbs and possible interaction with food products and/or other medicines taken simultaneously. All of these were done as it is essential, while acknowledging the value and therapeutic usefulness of medicinal herbs, to both step up scientific research and proceed with caution in administering them.
REFERENCE
1. M. Elvin-Lewis, Journal of Ethnopharmacology, 75, 141–164, 2001.
Soure: Giacinto Bagetta, Marco Cosentino, Marie Tiziana Corasaniti, Shinobu Sakurada (2012); Herbal Medicines: Development and Validation of Plant-derived Medicines for Human Health; CRC Press
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